1 //===-- DAGCombiner.cpp - Implement a DAG node combiner -------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This pass combines dag nodes to form fewer, simpler DAG nodes. It can be run
11 // both before and after the DAG is legalized.
13 // This pass is not a substitute for the LLVM IR instcombine pass. This pass is
14 // primarily intended to handle simplification opportunities that are implicit
15 // in the LLVM IR and exposed by the various codegen lowering phases.
17 //===----------------------------------------------------------------------===//
19 #include "llvm/CodeGen/SelectionDAG.h"
20 #include "llvm/ADT/SetVector.h"
21 #include "llvm/ADT/SmallBitVector.h"
22 #include "llvm/ADT/SmallPtrSet.h"
23 #include "llvm/ADT/Statistic.h"
24 #include "llvm/Analysis/AliasAnalysis.h"
25 #include "llvm/CodeGen/MachineFrameInfo.h"
26 #include "llvm/CodeGen/MachineFunction.h"
27 #include "llvm/IR/DataLayout.h"
28 #include "llvm/IR/DerivedTypes.h"
29 #include "llvm/IR/Function.h"
30 #include "llvm/IR/LLVMContext.h"
31 #include "llvm/Support/CommandLine.h"
32 #include "llvm/Support/Debug.h"
33 #include "llvm/Support/ErrorHandling.h"
34 #include "llvm/Support/MathExtras.h"
35 #include "llvm/Support/raw_ostream.h"
36 #include "llvm/Target/TargetLowering.h"
37 #include "llvm/Target/TargetOptions.h"
38 #include "llvm/Target/TargetRegisterInfo.h"
39 #include "llvm/Target/TargetSubtargetInfo.h"
43 #define DEBUG_TYPE "dagcombine"
45 STATISTIC(NodesCombined , "Number of dag nodes combined");
46 STATISTIC(PreIndexedNodes , "Number of pre-indexed nodes created");
47 STATISTIC(PostIndexedNodes, "Number of post-indexed nodes created");
48 STATISTIC(OpsNarrowed , "Number of load/op/store narrowed");
49 STATISTIC(LdStFP2Int , "Number of fp load/store pairs transformed to int");
50 STATISTIC(SlicedLoads, "Number of load sliced");
54 CombinerAA("combiner-alias-analysis", cl::Hidden,
55 cl::desc("Enable DAG combiner alias-analysis heuristics"));
58 CombinerGlobalAA("combiner-global-alias-analysis", cl::Hidden,
59 cl::desc("Enable DAG combiner's use of IR alias analysis"));
62 UseTBAA("combiner-use-tbaa", cl::Hidden, cl::init(true),
63 cl::desc("Enable DAG combiner's use of TBAA"));
66 static cl::opt<std::string>
67 CombinerAAOnlyFunc("combiner-aa-only-func", cl::Hidden,
68 cl::desc("Only use DAG-combiner alias analysis in this"
72 /// Hidden option to stress test load slicing, i.e., when this option
73 /// is enabled, load slicing bypasses most of its profitability guards.
75 StressLoadSlicing("combiner-stress-load-slicing", cl::Hidden,
76 cl::desc("Bypass the profitability model of load "
81 MaySplitLoadIndex("combiner-split-load-index", cl::Hidden, cl::init(true),
82 cl::desc("DAG combiner may split indexing from loads"));
84 //------------------------------ DAGCombiner ---------------------------------//
88 const TargetLowering &TLI;
90 CodeGenOpt::Level OptLevel;
95 /// \brief Worklist of all of the nodes that need to be simplified.
97 /// This must behave as a stack -- new nodes to process are pushed onto the
98 /// back and when processing we pop off of the back.
100 /// The worklist will not contain duplicates but may contain null entries
101 /// due to nodes being deleted from the underlying DAG.
102 SmallVector<SDNode *, 64> Worklist;
104 /// \brief Mapping from an SDNode to its position on the worklist.
106 /// This is used to find and remove nodes from the worklist (by nulling
107 /// them) when they are deleted from the underlying DAG. It relies on
108 /// stable indices of nodes within the worklist.
109 DenseMap<SDNode *, unsigned> WorklistMap;
111 /// \brief Set of nodes which have been combined (at least once).
113 /// This is used to allow us to reliably add any operands of a DAG node
114 /// which have not yet been combined to the worklist.
115 SmallPtrSet<SDNode *, 64> CombinedNodes;
117 // AA - Used for DAG load/store alias analysis.
120 /// When an instruction is simplified, add all users of the instruction to
121 /// the work lists because they might get more simplified now.
122 void AddUsersToWorklist(SDNode *N) {
123 for (SDNode *Node : N->uses())
127 /// Call the node-specific routine that folds each particular type of node.
128 SDValue visit(SDNode *N);
131 /// Add to the worklist making sure its instance is at the back (next to be
133 void AddToWorklist(SDNode *N) {
134 // Skip handle nodes as they can't usefully be combined and confuse the
135 // zero-use deletion strategy.
136 if (N->getOpcode() == ISD::HANDLENODE)
139 if (WorklistMap.insert(std::make_pair(N, Worklist.size())).second)
140 Worklist.push_back(N);
143 /// Remove all instances of N from the worklist.
144 void removeFromWorklist(SDNode *N) {
145 CombinedNodes.erase(N);
147 auto It = WorklistMap.find(N);
148 if (It == WorklistMap.end())
149 return; // Not in the worklist.
151 // Null out the entry rather than erasing it to avoid a linear operation.
152 Worklist[It->second] = nullptr;
153 WorklistMap.erase(It);
156 void deleteAndRecombine(SDNode *N);
157 bool recursivelyDeleteUnusedNodes(SDNode *N);
159 SDValue CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
162 SDValue CombineTo(SDNode *N, SDValue Res, bool AddTo = true) {
163 return CombineTo(N, &Res, 1, AddTo);
166 SDValue CombineTo(SDNode *N, SDValue Res0, SDValue Res1,
168 SDValue To[] = { Res0, Res1 };
169 return CombineTo(N, To, 2, AddTo);
172 void CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO);
176 /// Check the specified integer node value to see if it can be simplified or
177 /// if things it uses can be simplified by bit propagation.
178 /// If so, return true.
179 bool SimplifyDemandedBits(SDValue Op) {
180 unsigned BitWidth = Op.getValueType().getScalarType().getSizeInBits();
181 APInt Demanded = APInt::getAllOnesValue(BitWidth);
182 return SimplifyDemandedBits(Op, Demanded);
185 bool SimplifyDemandedBits(SDValue Op, const APInt &Demanded);
187 bool CombineToPreIndexedLoadStore(SDNode *N);
188 bool CombineToPostIndexedLoadStore(SDNode *N);
189 SDValue SplitIndexingFromLoad(LoadSDNode *LD);
190 bool SliceUpLoad(SDNode *N);
192 /// \brief Replace an ISD::EXTRACT_VECTOR_ELT of a load with a narrowed
195 /// \param EVE ISD::EXTRACT_VECTOR_ELT to be replaced.
196 /// \param InVecVT type of the input vector to EVE with bitcasts resolved.
197 /// \param EltNo index of the vector element to load.
198 /// \param OriginalLoad load that EVE came from to be replaced.
199 /// \returns EVE on success SDValue() on failure.
200 SDValue ReplaceExtractVectorEltOfLoadWithNarrowedLoad(
201 SDNode *EVE, EVT InVecVT, SDValue EltNo, LoadSDNode *OriginalLoad);
202 void ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad);
203 SDValue PromoteOperand(SDValue Op, EVT PVT, bool &Replace);
204 SDValue SExtPromoteOperand(SDValue Op, EVT PVT);
205 SDValue ZExtPromoteOperand(SDValue Op, EVT PVT);
206 SDValue PromoteIntBinOp(SDValue Op);
207 SDValue PromoteIntShiftOp(SDValue Op);
208 SDValue PromoteExtend(SDValue Op);
209 bool PromoteLoad(SDValue Op);
211 void ExtendSetCCUses(const SmallVectorImpl<SDNode *> &SetCCs,
212 SDValue Trunc, SDValue ExtLoad, SDLoc DL,
213 ISD::NodeType ExtType);
215 /// Call the node-specific routine that knows how to fold each
216 /// particular type of node. If that doesn't do anything, try the
217 /// target-specific DAG combines.
218 SDValue combine(SDNode *N);
220 // Visitation implementation - Implement dag node combining for different
221 // node types. The semantics are as follows:
223 // SDValue.getNode() == 0 - No change was made
224 // SDValue.getNode() == N - N was replaced, is dead and has been handled.
225 // otherwise - N should be replaced by the returned Operand.
227 SDValue visitTokenFactor(SDNode *N);
228 SDValue visitMERGE_VALUES(SDNode *N);
229 SDValue visitADD(SDNode *N);
230 SDValue visitSUB(SDNode *N);
231 SDValue visitADDC(SDNode *N);
232 SDValue visitSUBC(SDNode *N);
233 SDValue visitADDE(SDNode *N);
234 SDValue visitSUBE(SDNode *N);
235 SDValue visitMUL(SDNode *N);
236 SDValue visitSDIV(SDNode *N);
237 SDValue visitUDIV(SDNode *N);
238 SDValue visitSREM(SDNode *N);
239 SDValue visitUREM(SDNode *N);
240 SDValue visitMULHU(SDNode *N);
241 SDValue visitMULHS(SDNode *N);
242 SDValue visitSMUL_LOHI(SDNode *N);
243 SDValue visitUMUL_LOHI(SDNode *N);
244 SDValue visitSMULO(SDNode *N);
245 SDValue visitUMULO(SDNode *N);
246 SDValue visitSDIVREM(SDNode *N);
247 SDValue visitUDIVREM(SDNode *N);
248 SDValue visitAND(SDNode *N);
249 SDValue visitANDLike(SDValue N0, SDValue N1, SDNode *LocReference);
250 SDValue visitOR(SDNode *N);
251 SDValue visitORLike(SDValue N0, SDValue N1, SDNode *LocReference);
252 SDValue visitXOR(SDNode *N);
253 SDValue SimplifyVBinOp(SDNode *N);
254 SDValue visitSHL(SDNode *N);
255 SDValue visitSRA(SDNode *N);
256 SDValue visitSRL(SDNode *N);
257 SDValue visitRotate(SDNode *N);
258 SDValue visitBSWAP(SDNode *N);
259 SDValue visitCTLZ(SDNode *N);
260 SDValue visitCTLZ_ZERO_UNDEF(SDNode *N);
261 SDValue visitCTTZ(SDNode *N);
262 SDValue visitCTTZ_ZERO_UNDEF(SDNode *N);
263 SDValue visitCTPOP(SDNode *N);
264 SDValue visitSELECT(SDNode *N);
265 SDValue visitVSELECT(SDNode *N);
266 SDValue visitSELECT_CC(SDNode *N);
267 SDValue visitSETCC(SDNode *N);
268 SDValue visitSIGN_EXTEND(SDNode *N);
269 SDValue visitZERO_EXTEND(SDNode *N);
270 SDValue visitANY_EXTEND(SDNode *N);
271 SDValue visitSIGN_EXTEND_INREG(SDNode *N);
272 SDValue visitSIGN_EXTEND_VECTOR_INREG(SDNode *N);
273 SDValue visitTRUNCATE(SDNode *N);
274 SDValue visitBITCAST(SDNode *N);
275 SDValue visitBUILD_PAIR(SDNode *N);
276 SDValue visitFADD(SDNode *N);
277 SDValue visitFSUB(SDNode *N);
278 SDValue visitFMUL(SDNode *N);
279 SDValue visitFMA(SDNode *N);
280 SDValue visitFDIV(SDNode *N);
281 SDValue visitFREM(SDNode *N);
282 SDValue visitFSQRT(SDNode *N);
283 SDValue visitFCOPYSIGN(SDNode *N);
284 SDValue visitSINT_TO_FP(SDNode *N);
285 SDValue visitUINT_TO_FP(SDNode *N);
286 SDValue visitFP_TO_SINT(SDNode *N);
287 SDValue visitFP_TO_UINT(SDNode *N);
288 SDValue visitFP_ROUND(SDNode *N);
289 SDValue visitFP_ROUND_INREG(SDNode *N);
290 SDValue visitFP_EXTEND(SDNode *N);
291 SDValue visitFNEG(SDNode *N);
292 SDValue visitFABS(SDNode *N);
293 SDValue visitFCEIL(SDNode *N);
294 SDValue visitFTRUNC(SDNode *N);
295 SDValue visitFFLOOR(SDNode *N);
296 SDValue visitFMINNUM(SDNode *N);
297 SDValue visitFMAXNUM(SDNode *N);
298 SDValue visitBRCOND(SDNode *N);
299 SDValue visitBR_CC(SDNode *N);
300 SDValue visitLOAD(SDNode *N);
301 SDValue visitSTORE(SDNode *N);
302 SDValue visitINSERT_VECTOR_ELT(SDNode *N);
303 SDValue visitEXTRACT_VECTOR_ELT(SDNode *N);
304 SDValue visitBUILD_VECTOR(SDNode *N);
305 SDValue visitCONCAT_VECTORS(SDNode *N);
306 SDValue visitEXTRACT_SUBVECTOR(SDNode *N);
307 SDValue visitVECTOR_SHUFFLE(SDNode *N);
308 SDValue visitSCALAR_TO_VECTOR(SDNode *N);
309 SDValue visitINSERT_SUBVECTOR(SDNode *N);
310 SDValue visitMLOAD(SDNode *N);
311 SDValue visitMSTORE(SDNode *N);
312 SDValue visitMGATHER(SDNode *N);
313 SDValue visitMSCATTER(SDNode *N);
314 SDValue visitFP_TO_FP16(SDNode *N);
316 SDValue visitFADDForFMACombine(SDNode *N);
317 SDValue visitFSUBForFMACombine(SDNode *N);
319 SDValue XformToShuffleWithZero(SDNode *N);
320 SDValue ReassociateOps(unsigned Opc, SDLoc DL, SDValue LHS, SDValue RHS);
322 SDValue visitShiftByConstant(SDNode *N, ConstantSDNode *Amt);
324 bool SimplifySelectOps(SDNode *SELECT, SDValue LHS, SDValue RHS);
325 SDValue SimplifyBinOpWithSameOpcodeHands(SDNode *N);
326 SDValue SimplifySelect(SDLoc DL, SDValue N0, SDValue N1, SDValue N2);
327 SDValue SimplifySelectCC(SDLoc DL, SDValue N0, SDValue N1, SDValue N2,
328 SDValue N3, ISD::CondCode CC,
329 bool NotExtCompare = false);
330 SDValue SimplifySetCC(EVT VT, SDValue N0, SDValue N1, ISD::CondCode Cond,
331 SDLoc DL, bool foldBooleans = true);
333 bool isSetCCEquivalent(SDValue N, SDValue &LHS, SDValue &RHS,
335 bool isOneUseSetCC(SDValue N) const;
337 SDValue SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
339 SDValue CombineConsecutiveLoads(SDNode *N, EVT VT);
340 SDValue CombineExtLoad(SDNode *N);
341 SDValue ConstantFoldBITCASTofBUILD_VECTOR(SDNode *, EVT);
342 SDValue BuildSDIV(SDNode *N);
343 SDValue BuildSDIVPow2(SDNode *N);
344 SDValue BuildUDIV(SDNode *N);
345 SDValue BuildReciprocalEstimate(SDValue Op);
346 SDValue BuildRsqrtEstimate(SDValue Op);
347 SDValue BuildRsqrtNROneConst(SDValue Op, SDValue Est, unsigned Iterations);
348 SDValue BuildRsqrtNRTwoConst(SDValue Op, SDValue Est, unsigned Iterations);
349 SDValue MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
350 bool DemandHighBits = true);
351 SDValue MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1);
352 SDNode *MatchRotatePosNeg(SDValue Shifted, SDValue Pos, SDValue Neg,
353 SDValue InnerPos, SDValue InnerNeg,
354 unsigned PosOpcode, unsigned NegOpcode,
356 SDNode *MatchRotate(SDValue LHS, SDValue RHS, SDLoc DL);
357 SDValue ReduceLoadWidth(SDNode *N);
358 SDValue ReduceLoadOpStoreWidth(SDNode *N);
359 SDValue TransformFPLoadStorePair(SDNode *N);
360 SDValue reduceBuildVecExtToExtBuildVec(SDNode *N);
361 SDValue reduceBuildVecConvertToConvertBuildVec(SDNode *N);
363 SDValue GetDemandedBits(SDValue V, const APInt &Mask);
365 /// Walk up chain skipping non-aliasing memory nodes,
366 /// looking for aliasing nodes and adding them to the Aliases vector.
367 void GatherAllAliases(SDNode *N, SDValue OriginalChain,
368 SmallVectorImpl<SDValue> &Aliases);
370 /// Return true if there is any possibility that the two addresses overlap.
371 bool isAlias(LSBaseSDNode *Op0, LSBaseSDNode *Op1) const;
373 /// Walk up chain skipping non-aliasing memory nodes, looking for a better
374 /// chain (aliasing node.)
375 SDValue FindBetterChain(SDNode *N, SDValue Chain);
377 /// Holds a pointer to an LSBaseSDNode as well as information on where it
378 /// is located in a sequence of memory operations connected by a chain.
380 MemOpLink (LSBaseSDNode *N, int64_t Offset, unsigned Seq):
381 MemNode(N), OffsetFromBase(Offset), SequenceNum(Seq) { }
382 // Ptr to the mem node.
383 LSBaseSDNode *MemNode;
384 // Offset from the base ptr.
385 int64_t OffsetFromBase;
386 // What is the sequence number of this mem node.
387 // Lowest mem operand in the DAG starts at zero.
388 unsigned SequenceNum;
391 /// This is a helper function for MergeStoresOfConstantsOrVecElts. Returns a
392 /// constant build_vector of the stored constant values in Stores.
393 SDValue getMergedConstantVectorStore(SelectionDAG &DAG,
395 ArrayRef<MemOpLink> Stores,
398 /// This is a helper function for MergeConsecutiveStores. When the source
399 /// elements of the consecutive stores are all constants or all extracted
400 /// vector elements, try to merge them into one larger store.
401 /// \return True if a merged store was created.
402 bool MergeStoresOfConstantsOrVecElts(SmallVectorImpl<MemOpLink> &StoreNodes,
403 EVT MemVT, unsigned NumElem,
404 bool IsConstantSrc, bool UseVector);
406 /// This is a helper function for MergeConsecutiveStores.
407 /// Stores that may be merged are placed in StoreNodes.
408 /// Loads that may alias with those stores are placed in AliasLoadNodes.
409 void getStoreMergeAndAliasCandidates(
410 StoreSDNode* St, SmallVectorImpl<MemOpLink> &StoreNodes,
411 SmallVectorImpl<LSBaseSDNode*> &AliasLoadNodes);
413 /// Merge consecutive store operations into a wide store.
414 /// This optimization uses wide integers or vectors when possible.
415 /// \return True if some memory operations were changed.
416 bool MergeConsecutiveStores(StoreSDNode *N);
418 /// \brief Try to transform a truncation where C is a constant:
419 /// (trunc (and X, C)) -> (and (trunc X), (trunc C))
421 /// \p N needs to be a truncation and its first operand an AND. Other
422 /// requirements are checked by the function (e.g. that trunc is
423 /// single-use) and if missed an empty SDValue is returned.
424 SDValue distributeTruncateThroughAnd(SDNode *N);
427 DAGCombiner(SelectionDAG &D, AliasAnalysis &A, CodeGenOpt::Level OL)
428 : DAG(D), TLI(D.getTargetLoweringInfo()), Level(BeforeLegalizeTypes),
429 OptLevel(OL), LegalOperations(false), LegalTypes(false), AA(A) {
430 auto *F = DAG.getMachineFunction().getFunction();
431 ForCodeSize = F->hasFnAttribute(Attribute::OptimizeForSize) ||
432 F->hasFnAttribute(Attribute::MinSize);
435 /// Runs the dag combiner on all nodes in the work list
436 void Run(CombineLevel AtLevel);
438 SelectionDAG &getDAG() const { return DAG; }
440 /// Returns a type large enough to hold any valid shift amount - before type
441 /// legalization these can be huge.
442 EVT getShiftAmountTy(EVT LHSTy) {
443 assert(LHSTy.isInteger() && "Shift amount is not an integer type!");
444 if (LHSTy.isVector())
446 return LegalTypes ? TLI.getScalarShiftAmountTy(LHSTy)
447 : TLI.getPointerTy();
450 /// This method returns true if we are running before type legalization or
451 /// if the specified VT is legal.
452 bool isTypeLegal(const EVT &VT) {
453 if (!LegalTypes) return true;
454 return TLI.isTypeLegal(VT);
457 /// Convenience wrapper around TargetLowering::getSetCCResultType
458 EVT getSetCCResultType(EVT VT) const {
459 return TLI.getSetCCResultType(*DAG.getContext(), VT);
466 /// This class is a DAGUpdateListener that removes any deleted
467 /// nodes from the worklist.
468 class WorklistRemover : public SelectionDAG::DAGUpdateListener {
471 explicit WorklistRemover(DAGCombiner &dc)
472 : SelectionDAG::DAGUpdateListener(dc.getDAG()), DC(dc) {}
474 void NodeDeleted(SDNode *N, SDNode *E) override {
475 DC.removeFromWorklist(N);
480 //===----------------------------------------------------------------------===//
481 // TargetLowering::DAGCombinerInfo implementation
482 //===----------------------------------------------------------------------===//
484 void TargetLowering::DAGCombinerInfo::AddToWorklist(SDNode *N) {
485 ((DAGCombiner*)DC)->AddToWorklist(N);
488 void TargetLowering::DAGCombinerInfo::RemoveFromWorklist(SDNode *N) {
489 ((DAGCombiner*)DC)->removeFromWorklist(N);
492 SDValue TargetLowering::DAGCombinerInfo::
493 CombineTo(SDNode *N, ArrayRef<SDValue> To, bool AddTo) {
494 return ((DAGCombiner*)DC)->CombineTo(N, &To[0], To.size(), AddTo);
497 SDValue TargetLowering::DAGCombinerInfo::
498 CombineTo(SDNode *N, SDValue Res, bool AddTo) {
499 return ((DAGCombiner*)DC)->CombineTo(N, Res, AddTo);
503 SDValue TargetLowering::DAGCombinerInfo::
504 CombineTo(SDNode *N, SDValue Res0, SDValue Res1, bool AddTo) {
505 return ((DAGCombiner*)DC)->CombineTo(N, Res0, Res1, AddTo);
508 void TargetLowering::DAGCombinerInfo::
509 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
510 return ((DAGCombiner*)DC)->CommitTargetLoweringOpt(TLO);
513 //===----------------------------------------------------------------------===//
515 //===----------------------------------------------------------------------===//
517 void DAGCombiner::deleteAndRecombine(SDNode *N) {
518 removeFromWorklist(N);
520 // If the operands of this node are only used by the node, they will now be
521 // dead. Make sure to re-visit them and recursively delete dead nodes.
522 for (const SDValue &Op : N->ops())
523 // For an operand generating multiple values, one of the values may
524 // become dead allowing further simplification (e.g. split index
525 // arithmetic from an indexed load).
526 if (Op->hasOneUse() || Op->getNumValues() > 1)
527 AddToWorklist(Op.getNode());
532 /// Return 1 if we can compute the negated form of the specified expression for
533 /// the same cost as the expression itself, or 2 if we can compute the negated
534 /// form more cheaply than the expression itself.
535 static char isNegatibleForFree(SDValue Op, bool LegalOperations,
536 const TargetLowering &TLI,
537 const TargetOptions *Options,
538 unsigned Depth = 0) {
539 // fneg is removable even if it has multiple uses.
540 if (Op.getOpcode() == ISD::FNEG) return 2;
542 // Don't allow anything with multiple uses.
543 if (!Op.hasOneUse()) return 0;
545 // Don't recurse exponentially.
546 if (Depth > 6) return 0;
548 switch (Op.getOpcode()) {
549 default: return false;
550 case ISD::ConstantFP:
551 // Don't invert constant FP values after legalize. The negated constant
552 // isn't necessarily legal.
553 return LegalOperations ? 0 : 1;
555 // FIXME: determine better conditions for this xform.
556 if (!Options->UnsafeFPMath) return 0;
558 // After operation legalization, it might not be legal to create new FSUBs.
559 if (LegalOperations &&
560 !TLI.isOperationLegalOrCustom(ISD::FSUB, Op.getValueType()))
563 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
564 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
567 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
568 return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
571 // We can't turn -(A-B) into B-A when we honor signed zeros.
572 if (!Options->UnsafeFPMath) return 0;
574 // fold (fneg (fsub A, B)) -> (fsub B, A)
579 if (Options->HonorSignDependentRoundingFPMath()) return 0;
581 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y) or (fmul X, (fneg Y))
582 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
586 return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
592 return isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI, Options,
597 /// If isNegatibleForFree returns true, return the newly negated expression.
598 static SDValue GetNegatedExpression(SDValue Op, SelectionDAG &DAG,
599 bool LegalOperations, unsigned Depth = 0) {
600 const TargetOptions &Options = DAG.getTarget().Options;
601 // fneg is removable even if it has multiple uses.
602 if (Op.getOpcode() == ISD::FNEG) return Op.getOperand(0);
604 // Don't allow anything with multiple uses.
605 assert(Op.hasOneUse() && "Unknown reuse!");
607 assert(Depth <= 6 && "GetNegatedExpression doesn't match isNegatibleForFree");
608 switch (Op.getOpcode()) {
609 default: llvm_unreachable("Unknown code");
610 case ISD::ConstantFP: {
611 APFloat V = cast<ConstantFPSDNode>(Op)->getValueAPF();
613 return DAG.getConstantFP(V, SDLoc(Op), Op.getValueType());
616 // FIXME: determine better conditions for this xform.
617 assert(Options.UnsafeFPMath);
619 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
620 if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
621 DAG.getTargetLoweringInfo(), &Options, Depth+1))
622 return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
623 GetNegatedExpression(Op.getOperand(0), DAG,
624 LegalOperations, Depth+1),
626 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
627 return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
628 GetNegatedExpression(Op.getOperand(1), DAG,
629 LegalOperations, Depth+1),
632 // We can't turn -(A-B) into B-A when we honor signed zeros.
633 assert(Options.UnsafeFPMath);
635 // fold (fneg (fsub 0, B)) -> B
636 if (ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(Op.getOperand(0)))
638 return Op.getOperand(1);
640 // fold (fneg (fsub A, B)) -> (fsub B, A)
641 return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
642 Op.getOperand(1), Op.getOperand(0));
646 assert(!Options.HonorSignDependentRoundingFPMath());
648 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y)
649 if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
650 DAG.getTargetLoweringInfo(), &Options, Depth+1))
651 return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
652 GetNegatedExpression(Op.getOperand(0), DAG,
653 LegalOperations, Depth+1),
656 // fold (fneg (fmul X, Y)) -> (fmul X, (fneg Y))
657 return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
659 GetNegatedExpression(Op.getOperand(1), DAG,
660 LegalOperations, Depth+1));
664 return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
665 GetNegatedExpression(Op.getOperand(0), DAG,
666 LegalOperations, Depth+1));
668 return DAG.getNode(ISD::FP_ROUND, SDLoc(Op), Op.getValueType(),
669 GetNegatedExpression(Op.getOperand(0), DAG,
670 LegalOperations, Depth+1),
675 // Return true if this node is a setcc, or is a select_cc
676 // that selects between the target values used for true and false, making it
677 // equivalent to a setcc. Also, set the incoming LHS, RHS, and CC references to
678 // the appropriate nodes based on the type of node we are checking. This
679 // simplifies life a bit for the callers.
680 bool DAGCombiner::isSetCCEquivalent(SDValue N, SDValue &LHS, SDValue &RHS,
682 if (N.getOpcode() == ISD::SETCC) {
683 LHS = N.getOperand(0);
684 RHS = N.getOperand(1);
685 CC = N.getOperand(2);
689 if (N.getOpcode() != ISD::SELECT_CC ||
690 !TLI.isConstTrueVal(N.getOperand(2).getNode()) ||
691 !TLI.isConstFalseVal(N.getOperand(3).getNode()))
694 if (TLI.getBooleanContents(N.getValueType()) ==
695 TargetLowering::UndefinedBooleanContent)
698 LHS = N.getOperand(0);
699 RHS = N.getOperand(1);
700 CC = N.getOperand(4);
704 /// Return true if this is a SetCC-equivalent operation with only one use.
705 /// If this is true, it allows the users to invert the operation for free when
706 /// it is profitable to do so.
707 bool DAGCombiner::isOneUseSetCC(SDValue N) const {
709 if (isSetCCEquivalent(N, N0, N1, N2) && N.getNode()->hasOneUse())
714 /// Returns true if N is a BUILD_VECTOR node whose
715 /// elements are all the same constant or undefined.
716 static bool isConstantSplatVector(SDNode *N, APInt& SplatValue) {
717 BuildVectorSDNode *C = dyn_cast<BuildVectorSDNode>(N);
722 unsigned SplatBitSize;
724 EVT EltVT = N->getValueType(0).getVectorElementType();
725 return (C->isConstantSplat(SplatValue, SplatUndef, SplatBitSize,
727 EltVT.getSizeInBits() >= SplatBitSize);
730 // \brief Returns the SDNode if it is a constant integer BuildVector
731 // or constant integer.
732 static SDNode *isConstantIntBuildVectorOrConstantInt(SDValue N) {
733 if (isa<ConstantSDNode>(N))
735 if (ISD::isBuildVectorOfConstantSDNodes(N.getNode()))
740 // \brief Returns the SDNode if it is a constant float BuildVector
741 // or constant float.
742 static SDNode *isConstantFPBuildVectorOrConstantFP(SDValue N) {
743 if (isa<ConstantFPSDNode>(N))
745 if (ISD::isBuildVectorOfConstantFPSDNodes(N.getNode()))
750 // \brief Returns the SDNode if it is a constant splat BuildVector or constant
752 static ConstantSDNode *isConstOrConstSplat(SDValue N) {
753 if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N))
756 if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N)) {
757 BitVector UndefElements;
758 ConstantSDNode *CN = BV->getConstantSplatNode(&UndefElements);
760 // BuildVectors can truncate their operands. Ignore that case here.
761 // FIXME: We blindly ignore splats which include undef which is overly
763 if (CN && UndefElements.none() &&
764 CN->getValueType(0) == N.getValueType().getScalarType())
771 // \brief Returns the SDNode if it is a constant splat BuildVector or constant
773 static ConstantFPSDNode *isConstOrConstSplatFP(SDValue N) {
774 if (ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(N))
777 if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N)) {
778 BitVector UndefElements;
779 ConstantFPSDNode *CN = BV->getConstantFPSplatNode(&UndefElements);
781 if (CN && UndefElements.none())
788 SDValue DAGCombiner::ReassociateOps(unsigned Opc, SDLoc DL,
789 SDValue N0, SDValue N1) {
790 EVT VT = N0.getValueType();
791 if (N0.getOpcode() == Opc) {
792 if (SDNode *L = isConstantIntBuildVectorOrConstantInt(N0.getOperand(1))) {
793 if (SDNode *R = isConstantIntBuildVectorOrConstantInt(N1)) {
794 // reassoc. (op (op x, c1), c2) -> (op x, (op c1, c2))
795 if (SDValue OpNode = DAG.FoldConstantArithmetic(Opc, DL, VT, L, R))
796 return DAG.getNode(Opc, DL, VT, N0.getOperand(0), OpNode);
799 if (N0.hasOneUse()) {
800 // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one
802 SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT, N0.getOperand(0), N1);
803 if (!OpNode.getNode())
805 AddToWorklist(OpNode.getNode());
806 return DAG.getNode(Opc, DL, VT, OpNode, N0.getOperand(1));
811 if (N1.getOpcode() == Opc) {
812 if (SDNode *R = isConstantIntBuildVectorOrConstantInt(N1.getOperand(1))) {
813 if (SDNode *L = isConstantIntBuildVectorOrConstantInt(N0)) {
814 // reassoc. (op c2, (op x, c1)) -> (op x, (op c1, c2))
815 if (SDValue OpNode = DAG.FoldConstantArithmetic(Opc, DL, VT, R, L))
816 return DAG.getNode(Opc, DL, VT, N1.getOperand(0), OpNode);
819 if (N1.hasOneUse()) {
820 // reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) iff x+c1 has one
822 SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT, N1.getOperand(0), N0);
823 if (!OpNode.getNode())
825 AddToWorklist(OpNode.getNode());
826 return DAG.getNode(Opc, DL, VT, OpNode, N1.getOperand(1));
834 SDValue DAGCombiner::CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
836 assert(N->getNumValues() == NumTo && "Broken CombineTo call!");
838 DEBUG(dbgs() << "\nReplacing.1 ";
840 dbgs() << "\nWith: ";
841 To[0].getNode()->dump(&DAG);
842 dbgs() << " and " << NumTo-1 << " other values\n");
843 for (unsigned i = 0, e = NumTo; i != e; ++i)
844 assert((!To[i].getNode() ||
845 N->getValueType(i) == To[i].getValueType()) &&
846 "Cannot combine value to value of different type!");
848 WorklistRemover DeadNodes(*this);
849 DAG.ReplaceAllUsesWith(N, To);
851 // Push the new nodes and any users onto the worklist
852 for (unsigned i = 0, e = NumTo; i != e; ++i) {
853 if (To[i].getNode()) {
854 AddToWorklist(To[i].getNode());
855 AddUsersToWorklist(To[i].getNode());
860 // Finally, if the node is now dead, remove it from the graph. The node
861 // may not be dead if the replacement process recursively simplified to
862 // something else needing this node.
864 deleteAndRecombine(N);
865 return SDValue(N, 0);
869 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
870 // Replace all uses. If any nodes become isomorphic to other nodes and
871 // are deleted, make sure to remove them from our worklist.
872 WorklistRemover DeadNodes(*this);
873 DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New);
875 // Push the new node and any (possibly new) users onto the worklist.
876 AddToWorklist(TLO.New.getNode());
877 AddUsersToWorklist(TLO.New.getNode());
879 // Finally, if the node is now dead, remove it from the graph. The node
880 // may not be dead if the replacement process recursively simplified to
881 // something else needing this node.
882 if (TLO.Old.getNode()->use_empty())
883 deleteAndRecombine(TLO.Old.getNode());
886 /// Check the specified integer node value to see if it can be simplified or if
887 /// things it uses can be simplified by bit propagation. If so, return true.
888 bool DAGCombiner::SimplifyDemandedBits(SDValue Op, const APInt &Demanded) {
889 TargetLowering::TargetLoweringOpt TLO(DAG, LegalTypes, LegalOperations);
890 APInt KnownZero, KnownOne;
891 if (!TLI.SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO))
895 AddToWorklist(Op.getNode());
897 // Replace the old value with the new one.
899 DEBUG(dbgs() << "\nReplacing.2 ";
900 TLO.Old.getNode()->dump(&DAG);
901 dbgs() << "\nWith: ";
902 TLO.New.getNode()->dump(&DAG);
905 CommitTargetLoweringOpt(TLO);
909 void DAGCombiner::ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad) {
911 EVT VT = Load->getValueType(0);
912 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, VT, SDValue(ExtLoad, 0));
914 DEBUG(dbgs() << "\nReplacing.9 ";
916 dbgs() << "\nWith: ";
917 Trunc.getNode()->dump(&DAG);
919 WorklistRemover DeadNodes(*this);
920 DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 0), Trunc);
921 DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 1), SDValue(ExtLoad, 1));
922 deleteAndRecombine(Load);
923 AddToWorklist(Trunc.getNode());
926 SDValue DAGCombiner::PromoteOperand(SDValue Op, EVT PVT, bool &Replace) {
929 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Op)) {
930 EVT MemVT = LD->getMemoryVT();
931 ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
932 ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, PVT, MemVT) ? ISD::ZEXTLOAD
934 : LD->getExtensionType();
936 return DAG.getExtLoad(ExtType, dl, PVT,
937 LD->getChain(), LD->getBasePtr(),
938 MemVT, LD->getMemOperand());
941 unsigned Opc = Op.getOpcode();
944 case ISD::AssertSext:
945 return DAG.getNode(ISD::AssertSext, dl, PVT,
946 SExtPromoteOperand(Op.getOperand(0), PVT),
948 case ISD::AssertZext:
949 return DAG.getNode(ISD::AssertZext, dl, PVT,
950 ZExtPromoteOperand(Op.getOperand(0), PVT),
952 case ISD::Constant: {
954 Op.getValueType().isByteSized() ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
955 return DAG.getNode(ExtOpc, dl, PVT, Op);
959 if (!TLI.isOperationLegal(ISD::ANY_EXTEND, PVT))
961 return DAG.getNode(ISD::ANY_EXTEND, dl, PVT, Op);
964 SDValue DAGCombiner::SExtPromoteOperand(SDValue Op, EVT PVT) {
965 if (!TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, PVT))
967 EVT OldVT = Op.getValueType();
969 bool Replace = false;
970 SDValue NewOp = PromoteOperand(Op, PVT, Replace);
971 if (!NewOp.getNode())
973 AddToWorklist(NewOp.getNode());
976 ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
977 return DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, NewOp.getValueType(), NewOp,
978 DAG.getValueType(OldVT));
981 SDValue DAGCombiner::ZExtPromoteOperand(SDValue Op, EVT PVT) {
982 EVT OldVT = Op.getValueType();
984 bool Replace = false;
985 SDValue NewOp = PromoteOperand(Op, PVT, Replace);
986 if (!NewOp.getNode())
988 AddToWorklist(NewOp.getNode());
991 ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
992 return DAG.getZeroExtendInReg(NewOp, dl, OldVT);
995 /// Promote the specified integer binary operation if the target indicates it is
996 /// beneficial. e.g. On x86, it's usually better to promote i16 operations to
997 /// i32 since i16 instructions are longer.
998 SDValue DAGCombiner::PromoteIntBinOp(SDValue Op) {
999 if (!LegalOperations)
1002 EVT VT = Op.getValueType();
1003 if (VT.isVector() || !VT.isInteger())
1006 // If operation type is 'undesirable', e.g. i16 on x86, consider
1008 unsigned Opc = Op.getOpcode();
1009 if (TLI.isTypeDesirableForOp(Opc, VT))
1013 // Consult target whether it is a good idea to promote this operation and
1014 // what's the right type to promote it to.
1015 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
1016 assert(PVT != VT && "Don't know what type to promote to!");
1018 bool Replace0 = false;
1019 SDValue N0 = Op.getOperand(0);
1020 SDValue NN0 = PromoteOperand(N0, PVT, Replace0);
1024 bool Replace1 = false;
1025 SDValue N1 = Op.getOperand(1);
1030 NN1 = PromoteOperand(N1, PVT, Replace1);
1035 AddToWorklist(NN0.getNode());
1037 AddToWorklist(NN1.getNode());
1040 ReplaceLoadWithPromotedLoad(N0.getNode(), NN0.getNode());
1042 ReplaceLoadWithPromotedLoad(N1.getNode(), NN1.getNode());
1044 DEBUG(dbgs() << "\nPromoting ";
1045 Op.getNode()->dump(&DAG));
1047 return DAG.getNode(ISD::TRUNCATE, dl, VT,
1048 DAG.getNode(Opc, dl, PVT, NN0, NN1));
1053 /// Promote the specified integer shift operation if the target indicates it is
1054 /// beneficial. e.g. On x86, it's usually better to promote i16 operations to
1055 /// i32 since i16 instructions are longer.
1056 SDValue DAGCombiner::PromoteIntShiftOp(SDValue Op) {
1057 if (!LegalOperations)
1060 EVT VT = Op.getValueType();
1061 if (VT.isVector() || !VT.isInteger())
1064 // If operation type is 'undesirable', e.g. i16 on x86, consider
1066 unsigned Opc = Op.getOpcode();
1067 if (TLI.isTypeDesirableForOp(Opc, VT))
1071 // Consult target whether it is a good idea to promote this operation and
1072 // what's the right type to promote it to.
1073 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
1074 assert(PVT != VT && "Don't know what type to promote to!");
1076 bool Replace = false;
1077 SDValue N0 = Op.getOperand(0);
1078 if (Opc == ISD::SRA)
1079 N0 = SExtPromoteOperand(Op.getOperand(0), PVT);
1080 else if (Opc == ISD::SRL)
1081 N0 = ZExtPromoteOperand(Op.getOperand(0), PVT);
1083 N0 = PromoteOperand(N0, PVT, Replace);
1087 AddToWorklist(N0.getNode());
1089 ReplaceLoadWithPromotedLoad(Op.getOperand(0).getNode(), N0.getNode());
1091 DEBUG(dbgs() << "\nPromoting ";
1092 Op.getNode()->dump(&DAG));
1094 return DAG.getNode(ISD::TRUNCATE, dl, VT,
1095 DAG.getNode(Opc, dl, PVT, N0, Op.getOperand(1)));
1100 SDValue DAGCombiner::PromoteExtend(SDValue Op) {
1101 if (!LegalOperations)
1104 EVT VT = Op.getValueType();
1105 if (VT.isVector() || !VT.isInteger())
1108 // If operation type is 'undesirable', e.g. i16 on x86, consider
1110 unsigned Opc = Op.getOpcode();
1111 if (TLI.isTypeDesirableForOp(Opc, VT))
1115 // Consult target whether it is a good idea to promote this operation and
1116 // what's the right type to promote it to.
1117 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
1118 assert(PVT != VT && "Don't know what type to promote to!");
1119 // fold (aext (aext x)) -> (aext x)
1120 // fold (aext (zext x)) -> (zext x)
1121 // fold (aext (sext x)) -> (sext x)
1122 DEBUG(dbgs() << "\nPromoting ";
1123 Op.getNode()->dump(&DAG));
1124 return DAG.getNode(Op.getOpcode(), SDLoc(Op), VT, Op.getOperand(0));
1129 bool DAGCombiner::PromoteLoad(SDValue Op) {
1130 if (!LegalOperations)
1133 EVT VT = Op.getValueType();
1134 if (VT.isVector() || !VT.isInteger())
1137 // If operation type is 'undesirable', e.g. i16 on x86, consider
1139 unsigned Opc = Op.getOpcode();
1140 if (TLI.isTypeDesirableForOp(Opc, VT))
1144 // Consult target whether it is a good idea to promote this operation and
1145 // what's the right type to promote it to.
1146 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
1147 assert(PVT != VT && "Don't know what type to promote to!");
1150 SDNode *N = Op.getNode();
1151 LoadSDNode *LD = cast<LoadSDNode>(N);
1152 EVT MemVT = LD->getMemoryVT();
1153 ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
1154 ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, PVT, MemVT) ? ISD::ZEXTLOAD
1156 : LD->getExtensionType();
1157 SDValue NewLD = DAG.getExtLoad(ExtType, dl, PVT,
1158 LD->getChain(), LD->getBasePtr(),
1159 MemVT, LD->getMemOperand());
1160 SDValue Result = DAG.getNode(ISD::TRUNCATE, dl, VT, NewLD);
1162 DEBUG(dbgs() << "\nPromoting ";
1165 Result.getNode()->dump(&DAG);
1167 WorklistRemover DeadNodes(*this);
1168 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result);
1169 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), NewLD.getValue(1));
1170 deleteAndRecombine(N);
1171 AddToWorklist(Result.getNode());
1177 /// \brief Recursively delete a node which has no uses and any operands for
1178 /// which it is the only use.
1180 /// Note that this both deletes the nodes and removes them from the worklist.
1181 /// It also adds any nodes who have had a user deleted to the worklist as they
1182 /// may now have only one use and subject to other combines.
1183 bool DAGCombiner::recursivelyDeleteUnusedNodes(SDNode *N) {
1184 if (!N->use_empty())
1187 SmallSetVector<SDNode *, 16> Nodes;
1190 N = Nodes.pop_back_val();
1194 if (N->use_empty()) {
1195 for (const SDValue &ChildN : N->op_values())
1196 Nodes.insert(ChildN.getNode());
1198 removeFromWorklist(N);
1203 } while (!Nodes.empty());
1207 //===----------------------------------------------------------------------===//
1208 // Main DAG Combiner implementation
1209 //===----------------------------------------------------------------------===//
1211 void DAGCombiner::Run(CombineLevel AtLevel) {
1212 // set the instance variables, so that the various visit routines may use it.
1214 LegalOperations = Level >= AfterLegalizeVectorOps;
1215 LegalTypes = Level >= AfterLegalizeTypes;
1217 // Add all the dag nodes to the worklist.
1218 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
1219 E = DAG.allnodes_end(); I != E; ++I)
1222 // Create a dummy node (which is not added to allnodes), that adds a reference
1223 // to the root node, preventing it from being deleted, and tracking any
1224 // changes of the root.
1225 HandleSDNode Dummy(DAG.getRoot());
1227 // while the worklist isn't empty, find a node and
1228 // try and combine it.
1229 while (!WorklistMap.empty()) {
1231 // The Worklist holds the SDNodes in order, but it may contain null entries.
1233 N = Worklist.pop_back_val();
1236 bool GoodWorklistEntry = WorklistMap.erase(N);
1237 (void)GoodWorklistEntry;
1238 assert(GoodWorklistEntry &&
1239 "Found a worklist entry without a corresponding map entry!");
1241 // If N has no uses, it is dead. Make sure to revisit all N's operands once
1242 // N is deleted from the DAG, since they too may now be dead or may have a
1243 // reduced number of uses, allowing other xforms.
1244 if (recursivelyDeleteUnusedNodes(N))
1247 WorklistRemover DeadNodes(*this);
1249 // If this combine is running after legalizing the DAG, re-legalize any
1250 // nodes pulled off the worklist.
1251 if (Level == AfterLegalizeDAG) {
1252 SmallSetVector<SDNode *, 16> UpdatedNodes;
1253 bool NIsValid = DAG.LegalizeOp(N, UpdatedNodes);
1255 for (SDNode *LN : UpdatedNodes) {
1257 AddUsersToWorklist(LN);
1263 DEBUG(dbgs() << "\nCombining: "; N->dump(&DAG));
1265 // Add any operands of the new node which have not yet been combined to the
1266 // worklist as well. Because the worklist uniques things already, this
1267 // won't repeatedly process the same operand.
1268 CombinedNodes.insert(N);
1269 for (const SDValue &ChildN : N->op_values())
1270 if (!CombinedNodes.count(ChildN.getNode()))
1271 AddToWorklist(ChildN.getNode());
1273 SDValue RV = combine(N);
1280 // If we get back the same node we passed in, rather than a new node or
1281 // zero, we know that the node must have defined multiple values and
1282 // CombineTo was used. Since CombineTo takes care of the worklist
1283 // mechanics for us, we have no work to do in this case.
1284 if (RV.getNode() == N)
1287 assert(N->getOpcode() != ISD::DELETED_NODE &&
1288 RV.getNode()->getOpcode() != ISD::DELETED_NODE &&
1289 "Node was deleted but visit returned new node!");
1291 DEBUG(dbgs() << " ... into: ";
1292 RV.getNode()->dump(&DAG));
1294 // Transfer debug value.
1295 DAG.TransferDbgValues(SDValue(N, 0), RV);
1296 if (N->getNumValues() == RV.getNode()->getNumValues())
1297 DAG.ReplaceAllUsesWith(N, RV.getNode());
1299 assert(N->getValueType(0) == RV.getValueType() &&
1300 N->getNumValues() == 1 && "Type mismatch");
1302 DAG.ReplaceAllUsesWith(N, &OpV);
1305 // Push the new node and any users onto the worklist
1306 AddToWorklist(RV.getNode());
1307 AddUsersToWorklist(RV.getNode());
1309 // Finally, if the node is now dead, remove it from the graph. The node
1310 // may not be dead if the replacement process recursively simplified to
1311 // something else needing this node. This will also take care of adding any
1312 // operands which have lost a user to the worklist.
1313 recursivelyDeleteUnusedNodes(N);
1316 // If the root changed (e.g. it was a dead load, update the root).
1317 DAG.setRoot(Dummy.getValue());
1318 DAG.RemoveDeadNodes();
1321 SDValue DAGCombiner::visit(SDNode *N) {
1322 switch (N->getOpcode()) {
1324 case ISD::TokenFactor: return visitTokenFactor(N);
1325 case ISD::MERGE_VALUES: return visitMERGE_VALUES(N);
1326 case ISD::ADD: return visitADD(N);
1327 case ISD::SUB: return visitSUB(N);
1328 case ISD::ADDC: return visitADDC(N);
1329 case ISD::SUBC: return visitSUBC(N);
1330 case ISD::ADDE: return visitADDE(N);
1331 case ISD::SUBE: return visitSUBE(N);
1332 case ISD::MUL: return visitMUL(N);
1333 case ISD::SDIV: return visitSDIV(N);
1334 case ISD::UDIV: return visitUDIV(N);
1335 case ISD::SREM: return visitSREM(N);
1336 case ISD::UREM: return visitUREM(N);
1337 case ISD::MULHU: return visitMULHU(N);
1338 case ISD::MULHS: return visitMULHS(N);
1339 case ISD::SMUL_LOHI: return visitSMUL_LOHI(N);
1340 case ISD::UMUL_LOHI: return visitUMUL_LOHI(N);
1341 case ISD::SMULO: return visitSMULO(N);
1342 case ISD::UMULO: return visitUMULO(N);
1343 case ISD::SDIVREM: return visitSDIVREM(N);
1344 case ISD::UDIVREM: return visitUDIVREM(N);
1345 case ISD::AND: return visitAND(N);
1346 case ISD::OR: return visitOR(N);
1347 case ISD::XOR: return visitXOR(N);
1348 case ISD::SHL: return visitSHL(N);
1349 case ISD::SRA: return visitSRA(N);
1350 case ISD::SRL: return visitSRL(N);
1352 case ISD::ROTL: return visitRotate(N);
1353 case ISD::BSWAP: return visitBSWAP(N);
1354 case ISD::CTLZ: return visitCTLZ(N);
1355 case ISD::CTLZ_ZERO_UNDEF: return visitCTLZ_ZERO_UNDEF(N);
1356 case ISD::CTTZ: return visitCTTZ(N);
1357 case ISD::CTTZ_ZERO_UNDEF: return visitCTTZ_ZERO_UNDEF(N);
1358 case ISD::CTPOP: return visitCTPOP(N);
1359 case ISD::SELECT: return visitSELECT(N);
1360 case ISD::VSELECT: return visitVSELECT(N);
1361 case ISD::SELECT_CC: return visitSELECT_CC(N);
1362 case ISD::SETCC: return visitSETCC(N);
1363 case ISD::SIGN_EXTEND: return visitSIGN_EXTEND(N);
1364 case ISD::ZERO_EXTEND: return visitZERO_EXTEND(N);
1365 case ISD::ANY_EXTEND: return visitANY_EXTEND(N);
1366 case ISD::SIGN_EXTEND_INREG: return visitSIGN_EXTEND_INREG(N);
1367 case ISD::SIGN_EXTEND_VECTOR_INREG: return visitSIGN_EXTEND_VECTOR_INREG(N);
1368 case ISD::TRUNCATE: return visitTRUNCATE(N);
1369 case ISD::BITCAST: return visitBITCAST(N);
1370 case ISD::BUILD_PAIR: return visitBUILD_PAIR(N);
1371 case ISD::FADD: return visitFADD(N);
1372 case ISD::FSUB: return visitFSUB(N);
1373 case ISD::FMUL: return visitFMUL(N);
1374 case ISD::FMA: return visitFMA(N);
1375 case ISD::FDIV: return visitFDIV(N);
1376 case ISD::FREM: return visitFREM(N);
1377 case ISD::FSQRT: return visitFSQRT(N);
1378 case ISD::FCOPYSIGN: return visitFCOPYSIGN(N);
1379 case ISD::SINT_TO_FP: return visitSINT_TO_FP(N);
1380 case ISD::UINT_TO_FP: return visitUINT_TO_FP(N);
1381 case ISD::FP_TO_SINT: return visitFP_TO_SINT(N);
1382 case ISD::FP_TO_UINT: return visitFP_TO_UINT(N);
1383 case ISD::FP_ROUND: return visitFP_ROUND(N);
1384 case ISD::FP_ROUND_INREG: return visitFP_ROUND_INREG(N);
1385 case ISD::FP_EXTEND: return visitFP_EXTEND(N);
1386 case ISD::FNEG: return visitFNEG(N);
1387 case ISD::FABS: return visitFABS(N);
1388 case ISD::FFLOOR: return visitFFLOOR(N);
1389 case ISD::FMINNUM: return visitFMINNUM(N);
1390 case ISD::FMAXNUM: return visitFMAXNUM(N);
1391 case ISD::FCEIL: return visitFCEIL(N);
1392 case ISD::FTRUNC: return visitFTRUNC(N);
1393 case ISD::BRCOND: return visitBRCOND(N);
1394 case ISD::BR_CC: return visitBR_CC(N);
1395 case ISD::LOAD: return visitLOAD(N);
1396 case ISD::STORE: return visitSTORE(N);
1397 case ISD::INSERT_VECTOR_ELT: return visitINSERT_VECTOR_ELT(N);
1398 case ISD::EXTRACT_VECTOR_ELT: return visitEXTRACT_VECTOR_ELT(N);
1399 case ISD::BUILD_VECTOR: return visitBUILD_VECTOR(N);
1400 case ISD::CONCAT_VECTORS: return visitCONCAT_VECTORS(N);
1401 case ISD::EXTRACT_SUBVECTOR: return visitEXTRACT_SUBVECTOR(N);
1402 case ISD::VECTOR_SHUFFLE: return visitVECTOR_SHUFFLE(N);
1403 case ISD::SCALAR_TO_VECTOR: return visitSCALAR_TO_VECTOR(N);
1404 case ISD::INSERT_SUBVECTOR: return visitINSERT_SUBVECTOR(N);
1405 case ISD::MGATHER: return visitMGATHER(N);
1406 case ISD::MLOAD: return visitMLOAD(N);
1407 case ISD::MSCATTER: return visitMSCATTER(N);
1408 case ISD::MSTORE: return visitMSTORE(N);
1409 case ISD::FP_TO_FP16: return visitFP_TO_FP16(N);
1414 SDValue DAGCombiner::combine(SDNode *N) {
1415 SDValue RV = visit(N);
1417 // If nothing happened, try a target-specific DAG combine.
1418 if (!RV.getNode()) {
1419 assert(N->getOpcode() != ISD::DELETED_NODE &&
1420 "Node was deleted but visit returned NULL!");
1422 if (N->getOpcode() >= ISD::BUILTIN_OP_END ||
1423 TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode())) {
1425 // Expose the DAG combiner to the target combiner impls.
1426 TargetLowering::DAGCombinerInfo
1427 DagCombineInfo(DAG, Level, false, this);
1429 RV = TLI.PerformDAGCombine(N, DagCombineInfo);
1433 // If nothing happened still, try promoting the operation.
1434 if (!RV.getNode()) {
1435 switch (N->getOpcode()) {
1443 RV = PromoteIntBinOp(SDValue(N, 0));
1448 RV = PromoteIntShiftOp(SDValue(N, 0));
1450 case ISD::SIGN_EXTEND:
1451 case ISD::ZERO_EXTEND:
1452 case ISD::ANY_EXTEND:
1453 RV = PromoteExtend(SDValue(N, 0));
1456 if (PromoteLoad(SDValue(N, 0)))
1462 // If N is a commutative binary node, try commuting it to enable more
1464 if (!RV.getNode() && SelectionDAG::isCommutativeBinOp(N->getOpcode()) &&
1465 N->getNumValues() == 1) {
1466 SDValue N0 = N->getOperand(0);
1467 SDValue N1 = N->getOperand(1);
1469 // Constant operands are canonicalized to RHS.
1470 if (isa<ConstantSDNode>(N0) || !isa<ConstantSDNode>(N1)) {
1471 SDValue Ops[] = {N1, N0};
1473 if (const auto *BinNode = dyn_cast<BinaryWithFlagsSDNode>(N)) {
1474 CSENode = DAG.getNodeIfExists(N->getOpcode(), N->getVTList(), Ops,
1477 CSENode = DAG.getNodeIfExists(N->getOpcode(), N->getVTList(), Ops);
1480 return SDValue(CSENode, 0);
1487 /// Given a node, return its input chain if it has one, otherwise return a null
1489 static SDValue getInputChainForNode(SDNode *N) {
1490 if (unsigned NumOps = N->getNumOperands()) {
1491 if (N->getOperand(0).getValueType() == MVT::Other)
1492 return N->getOperand(0);
1493 if (N->getOperand(NumOps-1).getValueType() == MVT::Other)
1494 return N->getOperand(NumOps-1);
1495 for (unsigned i = 1; i < NumOps-1; ++i)
1496 if (N->getOperand(i).getValueType() == MVT::Other)
1497 return N->getOperand(i);
1502 SDValue DAGCombiner::visitTokenFactor(SDNode *N) {
1503 // If N has two operands, where one has an input chain equal to the other,
1504 // the 'other' chain is redundant.
1505 if (N->getNumOperands() == 2) {
1506 if (getInputChainForNode(N->getOperand(0).getNode()) == N->getOperand(1))
1507 return N->getOperand(0);
1508 if (getInputChainForNode(N->getOperand(1).getNode()) == N->getOperand(0))
1509 return N->getOperand(1);
1512 SmallVector<SDNode *, 8> TFs; // List of token factors to visit.
1513 SmallVector<SDValue, 8> Ops; // Ops for replacing token factor.
1514 SmallPtrSet<SDNode*, 16> SeenOps;
1515 bool Changed = false; // If we should replace this token factor.
1517 // Start out with this token factor.
1520 // Iterate through token factors. The TFs grows when new token factors are
1522 for (unsigned i = 0; i < TFs.size(); ++i) {
1523 SDNode *TF = TFs[i];
1525 // Check each of the operands.
1526 for (const SDValue &Op : TF->op_values()) {
1528 switch (Op.getOpcode()) {
1529 case ISD::EntryToken:
1530 // Entry tokens don't need to be added to the list. They are
1535 case ISD::TokenFactor:
1536 if (Op.hasOneUse() &&
1537 std::find(TFs.begin(), TFs.end(), Op.getNode()) == TFs.end()) {
1538 // Queue up for processing.
1539 TFs.push_back(Op.getNode());
1540 // Clean up in case the token factor is removed.
1541 AddToWorklist(Op.getNode());
1548 // Only add if it isn't already in the list.
1549 if (SeenOps.insert(Op.getNode()).second)
1560 // If we've changed things around then replace token factor.
1563 // The entry token is the only possible outcome.
1564 Result = DAG.getEntryNode();
1566 // New and improved token factor.
1567 Result = DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other, Ops);
1570 // Add users to worklist if AA is enabled, since it may introduce
1571 // a lot of new chained token factors while removing memory deps.
1572 bool UseAA = CombinerAA.getNumOccurrences() > 0 ? CombinerAA
1573 : DAG.getSubtarget().useAA();
1574 return CombineTo(N, Result, UseAA /*add to worklist*/);
1580 /// MERGE_VALUES can always be eliminated.
1581 SDValue DAGCombiner::visitMERGE_VALUES(SDNode *N) {
1582 WorklistRemover DeadNodes(*this);
1583 // Replacing results may cause a different MERGE_VALUES to suddenly
1584 // be CSE'd with N, and carry its uses with it. Iterate until no
1585 // uses remain, to ensure that the node can be safely deleted.
1586 // First add the users of this node to the work list so that they
1587 // can be tried again once they have new operands.
1588 AddUsersToWorklist(N);
1590 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1591 DAG.ReplaceAllUsesOfValueWith(SDValue(N, i), N->getOperand(i));
1592 } while (!N->use_empty());
1593 deleteAndRecombine(N);
1594 return SDValue(N, 0); // Return N so it doesn't get rechecked!
1597 static bool isNullConstant(SDValue V) {
1598 ConstantSDNode *Const = dyn_cast<ConstantSDNode>(V);
1599 return Const != nullptr && Const->isNullValue();
1602 static bool isNullFPConstant(SDValue V) {
1603 ConstantFPSDNode *Const = dyn_cast<ConstantFPSDNode>(V);
1604 return Const != nullptr && Const->isZero() && !Const->isNegative();
1607 static bool isAllOnesConstant(SDValue V) {
1608 ConstantSDNode *Const = dyn_cast<ConstantSDNode>(V);
1609 return Const != nullptr && Const->isAllOnesValue();
1612 static bool isOneConstant(SDValue V) {
1613 ConstantSDNode *Const = dyn_cast<ConstantSDNode>(V);
1614 return Const != nullptr && Const->isOne();
1617 /// If \p N is a ContantSDNode with isOpaque() == false return it casted to a
1618 /// ContantSDNode pointer else nullptr.
1619 static ConstantSDNode *getAsNonOpaqueConstant(SDValue N) {
1620 ConstantSDNode *Const = dyn_cast<ConstantSDNode>(N);
1621 return Const != nullptr && !Const->isOpaque() ? Const : nullptr;
1624 SDValue DAGCombiner::visitADD(SDNode *N) {
1625 SDValue N0 = N->getOperand(0);
1626 SDValue N1 = N->getOperand(1);
1627 EVT VT = N0.getValueType();
1630 if (VT.isVector()) {
1631 if (SDValue FoldedVOp = SimplifyVBinOp(N))
1634 // fold (add x, 0) -> x, vector edition
1635 if (ISD::isBuildVectorAllZeros(N1.getNode()))
1637 if (ISD::isBuildVectorAllZeros(N0.getNode()))
1641 // fold (add x, undef) -> undef
1642 if (N0.getOpcode() == ISD::UNDEF)
1644 if (N1.getOpcode() == ISD::UNDEF)
1646 // fold (add c1, c2) -> c1+c2
1647 ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
1648 ConstantSDNode *N1C = getAsNonOpaqueConstant(N1);
1650 return DAG.FoldConstantArithmetic(ISD::ADD, SDLoc(N), VT, N0C, N1C);
1651 // canonicalize constant to RHS
1652 if (isConstantIntBuildVectorOrConstantInt(N0) &&
1653 !isConstantIntBuildVectorOrConstantInt(N1))
1654 return DAG.getNode(ISD::ADD, SDLoc(N), VT, N1, N0);
1655 // fold (add x, 0) -> x
1656 if (isNullConstant(N1))
1658 // fold (add Sym, c) -> Sym+c
1659 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1660 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA) && N1C &&
1661 GA->getOpcode() == ISD::GlobalAddress)
1662 return DAG.getGlobalAddress(GA->getGlobal(), SDLoc(N1C), VT,
1664 (uint64_t)N1C->getSExtValue());
1665 // fold ((c1-A)+c2) -> (c1+c2)-A
1666 if (N1C && N0.getOpcode() == ISD::SUB)
1667 if (ConstantSDNode *N0C = getAsNonOpaqueConstant(N0.getOperand(0))) {
1669 return DAG.getNode(ISD::SUB, DL, VT,
1670 DAG.getConstant(N1C->getAPIntValue()+
1671 N0C->getAPIntValue(), DL, VT),
1675 if (SDValue RADD = ReassociateOps(ISD::ADD, SDLoc(N), N0, N1))
1677 // fold ((0-A) + B) -> B-A
1678 if (N0.getOpcode() == ISD::SUB && isNullConstant(N0.getOperand(0)))
1679 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1, N0.getOperand(1));
1680 // fold (A + (0-B)) -> A-B
1681 if (N1.getOpcode() == ISD::SUB && isNullConstant(N1.getOperand(0)))
1682 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, N1.getOperand(1));
1683 // fold (A+(B-A)) -> B
1684 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(1))
1685 return N1.getOperand(0);
1686 // fold ((B-A)+A) -> B
1687 if (N0.getOpcode() == ISD::SUB && N1 == N0.getOperand(1))
1688 return N0.getOperand(0);
1689 // fold (A+(B-(A+C))) to (B-C)
1690 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1691 N0 == N1.getOperand(1).getOperand(0))
1692 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1.getOperand(0),
1693 N1.getOperand(1).getOperand(1));
1694 // fold (A+(B-(C+A))) to (B-C)
1695 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1696 N0 == N1.getOperand(1).getOperand(1))
1697 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1.getOperand(0),
1698 N1.getOperand(1).getOperand(0));
1699 // fold (A+((B-A)+or-C)) to (B+or-C)
1700 if ((N1.getOpcode() == ISD::SUB || N1.getOpcode() == ISD::ADD) &&
1701 N1.getOperand(0).getOpcode() == ISD::SUB &&
1702 N0 == N1.getOperand(0).getOperand(1))
1703 return DAG.getNode(N1.getOpcode(), SDLoc(N), VT,
1704 N1.getOperand(0).getOperand(0), N1.getOperand(1));
1706 // fold (A-B)+(C-D) to (A+C)-(B+D) when A or C is constant
1707 if (N0.getOpcode() == ISD::SUB && N1.getOpcode() == ISD::SUB) {
1708 SDValue N00 = N0.getOperand(0);
1709 SDValue N01 = N0.getOperand(1);
1710 SDValue N10 = N1.getOperand(0);
1711 SDValue N11 = N1.getOperand(1);
1713 if (isa<ConstantSDNode>(N00) || isa<ConstantSDNode>(N10))
1714 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1715 DAG.getNode(ISD::ADD, SDLoc(N0), VT, N00, N10),
1716 DAG.getNode(ISD::ADD, SDLoc(N1), VT, N01, N11));
1719 if (!VT.isVector() && SimplifyDemandedBits(SDValue(N, 0)))
1720 return SDValue(N, 0);
1722 // fold (a+b) -> (a|b) iff a and b share no bits.
1723 if (VT.isInteger() && !VT.isVector()) {
1724 APInt LHSZero, LHSOne;
1725 APInt RHSZero, RHSOne;
1726 DAG.computeKnownBits(N0, LHSZero, LHSOne);
1728 if (LHSZero.getBoolValue()) {
1729 DAG.computeKnownBits(N1, RHSZero, RHSOne);
1731 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1732 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1733 if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero){
1734 if (!LegalOperations || TLI.isOperationLegal(ISD::OR, VT))
1735 return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N1);
1740 // fold (add x, shl(0 - y, n)) -> sub(x, shl(y, n))
1741 if (N1.getOpcode() == ISD::SHL && N1.getOperand(0).getOpcode() == ISD::SUB &&
1742 isNullConstant(N1.getOperand(0).getOperand(0)))
1743 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N0,
1744 DAG.getNode(ISD::SHL, SDLoc(N), VT,
1745 N1.getOperand(0).getOperand(1),
1747 if (N0.getOpcode() == ISD::SHL && N0.getOperand(0).getOpcode() == ISD::SUB &&
1748 isNullConstant(N0.getOperand(0).getOperand(0)))
1749 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1,
1750 DAG.getNode(ISD::SHL, SDLoc(N), VT,
1751 N0.getOperand(0).getOperand(1),
1754 if (N1.getOpcode() == ISD::AND) {
1755 SDValue AndOp0 = N1.getOperand(0);
1756 unsigned NumSignBits = DAG.ComputeNumSignBits(AndOp0);
1757 unsigned DestBits = VT.getScalarType().getSizeInBits();
1759 // (add z, (and (sbbl x, x), 1)) -> (sub z, (sbbl x, x))
1760 // and similar xforms where the inner op is either ~0 or 0.
1761 if (NumSignBits == DestBits && isOneConstant(N1->getOperand(1))) {
1763 return DAG.getNode(ISD::SUB, DL, VT, N->getOperand(0), AndOp0);
1767 // add (sext i1), X -> sub X, (zext i1)
1768 if (N0.getOpcode() == ISD::SIGN_EXTEND &&
1769 N0.getOperand(0).getValueType() == MVT::i1 &&
1770 !TLI.isOperationLegal(ISD::SIGN_EXTEND, MVT::i1)) {
1772 SDValue ZExt = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0));
1773 return DAG.getNode(ISD::SUB, DL, VT, N1, ZExt);
1776 // add X, (sextinreg Y i1) -> sub X, (and Y 1)
1777 if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG) {
1778 VTSDNode *TN = cast<VTSDNode>(N1.getOperand(1));
1779 if (TN->getVT() == MVT::i1) {
1781 SDValue ZExt = DAG.getNode(ISD::AND, DL, VT, N1.getOperand(0),
1782 DAG.getConstant(1, DL, VT));
1783 return DAG.getNode(ISD::SUB, DL, VT, N0, ZExt);
1790 SDValue DAGCombiner::visitADDC(SDNode *N) {
1791 SDValue N0 = N->getOperand(0);
1792 SDValue N1 = N->getOperand(1);
1793 EVT VT = N0.getValueType();
1795 // If the flag result is dead, turn this into an ADD.
1796 if (!N->hasAnyUseOfValue(1))
1797 return CombineTo(N, DAG.getNode(ISD::ADD, SDLoc(N), VT, N0, N1),
1798 DAG.getNode(ISD::CARRY_FALSE,
1799 SDLoc(N), MVT::Glue));
1801 // canonicalize constant to RHS.
1802 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1803 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1805 return DAG.getNode(ISD::ADDC, SDLoc(N), N->getVTList(), N1, N0);
1807 // fold (addc x, 0) -> x + no carry out
1808 if (isNullConstant(N1))
1809 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE,
1810 SDLoc(N), MVT::Glue));
1812 // fold (addc a, b) -> (or a, b), CARRY_FALSE iff a and b share no bits.
1813 APInt LHSZero, LHSOne;
1814 APInt RHSZero, RHSOne;
1815 DAG.computeKnownBits(N0, LHSZero, LHSOne);
1817 if (LHSZero.getBoolValue()) {
1818 DAG.computeKnownBits(N1, RHSZero, RHSOne);
1820 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1821 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1822 if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero)
1823 return CombineTo(N, DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N1),
1824 DAG.getNode(ISD::CARRY_FALSE,
1825 SDLoc(N), MVT::Glue));
1831 SDValue DAGCombiner::visitADDE(SDNode *N) {
1832 SDValue N0 = N->getOperand(0);
1833 SDValue N1 = N->getOperand(1);
1834 SDValue CarryIn = N->getOperand(2);
1836 // canonicalize constant to RHS
1837 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1838 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1840 return DAG.getNode(ISD::ADDE, SDLoc(N), N->getVTList(),
1843 // fold (adde x, y, false) -> (addc x, y)
1844 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
1845 return DAG.getNode(ISD::ADDC, SDLoc(N), N->getVTList(), N0, N1);
1850 // Since it may not be valid to emit a fold to zero for vector initializers
1851 // check if we can before folding.
1852 static SDValue tryFoldToZero(SDLoc DL, const TargetLowering &TLI, EVT VT,
1854 bool LegalOperations, bool LegalTypes) {
1856 return DAG.getConstant(0, DL, VT);
1857 if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT))
1858 return DAG.getConstant(0, DL, VT);
1862 SDValue DAGCombiner::visitSUB(SDNode *N) {
1863 SDValue N0 = N->getOperand(0);
1864 SDValue N1 = N->getOperand(1);
1865 EVT VT = N0.getValueType();
1868 if (VT.isVector()) {
1869 if (SDValue FoldedVOp = SimplifyVBinOp(N))
1872 // fold (sub x, 0) -> x, vector edition
1873 if (ISD::isBuildVectorAllZeros(N1.getNode()))
1877 // fold (sub x, x) -> 0
1878 // FIXME: Refactor this and xor and other similar operations together.
1880 return tryFoldToZero(SDLoc(N), TLI, VT, DAG, LegalOperations, LegalTypes);
1881 // fold (sub c1, c2) -> c1-c2
1882 ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
1883 ConstantSDNode *N1C = getAsNonOpaqueConstant(N1);
1885 return DAG.FoldConstantArithmetic(ISD::SUB, SDLoc(N), VT, N0C, N1C);
1886 // fold (sub x, c) -> (add x, -c)
1889 return DAG.getNode(ISD::ADD, DL, VT, N0,
1890 DAG.getConstant(-N1C->getAPIntValue(), DL, VT));
1892 // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1)
1893 if (isAllOnesConstant(N0))
1894 return DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0);
1895 // fold A-(A-B) -> B
1896 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(0))
1897 return N1.getOperand(1);
1898 // fold (A+B)-A -> B
1899 if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1)
1900 return N0.getOperand(1);
1901 // fold (A+B)-B -> A
1902 if (N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1)
1903 return N0.getOperand(0);
1904 // fold C2-(A+C1) -> (C2-C1)-A
1905 ConstantSDNode *N1C1 = N1.getOpcode() != ISD::ADD ? nullptr :
1906 dyn_cast<ConstantSDNode>(N1.getOperand(1).getNode());
1907 if (N1.getOpcode() == ISD::ADD && N0C && N1C1) {
1909 SDValue NewC = DAG.getConstant(N0C->getAPIntValue() - N1C1->getAPIntValue(),
1911 return DAG.getNode(ISD::SUB, DL, VT, NewC,
1914 // fold ((A+(B+or-C))-B) -> A+or-C
1915 if (N0.getOpcode() == ISD::ADD &&
1916 (N0.getOperand(1).getOpcode() == ISD::SUB ||
1917 N0.getOperand(1).getOpcode() == ISD::ADD) &&
1918 N0.getOperand(1).getOperand(0) == N1)
1919 return DAG.getNode(N0.getOperand(1).getOpcode(), SDLoc(N), VT,
1920 N0.getOperand(0), N0.getOperand(1).getOperand(1));
1921 // fold ((A+(C+B))-B) -> A+C
1922 if (N0.getOpcode() == ISD::ADD &&
1923 N0.getOperand(1).getOpcode() == ISD::ADD &&
1924 N0.getOperand(1).getOperand(1) == N1)
1925 return DAG.getNode(ISD::ADD, SDLoc(N), VT,
1926 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1927 // fold ((A-(B-C))-C) -> A-B
1928 if (N0.getOpcode() == ISD::SUB &&
1929 N0.getOperand(1).getOpcode() == ISD::SUB &&
1930 N0.getOperand(1).getOperand(1) == N1)
1931 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1932 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1934 // If either operand of a sub is undef, the result is undef
1935 if (N0.getOpcode() == ISD::UNDEF)
1937 if (N1.getOpcode() == ISD::UNDEF)
1940 // If the relocation model supports it, consider symbol offsets.
1941 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1942 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA)) {
1943 // fold (sub Sym, c) -> Sym-c
1944 if (N1C && GA->getOpcode() == ISD::GlobalAddress)
1945 return DAG.getGlobalAddress(GA->getGlobal(), SDLoc(N1C), VT,
1947 (uint64_t)N1C->getSExtValue());
1948 // fold (sub Sym+c1, Sym+c2) -> c1-c2
1949 if (GlobalAddressSDNode *GB = dyn_cast<GlobalAddressSDNode>(N1))
1950 if (GA->getGlobal() == GB->getGlobal())
1951 return DAG.getConstant((uint64_t)GA->getOffset() - GB->getOffset(),
1955 // sub X, (sextinreg Y i1) -> add X, (and Y 1)
1956 if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG) {
1957 VTSDNode *TN = cast<VTSDNode>(N1.getOperand(1));
1958 if (TN->getVT() == MVT::i1) {
1960 SDValue ZExt = DAG.getNode(ISD::AND, DL, VT, N1.getOperand(0),
1961 DAG.getConstant(1, DL, VT));
1962 return DAG.getNode(ISD::ADD, DL, VT, N0, ZExt);
1969 SDValue DAGCombiner::visitSUBC(SDNode *N) {
1970 SDValue N0 = N->getOperand(0);
1971 SDValue N1 = N->getOperand(1);
1972 EVT VT = N0.getValueType();
1974 // If the flag result is dead, turn this into an SUB.
1975 if (!N->hasAnyUseOfValue(1))
1976 return CombineTo(N, DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, N1),
1977 DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1980 // fold (subc x, x) -> 0 + no borrow
1983 return CombineTo(N, DAG.getConstant(0, DL, VT),
1984 DAG.getNode(ISD::CARRY_FALSE, DL,
1988 // fold (subc x, 0) -> x + no borrow
1989 if (isNullConstant(N1))
1990 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1993 // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1) + no borrow
1994 if (isAllOnesConstant(N0))
1995 return CombineTo(N, DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0),
1996 DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
2002 SDValue DAGCombiner::visitSUBE(SDNode *N) {
2003 SDValue N0 = N->getOperand(0);
2004 SDValue N1 = N->getOperand(1);
2005 SDValue CarryIn = N->getOperand(2);
2007 // fold (sube x, y, false) -> (subc x, y)
2008 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
2009 return DAG.getNode(ISD::SUBC, SDLoc(N), N->getVTList(), N0, N1);
2014 SDValue DAGCombiner::visitMUL(SDNode *N) {
2015 SDValue N0 = N->getOperand(0);
2016 SDValue N1 = N->getOperand(1);
2017 EVT VT = N0.getValueType();
2019 // fold (mul x, undef) -> 0
2020 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2021 return DAG.getConstant(0, SDLoc(N), VT);
2023 bool N0IsConst = false;
2024 bool N1IsConst = false;
2025 bool N1IsOpaqueConst = false;
2026 bool N0IsOpaqueConst = false;
2027 APInt ConstValue0, ConstValue1;
2029 if (VT.isVector()) {
2030 if (SDValue FoldedVOp = SimplifyVBinOp(N))
2033 N0IsConst = isConstantSplatVector(N0.getNode(), ConstValue0);
2034 N1IsConst = isConstantSplatVector(N1.getNode(), ConstValue1);
2036 N0IsConst = isa<ConstantSDNode>(N0);
2038 ConstValue0 = cast<ConstantSDNode>(N0)->getAPIntValue();
2039 N0IsOpaqueConst = cast<ConstantSDNode>(N0)->isOpaque();
2041 N1IsConst = isa<ConstantSDNode>(N1);
2043 ConstValue1 = cast<ConstantSDNode>(N1)->getAPIntValue();
2044 N1IsOpaqueConst = cast<ConstantSDNode>(N1)->isOpaque();
2048 // fold (mul c1, c2) -> c1*c2
2049 if (N0IsConst && N1IsConst && !N0IsOpaqueConst && !N1IsOpaqueConst)
2050 return DAG.FoldConstantArithmetic(ISD::MUL, SDLoc(N), VT,
2051 N0.getNode(), N1.getNode());
2053 // canonicalize constant to RHS (vector doesn't have to splat)
2054 if (isConstantIntBuildVectorOrConstantInt(N0) &&
2055 !isConstantIntBuildVectorOrConstantInt(N1))
2056 return DAG.getNode(ISD::MUL, SDLoc(N), VT, N1, N0);
2057 // fold (mul x, 0) -> 0
2058 if (N1IsConst && ConstValue1 == 0)
2060 // We require a splat of the entire scalar bit width for non-contiguous
2063 ConstValue1.getBitWidth() == VT.getScalarType().getSizeInBits();
2064 // fold (mul x, 1) -> x
2065 if (N1IsConst && ConstValue1 == 1 && IsFullSplat)
2067 // fold (mul x, -1) -> 0-x
2068 if (N1IsConst && ConstValue1.isAllOnesValue()) {
2070 return DAG.getNode(ISD::SUB, DL, VT,
2071 DAG.getConstant(0, DL, VT), N0);
2073 // fold (mul x, (1 << c)) -> x << c
2074 if (N1IsConst && !N1IsOpaqueConst && ConstValue1.isPowerOf2() &&
2077 return DAG.getNode(ISD::SHL, DL, VT, N0,
2078 DAG.getConstant(ConstValue1.logBase2(), DL,
2079 getShiftAmountTy(N0.getValueType())));
2081 // fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c
2082 if (N1IsConst && !N1IsOpaqueConst && (-ConstValue1).isPowerOf2() &&
2084 unsigned Log2Val = (-ConstValue1).logBase2();
2086 // FIXME: If the input is something that is easily negated (e.g. a
2087 // single-use add), we should put the negate there.
2088 return DAG.getNode(ISD::SUB, DL, VT,
2089 DAG.getConstant(0, DL, VT),
2090 DAG.getNode(ISD::SHL, DL, VT, N0,
2091 DAG.getConstant(Log2Val, DL,
2092 getShiftAmountTy(N0.getValueType()))));
2096 // (mul (shl X, c1), c2) -> (mul X, c2 << c1)
2097 if (N1IsConst && N0.getOpcode() == ISD::SHL &&
2098 (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
2099 isa<ConstantSDNode>(N0.getOperand(1)))) {
2100 SDValue C3 = DAG.getNode(ISD::SHL, SDLoc(N), VT,
2101 N1, N0.getOperand(1));
2102 AddToWorklist(C3.getNode());
2103 return DAG.getNode(ISD::MUL, SDLoc(N), VT,
2104 N0.getOperand(0), C3);
2107 // Change (mul (shl X, C), Y) -> (shl (mul X, Y), C) when the shift has one
2110 SDValue Sh(nullptr,0), Y(nullptr,0);
2111 // Check for both (mul (shl X, C), Y) and (mul Y, (shl X, C)).
2112 if (N0.getOpcode() == ISD::SHL &&
2113 (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
2114 isa<ConstantSDNode>(N0.getOperand(1))) &&
2115 N0.getNode()->hasOneUse()) {
2117 } else if (N1.getOpcode() == ISD::SHL &&
2118 isa<ConstantSDNode>(N1.getOperand(1)) &&
2119 N1.getNode()->hasOneUse()) {
2124 SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT,
2125 Sh.getOperand(0), Y);
2126 return DAG.getNode(ISD::SHL, SDLoc(N), VT,
2127 Mul, Sh.getOperand(1));
2131 // fold (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2)
2132 if (N1IsConst && N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse() &&
2133 (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
2134 isa<ConstantSDNode>(N0.getOperand(1))))
2135 return DAG.getNode(ISD::ADD, SDLoc(N), VT,
2136 DAG.getNode(ISD::MUL, SDLoc(N0), VT,
2137 N0.getOperand(0), N1),
2138 DAG.getNode(ISD::MUL, SDLoc(N1), VT,
2139 N0.getOperand(1), N1));
2142 if (SDValue RMUL = ReassociateOps(ISD::MUL, SDLoc(N), N0, N1))
2148 SDValue DAGCombiner::visitSDIV(SDNode *N) {
2149 SDValue N0 = N->getOperand(0);
2150 SDValue N1 = N->getOperand(1);
2151 EVT VT = N->getValueType(0);
2155 if (SDValue FoldedVOp = SimplifyVBinOp(N))
2158 // fold (sdiv c1, c2) -> c1/c2
2159 ConstantSDNode *N0C = isConstOrConstSplat(N0);
2160 ConstantSDNode *N1C = isConstOrConstSplat(N1);
2161 if (N0C && N1C && !N0C->isOpaque() && !N1C->isOpaque())
2162 return DAG.FoldConstantArithmetic(ISD::SDIV, SDLoc(N), VT, N0C, N1C);
2163 // fold (sdiv X, 1) -> X
2164 if (N1C && N1C->isOne())
2166 // fold (sdiv X, -1) -> 0-X
2167 if (N1C && N1C->isAllOnesValue()) {
2169 return DAG.getNode(ISD::SUB, DL, VT,
2170 DAG.getConstant(0, DL, VT), N0);
2172 // If we know the sign bits of both operands are zero, strength reduce to a
2173 // udiv instead. Handles (X&15) /s 4 -> X&15 >> 2
2174 if (!VT.isVector()) {
2175 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
2176 return DAG.getNode(ISD::UDIV, SDLoc(N), N1.getValueType(),
2180 // fold (sdiv X, pow2) -> simple ops after legalize
2181 // FIXME: We check for the exact bit here because the generic lowering gives
2182 // better results in that case. The target-specific lowering should learn how
2183 // to handle exact sdivs efficiently.
2184 if (N1C && !N1C->isNullValue() && !N1C->isOpaque() &&
2185 !cast<BinaryWithFlagsSDNode>(N)->Flags.hasExact() &&
2186 (N1C->getAPIntValue().isPowerOf2() ||
2187 (-N1C->getAPIntValue()).isPowerOf2())) {
2188 // If dividing by powers of two is cheap, then don't perform the following
2190 if (TLI.isPow2SDivCheap())
2193 // Target-specific implementation of sdiv x, pow2.
2194 SDValue Res = BuildSDIVPow2(N);
2198 unsigned lg2 = N1C->getAPIntValue().countTrailingZeros();
2201 // Splat the sign bit into the register
2203 DAG.getNode(ISD::SRA, DL, VT, N0,
2204 DAG.getConstant(VT.getScalarSizeInBits() - 1, DL,
2205 getShiftAmountTy(N0.getValueType())));
2206 AddToWorklist(SGN.getNode());
2208 // Add (N0 < 0) ? abs2 - 1 : 0;
2210 DAG.getNode(ISD::SRL, DL, VT, SGN,
2211 DAG.getConstant(VT.getScalarSizeInBits() - lg2, DL,
2212 getShiftAmountTy(SGN.getValueType())));
2213 SDValue ADD = DAG.getNode(ISD::ADD, DL, VT, N0, SRL);
2214 AddToWorklist(SRL.getNode());
2215 AddToWorklist(ADD.getNode()); // Divide by pow2
2216 SDValue SRA = DAG.getNode(ISD::SRA, DL, VT, ADD,
2217 DAG.getConstant(lg2, DL,
2218 getShiftAmountTy(ADD.getValueType())));
2220 // If we're dividing by a positive value, we're done. Otherwise, we must
2221 // negate the result.
2222 if (N1C->getAPIntValue().isNonNegative())
2225 AddToWorklist(SRA.getNode());
2226 return DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT), SRA);
2229 // If integer divide is expensive and we satisfy the requirements, emit an
2230 // alternate sequence.
2231 if (N1C && !TLI.isIntDivCheap()) {
2232 SDValue Op = BuildSDIV(N);
2233 if (Op.getNode()) return Op;
2237 if (N0.getOpcode() == ISD::UNDEF)
2238 return DAG.getConstant(0, SDLoc(N), VT);
2239 // X / undef -> undef
2240 if (N1.getOpcode() == ISD::UNDEF)
2246 SDValue DAGCombiner::visitUDIV(SDNode *N) {
2247 SDValue N0 = N->getOperand(0);
2248 SDValue N1 = N->getOperand(1);
2249 EVT VT = N->getValueType(0);
2253 if (SDValue FoldedVOp = SimplifyVBinOp(N))
2256 // fold (udiv c1, c2) -> c1/c2
2257 ConstantSDNode *N0C = isConstOrConstSplat(N0);
2258 ConstantSDNode *N1C = isConstOrConstSplat(N1);
2260 if (SDValue Folded = DAG.FoldConstantArithmetic(ISD::UDIV, SDLoc(N), VT,
2263 // fold (udiv x, (1 << c)) -> x >>u c
2264 if (N1C && !N1C->isOpaque() && N1C->getAPIntValue().isPowerOf2()) {
2266 return DAG.getNode(ISD::SRL, DL, VT, N0,
2267 DAG.getConstant(N1C->getAPIntValue().logBase2(), DL,
2268 getShiftAmountTy(N0.getValueType())));
2270 // fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) iff c is power of 2
2271 if (N1.getOpcode() == ISD::SHL) {
2272 if (ConstantSDNode *SHC = getAsNonOpaqueConstant(N1.getOperand(0))) {
2273 if (SHC->getAPIntValue().isPowerOf2()) {
2274 EVT ADDVT = N1.getOperand(1).getValueType();
2276 SDValue Add = DAG.getNode(ISD::ADD, DL, ADDVT,
2278 DAG.getConstant(SHC->getAPIntValue()
2281 AddToWorklist(Add.getNode());
2282 return DAG.getNode(ISD::SRL, DL, VT, N0, Add);
2286 // fold (udiv x, c) -> alternate
2287 if (N1C && !TLI.isIntDivCheap()) {
2288 SDValue Op = BuildUDIV(N);
2289 if (Op.getNode()) return Op;
2293 if (N0.getOpcode() == ISD::UNDEF)
2294 return DAG.getConstant(0, SDLoc(N), VT);
2295 // X / undef -> undef
2296 if (N1.getOpcode() == ISD::UNDEF)
2302 SDValue DAGCombiner::visitSREM(SDNode *N) {
2303 SDValue N0 = N->getOperand(0);
2304 SDValue N1 = N->getOperand(1);
2305 EVT VT = N->getValueType(0);
2307 // fold (srem c1, c2) -> c1%c2
2308 ConstantSDNode *N0C = isConstOrConstSplat(N0);
2309 ConstantSDNode *N1C = isConstOrConstSplat(N1);
2311 if (SDValue Folded = DAG.FoldConstantArithmetic(ISD::SREM, SDLoc(N), VT,
2314 // If we know the sign bits of both operands are zero, strength reduce to a
2315 // urem instead. Handles (X & 0x0FFFFFFF) %s 16 -> X&15
2316 if (!VT.isVector()) {
2317 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
2318 return DAG.getNode(ISD::UREM, SDLoc(N), VT, N0, N1);
2321 // If X/C can be simplified by the division-by-constant logic, lower
2322 // X%C to the equivalent of X-X/C*C.
2323 if (N1C && !N1C->isNullValue()) {
2324 SDValue Div = DAG.getNode(ISD::SDIV, SDLoc(N), VT, N0, N1);
2325 AddToWorklist(Div.getNode());
2326 SDValue OptimizedDiv = combine(Div.getNode());
2327 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
2328 SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT,
2330 SDValue Sub = DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, Mul);
2331 AddToWorklist(Mul.getNode());
2337 if (N0.getOpcode() == ISD::UNDEF)
2338 return DAG.getConstant(0, SDLoc(N), VT);
2339 // X % undef -> undef
2340 if (N1.getOpcode() == ISD::UNDEF)
2346 SDValue DAGCombiner::visitUREM(SDNode *N) {
2347 SDValue N0 = N->getOperand(0);
2348 SDValue N1 = N->getOperand(1);
2349 EVT VT = N->getValueType(0);
2351 // fold (urem c1, c2) -> c1%c2
2352 ConstantSDNode *N0C = isConstOrConstSplat(N0);
2353 ConstantSDNode *N1C = isConstOrConstSplat(N1);
2355 if (SDValue Folded = DAG.FoldConstantArithmetic(ISD::UREM, SDLoc(N), VT,
2358 // fold (urem x, pow2) -> (and x, pow2-1)
2359 if (N1C && !N1C->isNullValue() && !N1C->isOpaque() &&
2360 N1C->getAPIntValue().isPowerOf2()) {
2362 return DAG.getNode(ISD::AND, DL, VT, N0,
2363 DAG.getConstant(N1C->getAPIntValue() - 1, DL, VT));
2365 // fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1))
2366 if (N1.getOpcode() == ISD::SHL) {
2367 if (ConstantSDNode *SHC = getAsNonOpaqueConstant(N1.getOperand(0))) {
2368 if (SHC->getAPIntValue().isPowerOf2()) {
2371 DAG.getNode(ISD::ADD, DL, VT, N1,
2372 DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()), DL,
2374 AddToWorklist(Add.getNode());
2375 return DAG.getNode(ISD::AND, DL, VT, N0, Add);
2380 // If X/C can be simplified by the division-by-constant logic, lower
2381 // X%C to the equivalent of X-X/C*C.
2382 if (N1C && !N1C->isNullValue()) {
2383 SDValue Div = DAG.getNode(ISD::UDIV, SDLoc(N), VT, N0, N1);
2384 AddToWorklist(Div.getNode());
2385 SDValue OptimizedDiv = combine(Div.getNode());
2386 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
2387 SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT,
2389 SDValue Sub = DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, Mul);
2390 AddToWorklist(Mul.getNode());
2396 if (N0.getOpcode() == ISD::UNDEF)
2397 return DAG.getConstant(0, SDLoc(N), VT);
2398 // X % undef -> undef
2399 if (N1.getOpcode() == ISD::UNDEF)
2405 SDValue DAGCombiner::visitMULHS(SDNode *N) {
2406 SDValue N0 = N->getOperand(0);
2407 SDValue N1 = N->getOperand(1);
2408 EVT VT = N->getValueType(0);
2411 // fold (mulhs x, 0) -> 0
2412 if (isNullConstant(N1))
2414 // fold (mulhs x, 1) -> (sra x, size(x)-1)
2415 if (isOneConstant(N1)) {
2417 return DAG.getNode(ISD::SRA, DL, N0.getValueType(), N0,
2418 DAG.getConstant(N0.getValueType().getSizeInBits() - 1,
2420 getShiftAmountTy(N0.getValueType())));
2422 // fold (mulhs x, undef) -> 0
2423 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2424 return DAG.getConstant(0, SDLoc(N), VT);
2426 // If the type twice as wide is legal, transform the mulhs to a wider multiply
2428 if (VT.isSimple() && !VT.isVector()) {
2429 MVT Simple = VT.getSimpleVT();
2430 unsigned SimpleSize = Simple.getSizeInBits();
2431 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2432 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2433 N0 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N0);
2434 N1 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N1);
2435 N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
2436 N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
2437 DAG.getConstant(SimpleSize, DL,
2438 getShiftAmountTy(N1.getValueType())));
2439 return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
2446 SDValue DAGCombiner::visitMULHU(SDNode *N) {
2447 SDValue N0 = N->getOperand(0);
2448 SDValue N1 = N->getOperand(1);
2449 EVT VT = N->getValueType(0);
2452 // fold (mulhu x, 0) -> 0
2453 if (isNullConstant(N1))
2455 // fold (mulhu x, 1) -> 0
2456 if (isOneConstant(N1))
2457 return DAG.getConstant(0, DL, N0.getValueType());
2458 // fold (mulhu x, undef) -> 0
2459 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2460 return DAG.getConstant(0, DL, VT);
2462 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2464 if (VT.isSimple() && !VT.isVector()) {
2465 MVT Simple = VT.getSimpleVT();
2466 unsigned SimpleSize = Simple.getSizeInBits();
2467 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2468 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2469 N0 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N0);
2470 N1 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N1);
2471 N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
2472 N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
2473 DAG.getConstant(SimpleSize, DL,
2474 getShiftAmountTy(N1.getValueType())));
2475 return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
2482 /// Perform optimizations common to nodes that compute two values. LoOp and HiOp
2483 /// give the opcodes for the two computations that are being performed. Return
2484 /// true if a simplification was made.
2485 SDValue DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
2487 // If the high half is not needed, just compute the low half.
2488 bool HiExists = N->hasAnyUseOfValue(1);
2490 (!LegalOperations ||
2491 TLI.isOperationLegalOrCustom(LoOp, N->getValueType(0)))) {
2492 SDValue Res = DAG.getNode(LoOp, SDLoc(N), N->getValueType(0), N->ops());
2493 return CombineTo(N, Res, Res);
2496 // If the low half is not needed, just compute the high half.
2497 bool LoExists = N->hasAnyUseOfValue(0);
2499 (!LegalOperations ||
2500 TLI.isOperationLegal(HiOp, N->getValueType(1)))) {
2501 SDValue Res = DAG.getNode(HiOp, SDLoc(N), N->getValueType(1), N->ops());
2502 return CombineTo(N, Res, Res);
2505 // If both halves are used, return as it is.
2506 if (LoExists && HiExists)
2509 // If the two computed results can be simplified separately, separate them.
2511 SDValue Lo = DAG.getNode(LoOp, SDLoc(N), N->getValueType(0), N->ops());
2512 AddToWorklist(Lo.getNode());
2513 SDValue LoOpt = combine(Lo.getNode());
2514 if (LoOpt.getNode() && LoOpt.getNode() != Lo.getNode() &&
2515 (!LegalOperations ||
2516 TLI.isOperationLegal(LoOpt.getOpcode(), LoOpt.getValueType())))
2517 return CombineTo(N, LoOpt, LoOpt);
2521 SDValue Hi = DAG.getNode(HiOp, SDLoc(N), N->getValueType(1), N->ops());
2522 AddToWorklist(Hi.getNode());
2523 SDValue HiOpt = combine(Hi.getNode());
2524 if (HiOpt.getNode() && HiOpt != Hi &&
2525 (!LegalOperations ||
2526 TLI.isOperationLegal(HiOpt.getOpcode(), HiOpt.getValueType())))
2527 return CombineTo(N, HiOpt, HiOpt);
2533 SDValue DAGCombiner::visitSMUL_LOHI(SDNode *N) {
2534 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHS);
2535 if (Res.getNode()) return Res;
2537 EVT VT = N->getValueType(0);
2540 // If the type is twice as wide is legal, transform the mulhu to a wider
2541 // multiply plus a shift.
2542 if (VT.isSimple() && !VT.isVector()) {
2543 MVT Simple = VT.getSimpleVT();
2544 unsigned SimpleSize = Simple.getSizeInBits();
2545 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2546 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2547 SDValue Lo = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(0));
2548 SDValue Hi = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(1));
2549 Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
2550 // Compute the high part as N1.
2551 Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
2552 DAG.getConstant(SimpleSize, DL,
2553 getShiftAmountTy(Lo.getValueType())));
2554 Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
2555 // Compute the low part as N0.
2556 Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
2557 return CombineTo(N, Lo, Hi);
2564 SDValue DAGCombiner::visitUMUL_LOHI(SDNode *N) {
2565 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHU);
2566 if (Res.getNode()) return Res;
2568 EVT VT = N->getValueType(0);
2571 // If the type is twice as wide is legal, transform the mulhu to a wider
2572 // multiply plus a shift.
2573 if (VT.isSimple() && !VT.isVector()) {
2574 MVT Simple = VT.getSimpleVT();
2575 unsigned SimpleSize = Simple.getSizeInBits();
2576 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2577 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2578 SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(0));
2579 SDValue Hi = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(1));
2580 Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
2581 // Compute the high part as N1.
2582 Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
2583 DAG.getConstant(SimpleSize, DL,
2584 getShiftAmountTy(Lo.getValueType())));
2585 Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
2586 // Compute the low part as N0.
2587 Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
2588 return CombineTo(N, Lo, Hi);
2595 SDValue DAGCombiner::visitSMULO(SDNode *N) {
2596 // (smulo x, 2) -> (saddo x, x)
2597 if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
2598 if (C2->getAPIntValue() == 2)
2599 return DAG.getNode(ISD::SADDO, SDLoc(N), N->getVTList(),
2600 N->getOperand(0), N->getOperand(0));
2605 SDValue DAGCombiner::visitUMULO(SDNode *N) {
2606 // (umulo x, 2) -> (uaddo x, x)
2607 if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
2608 if (C2->getAPIntValue() == 2)
2609 return DAG.getNode(ISD::UADDO, SDLoc(N), N->getVTList(),
2610 N->getOperand(0), N->getOperand(0));
2615 SDValue DAGCombiner::visitSDIVREM(SDNode *N) {
2616 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::SDIV, ISD::SREM);
2617 if (Res.getNode()) return Res;
2622 SDValue DAGCombiner::visitUDIVREM(SDNode *N) {
2623 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::UDIV, ISD::UREM);
2624 if (Res.getNode()) return Res;
2629 /// If this is a binary operator with two operands of the same opcode, try to
2631 SDValue DAGCombiner::SimplifyBinOpWithSameOpcodeHands(SDNode *N) {
2632 SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
2633 EVT VT = N0.getValueType();
2634 assert(N0.getOpcode() == N1.getOpcode() && "Bad input!");
2636 // Bail early if none of these transforms apply.
2637 if (N0.getNode()->getNumOperands() == 0) return SDValue();
2639 // For each of OP in AND/OR/XOR:
2640 // fold (OP (zext x), (zext y)) -> (zext (OP x, y))
2641 // fold (OP (sext x), (sext y)) -> (sext (OP x, y))
2642 // fold (OP (aext x), (aext y)) -> (aext (OP x, y))
2643 // fold (OP (bswap x), (bswap y)) -> (bswap (OP x, y))
2644 // fold (OP (trunc x), (trunc y)) -> (trunc (OP x, y)) (if trunc isn't free)
2646 // do not sink logical op inside of a vector extend, since it may combine
2648 EVT Op0VT = N0.getOperand(0).getValueType();
2649 if ((N0.getOpcode() == ISD::ZERO_EXTEND ||
2650 N0.getOpcode() == ISD::SIGN_EXTEND ||
2651 N0.getOpcode() == ISD::BSWAP ||
2652 // Avoid infinite looping with PromoteIntBinOp.
2653 (N0.getOpcode() == ISD::ANY_EXTEND &&
2654 (!LegalTypes || TLI.isTypeDesirableForOp(N->getOpcode(), Op0VT))) ||
2655 (N0.getOpcode() == ISD::TRUNCATE &&
2656 (!TLI.isZExtFree(VT, Op0VT) ||
2657 !TLI.isTruncateFree(Op0VT, VT)) &&
2658 TLI.isTypeLegal(Op0VT))) &&
2660 Op0VT == N1.getOperand(0).getValueType() &&
2661 (!LegalOperations || TLI.isOperationLegal(N->getOpcode(), Op0VT))) {
2662 SDValue ORNode = DAG.getNode(N->getOpcode(), SDLoc(N0),
2663 N0.getOperand(0).getValueType(),
2664 N0.getOperand(0), N1.getOperand(0));
2665 AddToWorklist(ORNode.getNode());
2666 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT, ORNode);
2669 // For each of OP in SHL/SRL/SRA/AND...
2670 // fold (and (OP x, z), (OP y, z)) -> (OP (and x, y), z)
2671 // fold (or (OP x, z), (OP y, z)) -> (OP (or x, y), z)
2672 // fold (xor (OP x, z), (OP y, z)) -> (OP (xor x, y), z)
2673 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL ||
2674 N0.getOpcode() == ISD::SRA || N0.getOpcode() == ISD::AND) &&
2675 N0.getOperand(1) == N1.getOperand(1)) {
2676 SDValue ORNode = DAG.getNode(N->getOpcode(), SDLoc(N0),
2677 N0.getOperand(0).getValueType(),
2678 N0.getOperand(0), N1.getOperand(0));
2679 AddToWorklist(ORNode.getNode());
2680 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
2681 ORNode, N0.getOperand(1));
2684 // Simplify xor/and/or (bitcast(A), bitcast(B)) -> bitcast(op (A,B))
2685 // Only perform this optimization after type legalization and before
2686 // LegalizeVectorOprs. LegalizeVectorOprs promotes vector operations by
2687 // adding bitcasts. For example (xor v4i32) is promoted to (v2i64), and
2688 // we don't want to undo this promotion.
2689 // We also handle SCALAR_TO_VECTOR because xor/or/and operations are cheaper
2691 if ((N0.getOpcode() == ISD::BITCAST ||
2692 N0.getOpcode() == ISD::SCALAR_TO_VECTOR) &&
2693 Level == AfterLegalizeTypes) {
2694 SDValue In0 = N0.getOperand(0);
2695 SDValue In1 = N1.getOperand(0);
2696 EVT In0Ty = In0.getValueType();
2697 EVT In1Ty = In1.getValueType();
2699 // If both incoming values are integers, and the original types are the
2701 if (In0Ty.isInteger() && In1Ty.isInteger() && In0Ty == In1Ty) {
2702 SDValue Op = DAG.getNode(N->getOpcode(), DL, In0Ty, In0, In1);
2703 SDValue BC = DAG.getNode(N0.getOpcode(), DL, VT, Op);
2704 AddToWorklist(Op.getNode());
2709 // Xor/and/or are indifferent to the swizzle operation (shuffle of one value).
2710 // Simplify xor/and/or (shuff(A), shuff(B)) -> shuff(op (A,B))
2711 // If both shuffles use the same mask, and both shuffle within a single
2712 // vector, then it is worthwhile to move the swizzle after the operation.
2713 // The type-legalizer generates this pattern when loading illegal
2714 // vector types from memory. In many cases this allows additional shuffle
2716 // There are other cases where moving the shuffle after the xor/and/or
2717 // is profitable even if shuffles don't perform a swizzle.
2718 // If both shuffles use the same mask, and both shuffles have the same first
2719 // or second operand, then it might still be profitable to move the shuffle
2720 // after the xor/and/or operation.
2721 if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG) {
2722 ShuffleVectorSDNode *SVN0 = cast<ShuffleVectorSDNode>(N0);
2723 ShuffleVectorSDNode *SVN1 = cast<ShuffleVectorSDNode>(N1);
2725 assert(N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType() &&
2726 "Inputs to shuffles are not the same type");
2728 // Check that both shuffles use the same mask. The masks are known to be of
2729 // the same length because the result vector type is the same.
2730 // Check also that shuffles have only one use to avoid introducing extra
2732 if (SVN0->hasOneUse() && SVN1->hasOneUse() &&
2733 SVN0->getMask().equals(SVN1->getMask())) {
2734 SDValue ShOp = N0->getOperand(1);
2736 // Don't try to fold this node if it requires introducing a
2737 // build vector of all zeros that might be illegal at this stage.
2738 if (N->getOpcode() == ISD::XOR && ShOp.getOpcode() != ISD::UNDEF) {
2740 ShOp = DAG.getConstant(0, SDLoc(N), VT);
2745 // (AND (shuf (A, C), shuf (B, C)) -> shuf (AND (A, B), C)
2746 // (OR (shuf (A, C), shuf (B, C)) -> shuf (OR (A, B), C)
2747 // (XOR (shuf (A, C), shuf (B, C)) -> shuf (XOR (A, B), V_0)
2748 if (N0.getOperand(1) == N1.getOperand(1) && ShOp.getNode()) {
2749 SDValue NewNode = DAG.getNode(N->getOpcode(), SDLoc(N), VT,
2750 N0->getOperand(0), N1->getOperand(0));
2751 AddToWorklist(NewNode.getNode());
2752 return DAG.getVectorShuffle(VT, SDLoc(N), NewNode, ShOp,
2753 &SVN0->getMask()[0]);
2756 // Don't try to fold this node if it requires introducing a
2757 // build vector of all zeros that might be illegal at this stage.
2758 ShOp = N0->getOperand(0);
2759 if (N->getOpcode() == ISD::XOR && ShOp.getOpcode() != ISD::UNDEF) {
2761 ShOp = DAG.getConstant(0, SDLoc(N), VT);
2766 // (AND (shuf (C, A), shuf (C, B)) -> shuf (C, AND (A, B))
2767 // (OR (shuf (C, A), shuf (C, B)) -> shuf (C, OR (A, B))
2768 // (XOR (shuf (C, A), shuf (C, B)) -> shuf (V_0, XOR (A, B))
2769 if (N0->getOperand(0) == N1->getOperand(0) && ShOp.getNode()) {
2770 SDValue NewNode = DAG.getNode(N->getOpcode(), SDLoc(N), VT,
2771 N0->getOperand(1), N1->getOperand(1));
2772 AddToWorklist(NewNode.getNode());
2773 return DAG.getVectorShuffle(VT, SDLoc(N), ShOp, NewNode,
2774 &SVN0->getMask()[0]);
2782 /// This contains all DAGCombine rules which reduce two values combined by
2783 /// an And operation to a single value. This makes them reusable in the context
2784 /// of visitSELECT(). Rules involving constants are not included as
2785 /// visitSELECT() already handles those cases.
2786 SDValue DAGCombiner::visitANDLike(SDValue N0, SDValue N1,
2787 SDNode *LocReference) {
2788 EVT VT = N1.getValueType();
2790 // fold (and x, undef) -> 0
2791 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2792 return DAG.getConstant(0, SDLoc(LocReference), VT);
2793 // fold (and (setcc x), (setcc y)) -> (setcc (and x, y))
2794 SDValue LL, LR, RL, RR, CC0, CC1;
2795 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
2796 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
2797 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
2799 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
2800 LL.getValueType().isInteger()) {
2801 // fold (and (seteq X, 0), (seteq Y, 0)) -> (seteq (or X, Y), 0)
2802 if (isNullConstant(LR) && Op1 == ISD::SETEQ) {
2803 SDValue ORNode = DAG.getNode(ISD::OR, SDLoc(N0),
2804 LR.getValueType(), LL, RL);
2805 AddToWorklist(ORNode.getNode());
2806 return DAG.getSetCC(SDLoc(LocReference), VT, ORNode, LR, Op1);
2808 if (isAllOnesConstant(LR)) {
2809 // fold (and (seteq X, -1), (seteq Y, -1)) -> (seteq (and X, Y), -1)
2810 if (Op1 == ISD::SETEQ) {
2811 SDValue ANDNode = DAG.getNode(ISD::AND, SDLoc(N0),
2812 LR.getValueType(), LL, RL);
2813 AddToWorklist(ANDNode.getNode());
2814 return DAG.getSetCC(SDLoc(LocReference), VT, ANDNode, LR, Op1);
2816 // fold (and (setgt X, -1), (setgt Y, -1)) -> (setgt (or X, Y), -1)
2817 if (Op1 == ISD::SETGT) {
2818 SDValue ORNode = DAG.getNode(ISD::OR, SDLoc(N0),
2819 LR.getValueType(), LL, RL);
2820 AddToWorklist(ORNode.getNode());
2821 return DAG.getSetCC(SDLoc(LocReference), VT, ORNode, LR, Op1);
2825 // Simplify (and (setne X, 0), (setne X, -1)) -> (setuge (add X, 1), 2)
2826 if (LL == RL && isa<ConstantSDNode>(LR) && isa<ConstantSDNode>(RR) &&
2827 Op0 == Op1 && LL.getValueType().isInteger() &&
2828 Op0 == ISD::SETNE && ((isNullConstant(LR) && isAllOnesConstant(RR)) ||
2829 (isAllOnesConstant(LR) && isNullConstant(RR)))) {
2831 SDValue ADDNode = DAG.getNode(ISD::ADD, DL, LL.getValueType(),
2832 LL, DAG.getConstant(1, DL,
2833 LL.getValueType()));
2834 AddToWorklist(ADDNode.getNode());
2835 return DAG.getSetCC(SDLoc(LocReference), VT, ADDNode,
2836 DAG.getConstant(2, DL, LL.getValueType()),
2839 // canonicalize equivalent to ll == rl
2840 if (LL == RR && LR == RL) {
2841 Op1 = ISD::getSetCCSwappedOperands(Op1);
2844 if (LL == RL && LR == RR) {
2845 bool isInteger = LL.getValueType().isInteger();
2846 ISD::CondCode Result = ISD::getSetCCAndOperation(Op0, Op1, isInteger);
2847 if (Result != ISD::SETCC_INVALID &&
2848 (!LegalOperations ||
2849 (TLI.isCondCodeLegal(Result, LL.getSimpleValueType()) &&
2850 TLI.isOperationLegal(ISD::SETCC,
2851 getSetCCResultType(N0.getSimpleValueType())))))
2852 return DAG.getSetCC(SDLoc(LocReference), N0.getValueType(),
2857 if (N0.getOpcode() == ISD::ADD && N1.getOpcode() == ISD::SRL &&
2858 VT.getSizeInBits() <= 64) {
2859 if (ConstantSDNode *ADDI = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
2860 APInt ADDC = ADDI->getAPIntValue();
2861 if (!TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
2862 // Look for (and (add x, c1), (lshr y, c2)). If C1 wasn't a legal
2863 // immediate for an add, but it is legal if its top c2 bits are set,
2864 // transform the ADD so the immediate doesn't need to be materialized
2866 if (ConstantSDNode *SRLI = dyn_cast<ConstantSDNode>(N1.getOperand(1))) {
2867 APInt Mask = APInt::getHighBitsSet(VT.getSizeInBits(),
2868 SRLI->getZExtValue());
2869 if (DAG.MaskedValueIsZero(N0.getOperand(1), Mask)) {
2871 if (TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
2874 DAG.getNode(ISD::ADD, DL, VT,
2875 N0.getOperand(0), DAG.getConstant(ADDC, DL, VT));
2876 CombineTo(N0.getNode(), NewAdd);
2877 // Return N so it doesn't get rechecked!
2878 return SDValue(LocReference, 0);
2889 SDValue DAGCombiner::visitAND(SDNode *N) {
2890 SDValue N0 = N->getOperand(0);
2891 SDValue N1 = N->getOperand(1);
2892 EVT VT = N1.getValueType();
2895 if (VT.isVector()) {
2896 if (SDValue FoldedVOp = SimplifyVBinOp(N))
2899 // fold (and x, 0) -> 0, vector edition
2900 if (ISD::isBuildVectorAllZeros(N0.getNode()))
2901 // do not return N0, because undef node may exist in N0
2902 return DAG.getConstant(
2903 APInt::getNullValue(
2904 N0.getValueType().getScalarType().getSizeInBits()),
2905 SDLoc(N), N0.getValueType());
2906 if (ISD::isBuildVectorAllZeros(N1.getNode()))
2907 // do not return N1, because undef node may exist in N1
2908 return DAG.getConstant(
2909 APInt::getNullValue(
2910 N1.getValueType().getScalarType().getSizeInBits()),
2911 SDLoc(N), N1.getValueType());
2913 // fold (and x, -1) -> x, vector edition
2914 if (ISD::isBuildVectorAllOnes(N0.getNode()))
2916 if (ISD::isBuildVectorAllOnes(N1.getNode()))
2920 // fold (and c1, c2) -> c1&c2
2921 ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
2922 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2923 if (N0C && N1C && !N1C->isOpaque())
2924 return DAG.FoldConstantArithmetic(ISD::AND, SDLoc(N), VT, N0C, N1C);
2925 // canonicalize constant to RHS
2926 if (isConstantIntBuildVectorOrConstantInt(N0) &&
2927 !isConstantIntBuildVectorOrConstantInt(N1))
2928 return DAG.getNode(ISD::AND, SDLoc(N), VT, N1, N0);
2929 // fold (and x, -1) -> x
2930 if (isAllOnesConstant(N1))
2932 // if (and x, c) is known to be zero, return 0
2933 unsigned BitWidth = VT.getScalarType().getSizeInBits();
2934 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
2935 APInt::getAllOnesValue(BitWidth)))
2936 return DAG.getConstant(0, SDLoc(N), VT);
2938 if (SDValue RAND = ReassociateOps(ISD::AND, SDLoc(N), N0, N1))
2940 // fold (and (or x, C), D) -> D if (C & D) == D
2941 if (N1C && N0.getOpcode() == ISD::OR)
2942 if (ConstantSDNode *ORI = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
2943 if ((ORI->getAPIntValue() & N1C->getAPIntValue()) == N1C->getAPIntValue())
2945 // fold (and (any_ext V), c) -> (zero_ext V) if 'and' only clears top bits.
2946 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
2947 SDValue N0Op0 = N0.getOperand(0);
2948 APInt Mask = ~N1C->getAPIntValue();
2949 Mask = Mask.trunc(N0Op0.getValueSizeInBits());
2950 if (DAG.MaskedValueIsZero(N0Op0, Mask)) {
2951 SDValue Zext = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N),
2952 N0.getValueType(), N0Op0);
2954 // Replace uses of the AND with uses of the Zero extend node.
2957 // We actually want to replace all uses of the any_extend with the
2958 // zero_extend, to avoid duplicating things. This will later cause this
2959 // AND to be folded.
2960 CombineTo(N0.getNode(), Zext);
2961 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2964 // similarly fold (and (X (load ([non_ext|any_ext|zero_ext] V))), c) ->
2965 // (X (load ([non_ext|zero_ext] V))) if 'and' only clears top bits which must
2966 // already be zero by virtue of the width of the base type of the load.
2968 // the 'X' node here can either be nothing or an extract_vector_elt to catch
2970 if ((N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
2971 N0.getOperand(0).getOpcode() == ISD::LOAD) ||
2972 N0.getOpcode() == ISD::LOAD) {
2973 LoadSDNode *Load = cast<LoadSDNode>( (N0.getOpcode() == ISD::LOAD) ?
2974 N0 : N0.getOperand(0) );
2976 // Get the constant (if applicable) the zero'th operand is being ANDed with.
2977 // This can be a pure constant or a vector splat, in which case we treat the
2978 // vector as a scalar and use the splat value.
2979 APInt Constant = APInt::getNullValue(1);
2980 if (const ConstantSDNode *C = dyn_cast<ConstantSDNode>(N1)) {
2981 Constant = C->getAPIntValue();
2982 } else if (BuildVectorSDNode *Vector = dyn_cast<BuildVectorSDNode>(N1)) {
2983 APInt SplatValue, SplatUndef;
2984 unsigned SplatBitSize;
2986 bool IsSplat = Vector->isConstantSplat(SplatValue, SplatUndef,
2987 SplatBitSize, HasAnyUndefs);
2989 // Undef bits can contribute to a possible optimisation if set, so
2991 SplatValue |= SplatUndef;
2993 // The splat value may be something like "0x00FFFFFF", which means 0 for
2994 // the first vector value and FF for the rest, repeating. We need a mask
2995 // that will apply equally to all members of the vector, so AND all the
2996 // lanes of the constant together.
2997 EVT VT = Vector->getValueType(0);
2998 unsigned BitWidth = VT.getVectorElementType().getSizeInBits();
3000 // If the splat value has been compressed to a bitlength lower
3001 // than the size of the vector lane, we need to re-expand it to
3003 if (BitWidth > SplatBitSize)
3004 for (SplatValue = SplatValue.zextOrTrunc(BitWidth);
3005 SplatBitSize < BitWidth;
3006 SplatBitSize = SplatBitSize * 2)
3007 SplatValue |= SplatValue.shl(SplatBitSize);
3009 // Make sure that variable 'Constant' is only set if 'SplatBitSize' is a
3010 // multiple of 'BitWidth'. Otherwise, we could propagate a wrong value.
3011 if (SplatBitSize % BitWidth == 0) {
3012 Constant = APInt::getAllOnesValue(BitWidth);
3013 for (unsigned i = 0, n = SplatBitSize/BitWidth; i < n; ++i)
3014 Constant &= SplatValue.lshr(i*BitWidth).zextOrTrunc(BitWidth);
3019 // If we want to change an EXTLOAD to a ZEXTLOAD, ensure a ZEXTLOAD is
3020 // actually legal and isn't going to get expanded, else this is a false
3022 bool CanZextLoadProfitably = TLI.isLoadExtLegal(ISD::ZEXTLOAD,
3023 Load->getValueType(0),
3024 Load->getMemoryVT());
3026 // Resize the constant to the same size as the original memory access before
3027 // extension. If it is still the AllOnesValue then this AND is completely
3030 Constant.zextOrTrunc(Load->getMemoryVT().getScalarType().getSizeInBits());
3033 switch (Load->getExtensionType()) {
3034 default: B = false; break;
3035 case ISD::EXTLOAD: B = CanZextLoadProfitably; break;
3037 case ISD::NON_EXTLOAD: B = true; break;
3040 if (B && Constant.isAllOnesValue()) {
3041 // If the load type was an EXTLOAD, convert to ZEXTLOAD in order to
3042 // preserve semantics once we get rid of the AND.
3043 SDValue NewLoad(Load, 0);
3044 if (Load->getExtensionType() == ISD::EXTLOAD) {
3045 NewLoad = DAG.getLoad(Load->getAddressingMode(), ISD::ZEXTLOAD,
3046 Load->getValueType(0), SDLoc(Load),
3047 Load->getChain(), Load->getBasePtr(),
3048 Load->getOffset(), Load->getMemoryVT(),
3049 Load->getMemOperand());
3050 // Replace uses of the EXTLOAD with the new ZEXTLOAD.
3051 if (Load->getNumValues() == 3) {
3052 // PRE/POST_INC loads have 3 values.
3053 SDValue To[] = { NewLoad.getValue(0), NewLoad.getValue(1),
3054 NewLoad.getValue(2) };
3055 CombineTo(Load, To, 3, true);
3057 CombineTo(Load, NewLoad.getValue(0), NewLoad.getValue(1));
3061 // Fold the AND away, taking care not to fold to the old load node if we
3063 CombineTo(N, (N0.getNode() == Load) ? NewLoad : N0);
3065 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3069 // fold (and (load x), 255) -> (zextload x, i8)
3070 // fold (and (extload x, i16), 255) -> (zextload x, i8)
3071 // fold (and (any_ext (extload x, i16)), 255) -> (zextload x, i8)
3072 if (N1C && (N0.getOpcode() == ISD::LOAD ||
3073 (N0.getOpcode() == ISD::ANY_EXTEND &&
3074 N0.getOperand(0).getOpcode() == ISD::LOAD))) {
3075 bool HasAnyExt = N0.getOpcode() == ISD::ANY_EXTEND;
3076 LoadSDNode *LN0 = HasAnyExt
3077 ? cast<LoadSDNode>(N0.getOperand(0))
3078 : cast<LoadSDNode>(N0);
3079 if (LN0->getExtensionType() != ISD::SEXTLOAD &&
3080 LN0->isUnindexed() && N0.hasOneUse() && SDValue(LN0, 0).hasOneUse()) {
3081 uint32_t ActiveBits = N1C->getAPIntValue().getActiveBits();
3082 if (ActiveBits > 0 && APIntOps::isMask(ActiveBits, N1C->getAPIntValue())){
3083 EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), ActiveBits);
3084 EVT LoadedVT = LN0->getMemoryVT();
3085 EVT LoadResultTy = HasAnyExt ? LN0->getValueType(0) : VT;
3087 if (ExtVT == LoadedVT &&
3088 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, LoadResultTy,
3092 DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), LoadResultTy,
3093 LN0->getChain(), LN0->getBasePtr(), ExtVT,
3094 LN0->getMemOperand());
3096 CombineTo(LN0, NewLoad, NewLoad.getValue(1));
3097 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3100 // Do not change the width of a volatile load.
3101 // Do not generate loads of non-round integer types since these can
3102 // be expensive (and would be wrong if the type is not byte sized).
3103 if (!LN0->isVolatile() && LoadedVT.bitsGT(ExtVT) && ExtVT.isRound() &&
3104 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, LoadResultTy,
3106 EVT PtrType = LN0->getOperand(1).getValueType();
3108 unsigned Alignment = LN0->getAlignment();
3109 SDValue NewPtr = LN0->getBasePtr();
3111 // For big endian targets, we need to add an offset to the pointer
3112 // to load the correct bytes. For little endian systems, we merely
3113 // need to read fewer bytes from the same pointer.
3114 if (TLI.isBigEndian()) {
3115 unsigned LVTStoreBytes = LoadedVT.getStoreSize();
3116 unsigned EVTStoreBytes = ExtVT.getStoreSize();
3117 unsigned PtrOff = LVTStoreBytes - EVTStoreBytes;
3119 NewPtr = DAG.getNode(ISD::ADD, DL, PtrType,
3120 NewPtr, DAG.getConstant(PtrOff, DL, PtrType));
3121 Alignment = MinAlign(Alignment, PtrOff);
3124 AddToWorklist(NewPtr.getNode());
3127 DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), LoadResultTy,
3128 LN0->getChain(), NewPtr,
3129 LN0->getPointerInfo(),
3130 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
3131 LN0->isInvariant(), Alignment, LN0->getAAInfo());
3133 CombineTo(LN0, Load, Load.getValue(1));
3134 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3140 if (SDValue Combined = visitANDLike(N0, N1, N))
3143 // Simplify: (and (op x...), (op y...)) -> (op (and x, y))
3144 if (N0.getOpcode() == N1.getOpcode()) {
3145 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
3146 if (Tmp.getNode()) return Tmp;
3149 // fold (and (sign_extend_inreg x, i16 to i32), 1) -> (and x, 1)
3150 // fold (and (sra)) -> (and (srl)) when possible.
3151 if (!VT.isVector() &&
3152 SimplifyDemandedBits(SDValue(N, 0)))
3153 return SDValue(N, 0);
3155 // fold (zext_inreg (extload x)) -> (zextload x)
3156 if (ISD::isEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode())) {
3157 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3158 EVT MemVT = LN0->getMemoryVT();
3159 // If we zero all the possible extended bits, then we can turn this into
3160 // a zextload if we are running before legalize or the operation is legal.
3161 unsigned BitWidth = N1.getValueType().getScalarType().getSizeInBits();
3162 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
3163 BitWidth - MemVT.getScalarType().getSizeInBits())) &&
3164 ((!LegalOperations && !LN0->isVolatile()) ||
3165 TLI.isLoadExtLegal(ISD::ZEXTLOAD, VT, MemVT))) {
3166 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N0), VT,
3167 LN0->getChain(), LN0->getBasePtr(),
3168 MemVT, LN0->getMemOperand());
3170 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
3171 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3174 // fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use
3175 if (ISD::isSEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
3177 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3178 EVT MemVT = LN0->getMemoryVT();
3179 // If we zero all the possible extended bits, then we can turn this into
3180 // a zextload if we are running before legalize or the operation is legal.
3181 unsigned BitWidth = N1.getValueType().getScalarType().getSizeInBits();
3182 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
3183 BitWidth - MemVT.getScalarType().getSizeInBits())) &&
3184 ((!LegalOperations && !LN0->isVolatile()) ||
3185 TLI.isLoadExtLegal(ISD::ZEXTLOAD, VT, MemVT))) {
3186 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N0), VT,
3187 LN0->getChain(), LN0->getBasePtr(),
3188 MemVT, LN0->getMemOperand());
3190 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
3191 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3194 // fold (and (or (srl N, 8), (shl N, 8)), 0xffff) -> (srl (bswap N), const)
3195 if (N1C && N1C->getAPIntValue() == 0xffff && N0.getOpcode() == ISD::OR) {
3196 SDValue BSwap = MatchBSwapHWordLow(N0.getNode(), N0.getOperand(0),
3197 N0.getOperand(1), false);
3198 if (BSwap.getNode())
3205 /// Match (a >> 8) | (a << 8) as (bswap a) >> 16.
3206 SDValue DAGCombiner::MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
3207 bool DemandHighBits) {
3208 if (!LegalOperations)
3211 EVT VT = N->getValueType(0);
3212 if (VT != MVT::i64 && VT != MVT::i32 && VT != MVT::i16)
3214 if (!TLI.isOperationLegal(ISD::BSWAP, VT))
3217 // Recognize (and (shl a, 8), 0xff), (and (srl a, 8), 0xff00)
3218 bool LookPassAnd0 = false;
3219 bool LookPassAnd1 = false;
3220 if (N0.getOpcode() == ISD::AND && N0.getOperand(0).getOpcode() == ISD::SRL)
3222 if (N1.getOpcode() == ISD::AND && N1.getOperand(0).getOpcode() == ISD::SHL)
3224 if (N0.getOpcode() == ISD::AND) {
3225 if (!N0.getNode()->hasOneUse())
3227 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3228 if (!N01C || N01C->getZExtValue() != 0xFF00)
3230 N0 = N0.getOperand(0);
3231 LookPassAnd0 = true;
3234 if (N1.getOpcode() == ISD::AND) {
3235 if (!N1.getNode()->hasOneUse())
3237 ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
3238 if (!N11C || N11C->getZExtValue() != 0xFF)
3240 N1 = N1.getOperand(0);
3241 LookPassAnd1 = true;
3244 if (N0.getOpcode() == ISD::SRL && N1.getOpcode() == ISD::SHL)
3246 if (N0.getOpcode() != ISD::SHL || N1.getOpcode() != ISD::SRL)
3248 if (!N0.getNode()->hasOneUse() ||
3249 !N1.getNode()->hasOneUse())
3252 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3253 ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
3256 if (N01C->getZExtValue() != 8 || N11C->getZExtValue() != 8)
3259 // Look for (shl (and a, 0xff), 8), (srl (and a, 0xff00), 8)
3260 SDValue N00 = N0->getOperand(0);
3261 if (!LookPassAnd0 && N00.getOpcode() == ISD::AND) {
3262 if (!N00.getNode()->hasOneUse())
3264 ConstantSDNode *N001C = dyn_cast<ConstantSDNode>(N00.getOperand(1));
3265 if (!N001C || N001C->getZExtValue() != 0xFF)
3267 N00 = N00.getOperand(0);
3268 LookPassAnd0 = true;
3271 SDValue N10 = N1->getOperand(0);
3272 if (!LookPassAnd1 && N10.getOpcode() == ISD::AND) {
3273 if (!N10.getNode()->hasOneUse())
3275 ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N10.getOperand(1));
3276 if (!N101C || N101C->getZExtValue() != 0xFF00)
3278 N10 = N10.getOperand(0);
3279 LookPassAnd1 = true;
3285 // Make sure everything beyond the low halfword gets set to zero since the SRL
3286 // 16 will clear the top bits.
3287 unsigned OpSizeInBits = VT.getSizeInBits();
3288 if (DemandHighBits && OpSizeInBits > 16) {
3289 // If the left-shift isn't masked out then the only way this is a bswap is
3290 // if all bits beyond the low 8 are 0. In that case the entire pattern
3291 // reduces to a left shift anyway: leave it for other parts of the combiner.
3295 // However, if the right shift isn't masked out then it might be because
3296 // it's not needed. See if we can spot that too.
3297 if (!LookPassAnd1 &&
3298 !DAG.MaskedValueIsZero(
3299 N10, APInt::getHighBitsSet(OpSizeInBits, OpSizeInBits - 16)))
3303 SDValue Res = DAG.getNode(ISD::BSWAP, SDLoc(N), VT, N00);
3304 if (OpSizeInBits > 16) {
3306 Res = DAG.getNode(ISD::SRL, DL, VT, Res,
3307 DAG.getConstant(OpSizeInBits - 16, DL,
3308 getShiftAmountTy(VT)));
3313 /// Return true if the specified node is an element that makes up a 32-bit
3314 /// packed halfword byteswap.
3315 /// ((x & 0x000000ff) << 8) |
3316 /// ((x & 0x0000ff00) >> 8) |
3317 /// ((x & 0x00ff0000) << 8) |
3318 /// ((x & 0xff000000) >> 8)
3319 static bool isBSwapHWordElement(SDValue N, MutableArrayRef<SDNode *> Parts) {
3320 if (!N.getNode()->hasOneUse())
3323 unsigned Opc = N.getOpcode();
3324 if (Opc != ISD::AND && Opc != ISD::SHL && Opc != ISD::SRL)
3327 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N.getOperand(1));
3332 switch (N1C->getZExtValue()) {
3335 case 0xFF: Num = 0; break;
3336 case 0xFF00: Num = 1; break;
3337 case 0xFF0000: Num = 2; break;
3338 case 0xFF000000: Num = 3; break;
3341 // Look for (x & 0xff) << 8 as well as ((x << 8) & 0xff00).
3342 SDValue N0 = N.getOperand(0);
3343 if (Opc == ISD::AND) {
3344 if (Num == 0 || Num == 2) {
3346 // (x >> 8) & 0xff0000
3347 if (N0.getOpcode() != ISD::SRL)
3349 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3350 if (!C || C->getZExtValue() != 8)
3353 // (x << 8) & 0xff00
3354 // (x << 8) & 0xff000000
3355 if (N0.getOpcode() != ISD::SHL)
3357 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3358 if (!C || C->getZExtValue() != 8)
3361 } else if (Opc == ISD::SHL) {
3363 // (x & 0xff0000) << 8
3364 if (Num != 0 && Num != 2)
3366 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
3367 if (!C || C->getZExtValue() != 8)
3369 } else { // Opc == ISD::SRL
3370 // (x & 0xff00) >> 8
3371 // (x & 0xff000000) >> 8
3372 if (Num != 1 && Num != 3)
3374 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
3375 if (!C || C->getZExtValue() != 8)
3382 Parts[Num] = N0.getOperand(0).getNode();
3386 /// Match a 32-bit packed halfword bswap. That is
3387 /// ((x & 0x000000ff) << 8) |
3388 /// ((x & 0x0000ff00) >> 8) |
3389 /// ((x & 0x00ff0000) << 8) |
3390 /// ((x & 0xff000000) >> 8)
3391 /// => (rotl (bswap x), 16)
3392 SDValue DAGCombiner::MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1) {
3393 if (!LegalOperations)
3396 EVT VT = N->getValueType(0);
3399 if (!TLI.isOperationLegal(ISD::BSWAP, VT))
3403 // (or (or (and), (and)), (or (and), (and)))
3404 // (or (or (or (and), (and)), (and)), (and))
3405 if (N0.getOpcode() != ISD::OR)
3407 SDValue N00 = N0.getOperand(0);
3408 SDValue N01 = N0.getOperand(1);
3409 SDNode *Parts[4] = {};
3411 if (N1.getOpcode() == ISD::OR &&
3412 N00.getNumOperands() == 2 && N01.getNumOperands() == 2) {
3413 // (or (or (and), (and)), (or (and), (and)))
3414 SDValue N000 = N00.getOperand(0);
3415 if (!isBSwapHWordElement(N000, Parts))
3418 SDValue N001 = N00.getOperand(1);
3419 if (!isBSwapHWordElement(N001, Parts))
3421 SDValue N010 = N01.getOperand(0);
3422 if (!isBSwapHWordElement(N010, Parts))
3424 SDValue N011 = N01.getOperand(1);
3425 if (!isBSwapHWordElement(N011, Parts))
3428 // (or (or (or (and), (and)), (and)), (and))
3429 if (!isBSwapHWordElement(N1, Parts))
3431 if (!isBSwapHWordElement(N01, Parts))
3433 if (N00.getOpcode() != ISD::OR)
3435 SDValue N000 = N00.getOperand(0);
3436 if (!isBSwapHWordElement(N000, Parts))
3438 SDValue N001 = N00.getOperand(1);
3439 if (!isBSwapHWordElement(N001, Parts))
3443 // Make sure the parts are all coming from the same node.
3444 if (Parts[0] != Parts[1] || Parts[0] != Parts[2] || Parts[0] != Parts[3])
3448 SDValue BSwap = DAG.getNode(ISD::BSWAP, DL, VT,
3449 SDValue(Parts[0], 0));
3451 // Result of the bswap should be rotated by 16. If it's not legal, then
3452 // do (x << 16) | (x >> 16).
3453 SDValue ShAmt = DAG.getConstant(16, DL, getShiftAmountTy(VT));
3454 if (TLI.isOperationLegalOrCustom(ISD::ROTL, VT))
3455 return DAG.getNode(ISD::ROTL, DL, VT, BSwap, ShAmt);
3456 if (TLI.isOperationLegalOrCustom(ISD::ROTR, VT))
3457 return DAG.getNode(ISD::ROTR, DL, VT, BSwap, ShAmt);
3458 return DAG.getNode(ISD::OR, DL, VT,
3459 DAG.getNode(ISD::SHL, DL, VT, BSwap, ShAmt),
3460 DAG.getNode(ISD::SRL, DL, VT, BSwap, ShAmt));
3463 /// This contains all DAGCombine rules which reduce two values combined by
3464 /// an Or operation to a single value \see visitANDLike().
3465 SDValue DAGCombiner::visitORLike(SDValue N0, SDValue N1, SDNode *LocReference) {
3466 EVT VT = N1.getValueType();
3467 // fold (or x, undef) -> -1
3468 if (!LegalOperations &&
3469 (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)) {
3470 EVT EltVT = VT.isVector() ? VT.getVectorElementType() : VT;
3471 return DAG.getConstant(APInt::getAllOnesValue(EltVT.getSizeInBits()),
3472 SDLoc(LocReference), VT);
3474 // fold (or (setcc x), (setcc y)) -> (setcc (or x, y))
3475 SDValue LL, LR, RL, RR, CC0, CC1;
3476 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
3477 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
3478 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
3480 if (LR == RR && Op0 == Op1 && LL.getValueType().isInteger()) {
3481 // fold (or (setne X, 0), (setne Y, 0)) -> (setne (or X, Y), 0)
3482 // fold (or (setlt X, 0), (setlt Y, 0)) -> (setne (or X, Y), 0)
3483 if (isNullConstant(LR) && (Op1 == ISD::SETNE || Op1 == ISD::SETLT)) {
3484 SDValue ORNode = DAG.getNode(ISD::OR, SDLoc(LR),
3485 LR.getValueType(), LL, RL);
3486 AddToWorklist(ORNode.getNode());
3487 return DAG.getSetCC(SDLoc(LocReference), VT, ORNode, LR, Op1);
3489 // fold (or (setne X, -1), (setne Y, -1)) -> (setne (and X, Y), -1)
3490 // fold (or (setgt X, -1), (setgt Y -1)) -> (setgt (and X, Y), -1)
3491 if (isAllOnesConstant(LR) && (Op1 == ISD::SETNE || Op1 == ISD::SETGT)) {
3492 SDValue ANDNode = DAG.getNode(ISD::AND, SDLoc(LR),
3493 LR.getValueType(), LL, RL);
3494 AddToWorklist(ANDNode.getNode());
3495 return DAG.getSetCC(SDLoc(LocReference), VT, ANDNode, LR, Op1);
3498 // canonicalize equivalent to ll == rl
3499 if (LL == RR && LR == RL) {
3500 Op1 = ISD::getSetCCSwappedOperands(Op1);
3503 if (LL == RL && LR == RR) {
3504 bool isInteger = LL.getValueType().isInteger();
3505 ISD::CondCode Result = ISD::getSetCCOrOperation(Op0, Op1, isInteger);
3506 if (Result != ISD::SETCC_INVALID &&
3507 (!LegalOperations ||
3508 (TLI.isCondCodeLegal(Result, LL.getSimpleValueType()) &&
3509 TLI.isOperationLegal(ISD::SETCC,
3510 getSetCCResultType(N0.getValueType())))))
3511 return DAG.getSetCC(SDLoc(LocReference), N0.getValueType(),
3516 // (or (and X, C1), (and Y, C2)) -> (and (or X, Y), C3) if possible.
3517 if (N0.getOpcode() == ISD::AND && N1.getOpcode() == ISD::AND &&
3518 // Don't increase # computations.
3519 (N0.getNode()->hasOneUse() || N1.getNode()->hasOneUse())) {
3520 // We can only do this xform if we know that bits from X that are set in C2
3521 // but not in C1 are already zero. Likewise for Y.
3522 if (const ConstantSDNode *N0O1C =
3523 getAsNonOpaqueConstant(N0.getOperand(1))) {
3524 if (const ConstantSDNode *N1O1C =
3525 getAsNonOpaqueConstant(N1.getOperand(1))) {
3526 // We can only do this xform if we know that bits from X that are set in
3527 // C2 but not in C1 are already zero. Likewise for Y.
3528 const APInt &LHSMask = N0O1C->getAPIntValue();
3529 const APInt &RHSMask = N1O1C->getAPIntValue();
3531 if (DAG.MaskedValueIsZero(N0.getOperand(0), RHSMask&~LHSMask) &&
3532 DAG.MaskedValueIsZero(N1.getOperand(0), LHSMask&~RHSMask)) {
3533 SDValue X = DAG.getNode(ISD::OR, SDLoc(N0), VT,
3534 N0.getOperand(0), N1.getOperand(0));
3535 SDLoc DL(LocReference);
3536 return DAG.getNode(ISD::AND, DL, VT, X,
3537 DAG.getConstant(LHSMask | RHSMask, DL, VT));
3543 // (or (and X, M), (and X, N)) -> (and X, (or M, N))
3544 if (N0.getOpcode() == ISD::AND &&
3545 N1.getOpcode() == ISD::AND &&
3546 N0.getOperand(0) == N1.getOperand(0) &&
3547 // Don't increase # computations.
3548 (N0.getNode()->hasOneUse() || N1.getNode()->hasOneUse())) {
3549 SDValue X = DAG.getNode(ISD::OR, SDLoc(N0), VT,
3550 N0.getOperand(1), N1.getOperand(1));
3551 return DAG.getNode(ISD::AND, SDLoc(LocReference), VT, N0.getOperand(0), X);
3557 SDValue DAGCombiner::visitOR(SDNode *N) {
3558 SDValue N0 = N->getOperand(0);
3559 SDValue N1 = N->getOperand(1);
3560 EVT VT = N1.getValueType();
3563 if (VT.isVector()) {
3564 if (SDValue FoldedVOp = SimplifyVBinOp(N))
3567 // fold (or x, 0) -> x, vector edition
3568 if (ISD::isBuildVectorAllZeros(N0.getNode()))
3570 if (ISD::isBuildVectorAllZeros(N1.getNode()))
3573 // fold (or x, -1) -> -1, vector edition
3574 if (ISD::isBuildVectorAllOnes(N0.getNode()))
3575 // do not return N0, because undef node may exist in N0
3576 return DAG.getConstant(
3577 APInt::getAllOnesValue(
3578 N0.getValueType().getScalarType().getSizeInBits()),
3579 SDLoc(N), N0.getValueType());
3580 if (ISD::isBuildVectorAllOnes(N1.getNode()))
3581 // do not return N1, because undef node may exist in N1
3582 return DAG.getConstant(
3583 APInt::getAllOnesValue(
3584 N1.getValueType().getScalarType().getSizeInBits()),
3585 SDLoc(N), N1.getValueType());
3587 // fold (or (shuf A, V_0, MA), (shuf B, V_0, MB)) -> (shuf A, B, Mask1)
3588 // fold (or (shuf A, V_0, MA), (shuf B, V_0, MB)) -> (shuf B, A, Mask2)
3589 // Do this only if the resulting shuffle is legal.
3590 if (isa<ShuffleVectorSDNode>(N0) &&
3591 isa<ShuffleVectorSDNode>(N1) &&
3592 // Avoid folding a node with illegal type.
3593 TLI.isTypeLegal(VT) &&
3594 N0->getOperand(1) == N1->getOperand(1) &&
3595 ISD::isBuildVectorAllZeros(N0.getOperand(1).getNode())) {
3596 bool CanFold = true;
3597 unsigned NumElts = VT.getVectorNumElements();
3598 const ShuffleVectorSDNode *SV0 = cast<ShuffleVectorSDNode>(N0);
3599 const ShuffleVectorSDNode *SV1 = cast<ShuffleVectorSDNode>(N1);
3600 // We construct two shuffle masks:
3601 // - Mask1 is a shuffle mask for a shuffle with N0 as the first operand
3602 // and N1 as the second operand.
3603 // - Mask2 is a shuffle mask for a shuffle with N1 as the first operand
3604 // and N0 as the second operand.
3605 // We do this because OR is commutable and therefore there might be
3606 // two ways to fold this node into a shuffle.
3607 SmallVector<int,4> Mask1;
3608 SmallVector<int,4> Mask2;
3610 for (unsigned i = 0; i != NumElts && CanFold; ++i) {
3611 int M0 = SV0->getMaskElt(i);
3612 int M1 = SV1->getMaskElt(i);
3614 // Both shuffle indexes are undef. Propagate Undef.
3615 if (M0 < 0 && M1 < 0) {
3616 Mask1.push_back(M0);
3617 Mask2.push_back(M0);
3621 if (M0 < 0 || M1 < 0 ||
3622 (M0 < (int)NumElts && M1 < (int)NumElts) ||
3623 (M0 >= (int)NumElts && M1 >= (int)NumElts)) {
3628 Mask1.push_back(M0 < (int)NumElts ? M0 : M1 + NumElts);
3629 Mask2.push_back(M1 < (int)NumElts ? M1 : M0 + NumElts);
3633 // Fold this sequence only if the resulting shuffle is 'legal'.
3634 if (TLI.isShuffleMaskLegal(Mask1, VT))
3635 return DAG.getVectorShuffle(VT, SDLoc(N), N0->getOperand(0),
3636 N1->getOperand(0), &Mask1[0]);
3637 if (TLI.isShuffleMaskLegal(Mask2, VT))
3638 return DAG.getVectorShuffle(VT, SDLoc(N), N1->getOperand(0),
3639 N0->getOperand(0), &Mask2[0]);
3644 // fold (or c1, c2) -> c1|c2
3645 ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
3646 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3647 if (N0C && N1C && !N1C->isOpaque())
3648 return DAG.FoldConstantArithmetic(ISD::OR, SDLoc(N), VT, N0C, N1C);
3649 // canonicalize constant to RHS
3650 if (isConstantIntBuildVectorOrConstantInt(N0) &&
3651 !isConstantIntBuildVectorOrConstantInt(N1))
3652 return DAG.getNode(ISD::OR, SDLoc(N), VT, N1, N0);
3653 // fold (or x, 0) -> x
3654 if (isNullConstant(N1))
3656 // fold (or x, -1) -> -1
3657 if (isAllOnesConstant(N1))
3659 // fold (or x, c) -> c iff (x & ~c) == 0
3660 if (N1C && DAG.MaskedValueIsZero(N0, ~N1C->getAPIntValue()))
3663 if (SDValue Combined = visitORLike(N0, N1, N))
3666 // Recognize halfword bswaps as (bswap + rotl 16) or (bswap + shl 16)
3667 SDValue BSwap = MatchBSwapHWord(N, N0, N1);
3668 if (BSwap.getNode())
3670 BSwap = MatchBSwapHWordLow(N, N0, N1);
3671 if (BSwap.getNode())
3675 if (SDValue ROR = ReassociateOps(ISD::OR, SDLoc(N), N0, N1))
3677 // Canonicalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2)
3678 // iff (c1 & c2) == 0.
3679 if (N1C && N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
3680 isa<ConstantSDNode>(N0.getOperand(1))) {
3681 ConstantSDNode *C1 = cast<ConstantSDNode>(N0.getOperand(1));
3682 if ((C1->getAPIntValue() & N1C->getAPIntValue()) != 0) {
3683 if (SDValue COR = DAG.FoldConstantArithmetic(ISD::OR, SDLoc(N1), VT,
3686 ISD::AND, SDLoc(N), VT,
3687 DAG.getNode(ISD::OR, SDLoc(N0), VT, N0.getOperand(0), N1), COR);
3691 // Simplify: (or (op x...), (op y...)) -> (op (or x, y))
3692 if (N0.getOpcode() == N1.getOpcode()) {
3693 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
3694 if (Tmp.getNode()) return Tmp;
3697 // See if this is some rotate idiom.
3698 if (SDNode *Rot = MatchRotate(N0, N1, SDLoc(N)))
3699 return SDValue(Rot, 0);
3701 // Simplify the operands using demanded-bits information.
3702 if (!VT.isVector() &&
3703 SimplifyDemandedBits(SDValue(N, 0)))
3704 return SDValue(N, 0);
3709 /// Match "(X shl/srl V1) & V2" where V2 may not be present.
3710 static bool MatchRotateHalf(SDValue Op, SDValue &Shift, SDValue &Mask) {
3711 if (Op.getOpcode() == ISD::AND) {
3712 if (isa<ConstantSDNode>(Op.getOperand(1))) {
3713 Mask = Op.getOperand(1);
3714 Op = Op.getOperand(0);
3720 if (Op.getOpcode() == ISD::SRL || Op.getOpcode() == ISD::SHL) {
3728 // Return true if we can prove that, whenever Neg and Pos are both in the
3729 // range [0, OpSize), Neg == (Pos == 0 ? 0 : OpSize - Pos). This means that
3730 // for two opposing shifts shift1 and shift2 and a value X with OpBits bits:
3732 // (or (shift1 X, Neg), (shift2 X, Pos))
3734 // reduces to a rotate in direction shift2 by Pos or (equivalently) a rotate
3735 // in direction shift1 by Neg. The range [0, OpSize) means that we only need
3736 // to consider shift amounts with defined behavior.
3737 static bool matchRotateSub(SDValue Pos, SDValue Neg, unsigned OpSize) {
3738 // If OpSize is a power of 2 then:
3740 // (a) (Pos == 0 ? 0 : OpSize - Pos) == (OpSize - Pos) & (OpSize - 1)
3741 // (b) Neg == Neg & (OpSize - 1) whenever Neg is in [0, OpSize).
3743 // So if OpSize is a power of 2 and Neg is (and Neg', OpSize-1), we check
3744 // for the stronger condition:
3746 // Neg & (OpSize - 1) == (OpSize - Pos) & (OpSize - 1) [A]
3748 // for all Neg and Pos. Since Neg & (OpSize - 1) == Neg' & (OpSize - 1)
3749 // we can just replace Neg with Neg' for the rest of the function.
3751 // In other cases we check for the even stronger condition:
3753 // Neg == OpSize - Pos [B]
3755 // for all Neg and Pos. Note that the (or ...) then invokes undefined
3756 // behavior if Pos == 0 (and consequently Neg == OpSize).
3758 // We could actually use [A] whenever OpSize is a power of 2, but the
3759 // only extra cases that it would match are those uninteresting ones
3760 // where Neg and Pos are never in range at the same time. E.g. for
3761 // OpSize == 32, using [A] would allow a Neg of the form (sub 64, Pos)
3762 // as well as (sub 32, Pos), but:
3764 // (or (shift1 X, (sub 64, Pos)), (shift2 X, Pos))
3766 // always invokes undefined behavior for 32-bit X.
3768 // Below, Mask == OpSize - 1 when using [A] and is all-ones otherwise.
3769 unsigned MaskLoBits = 0;
3770 if (Neg.getOpcode() == ISD::AND &&
3771 isPowerOf2_64(OpSize) &&
3772 Neg.getOperand(1).getOpcode() == ISD::Constant &&
3773 cast<ConstantSDNode>(Neg.getOperand(1))->getAPIntValue() == OpSize - 1) {
3774 Neg = Neg.getOperand(0);
3775 MaskLoBits = Log2_64(OpSize);
3778 // Check whether Neg has the form (sub NegC, NegOp1) for some NegC and NegOp1.
3779 if (Neg.getOpcode() != ISD::SUB)
3781 ConstantSDNode *NegC = dyn_cast<ConstantSDNode>(Neg.getOperand(0));
3784 SDValue NegOp1 = Neg.getOperand(1);
3786 // On the RHS of [A], if Pos is Pos' & (OpSize - 1), just replace Pos with
3787 // Pos'. The truncation is redundant for the purpose of the equality.
3789 Pos.getOpcode() == ISD::AND &&
3790 Pos.getOperand(1).getOpcode() == ISD::Constant &&
3791 cast<ConstantSDNode>(Pos.getOperand(1))->getAPIntValue() == OpSize - 1)
3792 Pos = Pos.getOperand(0);
3794 // The condition we need is now:
3796 // (NegC - NegOp1) & Mask == (OpSize - Pos) & Mask
3798 // If NegOp1 == Pos then we need:
3800 // OpSize & Mask == NegC & Mask
3802 // (because "x & Mask" is a truncation and distributes through subtraction).
3805 Width = NegC->getAPIntValue();
3806 // Check for cases where Pos has the form (add NegOp1, PosC) for some PosC.
3807 // Then the condition we want to prove becomes:
3809 // (NegC - NegOp1) & Mask == (OpSize - (NegOp1 + PosC)) & Mask
3811 // which, again because "x & Mask" is a truncation, becomes:
3813 // NegC & Mask == (OpSize - PosC) & Mask
3814 // OpSize & Mask == (NegC + PosC) & Mask
3815 else if (Pos.getOpcode() == ISD::ADD &&
3816 Pos.getOperand(0) == NegOp1 &&
3817 Pos.getOperand(1).getOpcode() == ISD::Constant)
3818 Width = (cast<ConstantSDNode>(Pos.getOperand(1))->getAPIntValue() +
3819 NegC->getAPIntValue());
3823 // Now we just need to check that OpSize & Mask == Width & Mask.
3825 // Opsize & Mask is 0 since Mask is Opsize - 1.
3826 return Width.getLoBits(MaskLoBits) == 0;
3827 return Width == OpSize;
3830 // A subroutine of MatchRotate used once we have found an OR of two opposite
3831 // shifts of Shifted. If Neg == <operand size> - Pos then the OR reduces
3832 // to both (PosOpcode Shifted, Pos) and (NegOpcode Shifted, Neg), with the
3833 // former being preferred if supported. InnerPos and InnerNeg are Pos and
3834 // Neg with outer conversions stripped away.
3835 SDNode *DAGCombiner::MatchRotatePosNeg(SDValue Shifted, SDValue Pos,
3836 SDValue Neg, SDValue InnerPos,
3837 SDValue InnerNeg, unsigned PosOpcode,
3838 unsigned NegOpcode, SDLoc DL) {
3839 // fold (or (shl x, (*ext y)),
3840 // (srl x, (*ext (sub 32, y)))) ->
3841 // (rotl x, y) or (rotr x, (sub 32, y))
3843 // fold (or (shl x, (*ext (sub 32, y))),
3844 // (srl x, (*ext y))) ->
3845 // (rotr x, y) or (rotl x, (sub 32, y))
3846 EVT VT = Shifted.getValueType();
3847 if (matchRotateSub(InnerPos, InnerNeg, VT.getSizeInBits())) {
3848 bool HasPos = TLI.isOperationLegalOrCustom(PosOpcode, VT);
3849 return DAG.getNode(HasPos ? PosOpcode : NegOpcode, DL, VT, Shifted,
3850 HasPos ? Pos : Neg).getNode();
3856 // MatchRotate - Handle an 'or' of two operands. If this is one of the many
3857 // idioms for rotate, and if the target supports rotation instructions, generate
3859 SDNode *DAGCombiner::MatchRotate(SDValue LHS, SDValue RHS, SDLoc DL) {
3860 // Must be a legal type. Expanded 'n promoted things won't work with rotates.
3861 EVT VT = LHS.getValueType();
3862 if (!TLI.isTypeLegal(VT)) return nullptr;
3864 // The target must have at least one rotate flavor.
3865 bool HasROTL = TLI.isOperationLegalOrCustom(ISD::ROTL, VT);
3866 bool HasROTR = TLI.isOperationLegalOrCustom(ISD::ROTR, VT);
3867 if (!HasROTL && !HasROTR) return nullptr;
3869 // Match "(X shl/srl V1) & V2" where V2 may not be present.
3870 SDValue LHSShift; // The shift.
3871 SDValue LHSMask; // AND value if any.
3872 if (!MatchRotateHalf(LHS, LHSShift, LHSMask))
3873 return nullptr; // Not part of a rotate.
3875 SDValue RHSShift; // The shift.
3876 SDValue RHSMask; // AND value if any.
3877 if (!MatchRotateHalf(RHS, RHSShift, RHSMask))
3878 return nullptr; // Not part of a rotate.
3880 if (LHSShift.getOperand(0) != RHSShift.getOperand(0))
3881 return nullptr; // Not shifting the same value.
3883 if (LHSShift.getOpcode() == RHSShift.getOpcode())
3884 return nullptr; // Shifts must disagree.
3886 // Canonicalize shl to left side in a shl/srl pair.
3887 if (RHSShift.getOpcode() == ISD::SHL) {
3888 std::swap(LHS, RHS);
3889 std::swap(LHSShift, RHSShift);
3890 std::swap(LHSMask , RHSMask );
3893 unsigned OpSizeInBits = VT.getSizeInBits();
3894 SDValue LHSShiftArg = LHSShift.getOperand(0);
3895 SDValue LHSShiftAmt = LHSShift.getOperand(1);
3896 SDValue RHSShiftArg = RHSShift.getOperand(0);
3897 SDValue RHSShiftAmt = RHSShift.getOperand(1);
3899 // fold (or (shl x, C1), (srl x, C2)) -> (rotl x, C1)
3900 // fold (or (shl x, C1), (srl x, C2)) -> (rotr x, C2)
3901 if (LHSShiftAmt.getOpcode() == ISD::Constant &&
3902 RHSShiftAmt.getOpcode() == ISD::Constant) {
3903 uint64_t LShVal = cast<ConstantSDNode>(LHSShiftAmt)->getZExtValue();
3904 uint64_t RShVal = cast<ConstantSDNode>(RHSShiftAmt)->getZExtValue();
3905 if ((LShVal + RShVal) != OpSizeInBits)
3908 SDValue Rot = DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT,
3909 LHSShiftArg, HasROTL ? LHSShiftAmt : RHSShiftAmt);
3911 // If there is an AND of either shifted operand, apply it to the result.
3912 if (LHSMask.getNode() || RHSMask.getNode()) {
3913 APInt Mask = APInt::getAllOnesValue(OpSizeInBits);
3915 if (LHSMask.getNode()) {
3916 APInt RHSBits = APInt::getLowBitsSet(OpSizeInBits, LShVal);
3917 Mask &= cast<ConstantSDNode>(LHSMask)->getAPIntValue() | RHSBits;
3919 if (RHSMask.getNode()) {
3920 APInt LHSBits = APInt::getHighBitsSet(OpSizeInBits, RShVal);
3921 Mask &= cast<ConstantSDNode>(RHSMask)->getAPIntValue() | LHSBits;
3924 Rot = DAG.getNode(ISD::AND, DL, VT, Rot, DAG.getConstant(Mask, DL, VT));
3927 return Rot.getNode();
3930 // If there is a mask here, and we have a variable shift, we can't be sure
3931 // that we're masking out the right stuff.
3932 if (LHSMask.getNode() || RHSMask.getNode())
3935 // If the shift amount is sign/zext/any-extended just peel it off.
3936 SDValue LExtOp0 = LHSShiftAmt;
3937 SDValue RExtOp0 = RHSShiftAmt;
3938 if ((LHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
3939 LHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
3940 LHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
3941 LHSShiftAmt.getOpcode() == ISD::TRUNCATE) &&
3942 (RHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
3943 RHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
3944 RHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
3945 RHSShiftAmt.getOpcode() == ISD::TRUNCATE)) {
3946 LExtOp0 = LHSShiftAmt.getOperand(0);
3947 RExtOp0 = RHSShiftAmt.getOperand(0);
3950 SDNode *TryL = MatchRotatePosNeg(LHSShiftArg, LHSShiftAmt, RHSShiftAmt,
3951 LExtOp0, RExtOp0, ISD::ROTL, ISD::ROTR, DL);
3955 SDNode *TryR = MatchRotatePosNeg(RHSShiftArg, RHSShiftAmt, LHSShiftAmt,
3956 RExtOp0, LExtOp0, ISD::ROTR, ISD::ROTL, DL);
3963 SDValue DAGCombiner::visitXOR(SDNode *N) {
3964 SDValue N0 = N->getOperand(0);
3965 SDValue N1 = N->getOperand(1);
3966 EVT VT = N0.getValueType();
3969 if (VT.isVector()) {
3970 if (SDValue FoldedVOp = SimplifyVBinOp(N))
3973 // fold (xor x, 0) -> x, vector edition
3974 if (ISD::isBuildVectorAllZeros(N0.getNode()))
3976 if (ISD::isBuildVectorAllZeros(N1.getNode()))
3980 // fold (xor undef, undef) -> 0. This is a common idiom (misuse).
3981 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
3982 return DAG.getConstant(0, SDLoc(N), VT);
3983 // fold (xor x, undef) -> undef
3984 if (N0.getOpcode() == ISD::UNDEF)
3986 if (N1.getOpcode() == ISD::UNDEF)
3988 // fold (xor c1, c2) -> c1^c2
3989 ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
3990 ConstantSDNode *N1C = getAsNonOpaqueConstant(N1);
3992 return DAG.FoldConstantArithmetic(ISD::XOR, SDLoc(N), VT, N0C, N1C);
3993 // canonicalize constant to RHS
3994 if (isConstantIntBuildVectorOrConstantInt(N0) &&
3995 !isConstantIntBuildVectorOrConstantInt(N1))
3996 return DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0);
3997 // fold (xor x, 0) -> x
3998 if (isNullConstant(N1))
4001 if (SDValue RXOR = ReassociateOps(ISD::XOR, SDLoc(N), N0, N1))
4004 // fold !(x cc y) -> (x !cc y)
4005 SDValue LHS, RHS, CC;
4006 if (TLI.isConstTrueVal(N1.getNode()) && isSetCCEquivalent(N0, LHS, RHS, CC)) {
4007 bool isInt = LHS.getValueType().isInteger();
4008 ISD::CondCode NotCC = ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
4011 if (!LegalOperations ||
4012 TLI.isCondCodeLegal(NotCC, LHS.getSimpleValueType())) {
4013 switch (N0.getOpcode()) {
4015 llvm_unreachable("Unhandled SetCC Equivalent!");
4017 return DAG.getSetCC(SDLoc(N), VT, LHS, RHS, NotCC);
4018 case ISD::SELECT_CC:
4019 return DAG.getSelectCC(SDLoc(N), LHS, RHS, N0.getOperand(2),
4020 N0.getOperand(3), NotCC);
4025 // fold (not (zext (setcc x, y))) -> (zext (not (setcc x, y)))
4026 if (isOneConstant(N1) && N0.getOpcode() == ISD::ZERO_EXTEND &&
4027 N0.getNode()->hasOneUse() &&
4028 isSetCCEquivalent(N0.getOperand(0), LHS, RHS, CC)){
4029 SDValue V = N0.getOperand(0);
4031 V = DAG.getNode(ISD::XOR, DL, V.getValueType(), V,
4032 DAG.getConstant(1, DL, V.getValueType()));
4033 AddToWorklist(V.getNode());
4034 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, V);
4037 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are setcc
4038 if (isOneConstant(N1) && VT == MVT::i1 &&
4039 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
4040 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
4041 if (isOneUseSetCC(RHS) || isOneUseSetCC(LHS)) {
4042 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
4043 LHS = DAG.getNode(ISD::XOR, SDLoc(LHS), VT, LHS, N1); // LHS = ~LHS
4044 RHS = DAG.getNode(ISD::XOR, SDLoc(RHS), VT, RHS, N1); // RHS = ~RHS
4045 AddToWorklist(LHS.getNode()); AddToWorklist(RHS.getNode());
4046 return DAG.getNode(NewOpcode, SDLoc(N), VT, LHS, RHS);
4049 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are constants
4050 if (isAllOnesConstant(N1) &&
4051 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
4052 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
4053 if (isa<ConstantSDNode>(RHS) || isa<ConstantSDNode>(LHS)) {
4054 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
4055 LHS = DAG.getNode(ISD::XOR, SDLoc(LHS), VT, LHS, N1); // LHS = ~LHS
4056 RHS = DAG.getNode(ISD::XOR, SDLoc(RHS), VT, RHS, N1); // RHS = ~RHS
4057 AddToWorklist(LHS.getNode()); AddToWorklist(RHS.getNode());
4058 return DAG.getNode(NewOpcode, SDLoc(N), VT, LHS, RHS);
4061 // fold (xor (and x, y), y) -> (and (not x), y)
4062 if (N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
4063 N0->getOperand(1) == N1) {
4064 SDValue X = N0->getOperand(0);
4065 SDValue NotX = DAG.getNOT(SDLoc(X), X, VT);
4066 AddToWorklist(NotX.getNode());
4067 return DAG.getNode(ISD::AND, SDLoc(N), VT, NotX, N1);
4069 // fold (xor (xor x, c1), c2) -> (xor x, (xor c1, c2))
4070 if (N1C && N0.getOpcode() == ISD::XOR) {
4071 if (const ConstantSDNode *N00C = getAsNonOpaqueConstant(N0.getOperand(0))) {
4073 return DAG.getNode(ISD::XOR, DL, VT, N0.getOperand(1),
4074 DAG.getConstant(N1C->getAPIntValue() ^
4075 N00C->getAPIntValue(), DL, VT));
4077 if (const ConstantSDNode *N01C = getAsNonOpaqueConstant(N0.getOperand(1))) {
4079 return DAG.getNode(ISD::XOR, DL, VT, N0.getOperand(0),
4080 DAG.getConstant(N1C->getAPIntValue() ^
4081 N01C->getAPIntValue(), DL, VT));
4084 // fold (xor x, x) -> 0
4086 return tryFoldToZero(SDLoc(N), TLI, VT, DAG, LegalOperations, LegalTypes);
4088 // fold (xor (shl 1, x), -1) -> (rotl ~1, x)
4089 // Here is a concrete example of this equivalence:
4091 // i16 shl == 1 << 14 == 16384 == 0b0100000000000000
4092 // i16 xor == ~(1 << 14) == 49151 == 0b1011111111111111
4096 // i16 ~1 == 0b1111111111111110
4097 // i16 rol(~1, 14) == 0b1011111111111111
4099 // Some additional tips to help conceptualize this transform:
4100 // - Try to see the operation as placing a single zero in a value of all ones.
4101 // - There exists no value for x which would allow the result to contain zero.
4102 // - Values of x larger than the bitwidth are undefined and do not require a
4103 // consistent result.
4104 // - Pushing the zero left requires shifting one bits in from the right.
4105 // A rotate left of ~1 is a nice way of achieving the desired result.
4106 if (TLI.isOperationLegalOrCustom(ISD::ROTL, VT) && N0.getOpcode() == ISD::SHL
4107 && isAllOnesConstant(N1) && isOneConstant(N0.getOperand(0))) {
4109 return DAG.getNode(ISD::ROTL, DL, VT, DAG.getConstant(~1, DL, VT),
4113 // Simplify: xor (op x...), (op y...) -> (op (xor x, y))
4114 if (N0.getOpcode() == N1.getOpcode()) {
4115 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
4116 if (Tmp.getNode()) return Tmp;
4119 // Simplify the expression using non-local knowledge.
4120 if (!VT.isVector() &&
4121 SimplifyDemandedBits(SDValue(N, 0)))
4122 return SDValue(N, 0);
4127 /// Handle transforms common to the three shifts, when the shift amount is a
4129 SDValue DAGCombiner::visitShiftByConstant(SDNode *N, ConstantSDNode *Amt) {
4130 SDNode *LHS = N->getOperand(0).getNode();
4131 if (!LHS->hasOneUse()) return SDValue();
4133 // We want to pull some binops through shifts, so that we have (and (shift))
4134 // instead of (shift (and)), likewise for add, or, xor, etc. This sort of
4135 // thing happens with address calculations, so it's important to canonicalize
4137 bool HighBitSet = false; // Can we transform this if the high bit is set?
4139 switch (LHS->getOpcode()) {
4140 default: return SDValue();
4143 HighBitSet = false; // We can only transform sra if the high bit is clear.
4146 HighBitSet = true; // We can only transform sra if the high bit is set.
4149 if (N->getOpcode() != ISD::SHL)
4150 return SDValue(); // only shl(add) not sr[al](add).
4151 HighBitSet = false; // We can only transform sra if the high bit is clear.
4155 // We require the RHS of the binop to be a constant and not opaque as well.
4156 ConstantSDNode *BinOpCst = getAsNonOpaqueConstant(LHS->getOperand(1));
4157 if (!BinOpCst) return SDValue();
4159 // FIXME: disable this unless the input to the binop is a shift by a constant.
4160 // If it is not a shift, it pessimizes some common cases like:
4162 // void foo(int *X, int i) { X[i & 1235] = 1; }
4163 // int bar(int *X, int i) { return X[i & 255]; }
4164 SDNode *BinOpLHSVal = LHS->getOperand(0).getNode();
4165 if ((BinOpLHSVal->getOpcode() != ISD::SHL &&
4166 BinOpLHSVal->getOpcode() != ISD::SRA &&
4167 BinOpLHSVal->getOpcode() != ISD::SRL) ||
4168 !isa<ConstantSDNode>(BinOpLHSVal->getOperand(1)))
4171 EVT VT = N->getValueType(0);
4173 // If this is a signed shift right, and the high bit is modified by the
4174 // logical operation, do not perform the transformation. The highBitSet
4175 // boolean indicates the value of the high bit of the constant which would
4176 // cause it to be modified for this operation.
4177 if (N->getOpcode() == ISD::SRA) {
4178 bool BinOpRHSSignSet = BinOpCst->getAPIntValue().isNegative();
4179 if (BinOpRHSSignSet != HighBitSet)
4183 if (!TLI.isDesirableToCommuteWithShift(LHS))
4186 // Fold the constants, shifting the binop RHS by the shift amount.
4187 SDValue NewRHS = DAG.getNode(N->getOpcode(), SDLoc(LHS->getOperand(1)),
4189 LHS->getOperand(1), N->getOperand(1));
4190 assert(isa<ConstantSDNode>(NewRHS) && "Folding was not successful!");
4192 // Create the new shift.
4193 SDValue NewShift = DAG.getNode(N->getOpcode(),
4194 SDLoc(LHS->getOperand(0)),
4195 VT, LHS->getOperand(0), N->getOperand(1));
4197 // Create the new binop.
4198 return DAG.getNode(LHS->getOpcode(), SDLoc(N), VT, NewShift, NewRHS);
4201 SDValue DAGCombiner::distributeTruncateThroughAnd(SDNode *N) {
4202 assert(N->getOpcode() == ISD::TRUNCATE);
4203 assert(N->getOperand(0).getOpcode() == ISD::AND);
4205 // (truncate:TruncVT (and N00, N01C)) -> (and (truncate:TruncVT N00), TruncC)
4206 if (N->hasOneUse() && N->getOperand(0).hasOneUse()) {
4207 SDValue N01 = N->getOperand(0).getOperand(1);
4209 if (ConstantSDNode *N01C = isConstOrConstSplat(N01)) {
4210 if (!N01C->isOpaque()) {
4211 EVT TruncVT = N->getValueType(0);
4212 SDValue N00 = N->getOperand(0).getOperand(0);
4213 APInt TruncC = N01C->getAPIntValue();
4214 TruncC = TruncC.trunc(TruncVT.getScalarSizeInBits());
4217 return DAG.getNode(ISD::AND, DL, TruncVT,
4218 DAG.getNode(ISD::TRUNCATE, DL, TruncVT, N00),
4219 DAG.getConstant(TruncC, DL, TruncVT));
4227 SDValue DAGCombiner::visitRotate(SDNode *N) {
4228 // fold (rot* x, (trunc (and y, c))) -> (rot* x, (and (trunc y), (trunc c))).
4229 if (N->getOperand(1).getOpcode() == ISD::TRUNCATE &&
4230 N->getOperand(1).getOperand(0).getOpcode() == ISD::AND) {
4231 SDValue NewOp1 = distributeTruncateThroughAnd(N->getOperand(1).getNode());
4232 if (NewOp1.getNode())
4233 return DAG.getNode(N->getOpcode(), SDLoc(N), N->getValueType(0),
4234 N->getOperand(0), NewOp1);
4239 SDValue DAGCombiner::visitSHL(SDNode *N) {
4240 SDValue N0 = N->getOperand(0);
4241 SDValue N1 = N->getOperand(1);
4242 EVT VT = N0.getValueType();
4243 unsigned OpSizeInBits = VT.getScalarSizeInBits();
4246 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
4247 if (VT.isVector()) {
4248 if (SDValue FoldedVOp = SimplifyVBinOp(N))
4251 BuildVectorSDNode *N1CV = dyn_cast<BuildVectorSDNode>(N1);
4252 // If setcc produces all-one true value then:
4253 // (shl (and (setcc) N01CV) N1CV) -> (and (setcc) N01CV<<N1CV)
4254 if (N1CV && N1CV->isConstant()) {
4255 if (N0.getOpcode() == ISD::AND) {
4256 SDValue N00 = N0->getOperand(0);
4257 SDValue N01 = N0->getOperand(1);
4258 BuildVectorSDNode *N01CV = dyn_cast<BuildVectorSDNode>(N01);
4260 if (N01CV && N01CV->isConstant() && N00.getOpcode() == ISD::SETCC &&
4261 TLI.getBooleanContents(N00.getOperand(0).getValueType()) ==
4262 TargetLowering::ZeroOrNegativeOneBooleanContent) {
4263 if (SDValue C = DAG.FoldConstantArithmetic(ISD::SHL, SDLoc(N), VT,
4265 return DAG.getNode(ISD::AND, SDLoc(N), VT, N00, C);
4268 N1C = isConstOrConstSplat(N1);
4273 // fold (shl c1, c2) -> c1<<c2
4274 ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
4275 if (N0C && N1C && !N1C->isOpaque())
4276 return DAG.FoldConstantArithmetic(ISD::SHL, SDLoc(N), VT, N0C, N1C);
4277 // fold (shl 0, x) -> 0
4278 if (isNullConstant(N0))
4280 // fold (shl x, c >= size(x)) -> undef
4281 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
4282 return DAG.getUNDEF(VT);
4283 // fold (shl x, 0) -> x
4284 if (N1C && N1C->isNullValue())
4286 // fold (shl undef, x) -> 0
4287 if (N0.getOpcode() == ISD::UNDEF)
4288 return DAG.getConstant(0, SDLoc(N), VT);
4289 // if (shl x, c) is known to be zero, return 0
4290 if (DAG.MaskedValueIsZero(SDValue(N, 0),
4291 APInt::getAllOnesValue(OpSizeInBits)))
4292 return DAG.getConstant(0, SDLoc(N), VT);
4293 // fold (shl x, (trunc (and y, c))) -> (shl x, (and (trunc y), (trunc c))).
4294 if (N1.getOpcode() == ISD::TRUNCATE &&
4295 N1.getOperand(0).getOpcode() == ISD::AND) {
4296 SDValue NewOp1 = distributeTruncateThroughAnd(N1.getNode());
4297 if (NewOp1.getNode())
4298 return DAG.getNode(ISD::SHL, SDLoc(N), VT, N0, NewOp1);
4301 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
4302 return SDValue(N, 0);
4304 // fold (shl (shl x, c1), c2) -> 0 or (shl x, (add c1, c2))
4305 if (N1C && N0.getOpcode() == ISD::SHL) {
4306 if (ConstantSDNode *N0C1 = isConstOrConstSplat(N0.getOperand(1))) {
4307 uint64_t c1 = N0C1->getZExtValue();
4308 uint64_t c2 = N1C->getZExtValue();
4310 if (c1 + c2 >= OpSizeInBits)
4311 return DAG.getConstant(0, DL, VT);
4312 return DAG.getNode(ISD::SHL, DL, VT, N0.getOperand(0),
4313 DAG.getConstant(c1 + c2, DL, N1.getValueType()));
4317 // fold (shl (ext (shl x, c1)), c2) -> (ext (shl x, (add c1, c2)))
4318 // For this to be valid, the second form must not preserve any of the bits
4319 // that are shifted out by the inner shift in the first form. This means
4320 // the outer shift size must be >= the number of bits added by the ext.
4321 // As a corollary, we don't care what kind of ext it is.
4322 if (N1C && (N0.getOpcode() == ISD::ZERO_EXTEND ||
4323 N0.getOpcode() == ISD::ANY_EXTEND ||
4324 N0.getOpcode() == ISD::SIGN_EXTEND) &&
4325 N0.getOperand(0).getOpcode() == ISD::SHL) {
4326 SDValue N0Op0 = N0.getOperand(0);
4327 if (ConstantSDNode *N0Op0C1 = isConstOrConstSplat(N0Op0.getOperand(1))) {
4328 uint64_t c1 = N0Op0C1->getZExtValue();
4329 uint64_t c2 = N1C->getZExtValue();
4330 EVT InnerShiftVT = N0Op0.getValueType();
4331 uint64_t InnerShiftSize = InnerShiftVT.getScalarSizeInBits();
4332 if (c2 >= OpSizeInBits - InnerShiftSize) {
4334 if (c1 + c2 >= OpSizeInBits)
4335 return DAG.getConstant(0, DL, VT);
4336 return DAG.getNode(ISD::SHL, DL, VT,
4337 DAG.getNode(N0.getOpcode(), DL, VT,
4338 N0Op0->getOperand(0)),
4339 DAG.getConstant(c1 + c2, DL, N1.getValueType()));
4344 // fold (shl (zext (srl x, C)), C) -> (zext (shl (srl x, C), C))
4345 // Only fold this if the inner zext has no other uses to avoid increasing
4346 // the total number of instructions.
4347 if (N1C && N0.getOpcode() == ISD::ZERO_EXTEND && N0.hasOneUse() &&
4348 N0.getOperand(0).getOpcode() == ISD::SRL) {
4349 SDValue N0Op0 = N0.getOperand(0);
4350 if (ConstantSDNode *N0Op0C1 = isConstOrConstSplat(N0Op0.getOperand(1))) {
4351 uint64_t c1 = N0Op0C1->getZExtValue();
4352 if (c1 < VT.getScalarSizeInBits()) {
4353 uint64_t c2 = N1C->getZExtValue();
4355 SDValue NewOp0 = N0.getOperand(0);
4356 EVT CountVT = NewOp0.getOperand(1).getValueType();
4358 SDValue NewSHL = DAG.getNode(ISD::SHL, DL, NewOp0.getValueType(),
4360 DAG.getConstant(c2, DL, CountVT));
4361 AddToWorklist(NewSHL.getNode());
4362 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N0), VT, NewSHL);
4368 // fold (shl (sr[la] exact X, C1), C2) -> (shl X, (C2-C1)) if C1 <= C2
4369 // fold (shl (sr[la] exact X, C1), C2) -> (sr[la] X, (C2-C1)) if C1 > C2
4370 if (N1C && (N0.getOpcode() == ISD::SRL || N0.getOpcode() == ISD::SRA) &&
4371 cast<BinaryWithFlagsSDNode>(N0)->Flags.hasExact()) {
4372 if (ConstantSDNode *N0C1 = isConstOrConstSplat(N0.getOperand(1))) {
4373 uint64_t C1 = N0C1->getZExtValue();
4374 uint64_t C2 = N1C->getZExtValue();
4377 return DAG.getNode(ISD::SHL, DL, VT, N0.getOperand(0),
4378 DAG.getConstant(C2 - C1, DL, N1.getValueType()));
4379 return DAG.getNode(N0.getOpcode(), DL, VT, N0.getOperand(0),
4380 DAG.getConstant(C1 - C2, DL, N1.getValueType()));
4384 // fold (shl (srl x, c1), c2) -> (and (shl x, (sub c2, c1), MASK) or
4385 // (and (srl x, (sub c1, c2), MASK)
4386 // Only fold this if the inner shift has no other uses -- if it does, folding
4387 // this will increase the total number of instructions.
4388 if (N1C && N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
4389 if (ConstantSDNode *N0C1 = isConstOrConstSplat(N0.getOperand(1))) {
4390 uint64_t c1 = N0C1->getZExtValue();
4391 if (c1 < OpSizeInBits) {
4392 uint64_t c2 = N1C->getZExtValue();
4393 APInt Mask = APInt::getHighBitsSet(OpSizeInBits, OpSizeInBits - c1);
4396 Mask = Mask.shl(c2 - c1);
4398 Shift = DAG.getNode(ISD::SHL, DL, VT, N0.getOperand(0),
4399 DAG.getConstant(c2 - c1, DL, N1.getValueType()));
4401 Mask = Mask.lshr(c1 - c2);
4403 Shift = DAG.getNode(ISD::SRL, DL, VT, N0.getOperand(0),
4404 DAG.getConstant(c1 - c2, DL, N1.getValueType()));
4407 return DAG.getNode(ISD::AND, DL, VT, Shift,
4408 DAG.getConstant(Mask, DL, VT));
4412 // fold (shl (sra x, c1), c1) -> (and x, (shl -1, c1))
4413 if (N1C && N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1)) {
4414 unsigned BitSize = VT.getScalarSizeInBits();
4416 SDValue HiBitsMask =
4417 DAG.getConstant(APInt::getHighBitsSet(BitSize,
4418 BitSize - N1C->getZExtValue()),
4420 return DAG.getNode(ISD::AND, DL, VT, N0.getOperand(0),
4424 // fold (shl (add x, c1), c2) -> (add (shl x, c2), c1 << c2)
4425 // Variant of version done on multiply, except mul by a power of 2 is turned
4428 if (N1C && N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse() &&
4429 (isa<ConstantSDNode>(N0.getOperand(1)) ||
4430 isConstantSplatVector(N0.getOperand(1).getNode(), Val))) {
4431 SDValue Shl0 = DAG.getNode(ISD::SHL, SDLoc(N0), VT, N0.getOperand(0), N1);
4432 SDValue Shl1 = DAG.getNode(ISD::SHL, SDLoc(N1), VT, N0.getOperand(1), N1);
4433 return DAG.getNode(ISD::ADD, SDLoc(N), VT, Shl0, Shl1);
4436 if (N1C && !N1C->isOpaque()) {
4437 SDValue NewSHL = visitShiftByConstant(N, N1C);
4438 if (NewSHL.getNode())
4445 SDValue DAGCombiner::visitSRA(SDNode *N) {
4446 SDValue N0 = N->getOperand(0);
4447 SDValue N1 = N->getOperand(1);
4448 EVT VT = N0.getValueType();
4449 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
4452 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
4453 if (VT.isVector()) {
4454 if (SDValue FoldedVOp = SimplifyVBinOp(N))
4457 N1C = isConstOrConstSplat(N1);
4460 // fold (sra c1, c2) -> (sra c1, c2)
4461 ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
4462 if (N0C && N1C && !N1C->isOpaque())
4463 return DAG.FoldConstantArithmetic(ISD::SRA, SDLoc(N), VT, N0C, N1C);
4464 // fold (sra 0, x) -> 0
4465 if (isNullConstant(N0))
4467 // fold (sra -1, x) -> -1
4468 if (isAllOnesConstant(N0))
4470 // fold (sra x, (setge c, size(x))) -> undef
4471 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
4472 return DAG.getUNDEF(VT);
4473 // fold (sra x, 0) -> x
4474 if (N1C && N1C->isNullValue())
4476 // fold (sra (shl x, c1), c1) -> sext_inreg for some c1 and target supports
4478 if (N1C && N0.getOpcode() == ISD::SHL && N1 == N0.getOperand(1)) {
4479 unsigned LowBits = OpSizeInBits - (unsigned)N1C->getZExtValue();
4480 EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), LowBits);
4482 ExtVT = EVT::getVectorVT(*DAG.getContext(),
4483 ExtVT, VT.getVectorNumElements());
4484 if ((!LegalOperations ||
4485 TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, ExtVT)))
4486 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
4487 N0.getOperand(0), DAG.getValueType(ExtVT));
4490 // fold (sra (sra x, c1), c2) -> (sra x, (add c1, c2))
4491 if (N1C && N0.getOpcode() == ISD::SRA) {
4492 if (ConstantSDNode *C1 = isConstOrConstSplat(N0.getOperand(1))) {
4493 unsigned Sum = N1C->getZExtValue() + C1->getZExtValue();
4494 if (Sum >= OpSizeInBits)
4495 Sum = OpSizeInBits - 1;
4497 return DAG.getNode(ISD::SRA, DL, VT, N0.getOperand(0),
4498 DAG.getConstant(Sum, DL, N1.getValueType()));
4502 // fold (sra (shl X, m), (sub result_size, n))
4503 // -> (sign_extend (trunc (shl X, (sub (sub result_size, n), m)))) for
4504 // result_size - n != m.
4505 // If truncate is free for the target sext(shl) is likely to result in better
4507 if (N0.getOpcode() == ISD::SHL && N1C) {
4508 // Get the two constanst of the shifts, CN0 = m, CN = n.
4509 const ConstantSDNode *N01C = isConstOrConstSplat(N0.getOperand(1));
4511 LLVMContext &Ctx = *DAG.getContext();
4512 // Determine what the truncate's result bitsize and type would be.
4513 EVT TruncVT = EVT::getIntegerVT(Ctx, OpSizeInBits - N1C->getZExtValue());
4516 TruncVT = EVT::getVectorVT(Ctx, TruncVT, VT.getVectorNumElements());
4518 // Determine the residual right-shift amount.
4519 signed ShiftAmt = N1C->getZExtValue() - N01C->getZExtValue();
4521 // If the shift is not a no-op (in which case this should be just a sign
4522 // extend already), the truncated to type is legal, sign_extend is legal
4523 // on that type, and the truncate to that type is both legal and free,
4524 // perform the transform.
4525 if ((ShiftAmt > 0) &&
4526 TLI.isOperationLegalOrCustom(ISD::SIGN_EXTEND, TruncVT) &&
4527 TLI.isOperationLegalOrCustom(ISD::TRUNCATE, VT) &&
4528 TLI.isTruncateFree(VT, TruncVT)) {
4531 SDValue Amt = DAG.getConstant(ShiftAmt, DL,
4532 getShiftAmountTy(N0.getOperand(0).getValueType()));
4533 SDValue Shift = DAG.getNode(ISD::SRL, DL, VT,
4534 N0.getOperand(0), Amt);
4535 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, DL, TruncVT,
4537 return DAG.getNode(ISD::SIGN_EXTEND, DL,
4538 N->getValueType(0), Trunc);
4543 // fold (sra x, (trunc (and y, c))) -> (sra x, (and (trunc y), (trunc c))).
4544 if (N1.getOpcode() == ISD::TRUNCATE &&
4545 N1.getOperand(0).getOpcode() == ISD::AND) {
4546 SDValue NewOp1 = distributeTruncateThroughAnd(N1.getNode());
4547 if (NewOp1.getNode())
4548 return DAG.getNode(ISD::SRA, SDLoc(N), VT, N0, NewOp1);
4551 // fold (sra (trunc (srl x, c1)), c2) -> (trunc (sra x, c1 + c2))
4552 // if c1 is equal to the number of bits the trunc removes
4553 if (N0.getOpcode() == ISD::TRUNCATE &&
4554 (N0.getOperand(0).getOpcode() == ISD::SRL ||
4555 N0.getOperand(0).getOpcode() == ISD::SRA) &&
4556 N0.getOperand(0).hasOneUse() &&
4557 N0.getOperand(0).getOperand(1).hasOneUse() &&
4559 SDValue N0Op0 = N0.getOperand(0);
4560 if (ConstantSDNode *LargeShift = isConstOrConstSplat(N0Op0.getOperand(1))) {
4561 unsigned LargeShiftVal = LargeShift->getZExtValue();
4562 EVT LargeVT = N0Op0.getValueType();
4564 if (LargeVT.getScalarSizeInBits() - OpSizeInBits == LargeShiftVal) {
4567 DAG.getConstant(LargeShiftVal + N1C->getZExtValue(), DL,
4568 getShiftAmountTy(N0Op0.getOperand(0).getValueType()));
4569 SDValue SRA = DAG.getNode(ISD::SRA, DL, LargeVT,
4570 N0Op0.getOperand(0), Amt);
4571 return DAG.getNode(ISD::TRUNCATE, DL, VT, SRA);
4576 // Simplify, based on bits shifted out of the LHS.
4577 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
4578 return SDValue(N, 0);
4581 // If the sign bit is known to be zero, switch this to a SRL.
4582 if (DAG.SignBitIsZero(N0))
4583 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0, N1);
4585 if (N1C && !N1C->isOpaque()) {
4586 SDValue NewSRA = visitShiftByConstant(N, N1C);
4587 if (NewSRA.getNode())
4594 SDValue DAGCombiner::visitSRL(SDNode *N) {
4595 SDValue N0 = N->getOperand(0);
4596 SDValue N1 = N->getOperand(1);
4597 EVT VT = N0.getValueType();
4598 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
4601 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
4602 if (VT.isVector()) {
4603 if (SDValue FoldedVOp = SimplifyVBinOp(N))
4606 N1C = isConstOrConstSplat(N1);
4609 // fold (srl c1, c2) -> c1 >>u c2
4610 ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
4611 if (N0C && N1C && !N1C->isOpaque())
4612 return DAG.FoldConstantArithmetic(ISD::SRL, SDLoc(N), VT, N0C, N1C);
4613 // fold (srl 0, x) -> 0
4614 if (isNullConstant(N0))
4616 // fold (srl x, c >= size(x)) -> undef
4617 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
4618 return DAG.getUNDEF(VT);
4619 // fold (srl x, 0) -> x
4620 if (N1C && N1C->isNullValue())
4622 // if (srl x, c) is known to be zero, return 0
4623 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
4624 APInt::getAllOnesValue(OpSizeInBits)))
4625 return DAG.getConstant(0, SDLoc(N), VT);
4627 // fold (srl (srl x, c1), c2) -> 0 or (srl x, (add c1, c2))
4628 if (N1C && N0.getOpcode() == ISD::SRL) {
4629 if (ConstantSDNode *N01C = isConstOrConstSplat(N0.getOperand(1))) {
4630 uint64_t c1 = N01C->getZExtValue();
4631 uint64_t c2 = N1C->getZExtValue();
4633 if (c1 + c2 >= OpSizeInBits)
4634 return DAG.getConstant(0, DL, VT);
4635 return DAG.getNode(ISD::SRL, DL, VT, N0.getOperand(0),
4636 DAG.getConstant(c1 + c2, DL, N1.getValueType()));
4640 // fold (srl (trunc (srl x, c1)), c2) -> 0 or (trunc (srl x, (add c1, c2)))
4641 if (N1C && N0.getOpcode() == ISD::TRUNCATE &&
4642 N0.getOperand(0).getOpcode() == ISD::SRL &&
4643 isa<ConstantSDNode>(N0.getOperand(0)->getOperand(1))) {
4645 cast<ConstantSDNode>(N0.getOperand(0)->getOperand(1))->getZExtValue();
4646 uint64_t c2 = N1C->getZExtValue();
4647 EVT InnerShiftVT = N0.getOperand(0).getValueType();
4648 EVT ShiftCountVT = N0.getOperand(0)->getOperand(1).getValueType();
4649 uint64_t InnerShiftSize = InnerShiftVT.getScalarType().getSizeInBits();
4650 // This is only valid if the OpSizeInBits + c1 = size of inner shift.
4651 if (c1 + OpSizeInBits == InnerShiftSize) {
4653 if (c1 + c2 >= InnerShiftSize)
4654 return DAG.getConstant(0, DL, VT);
4655 return DAG.getNode(ISD::TRUNCATE, DL, VT,
4656 DAG.getNode(ISD::SRL, DL, InnerShiftVT,
4657 N0.getOperand(0)->getOperand(0),
4658 DAG.getConstant(c1 + c2, DL,
4663 // fold (srl (shl x, c), c) -> (and x, cst2)
4664 if (N1C && N0.getOpcode() == ISD::SHL && N0.getOperand(1) == N1) {
4665 unsigned BitSize = N0.getScalarValueSizeInBits();
4666 if (BitSize <= 64) {
4667 uint64_t ShAmt = N1C->getZExtValue() + 64 - BitSize;
4669 return DAG.getNode(ISD::AND, DL, VT, N0.getOperand(0),
4670 DAG.getConstant(~0ULL >> ShAmt, DL, VT));
4674 // fold (srl (anyextend x), c) -> (and (anyextend (srl x, c)), mask)
4675 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
4676 // Shifting in all undef bits?
4677 EVT SmallVT = N0.getOperand(0).getValueType();
4678 unsigned BitSize = SmallVT.getScalarSizeInBits();
4679 if (N1C->getZExtValue() >= BitSize)
4680 return DAG.getUNDEF(VT);
4682 if (!LegalTypes || TLI.isTypeDesirableForOp(ISD::SRL, SmallVT)) {
4683 uint64_t ShiftAmt = N1C->getZExtValue();
4685 SDValue SmallShift = DAG.getNode(ISD::SRL, DL0, SmallVT,
4687 DAG.getConstant(ShiftAmt, DL0,
4688 getShiftAmountTy(SmallVT)));
4689 AddToWorklist(SmallShift.getNode());
4690 APInt Mask = APInt::getAllOnesValue(OpSizeInBits).lshr(ShiftAmt);
4692 return DAG.getNode(ISD::AND, DL, VT,
4693 DAG.getNode(ISD::ANY_EXTEND, DL, VT, SmallShift),
4694 DAG.getConstant(Mask, DL, VT));
4698 // fold (srl (sra X, Y), 31) -> (srl X, 31). This srl only looks at the sign
4699 // bit, which is unmodified by sra.
4700 if (N1C && N1C->getZExtValue() + 1 == OpSizeInBits) {
4701 if (N0.getOpcode() == ISD::SRA)
4702 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0.getOperand(0), N1);
4705 // fold (srl (ctlz x), "5") -> x iff x has one bit set (the low bit).
4706 if (N1C && N0.getOpcode() == ISD::CTLZ &&
4707 N1C->getAPIntValue() == Log2_32(OpSizeInBits)) {
4708 APInt KnownZero, KnownOne;
4709 DAG.computeKnownBits(N0.getOperand(0), KnownZero, KnownOne);
4711 // If any of the input bits are KnownOne, then the input couldn't be all
4712 // zeros, thus the result of the srl will always be zero.
4713 if (KnownOne.getBoolValue()) return DAG.getConstant(0, SDLoc(N0), VT);
4715 // If all of the bits input the to ctlz node are known to be zero, then
4716 // the result of the ctlz is "32" and the result of the shift is one.
4717 APInt UnknownBits = ~KnownZero;
4718 if (UnknownBits == 0) return DAG.getConstant(1, SDLoc(N0), VT);
4720 // Otherwise, check to see if there is exactly one bit input to the ctlz.
4721 if ((UnknownBits & (UnknownBits - 1)) == 0) {
4722 // Okay, we know that only that the single bit specified by UnknownBits
4723 // could be set on input to the CTLZ node. If this bit is set, the SRL
4724 // will return 0, if it is clear, it returns 1. Change the CTLZ/SRL pair
4725 // to an SRL/XOR pair, which is likely to simplify more.
4726 unsigned ShAmt = UnknownBits.countTrailingZeros();
4727 SDValue Op = N0.getOperand(0);
4731 Op = DAG.getNode(ISD::SRL, DL, VT, Op,
4732 DAG.getConstant(ShAmt, DL,
4733 getShiftAmountTy(Op.getValueType())));
4734 AddToWorklist(Op.getNode());
4738 return DAG.getNode(ISD::XOR, DL, VT,
4739 Op, DAG.getConstant(1, DL, VT));
4743 // fold (srl x, (trunc (and y, c))) -> (srl x, (and (trunc y), (trunc c))).
4744 if (N1.getOpcode() == ISD::TRUNCATE &&
4745 N1.getOperand(0).getOpcode() == ISD::AND) {
4746 SDValue NewOp1 = distributeTruncateThroughAnd(N1.getNode());
4747 if (NewOp1.getNode())
4748 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0, NewOp1);
4751 // fold operands of srl based on knowledge that the low bits are not
4753 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
4754 return SDValue(N, 0);
4756 if (N1C && !N1C->isOpaque()) {
4757 SDValue NewSRL = visitShiftByConstant(N, N1C);
4758 if (NewSRL.getNode())
4762 // Attempt to convert a srl of a load into a narrower zero-extending load.
4763 SDValue NarrowLoad = ReduceLoadWidth(N);
4764 if (NarrowLoad.getNode())
4767 // Here is a common situation. We want to optimize:
4770 // %b = and i32 %a, 2
4771 // %c = srl i32 %b, 1
4772 // brcond i32 %c ...
4778 // %c = setcc eq %b, 0
4781 // However when after the source operand of SRL is optimized into AND, the SRL
4782 // itself may not be optimized further. Look for it and add the BRCOND into
4784 if (N->hasOneUse()) {
4785 SDNode *Use = *N->use_begin();
4786 if (Use->getOpcode() == ISD::BRCOND)
4788 else if (Use->getOpcode() == ISD::TRUNCATE && Use->hasOneUse()) {
4789 // Also look pass the truncate.
4790 Use = *Use->use_begin();
4791 if (Use->getOpcode() == ISD::BRCOND)
4799 SDValue DAGCombiner::visitBSWAP(SDNode *N) {
4800 SDValue N0 = N->getOperand(0);
4801 EVT VT = N->getValueType(0);
4803 // fold (bswap c1) -> c2
4804 if (isConstantIntBuildVectorOrConstantInt(N0))
4805 return DAG.getNode(ISD::BSWAP, SDLoc(N), VT, N0);
4806 // fold (bswap (bswap x)) -> x
4807 if (N0.getOpcode() == ISD::BSWAP)
4808 return N0->getOperand(0);
4812 SDValue DAGCombiner::visitCTLZ(SDNode *N) {
4813 SDValue N0 = N->getOperand(0);
4814 EVT VT = N->getValueType(0);
4816 // fold (ctlz c1) -> c2
4817 if (isConstantIntBuildVectorOrConstantInt(N0))
4818 return DAG.getNode(ISD::CTLZ, SDLoc(N), VT, N0);
4822 SDValue DAGCombiner::visitCTLZ_ZERO_UNDEF(SDNode *N) {
4823 SDValue N0 = N->getOperand(0);
4824 EVT VT = N->getValueType(0);
4826 // fold (ctlz_zero_undef c1) -> c2
4827 if (isConstantIntBuildVectorOrConstantInt(N0))
4828 return DAG.getNode(ISD::CTLZ_ZERO_UNDEF, SDLoc(N), VT, N0);
4832 SDValue DAGCombiner::visitCTTZ(SDNode *N) {
4833 SDValue N0 = N->getOperand(0);
4834 EVT VT = N->getValueType(0);
4836 // fold (cttz c1) -> c2
4837 if (isConstantIntBuildVectorOrConstantInt(N0))
4838 return DAG.getNode(ISD::CTTZ, SDLoc(N), VT, N0);
4842 SDValue DAGCombiner::visitCTTZ_ZERO_UNDEF(SDNode *N) {
4843 SDValue N0 = N->getOperand(0);
4844 EVT VT = N->getValueType(0);
4846 // fold (cttz_zero_undef c1) -> c2
4847 if (isConstantIntBuildVectorOrConstantInt(N0))
4848 return DAG.getNode(ISD::CTTZ_ZERO_UNDEF, SDLoc(N), VT, N0);
4852 SDValue DAGCombiner::visitCTPOP(SDNode *N) {
4853 SDValue N0 = N->getOperand(0);
4854 EVT VT = N->getValueType(0);
4856 // fold (ctpop c1) -> c2
4857 if (isConstantIntBuildVectorOrConstantInt(N0))
4858 return DAG.getNode(ISD::CTPOP, SDLoc(N), VT, N0);
4863 /// \brief Generate Min/Max node
4864 static SDValue combineMinNumMaxNum(SDLoc DL, EVT VT, SDValue LHS, SDValue RHS,
4865 SDValue True, SDValue False,
4866 ISD::CondCode CC, const TargetLowering &TLI,
4867 SelectionDAG &DAG) {
4868 if (!(LHS == True && RHS == False) && !(LHS == False && RHS == True))
4878 unsigned Opcode = (LHS == True) ? ISD::FMINNUM : ISD::FMAXNUM;
4879 if (TLI.isOperationLegal(Opcode, VT))
4880 return DAG.getNode(Opcode, DL, VT, LHS, RHS);
4889 unsigned Opcode = (LHS == True) ? ISD::FMAXNUM : ISD::FMINNUM;
4890 if (TLI.isOperationLegal(Opcode, VT))
4891 return DAG.getNode(Opcode, DL, VT, LHS, RHS);
4899 SDValue DAGCombiner::visitSELECT(SDNode *N) {
4900 SDValue N0 = N->getOperand(0);
4901 SDValue N1 = N->getOperand(1);
4902 SDValue N2 = N->getOperand(2);
4903 EVT VT = N->getValueType(0);
4904 EVT VT0 = N0.getValueType();
4906 // fold (select C, X, X) -> X
4909 if (const ConstantSDNode *N0C = dyn_cast<const ConstantSDNode>(N0)) {
4910 // fold (select true, X, Y) -> X
4911 // fold (select false, X, Y) -> Y
4912 return !N0C->isNullValue() ? N1 : N2;
4914 // fold (select C, 1, X) -> (or C, X)
4915 if (VT == MVT::i1 && isOneConstant(N1))
4916 return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N2);
4917 // fold (select C, 0, 1) -> (xor C, 1)
4918 // We can't do this reliably if integer based booleans have different contents
4919 // to floating point based booleans. This is because we can't tell whether we
4920 // have an integer-based boolean or a floating-point-based boolean unless we
4921 // can find the SETCC that produced it and inspect its operands. This is
4922 // fairly easy if C is the SETCC node, but it can potentially be
4923 // undiscoverable (or not reasonably discoverable). For example, it could be
4924 // in another basic block or it could require searching a complicated
4926 if (VT.isInteger() &&
4927 (VT0 == MVT::i1 || (VT0.isInteger() &&
4928 TLI.getBooleanContents(false, false) ==
4929 TLI.getBooleanContents(false, true) &&
4930 TLI.getBooleanContents(false, false) ==
4931 TargetLowering::ZeroOrOneBooleanContent)) &&
4932 isNullConstant(N1) && isOneConstant(N2)) {
4936 return DAG.getNode(ISD::XOR, DL, VT0,
4937 N0, DAG.getConstant(1, DL, VT0));
4940 XORNode = DAG.getNode(ISD::XOR, DL0, VT0,
4941 N0, DAG.getConstant(1, DL0, VT0));
4942 AddToWorklist(XORNode.getNode());
4944 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, XORNode);
4945 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, XORNode);
4947 // fold (select C, 0, X) -> (and (not C), X)
4948 if (VT == VT0 && VT == MVT::i1 && isNullConstant(N1)) {
4949 SDValue NOTNode = DAG.getNOT(SDLoc(N0), N0, VT);
4950 AddToWorklist(NOTNode.getNode());
4951 return DAG.getNode(ISD::AND, SDLoc(N), VT, NOTNode, N2);
4953 // fold (select C, X, 1) -> (or (not C), X)
4954 if (VT == VT0 && VT == MVT::i1 && isOneConstant(N2)) {
4955 SDValue NOTNode = DAG.getNOT(SDLoc(N0), N0, VT);
4956 AddToWorklist(NOTNode.getNode());
4957 return DAG.getNode(ISD::OR, SDLoc(N), VT, NOTNode, N1);
4959 // fold (select C, X, 0) -> (and C, X)
4960 if (VT == MVT::i1 && isNullConstant(N2))
4961 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0, N1);
4962 // fold (select X, X, Y) -> (or X, Y)
4963 // fold (select X, 1, Y) -> (or X, Y)
4964 if (VT == MVT::i1 && (N0 == N1 || isOneConstant(N1)))
4965 return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N2);
4966 // fold (select X, Y, X) -> (and X, Y)
4967 // fold (select X, Y, 0) -> (and X, Y)
4968 if (VT == MVT::i1 && (N0 == N2 || isNullConstant(N2)))
4969 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0, N1);
4971 // If we can fold this based on the true/false value, do so.
4972 if (SimplifySelectOps(N, N1, N2))
4973 return SDValue(N, 0); // Don't revisit N.
4975 // fold selects based on a setcc into other things, such as min/max/abs
4976 if (N0.getOpcode() == ISD::SETCC) {
4977 // select x, y (fcmp lt x, y) -> fminnum x, y
4978 // select x, y (fcmp gt x, y) -> fmaxnum x, y
4980 // This is OK if we don't care about what happens if either operand is a
4984 // FIXME: Instead of testing for UnsafeFPMath, this should be checking for
4985 // no signed zeros as well as no nans.
4986 const TargetOptions &Options = DAG.getTarget().Options;
4987 if (Options.UnsafeFPMath &&
4988 VT.isFloatingPoint() && N0.hasOneUse() &&
4989 DAG.isKnownNeverNaN(N1) && DAG.isKnownNeverNaN(N2)) {
4990 ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
4993 combineMinNumMaxNum(SDLoc(N), VT, N0.getOperand(0), N0.getOperand(1),
4994 N1, N2, CC, TLI, DAG);
4999 if ((!LegalOperations &&
5000 TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT)) ||
5001 TLI.isOperationLegal(ISD::SELECT_CC, VT))
5002 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), VT,
5003 N0.getOperand(0), N0.getOperand(1),
5004 N1, N2, N0.getOperand(2));
5005 return SimplifySelect(SDLoc(N), N0, N1, N2);
5008 if (VT0 == MVT::i1) {
5009 if (TLI.shouldNormalizeToSelectSequence(*DAG.getContext(), VT)) {
5010 // select (and Cond0, Cond1), X, Y
5011 // -> select Cond0, (select Cond1, X, Y), Y
5012 if (N0->getOpcode() == ISD::AND && N0->hasOneUse()) {
5013 SDValue Cond0 = N0->getOperand(0);
5014 SDValue Cond1 = N0->getOperand(1);
5015 SDValue InnerSelect = DAG.getNode(ISD::SELECT, SDLoc(N),
5016 N1.getValueType(), Cond1, N1, N2);
5017 return DAG.getNode(ISD::SELECT, SDLoc(N), N1.getValueType(), Cond0,
5020 // select (or Cond0, Cond1), X, Y -> select Cond0, X, (select Cond1, X, Y)
5021 if (N0->getOpcode() == ISD::OR && N0->hasOneUse()) {
5022 SDValue Cond0 = N0->getOperand(0);
5023 SDValue Cond1 = N0->getOperand(1);
5024 SDValue InnerSelect = DAG.getNode(ISD::SELECT, SDLoc(N),
5025 N1.getValueType(), Cond1, N1, N2);
5026 return DAG.getNode(ISD::SELECT, SDLoc(N), N1.getValueType(), Cond0, N1,
5031 // select Cond0, (select Cond1, X, Y), Y -> select (and Cond0, Cond1), X, Y
5032 if (N1->getOpcode() == ISD::SELECT) {
5033 SDValue N1_0 = N1->getOperand(0);
5034 SDValue N1_1 = N1->getOperand(1);
5035 SDValue N1_2 = N1->getOperand(2);
5036 if (N1_2 == N2 && N0.getValueType() == N1_0.getValueType()) {
5037 // Create the actual and node if we can generate good code for it.
5038 if (!TLI.shouldNormalizeToSelectSequence(*DAG.getContext(), VT)) {
5039 SDValue And = DAG.getNode(ISD::AND, SDLoc(N), N0.getValueType(),
5041 return DAG.getNode(ISD::SELECT, SDLoc(N), N1.getValueType(), And,
5044 // Otherwise see if we can optimize the "and" to a better pattern.
5045 if (SDValue Combined = visitANDLike(N0, N1_0, N))
5046 return DAG.getNode(ISD::SELECT, SDLoc(N), N1.getValueType(), Combined,
5050 // select Cond0, X, (select Cond1, X, Y) -> select (or Cond0, Cond1), X, Y
5051 if (N2->getOpcode() == ISD::SELECT) {
5052 SDValue N2_0 = N2->getOperand(0);
5053 SDValue N2_1 = N2->getOperand(1);
5054 SDValue N2_2 = N2->getOperand(2);
5055 if (N2_1 == N1 && N0.getValueType() == N2_0.getValueType()) {
5056 // Create the actual or node if we can generate good code for it.
5057 if (!TLI.shouldNormalizeToSelectSequence(*DAG.getContext(), VT)) {
5058 SDValue Or = DAG.getNode(ISD::OR, SDLoc(N), N0.getValueType(),
5060 return DAG.getNode(ISD::SELECT, SDLoc(N), N1.getValueType(), Or,
5063 // Otherwise see if we can optimize to a better pattern.
5064 if (SDValue Combined = visitORLike(N0, N2_0, N))
5065 return DAG.getNode(ISD::SELECT, SDLoc(N), N1.getValueType(), Combined,
5075 std::pair<SDValue, SDValue> SplitVSETCC(const SDNode *N, SelectionDAG &DAG) {
5078 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(N->getValueType(0));
5080 // Split the inputs.
5081 SDValue Lo, Hi, LL, LH, RL, RH;
5082 std::tie(LL, LH) = DAG.SplitVectorOperand(N, 0);
5083 std::tie(RL, RH) = DAG.SplitVectorOperand(N, 1);
5085 Lo = DAG.getNode(N->getOpcode(), DL, LoVT, LL, RL, N->getOperand(2));
5086 Hi = DAG.getNode(N->getOpcode(), DL, HiVT, LH, RH, N->getOperand(2));
5088 return std::make_pair(Lo, Hi);
5091 // This function assumes all the vselect's arguments are CONCAT_VECTOR
5092 // nodes and that the condition is a BV of ConstantSDNodes (or undefs).
5093 static SDValue ConvertSelectToConcatVector(SDNode *N, SelectionDAG &DAG) {
5095 SDValue Cond = N->getOperand(0);
5096 SDValue LHS = N->getOperand(1);
5097 SDValue RHS = N->getOperand(2);
5098 EVT VT = N->getValueType(0);
5099 int NumElems = VT.getVectorNumElements();
5100 assert(LHS.getOpcode() == ISD::CONCAT_VECTORS &&
5101 RHS.getOpcode() == ISD::CONCAT_VECTORS &&
5102 Cond.getOpcode() == ISD::BUILD_VECTOR);
5104 // CONCAT_VECTOR can take an arbitrary number of arguments. We only care about
5105 // binary ones here.
5106 if (LHS->getNumOperands() != 2 || RHS->getNumOperands() != 2)
5109 // We're sure we have an even number of elements due to the
5110 // concat_vectors we have as arguments to vselect.
5111 // Skip BV elements until we find one that's not an UNDEF
5112 // After we find an UNDEF element, keep looping until we get to half the
5113 // length of the BV and see if all the non-undef nodes are the same.
5114 ConstantSDNode *BottomHalf = nullptr;
5115 for (int i = 0; i < NumElems / 2; ++i) {
5116 if (Cond->getOperand(i)->getOpcode() == ISD::UNDEF)
5119 if (BottomHalf == nullptr)
5120 BottomHalf = cast<ConstantSDNode>(Cond.getOperand(i));
5121 else if (Cond->getOperand(i).getNode() != BottomHalf)
5125 // Do the same for the second half of the BuildVector
5126 ConstantSDNode *TopHalf = nullptr;
5127 for (int i = NumElems / 2; i < NumElems; ++i) {
5128 if (Cond->getOperand(i)->getOpcode() == ISD::UNDEF)
5131 if (TopHalf == nullptr)
5132 TopHalf = cast<ConstantSDNode>(Cond.getOperand(i));
5133 else if (Cond->getOperand(i).getNode() != TopHalf)
5137 assert(TopHalf && BottomHalf &&
5138 "One half of the selector was all UNDEFs and the other was all the "
5139 "same value. This should have been addressed before this function.");
5141 ISD::CONCAT_VECTORS, dl, VT,
5142 BottomHalf->isNullValue() ? RHS->getOperand(0) : LHS->getOperand(0),
5143 TopHalf->isNullValue() ? RHS->getOperand(1) : LHS->getOperand(1));
5146 SDValue DAGCombiner::visitMSCATTER(SDNode *N) {
5148 if (Level >= AfterLegalizeTypes)
5151 MaskedScatterSDNode *MSC = cast<MaskedScatterSDNode>(N);
5152 SDValue Mask = MSC->getMask();
5153 SDValue Data = MSC->getValue();
5156 // If the MSCATTER data type requires splitting and the mask is provided by a
5157 // SETCC, then split both nodes and its operands before legalization. This
5158 // prevents the type legalizer from unrolling SETCC into scalar comparisons
5159 // and enables future optimizations (e.g. min/max pattern matching on X86).
5160 if (Mask.getOpcode() != ISD::SETCC)
5163 // Check if any splitting is required.
5164 if (TLI.getTypeAction(*DAG.getContext(), Data.getValueType()) !=
5165 TargetLowering::TypeSplitVector)
5167 SDValue MaskLo, MaskHi, Lo, Hi;
5168 std::tie(MaskLo, MaskHi) = SplitVSETCC(Mask.getNode(), DAG);
5171 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(MSC->getValueType(0));
5173 SDValue Chain = MSC->getChain();
5175 EVT MemoryVT = MSC->getMemoryVT();
5176 unsigned Alignment = MSC->getOriginalAlignment();
5178 EVT LoMemVT, HiMemVT;
5179 std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemoryVT);
5181 SDValue DataLo, DataHi;
5182 std::tie(DataLo, DataHi) = DAG.SplitVector(Data, DL);
5184 SDValue BasePtr = MSC->getBasePtr();
5185 SDValue IndexLo, IndexHi;
5186 std::tie(IndexLo, IndexHi) = DAG.SplitVector(MSC->getIndex(), DL);
5188 MachineMemOperand *MMO = DAG.getMachineFunction().
5189 getMachineMemOperand(MSC->getPointerInfo(),
5190 MachineMemOperand::MOStore, LoMemVT.getStoreSize(),
5191 Alignment, MSC->getAAInfo(), MSC->getRanges());
5193 SDValue OpsLo[] = { Chain, DataLo, MaskLo, BasePtr, IndexLo };
5194 Lo = DAG.getMaskedScatter(DAG.getVTList(MVT::Other), DataLo.getValueType(),
5197 SDValue OpsHi[] = {Chain, DataHi, MaskHi, BasePtr, IndexHi};
5198 Hi = DAG.getMaskedScatter(DAG.getVTList(MVT::Other), DataHi.getValueType(),
5201 AddToWorklist(Lo.getNode());
5202 AddToWorklist(Hi.getNode());
5204 return DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Lo, Hi);
5207 SDValue DAGCombiner::visitMSTORE(SDNode *N) {
5209 if (Level >= AfterLegalizeTypes)
5212 MaskedStoreSDNode *MST = dyn_cast<MaskedStoreSDNode>(N);
5213 SDValue Mask = MST->getMask();
5214 SDValue Data = MST->getValue();
5217 // If the MSTORE data type requires splitting and the mask is provided by a
5218 // SETCC, then split both nodes and its operands before legalization. This
5219 // prevents the type legalizer from unrolling SETCC into scalar comparisons
5220 // and enables future optimizations (e.g. min/max pattern matching on X86).
5221 if (Mask.getOpcode() == ISD::SETCC) {
5223 // Check if any splitting is required.
5224 if (TLI.getTypeAction(*DAG.getContext(), Data.getValueType()) !=
5225 TargetLowering::TypeSplitVector)
5228 SDValue MaskLo, MaskHi, Lo, Hi;
5229 std::tie(MaskLo, MaskHi) = SplitVSETCC(Mask.getNode(), DAG);
5232 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(MST->getValueType(0));
5234 SDValue Chain = MST->getChain();
5235 SDValue Ptr = MST->getBasePtr();
5237 EVT MemoryVT = MST->getMemoryVT();
5238 unsigned Alignment = MST->getOriginalAlignment();
5240 // if Alignment is equal to the vector size,
5241 // take the half of it for the second part
5242 unsigned SecondHalfAlignment =
5243 (Alignment == Data->getValueType(0).getSizeInBits()/8) ?
5244 Alignment/2 : Alignment;
5246 EVT LoMemVT, HiMemVT;
5247 std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemoryVT);
5249 SDValue DataLo, DataHi;
5250 std::tie(DataLo, DataHi) = DAG.SplitVector(Data, DL);
5252 MachineMemOperand *MMO = DAG.getMachineFunction().
5253 getMachineMemOperand(MST->getPointerInfo(),
5254 MachineMemOperand::MOStore, LoMemVT.getStoreSize(),
5255 Alignment, MST->getAAInfo(), MST->getRanges());
5257 Lo = DAG.getMaskedStore(Chain, DL, DataLo, Ptr, MaskLo, LoMemVT, MMO,
5258 MST->isTruncatingStore());
5260 unsigned IncrementSize = LoMemVT.getSizeInBits()/8;
5261 Ptr = DAG.getNode(ISD::ADD, DL, Ptr.getValueType(), Ptr,
5262 DAG.getConstant(IncrementSize, DL, Ptr.getValueType()));
5264 MMO = DAG.getMachineFunction().
5265 getMachineMemOperand(MST->getPointerInfo(),
5266 MachineMemOperand::MOStore, HiMemVT.getStoreSize(),
5267 SecondHalfAlignment, MST->getAAInfo(),
5270 Hi = DAG.getMaskedStore(Chain, DL, DataHi, Ptr, MaskHi, HiMemVT, MMO,
5271 MST->isTruncatingStore());
5273 AddToWorklist(Lo.getNode());
5274 AddToWorklist(Hi.getNode());
5276 return DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Lo, Hi);
5281 SDValue DAGCombiner::visitMGATHER(SDNode *N) {
5283 if (Level >= AfterLegalizeTypes)
5286 MaskedGatherSDNode *MGT = dyn_cast<MaskedGatherSDNode>(N);
5287 SDValue Mask = MGT->getMask();
5290 // If the MGATHER result requires splitting and the mask is provided by a
5291 // SETCC, then split both nodes and its operands before legalization. This
5292 // prevents the type legalizer from unrolling SETCC into scalar comparisons
5293 // and enables future optimizations (e.g. min/max pattern matching on X86).
5295 if (Mask.getOpcode() != ISD::SETCC)
5298 EVT VT = N->getValueType(0);
5300 // Check if any splitting is required.
5301 if (TLI.getTypeAction(*DAG.getContext(), VT) !=
5302 TargetLowering::TypeSplitVector)
5305 SDValue MaskLo, MaskHi, Lo, Hi;
5306 std::tie(MaskLo, MaskHi) = SplitVSETCC(Mask.getNode(), DAG);
5308 SDValue Src0 = MGT->getValue();
5309 SDValue Src0Lo, Src0Hi;
5310 std::tie(Src0Lo, Src0Hi) = DAG.SplitVector(Src0, DL);
5313 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(VT);
5315 SDValue Chain = MGT->getChain();
5316 EVT MemoryVT = MGT->getMemoryVT();
5317 unsigned Alignment = MGT->getOriginalAlignment();
5319 EVT LoMemVT, HiMemVT;
5320 std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemoryVT);
5322 SDValue BasePtr = MGT->getBasePtr();
5323 SDValue Index = MGT->getIndex();
5324 SDValue IndexLo, IndexHi;
5325 std::tie(IndexLo, IndexHi) = DAG.SplitVector(Index, DL);
5327 MachineMemOperand *MMO = DAG.getMachineFunction().
5328 getMachineMemOperand(MGT->getPointerInfo(),
5329 MachineMemOperand::MOLoad, LoMemVT.getStoreSize(),
5330 Alignment, MGT->getAAInfo(), MGT->getRanges());
5332 SDValue OpsLo[] = { Chain, Src0Lo, MaskLo, BasePtr, IndexLo };
5333 Lo = DAG.getMaskedGather(DAG.getVTList(LoVT, MVT::Other), LoVT, DL, OpsLo,
5336 SDValue OpsHi[] = {Chain, Src0Hi, MaskHi, BasePtr, IndexHi};
5337 Hi = DAG.getMaskedGather(DAG.getVTList(HiVT, MVT::Other), HiVT, DL, OpsHi,
5340 AddToWorklist(Lo.getNode());
5341 AddToWorklist(Hi.getNode());
5343 // Build a factor node to remember that this load is independent of the
5345 Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Lo.getValue(1),
5348 // Legalized the chain result - switch anything that used the old chain to
5350 DAG.ReplaceAllUsesOfValueWith(SDValue(MGT, 1), Chain);
5352 SDValue GatherRes = DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, Lo, Hi);
5354 SDValue RetOps[] = { GatherRes, Chain };
5355 return DAG.getMergeValues(RetOps, DL);
5358 SDValue DAGCombiner::visitMLOAD(SDNode *N) {
5360 if (Level >= AfterLegalizeTypes)
5363 MaskedLoadSDNode *MLD = dyn_cast<MaskedLoadSDNode>(N);
5364 SDValue Mask = MLD->getMask();
5367 // If the MLOAD result requires splitting and the mask is provided by a
5368 // SETCC, then split both nodes and its operands before legalization. This
5369 // prevents the type legalizer from unrolling SETCC into scalar comparisons
5370 // and enables future optimizations (e.g. min/max pattern matching on X86).
5372 if (Mask.getOpcode() == ISD::SETCC) {
5373 EVT VT = N->getValueType(0);
5375 // Check if any splitting is required.
5376 if (TLI.getTypeAction(*DAG.getContext(), VT) !=
5377 TargetLowering::TypeSplitVector)
5380 SDValue MaskLo, MaskHi, Lo, Hi;
5381 std::tie(MaskLo, MaskHi) = SplitVSETCC(Mask.getNode(), DAG);
5383 SDValue Src0 = MLD->getSrc0();
5384 SDValue Src0Lo, Src0Hi;
5385 std::tie(Src0Lo, Src0Hi) = DAG.SplitVector(Src0, DL);
5388 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(MLD->getValueType(0));
5390 SDValue Chain = MLD->getChain();
5391 SDValue Ptr = MLD->getBasePtr();
5392 EVT MemoryVT = MLD->getMemoryVT();
5393 unsigned Alignment = MLD->getOriginalAlignment();
5395 // if Alignment is equal to the vector size,
5396 // take the half of it for the second part
5397 unsigned SecondHalfAlignment =
5398 (Alignment == MLD->getValueType(0).getSizeInBits()/8) ?
5399 Alignment/2 : Alignment;
5401 EVT LoMemVT, HiMemVT;
5402 std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemoryVT);
5404 MachineMemOperand *MMO = DAG.getMachineFunction().
5405 getMachineMemOperand(MLD->getPointerInfo(),
5406 MachineMemOperand::MOLoad, LoMemVT.getStoreSize(),
5407 Alignment, MLD->getAAInfo(), MLD->getRanges());
5409 Lo = DAG.getMaskedLoad(LoVT, DL, Chain, Ptr, MaskLo, Src0Lo, LoMemVT, MMO,
5412 unsigned IncrementSize = LoMemVT.getSizeInBits()/8;
5413 Ptr = DAG.getNode(ISD::ADD, DL, Ptr.getValueType(), Ptr,
5414 DAG.getConstant(IncrementSize, DL, Ptr.getValueType()));
5416 MMO = DAG.getMachineFunction().
5417 getMachineMemOperand(MLD->getPointerInfo(),
5418 MachineMemOperand::MOLoad, HiMemVT.getStoreSize(),
5419 SecondHalfAlignment, MLD->getAAInfo(), MLD->getRanges());
5421 Hi = DAG.getMaskedLoad(HiVT, DL, Chain, Ptr, MaskHi, Src0Hi, HiMemVT, MMO,
5424 AddToWorklist(Lo.getNode());
5425 AddToWorklist(Hi.getNode());
5427 // Build a factor node to remember that this load is independent of the
5429 Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Lo.getValue(1),
5432 // Legalized the chain result - switch anything that used the old chain to
5434 DAG.ReplaceAllUsesOfValueWith(SDValue(MLD, 1), Chain);
5436 SDValue LoadRes = DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, Lo, Hi);
5438 SDValue RetOps[] = { LoadRes, Chain };
5439 return DAG.getMergeValues(RetOps, DL);
5444 SDValue DAGCombiner::visitVSELECT(SDNode *N) {
5445 SDValue N0 = N->getOperand(0);
5446 SDValue N1 = N->getOperand(1);
5447 SDValue N2 = N->getOperand(2);
5450 // Canonicalize integer abs.
5451 // vselect (setg[te] X, 0), X, -X ->
5452 // vselect (setgt X, -1), X, -X ->
5453 // vselect (setl[te] X, 0), -X, X ->
5454 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
5455 if (N0.getOpcode() == ISD::SETCC) {
5456 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
5457 ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
5459 bool RHSIsAllZeros = ISD::isBuildVectorAllZeros(RHS.getNode());
5461 if (((RHSIsAllZeros && (CC == ISD::SETGT || CC == ISD::SETGE)) ||
5462 (ISD::isBuildVectorAllOnes(RHS.getNode()) && CC == ISD::SETGT)) &&
5463 N1 == LHS && N2.getOpcode() == ISD::SUB && N1 == N2.getOperand(1))
5464 isAbs = ISD::isBuildVectorAllZeros(N2.getOperand(0).getNode());
5465 else if ((RHSIsAllZeros && (CC == ISD::SETLT || CC == ISD::SETLE)) &&
5466 N2 == LHS && N1.getOpcode() == ISD::SUB && N2 == N1.getOperand(1))
5467 isAbs = ISD::isBuildVectorAllZeros(N1.getOperand(0).getNode());
5470 EVT VT = LHS.getValueType();
5471 SDValue Shift = DAG.getNode(
5472 ISD::SRA, DL, VT, LHS,
5473 DAG.getConstant(VT.getScalarType().getSizeInBits() - 1, DL, VT));
5474 SDValue Add = DAG.getNode(ISD::ADD, DL, VT, LHS, Shift);
5475 AddToWorklist(Shift.getNode());
5476 AddToWorklist(Add.getNode());
5477 return DAG.getNode(ISD::XOR, DL, VT, Add, Shift);
5481 if (SimplifySelectOps(N, N1, N2))
5482 return SDValue(N, 0); // Don't revisit N.
5484 // If the VSELECT result requires splitting and the mask is provided by a
5485 // SETCC, then split both nodes and its operands before legalization. This
5486 // prevents the type legalizer from unrolling SETCC into scalar comparisons
5487 // and enables future optimizations (e.g. min/max pattern matching on X86).
5488 if (N0.getOpcode() == ISD::SETCC) {
5489 EVT VT = N->getValueType(0);
5491 // Check if any splitting is required.
5492 if (TLI.getTypeAction(*DAG.getContext(), VT) !=
5493 TargetLowering::TypeSplitVector)
5496 SDValue Lo, Hi, CCLo, CCHi, LL, LH, RL, RH;
5497 std::tie(CCLo, CCHi) = SplitVSETCC(N0.getNode(), DAG);
5498 std::tie(LL, LH) = DAG.SplitVectorOperand(N, 1);
5499 std::tie(RL, RH) = DAG.SplitVectorOperand(N, 2);
5501 Lo = DAG.getNode(N->getOpcode(), DL, LL.getValueType(), CCLo, LL, RL);
5502 Hi = DAG.getNode(N->getOpcode(), DL, LH.getValueType(), CCHi, LH, RH);
5504 // Add the new VSELECT nodes to the work list in case they need to be split
5506 AddToWorklist(Lo.getNode());
5507 AddToWorklist(Hi.getNode());
5509 return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, Lo, Hi);
5512 // Fold (vselect (build_vector all_ones), N1, N2) -> N1
5513 if (ISD::isBuildVectorAllOnes(N0.getNode()))
5515 // Fold (vselect (build_vector all_zeros), N1, N2) -> N2
5516 if (ISD::isBuildVectorAllZeros(N0.getNode()))
5519 // The ConvertSelectToConcatVector function is assuming both the above
5520 // checks for (vselect (build_vector all{ones,zeros) ...) have been made
5522 if (N1.getOpcode() == ISD::CONCAT_VECTORS &&
5523 N2.getOpcode() == ISD::CONCAT_VECTORS &&
5524 ISD::isBuildVectorOfConstantSDNodes(N0.getNode())) {
5525 SDValue CV = ConvertSelectToConcatVector(N, DAG);
5533 SDValue DAGCombiner::visitSELECT_CC(SDNode *N) {
5534 SDValue N0 = N->getOperand(0);
5535 SDValue N1 = N->getOperand(1);
5536 SDValue N2 = N->getOperand(2);
5537 SDValue N3 = N->getOperand(3);
5538 SDValue N4 = N->getOperand(4);
5539 ISD::CondCode CC = cast<CondCodeSDNode>(N4)->get();
5541 // fold select_cc lhs, rhs, x, x, cc -> x
5545 // Determine if the condition we're dealing with is constant
5546 SDValue SCC = SimplifySetCC(getSetCCResultType(N0.getValueType()),
5547 N0, N1, CC, SDLoc(N), false);
5548 if (SCC.getNode()) {
5549 AddToWorklist(SCC.getNode());
5551 if (ConstantSDNode *SCCC = dyn_cast<ConstantSDNode>(SCC.getNode())) {
5552 if (!SCCC->isNullValue())
5553 return N2; // cond always true -> true val
5555 return N3; // cond always false -> false val
5556 } else if (SCC->getOpcode() == ISD::UNDEF) {
5557 // When the condition is UNDEF, just return the first operand. This is
5558 // coherent the DAG creation, no setcc node is created in this case
5560 } else if (SCC.getOpcode() == ISD::SETCC) {
5561 // Fold to a simpler select_cc
5562 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), N2.getValueType(),
5563 SCC.getOperand(0), SCC.getOperand(1), N2, N3,
5568 // If we can fold this based on the true/false value, do so.
5569 if (SimplifySelectOps(N, N2, N3))
5570 return SDValue(N, 0); // Don't revisit N.
5572 // fold select_cc into other things, such as min/max/abs
5573 return SimplifySelectCC(SDLoc(N), N0, N1, N2, N3, CC);
5576 SDValue DAGCombiner::visitSETCC(SDNode *N) {
5577 return SimplifySetCC(N->getValueType(0), N->getOperand(0), N->getOperand(1),
5578 cast<CondCodeSDNode>(N->getOperand(2))->get(),
5582 // tryToFoldExtendOfConstant - Try to fold a sext/zext/aext
5583 // dag node into a ConstantSDNode or a build_vector of constants.
5584 // This function is called by the DAGCombiner when visiting sext/zext/aext
5585 // dag nodes (see for example method DAGCombiner::visitSIGN_EXTEND).
5586 // Vector extends are not folded if operations are legal; this is to
5587 // avoid introducing illegal build_vector dag nodes.
5588 static SDNode *tryToFoldExtendOfConstant(SDNode *N, const TargetLowering &TLI,
5589 SelectionDAG &DAG, bool LegalTypes,
5590 bool LegalOperations) {
5591 unsigned Opcode = N->getOpcode();
5592 SDValue N0 = N->getOperand(0);
5593 EVT VT = N->getValueType(0);
5595 assert((Opcode == ISD::SIGN_EXTEND || Opcode == ISD::ZERO_EXTEND ||
5596 Opcode == ISD::ANY_EXTEND || Opcode == ISD::SIGN_EXTEND_VECTOR_INREG)
5597 && "Expected EXTEND dag node in input!");
5599 // fold (sext c1) -> c1
5600 // fold (zext c1) -> c1
5601 // fold (aext c1) -> c1
5602 if (isa<ConstantSDNode>(N0))
5603 return DAG.getNode(Opcode, SDLoc(N), VT, N0).getNode();
5605 // fold (sext (build_vector AllConstants) -> (build_vector AllConstants)
5606 // fold (zext (build_vector AllConstants) -> (build_vector AllConstants)
5607 // fold (aext (build_vector AllConstants) -> (build_vector AllConstants)
5608 EVT SVT = VT.getScalarType();
5609 if (!(VT.isVector() &&
5610 (!LegalTypes || (!LegalOperations && TLI.isTypeLegal(SVT))) &&
5611 ISD::isBuildVectorOfConstantSDNodes(N0.getNode())))
5614 // We can fold this node into a build_vector.
5615 unsigned VTBits = SVT.getSizeInBits();
5616 unsigned EVTBits = N0->getValueType(0).getScalarType().getSizeInBits();
5617 unsigned ShAmt = VTBits - EVTBits;
5618 SmallVector<SDValue, 8> Elts;
5619 unsigned NumElts = VT.getVectorNumElements();
5622 for (unsigned i=0; i != NumElts; ++i) {
5623 SDValue Op = N0->getOperand(i);
5624 if (Op->getOpcode() == ISD::UNDEF) {
5625 Elts.push_back(DAG.getUNDEF(SVT));
5630 ConstantSDNode *CurrentND = cast<ConstantSDNode>(Op);
5631 const APInt &C = APInt(VTBits, CurrentND->getAPIntValue().getZExtValue());
5632 if (Opcode == ISD::SIGN_EXTEND || Opcode == ISD::SIGN_EXTEND_VECTOR_INREG)
5633 Elts.push_back(DAG.getConstant(C.shl(ShAmt).ashr(ShAmt).getZExtValue(),
5636 Elts.push_back(DAG.getConstant(C.shl(ShAmt).lshr(ShAmt).getZExtValue(),
5640 return DAG.getNode(ISD::BUILD_VECTOR, DL, VT, Elts).getNode();
5643 // ExtendUsesToFormExtLoad - Trying to extend uses of a load to enable this:
5644 // "fold ({s|z|a}ext (load x)) -> ({s|z|a}ext (truncate ({s|z|a}extload x)))"
5645 // transformation. Returns true if extension are possible and the above
5646 // mentioned transformation is profitable.
5647 static bool ExtendUsesToFormExtLoad(SDNode *N, SDValue N0,
5649 SmallVectorImpl<SDNode *> &ExtendNodes,
5650 const TargetLowering &TLI) {
5651 bool HasCopyToRegUses = false;
5652 bool isTruncFree = TLI.isTruncateFree(N->getValueType(0), N0.getValueType());
5653 for (SDNode::use_iterator UI = N0.getNode()->use_begin(),
5654 UE = N0.getNode()->use_end();
5659 if (UI.getUse().getResNo() != N0.getResNo())
5661 // FIXME: Only extend SETCC N, N and SETCC N, c for now.
5662 if (ExtOpc != ISD::ANY_EXTEND && User->getOpcode() == ISD::SETCC) {
5663 ISD::CondCode CC = cast<CondCodeSDNode>(User->getOperand(2))->get();
5664 if (ExtOpc == ISD::ZERO_EXTEND && ISD::isSignedIntSetCC(CC))
5665 // Sign bits will be lost after a zext.
5668 for (unsigned i = 0; i != 2; ++i) {
5669 SDValue UseOp = User->getOperand(i);
5672 if (!isa<ConstantSDNode>(UseOp))
5677 ExtendNodes.push_back(User);
5680 // If truncates aren't free and there are users we can't
5681 // extend, it isn't worthwhile.
5684 // Remember if this value is live-out.
5685 if (User->getOpcode() == ISD::CopyToReg)
5686 HasCopyToRegUses = true;
5689 if (HasCopyToRegUses) {
5690 bool BothLiveOut = false;
5691 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
5693 SDUse &Use = UI.getUse();
5694 if (Use.getResNo() == 0 && Use.getUser()->getOpcode() == ISD::CopyToReg) {
5700 // Both unextended and extended values are live out. There had better be
5701 // a good reason for the transformation.
5702 return ExtendNodes.size();
5707 void DAGCombiner::ExtendSetCCUses(const SmallVectorImpl<SDNode *> &SetCCs,
5708 SDValue Trunc, SDValue ExtLoad, SDLoc DL,
5709 ISD::NodeType ExtType) {
5710 // Extend SetCC uses if necessary.
5711 for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
5712 SDNode *SetCC = SetCCs[i];
5713 SmallVector<SDValue, 4> Ops;
5715 for (unsigned j = 0; j != 2; ++j) {
5716 SDValue SOp = SetCC->getOperand(j);
5718 Ops.push_back(ExtLoad);
5720 Ops.push_back(DAG.getNode(ExtType, DL, ExtLoad->getValueType(0), SOp));
5723 Ops.push_back(SetCC->getOperand(2));
5724 CombineTo(SetCC, DAG.getNode(ISD::SETCC, DL, SetCC->getValueType(0), Ops));
5728 // FIXME: Bring more similar combines here, common to sext/zext (maybe aext?).
5729 SDValue DAGCombiner::CombineExtLoad(SDNode *N) {
5730 SDValue N0 = N->getOperand(0);
5731 EVT DstVT = N->getValueType(0);
5732 EVT SrcVT = N0.getValueType();
5734 assert((N->getOpcode() == ISD::SIGN_EXTEND ||
5735 N->getOpcode() == ISD::ZERO_EXTEND) &&
5736 "Unexpected node type (not an extend)!");
5738 // fold (sext (load x)) to multiple smaller sextloads; same for zext.
5739 // For example, on a target with legal v4i32, but illegal v8i32, turn:
5740 // (v8i32 (sext (v8i16 (load x))))
5742 // (v8i32 (concat_vectors (v4i32 (sextload x)),
5743 // (v4i32 (sextload (x + 16)))))
5744 // Where uses of the original load, i.e.:
5746 // are replaced with:
5748 // (v8i32 (concat_vectors (v4i32 (sextload x)),
5749 // (v4i32 (sextload (x + 16)))))))
5751 // This combine is only applicable to illegal, but splittable, vectors.
5752 // All legal types, and illegal non-vector types, are handled elsewhere.
5753 // This combine is controlled by TargetLowering::isVectorLoadExtDesirable.
5755 if (N0->getOpcode() != ISD::LOAD)
5758 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5760 if (!ISD::isNON_EXTLoad(LN0) || !ISD::isUNINDEXEDLoad(LN0) ||
5761 !N0.hasOneUse() || LN0->isVolatile() || !DstVT.isVector() ||
5762 !DstVT.isPow2VectorType() || !TLI.isVectorLoadExtDesirable(SDValue(N, 0)))
5765 SmallVector<SDNode *, 4> SetCCs;
5766 if (!ExtendUsesToFormExtLoad(N, N0, N->getOpcode(), SetCCs, TLI))
5769 ISD::LoadExtType ExtType =
5770 N->getOpcode() == ISD::SIGN_EXTEND ? ISD::SEXTLOAD : ISD::ZEXTLOAD;
5772 // Try to split the vector types to get down to legal types.
5773 EVT SplitSrcVT = SrcVT;
5774 EVT SplitDstVT = DstVT;
5775 while (!TLI.isLoadExtLegalOrCustom(ExtType, SplitDstVT, SplitSrcVT) &&
5776 SplitSrcVT.getVectorNumElements() > 1) {
5777 SplitDstVT = DAG.GetSplitDestVTs(SplitDstVT).first;
5778 SplitSrcVT = DAG.GetSplitDestVTs(SplitSrcVT).first;
5781 if (!TLI.isLoadExtLegalOrCustom(ExtType, SplitDstVT, SplitSrcVT))
5785 const unsigned NumSplits =
5786 DstVT.getVectorNumElements() / SplitDstVT.getVectorNumElements();
5787 const unsigned Stride = SplitSrcVT.getStoreSize();
5788 SmallVector<SDValue, 4> Loads;
5789 SmallVector<SDValue, 4> Chains;
5791 SDValue BasePtr = LN0->getBasePtr();
5792 for (unsigned Idx = 0; Idx < NumSplits; Idx++) {
5793 const unsigned Offset = Idx * Stride;
5794 const unsigned Align = MinAlign(LN0->getAlignment(), Offset);
5796 SDValue SplitLoad = DAG.getExtLoad(
5797 ExtType, DL, SplitDstVT, LN0->getChain(), BasePtr,
5798 LN0->getPointerInfo().getWithOffset(Offset), SplitSrcVT,
5799 LN0->isVolatile(), LN0->isNonTemporal(), LN0->isInvariant(),
5800 Align, LN0->getAAInfo());
5802 BasePtr = DAG.getNode(ISD::ADD, DL, BasePtr.getValueType(), BasePtr,
5803 DAG.getConstant(Stride, DL, BasePtr.getValueType()));
5805 Loads.push_back(SplitLoad.getValue(0));
5806 Chains.push_back(SplitLoad.getValue(1));
5809 SDValue NewChain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Chains);
5810 SDValue NewValue = DAG.getNode(ISD::CONCAT_VECTORS, DL, DstVT, Loads);
5812 CombineTo(N, NewValue);
5814 // Replace uses of the original load (before extension)
5815 // with a truncate of the concatenated sextloaded vectors.
5817 DAG.getNode(ISD::TRUNCATE, SDLoc(N0), N0.getValueType(), NewValue);
5818 CombineTo(N0.getNode(), Trunc, NewChain);
5819 ExtendSetCCUses(SetCCs, Trunc, NewValue, DL,
5820 (ISD::NodeType)N->getOpcode());
5821 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5824 SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
5825 SDValue N0 = N->getOperand(0);
5826 EVT VT = N->getValueType(0);
5828 if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
5830 return SDValue(Res, 0);
5832 // fold (sext (sext x)) -> (sext x)
5833 // fold (sext (aext x)) -> (sext x)
5834 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
5835 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT,
5838 if (N0.getOpcode() == ISD::TRUNCATE) {
5839 // fold (sext (truncate (load x))) -> (sext (smaller load x))
5840 // fold (sext (truncate (srl (load x), c))) -> (sext (smaller load (x+c/n)))
5841 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
5842 if (NarrowLoad.getNode()) {
5843 SDNode* oye = N0.getNode()->getOperand(0).getNode();
5844 if (NarrowLoad.getNode() != N0.getNode()) {
5845 CombineTo(N0.getNode(), NarrowLoad);
5846 // CombineTo deleted the truncate, if needed, but not what's under it.
5849 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5852 // See if the value being truncated is already sign extended. If so, just
5853 // eliminate the trunc/sext pair.
5854 SDValue Op = N0.getOperand(0);
5855 unsigned OpBits = Op.getValueType().getScalarType().getSizeInBits();
5856 unsigned MidBits = N0.getValueType().getScalarType().getSizeInBits();
5857 unsigned DestBits = VT.getScalarType().getSizeInBits();
5858 unsigned NumSignBits = DAG.ComputeNumSignBits(Op);
5860 if (OpBits == DestBits) {
5861 // Op is i32, Mid is i8, and Dest is i32. If Op has more than 24 sign
5862 // bits, it is already ready.
5863 if (NumSignBits > DestBits-MidBits)
5865 } else if (OpBits < DestBits) {
5866 // Op is i32, Mid is i8, and Dest is i64. If Op has more than 24 sign
5867 // bits, just sext from i32.
5868 if (NumSignBits > OpBits-MidBits)
5869 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, Op);
5871 // Op is i64, Mid is i8, and Dest is i32. If Op has more than 56 sign
5872 // bits, just truncate to i32.
5873 if (NumSignBits > OpBits-MidBits)
5874 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Op);
5877 // fold (sext (truncate x)) -> (sextinreg x).
5878 if (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG,
5879 N0.getValueType())) {
5880 if (OpBits < DestBits)
5881 Op = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N0), VT, Op);
5882 else if (OpBits > DestBits)
5883 Op = DAG.getNode(ISD::TRUNCATE, SDLoc(N0), VT, Op);
5884 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT, Op,
5885 DAG.getValueType(N0.getValueType()));
5889 // fold (sext (load x)) -> (sext (truncate (sextload x)))
5890 // Only generate vector extloads when 1) they're legal, and 2) they are
5891 // deemed desirable by the target.
5892 if (ISD::isNON_EXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
5893 ((!LegalOperations && !VT.isVector() &&
5894 !cast<LoadSDNode>(N0)->isVolatile()) ||
5895 TLI.isLoadExtLegal(ISD::SEXTLOAD, VT, N0.getValueType()))) {
5896 bool DoXform = true;
5897 SmallVector<SDNode*, 4> SetCCs;
5898 if (!N0.hasOneUse())
5899 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::SIGN_EXTEND, SetCCs, TLI);
5901 DoXform &= TLI.isVectorLoadExtDesirable(SDValue(N, 0));
5903 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5904 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
5906 LN0->getBasePtr(), N0.getValueType(),
5907 LN0->getMemOperand());
5908 CombineTo(N, ExtLoad);
5909 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
5910 N0.getValueType(), ExtLoad);
5911 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
5912 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
5914 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5918 // fold (sext (load x)) to multiple smaller sextloads.
5919 // Only on illegal but splittable vectors.
5920 if (SDValue ExtLoad = CombineExtLoad(N))
5923 // fold (sext (sextload x)) -> (sext (truncate (sextload x)))
5924 // fold (sext ( extload x)) -> (sext (truncate (sextload x)))
5925 if ((ISD::isSEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
5926 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
5927 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5928 EVT MemVT = LN0->getMemoryVT();
5929 if ((!LegalOperations && !LN0->isVolatile()) ||
5930 TLI.isLoadExtLegal(ISD::SEXTLOAD, VT, MemVT)) {
5931 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
5933 LN0->getBasePtr(), MemVT,
5934 LN0->getMemOperand());
5935 CombineTo(N, ExtLoad);
5936 CombineTo(N0.getNode(),
5937 DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
5938 N0.getValueType(), ExtLoad),
5939 ExtLoad.getValue(1));
5940 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5944 // fold (sext (and/or/xor (load x), cst)) ->
5945 // (and/or/xor (sextload x), (sext cst))
5946 if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
5947 N0.getOpcode() == ISD::XOR) &&
5948 isa<LoadSDNode>(N0.getOperand(0)) &&
5949 N0.getOperand(1).getOpcode() == ISD::Constant &&
5950 TLI.isLoadExtLegal(ISD::SEXTLOAD, VT, N0.getValueType()) &&
5951 (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
5952 LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
5953 if (LN0->getExtensionType() != ISD::ZEXTLOAD && LN0->isUnindexed()) {
5954 bool DoXform = true;
5955 SmallVector<SDNode*, 4> SetCCs;
5956 if (!N0.hasOneUse())
5957 DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::SIGN_EXTEND,
5960 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(LN0), VT,
5961 LN0->getChain(), LN0->getBasePtr(),
5963 LN0->getMemOperand());
5964 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
5965 Mask = Mask.sext(VT.getSizeInBits());
5967 SDValue And = DAG.getNode(N0.getOpcode(), DL, VT,
5968 ExtLoad, DAG.getConstant(Mask, DL, VT));
5969 SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
5970 SDLoc(N0.getOperand(0)),
5971 N0.getOperand(0).getValueType(), ExtLoad);
5973 CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
5974 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, DL,
5976 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5981 if (N0.getOpcode() == ISD::SETCC) {
5982 EVT N0VT = N0.getOperand(0).getValueType();
5983 // sext(setcc) -> sext_in_reg(vsetcc) for vectors.
5984 // Only do this before legalize for now.
5985 if (VT.isVector() && !LegalOperations &&
5986 TLI.getBooleanContents(N0VT) ==
5987 TargetLowering::ZeroOrNegativeOneBooleanContent) {
5988 // On some architectures (such as SSE/NEON/etc) the SETCC result type is
5989 // of the same size as the compared operands. Only optimize sext(setcc())
5990 // if this is the case.
5991 EVT SVT = getSetCCResultType(N0VT);
5993 // We know that the # elements of the results is the same as the
5994 // # elements of the compare (and the # elements of the compare result
5995 // for that matter). Check to see that they are the same size. If so,
5996 // we know that the element size of the sext'd result matches the
5997 // element size of the compare operands.
5998 if (VT.getSizeInBits() == SVT.getSizeInBits())
5999 return DAG.getSetCC(SDLoc(N), VT, N0.getOperand(0),
6001 cast<CondCodeSDNode>(N0.getOperand(2))->get());
6003 // If the desired elements are smaller or larger than the source
6004 // elements we can use a matching integer vector type and then
6005 // truncate/sign extend
6006 EVT MatchingVectorType = N0VT.changeVectorElementTypeToInteger();
6007 if (SVT == MatchingVectorType) {
6008 SDValue VsetCC = DAG.getSetCC(SDLoc(N), MatchingVectorType,
6009 N0.getOperand(0), N0.getOperand(1),
6010 cast<CondCodeSDNode>(N0.getOperand(2))->get());
6011 return DAG.getSExtOrTrunc(VsetCC, SDLoc(N), VT);
6015 // sext(setcc x, y, cc) -> (select (setcc x, y, cc), -1, 0)
6016 unsigned ElementWidth = VT.getScalarType().getSizeInBits();
6019 DAG.getConstant(APInt::getAllOnesValue(ElementWidth), DL, VT);
6021 SimplifySelectCC(DL, N0.getOperand(0), N0.getOperand(1),
6022 NegOne, DAG.getConstant(0, DL, VT),
6023 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
6024 if (SCC.getNode()) return SCC;
6026 if (!VT.isVector()) {
6027 EVT SetCCVT = getSetCCResultType(N0.getOperand(0).getValueType());
6028 if (!LegalOperations || TLI.isOperationLegal(ISD::SETCC, SetCCVT)) {
6030 ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
6031 SDValue SetCC = DAG.getSetCC(DL, SetCCVT,
6032 N0.getOperand(0), N0.getOperand(1), CC);
6033 return DAG.getSelect(DL, VT, SetCC,
6034 NegOne, DAG.getConstant(0, DL, VT));
6039 // fold (sext x) -> (zext x) if the sign bit is known zero.
6040 if ((!LegalOperations || TLI.isOperationLegal(ISD::ZERO_EXTEND, VT)) &&
6041 DAG.SignBitIsZero(N0))
6042 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, N0);
6047 // isTruncateOf - If N is a truncate of some other value, return true, record
6048 // the value being truncated in Op and which of Op's bits are zero in KnownZero.
6049 // This function computes KnownZero to avoid a duplicated call to
6050 // computeKnownBits in the caller.
6051 static bool isTruncateOf(SelectionDAG &DAG, SDValue N, SDValue &Op,
6054 if (N->getOpcode() == ISD::TRUNCATE) {
6055 Op = N->getOperand(0);
6056 DAG.computeKnownBits(Op, KnownZero, KnownOne);
6060 if (N->getOpcode() != ISD::SETCC || N->getValueType(0) != MVT::i1 ||
6061 cast<CondCodeSDNode>(N->getOperand(2))->get() != ISD::SETNE)
6064 SDValue Op0 = N->getOperand(0);
6065 SDValue Op1 = N->getOperand(1);
6066 assert(Op0.getValueType() == Op1.getValueType());
6068 if (isNullConstant(Op0))
6070 else if (isNullConstant(Op1))
6075 DAG.computeKnownBits(Op, KnownZero, KnownOne);
6077 if (!(KnownZero | APInt(Op.getValueSizeInBits(), 1)).isAllOnesValue())
6083 SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) {
6084 SDValue N0 = N->getOperand(0);
6085 EVT VT = N->getValueType(0);
6087 if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
6089 return SDValue(Res, 0);
6091 // fold (zext (zext x)) -> (zext x)
6092 // fold (zext (aext x)) -> (zext x)
6093 if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
6094 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT,
6097 // fold (zext (truncate x)) -> (zext x) or
6098 // (zext (truncate x)) -> (truncate x)
6099 // This is valid when the truncated bits of x are already zero.
6100 // FIXME: We should extend this to work for vectors too.
6103 if (!VT.isVector() && isTruncateOf(DAG, N0, Op, KnownZero)) {
6104 APInt TruncatedBits =
6105 (Op.getValueSizeInBits() == N0.getValueSizeInBits()) ?
6106 APInt(Op.getValueSizeInBits(), 0) :
6107 APInt::getBitsSet(Op.getValueSizeInBits(),
6108 N0.getValueSizeInBits(),
6109 std::min(Op.getValueSizeInBits(),
6110 VT.getSizeInBits()));
6111 if (TruncatedBits == (KnownZero & TruncatedBits)) {
6112 if (VT.bitsGT(Op.getValueType()))
6113 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, Op);
6114 if (VT.bitsLT(Op.getValueType()))
6115 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Op);
6121 // fold (zext (truncate (load x))) -> (zext (smaller load x))
6122 // fold (zext (truncate (srl (load x), c))) -> (zext (small load (x+c/n)))
6123 if (N0.getOpcode() == ISD::TRUNCATE) {
6124 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
6125 if (NarrowLoad.getNode()) {
6126 SDNode* oye = N0.getNode()->getOperand(0).getNode();
6127 if (NarrowLoad.getNode() != N0.getNode()) {
6128 CombineTo(N0.getNode(), NarrowLoad);
6129 // CombineTo deleted the truncate, if needed, but not what's under it.
6132 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6136 // fold (zext (truncate x)) -> (and x, mask)
6137 if (N0.getOpcode() == ISD::TRUNCATE &&
6138 (!LegalOperations || TLI.isOperationLegal(ISD::AND, VT))) {
6140 // fold (zext (truncate (load x))) -> (zext (smaller load x))
6141 // fold (zext (truncate (srl (load x), c))) -> (zext (smaller load (x+c/n)))
6142 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
6143 if (NarrowLoad.getNode()) {
6144 SDNode* oye = N0.getNode()->getOperand(0).getNode();
6145 if (NarrowLoad.getNode() != N0.getNode()) {
6146 CombineTo(N0.getNode(), NarrowLoad);
6147 // CombineTo deleted the truncate, if needed, but not what's under it.
6150 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6153 SDValue Op = N0.getOperand(0);
6154 if (Op.getValueType().bitsLT(VT)) {
6155 Op = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, Op);
6156 AddToWorklist(Op.getNode());
6157 } else if (Op.getValueType().bitsGT(VT)) {
6158 Op = DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Op);
6159 AddToWorklist(Op.getNode());
6161 return DAG.getZeroExtendInReg(Op, SDLoc(N),
6162 N0.getValueType().getScalarType());
6165 // Fold (zext (and (trunc x), cst)) -> (and x, cst),
6166 // if either of the casts is not free.
6167 if (N0.getOpcode() == ISD::AND &&
6168 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
6169 N0.getOperand(1).getOpcode() == ISD::Constant &&
6170 (!TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
6171 N0.getValueType()) ||
6172 !TLI.isZExtFree(N0.getValueType(), VT))) {
6173 SDValue X = N0.getOperand(0).getOperand(0);
6174 if (X.getValueType().bitsLT(VT)) {
6175 X = DAG.getNode(ISD::ANY_EXTEND, SDLoc(X), VT, X);
6176 } else if (X.getValueType().bitsGT(VT)) {
6177 X = DAG.getNode(ISD::TRUNCATE, SDLoc(X), VT, X);
6179 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
6180 Mask = Mask.zext(VT.getSizeInBits());
6182 return DAG.getNode(ISD::AND, DL, VT,
6183 X, DAG.getConstant(Mask, DL, VT));
6186 // fold (zext (load x)) -> (zext (truncate (zextload x)))
6187 // Only generate vector extloads when 1) they're legal, and 2) they are
6188 // deemed desirable by the target.
6189 if (ISD::isNON_EXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
6190 ((!LegalOperations && !VT.isVector() &&
6191 !cast<LoadSDNode>(N0)->isVolatile()) ||
6192 TLI.isLoadExtLegal(ISD::ZEXTLOAD, VT, N0.getValueType()))) {
6193 bool DoXform = true;
6194 SmallVector<SDNode*, 4> SetCCs;
6195 if (!N0.hasOneUse())
6196 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ZERO_EXTEND, SetCCs, TLI);
6198 DoXform &= TLI.isVectorLoadExtDesirable(SDValue(N, 0));
6200 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6201 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N), VT,
6203 LN0->getBasePtr(), N0.getValueType(),
6204 LN0->getMemOperand());
6205 CombineTo(N, ExtLoad);
6206 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
6207 N0.getValueType(), ExtLoad);
6208 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
6210 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
6212 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6216 // fold (zext (load x)) to multiple smaller zextloads.
6217 // Only on illegal but splittable vectors.
6218 if (SDValue ExtLoad = CombineExtLoad(N))
6221 // fold (zext (and/or/xor (load x), cst)) ->
6222 // (and/or/xor (zextload x), (zext cst))
6223 if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
6224 N0.getOpcode() == ISD::XOR) &&
6225 isa<LoadSDNode>(N0.getOperand(0)) &&
6226 N0.getOperand(1).getOpcode() == ISD::Constant &&
6227 TLI.isLoadExtLegal(ISD::ZEXTLOAD, VT, N0.getValueType()) &&
6228 (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
6229 LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
6230 if (LN0->getExtensionType() != ISD::SEXTLOAD && LN0->isUnindexed()) {
6231 bool DoXform = true;
6232 SmallVector<SDNode*, 4> SetCCs;
6233 if (!N0.hasOneUse())
6234 DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::ZERO_EXTEND,
6237 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), VT,
6238 LN0->getChain(), LN0->getBasePtr(),
6240 LN0->getMemOperand());
6241 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
6242 Mask = Mask.zext(VT.getSizeInBits());
6244 SDValue And = DAG.getNode(N0.getOpcode(), DL, VT,
6245 ExtLoad, DAG.getConstant(Mask, DL, VT));
6246 SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
6247 SDLoc(N0.getOperand(0)),
6248 N0.getOperand(0).getValueType(), ExtLoad);
6250 CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
6251 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, DL,
6253 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6258 // fold (zext (zextload x)) -> (zext (truncate (zextload x)))
6259 // fold (zext ( extload x)) -> (zext (truncate (zextload x)))
6260 if ((ISD::isZEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
6261 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
6262 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6263 EVT MemVT = LN0->getMemoryVT();
6264 if ((!LegalOperations && !LN0->isVolatile()) ||
6265 TLI.isLoadExtLegal(ISD::ZEXTLOAD, VT, MemVT)) {
6266 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N), VT,
6268 LN0->getBasePtr(), MemVT,
6269 LN0->getMemOperand());
6270 CombineTo(N, ExtLoad);
6271 CombineTo(N0.getNode(),
6272 DAG.getNode(ISD::TRUNCATE, SDLoc(N0), N0.getValueType(),
6274 ExtLoad.getValue(1));
6275 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6279 if (N0.getOpcode() == ISD::SETCC) {
6280 if (!LegalOperations && VT.isVector() &&
6281 N0.getValueType().getVectorElementType() == MVT::i1) {
6282 EVT N0VT = N0.getOperand(0).getValueType();
6283 if (getSetCCResultType(N0VT) == N0.getValueType())
6286 // zext(setcc) -> (and (vsetcc), (1, 1, ...) for vectors.
6287 // Only do this before legalize for now.
6288 EVT EltVT = VT.getVectorElementType();
6290 SmallVector<SDValue,8> OneOps(VT.getVectorNumElements(),
6291 DAG.getConstant(1, DL, EltVT));
6292 if (VT.getSizeInBits() == N0VT.getSizeInBits())
6293 // We know that the # elements of the results is the same as the
6294 // # elements of the compare (and the # elements of the compare result
6295 // for that matter). Check to see that they are the same size. If so,
6296 // we know that the element size of the sext'd result matches the
6297 // element size of the compare operands.
6298 return DAG.getNode(ISD::AND, DL, VT,
6299 DAG.getSetCC(DL, VT, N0.getOperand(0),
6301 cast<CondCodeSDNode>(N0.getOperand(2))->get()),
6302 DAG.getNode(ISD::BUILD_VECTOR, DL, VT,
6305 // If the desired elements are smaller or larger than the source
6306 // elements we can use a matching integer vector type and then
6307 // truncate/sign extend
6308 EVT MatchingElementType =
6309 EVT::getIntegerVT(*DAG.getContext(),
6310 N0VT.getScalarType().getSizeInBits());
6311 EVT MatchingVectorType =
6312 EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
6313 N0VT.getVectorNumElements());
6315 DAG.getSetCC(DL, MatchingVectorType, N0.getOperand(0),
6317 cast<CondCodeSDNode>(N0.getOperand(2))->get());
6318 return DAG.getNode(ISD::AND, DL, VT,
6319 DAG.getSExtOrTrunc(VsetCC, DL, VT),
6320 DAG.getNode(ISD::BUILD_VECTOR, DL, VT, OneOps));
6323 // zext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
6326 SimplifySelectCC(DL, N0.getOperand(0), N0.getOperand(1),
6327 DAG.getConstant(1, DL, VT), DAG.getConstant(0, DL, VT),
6328 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
6329 if (SCC.getNode()) return SCC;
6332 // (zext (shl (zext x), cst)) -> (shl (zext x), cst)
6333 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL) &&
6334 isa<ConstantSDNode>(N0.getOperand(1)) &&
6335 N0.getOperand(0).getOpcode() == ISD::ZERO_EXTEND &&
6337 SDValue ShAmt = N0.getOperand(1);
6338 unsigned ShAmtVal = cast<ConstantSDNode>(ShAmt)->getZExtValue();
6339 if (N0.getOpcode() == ISD::SHL) {
6340 SDValue InnerZExt = N0.getOperand(0);
6341 // If the original shl may be shifting out bits, do not perform this
6343 unsigned KnownZeroBits = InnerZExt.getValueType().getSizeInBits() -
6344 InnerZExt.getOperand(0).getValueType().getSizeInBits();
6345 if (ShAmtVal > KnownZeroBits)
6351 // Ensure that the shift amount is wide enough for the shifted value.
6352 if (VT.getSizeInBits() >= 256)
6353 ShAmt = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, ShAmt);
6355 return DAG.getNode(N0.getOpcode(), DL, VT,
6356 DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0)),
6363 SDValue DAGCombiner::visitANY_EXTEND(SDNode *N) {
6364 SDValue N0 = N->getOperand(0);
6365 EVT VT = N->getValueType(0);
6367 if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
6369 return SDValue(Res, 0);
6371 // fold (aext (aext x)) -> (aext x)
6372 // fold (aext (zext x)) -> (zext x)
6373 // fold (aext (sext x)) -> (sext x)
6374 if (N0.getOpcode() == ISD::ANY_EXTEND ||
6375 N0.getOpcode() == ISD::ZERO_EXTEND ||
6376 N0.getOpcode() == ISD::SIGN_EXTEND)
6377 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT, N0.getOperand(0));
6379 // fold (aext (truncate (load x))) -> (aext (smaller load x))
6380 // fold (aext (truncate (srl (load x), c))) -> (aext (small load (x+c/n)))
6381 if (N0.getOpcode() == ISD::TRUNCATE) {
6382 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
6383 if (NarrowLoad.getNode()) {
6384 SDNode* oye = N0.getNode()->getOperand(0).getNode();
6385 if (NarrowLoad.getNode() != N0.getNode()) {
6386 CombineTo(N0.getNode(), NarrowLoad);
6387 // CombineTo deleted the truncate, if needed, but not what's under it.
6390 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6394 // fold (aext (truncate x))
6395 if (N0.getOpcode() == ISD::TRUNCATE) {
6396 SDValue TruncOp = N0.getOperand(0);
6397 if (TruncOp.getValueType() == VT)
6398 return TruncOp; // x iff x size == zext size.
6399 if (TruncOp.getValueType().bitsGT(VT))
6400 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, TruncOp);
6401 return DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, TruncOp);
6404 // Fold (aext (and (trunc x), cst)) -> (and x, cst)
6405 // if the trunc is not free.
6406 if (N0.getOpcode() == ISD::AND &&
6407 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
6408 N0.getOperand(1).getOpcode() == ISD::Constant &&
6409 !TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
6410 N0.getValueType())) {
6411 SDValue X = N0.getOperand(0).getOperand(0);
6412 if (X.getValueType().bitsLT(VT)) {
6413 X = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, X);
6414 } else if (X.getValueType().bitsGT(VT)) {
6415 X = DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, X);
6417 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
6418 Mask = Mask.zext(VT.getSizeInBits());
6420 return DAG.getNode(ISD::AND, DL, VT,
6421 X, DAG.getConstant(Mask, DL, VT));
6424 // fold (aext (load x)) -> (aext (truncate (extload x)))
6425 // None of the supported targets knows how to perform load and any_ext
6426 // on vectors in one instruction. We only perform this transformation on
6428 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
6429 ISD::isUNINDEXEDLoad(N0.getNode()) &&
6430 TLI.isLoadExtLegal(ISD::EXTLOAD, VT, N0.getValueType())) {
6431 bool DoXform = true;
6432 SmallVector<SDNode*, 4> SetCCs;
6433 if (!N0.hasOneUse())
6434 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ANY_EXTEND, SetCCs, TLI);
6436 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6437 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, SDLoc(N), VT,
6439 LN0->getBasePtr(), N0.getValueType(),
6440 LN0->getMemOperand());
6441 CombineTo(N, ExtLoad);
6442 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
6443 N0.getValueType(), ExtLoad);
6444 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
6445 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
6447 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6451 // fold (aext (zextload x)) -> (aext (truncate (zextload x)))
6452 // fold (aext (sextload x)) -> (aext (truncate (sextload x)))
6453 // fold (aext ( extload x)) -> (aext (truncate (extload x)))
6454 if (N0.getOpcode() == ISD::LOAD &&
6455 !ISD::isNON_EXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
6457 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6458 ISD::LoadExtType ExtType = LN0->getExtensionType();
6459 EVT MemVT = LN0->getMemoryVT();
6460 if (!LegalOperations || TLI.isLoadExtLegal(ExtType, VT, MemVT)) {
6461 SDValue ExtLoad = DAG.getExtLoad(ExtType, SDLoc(N),
6462 VT, LN0->getChain(), LN0->getBasePtr(),
6463 MemVT, LN0->getMemOperand());
6464 CombineTo(N, ExtLoad);
6465 CombineTo(N0.getNode(),
6466 DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
6467 N0.getValueType(), ExtLoad),
6468 ExtLoad.getValue(1));
6469 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6473 if (N0.getOpcode() == ISD::SETCC) {
6475 // aext(setcc) -> vsetcc
6476 // aext(setcc) -> truncate(vsetcc)
6477 // aext(setcc) -> aext(vsetcc)
6478 // Only do this before legalize for now.
6479 if (VT.isVector() && !LegalOperations) {
6480 EVT N0VT = N0.getOperand(0).getValueType();
6481 // We know that the # elements of the results is the same as the
6482 // # elements of the compare (and the # elements of the compare result
6483 // for that matter). Check to see that they are the same size. If so,
6484 // we know that the element size of the sext'd result matches the
6485 // element size of the compare operands.
6486 if (VT.getSizeInBits() == N0VT.getSizeInBits())
6487 return DAG.getSetCC(SDLoc(N), VT, N0.getOperand(0),
6489 cast<CondCodeSDNode>(N0.getOperand(2))->get());
6490 // If the desired elements are smaller or larger than the source
6491 // elements we can use a matching integer vector type and then
6492 // truncate/any extend
6494 EVT MatchingVectorType = N0VT.changeVectorElementTypeToInteger();
6496 DAG.getSetCC(SDLoc(N), MatchingVectorType, N0.getOperand(0),
6498 cast<CondCodeSDNode>(N0.getOperand(2))->get());
6499 return DAG.getAnyExtOrTrunc(VsetCC, SDLoc(N), VT);
6503 // aext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
6506 SimplifySelectCC(DL, N0.getOperand(0), N0.getOperand(1),
6507 DAG.getConstant(1, DL, VT), DAG.getConstant(0, DL, VT),
6508 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
6516 /// See if the specified operand can be simplified with the knowledge that only
6517 /// the bits specified by Mask are used. If so, return the simpler operand,
6518 /// otherwise return a null SDValue.
6519 SDValue DAGCombiner::GetDemandedBits(SDValue V, const APInt &Mask) {
6520 switch (V.getOpcode()) {
6522 case ISD::Constant: {
6523 const ConstantSDNode *CV = cast<ConstantSDNode>(V.getNode());
6524 assert(CV && "Const value should be ConstSDNode.");
6525 const APInt &CVal = CV->getAPIntValue();
6526 APInt NewVal = CVal & Mask;
6528 return DAG.getConstant(NewVal, SDLoc(V), V.getValueType());
6533 // If the LHS or RHS don't contribute bits to the or, drop them.
6534 if (DAG.MaskedValueIsZero(V.getOperand(0), Mask))
6535 return V.getOperand(1);
6536 if (DAG.MaskedValueIsZero(V.getOperand(1), Mask))
6537 return V.getOperand(0);
6540 // Only look at single-use SRLs.
6541 if (!V.getNode()->hasOneUse())
6543 if (ConstantSDNode *RHSC = getAsNonOpaqueConstant(V.getOperand(1))) {
6544 // See if we can recursively simplify the LHS.
6545 unsigned Amt = RHSC->getZExtValue();
6547 // Watch out for shift count overflow though.
6548 if (Amt >= Mask.getBitWidth()) break;
6549 APInt NewMask = Mask << Amt;
6550 SDValue SimplifyLHS = GetDemandedBits(V.getOperand(0), NewMask);
6551 if (SimplifyLHS.getNode())
6552 return DAG.getNode(ISD::SRL, SDLoc(V), V.getValueType(),
6553 SimplifyLHS, V.getOperand(1));
6559 /// If the result of a wider load is shifted to right of N bits and then
6560 /// truncated to a narrower type and where N is a multiple of number of bits of
6561 /// the narrower type, transform it to a narrower load from address + N / num of
6562 /// bits of new type. If the result is to be extended, also fold the extension
6563 /// to form a extending load.
6564 SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) {
6565 unsigned Opc = N->getOpcode();
6567 ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
6568 SDValue N0 = N->getOperand(0);
6569 EVT VT = N->getValueType(0);
6572 // This transformation isn't valid for vector loads.
6576 // Special case: SIGN_EXTEND_INREG is basically truncating to ExtVT then
6578 if (Opc == ISD::SIGN_EXTEND_INREG) {
6579 ExtType = ISD::SEXTLOAD;
6580 ExtVT = cast<VTSDNode>(N->getOperand(1))->getVT();
6581 } else if (Opc == ISD::SRL) {
6582 // Another special-case: SRL is basically zero-extending a narrower value.
6583 ExtType = ISD::ZEXTLOAD;
6585 ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1));
6586 if (!N01) return SDValue();
6587 ExtVT = EVT::getIntegerVT(*DAG.getContext(),
6588 VT.getSizeInBits() - N01->getZExtValue());
6590 if (LegalOperations && !TLI.isLoadExtLegal(ExtType, VT, ExtVT))
6593 unsigned EVTBits = ExtVT.getSizeInBits();
6595 // Do not generate loads of non-round integer types since these can
6596 // be expensive (and would be wrong if the type is not byte sized).
6597 if (!ExtVT.isRound())
6601 if (N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
6602 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
6603 ShAmt = N01->getZExtValue();
6604 // Is the shift amount a multiple of size of VT?
6605 if ((ShAmt & (EVTBits-1)) == 0) {
6606 N0 = N0.getOperand(0);
6607 // Is the load width a multiple of size of VT?
6608 if ((N0.getValueType().getSizeInBits() & (EVTBits-1)) != 0)
6612 // At this point, we must have a load or else we can't do the transform.
6613 if (!isa<LoadSDNode>(N0)) return SDValue();
6615 // Because a SRL must be assumed to *need* to zero-extend the high bits
6616 // (as opposed to anyext the high bits), we can't combine the zextload
6617 // lowering of SRL and an sextload.
6618 if (cast<LoadSDNode>(N0)->getExtensionType() == ISD::SEXTLOAD)
6621 // If the shift amount is larger than the input type then we're not
6622 // accessing any of the loaded bytes. If the load was a zextload/extload
6623 // then the result of the shift+trunc is zero/undef (handled elsewhere).
6624 if (ShAmt >= cast<LoadSDNode>(N0)->getMemoryVT().getSizeInBits())
6629 // If the load is shifted left (and the result isn't shifted back right),
6630 // we can fold the truncate through the shift.
6631 unsigned ShLeftAmt = 0;
6632 if (ShAmt == 0 && N0.getOpcode() == ISD::SHL && N0.hasOneUse() &&
6633 ExtVT == VT && TLI.isNarrowingProfitable(N0.getValueType(), VT)) {
6634 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
6635 ShLeftAmt = N01->getZExtValue();
6636 N0 = N0.getOperand(0);
6640 // If we haven't found a load, we can't narrow it. Don't transform one with
6641 // multiple uses, this would require adding a new load.
6642 if (!isa<LoadSDNode>(N0) || !N0.hasOneUse())
6645 // Don't change the width of a volatile load.
6646 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6647 if (LN0->isVolatile())
6650 // Verify that we are actually reducing a load width here.
6651 if (LN0->getMemoryVT().getSizeInBits() < EVTBits)
6654 // For the transform to be legal, the load must produce only two values
6655 // (the value loaded and the chain). Don't transform a pre-increment
6656 // load, for example, which produces an extra value. Otherwise the
6657 // transformation is not equivalent, and the downstream logic to replace
6658 // uses gets things wrong.
6659 if (LN0->getNumValues() > 2)
6662 // If the load that we're shrinking is an extload and we're not just
6663 // discarding the extension we can't simply shrink the load. Bail.
6664 // TODO: It would be possible to merge the extensions in some cases.
6665 if (LN0->getExtensionType() != ISD::NON_EXTLOAD &&
6666 LN0->getMemoryVT().getSizeInBits() < ExtVT.getSizeInBits() + ShAmt)
6669 if (!TLI.shouldReduceLoadWidth(LN0, ExtType, ExtVT))
6672 EVT PtrType = N0.getOperand(1).getValueType();
6674 if (PtrType == MVT::Untyped || PtrType.isExtended())
6675 // It's not possible to generate a constant of extended or untyped type.
6678 // For big endian targets, we need to adjust the offset to the pointer to
6679 // load the correct bytes.
6680 if (TLI.isBigEndian()) {
6681 unsigned LVTStoreBits = LN0->getMemoryVT().getStoreSizeInBits();
6682 unsigned EVTStoreBits = ExtVT.getStoreSizeInBits();
6683 ShAmt = LVTStoreBits - EVTStoreBits - ShAmt;
6686 uint64_t PtrOff = ShAmt / 8;
6687 unsigned NewAlign = MinAlign(LN0->getAlignment(), PtrOff);
6689 SDValue NewPtr = DAG.getNode(ISD::ADD, DL,
6690 PtrType, LN0->getBasePtr(),
6691 DAG.getConstant(PtrOff, DL, PtrType));
6692 AddToWorklist(NewPtr.getNode());
6695 if (ExtType == ISD::NON_EXTLOAD)
6696 Load = DAG.getLoad(VT, SDLoc(N0), LN0->getChain(), NewPtr,
6697 LN0->getPointerInfo().getWithOffset(PtrOff),
6698 LN0->isVolatile(), LN0->isNonTemporal(),
6699 LN0->isInvariant(), NewAlign, LN0->getAAInfo());
6701 Load = DAG.getExtLoad(ExtType, SDLoc(N0), VT, LN0->getChain(),NewPtr,
6702 LN0->getPointerInfo().getWithOffset(PtrOff),
6703 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
6704 LN0->isInvariant(), NewAlign, LN0->getAAInfo());
6706 // Replace the old load's chain with the new load's chain.
6707 WorklistRemover DeadNodes(*this);
6708 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));
6710 // Shift the result left, if we've swallowed a left shift.
6711 SDValue Result = Load;
6712 if (ShLeftAmt != 0) {
6713 EVT ShImmTy = getShiftAmountTy(Result.getValueType());
6714 if (!isUIntN(ShImmTy.getSizeInBits(), ShLeftAmt))
6716 // If the shift amount is as large as the result size (but, presumably,
6717 // no larger than the source) then the useful bits of the result are
6718 // zero; we can't simply return the shortened shift, because the result
6719 // of that operation is undefined.
6721 if (ShLeftAmt >= VT.getSizeInBits())
6722 Result = DAG.getConstant(0, DL, VT);
6724 Result = DAG.getNode(ISD::SHL, DL, VT,
6725 Result, DAG.getConstant(ShLeftAmt, DL, ShImmTy));
6728 // Return the new loaded value.
6732 SDValue DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
6733 SDValue N0 = N->getOperand(0);
6734 SDValue N1 = N->getOperand(1);
6735 EVT VT = N->getValueType(0);
6736 EVT EVT = cast<VTSDNode>(N1)->getVT();
6737 unsigned VTBits = VT.getScalarType().getSizeInBits();
6738 unsigned EVTBits = EVT.getScalarType().getSizeInBits();
6740 // fold (sext_in_reg c1) -> c1
6741 if (isa<ConstantSDNode>(N0) || N0.getOpcode() == ISD::UNDEF)
6742 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT, N0, N1);
6744 // If the input is already sign extended, just drop the extension.
6745 if (DAG.ComputeNumSignBits(N0) >= VTBits-EVTBits+1)
6748 // fold (sext_in_reg (sext_in_reg x, VT2), VT1) -> (sext_in_reg x, minVT) pt2
6749 if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
6750 EVT.bitsLT(cast<VTSDNode>(N0.getOperand(1))->getVT()))
6751 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
6752 N0.getOperand(0), N1);
6754 // fold (sext_in_reg (sext x)) -> (sext x)
6755 // fold (sext_in_reg (aext x)) -> (sext x)
6756 // if x is small enough.
6757 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND) {
6758 SDValue N00 = N0.getOperand(0);
6759 if (N00.getValueType().getScalarType().getSizeInBits() <= EVTBits &&
6760 (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND, VT)))
6761 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, N00, N1);
6764 // fold (sext_in_reg x) -> (zext_in_reg x) if the sign bit is known zero.
6765 if (DAG.MaskedValueIsZero(N0, APInt::getBitsSet(VTBits, EVTBits-1, EVTBits)))
6766 return DAG.getZeroExtendInReg(N0, SDLoc(N), EVT);
6768 // fold operands of sext_in_reg based on knowledge that the top bits are not
6770 if (SimplifyDemandedBits(SDValue(N, 0)))
6771 return SDValue(N, 0);
6773 // fold (sext_in_reg (load x)) -> (smaller sextload x)
6774 // fold (sext_in_reg (srl (load x), c)) -> (smaller sextload (x+c/evtbits))
6775 SDValue NarrowLoad = ReduceLoadWidth(N);
6776 if (NarrowLoad.getNode())
6779 // fold (sext_in_reg (srl X, 24), i8) -> (sra X, 24)
6780 // fold (sext_in_reg (srl X, 23), i8) -> (sra X, 23) iff possible.
6781 // We already fold "(sext_in_reg (srl X, 25), i8) -> srl X, 25" above.
6782 if (N0.getOpcode() == ISD::SRL) {
6783 if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
6784 if (ShAmt->getZExtValue()+EVTBits <= VTBits) {
6785 // We can turn this into an SRA iff the input to the SRL is already sign
6787 unsigned InSignBits = DAG.ComputeNumSignBits(N0.getOperand(0));
6788 if (VTBits-(ShAmt->getZExtValue()+EVTBits) < InSignBits)
6789 return DAG.getNode(ISD::SRA, SDLoc(N), VT,
6790 N0.getOperand(0), N0.getOperand(1));
6794 // fold (sext_inreg (extload x)) -> (sextload x)
6795 if (ISD::isEXTLoad(N0.getNode()) &&
6796 ISD::isUNINDEXEDLoad(N0.getNode()) &&
6797 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
6798 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
6799 TLI.isLoadExtLegal(ISD::SEXTLOAD, VT, EVT))) {
6800 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6801 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
6803 LN0->getBasePtr(), EVT,
6804 LN0->getMemOperand());
6805 CombineTo(N, ExtLoad);
6806 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
6807 AddToWorklist(ExtLoad.getNode());
6808 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6810 // fold (sext_inreg (zextload x)) -> (sextload x) iff load has one use
6811 if (ISD::isZEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
6813 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
6814 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
6815 TLI.isLoadExtLegal(ISD::SEXTLOAD, VT, EVT))) {
6816 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6817 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
6819 LN0->getBasePtr(), EVT,
6820 LN0->getMemOperand());
6821 CombineTo(N, ExtLoad);
6822 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
6823 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6826 // Form (sext_inreg (bswap >> 16)) or (sext_inreg (rotl (bswap) 16))
6827 if (EVTBits <= 16 && N0.getOpcode() == ISD::OR) {
6828 SDValue BSwap = MatchBSwapHWordLow(N0.getNode(), N0.getOperand(0),
6829 N0.getOperand(1), false);
6830 if (BSwap.getNode())
6831 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
6835 // Fold a sext_inreg of a build_vector of ConstantSDNodes or undefs
6836 // into a build_vector.
6837 if (ISD::isBuildVectorOfConstantSDNodes(N0.getNode())) {
6838 SmallVector<SDValue, 8> Elts;
6839 unsigned NumElts = N0->getNumOperands();
6840 unsigned ShAmt = VTBits - EVTBits;
6842 for (unsigned i = 0; i != NumElts; ++i) {
6843 SDValue Op = N0->getOperand(i);
6844 if (Op->getOpcode() == ISD::UNDEF) {
6849 ConstantSDNode *CurrentND = cast<ConstantSDNode>(Op);
6850 const APInt &C = APInt(VTBits, CurrentND->getAPIntValue().getZExtValue());
6851 Elts.push_back(DAG.getConstant(C.shl(ShAmt).ashr(ShAmt).getZExtValue(),
6852 SDLoc(Op), Op.getValueType()));
6855 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, Elts);
6861 SDValue DAGCombiner::visitSIGN_EXTEND_VECTOR_INREG(SDNode *N) {
6862 SDValue N0 = N->getOperand(0);
6863 EVT VT = N->getValueType(0);
6865 if (N0.getOpcode() == ISD::UNDEF)
6866 return DAG.getUNDEF(VT);
6868 if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
6870 return SDValue(Res, 0);
6875 SDValue DAGCombiner::visitTRUNCATE(SDNode *N) {
6876 SDValue N0 = N->getOperand(0);
6877 EVT VT = N->getValueType(0);
6878 bool isLE = TLI.isLittleEndian();
6881 if (N0.getValueType() == N->getValueType(0))
6883 // fold (truncate c1) -> c1
6884 if (isConstantIntBuildVectorOrConstantInt(N0))
6885 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0);
6886 // fold (truncate (truncate x)) -> (truncate x)
6887 if (N0.getOpcode() == ISD::TRUNCATE)
6888 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0.getOperand(0));
6889 // fold (truncate (ext x)) -> (ext x) or (truncate x) or x
6890 if (N0.getOpcode() == ISD::ZERO_EXTEND ||
6891 N0.getOpcode() == ISD::SIGN_EXTEND ||
6892 N0.getOpcode() == ISD::ANY_EXTEND) {
6893 if (N0.getOperand(0).getValueType().bitsLT(VT))
6894 // if the source is smaller than the dest, we still need an extend
6895 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
6897 if (N0.getOperand(0).getValueType().bitsGT(VT))
6898 // if the source is larger than the dest, than we just need the truncate
6899 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0.getOperand(0));
6900 // if the source and dest are the same type, we can drop both the extend
6901 // and the truncate.
6902 return N0.getOperand(0);
6905 // Fold extract-and-trunc into a narrow extract. For example:
6906 // i64 x = EXTRACT_VECTOR_ELT(v2i64 val, i32 1)
6907 // i32 y = TRUNCATE(i64 x)
6909 // v16i8 b = BITCAST (v2i64 val)
6910 // i8 x = EXTRACT_VECTOR_ELT(v16i8 b, i32 8)
6912 // Note: We only run this optimization after type legalization (which often
6913 // creates this pattern) and before operation legalization after which
6914 // we need to be more careful about the vector instructions that we generate.
6915 if (N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
6916 LegalTypes && !LegalOperations && N0->hasOneUse() && VT != MVT::i1) {
6918 EVT VecTy = N0.getOperand(0).getValueType();
6919 EVT ExTy = N0.getValueType();
6920 EVT TrTy = N->getValueType(0);
6922 unsigned NumElem = VecTy.getVectorNumElements();
6923 unsigned SizeRatio = ExTy.getSizeInBits()/TrTy.getSizeInBits();
6925 EVT NVT = EVT::getVectorVT(*DAG.getContext(), TrTy, SizeRatio * NumElem);
6926 assert(NVT.getSizeInBits() == VecTy.getSizeInBits() && "Invalid Size");
6928 SDValue EltNo = N0->getOperand(1);
6929 if (isa<ConstantSDNode>(EltNo) && isTypeLegal(NVT)) {
6930 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
6931 EVT IndexTy = TLI.getVectorIdxTy();
6932 int Index = isLE ? (Elt*SizeRatio) : (Elt*SizeRatio + (SizeRatio-1));
6934 SDValue V = DAG.getNode(ISD::BITCAST, SDLoc(N),
6935 NVT, N0.getOperand(0));
6938 return DAG.getNode(ISD::EXTRACT_VECTOR_ELT,
6940 DAG.getConstant(Index, DL, IndexTy));
6944 // trunc (select c, a, b) -> select c, (trunc a), (trunc b)
6945 if (N0.getOpcode() == ISD::SELECT) {
6946 EVT SrcVT = N0.getValueType();
6947 if ((!LegalOperations || TLI.isOperationLegal(ISD::SELECT, SrcVT)) &&
6948 TLI.isTruncateFree(SrcVT, VT)) {
6950 SDValue Cond = N0.getOperand(0);
6951 SDValue TruncOp0 = DAG.getNode(ISD::TRUNCATE, SL, VT, N0.getOperand(1));
6952 SDValue TruncOp1 = DAG.getNode(ISD::TRUNCATE, SL, VT, N0.getOperand(2));
6953 return DAG.getNode(ISD::SELECT, SDLoc(N), VT, Cond, TruncOp0, TruncOp1);
6957 // Fold a series of buildvector, bitcast, and truncate if possible.
6959 // (2xi32 trunc (bitcast ((4xi32)buildvector x, x, y, y) 2xi64)) to
6960 // (2xi32 (buildvector x, y)).
6961 if (Level == AfterLegalizeVectorOps && VT.isVector() &&
6962 N0.getOpcode() == ISD::BITCAST && N0.hasOneUse() &&
6963 N0.getOperand(0).getOpcode() == ISD::BUILD_VECTOR &&
6964 N0.getOperand(0).hasOneUse()) {
6966 SDValue BuildVect = N0.getOperand(0);
6967 EVT BuildVectEltTy = BuildVect.getValueType().getVectorElementType();
6968 EVT TruncVecEltTy = VT.getVectorElementType();
6970 // Check that the element types match.
6971 if (BuildVectEltTy == TruncVecEltTy) {
6972 // Now we only need to compute the offset of the truncated elements.
6973 unsigned BuildVecNumElts = BuildVect.getNumOperands();
6974 unsigned TruncVecNumElts = VT.getVectorNumElements();
6975 unsigned TruncEltOffset = BuildVecNumElts / TruncVecNumElts;
6977 assert((BuildVecNumElts % TruncVecNumElts) == 0 &&
6978 "Invalid number of elements");
6980 SmallVector<SDValue, 8> Opnds;
6981 for (unsigned i = 0, e = BuildVecNumElts; i != e; i += TruncEltOffset)
6982 Opnds.push_back(BuildVect.getOperand(i));
6984 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, Opnds);
6988 // See if we can simplify the input to this truncate through knowledge that
6989 // only the low bits are being used.
6990 // For example "trunc (or (shl x, 8), y)" // -> trunc y
6991 // Currently we only perform this optimization on scalars because vectors
6992 // may have different active low bits.
6993 if (!VT.isVector()) {
6995 GetDemandedBits(N0, APInt::getLowBitsSet(N0.getValueSizeInBits(),
6996 VT.getSizeInBits()));
6997 if (Shorter.getNode())
6998 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Shorter);
7000 // fold (truncate (load x)) -> (smaller load x)
7001 // fold (truncate (srl (load x), c)) -> (smaller load (x+c/evtbits))
7002 if (!LegalTypes || TLI.isTypeDesirableForOp(N0.getOpcode(), VT)) {
7003 SDValue Reduced = ReduceLoadWidth(N);
7004 if (Reduced.getNode())
7006 // Handle the case where the load remains an extending load even
7007 // after truncation.
7008 if (N0.hasOneUse() && ISD::isUNINDEXEDLoad(N0.getNode())) {
7009 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
7010 if (!LN0->isVolatile() &&
7011 LN0->getMemoryVT().getStoreSizeInBits() < VT.getSizeInBits()) {
7012 SDValue NewLoad = DAG.getExtLoad(LN0->getExtensionType(), SDLoc(LN0),
7013 VT, LN0->getChain(), LN0->getBasePtr(),
7015 LN0->getMemOperand());
7016 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), NewLoad.getValue(1));
7021 // fold (trunc (concat ... x ...)) -> (concat ..., (trunc x), ...)),
7022 // where ... are all 'undef'.
7023 if (N0.getOpcode() == ISD::CONCAT_VECTORS && !LegalTypes) {
7024 SmallVector<EVT, 8> VTs;
7027 unsigned NumDefs = 0;
7029 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i) {
7030 SDValue X = N0.getOperand(i);
7031 if (X.getOpcode() != ISD::UNDEF) {
7036 // Stop if more than one members are non-undef.
7039 VTs.push_back(EVT::getVectorVT(*DAG.getContext(),
7040 VT.getVectorElementType(),
7041 X.getValueType().getVectorNumElements()));
7045 return DAG.getUNDEF(VT);
7048 assert(V.getNode() && "The single defined operand is empty!");
7049 SmallVector<SDValue, 8> Opnds;
7050 for (unsigned i = 0, e = VTs.size(); i != e; ++i) {
7052 Opnds.push_back(DAG.getUNDEF(VTs[i]));
7055 SDValue NV = DAG.getNode(ISD::TRUNCATE, SDLoc(V), VTs[i], V);
7056 AddToWorklist(NV.getNode());
7057 Opnds.push_back(NV);
7059 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT, Opnds);
7063 // Simplify the operands using demanded-bits information.
7064 if (!VT.isVector() &&
7065 SimplifyDemandedBits(SDValue(N, 0)))
7066 return SDValue(N, 0);
7071 static SDNode *getBuildPairElt(SDNode *N, unsigned i) {
7072 SDValue Elt = N->getOperand(i);
7073 if (Elt.getOpcode() != ISD::MERGE_VALUES)
7074 return Elt.getNode();
7075 return Elt.getOperand(Elt.getResNo()).getNode();
7078 /// build_pair (load, load) -> load
7079 /// if load locations are consecutive.
7080 SDValue DAGCombiner::CombineConsecutiveLoads(SDNode *N, EVT VT) {
7081 assert(N->getOpcode() == ISD::BUILD_PAIR);
7083 LoadSDNode *LD1 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 0));
7084 LoadSDNode *LD2 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 1));
7085 if (!LD1 || !LD2 || !ISD::isNON_EXTLoad(LD1) || !LD1->hasOneUse() ||
7086 LD1->getAddressSpace() != LD2->getAddressSpace())
7088 EVT LD1VT = LD1->getValueType(0);
7090 if (ISD::isNON_EXTLoad(LD2) &&
7092 // If both are volatile this would reduce the number of volatile loads.
7093 // If one is volatile it might be ok, but play conservative and bail out.
7094 !LD1->isVolatile() &&
7095 !LD2->isVolatile() &&
7096 DAG.isConsecutiveLoad(LD2, LD1, LD1VT.getSizeInBits()/8, 1)) {
7097 unsigned Align = LD1->getAlignment();
7098 unsigned NewAlign = TLI.getDataLayout()->
7099 getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
7101 if (NewAlign <= Align &&
7102 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT)))
7103 return DAG.getLoad(VT, SDLoc(N), LD1->getChain(),
7104 LD1->getBasePtr(), LD1->getPointerInfo(),
7105 false, false, false, Align);
7111 SDValue DAGCombiner::visitBITCAST(SDNode *N) {
7112 SDValue N0 = N->getOperand(0);
7113 EVT VT = N->getValueType(0);
7115 // If the input is a BUILD_VECTOR with all constant elements, fold this now.
7116 // Only do this before legalize, since afterward the target may be depending
7117 // on the bitconvert.
7118 // First check to see if this is all constant.
7120 N0.getOpcode() == ISD::BUILD_VECTOR && N0.getNode()->hasOneUse() &&
7122 bool isSimple = cast<BuildVectorSDNode>(N0)->isConstant();
7124 EVT DestEltVT = N->getValueType(0).getVectorElementType();
7125 assert(!DestEltVT.isVector() &&
7126 "Element type of vector ValueType must not be vector!");
7128 return ConstantFoldBITCASTofBUILD_VECTOR(N0.getNode(), DestEltVT);
7131 // If the input is a constant, let getNode fold it.
7132 if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
7133 // If we can't allow illegal operations, we need to check that this is just
7134 // a fp -> int or int -> conversion and that the resulting operation will
7136 if (!LegalOperations ||
7137 (isa<ConstantSDNode>(N0) && VT.isFloatingPoint() && !VT.isVector() &&
7138 TLI.isOperationLegal(ISD::ConstantFP, VT)) ||
7139 (isa<ConstantFPSDNode>(N0) && VT.isInteger() && !VT.isVector() &&
7140 TLI.isOperationLegal(ISD::Constant, VT)))
7141 return DAG.getNode(ISD::BITCAST, SDLoc(N), VT, N0);
7144 // (conv (conv x, t1), t2) -> (conv x, t2)
7145 if (N0.getOpcode() == ISD::BITCAST)
7146 return DAG.getNode(ISD::BITCAST, SDLoc(N), VT,
7149 // fold (conv (load x)) -> (load (conv*)x)
7150 // If the resultant load doesn't need a higher alignment than the original!
7151 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
7152 // Do not change the width of a volatile load.
7153 !cast<LoadSDNode>(N0)->isVolatile() &&
7154 // Do not remove the cast if the types differ in endian layout.
7155 TLI.hasBigEndianPartOrdering(N0.getValueType()) ==
7156 TLI.hasBigEndianPartOrdering(VT) &&
7157 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT)) &&
7158 TLI.isLoadBitCastBeneficial(N0.getValueType(), VT)) {
7159 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
7160 unsigned Align = TLI.getDataLayout()->
7161 getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
7162 unsigned OrigAlign = LN0->getAlignment();
7164 if (Align <= OrigAlign) {
7165 SDValue Load = DAG.getLoad(VT, SDLoc(N), LN0->getChain(),
7166 LN0->getBasePtr(), LN0->getPointerInfo(),
7167 LN0->isVolatile(), LN0->isNonTemporal(),
7168 LN0->isInvariant(), OrigAlign,
7170 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));
7175 // fold (bitconvert (fneg x)) -> (xor (bitconvert x), signbit)
7176 // fold (bitconvert (fabs x)) -> (and (bitconvert x), (not signbit))
7177 // This often reduces constant pool loads.
7178 if (((N0.getOpcode() == ISD::FNEG && !TLI.isFNegFree(N0.getValueType())) ||
7179 (N0.getOpcode() == ISD::FABS && !TLI.isFAbsFree(N0.getValueType()))) &&
7180 N0.getNode()->hasOneUse() && VT.isInteger() &&
7181 !VT.isVector() && !N0.getValueType().isVector()) {
7182 SDValue NewConv = DAG.getNode(ISD::BITCAST, SDLoc(N0), VT,
7184 AddToWorklist(NewConv.getNode());
7187 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
7188 if (N0.getOpcode() == ISD::FNEG)
7189 return DAG.getNode(ISD::XOR, DL, VT,
7190 NewConv, DAG.getConstant(SignBit, DL, VT));
7191 assert(N0.getOpcode() == ISD::FABS);
7192 return DAG.getNode(ISD::AND, DL, VT,
7193 NewConv, DAG.getConstant(~SignBit, DL, VT));
7196 // fold (bitconvert (fcopysign cst, x)) ->
7197 // (or (and (bitconvert x), sign), (and cst, (not sign)))
7198 // Note that we don't handle (copysign x, cst) because this can always be
7199 // folded to an fneg or fabs.
7200 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse() &&
7201 isa<ConstantFPSDNode>(N0.getOperand(0)) &&
7202 VT.isInteger() && !VT.isVector()) {
7203 unsigned OrigXWidth = N0.getOperand(1).getValueType().getSizeInBits();
7204 EVT IntXVT = EVT::getIntegerVT(*DAG.getContext(), OrigXWidth);
7205 if (isTypeLegal(IntXVT)) {
7206 SDValue X = DAG.getNode(ISD::BITCAST, SDLoc(N0),
7207 IntXVT, N0.getOperand(1));
7208 AddToWorklist(X.getNode());
7210 // If X has a different width than the result/lhs, sext it or truncate it.
7211 unsigned VTWidth = VT.getSizeInBits();
7212 if (OrigXWidth < VTWidth) {
7213 X = DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, X);
7214 AddToWorklist(X.getNode());
7215 } else if (OrigXWidth > VTWidth) {
7216 // To get the sign bit in the right place, we have to shift it right
7217 // before truncating.
7219 X = DAG.getNode(ISD::SRL, DL,
7220 X.getValueType(), X,
7221 DAG.getConstant(OrigXWidth-VTWidth, DL,
7223 AddToWorklist(X.getNode());
7224 X = DAG.getNode(ISD::TRUNCATE, SDLoc(X), VT, X);
7225 AddToWorklist(X.getNode());
7228 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
7229 X = DAG.getNode(ISD::AND, SDLoc(X), VT,
7230 X, DAG.getConstant(SignBit, SDLoc(X), VT));
7231 AddToWorklist(X.getNode());
7233 SDValue Cst = DAG.getNode(ISD::BITCAST, SDLoc(N0),
7234 VT, N0.getOperand(0));
7235 Cst = DAG.getNode(ISD::AND, SDLoc(Cst), VT,
7236 Cst, DAG.getConstant(~SignBit, SDLoc(Cst), VT));
7237 AddToWorklist(Cst.getNode());
7239 return DAG.getNode(ISD::OR, SDLoc(N), VT, X, Cst);
7243 // bitconvert(build_pair(ld, ld)) -> ld iff load locations are consecutive.
7244 if (N0.getOpcode() == ISD::BUILD_PAIR) {
7245 SDValue CombineLD = CombineConsecutiveLoads(N0.getNode(), VT);
7246 if (CombineLD.getNode())
7250 // Remove double bitcasts from shuffles - this is often a legacy of
7251 // XformToShuffleWithZero being used to combine bitmaskings (of
7252 // float vectors bitcast to integer vectors) into shuffles.
7253 // bitcast(shuffle(bitcast(s0),bitcast(s1))) -> shuffle(s0,s1)
7254 if (Level < AfterLegalizeDAG && TLI.isTypeLegal(VT) && VT.isVector() &&
7255 N0->getOpcode() == ISD::VECTOR_SHUFFLE &&
7256 VT.getVectorNumElements() >= N0.getValueType().getVectorNumElements() &&
7257 !(VT.getVectorNumElements() % N0.getValueType().getVectorNumElements())) {
7258 ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N0);
7260 // If operands are a bitcast, peek through if it casts the original VT.
7261 // If operands are a UNDEF or constant, just bitcast back to original VT.
7262 auto PeekThroughBitcast = [&](SDValue Op) {
7263 if (Op.getOpcode() == ISD::BITCAST &&
7264 Op.getOperand(0)->getValueType(0) == VT)
7265 return SDValue(Op.getOperand(0));
7266 if (ISD::isBuildVectorOfConstantSDNodes(Op.getNode()) ||
7267 ISD::isBuildVectorOfConstantFPSDNodes(Op.getNode()))
7268 return DAG.getNode(ISD::BITCAST, SDLoc(N), VT, Op);
7272 SDValue SV0 = PeekThroughBitcast(N0->getOperand(0));
7273 SDValue SV1 = PeekThroughBitcast(N0->getOperand(1));
7278 VT.getVectorNumElements() / N0.getValueType().getVectorNumElements();
7279 SmallVector<int, 8> NewMask;
7280 for (int M : SVN->getMask())
7281 for (int i = 0; i != MaskScale; ++i)
7282 NewMask.push_back(M < 0 ? -1 : M * MaskScale + i);
7284 bool LegalMask = TLI.isShuffleMaskLegal(NewMask, VT);
7286 std::swap(SV0, SV1);
7287 ShuffleVectorSDNode::commuteMask(NewMask);
7288 LegalMask = TLI.isShuffleMaskLegal(NewMask, VT);
7292 return DAG.getVectorShuffle(VT, SDLoc(N), SV0, SV1, NewMask);
7298 SDValue DAGCombiner::visitBUILD_PAIR(SDNode *N) {
7299 EVT VT = N->getValueType(0);
7300 return CombineConsecutiveLoads(N, VT);
7303 /// We know that BV is a build_vector node with Constant, ConstantFP or Undef
7304 /// operands. DstEltVT indicates the destination element value type.
7305 SDValue DAGCombiner::
7306 ConstantFoldBITCASTofBUILD_VECTOR(SDNode *BV, EVT DstEltVT) {
7307 EVT SrcEltVT = BV->getValueType(0).getVectorElementType();
7309 // If this is already the right type, we're done.
7310 if (SrcEltVT == DstEltVT) return SDValue(BV, 0);
7312 unsigned SrcBitSize = SrcEltVT.getSizeInBits();
7313 unsigned DstBitSize = DstEltVT.getSizeInBits();
7315 // If this is a conversion of N elements of one type to N elements of another
7316 // type, convert each element. This handles FP<->INT cases.
7317 if (SrcBitSize == DstBitSize) {
7318 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
7319 BV->getValueType(0).getVectorNumElements());
7321 // Due to the FP element handling below calling this routine recursively,
7322 // we can end up with a scalar-to-vector node here.
7323 if (BV->getOpcode() == ISD::SCALAR_TO_VECTOR)
7324 return DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(BV), VT,
7325 DAG.getNode(ISD::BITCAST, SDLoc(BV),
7326 DstEltVT, BV->getOperand(0)));
7328 SmallVector<SDValue, 8> Ops;
7329 for (SDValue Op : BV->op_values()) {
7330 // If the vector element type is not legal, the BUILD_VECTOR operands
7331 // are promoted and implicitly truncated. Make that explicit here.
7332 if (Op.getValueType() != SrcEltVT)
7333 Op = DAG.getNode(ISD::TRUNCATE, SDLoc(BV), SrcEltVT, Op);
7334 Ops.push_back(DAG.getNode(ISD::BITCAST, SDLoc(BV),
7336 AddToWorklist(Ops.back().getNode());
7338 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(BV), VT, Ops);
7341 // Otherwise, we're growing or shrinking the elements. To avoid having to
7342 // handle annoying details of growing/shrinking FP values, we convert them to
7344 if (SrcEltVT.isFloatingPoint()) {
7345 // Convert the input float vector to a int vector where the elements are the
7347 EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), SrcEltVT.getSizeInBits());
7348 BV = ConstantFoldBITCASTofBUILD_VECTOR(BV, IntVT).getNode();
7352 // Now we know the input is an integer vector. If the output is a FP type,
7353 // convert to integer first, then to FP of the right size.
7354 if (DstEltVT.isFloatingPoint()) {
7355 EVT TmpVT = EVT::getIntegerVT(*DAG.getContext(), DstEltVT.getSizeInBits());
7356 SDNode *Tmp = ConstantFoldBITCASTofBUILD_VECTOR(BV, TmpVT).getNode();
7358 // Next, convert to FP elements of the same size.
7359 return ConstantFoldBITCASTofBUILD_VECTOR(Tmp, DstEltVT);
7364 // Okay, we know the src/dst types are both integers of differing types.
7365 // Handling growing first.
7366 assert(SrcEltVT.isInteger() && DstEltVT.isInteger());
7367 if (SrcBitSize < DstBitSize) {
7368 unsigned NumInputsPerOutput = DstBitSize/SrcBitSize;
7370 SmallVector<SDValue, 8> Ops;
7371 for (unsigned i = 0, e = BV->getNumOperands(); i != e;
7372 i += NumInputsPerOutput) {
7373 bool isLE = TLI.isLittleEndian();
7374 APInt NewBits = APInt(DstBitSize, 0);
7375 bool EltIsUndef = true;
7376 for (unsigned j = 0; j != NumInputsPerOutput; ++j) {
7377 // Shift the previously computed bits over.
7378 NewBits <<= SrcBitSize;
7379 SDValue Op = BV->getOperand(i+ (isLE ? (NumInputsPerOutput-j-1) : j));
7380 if (Op.getOpcode() == ISD::UNDEF) continue;
7383 NewBits |= cast<ConstantSDNode>(Op)->getAPIntValue().
7384 zextOrTrunc(SrcBitSize).zext(DstBitSize);
7388 Ops.push_back(DAG.getUNDEF(DstEltVT));
7390 Ops.push_back(DAG.getConstant(NewBits, DL, DstEltVT));
7393 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT, Ops.size());
7394 return DAG.getNode(ISD::BUILD_VECTOR, DL, VT, Ops);
7397 // Finally, this must be the case where we are shrinking elements: each input
7398 // turns into multiple outputs.
7399 unsigned NumOutputsPerInput = SrcBitSize/DstBitSize;
7400 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
7401 NumOutputsPerInput*BV->getNumOperands());
7402 SmallVector<SDValue, 8> Ops;
7404 for (const SDValue &Op : BV->op_values()) {
7405 if (Op.getOpcode() == ISD::UNDEF) {
7406 Ops.append(NumOutputsPerInput, DAG.getUNDEF(DstEltVT));
7410 APInt OpVal = cast<ConstantSDNode>(Op)->
7411 getAPIntValue().zextOrTrunc(SrcBitSize);
7413 for (unsigned j = 0; j != NumOutputsPerInput; ++j) {
7414 APInt ThisVal = OpVal.trunc(DstBitSize);
7415 Ops.push_back(DAG.getConstant(ThisVal, DL, DstEltVT));
7416 OpVal = OpVal.lshr(DstBitSize);
7419 // For big endian targets, swap the order of the pieces of each element.
7420 if (TLI.isBigEndian())
7421 std::reverse(Ops.end()-NumOutputsPerInput, Ops.end());
7424 return DAG.getNode(ISD::BUILD_VECTOR, DL, VT, Ops);
7427 /// Try to perform FMA combining on a given FADD node.
7428 SDValue DAGCombiner::visitFADDForFMACombine(SDNode *N) {
7429 SDValue N0 = N->getOperand(0);
7430 SDValue N1 = N->getOperand(1);
7431 EVT VT = N->getValueType(0);
7434 const TargetOptions &Options = DAG.getTarget().Options;
7435 bool UnsafeFPMath = (Options.AllowFPOpFusion == FPOpFusion::Fast ||
7436 Options.UnsafeFPMath);
7438 // Floating-point multiply-add with intermediate rounding.
7439 bool HasFMAD = (LegalOperations &&
7440 TLI.isOperationLegal(ISD::FMAD, VT));
7442 // Floating-point multiply-add without intermediate rounding.
7443 bool HasFMA = ((!LegalOperations ||
7444 TLI.isOperationLegalOrCustom(ISD::FMA, VT)) &&
7445 TLI.isFMAFasterThanFMulAndFAdd(VT) &&
7448 // No valid opcode, do not combine.
7449 if (!HasFMAD && !HasFMA)
7452 // Always prefer FMAD to FMA for precision.
7453 unsigned int PreferredFusedOpcode = HasFMAD ? ISD::FMAD : ISD::FMA;
7454 bool Aggressive = TLI.enableAggressiveFMAFusion(VT);
7455 bool LookThroughFPExt = TLI.isFPExtFree(VT);
7457 // fold (fadd (fmul x, y), z) -> (fma x, y, z)
7458 if (N0.getOpcode() == ISD::FMUL &&
7459 (Aggressive || N0->hasOneUse())) {
7460 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7461 N0.getOperand(0), N0.getOperand(1), N1);
7464 // fold (fadd x, (fmul y, z)) -> (fma y, z, x)
7465 // Note: Commutes FADD operands.
7466 if (N1.getOpcode() == ISD::FMUL &&
7467 (Aggressive || N1->hasOneUse())) {
7468 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7469 N1.getOperand(0), N1.getOperand(1), N0);
7472 // Look through FP_EXTEND nodes to do more combining.
7473 if (UnsafeFPMath && LookThroughFPExt) {
7474 // fold (fadd (fpext (fmul x, y)), z) -> (fma (fpext x), (fpext y), z)
7475 if (N0.getOpcode() == ISD::FP_EXTEND) {
7476 SDValue N00 = N0.getOperand(0);
7477 if (N00.getOpcode() == ISD::FMUL)
7478 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7479 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7481 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7482 N00.getOperand(1)), N1);
7485 // fold (fadd x, (fpext (fmul y, z))) -> (fma (fpext y), (fpext z), x)
7486 // Note: Commutes FADD operands.
7487 if (N1.getOpcode() == ISD::FP_EXTEND) {
7488 SDValue N10 = N1.getOperand(0);
7489 if (N10.getOpcode() == ISD::FMUL)
7490 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7491 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7493 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7494 N10.getOperand(1)), N0);
7498 // More folding opportunities when target permits.
7499 if ((UnsafeFPMath || HasFMAD) && Aggressive) {
7500 // fold (fadd (fma x, y, (fmul u, v)), z) -> (fma x, y (fma u, v, z))
7501 if (N0.getOpcode() == PreferredFusedOpcode &&
7502 N0.getOperand(2).getOpcode() == ISD::FMUL) {
7503 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7504 N0.getOperand(0), N0.getOperand(1),
7505 DAG.getNode(PreferredFusedOpcode, SL, VT,
7506 N0.getOperand(2).getOperand(0),
7507 N0.getOperand(2).getOperand(1),
7511 // fold (fadd x, (fma y, z, (fmul u, v)) -> (fma y, z (fma u, v, x))
7512 if (N1->getOpcode() == PreferredFusedOpcode &&
7513 N1.getOperand(2).getOpcode() == ISD::FMUL) {
7514 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7515 N1.getOperand(0), N1.getOperand(1),
7516 DAG.getNode(PreferredFusedOpcode, SL, VT,
7517 N1.getOperand(2).getOperand(0),
7518 N1.getOperand(2).getOperand(1),
7522 if (UnsafeFPMath && LookThroughFPExt) {
7523 // fold (fadd (fma x, y, (fpext (fmul u, v))), z)
7524 // -> (fma x, y, (fma (fpext u), (fpext v), z))
7525 auto FoldFAddFMAFPExtFMul = [&] (
7526 SDValue X, SDValue Y, SDValue U, SDValue V, SDValue Z) {
7527 return DAG.getNode(PreferredFusedOpcode, SL, VT, X, Y,
7528 DAG.getNode(PreferredFusedOpcode, SL, VT,
7529 DAG.getNode(ISD::FP_EXTEND, SL, VT, U),
7530 DAG.getNode(ISD::FP_EXTEND, SL, VT, V),
7533 if (N0.getOpcode() == PreferredFusedOpcode) {
7534 SDValue N02 = N0.getOperand(2);
7535 if (N02.getOpcode() == ISD::FP_EXTEND) {
7536 SDValue N020 = N02.getOperand(0);
7537 if (N020.getOpcode() == ISD::FMUL)
7538 return FoldFAddFMAFPExtFMul(N0.getOperand(0), N0.getOperand(1),
7539 N020.getOperand(0), N020.getOperand(1),
7544 // fold (fadd (fpext (fma x, y, (fmul u, v))), z)
7545 // -> (fma (fpext x), (fpext y), (fma (fpext u), (fpext v), z))
7546 // FIXME: This turns two single-precision and one double-precision
7547 // operation into two double-precision operations, which might not be
7548 // interesting for all targets, especially GPUs.
7549 auto FoldFAddFPExtFMAFMul = [&] (
7550 SDValue X, SDValue Y, SDValue U, SDValue V, SDValue Z) {
7551 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7552 DAG.getNode(ISD::FP_EXTEND, SL, VT, X),
7553 DAG.getNode(ISD::FP_EXTEND, SL, VT, Y),
7554 DAG.getNode(PreferredFusedOpcode, SL, VT,
7555 DAG.getNode(ISD::FP_EXTEND, SL, VT, U),
7556 DAG.getNode(ISD::FP_EXTEND, SL, VT, V),
7559 if (N0.getOpcode() == ISD::FP_EXTEND) {
7560 SDValue N00 = N0.getOperand(0);
7561 if (N00.getOpcode() == PreferredFusedOpcode) {
7562 SDValue N002 = N00.getOperand(2);
7563 if (N002.getOpcode() == ISD::FMUL)
7564 return FoldFAddFPExtFMAFMul(N00.getOperand(0), N00.getOperand(1),
7565 N002.getOperand(0), N002.getOperand(1),
7570 // fold (fadd x, (fma y, z, (fpext (fmul u, v)))
7571 // -> (fma y, z, (fma (fpext u), (fpext v), x))
7572 if (N1.getOpcode() == PreferredFusedOpcode) {
7573 SDValue N12 = N1.getOperand(2);
7574 if (N12.getOpcode() == ISD::FP_EXTEND) {
7575 SDValue N120 = N12.getOperand(0);
7576 if (N120.getOpcode() == ISD::FMUL)
7577 return FoldFAddFMAFPExtFMul(N1.getOperand(0), N1.getOperand(1),
7578 N120.getOperand(0), N120.getOperand(1),
7583 // fold (fadd x, (fpext (fma y, z, (fmul u, v)))
7584 // -> (fma (fpext y), (fpext z), (fma (fpext u), (fpext v), x))
7585 // FIXME: This turns two single-precision and one double-precision
7586 // operation into two double-precision operations, which might not be
7587 // interesting for all targets, especially GPUs.
7588 if (N1.getOpcode() == ISD::FP_EXTEND) {
7589 SDValue N10 = N1.getOperand(0);
7590 if (N10.getOpcode() == PreferredFusedOpcode) {
7591 SDValue N102 = N10.getOperand(2);
7592 if (N102.getOpcode() == ISD::FMUL)
7593 return FoldFAddFPExtFMAFMul(N10.getOperand(0), N10.getOperand(1),
7594 N102.getOperand(0), N102.getOperand(1),
7604 /// Try to perform FMA combining on a given FSUB node.
7605 SDValue DAGCombiner::visitFSUBForFMACombine(SDNode *N) {
7606 SDValue N0 = N->getOperand(0);
7607 SDValue N1 = N->getOperand(1);
7608 EVT VT = N->getValueType(0);
7611 const TargetOptions &Options = DAG.getTarget().Options;
7612 bool UnsafeFPMath = (Options.AllowFPOpFusion == FPOpFusion::Fast ||
7613 Options.UnsafeFPMath);
7615 // Floating-point multiply-add with intermediate rounding.
7616 bool HasFMAD = (LegalOperations &&
7617 TLI.isOperationLegal(ISD::FMAD, VT));
7619 // Floating-point multiply-add without intermediate rounding.
7620 bool HasFMA = ((!LegalOperations ||
7621 TLI.isOperationLegalOrCustom(ISD::FMA, VT)) &&
7622 TLI.isFMAFasterThanFMulAndFAdd(VT) &&
7625 // No valid opcode, do not combine.
7626 if (!HasFMAD && !HasFMA)
7629 // Always prefer FMAD to FMA for precision.
7630 unsigned int PreferredFusedOpcode = HasFMAD ? ISD::FMAD : ISD::FMA;
7631 bool Aggressive = TLI.enableAggressiveFMAFusion(VT);
7632 bool LookThroughFPExt = TLI.isFPExtFree(VT);
7634 // fold (fsub (fmul x, y), z) -> (fma x, y, (fneg z))
7635 if (N0.getOpcode() == ISD::FMUL &&
7636 (Aggressive || N0->hasOneUse())) {
7637 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7638 N0.getOperand(0), N0.getOperand(1),
7639 DAG.getNode(ISD::FNEG, SL, VT, N1));
7642 // fold (fsub x, (fmul y, z)) -> (fma (fneg y), z, x)
7643 // Note: Commutes FSUB operands.
7644 if (N1.getOpcode() == ISD::FMUL &&
7645 (Aggressive || N1->hasOneUse()))
7646 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7647 DAG.getNode(ISD::FNEG, SL, VT,
7649 N1.getOperand(1), N0);
7651 // fold (fsub (fneg (fmul, x, y)), z) -> (fma (fneg x), y, (fneg z))
7652 if (N0.getOpcode() == ISD::FNEG &&
7653 N0.getOperand(0).getOpcode() == ISD::FMUL &&
7654 (Aggressive || (N0->hasOneUse() && N0.getOperand(0).hasOneUse()))) {
7655 SDValue N00 = N0.getOperand(0).getOperand(0);
7656 SDValue N01 = N0.getOperand(0).getOperand(1);
7657 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7658 DAG.getNode(ISD::FNEG, SL, VT, N00), N01,
7659 DAG.getNode(ISD::FNEG, SL, VT, N1));
7662 // Look through FP_EXTEND nodes to do more combining.
7663 if (UnsafeFPMath && LookThroughFPExt) {
7664 // fold (fsub (fpext (fmul x, y)), z)
7665 // -> (fma (fpext x), (fpext y), (fneg z))
7666 if (N0.getOpcode() == ISD::FP_EXTEND) {
7667 SDValue N00 = N0.getOperand(0);
7668 if (N00.getOpcode() == ISD::FMUL)
7669 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7670 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7672 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7674 DAG.getNode(ISD::FNEG, SL, VT, N1));
7677 // fold (fsub x, (fpext (fmul y, z)))
7678 // -> (fma (fneg (fpext y)), (fpext z), x)
7679 // Note: Commutes FSUB operands.
7680 if (N1.getOpcode() == ISD::FP_EXTEND) {
7681 SDValue N10 = N1.getOperand(0);
7682 if (N10.getOpcode() == ISD::FMUL)
7683 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7684 DAG.getNode(ISD::FNEG, SL, VT,
7685 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7686 N10.getOperand(0))),
7687 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7692 // fold (fsub (fpext (fneg (fmul, x, y))), z)
7693 // -> (fneg (fma (fpext x), (fpext y), z))
7694 // Note: This could be removed with appropriate canonicalization of the
7695 // input expression into (fneg (fadd (fpext (fmul, x, y)), z). However, the
7696 // orthogonal flags -fp-contract=fast and -enable-unsafe-fp-math prevent
7697 // from implementing the canonicalization in visitFSUB.
7698 if (N0.getOpcode() == ISD::FP_EXTEND) {
7699 SDValue N00 = N0.getOperand(0);
7700 if (N00.getOpcode() == ISD::FNEG) {
7701 SDValue N000 = N00.getOperand(0);
7702 if (N000.getOpcode() == ISD::FMUL) {
7703 return DAG.getNode(ISD::FNEG, SL, VT,
7704 DAG.getNode(PreferredFusedOpcode, SL, VT,
7705 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7706 N000.getOperand(0)),
7707 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7708 N000.getOperand(1)),
7714 // fold (fsub (fneg (fpext (fmul, x, y))), z)
7715 // -> (fneg (fma (fpext x)), (fpext y), z)
7716 // Note: This could be removed with appropriate canonicalization of the
7717 // input expression into (fneg (fadd (fpext (fmul, x, y)), z). However, the
7718 // orthogonal flags -fp-contract=fast and -enable-unsafe-fp-math prevent
7719 // from implementing the canonicalization in visitFSUB.
7720 if (N0.getOpcode() == ISD::FNEG) {
7721 SDValue N00 = N0.getOperand(0);
7722 if (N00.getOpcode() == ISD::FP_EXTEND) {
7723 SDValue N000 = N00.getOperand(0);
7724 if (N000.getOpcode() == ISD::FMUL) {
7725 return DAG.getNode(ISD::FNEG, SL, VT,
7726 DAG.getNode(PreferredFusedOpcode, SL, VT,
7727 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7728 N000.getOperand(0)),
7729 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7730 N000.getOperand(1)),
7738 // More folding opportunities when target permits.
7739 if ((UnsafeFPMath || HasFMAD) && Aggressive) {
7740 // fold (fsub (fma x, y, (fmul u, v)), z)
7741 // -> (fma x, y (fma u, v, (fneg z)))
7742 if (N0.getOpcode() == PreferredFusedOpcode &&
7743 N0.getOperand(2).getOpcode() == ISD::FMUL) {
7744 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7745 N0.getOperand(0), N0.getOperand(1),
7746 DAG.getNode(PreferredFusedOpcode, SL, VT,
7747 N0.getOperand(2).getOperand(0),
7748 N0.getOperand(2).getOperand(1),
7749 DAG.getNode(ISD::FNEG, SL, VT,
7753 // fold (fsub x, (fma y, z, (fmul u, v)))
7754 // -> (fma (fneg y), z, (fma (fneg u), v, x))
7755 if (N1.getOpcode() == PreferredFusedOpcode &&
7756 N1.getOperand(2).getOpcode() == ISD::FMUL) {
7757 SDValue N20 = N1.getOperand(2).getOperand(0);
7758 SDValue N21 = N1.getOperand(2).getOperand(1);
7759 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7760 DAG.getNode(ISD::FNEG, SL, VT,
7763 DAG.getNode(PreferredFusedOpcode, SL, VT,
7764 DAG.getNode(ISD::FNEG, SL, VT, N20),
7769 if (UnsafeFPMath && LookThroughFPExt) {
7770 // fold (fsub (fma x, y, (fpext (fmul u, v))), z)
7771 // -> (fma x, y (fma (fpext u), (fpext v), (fneg z)))
7772 if (N0.getOpcode() == PreferredFusedOpcode) {
7773 SDValue N02 = N0.getOperand(2);
7774 if (N02.getOpcode() == ISD::FP_EXTEND) {
7775 SDValue N020 = N02.getOperand(0);
7776 if (N020.getOpcode() == ISD::FMUL)
7777 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7778 N0.getOperand(0), N0.getOperand(1),
7779 DAG.getNode(PreferredFusedOpcode, SL, VT,
7780 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7781 N020.getOperand(0)),
7782 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7783 N020.getOperand(1)),
7784 DAG.getNode(ISD::FNEG, SL, VT,
7789 // fold (fsub (fpext (fma x, y, (fmul u, v))), z)
7790 // -> (fma (fpext x), (fpext y),
7791 // (fma (fpext u), (fpext v), (fneg z)))
7792 // FIXME: This turns two single-precision and one double-precision
7793 // operation into two double-precision operations, which might not be
7794 // interesting for all targets, especially GPUs.
7795 if (N0.getOpcode() == ISD::FP_EXTEND) {
7796 SDValue N00 = N0.getOperand(0);
7797 if (N00.getOpcode() == PreferredFusedOpcode) {
7798 SDValue N002 = N00.getOperand(2);
7799 if (N002.getOpcode() == ISD::FMUL)
7800 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7801 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7803 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7805 DAG.getNode(PreferredFusedOpcode, SL, VT,
7806 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7807 N002.getOperand(0)),
7808 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7809 N002.getOperand(1)),
7810 DAG.getNode(ISD::FNEG, SL, VT,
7815 // fold (fsub x, (fma y, z, (fpext (fmul u, v))))
7816 // -> (fma (fneg y), z, (fma (fneg (fpext u)), (fpext v), x))
7817 if (N1.getOpcode() == PreferredFusedOpcode &&
7818 N1.getOperand(2).getOpcode() == ISD::FP_EXTEND) {
7819 SDValue N120 = N1.getOperand(2).getOperand(0);
7820 if (N120.getOpcode() == ISD::FMUL) {
7821 SDValue N1200 = N120.getOperand(0);
7822 SDValue N1201 = N120.getOperand(1);
7823 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7824 DAG.getNode(ISD::FNEG, SL, VT, N1.getOperand(0)),
7826 DAG.getNode(PreferredFusedOpcode, SL, VT,
7827 DAG.getNode(ISD::FNEG, SL, VT,
7828 DAG.getNode(ISD::FP_EXTEND, SL,
7830 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7836 // fold (fsub x, (fpext (fma y, z, (fmul u, v))))
7837 // -> (fma (fneg (fpext y)), (fpext z),
7838 // (fma (fneg (fpext u)), (fpext v), x))
7839 // FIXME: This turns two single-precision and one double-precision
7840 // operation into two double-precision operations, which might not be
7841 // interesting for all targets, especially GPUs.
7842 if (N1.getOpcode() == ISD::FP_EXTEND &&
7843 N1.getOperand(0).getOpcode() == PreferredFusedOpcode) {
7844 SDValue N100 = N1.getOperand(0).getOperand(0);
7845 SDValue N101 = N1.getOperand(0).getOperand(1);
7846 SDValue N102 = N1.getOperand(0).getOperand(2);
7847 if (N102.getOpcode() == ISD::FMUL) {
7848 SDValue N1020 = N102.getOperand(0);
7849 SDValue N1021 = N102.getOperand(1);
7850 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7851 DAG.getNode(ISD::FNEG, SL, VT,
7852 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7854 DAG.getNode(ISD::FP_EXTEND, SL, VT, N101),
7855 DAG.getNode(PreferredFusedOpcode, SL, VT,
7856 DAG.getNode(ISD::FNEG, SL, VT,
7857 DAG.getNode(ISD::FP_EXTEND, SL,
7859 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7870 SDValue DAGCombiner::visitFADD(SDNode *N) {
7871 SDValue N0 = N->getOperand(0);
7872 SDValue N1 = N->getOperand(1);
7873 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
7874 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
7875 EVT VT = N->getValueType(0);
7877 const TargetOptions &Options = DAG.getTarget().Options;
7881 if (SDValue FoldedVOp = SimplifyVBinOp(N))
7884 // fold (fadd c1, c2) -> c1 + c2
7886 return DAG.getNode(ISD::FADD, DL, VT, N0, N1);
7888 // canonicalize constant to RHS
7889 if (N0CFP && !N1CFP)
7890 return DAG.getNode(ISD::FADD, DL, VT, N1, N0);
7892 // fold (fadd A, (fneg B)) -> (fsub A, B)
7893 if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
7894 isNegatibleForFree(N1, LegalOperations, TLI, &Options) == 2)
7895 return DAG.getNode(ISD::FSUB, DL, VT, N0,
7896 GetNegatedExpression(N1, DAG, LegalOperations));
7898 // fold (fadd (fneg A), B) -> (fsub B, A)
7899 if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
7900 isNegatibleForFree(N0, LegalOperations, TLI, &Options) == 2)
7901 return DAG.getNode(ISD::FSUB, DL, VT, N1,
7902 GetNegatedExpression(N0, DAG, LegalOperations));
7904 // If 'unsafe math' is enabled, fold lots of things.
7905 if (Options.UnsafeFPMath) {
7906 // No FP constant should be created after legalization as Instruction
7907 // Selection pass has a hard time dealing with FP constants.
7908 bool AllowNewConst = (Level < AfterLegalizeDAG);
7910 // fold (fadd A, 0) -> A
7911 if (N1CFP && N1CFP->isZero())
7914 // fold (fadd (fadd x, c1), c2) -> (fadd x, (fadd c1, c2))
7915 if (N1CFP && N0.getOpcode() == ISD::FADD && N0.getNode()->hasOneUse() &&
7916 isa<ConstantFPSDNode>(N0.getOperand(1)))
7917 return DAG.getNode(ISD::FADD, DL, VT, N0.getOperand(0),
7918 DAG.getNode(ISD::FADD, DL, VT, N0.getOperand(1), N1));
7920 // If allowed, fold (fadd (fneg x), x) -> 0.0
7921 if (AllowNewConst && N0.getOpcode() == ISD::FNEG && N0.getOperand(0) == N1)
7922 return DAG.getConstantFP(0.0, DL, VT);
7924 // If allowed, fold (fadd x, (fneg x)) -> 0.0
7925 if (AllowNewConst && N1.getOpcode() == ISD::FNEG && N1.getOperand(0) == N0)
7926 return DAG.getConstantFP(0.0, DL, VT);
7928 // We can fold chains of FADD's of the same value into multiplications.
7929 // This transform is not safe in general because we are reducing the number
7930 // of rounding steps.
7931 if (TLI.isOperationLegalOrCustom(ISD::FMUL, VT) && !N0CFP && !N1CFP) {
7932 if (N0.getOpcode() == ISD::FMUL) {
7933 ConstantFPSDNode *CFP00 = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
7934 ConstantFPSDNode *CFP01 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
7936 // (fadd (fmul x, c), x) -> (fmul x, c+1)
7937 if (CFP01 && !CFP00 && N0.getOperand(0) == N1) {
7938 SDValue NewCFP = DAG.getNode(ISD::FADD, DL, VT, SDValue(CFP01, 0),
7939 DAG.getConstantFP(1.0, DL, VT));
7940 return DAG.getNode(ISD::FMUL, DL, VT, N1, NewCFP);
7943 // (fadd (fmul x, c), (fadd x, x)) -> (fmul x, c+2)
7944 if (CFP01 && !CFP00 && N1.getOpcode() == ISD::FADD &&
7945 N1.getOperand(0) == N1.getOperand(1) &&
7946 N0.getOperand(0) == N1.getOperand(0)) {
7947 SDValue NewCFP = DAG.getNode(ISD::FADD, DL, VT, SDValue(CFP01, 0),
7948 DAG.getConstantFP(2.0, DL, VT));
7949 return DAG.getNode(ISD::FMUL, DL, VT, N0.getOperand(0), NewCFP);
7953 if (N1.getOpcode() == ISD::FMUL) {
7954 ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
7955 ConstantFPSDNode *CFP11 = dyn_cast<ConstantFPSDNode>(N1.getOperand(1));
7957 // (fadd x, (fmul x, c)) -> (fmul x, c+1)
7958 if (CFP11 && !CFP10 && N1.getOperand(0) == N0) {
7959 SDValue NewCFP = DAG.getNode(ISD::FADD, DL, VT, SDValue(CFP11, 0),
7960 DAG.getConstantFP(1.0, DL, VT));
7961 return DAG.getNode(ISD::FMUL, DL, VT, N0, NewCFP);
7964 // (fadd (fadd x, x), (fmul x, c)) -> (fmul x, c+2)
7965 if (CFP11 && !CFP10 && N0.getOpcode() == ISD::FADD &&
7966 N0.getOperand(0) == N0.getOperand(1) &&
7967 N1.getOperand(0) == N0.getOperand(0)) {
7968 SDValue NewCFP = DAG.getNode(ISD::FADD, DL, VT, SDValue(CFP11, 0),
7969 DAG.getConstantFP(2.0, DL, VT));
7970 return DAG.getNode(ISD::FMUL, DL, VT, N1.getOperand(0), NewCFP);
7974 if (N0.getOpcode() == ISD::FADD && AllowNewConst) {
7975 ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
7976 // (fadd (fadd x, x), x) -> (fmul x, 3.0)
7977 if (!CFP && N0.getOperand(0) == N0.getOperand(1) &&
7978 (N0.getOperand(0) == N1)) {
7979 return DAG.getNode(ISD::FMUL, DL, VT,
7980 N1, DAG.getConstantFP(3.0, DL, VT));
7984 if (N1.getOpcode() == ISD::FADD && AllowNewConst) {
7985 ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
7986 // (fadd x, (fadd x, x)) -> (fmul x, 3.0)
7987 if (!CFP10 && N1.getOperand(0) == N1.getOperand(1) &&
7988 N1.getOperand(0) == N0) {
7989 return DAG.getNode(ISD::FMUL, DL, VT,
7990 N0, DAG.getConstantFP(3.0, DL, VT));
7994 // (fadd (fadd x, x), (fadd x, x)) -> (fmul x, 4.0)
7995 if (AllowNewConst &&
7996 N0.getOpcode() == ISD::FADD && N1.getOpcode() == ISD::FADD &&
7997 N0.getOperand(0) == N0.getOperand(1) &&
7998 N1.getOperand(0) == N1.getOperand(1) &&
7999 N0.getOperand(0) == N1.getOperand(0)) {
8000 return DAG.getNode(ISD::FMUL, DL, VT,
8001 N0.getOperand(0), DAG.getConstantFP(4.0, DL, VT));
8004 } // enable-unsafe-fp-math
8006 // FADD -> FMA combines:
8007 SDValue Fused = visitFADDForFMACombine(N);
8009 AddToWorklist(Fused.getNode());
8016 SDValue DAGCombiner::visitFSUB(SDNode *N) {
8017 SDValue N0 = N->getOperand(0);
8018 SDValue N1 = N->getOperand(1);
8019 ConstantFPSDNode *N0CFP = isConstOrConstSplatFP(N0);
8020 ConstantFPSDNode *N1CFP = isConstOrConstSplatFP(N1);
8021 EVT VT = N->getValueType(0);
8023 const TargetOptions &Options = DAG.getTarget().Options;
8027 if (SDValue FoldedVOp = SimplifyVBinOp(N))
8030 // fold (fsub c1, c2) -> c1-c2
8032 return DAG.getNode(ISD::FSUB, dl, VT, N0, N1);
8034 // fold (fsub A, (fneg B)) -> (fadd A, B)
8035 if (isNegatibleForFree(N1, LegalOperations, TLI, &Options))
8036 return DAG.getNode(ISD::FADD, dl, VT, N0,
8037 GetNegatedExpression(N1, DAG, LegalOperations));
8039 // If 'unsafe math' is enabled, fold lots of things.
8040 if (Options.UnsafeFPMath) {
8042 if (N1CFP && N1CFP->isZero())
8045 // (fsub 0, B) -> -B
8046 if (N0CFP && N0CFP->isZero()) {
8047 if (isNegatibleForFree(N1, LegalOperations, TLI, &Options))
8048 return GetNegatedExpression(N1, DAG, LegalOperations);
8049 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
8050 return DAG.getNode(ISD::FNEG, dl, VT, N1);
8053 // (fsub x, x) -> 0.0
8055 return DAG.getConstantFP(0.0f, dl, VT);
8057 // (fsub x, (fadd x, y)) -> (fneg y)
8058 // (fsub x, (fadd y, x)) -> (fneg y)
8059 if (N1.getOpcode() == ISD::FADD) {
8060 SDValue N10 = N1->getOperand(0);
8061 SDValue N11 = N1->getOperand(1);
8063 if (N10 == N0 && isNegatibleForFree(N11, LegalOperations, TLI, &Options))
8064 return GetNegatedExpression(N11, DAG, LegalOperations);
8066 if (N11 == N0 && isNegatibleForFree(N10, LegalOperations, TLI, &Options))
8067 return GetNegatedExpression(N10, DAG, LegalOperations);
8071 // FSUB -> FMA combines:
8072 SDValue Fused = visitFSUBForFMACombine(N);
8074 AddToWorklist(Fused.getNode());
8081 SDValue DAGCombiner::visitFMUL(SDNode *N) {
8082 SDValue N0 = N->getOperand(0);
8083 SDValue N1 = N->getOperand(1);
8084 ConstantFPSDNode *N0CFP = isConstOrConstSplatFP(N0);
8085 ConstantFPSDNode *N1CFP = isConstOrConstSplatFP(N1);
8086 EVT VT = N->getValueType(0);
8088 const TargetOptions &Options = DAG.getTarget().Options;
8091 if (VT.isVector()) {
8092 // This just handles C1 * C2 for vectors. Other vector folds are below.
8093 if (SDValue FoldedVOp = SimplifyVBinOp(N))
8097 // fold (fmul c1, c2) -> c1*c2
8099 return DAG.getNode(ISD::FMUL, DL, VT, N0, N1);
8101 // canonicalize constant to RHS
8102 if (isConstantFPBuildVectorOrConstantFP(N0) &&
8103 !isConstantFPBuildVectorOrConstantFP(N1))
8104 return DAG.getNode(ISD::FMUL, DL, VT, N1, N0);
8106 // fold (fmul A, 1.0) -> A
8107 if (N1CFP && N1CFP->isExactlyValue(1.0))
8110 if (Options.UnsafeFPMath) {
8111 // fold (fmul A, 0) -> 0
8112 if (N1CFP && N1CFP->isZero())
8115 // fold (fmul (fmul x, c1), c2) -> (fmul x, (fmul c1, c2))
8116 if (N0.getOpcode() == ISD::FMUL) {
8117 // Fold scalars or any vector constants (not just splats).
8118 // This fold is done in general by InstCombine, but extra fmul insts
8119 // may have been generated during lowering.
8120 SDValue N00 = N0.getOperand(0);
8121 SDValue N01 = N0.getOperand(1);
8122 auto *BV1 = dyn_cast<BuildVectorSDNode>(N1);
8123 auto *BV00 = dyn_cast<BuildVectorSDNode>(N00);
8124 auto *BV01 = dyn_cast<BuildVectorSDNode>(N01);
8126 // Check 1: Make sure that the first operand of the inner multiply is NOT
8127 // a constant. Otherwise, we may induce infinite looping.
8128 if (!(isConstOrConstSplatFP(N00) || (BV00 && BV00->isConstant()))) {
8129 // Check 2: Make sure that the second operand of the inner multiply and
8130 // the second operand of the outer multiply are constants.
8131 if ((N1CFP && isConstOrConstSplatFP(N01)) ||
8132 (BV1 && BV01 && BV1->isConstant() && BV01->isConstant())) {
8133 SDValue MulConsts = DAG.getNode(ISD::FMUL, DL, VT, N01, N1);
8134 return DAG.getNode(ISD::FMUL, DL, VT, N00, MulConsts);
8139 // fold (fmul (fadd x, x), c) -> (fmul x, (fmul 2.0, c))
8140 // Undo the fmul 2.0, x -> fadd x, x transformation, since if it occurs
8141 // during an early run of DAGCombiner can prevent folding with fmuls
8142 // inserted during lowering.
8143 if (N0.getOpcode() == ISD::FADD && N0.getOperand(0) == N0.getOperand(1)) {
8144 const SDValue Two = DAG.getConstantFP(2.0, DL, VT);
8145 SDValue MulConsts = DAG.getNode(ISD::FMUL, DL, VT, Two, N1);
8146 return DAG.getNode(ISD::FMUL, DL, VT, N0.getOperand(0), MulConsts);
8150 // fold (fmul X, 2.0) -> (fadd X, X)
8151 if (N1CFP && N1CFP->isExactlyValue(+2.0))
8152 return DAG.getNode(ISD::FADD, DL, VT, N0, N0);
8154 // fold (fmul X, -1.0) -> (fneg X)
8155 if (N1CFP && N1CFP->isExactlyValue(-1.0))
8156 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
8157 return DAG.getNode(ISD::FNEG, DL, VT, N0);
8159 // fold (fmul (fneg X), (fneg Y)) -> (fmul X, Y)
8160 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI, &Options)) {
8161 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI, &Options)) {
8162 // Both can be negated for free, check to see if at least one is cheaper
8164 if (LHSNeg == 2 || RHSNeg == 2)
8165 return DAG.getNode(ISD::FMUL, DL, VT,
8166 GetNegatedExpression(N0, DAG, LegalOperations),
8167 GetNegatedExpression(N1, DAG, LegalOperations));
8174 SDValue DAGCombiner::visitFMA(SDNode *N) {
8175 SDValue N0 = N->getOperand(0);
8176 SDValue N1 = N->getOperand(1);
8177 SDValue N2 = N->getOperand(2);
8178 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
8179 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
8180 EVT VT = N->getValueType(0);
8182 const TargetOptions &Options = DAG.getTarget().Options;
8184 // Constant fold FMA.
8185 if (isa<ConstantFPSDNode>(N0) &&
8186 isa<ConstantFPSDNode>(N1) &&
8187 isa<ConstantFPSDNode>(N2)) {
8188 return DAG.getNode(ISD::FMA, dl, VT, N0, N1, N2);
8191 if (Options.UnsafeFPMath) {
8192 if (N0CFP && N0CFP->isZero())
8194 if (N1CFP && N1CFP->isZero())
8197 if (N0CFP && N0CFP->isExactlyValue(1.0))
8198 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N1, N2);
8199 if (N1CFP && N1CFP->isExactlyValue(1.0))
8200 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0, N2);
8202 // Canonicalize (fma c, x, y) -> (fma x, c, y)
8203 if (N0CFP && !N1CFP)
8204 return DAG.getNode(ISD::FMA, SDLoc(N), VT, N1, N0, N2);
8206 // (fma x, c1, (fmul x, c2)) -> (fmul x, c1+c2)
8207 if (Options.UnsafeFPMath && N1CFP &&
8208 N2.getOpcode() == ISD::FMUL &&
8209 N0 == N2.getOperand(0) &&
8210 N2.getOperand(1).getOpcode() == ISD::ConstantFP) {
8211 return DAG.getNode(ISD::FMUL, dl, VT, N0,
8212 DAG.getNode(ISD::FADD, dl, VT, N1, N2.getOperand(1)));
8216 // (fma (fmul x, c1), c2, y) -> (fma x, c1*c2, y)
8217 if (Options.UnsafeFPMath &&
8218 N0.getOpcode() == ISD::FMUL && N1CFP &&
8219 N0.getOperand(1).getOpcode() == ISD::ConstantFP) {
8220 return DAG.getNode(ISD::FMA, dl, VT,
8222 DAG.getNode(ISD::FMUL, dl, VT, N1, N0.getOperand(1)),
8226 // (fma x, 1, y) -> (fadd x, y)
8227 // (fma x, -1, y) -> (fadd (fneg x), y)
8229 if (N1CFP->isExactlyValue(1.0))
8230 return DAG.getNode(ISD::FADD, dl, VT, N0, N2);
8232 if (N1CFP->isExactlyValue(-1.0) &&
8233 (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))) {
8234 SDValue RHSNeg = DAG.getNode(ISD::FNEG, dl, VT, N0);
8235 AddToWorklist(RHSNeg.getNode());
8236 return DAG.getNode(ISD::FADD, dl, VT, N2, RHSNeg);
8240 // (fma x, c, x) -> (fmul x, (c+1))
8241 if (Options.UnsafeFPMath && N1CFP && N0 == N2)
8242 return DAG.getNode(ISD::FMUL, dl, VT, N0,
8243 DAG.getNode(ISD::FADD, dl, VT,
8244 N1, DAG.getConstantFP(1.0, dl, VT)));
8246 // (fma x, c, (fneg x)) -> (fmul x, (c-1))
8247 if (Options.UnsafeFPMath && N1CFP &&
8248 N2.getOpcode() == ISD::FNEG && N2.getOperand(0) == N0)
8249 return DAG.getNode(ISD::FMUL, dl, VT, N0,
8250 DAG.getNode(ISD::FADD, dl, VT,
8251 N1, DAG.getConstantFP(-1.0, dl, VT)));
8257 SDValue DAGCombiner::visitFDIV(SDNode *N) {
8258 SDValue N0 = N->getOperand(0);
8259 SDValue N1 = N->getOperand(1);
8260 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
8261 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
8262 EVT VT = N->getValueType(0);
8264 const TargetOptions &Options = DAG.getTarget().Options;
8268 if (SDValue FoldedVOp = SimplifyVBinOp(N))
8271 // fold (fdiv c1, c2) -> c1/c2
8273 return DAG.getNode(ISD::FDIV, SDLoc(N), VT, N0, N1);
8275 if (Options.UnsafeFPMath) {
8276 // fold (fdiv X, c2) -> fmul X, 1/c2 if losing precision is acceptable.
8278 // Compute the reciprocal 1.0 / c2.
8279 APFloat N1APF = N1CFP->getValueAPF();
8280 APFloat Recip(N1APF.getSemantics(), 1); // 1.0
8281 APFloat::opStatus st = Recip.divide(N1APF, APFloat::rmNearestTiesToEven);
8282 // Only do the transform if the reciprocal is a legal fp immediate that
8283 // isn't too nasty (eg NaN, denormal, ...).
8284 if ((st == APFloat::opOK || st == APFloat::opInexact) && // Not too nasty
8285 (!LegalOperations ||
8286 // FIXME: custom lowering of ConstantFP might fail (see e.g. ARM
8287 // backend)... we should handle this gracefully after Legalize.
8288 // TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT) ||
8289 TLI.isOperationLegal(llvm::ISD::ConstantFP, VT) ||
8290 TLI.isFPImmLegal(Recip, VT)))
8291 return DAG.getNode(ISD::FMUL, DL, VT, N0,
8292 DAG.getConstantFP(Recip, DL, VT));
8295 // If this FDIV is part of a reciprocal square root, it may be folded
8296 // into a target-specific square root estimate instruction.
8297 if (N1.getOpcode() == ISD::FSQRT) {
8298 if (SDValue RV = BuildRsqrtEstimate(N1.getOperand(0))) {
8299 return DAG.getNode(ISD::FMUL, DL, VT, N0, RV);
8301 } else if (N1.getOpcode() == ISD::FP_EXTEND &&
8302 N1.getOperand(0).getOpcode() == ISD::FSQRT) {
8303 if (SDValue RV = BuildRsqrtEstimate(N1.getOperand(0).getOperand(0))) {
8304 RV = DAG.getNode(ISD::FP_EXTEND, SDLoc(N1), VT, RV);
8305 AddToWorklist(RV.getNode());
8306 return DAG.getNode(ISD::FMUL, DL, VT, N0, RV);
8308 } else if (N1.getOpcode() == ISD::FP_ROUND &&
8309 N1.getOperand(0).getOpcode() == ISD::FSQRT) {
8310 if (SDValue RV = BuildRsqrtEstimate(N1.getOperand(0).getOperand(0))) {
8311 RV = DAG.getNode(ISD::FP_ROUND, SDLoc(N1), VT, RV, N1.getOperand(1));
8312 AddToWorklist(RV.getNode());
8313 return DAG.getNode(ISD::FMUL, DL, VT, N0, RV);
8315 } else if (N1.getOpcode() == ISD::FMUL) {
8316 // Look through an FMUL. Even though this won't remove the FDIV directly,
8317 // it's still worthwhile to get rid of the FSQRT if possible.
8320 if (N1.getOperand(0).getOpcode() == ISD::FSQRT) {
8321 SqrtOp = N1.getOperand(0);
8322 OtherOp = N1.getOperand(1);
8323 } else if (N1.getOperand(1).getOpcode() == ISD::FSQRT) {
8324 SqrtOp = N1.getOperand(1);
8325 OtherOp = N1.getOperand(0);
8327 if (SqrtOp.getNode()) {
8328 // We found a FSQRT, so try to make this fold:
8329 // x / (y * sqrt(z)) -> x * (rsqrt(z) / y)
8330 if (SDValue RV = BuildRsqrtEstimate(SqrtOp.getOperand(0))) {
8331 RV = DAG.getNode(ISD::FDIV, SDLoc(N1), VT, RV, OtherOp);
8332 AddToWorklist(RV.getNode());
8333 return DAG.getNode(ISD::FMUL, DL, VT, N0, RV);
8338 // Fold into a reciprocal estimate and multiply instead of a real divide.
8339 if (SDValue RV = BuildReciprocalEstimate(N1)) {
8340 AddToWorklist(RV.getNode());
8341 return DAG.getNode(ISD::FMUL, DL, VT, N0, RV);
8345 // (fdiv (fneg X), (fneg Y)) -> (fdiv X, Y)
8346 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI, &Options)) {
8347 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI, &Options)) {
8348 // Both can be negated for free, check to see if at least one is cheaper
8350 if (LHSNeg == 2 || RHSNeg == 2)
8351 return DAG.getNode(ISD::FDIV, SDLoc(N), VT,
8352 GetNegatedExpression(N0, DAG, LegalOperations),
8353 GetNegatedExpression(N1, DAG, LegalOperations));
8357 // Combine multiple FDIVs with the same divisor into multiple FMULs by the
8359 // E.g., (a / D; b / D;) -> (recip = 1.0 / D; a * recip; b * recip)
8360 // Notice that this is not always beneficial. One reason is different target
8361 // may have different costs for FDIV and FMUL, so sometimes the cost of two
8362 // FDIVs may be lower than the cost of one FDIV and two FMULs. Another reason
8363 // is the critical path is increased from "one FDIV" to "one FDIV + one FMUL".
8364 if (Options.UnsafeFPMath) {
8365 // Skip if current node is a reciprocal.
8366 if (N0CFP && N0CFP->isExactlyValue(1.0))
8369 SmallVector<SDNode *, 4> Users;
8370 // Find all FDIV users of the same divisor.
8371 for (auto *U : N1->uses()) {
8372 if (U->getOpcode() == ISD::FDIV && U->getOperand(1) == N1)
8376 if (TLI.combineRepeatedFPDivisors(Users.size())) {
8377 SDValue FPOne = DAG.getConstantFP(1.0, DL, VT);
8378 SDValue Reciprocal = DAG.getNode(ISD::FDIV, DL, VT, FPOne, N1);
8380 // Dividend / Divisor -> Dividend * Reciprocal
8381 for (auto *U : Users) {
8382 SDValue Dividend = U->getOperand(0);
8383 if (Dividend != FPOne) {
8384 SDValue NewNode = DAG.getNode(ISD::FMUL, SDLoc(U), VT, Dividend,
8386 DAG.ReplaceAllUsesWith(U, NewNode.getNode());
8396 SDValue DAGCombiner::visitFREM(SDNode *N) {
8397 SDValue N0 = N->getOperand(0);
8398 SDValue N1 = N->getOperand(1);
8399 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
8400 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
8401 EVT VT = N->getValueType(0);
8403 // fold (frem c1, c2) -> fmod(c1,c2)
8405 return DAG.getNode(ISD::FREM, SDLoc(N), VT, N0, N1);
8410 SDValue DAGCombiner::visitFSQRT(SDNode *N) {
8411 if (DAG.getTarget().Options.UnsafeFPMath &&
8412 !TLI.isFsqrtCheap()) {
8413 // Compute this as X * (1/sqrt(X)) = X * (X ** -0.5)
8414 if (SDValue RV = BuildRsqrtEstimate(N->getOperand(0))) {
8415 EVT VT = RV.getValueType();
8417 RV = DAG.getNode(ISD::FMUL, DL, VT, N->getOperand(0), RV);
8418 AddToWorklist(RV.getNode());
8420 // Unfortunately, RV is now NaN if the input was exactly 0.
8421 // Select out this case and force the answer to 0.
8422 SDValue Zero = DAG.getConstantFP(0.0, DL, VT);
8424 DAG.getSetCC(DL, TLI.getSetCCResultType(*DAG.getContext(), VT),
8425 N->getOperand(0), Zero, ISD::SETEQ);
8426 AddToWorklist(ZeroCmp.getNode());
8427 AddToWorklist(RV.getNode());
8429 RV = DAG.getNode(VT.isVector() ? ISD::VSELECT : ISD::SELECT,
8430 DL, VT, ZeroCmp, Zero, RV);
8437 SDValue DAGCombiner::visitFCOPYSIGN(SDNode *N) {
8438 SDValue N0 = N->getOperand(0);
8439 SDValue N1 = N->getOperand(1);
8440 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
8441 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
8442 EVT VT = N->getValueType(0);
8444 if (N0CFP && N1CFP) // Constant fold
8445 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT, N0, N1);
8448 const APFloat& V = N1CFP->getValueAPF();
8449 // copysign(x, c1) -> fabs(x) iff ispos(c1)
8450 // copysign(x, c1) -> fneg(fabs(x)) iff isneg(c1)
8451 if (!V.isNegative()) {
8452 if (!LegalOperations || TLI.isOperationLegal(ISD::FABS, VT))
8453 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
8455 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
8456 return DAG.getNode(ISD::FNEG, SDLoc(N), VT,
8457 DAG.getNode(ISD::FABS, SDLoc(N0), VT, N0));
8461 // copysign(fabs(x), y) -> copysign(x, y)
8462 // copysign(fneg(x), y) -> copysign(x, y)
8463 // copysign(copysign(x,z), y) -> copysign(x, y)
8464 if (N0.getOpcode() == ISD::FABS || N0.getOpcode() == ISD::FNEG ||
8465 N0.getOpcode() == ISD::FCOPYSIGN)
8466 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
8467 N0.getOperand(0), N1);
8469 // copysign(x, abs(y)) -> abs(x)
8470 if (N1.getOpcode() == ISD::FABS)
8471 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
8473 // copysign(x, copysign(y,z)) -> copysign(x, z)
8474 if (N1.getOpcode() == ISD::FCOPYSIGN)
8475 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
8476 N0, N1.getOperand(1));
8478 // copysign(x, fp_extend(y)) -> copysign(x, y)
8479 // copysign(x, fp_round(y)) -> copysign(x, y)
8480 if (N1.getOpcode() == ISD::FP_EXTEND || N1.getOpcode() == ISD::FP_ROUND)
8481 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
8482 N0, N1.getOperand(0));
8487 SDValue DAGCombiner::visitSINT_TO_FP(SDNode *N) {
8488 SDValue N0 = N->getOperand(0);
8489 EVT VT = N->getValueType(0);
8490 EVT OpVT = N0.getValueType();
8492 // fold (sint_to_fp c1) -> c1fp
8493 if (isConstantIntBuildVectorOrConstantInt(N0) &&
8494 // ...but only if the target supports immediate floating-point values
8495 (!LegalOperations ||
8496 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT)))
8497 return DAG.getNode(ISD::SINT_TO_FP, SDLoc(N), VT, N0);
8499 // If the input is a legal type, and SINT_TO_FP is not legal on this target,
8500 // but UINT_TO_FP is legal on this target, try to convert.
8501 if (!TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT) &&
8502 TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT)) {
8503 // If the sign bit is known to be zero, we can change this to UINT_TO_FP.
8504 if (DAG.SignBitIsZero(N0))
8505 return DAG.getNode(ISD::UINT_TO_FP, SDLoc(N), VT, N0);
8508 // The next optimizations are desirable only if SELECT_CC can be lowered.
8509 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT) || !LegalOperations) {
8510 // fold (sint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
8511 if (N0.getOpcode() == ISD::SETCC && N0.getValueType() == MVT::i1 &&
8513 (!LegalOperations ||
8514 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
8517 { N0.getOperand(0), N0.getOperand(1),
8518 DAG.getConstantFP(-1.0, DL, VT), DAG.getConstantFP(0.0, DL, VT),
8520 return DAG.getNode(ISD::SELECT_CC, DL, VT, Ops);
8523 // fold (sint_to_fp (zext (setcc x, y, cc))) ->
8524 // (select_cc x, y, 1.0, 0.0,, cc)
8525 if (N0.getOpcode() == ISD::ZERO_EXTEND &&
8526 N0.getOperand(0).getOpcode() == ISD::SETCC &&!VT.isVector() &&
8527 (!LegalOperations ||
8528 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
8531 { N0.getOperand(0).getOperand(0), N0.getOperand(0).getOperand(1),
8532 DAG.getConstantFP(1.0, DL, VT), DAG.getConstantFP(0.0, DL, VT),
8533 N0.getOperand(0).getOperand(2) };
8534 return DAG.getNode(ISD::SELECT_CC, DL, VT, Ops);
8541 SDValue DAGCombiner::visitUINT_TO_FP(SDNode *N) {
8542 SDValue N0 = N->getOperand(0);
8543 EVT VT = N->getValueType(0);
8544 EVT OpVT = N0.getValueType();
8546 // fold (uint_to_fp c1) -> c1fp
8547 if (isConstantIntBuildVectorOrConstantInt(N0) &&
8548 // ...but only if the target supports immediate floating-point values
8549 (!LegalOperations ||
8550 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT)))
8551 return DAG.getNode(ISD::UINT_TO_FP, SDLoc(N), VT, N0);
8553 // If the input is a legal type, and UINT_TO_FP is not legal on this target,
8554 // but SINT_TO_FP is legal on this target, try to convert.
8555 if (!TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT) &&
8556 TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT)) {
8557 // If the sign bit is known to be zero, we can change this to SINT_TO_FP.
8558 if (DAG.SignBitIsZero(N0))
8559 return DAG.getNode(ISD::SINT_TO_FP, SDLoc(N), VT, N0);
8562 // The next optimizations are desirable only if SELECT_CC can be lowered.
8563 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT) || !LegalOperations) {
8564 // fold (uint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
8566 if (N0.getOpcode() == ISD::SETCC && !VT.isVector() &&
8567 (!LegalOperations ||
8568 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
8571 { N0.getOperand(0), N0.getOperand(1),
8572 DAG.getConstantFP(1.0, DL, VT), DAG.getConstantFP(0.0, DL, VT),
8574 return DAG.getNode(ISD::SELECT_CC, DL, VT, Ops);
8581 // Fold (fp_to_{s/u}int ({s/u}int_to_fpx)) -> zext x, sext x, trunc x, or x
8582 static SDValue FoldIntToFPToInt(SDNode *N, SelectionDAG &DAG) {
8583 SDValue N0 = N->getOperand(0);
8584 EVT VT = N->getValueType(0);
8586 if (N0.getOpcode() != ISD::UINT_TO_FP && N0.getOpcode() != ISD::SINT_TO_FP)
8589 SDValue Src = N0.getOperand(0);
8590 EVT SrcVT = Src.getValueType();
8591 bool IsInputSigned = N0.getOpcode() == ISD::SINT_TO_FP;
8592 bool IsOutputSigned = N->getOpcode() == ISD::FP_TO_SINT;
8594 // We can safely assume the conversion won't overflow the output range,
8595 // because (for example) (uint8_t)18293.f is undefined behavior.
8597 // Since we can assume the conversion won't overflow, our decision as to
8598 // whether the input will fit in the float should depend on the minimum
8599 // of the input range and output range.
8601 // This means this is also safe for a signed input and unsigned output, since
8602 // a negative input would lead to undefined behavior.
8603 unsigned InputSize = (int)SrcVT.getScalarSizeInBits() - IsInputSigned;
8604 unsigned OutputSize = (int)VT.getScalarSizeInBits() - IsOutputSigned;
8605 unsigned ActualSize = std::min(InputSize, OutputSize);
8606 const fltSemantics &sem = DAG.EVTToAPFloatSemantics(N0.getValueType());
8608 // We can only fold away the float conversion if the input range can be
8609 // represented exactly in the float range.
8610 if (APFloat::semanticsPrecision(sem) >= ActualSize) {
8611 if (VT.getScalarSizeInBits() > SrcVT.getScalarSizeInBits()) {
8612 unsigned ExtOp = IsInputSigned && IsOutputSigned ? ISD::SIGN_EXTEND
8614 return DAG.getNode(ExtOp, SDLoc(N), VT, Src);
8616 if (VT.getScalarSizeInBits() < SrcVT.getScalarSizeInBits())
8617 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Src);
8620 return DAG.getNode(ISD::BITCAST, SDLoc(N), VT, Src);
8625 SDValue DAGCombiner::visitFP_TO_SINT(SDNode *N) {
8626 SDValue N0 = N->getOperand(0);
8627 EVT VT = N->getValueType(0);
8629 // fold (fp_to_sint c1fp) -> c1
8630 if (isConstantFPBuildVectorOrConstantFP(N0))
8631 return DAG.getNode(ISD::FP_TO_SINT, SDLoc(N), VT, N0);
8633 return FoldIntToFPToInt(N, DAG);
8636 SDValue DAGCombiner::visitFP_TO_UINT(SDNode *N) {
8637 SDValue N0 = N->getOperand(0);
8638 EVT VT = N->getValueType(0);
8640 // fold (fp_to_uint c1fp) -> c1
8641 if (isConstantFPBuildVectorOrConstantFP(N0))
8642 return DAG.getNode(ISD::FP_TO_UINT, SDLoc(N), VT, N0);
8644 return FoldIntToFPToInt(N, DAG);
8647 SDValue DAGCombiner::visitFP_ROUND(SDNode *N) {
8648 SDValue N0 = N->getOperand(0);
8649 SDValue N1 = N->getOperand(1);
8650 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
8651 EVT VT = N->getValueType(0);
8653 // fold (fp_round c1fp) -> c1fp
8655 return DAG.getNode(ISD::FP_ROUND, SDLoc(N), VT, N0, N1);
8657 // fold (fp_round (fp_extend x)) -> x
8658 if (N0.getOpcode() == ISD::FP_EXTEND && VT == N0.getOperand(0).getValueType())
8659 return N0.getOperand(0);
8661 // fold (fp_round (fp_round x)) -> (fp_round x)
8662 if (N0.getOpcode() == ISD::FP_ROUND) {
8663 const bool NIsTrunc = N->getConstantOperandVal(1) == 1;
8664 const bool N0IsTrunc = N0.getNode()->getConstantOperandVal(1) == 1;
8665 // If the first fp_round isn't a value preserving truncation, it might
8666 // introduce a tie in the second fp_round, that wouldn't occur in the
8667 // single-step fp_round we want to fold to.
8668 // In other words, double rounding isn't the same as rounding.
8669 // Also, this is a value preserving truncation iff both fp_round's are.
8670 if (DAG.getTarget().Options.UnsafeFPMath || N0IsTrunc) {
8672 return DAG.getNode(ISD::FP_ROUND, DL, VT, N0.getOperand(0),
8673 DAG.getIntPtrConstant(NIsTrunc && N0IsTrunc, DL));
8677 // fold (fp_round (copysign X, Y)) -> (copysign (fp_round X), Y)
8678 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse()) {
8679 SDValue Tmp = DAG.getNode(ISD::FP_ROUND, SDLoc(N0), VT,
8680 N0.getOperand(0), N1);
8681 AddToWorklist(Tmp.getNode());
8682 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
8683 Tmp, N0.getOperand(1));
8689 SDValue DAGCombiner::visitFP_ROUND_INREG(SDNode *N) {
8690 SDValue N0 = N->getOperand(0);
8691 EVT VT = N->getValueType(0);
8692 EVT EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
8693 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
8695 // fold (fp_round_inreg c1fp) -> c1fp
8696 if (N0CFP && isTypeLegal(EVT)) {
8698 SDValue Round = DAG.getConstantFP(*N0CFP->getConstantFPValue(), DL, EVT);
8699 return DAG.getNode(ISD::FP_EXTEND, DL, VT, Round);
8705 SDValue DAGCombiner::visitFP_EXTEND(SDNode *N) {
8706 SDValue N0 = N->getOperand(0);
8707 EVT VT = N->getValueType(0);
8709 // If this is fp_round(fpextend), don't fold it, allow ourselves to be folded.
8710 if (N->hasOneUse() &&
8711 N->use_begin()->getOpcode() == ISD::FP_ROUND)
8714 // fold (fp_extend c1fp) -> c1fp
8715 if (isConstantFPBuildVectorOrConstantFP(N0))
8716 return DAG.getNode(ISD::FP_EXTEND, SDLoc(N), VT, N0);
8718 // fold (fp_extend (fp16_to_fp op)) -> (fp16_to_fp op)
8719 if (N0.getOpcode() == ISD::FP16_TO_FP &&
8720 TLI.getOperationAction(ISD::FP16_TO_FP, VT) == TargetLowering::Legal)
8721 return DAG.getNode(ISD::FP16_TO_FP, SDLoc(N), VT, N0.getOperand(0));
8723 // Turn fp_extend(fp_round(X, 1)) -> x since the fp_round doesn't affect the
8725 if (N0.getOpcode() == ISD::FP_ROUND
8726 && N0.getNode()->getConstantOperandVal(1) == 1) {
8727 SDValue In = N0.getOperand(0);
8728 if (In.getValueType() == VT) return In;
8729 if (VT.bitsLT(In.getValueType()))
8730 return DAG.getNode(ISD::FP_ROUND, SDLoc(N), VT,
8731 In, N0.getOperand(1));
8732 return DAG.getNode(ISD::FP_EXTEND, SDLoc(N), VT, In);
8735 // fold (fpext (load x)) -> (fpext (fptrunc (extload x)))
8736 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
8737 TLI.isLoadExtLegal(ISD::EXTLOAD, VT, N0.getValueType())) {
8738 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
8739 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, SDLoc(N), VT,
8741 LN0->getBasePtr(), N0.getValueType(),
8742 LN0->getMemOperand());
8743 CombineTo(N, ExtLoad);
8744 CombineTo(N0.getNode(),
8745 DAG.getNode(ISD::FP_ROUND, SDLoc(N0),
8746 N0.getValueType(), ExtLoad,
8747 DAG.getIntPtrConstant(1, SDLoc(N0))),
8748 ExtLoad.getValue(1));
8749 return SDValue(N, 0); // Return N so it doesn't get rechecked!
8755 SDValue DAGCombiner::visitFCEIL(SDNode *N) {
8756 SDValue N0 = N->getOperand(0);
8757 EVT VT = N->getValueType(0);
8759 // fold (fceil c1) -> fceil(c1)
8760 if (isConstantFPBuildVectorOrConstantFP(N0))
8761 return DAG.getNode(ISD::FCEIL, SDLoc(N), VT, N0);
8766 SDValue DAGCombiner::visitFTRUNC(SDNode *N) {
8767 SDValue N0 = N->getOperand(0);
8768 EVT VT = N->getValueType(0);
8770 // fold (ftrunc c1) -> ftrunc(c1)
8771 if (isConstantFPBuildVectorOrConstantFP(N0))
8772 return DAG.getNode(ISD::FTRUNC, SDLoc(N), VT, N0);
8777 SDValue DAGCombiner::visitFFLOOR(SDNode *N) {
8778 SDValue N0 = N->getOperand(0);
8779 EVT VT = N->getValueType(0);
8781 // fold (ffloor c1) -> ffloor(c1)
8782 if (isConstantFPBuildVectorOrConstantFP(N0))
8783 return DAG.getNode(ISD::FFLOOR, SDLoc(N), VT, N0);
8788 // FIXME: FNEG and FABS have a lot in common; refactor.
8789 SDValue DAGCombiner::visitFNEG(SDNode *N) {
8790 SDValue N0 = N->getOperand(0);
8791 EVT VT = N->getValueType(0);
8793 // Constant fold FNEG.
8794 if (isConstantFPBuildVectorOrConstantFP(N0))
8795 return DAG.getNode(ISD::FNEG, SDLoc(N), VT, N0);
8797 if (isNegatibleForFree(N0, LegalOperations, DAG.getTargetLoweringInfo(),
8798 &DAG.getTarget().Options))
8799 return GetNegatedExpression(N0, DAG, LegalOperations);
8801 // Transform fneg(bitconvert(x)) -> bitconvert(x ^ sign) to avoid loading
8802 // constant pool values.
8803 if (!TLI.isFNegFree(VT) &&
8804 N0.getOpcode() == ISD::BITCAST &&
8805 N0.getNode()->hasOneUse()) {
8806 SDValue Int = N0.getOperand(0);
8807 EVT IntVT = Int.getValueType();
8808 if (IntVT.isInteger() && !IntVT.isVector()) {
8810 if (N0.getValueType().isVector()) {
8811 // For a vector, get a mask such as 0x80... per scalar element
8813 SignMask = APInt::getSignBit(N0.getValueType().getScalarSizeInBits());
8814 SignMask = APInt::getSplat(IntVT.getSizeInBits(), SignMask);
8816 // For a scalar, just generate 0x80...
8817 SignMask = APInt::getSignBit(IntVT.getSizeInBits());
8820 Int = DAG.getNode(ISD::XOR, DL0, IntVT, Int,
8821 DAG.getConstant(SignMask, DL0, IntVT));
8822 AddToWorklist(Int.getNode());
8823 return DAG.getNode(ISD::BITCAST, SDLoc(N), VT, Int);
8827 // (fneg (fmul c, x)) -> (fmul -c, x)
8828 if (N0.getOpcode() == ISD::FMUL &&
8829 (N0.getNode()->hasOneUse() || !TLI.isFNegFree(VT))) {
8830 ConstantFPSDNode *CFP1 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
8832 APFloat CVal = CFP1->getValueAPF();
8834 if (Level >= AfterLegalizeDAG &&
8835 (TLI.isFPImmLegal(CVal, N->getValueType(0)) ||
8836 TLI.isOperationLegal(ISD::ConstantFP, N->getValueType(0))))
8838 ISD::FMUL, SDLoc(N), VT, N0.getOperand(0),
8839 DAG.getNode(ISD::FNEG, SDLoc(N), VT, N0.getOperand(1)));
8846 SDValue DAGCombiner::visitFMINNUM(SDNode *N) {
8847 SDValue N0 = N->getOperand(0);
8848 SDValue N1 = N->getOperand(1);
8849 const ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
8850 const ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
8852 if (N0CFP && N1CFP) {
8853 const APFloat &C0 = N0CFP->getValueAPF();
8854 const APFloat &C1 = N1CFP->getValueAPF();
8855 return DAG.getConstantFP(minnum(C0, C1), SDLoc(N), N->getValueType(0));
8859 EVT VT = N->getValueType(0);
8860 // Canonicalize to constant on RHS.
8861 return DAG.getNode(ISD::FMINNUM, SDLoc(N), VT, N1, N0);
8867 SDValue DAGCombiner::visitFMAXNUM(SDNode *N) {
8868 SDValue N0 = N->getOperand(0);
8869 SDValue N1 = N->getOperand(1);
8870 const ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
8871 const ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
8873 if (N0CFP && N1CFP) {
8874 const APFloat &C0 = N0CFP->getValueAPF();
8875 const APFloat &C1 = N1CFP->getValueAPF();
8876 return DAG.getConstantFP(maxnum(C0, C1), SDLoc(N), N->getValueType(0));
8880 EVT VT = N->getValueType(0);
8881 // Canonicalize to constant on RHS.
8882 return DAG.getNode(ISD::FMAXNUM, SDLoc(N), VT, N1, N0);
8888 SDValue DAGCombiner::visitFABS(SDNode *N) {
8889 SDValue N0 = N->getOperand(0);
8890 EVT VT = N->getValueType(0);
8892 // fold (fabs c1) -> fabs(c1)
8893 if (isConstantFPBuildVectorOrConstantFP(N0))
8894 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
8896 // fold (fabs (fabs x)) -> (fabs x)
8897 if (N0.getOpcode() == ISD::FABS)
8898 return N->getOperand(0);
8900 // fold (fabs (fneg x)) -> (fabs x)
8901 // fold (fabs (fcopysign x, y)) -> (fabs x)
8902 if (N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FCOPYSIGN)
8903 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0.getOperand(0));
8905 // Transform fabs(bitconvert(x)) -> bitconvert(x & ~sign) to avoid loading
8906 // constant pool values.
8907 if (!TLI.isFAbsFree(VT) &&
8908 N0.getOpcode() == ISD::BITCAST &&
8909 N0.getNode()->hasOneUse()) {
8910 SDValue Int = N0.getOperand(0);
8911 EVT IntVT = Int.getValueType();
8912 if (IntVT.isInteger() && !IntVT.isVector()) {
8914 if (N0.getValueType().isVector()) {
8915 // For a vector, get a mask such as 0x7f... per scalar element
8917 SignMask = ~APInt::getSignBit(N0.getValueType().getScalarSizeInBits());
8918 SignMask = APInt::getSplat(IntVT.getSizeInBits(), SignMask);
8920 // For a scalar, just generate 0x7f...
8921 SignMask = ~APInt::getSignBit(IntVT.getSizeInBits());
8924 Int = DAG.getNode(ISD::AND, DL, IntVT, Int,
8925 DAG.getConstant(SignMask, DL, IntVT));
8926 AddToWorklist(Int.getNode());
8927 return DAG.getNode(ISD::BITCAST, SDLoc(N), N->getValueType(0), Int);
8934 SDValue DAGCombiner::visitBRCOND(SDNode *N) {
8935 SDValue Chain = N->getOperand(0);
8936 SDValue N1 = N->getOperand(1);
8937 SDValue N2 = N->getOperand(2);
8939 // If N is a constant we could fold this into a fallthrough or unconditional
8940 // branch. However that doesn't happen very often in normal code, because
8941 // Instcombine/SimplifyCFG should have handled the available opportunities.
8942 // If we did this folding here, it would be necessary to update the
8943 // MachineBasicBlock CFG, which is awkward.
8945 // fold a brcond with a setcc condition into a BR_CC node if BR_CC is legal
8947 if (N1.getOpcode() == ISD::SETCC &&
8948 TLI.isOperationLegalOrCustom(ISD::BR_CC,
8949 N1.getOperand(0).getValueType())) {
8950 return DAG.getNode(ISD::BR_CC, SDLoc(N), MVT::Other,
8951 Chain, N1.getOperand(2),
8952 N1.getOperand(0), N1.getOperand(1), N2);
8955 if ((N1.hasOneUse() && N1.getOpcode() == ISD::SRL) ||
8956 ((N1.getOpcode() == ISD::TRUNCATE && N1.hasOneUse()) &&
8957 (N1.getOperand(0).hasOneUse() &&
8958 N1.getOperand(0).getOpcode() == ISD::SRL))) {
8959 SDNode *Trunc = nullptr;
8960 if (N1.getOpcode() == ISD::TRUNCATE) {
8961 // Look pass the truncate.
8962 Trunc = N1.getNode();
8963 N1 = N1.getOperand(0);
8966 // Match this pattern so that we can generate simpler code:
8969 // %b = and i32 %a, 2
8970 // %c = srl i32 %b, 1
8971 // brcond i32 %c ...
8976 // %b = and i32 %a, 2
8977 // %c = setcc eq %b, 0
8980 // This applies only when the AND constant value has one bit set and the
8981 // SRL constant is equal to the log2 of the AND constant. The back-end is
8982 // smart enough to convert the result into a TEST/JMP sequence.
8983 SDValue Op0 = N1.getOperand(0);
8984 SDValue Op1 = N1.getOperand(1);
8986 if (Op0.getOpcode() == ISD::AND &&
8987 Op1.getOpcode() == ISD::Constant) {
8988 SDValue AndOp1 = Op0.getOperand(1);
8990 if (AndOp1.getOpcode() == ISD::Constant) {
8991 const APInt &AndConst = cast<ConstantSDNode>(AndOp1)->getAPIntValue();
8993 if (AndConst.isPowerOf2() &&
8994 cast<ConstantSDNode>(Op1)->getAPIntValue()==AndConst.logBase2()) {
8998 getSetCCResultType(Op0.getValueType()),
8999 Op0, DAG.getConstant(0, DL, Op0.getValueType()),
9002 SDValue NewBRCond = DAG.getNode(ISD::BRCOND, DL,
9003 MVT::Other, Chain, SetCC, N2);
9004 // Don't add the new BRCond into the worklist or else SimplifySelectCC
9005 // will convert it back to (X & C1) >> C2.
9006 CombineTo(N, NewBRCond, false);
9007 // Truncate is dead.
9009 deleteAndRecombine(Trunc);
9010 // Replace the uses of SRL with SETCC
9011 WorklistRemover DeadNodes(*this);
9012 DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
9013 deleteAndRecombine(N1.getNode());
9014 return SDValue(N, 0); // Return N so it doesn't get rechecked!
9020 // Restore N1 if the above transformation doesn't match.
9021 N1 = N->getOperand(1);
9024 // Transform br(xor(x, y)) -> br(x != y)
9025 // Transform br(xor(xor(x,y), 1)) -> br (x == y)
9026 if (N1.hasOneUse() && N1.getOpcode() == ISD::XOR) {
9027 SDNode *TheXor = N1.getNode();
9028 SDValue Op0 = TheXor->getOperand(0);
9029 SDValue Op1 = TheXor->getOperand(1);
9030 if (Op0.getOpcode() == Op1.getOpcode()) {
9031 // Avoid missing important xor optimizations.
9032 SDValue Tmp = visitXOR(TheXor);
9033 if (Tmp.getNode()) {
9034 if (Tmp.getNode() != TheXor) {
9035 DEBUG(dbgs() << "\nReplacing.8 ";
9037 dbgs() << "\nWith: ";
9038 Tmp.getNode()->dump(&DAG);
9040 WorklistRemover DeadNodes(*this);
9041 DAG.ReplaceAllUsesOfValueWith(N1, Tmp);
9042 deleteAndRecombine(TheXor);
9043 return DAG.getNode(ISD::BRCOND, SDLoc(N),
9044 MVT::Other, Chain, Tmp, N2);
9047 // visitXOR has changed XOR's operands or replaced the XOR completely,
9049 return SDValue(N, 0);
9053 if (Op0.getOpcode() != ISD::SETCC && Op1.getOpcode() != ISD::SETCC) {
9055 if (isOneConstant(Op0) && Op0.hasOneUse() &&
9056 Op0.getOpcode() == ISD::XOR) {
9057 TheXor = Op0.getNode();
9061 EVT SetCCVT = N1.getValueType();
9063 SetCCVT = getSetCCResultType(SetCCVT);
9064 SDValue SetCC = DAG.getSetCC(SDLoc(TheXor),
9067 Equal ? ISD::SETEQ : ISD::SETNE);
9068 // Replace the uses of XOR with SETCC
9069 WorklistRemover DeadNodes(*this);
9070 DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
9071 deleteAndRecombine(N1.getNode());
9072 return DAG.getNode(ISD::BRCOND, SDLoc(N),
9073 MVT::Other, Chain, SetCC, N2);
9080 // Operand List for BR_CC: Chain, CondCC, CondLHS, CondRHS, DestBB.
9082 SDValue DAGCombiner::visitBR_CC(SDNode *N) {
9083 CondCodeSDNode *CC = cast<CondCodeSDNode>(N->getOperand(1));
9084 SDValue CondLHS = N->getOperand(2), CondRHS = N->getOperand(3);
9086 // If N is a constant we could fold this into a fallthrough or unconditional
9087 // branch. However that doesn't happen very often in normal code, because
9088 // Instcombine/SimplifyCFG should have handled the available opportunities.
9089 // If we did this folding here, it would be necessary to update the
9090 // MachineBasicBlock CFG, which is awkward.
9092 // Use SimplifySetCC to simplify SETCC's.
9093 SDValue Simp = SimplifySetCC(getSetCCResultType(CondLHS.getValueType()),
9094 CondLHS, CondRHS, CC->get(), SDLoc(N),
9096 if (Simp.getNode()) AddToWorklist(Simp.getNode());
9098 // fold to a simpler setcc
9099 if (Simp.getNode() && Simp.getOpcode() == ISD::SETCC)
9100 return DAG.getNode(ISD::BR_CC, SDLoc(N), MVT::Other,
9101 N->getOperand(0), Simp.getOperand(2),
9102 Simp.getOperand(0), Simp.getOperand(1),
9108 /// Return true if 'Use' is a load or a store that uses N as its base pointer
9109 /// and that N may be folded in the load / store addressing mode.
9110 static bool canFoldInAddressingMode(SDNode *N, SDNode *Use,
9112 const TargetLowering &TLI) {
9116 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Use)) {
9117 if (LD->isIndexed() || LD->getBasePtr().getNode() != N)
9119 VT = LD->getMemoryVT();
9120 AS = LD->getAddressSpace();
9121 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(Use)) {
9122 if (ST->isIndexed() || ST->getBasePtr().getNode() != N)
9124 VT = ST->getMemoryVT();
9125 AS = ST->getAddressSpace();
9129 TargetLowering::AddrMode AM;
9130 if (N->getOpcode() == ISD::ADD) {
9131 ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
9134 AM.BaseOffs = Offset->getSExtValue();
9138 } else if (N->getOpcode() == ISD::SUB) {
9139 ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
9142 AM.BaseOffs = -Offset->getSExtValue();
9149 return TLI.isLegalAddressingMode(AM, VT.getTypeForEVT(*DAG.getContext()), AS);
9152 /// Try turning a load/store into a pre-indexed load/store when the base
9153 /// pointer is an add or subtract and it has other uses besides the load/store.
9154 /// After the transformation, the new indexed load/store has effectively folded
9155 /// the add/subtract in and all of its other uses are redirected to the
9157 bool DAGCombiner::CombineToPreIndexedLoadStore(SDNode *N) {
9158 if (Level < AfterLegalizeDAG)
9164 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
9165 if (LD->isIndexed())
9167 VT = LD->getMemoryVT();
9168 if (!TLI.isIndexedLoadLegal(ISD::PRE_INC, VT) &&
9169 !TLI.isIndexedLoadLegal(ISD::PRE_DEC, VT))
9171 Ptr = LD->getBasePtr();
9172 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
9173 if (ST->isIndexed())
9175 VT = ST->getMemoryVT();
9176 if (!TLI.isIndexedStoreLegal(ISD::PRE_INC, VT) &&
9177 !TLI.isIndexedStoreLegal(ISD::PRE_DEC, VT))
9179 Ptr = ST->getBasePtr();
9185 // If the pointer is not an add/sub, or if it doesn't have multiple uses, bail
9186 // out. There is no reason to make this a preinc/predec.
9187 if ((Ptr.getOpcode() != ISD::ADD && Ptr.getOpcode() != ISD::SUB) ||
9188 Ptr.getNode()->hasOneUse())
9191 // Ask the target to do addressing mode selection.
9194 ISD::MemIndexedMode AM = ISD::UNINDEXED;
9195 if (!TLI.getPreIndexedAddressParts(N, BasePtr, Offset, AM, DAG))
9198 // Backends without true r+i pre-indexed forms may need to pass a
9199 // constant base with a variable offset so that constant coercion
9200 // will work with the patterns in canonical form.
9201 bool Swapped = false;
9202 if (isa<ConstantSDNode>(BasePtr)) {
9203 std::swap(BasePtr, Offset);
9207 // Don't create a indexed load / store with zero offset.
9208 if (isNullConstant(Offset))
9211 // Try turning it into a pre-indexed load / store except when:
9212 // 1) The new base ptr is a frame index.
9213 // 2) If N is a store and the new base ptr is either the same as or is a
9214 // predecessor of the value being stored.
9215 // 3) Another use of old base ptr is a predecessor of N. If ptr is folded
9216 // that would create a cycle.
9217 // 4) All uses are load / store ops that use it as old base ptr.
9219 // Check #1. Preinc'ing a frame index would require copying the stack pointer
9220 // (plus the implicit offset) to a register to preinc anyway.
9221 if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
9226 SDValue Val = cast<StoreSDNode>(N)->getValue();
9227 if (Val == BasePtr || BasePtr.getNode()->isPredecessorOf(Val.getNode()))
9231 // If the offset is a constant, there may be other adds of constants that
9232 // can be folded with this one. We should do this to avoid having to keep
9233 // a copy of the original base pointer.
9234 SmallVector<SDNode *, 16> OtherUses;
9235 if (isa<ConstantSDNode>(Offset))
9236 for (SDNode::use_iterator UI = BasePtr.getNode()->use_begin(),
9237 UE = BasePtr.getNode()->use_end();
9239 SDUse &Use = UI.getUse();
9240 // Skip the use that is Ptr and uses of other results from BasePtr's
9241 // node (important for nodes that return multiple results).
9242 if (Use.getUser() == Ptr.getNode() || Use != BasePtr)
9245 if (Use.getUser()->isPredecessorOf(N))
9248 if (Use.getUser()->getOpcode() != ISD::ADD &&
9249 Use.getUser()->getOpcode() != ISD::SUB) {
9254 SDValue Op1 = Use.getUser()->getOperand((UI.getOperandNo() + 1) & 1);
9255 if (!isa<ConstantSDNode>(Op1)) {
9260 // FIXME: In some cases, we can be smarter about this.
9261 if (Op1.getValueType() != Offset.getValueType()) {
9266 OtherUses.push_back(Use.getUser());
9270 std::swap(BasePtr, Offset);
9272 // Now check for #3 and #4.
9273 bool RealUse = false;
9275 // Caches for hasPredecessorHelper
9276 SmallPtrSet<const SDNode *, 32> Visited;
9277 SmallVector<const SDNode *, 16> Worklist;
9279 for (SDNode *Use : Ptr.getNode()->uses()) {
9282 if (N->hasPredecessorHelper(Use, Visited, Worklist))
9285 // If Ptr may be folded in addressing mode of other use, then it's
9286 // not profitable to do this transformation.
9287 if (!canFoldInAddressingMode(Ptr.getNode(), Use, DAG, TLI))
9296 Result = DAG.getIndexedLoad(SDValue(N,0), SDLoc(N),
9297 BasePtr, Offset, AM);
9299 Result = DAG.getIndexedStore(SDValue(N,0), SDLoc(N),
9300 BasePtr, Offset, AM);
9303 DEBUG(dbgs() << "\nReplacing.4 ";
9305 dbgs() << "\nWith: ";
9306 Result.getNode()->dump(&DAG);
9308 WorklistRemover DeadNodes(*this);
9310 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
9311 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
9313 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
9316 // Finally, since the node is now dead, remove it from the graph.
9317 deleteAndRecombine(N);
9320 std::swap(BasePtr, Offset);
9322 // Replace other uses of BasePtr that can be updated to use Ptr
9323 for (unsigned i = 0, e = OtherUses.size(); i != e; ++i) {
9324 unsigned OffsetIdx = 1;
9325 if (OtherUses[i]->getOperand(OffsetIdx).getNode() == BasePtr.getNode())
9327 assert(OtherUses[i]->getOperand(!OffsetIdx).getNode() ==
9328 BasePtr.getNode() && "Expected BasePtr operand");
9330 // We need to replace ptr0 in the following expression:
9331 // x0 * offset0 + y0 * ptr0 = t0
9333 // x1 * offset1 + y1 * ptr0 = t1 (the indexed load/store)
9335 // where x0, x1, y0 and y1 in {-1, 1} are given by the types of the
9336 // indexed load/store and the expresion that needs to be re-written.
9338 // Therefore, we have:
9339 // t0 = (x0 * offset0 - x1 * y0 * y1 *offset1) + (y0 * y1) * t1
9341 ConstantSDNode *CN =
9342 cast<ConstantSDNode>(OtherUses[i]->getOperand(OffsetIdx));
9344 APInt Offset0 = CN->getAPIntValue();
9345 APInt Offset1 = cast<ConstantSDNode>(Offset)->getAPIntValue();
9347 X0 = (OtherUses[i]->getOpcode() == ISD::SUB && OffsetIdx == 1) ? -1 : 1;
9348 Y0 = (OtherUses[i]->getOpcode() == ISD::SUB && OffsetIdx == 0) ? -1 : 1;
9349 X1 = (AM == ISD::PRE_DEC && !Swapped) ? -1 : 1;
9350 Y1 = (AM == ISD::PRE_DEC && Swapped) ? -1 : 1;
9352 unsigned Opcode = (Y0 * Y1 < 0) ? ISD::SUB : ISD::ADD;
9354 APInt CNV = Offset0;
9355 if (X0 < 0) CNV = -CNV;
9356 if (X1 * Y0 * Y1 < 0) CNV = CNV + Offset1;
9357 else CNV = CNV - Offset1;
9359 SDLoc DL(OtherUses[i]);
9361 // We can now generate the new expression.
9362 SDValue NewOp1 = DAG.getConstant(CNV, DL, CN->getValueType(0));
9363 SDValue NewOp2 = Result.getValue(isLoad ? 1 : 0);
9365 SDValue NewUse = DAG.getNode(Opcode,
9367 OtherUses[i]->getValueType(0), NewOp1, NewOp2);
9368 DAG.ReplaceAllUsesOfValueWith(SDValue(OtherUses[i], 0), NewUse);
9369 deleteAndRecombine(OtherUses[i]);
9372 // Replace the uses of Ptr with uses of the updated base value.
9373 DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0));
9374 deleteAndRecombine(Ptr.getNode());
9379 /// Try to combine a load/store with a add/sub of the base pointer node into a
9380 /// post-indexed load/store. The transformation folded the add/subtract into the
9381 /// new indexed load/store effectively and all of its uses are redirected to the
9383 bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
9384 if (Level < AfterLegalizeDAG)
9390 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
9391 if (LD->isIndexed())
9393 VT = LD->getMemoryVT();
9394 if (!TLI.isIndexedLoadLegal(ISD::POST_INC, VT) &&
9395 !TLI.isIndexedLoadLegal(ISD::POST_DEC, VT))
9397 Ptr = LD->getBasePtr();
9398 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
9399 if (ST->isIndexed())
9401 VT = ST->getMemoryVT();
9402 if (!TLI.isIndexedStoreLegal(ISD::POST_INC, VT) &&
9403 !TLI.isIndexedStoreLegal(ISD::POST_DEC, VT))
9405 Ptr = ST->getBasePtr();
9411 if (Ptr.getNode()->hasOneUse())
9414 for (SDNode *Op : Ptr.getNode()->uses()) {
9416 (Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB))
9421 ISD::MemIndexedMode AM = ISD::UNINDEXED;
9422 if (TLI.getPostIndexedAddressParts(N, Op, BasePtr, Offset, AM, DAG)) {
9423 // Don't create a indexed load / store with zero offset.
9424 if (isNullConstant(Offset))
9427 // Try turning it into a post-indexed load / store except when
9428 // 1) All uses are load / store ops that use it as base ptr (and
9429 // it may be folded as addressing mmode).
9430 // 2) Op must be independent of N, i.e. Op is neither a predecessor
9431 // nor a successor of N. Otherwise, if Op is folded that would
9434 if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
9438 bool TryNext = false;
9439 for (SDNode *Use : BasePtr.getNode()->uses()) {
9440 if (Use == Ptr.getNode())
9443 // If all the uses are load / store addresses, then don't do the
9445 if (Use->getOpcode() == ISD::ADD || Use->getOpcode() == ISD::SUB){
9446 bool RealUse = false;
9447 for (SDNode *UseUse : Use->uses()) {
9448 if (!canFoldInAddressingMode(Use, UseUse, DAG, TLI))
9463 if (!Op->isPredecessorOf(N) && !N->isPredecessorOf(Op)) {
9464 SDValue Result = isLoad
9465 ? DAG.getIndexedLoad(SDValue(N,0), SDLoc(N),
9466 BasePtr, Offset, AM)
9467 : DAG.getIndexedStore(SDValue(N,0), SDLoc(N),
9468 BasePtr, Offset, AM);
9471 DEBUG(dbgs() << "\nReplacing.5 ";
9473 dbgs() << "\nWith: ";
9474 Result.getNode()->dump(&DAG);
9476 WorklistRemover DeadNodes(*this);
9478 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
9479 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
9481 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
9484 // Finally, since the node is now dead, remove it from the graph.
9485 deleteAndRecombine(N);
9487 // Replace the uses of Use with uses of the updated base value.
9488 DAG.ReplaceAllUsesOfValueWith(SDValue(Op, 0),
9489 Result.getValue(isLoad ? 1 : 0));
9490 deleteAndRecombine(Op);
9499 /// \brief Return the base-pointer arithmetic from an indexed \p LD.
9500 SDValue DAGCombiner::SplitIndexingFromLoad(LoadSDNode *LD) {
9501 ISD::MemIndexedMode AM = LD->getAddressingMode();
9502 assert(AM != ISD::UNINDEXED);
9503 SDValue BP = LD->getOperand(1);
9504 SDValue Inc = LD->getOperand(2);
9506 // Some backends use TargetConstants for load offsets, but don't expect
9507 // TargetConstants in general ADD nodes. We can convert these constants into
9508 // regular Constants (if the constant is not opaque).
9509 assert((Inc.getOpcode() != ISD::TargetConstant ||
9510 !cast<ConstantSDNode>(Inc)->isOpaque()) &&
9511 "Cannot split out indexing using opaque target constants");
9512 if (Inc.getOpcode() == ISD::TargetConstant) {
9513 ConstantSDNode *ConstInc = cast<ConstantSDNode>(Inc);
9514 Inc = DAG.getConstant(*ConstInc->getConstantIntValue(), SDLoc(Inc),
9515 ConstInc->getValueType(0));
9519 (AM == ISD::PRE_INC || AM == ISD::POST_INC ? ISD::ADD : ISD::SUB);
9520 return DAG.getNode(Opc, SDLoc(LD), BP.getSimpleValueType(), BP, Inc);
9523 SDValue DAGCombiner::visitLOAD(SDNode *N) {
9524 LoadSDNode *LD = cast<LoadSDNode>(N);
9525 SDValue Chain = LD->getChain();
9526 SDValue Ptr = LD->getBasePtr();
9528 // If load is not volatile and there are no uses of the loaded value (and
9529 // the updated indexed value in case of indexed loads), change uses of the
9530 // chain value into uses of the chain input (i.e. delete the dead load).
9531 if (!LD->isVolatile()) {
9532 if (N->getValueType(1) == MVT::Other) {
9534 if (!N->hasAnyUseOfValue(0)) {
9535 // It's not safe to use the two value CombineTo variant here. e.g.
9536 // v1, chain2 = load chain1, loc
9537 // v2, chain3 = load chain2, loc
9539 // Now we replace use of chain2 with chain1. This makes the second load
9540 // isomorphic to the one we are deleting, and thus makes this load live.
9541 DEBUG(dbgs() << "\nReplacing.6 ";
9543 dbgs() << "\nWith chain: ";
9544 Chain.getNode()->dump(&DAG);
9546 WorklistRemover DeadNodes(*this);
9547 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain);
9550 deleteAndRecombine(N);
9552 return SDValue(N, 0); // Return N so it doesn't get rechecked!
9556 assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?");
9558 // If this load has an opaque TargetConstant offset, then we cannot split
9559 // the indexing into an add/sub directly (that TargetConstant may not be
9560 // valid for a different type of node, and we cannot convert an opaque
9561 // target constant into a regular constant).
9562 bool HasOTCInc = LD->getOperand(2).getOpcode() == ISD::TargetConstant &&
9563 cast<ConstantSDNode>(LD->getOperand(2))->isOpaque();
9565 if (!N->hasAnyUseOfValue(0) &&
9566 ((MaySplitLoadIndex && !HasOTCInc) || !N->hasAnyUseOfValue(1))) {
9567 SDValue Undef = DAG.getUNDEF(N->getValueType(0));
9569 if (N->hasAnyUseOfValue(1) && MaySplitLoadIndex && !HasOTCInc) {
9570 Index = SplitIndexingFromLoad(LD);
9571 // Try to fold the base pointer arithmetic into subsequent loads and
9573 AddUsersToWorklist(N);
9575 Index = DAG.getUNDEF(N->getValueType(1));
9576 DEBUG(dbgs() << "\nReplacing.7 ";
9578 dbgs() << "\nWith: ";
9579 Undef.getNode()->dump(&DAG);
9580 dbgs() << " and 2 other values\n");
9581 WorklistRemover DeadNodes(*this);
9582 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Undef);
9583 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Index);
9584 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 2), Chain);
9585 deleteAndRecombine(N);
9586 return SDValue(N, 0); // Return N so it doesn't get rechecked!
9591 // If this load is directly stored, replace the load value with the stored
9593 // TODO: Handle store large -> read small portion.
9594 // TODO: Handle TRUNCSTORE/LOADEXT
9595 if (ISD::isNormalLoad(N) && !LD->isVolatile()) {
9596 if (ISD::isNON_TRUNCStore(Chain.getNode())) {
9597 StoreSDNode *PrevST = cast<StoreSDNode>(Chain);
9598 if (PrevST->getBasePtr() == Ptr &&
9599 PrevST->getValue().getValueType() == N->getValueType(0))
9600 return CombineTo(N, Chain.getOperand(1), Chain);
9604 // Try to infer better alignment information than the load already has.
9605 if (OptLevel != CodeGenOpt::None && LD->isUnindexed()) {
9606 if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
9607 if (Align > LD->getMemOperand()->getBaseAlignment()) {
9609 DAG.getExtLoad(LD->getExtensionType(), SDLoc(N),
9610 LD->getValueType(0),
9611 Chain, Ptr, LD->getPointerInfo(),
9613 LD->isVolatile(), LD->isNonTemporal(),
9614 LD->isInvariant(), Align, LD->getAAInfo());
9615 if (NewLoad.getNode() != N)
9616 return CombineTo(N, NewLoad, SDValue(NewLoad.getNode(), 1), true);
9621 bool UseAA = CombinerAA.getNumOccurrences() > 0 ? CombinerAA
9622 : DAG.getSubtarget().useAA();
9624 if (CombinerAAOnlyFunc.getNumOccurrences() &&
9625 CombinerAAOnlyFunc != DAG.getMachineFunction().getName())
9628 if (UseAA && LD->isUnindexed()) {
9629 // Walk up chain skipping non-aliasing memory nodes.
9630 SDValue BetterChain = FindBetterChain(N, Chain);
9632 // If there is a better chain.
9633 if (Chain != BetterChain) {
9636 // Replace the chain to void dependency.
9637 if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
9638 ReplLoad = DAG.getLoad(N->getValueType(0), SDLoc(LD),
9639 BetterChain, Ptr, LD->getMemOperand());
9641 ReplLoad = DAG.getExtLoad(LD->getExtensionType(), SDLoc(LD),
9642 LD->getValueType(0),
9643 BetterChain, Ptr, LD->getMemoryVT(),
9644 LD->getMemOperand());
9647 // Create token factor to keep old chain connected.
9648 SDValue Token = DAG.getNode(ISD::TokenFactor, SDLoc(N),
9649 MVT::Other, Chain, ReplLoad.getValue(1));
9651 // Make sure the new and old chains are cleaned up.
9652 AddToWorklist(Token.getNode());
9654 // Replace uses with load result and token factor. Don't add users
9656 return CombineTo(N, ReplLoad.getValue(0), Token, false);
9660 // Try transforming N to an indexed load.
9661 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
9662 return SDValue(N, 0);
9664 // Try to slice up N to more direct loads if the slices are mapped to
9665 // different register banks or pairing can take place.
9667 return SDValue(N, 0);
9673 /// \brief Helper structure used to slice a load in smaller loads.
9674 /// Basically a slice is obtained from the following sequence:
9675 /// Origin = load Ty1, Base
9676 /// Shift = srl Ty1 Origin, CstTy Amount
9677 /// Inst = trunc Shift to Ty2
9679 /// Then, it will be rewriten into:
9680 /// Slice = load SliceTy, Base + SliceOffset
9681 /// [Inst = zext Slice to Ty2], only if SliceTy <> Ty2
9683 /// SliceTy is deduced from the number of bits that are actually used to
9685 struct LoadedSlice {
9686 /// \brief Helper structure used to compute the cost of a slice.
9688 /// Are we optimizing for code size.
9693 unsigned CrossRegisterBanksCopies;
9697 Cost(bool ForCodeSize = false)
9698 : ForCodeSize(ForCodeSize), Loads(0), Truncates(0),
9699 CrossRegisterBanksCopies(0), ZExts(0), Shift(0) {}
9701 /// \brief Get the cost of one isolated slice.
9702 Cost(const LoadedSlice &LS, bool ForCodeSize = false)
9703 : ForCodeSize(ForCodeSize), Loads(1), Truncates(0),
9704 CrossRegisterBanksCopies(0), ZExts(0), Shift(0) {
9705 EVT TruncType = LS.Inst->getValueType(0);
9706 EVT LoadedType = LS.getLoadedType();
9707 if (TruncType != LoadedType &&
9708 !LS.DAG->getTargetLoweringInfo().isZExtFree(LoadedType, TruncType))
9712 /// \brief Account for slicing gain in the current cost.
9713 /// Slicing provide a few gains like removing a shift or a
9714 /// truncate. This method allows to grow the cost of the original
9715 /// load with the gain from this slice.
9716 void addSliceGain(const LoadedSlice &LS) {
9717 // Each slice saves a truncate.
9718 const TargetLowering &TLI = LS.DAG->getTargetLoweringInfo();
9719 if (!TLI.isTruncateFree(LS.Inst->getValueType(0),
9720 LS.Inst->getOperand(0).getValueType()))
9722 // If there is a shift amount, this slice gets rid of it.
9725 // If this slice can merge a cross register bank copy, account for it.
9726 if (LS.canMergeExpensiveCrossRegisterBankCopy())
9727 ++CrossRegisterBanksCopies;
9730 Cost &operator+=(const Cost &RHS) {
9732 Truncates += RHS.Truncates;
9733 CrossRegisterBanksCopies += RHS.CrossRegisterBanksCopies;
9739 bool operator==(const Cost &RHS) const {
9740 return Loads == RHS.Loads && Truncates == RHS.Truncates &&
9741 CrossRegisterBanksCopies == RHS.CrossRegisterBanksCopies &&
9742 ZExts == RHS.ZExts && Shift == RHS.Shift;
9745 bool operator!=(const Cost &RHS) const { return !(*this == RHS); }
9747 bool operator<(const Cost &RHS) const {
9748 // Assume cross register banks copies are as expensive as loads.
9749 // FIXME: Do we want some more target hooks?
9750 unsigned ExpensiveOpsLHS = Loads + CrossRegisterBanksCopies;
9751 unsigned ExpensiveOpsRHS = RHS.Loads + RHS.CrossRegisterBanksCopies;
9752 // Unless we are optimizing for code size, consider the
9753 // expensive operation first.
9754 if (!ForCodeSize && ExpensiveOpsLHS != ExpensiveOpsRHS)
9755 return ExpensiveOpsLHS < ExpensiveOpsRHS;
9756 return (Truncates + ZExts + Shift + ExpensiveOpsLHS) <
9757 (RHS.Truncates + RHS.ZExts + RHS.Shift + ExpensiveOpsRHS);
9760 bool operator>(const Cost &RHS) const { return RHS < *this; }
9762 bool operator<=(const Cost &RHS) const { return !(RHS < *this); }
9764 bool operator>=(const Cost &RHS) const { return !(*this < RHS); }
9766 // The last instruction that represent the slice. This should be a
9767 // truncate instruction.
9769 // The original load instruction.
9771 // The right shift amount in bits from the original load.
9773 // The DAG from which Origin came from.
9774 // This is used to get some contextual information about legal types, etc.
9777 LoadedSlice(SDNode *Inst = nullptr, LoadSDNode *Origin = nullptr,
9778 unsigned Shift = 0, SelectionDAG *DAG = nullptr)
9779 : Inst(Inst), Origin(Origin), Shift(Shift), DAG(DAG) {}
9781 /// \brief Get the bits used in a chunk of bits \p BitWidth large.
9782 /// \return Result is \p BitWidth and has used bits set to 1 and
9783 /// not used bits set to 0.
9784 APInt getUsedBits() const {
9785 // Reproduce the trunc(lshr) sequence:
9786 // - Start from the truncated value.
9787 // - Zero extend to the desired bit width.
9789 assert(Origin && "No original load to compare against.");
9790 unsigned BitWidth = Origin->getValueSizeInBits(0);
9791 assert(Inst && "This slice is not bound to an instruction");
9792 assert(Inst->getValueSizeInBits(0) <= BitWidth &&
9793 "Extracted slice is bigger than the whole type!");
9794 APInt UsedBits(Inst->getValueSizeInBits(0), 0);
9795 UsedBits.setAllBits();
9796 UsedBits = UsedBits.zext(BitWidth);
9801 /// \brief Get the size of the slice to be loaded in bytes.
9802 unsigned getLoadedSize() const {
9803 unsigned SliceSize = getUsedBits().countPopulation();
9804 assert(!(SliceSize & 0x7) && "Size is not a multiple of a byte.");
9805 return SliceSize / 8;
9808 /// \brief Get the type that will be loaded for this slice.
9809 /// Note: This may not be the final type for the slice.
9810 EVT getLoadedType() const {
9811 assert(DAG && "Missing context");
9812 LLVMContext &Ctxt = *DAG->getContext();
9813 return EVT::getIntegerVT(Ctxt, getLoadedSize() * 8);
9816 /// \brief Get the alignment of the load used for this slice.
9817 unsigned getAlignment() const {
9818 unsigned Alignment = Origin->getAlignment();
9819 unsigned Offset = getOffsetFromBase();
9821 Alignment = MinAlign(Alignment, Alignment + Offset);
9825 /// \brief Check if this slice can be rewritten with legal operations.
9826 bool isLegal() const {
9827 // An invalid slice is not legal.
9828 if (!Origin || !Inst || !DAG)
9831 // Offsets are for indexed load only, we do not handle that.
9832 if (Origin->getOffset().getOpcode() != ISD::UNDEF)
9835 const TargetLowering &TLI = DAG->getTargetLoweringInfo();
9837 // Check that the type is legal.
9838 EVT SliceType = getLoadedType();
9839 if (!TLI.isTypeLegal(SliceType))
9842 // Check that the load is legal for this type.
9843 if (!TLI.isOperationLegal(ISD::LOAD, SliceType))
9846 // Check that the offset can be computed.
9847 // 1. Check its type.
9848 EVT PtrType = Origin->getBasePtr().getValueType();
9849 if (PtrType == MVT::Untyped || PtrType.isExtended())
9852 // 2. Check that it fits in the immediate.
9853 if (!TLI.isLegalAddImmediate(getOffsetFromBase()))
9856 // 3. Check that the computation is legal.
9857 if (!TLI.isOperationLegal(ISD::ADD, PtrType))
9860 // Check that the zext is legal if it needs one.
9861 EVT TruncateType = Inst->getValueType(0);
9862 if (TruncateType != SliceType &&
9863 !TLI.isOperationLegal(ISD::ZERO_EXTEND, TruncateType))
9869 /// \brief Get the offset in bytes of this slice in the original chunk of
9871 /// \pre DAG != nullptr.
9872 uint64_t getOffsetFromBase() const {
9873 assert(DAG && "Missing context.");
9875 DAG->getTargetLoweringInfo().getDataLayout()->isBigEndian();
9876 assert(!(Shift & 0x7) && "Shifts not aligned on Bytes are not supported.");
9877 uint64_t Offset = Shift / 8;
9878 unsigned TySizeInBytes = Origin->getValueSizeInBits(0) / 8;
9879 assert(!(Origin->getValueSizeInBits(0) & 0x7) &&
9880 "The size of the original loaded type is not a multiple of a"
9882 // If Offset is bigger than TySizeInBytes, it means we are loading all
9883 // zeros. This should have been optimized before in the process.
9884 assert(TySizeInBytes > Offset &&
9885 "Invalid shift amount for given loaded size");
9887 Offset = TySizeInBytes - Offset - getLoadedSize();
9891 /// \brief Generate the sequence of instructions to load the slice
9892 /// represented by this object and redirect the uses of this slice to
9893 /// this new sequence of instructions.
9894 /// \pre this->Inst && this->Origin are valid Instructions and this
9895 /// object passed the legal check: LoadedSlice::isLegal returned true.
9896 /// \return The last instruction of the sequence used to load the slice.
9897 SDValue loadSlice() const {
9898 assert(Inst && Origin && "Unable to replace a non-existing slice.");
9899 const SDValue &OldBaseAddr = Origin->getBasePtr();
9900 SDValue BaseAddr = OldBaseAddr;
9901 // Get the offset in that chunk of bytes w.r.t. the endianess.
9902 int64_t Offset = static_cast<int64_t>(getOffsetFromBase());
9903 assert(Offset >= 0 && "Offset too big to fit in int64_t!");
9905 // BaseAddr = BaseAddr + Offset.
9906 EVT ArithType = BaseAddr.getValueType();
9908 BaseAddr = DAG->getNode(ISD::ADD, DL, ArithType, BaseAddr,
9909 DAG->getConstant(Offset, DL, ArithType));
9912 // Create the type of the loaded slice according to its size.
9913 EVT SliceType = getLoadedType();
9915 // Create the load for the slice.
9916 SDValue LastInst = DAG->getLoad(
9917 SliceType, SDLoc(Origin), Origin->getChain(), BaseAddr,
9918 Origin->getPointerInfo().getWithOffset(Offset), Origin->isVolatile(),
9919 Origin->isNonTemporal(), Origin->isInvariant(), getAlignment());
9920 // If the final type is not the same as the loaded type, this means that
9921 // we have to pad with zero. Create a zero extend for that.
9922 EVT FinalType = Inst->getValueType(0);
9923 if (SliceType != FinalType)
9925 DAG->getNode(ISD::ZERO_EXTEND, SDLoc(LastInst), FinalType, LastInst);
9929 /// \brief Check if this slice can be merged with an expensive cross register
9930 /// bank copy. E.g.,
9932 /// f = bitcast i32 i to float
9933 bool canMergeExpensiveCrossRegisterBankCopy() const {
9934 if (!Inst || !Inst->hasOneUse())
9936 SDNode *Use = *Inst->use_begin();
9937 if (Use->getOpcode() != ISD::BITCAST)
9939 assert(DAG && "Missing context");
9940 const TargetLowering &TLI = DAG->getTargetLoweringInfo();
9941 EVT ResVT = Use->getValueType(0);
9942 const TargetRegisterClass *ResRC = TLI.getRegClassFor(ResVT.getSimpleVT());
9943 const TargetRegisterClass *ArgRC =
9944 TLI.getRegClassFor(Use->getOperand(0).getValueType().getSimpleVT());
9945 if (ArgRC == ResRC || !TLI.isOperationLegal(ISD::LOAD, ResVT))
9948 // At this point, we know that we perform a cross-register-bank copy.
9949 // Check if it is expensive.
9950 const TargetRegisterInfo *TRI = DAG->getSubtarget().getRegisterInfo();
9951 // Assume bitcasts are cheap, unless both register classes do not
9952 // explicitly share a common sub class.
9953 if (!TRI || TRI->getCommonSubClass(ArgRC, ResRC))
9956 // Check if it will be merged with the load.
9957 // 1. Check the alignment constraint.
9958 unsigned RequiredAlignment = TLI.getDataLayout()->getABITypeAlignment(
9959 ResVT.getTypeForEVT(*DAG->getContext()));
9961 if (RequiredAlignment > getAlignment())
9964 // 2. Check that the load is a legal operation for that type.
9965 if (!TLI.isOperationLegal(ISD::LOAD, ResVT))
9968 // 3. Check that we do not have a zext in the way.
9969 if (Inst->getValueType(0) != getLoadedType())
9977 /// \brief Check that all bits set in \p UsedBits form a dense region, i.e.,
9978 /// \p UsedBits looks like 0..0 1..1 0..0.
9979 static bool areUsedBitsDense(const APInt &UsedBits) {
9980 // If all the bits are one, this is dense!
9981 if (UsedBits.isAllOnesValue())
9984 // Get rid of the unused bits on the right.
9985 APInt NarrowedUsedBits = UsedBits.lshr(UsedBits.countTrailingZeros());
9986 // Get rid of the unused bits on the left.
9987 if (NarrowedUsedBits.countLeadingZeros())
9988 NarrowedUsedBits = NarrowedUsedBits.trunc(NarrowedUsedBits.getActiveBits());
9989 // Check that the chunk of bits is completely used.
9990 return NarrowedUsedBits.isAllOnesValue();
9993 /// \brief Check whether or not \p First and \p Second are next to each other
9994 /// in memory. This means that there is no hole between the bits loaded
9995 /// by \p First and the bits loaded by \p Second.
9996 static bool areSlicesNextToEachOther(const LoadedSlice &First,
9997 const LoadedSlice &Second) {
9998 assert(First.Origin == Second.Origin && First.Origin &&
9999 "Unable to match different memory origins.");
10000 APInt UsedBits = First.getUsedBits();
10001 assert((UsedBits & Second.getUsedBits()) == 0 &&
10002 "Slices are not supposed to overlap.");
10003 UsedBits |= Second.getUsedBits();
10004 return areUsedBitsDense(UsedBits);
10007 /// \brief Adjust the \p GlobalLSCost according to the target
10008 /// paring capabilities and the layout of the slices.
10009 /// \pre \p GlobalLSCost should account for at least as many loads as
10010 /// there is in the slices in \p LoadedSlices.
10011 static void adjustCostForPairing(SmallVectorImpl<LoadedSlice> &LoadedSlices,
10012 LoadedSlice::Cost &GlobalLSCost) {
10013 unsigned NumberOfSlices = LoadedSlices.size();
10014 // If there is less than 2 elements, no pairing is possible.
10015 if (NumberOfSlices < 2)
10018 // Sort the slices so that elements that are likely to be next to each
10019 // other in memory are next to each other in the list.
10020 std::sort(LoadedSlices.begin(), LoadedSlices.end(),
10021 [](const LoadedSlice &LHS, const LoadedSlice &RHS) {
10022 assert(LHS.Origin == RHS.Origin && "Different bases not implemented.");
10023 return LHS.getOffsetFromBase() < RHS.getOffsetFromBase();
10025 const TargetLowering &TLI = LoadedSlices[0].DAG->getTargetLoweringInfo();
10026 // First (resp. Second) is the first (resp. Second) potentially candidate
10027 // to be placed in a paired load.
10028 const LoadedSlice *First = nullptr;
10029 const LoadedSlice *Second = nullptr;
10030 for (unsigned CurrSlice = 0; CurrSlice < NumberOfSlices; ++CurrSlice,
10031 // Set the beginning of the pair.
10034 Second = &LoadedSlices[CurrSlice];
10036 // If First is NULL, it means we start a new pair.
10037 // Get to the next slice.
10041 EVT LoadedType = First->getLoadedType();
10043 // If the types of the slices are different, we cannot pair them.
10044 if (LoadedType != Second->getLoadedType())
10047 // Check if the target supplies paired loads for this type.
10048 unsigned RequiredAlignment = 0;
10049 if (!TLI.hasPairedLoad(LoadedType, RequiredAlignment)) {
10050 // move to the next pair, this type is hopeless.
10054 // Check if we meet the alignment requirement.
10055 if (RequiredAlignment > First->getAlignment())
10058 // Check that both loads are next to each other in memory.
10059 if (!areSlicesNextToEachOther(*First, *Second))
10062 assert(GlobalLSCost.Loads > 0 && "We save more loads than we created!");
10063 --GlobalLSCost.Loads;
10064 // Move to the next pair.
10069 /// \brief Check the profitability of all involved LoadedSlice.
10070 /// Currently, it is considered profitable if there is exactly two
10071 /// involved slices (1) which are (2) next to each other in memory, and
10072 /// whose cost (\see LoadedSlice::Cost) is smaller than the original load (3).
10074 /// Note: The order of the elements in \p LoadedSlices may be modified, but not
10075 /// the elements themselves.
10077 /// FIXME: When the cost model will be mature enough, we can relax
10078 /// constraints (1) and (2).
10079 static bool isSlicingProfitable(SmallVectorImpl<LoadedSlice> &LoadedSlices,
10080 const APInt &UsedBits, bool ForCodeSize) {
10081 unsigned NumberOfSlices = LoadedSlices.size();
10082 if (StressLoadSlicing)
10083 return NumberOfSlices > 1;
10086 if (NumberOfSlices != 2)
10090 if (!areUsedBitsDense(UsedBits))
10094 LoadedSlice::Cost OrigCost(ForCodeSize), GlobalSlicingCost(ForCodeSize);
10095 // The original code has one big load.
10096 OrigCost.Loads = 1;
10097 for (unsigned CurrSlice = 0; CurrSlice < NumberOfSlices; ++CurrSlice) {
10098 const LoadedSlice &LS = LoadedSlices[CurrSlice];
10099 // Accumulate the cost of all the slices.
10100 LoadedSlice::Cost SliceCost(LS, ForCodeSize);
10101 GlobalSlicingCost += SliceCost;
10103 // Account as cost in the original configuration the gain obtained
10104 // with the current slices.
10105 OrigCost.addSliceGain(LS);
10108 // If the target supports paired load, adjust the cost accordingly.
10109 adjustCostForPairing(LoadedSlices, GlobalSlicingCost);
10110 return OrigCost > GlobalSlicingCost;
10113 /// \brief If the given load, \p LI, is used only by trunc or trunc(lshr)
10114 /// operations, split it in the various pieces being extracted.
10116 /// This sort of thing is introduced by SROA.
10117 /// This slicing takes care not to insert overlapping loads.
10118 /// \pre LI is a simple load (i.e., not an atomic or volatile load).
10119 bool DAGCombiner::SliceUpLoad(SDNode *N) {
10120 if (Level < AfterLegalizeDAG)
10123 LoadSDNode *LD = cast<LoadSDNode>(N);
10124 if (LD->isVolatile() || !ISD::isNormalLoad(LD) ||
10125 !LD->getValueType(0).isInteger())
10128 // Keep track of already used bits to detect overlapping values.
10129 // In that case, we will just abort the transformation.
10130 APInt UsedBits(LD->getValueSizeInBits(0), 0);
10132 SmallVector<LoadedSlice, 4> LoadedSlices;
10134 // Check if this load is used as several smaller chunks of bits.
10135 // Basically, look for uses in trunc or trunc(lshr) and record a new chain
10136 // of computation for each trunc.
10137 for (SDNode::use_iterator UI = LD->use_begin(), UIEnd = LD->use_end();
10138 UI != UIEnd; ++UI) {
10139 // Skip the uses of the chain.
10140 if (UI.getUse().getResNo() != 0)
10143 SDNode *User = *UI;
10144 unsigned Shift = 0;
10146 // Check if this is a trunc(lshr).
10147 if (User->getOpcode() == ISD::SRL && User->hasOneUse() &&
10148 isa<ConstantSDNode>(User->getOperand(1))) {
10149 Shift = cast<ConstantSDNode>(User->getOperand(1))->getZExtValue();
10150 User = *User->use_begin();
10153 // At this point, User is a Truncate, iff we encountered, trunc or
10155 if (User->getOpcode() != ISD::TRUNCATE)
10158 // The width of the type must be a power of 2 and greater than 8-bits.
10159 // Otherwise the load cannot be represented in LLVM IR.
10160 // Moreover, if we shifted with a non-8-bits multiple, the slice
10161 // will be across several bytes. We do not support that.
10162 unsigned Width = User->getValueSizeInBits(0);
10163 if (Width < 8 || !isPowerOf2_32(Width) || (Shift & 0x7))
10166 // Build the slice for this chain of computations.
10167 LoadedSlice LS(User, LD, Shift, &DAG);
10168 APInt CurrentUsedBits = LS.getUsedBits();
10170 // Check if this slice overlaps with another.
10171 if ((CurrentUsedBits & UsedBits) != 0)
10173 // Update the bits used globally.
10174 UsedBits |= CurrentUsedBits;
10176 // Check if the new slice would be legal.
10180 // Record the slice.
10181 LoadedSlices.push_back(LS);
10184 // Abort slicing if it does not seem to be profitable.
10185 if (!isSlicingProfitable(LoadedSlices, UsedBits, ForCodeSize))
10190 // Rewrite each chain to use an independent load.
10191 // By construction, each chain can be represented by a unique load.
10193 // Prepare the argument for the new token factor for all the slices.
10194 SmallVector<SDValue, 8> ArgChains;
10195 for (SmallVectorImpl<LoadedSlice>::const_iterator
10196 LSIt = LoadedSlices.begin(),
10197 LSItEnd = LoadedSlices.end();
10198 LSIt != LSItEnd; ++LSIt) {
10199 SDValue SliceInst = LSIt->loadSlice();
10200 CombineTo(LSIt->Inst, SliceInst, true);
10201 if (SliceInst.getNode()->getOpcode() != ISD::LOAD)
10202 SliceInst = SliceInst.getOperand(0);
10203 assert(SliceInst->getOpcode() == ISD::LOAD &&
10204 "It takes more than a zext to get to the loaded slice!!");
10205 ArgChains.push_back(SliceInst.getValue(1));
10208 SDValue Chain = DAG.getNode(ISD::TokenFactor, SDLoc(LD), MVT::Other,
10210 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain);
10214 /// Check to see if V is (and load (ptr), imm), where the load is having
10215 /// specific bytes cleared out. If so, return the byte size being masked out
10216 /// and the shift amount.
10217 static std::pair<unsigned, unsigned>
10218 CheckForMaskedLoad(SDValue V, SDValue Ptr, SDValue Chain) {
10219 std::pair<unsigned, unsigned> Result(0, 0);
10221 // Check for the structure we're looking for.
10222 if (V->getOpcode() != ISD::AND ||
10223 !isa<ConstantSDNode>(V->getOperand(1)) ||
10224 !ISD::isNormalLoad(V->getOperand(0).getNode()))
10227 // Check the chain and pointer.
10228 LoadSDNode *LD = cast<LoadSDNode>(V->getOperand(0));
10229 if (LD->getBasePtr() != Ptr) return Result; // Not from same pointer.
10231 // The store should be chained directly to the load or be an operand of a
10233 if (LD == Chain.getNode())
10235 else if (Chain->getOpcode() != ISD::TokenFactor)
10236 return Result; // Fail.
10239 for (const SDValue &ChainOp : Chain->op_values())
10240 if (ChainOp.getNode() == LD) {
10244 if (!isOk) return Result;
10247 // This only handles simple types.
10248 if (V.getValueType() != MVT::i16 &&
10249 V.getValueType() != MVT::i32 &&
10250 V.getValueType() != MVT::i64)
10253 // Check the constant mask. Invert it so that the bits being masked out are
10254 // 0 and the bits being kept are 1. Use getSExtValue so that leading bits
10255 // follow the sign bit for uniformity.
10256 uint64_t NotMask = ~cast<ConstantSDNode>(V->getOperand(1))->getSExtValue();
10257 unsigned NotMaskLZ = countLeadingZeros(NotMask);
10258 if (NotMaskLZ & 7) return Result; // Must be multiple of a byte.
10259 unsigned NotMaskTZ = countTrailingZeros(NotMask);
10260 if (NotMaskTZ & 7) return Result; // Must be multiple of a byte.
10261 if (NotMaskLZ == 64) return Result; // All zero mask.
10263 // See if we have a continuous run of bits. If so, we have 0*1+0*
10264 if (countTrailingOnes(NotMask >> NotMaskTZ) + NotMaskTZ + NotMaskLZ != 64)
10267 // Adjust NotMaskLZ down to be from the actual size of the int instead of i64.
10268 if (V.getValueType() != MVT::i64 && NotMaskLZ)
10269 NotMaskLZ -= 64-V.getValueSizeInBits();
10271 unsigned MaskedBytes = (V.getValueSizeInBits()-NotMaskLZ-NotMaskTZ)/8;
10272 switch (MaskedBytes) {
10276 default: return Result; // All one mask, or 5-byte mask.
10279 // Verify that the first bit starts at a multiple of mask so that the access
10280 // is aligned the same as the access width.
10281 if (NotMaskTZ && NotMaskTZ/8 % MaskedBytes) return Result;
10283 Result.first = MaskedBytes;
10284 Result.second = NotMaskTZ/8;
10289 /// Check to see if IVal is something that provides a value as specified by
10290 /// MaskInfo. If so, replace the specified store with a narrower store of
10291 /// truncated IVal.
10293 ShrinkLoadReplaceStoreWithStore(const std::pair<unsigned, unsigned> &MaskInfo,
10294 SDValue IVal, StoreSDNode *St,
10296 unsigned NumBytes = MaskInfo.first;
10297 unsigned ByteShift = MaskInfo.second;
10298 SelectionDAG &DAG = DC->getDAG();
10300 // Check to see if IVal is all zeros in the part being masked in by the 'or'
10301 // that uses this. If not, this is not a replacement.
10302 APInt Mask = ~APInt::getBitsSet(IVal.getValueSizeInBits(),
10303 ByteShift*8, (ByteShift+NumBytes)*8);
10304 if (!DAG.MaskedValueIsZero(IVal, Mask)) return nullptr;
10306 // Check that it is legal on the target to do this. It is legal if the new
10307 // VT we're shrinking to (i8/i16/i32) is legal or we're still before type
10309 MVT VT = MVT::getIntegerVT(NumBytes*8);
10310 if (!DC->isTypeLegal(VT))
10313 // Okay, we can do this! Replace the 'St' store with a store of IVal that is
10314 // shifted by ByteShift and truncated down to NumBytes.
10317 IVal = DAG.getNode(ISD::SRL, DL, IVal.getValueType(), IVal,
10318 DAG.getConstant(ByteShift*8, DL,
10319 DC->getShiftAmountTy(IVal.getValueType())));
10322 // Figure out the offset for the store and the alignment of the access.
10324 unsigned NewAlign = St->getAlignment();
10326 if (DAG.getTargetLoweringInfo().isLittleEndian())
10327 StOffset = ByteShift;
10329 StOffset = IVal.getValueType().getStoreSize() - ByteShift - NumBytes;
10331 SDValue Ptr = St->getBasePtr();
10334 Ptr = DAG.getNode(ISD::ADD, DL, Ptr.getValueType(),
10335 Ptr, DAG.getConstant(StOffset, DL, Ptr.getValueType()));
10336 NewAlign = MinAlign(NewAlign, StOffset);
10339 // Truncate down to the new size.
10340 IVal = DAG.getNode(ISD::TRUNCATE, SDLoc(IVal), VT, IVal);
10343 return DAG.getStore(St->getChain(), SDLoc(St), IVal, Ptr,
10344 St->getPointerInfo().getWithOffset(StOffset),
10345 false, false, NewAlign).getNode();
10349 /// Look for sequence of load / op / store where op is one of 'or', 'xor', and
10350 /// 'and' of immediates. If 'op' is only touching some of the loaded bits, try
10351 /// narrowing the load and store if it would end up being a win for performance
10353 SDValue DAGCombiner::ReduceLoadOpStoreWidth(SDNode *N) {
10354 StoreSDNode *ST = cast<StoreSDNode>(N);
10355 if (ST->isVolatile())
10358 SDValue Chain = ST->getChain();
10359 SDValue Value = ST->getValue();
10360 SDValue Ptr = ST->getBasePtr();
10361 EVT VT = Value.getValueType();
10363 if (ST->isTruncatingStore() || VT.isVector() || !Value.hasOneUse())
10366 unsigned Opc = Value.getOpcode();
10368 // If this is "store (or X, Y), P" and X is "(and (load P), cst)", where cst
10369 // is a byte mask indicating a consecutive number of bytes, check to see if
10370 // Y is known to provide just those bytes. If so, we try to replace the
10371 // load + replace + store sequence with a single (narrower) store, which makes
10373 if (Opc == ISD::OR) {
10374 std::pair<unsigned, unsigned> MaskedLoad;
10375 MaskedLoad = CheckForMaskedLoad(Value.getOperand(0), Ptr, Chain);
10376 if (MaskedLoad.first)
10377 if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
10378 Value.getOperand(1), ST,this))
10379 return SDValue(NewST, 0);
10381 // Or is commutative, so try swapping X and Y.
10382 MaskedLoad = CheckForMaskedLoad(Value.getOperand(1), Ptr, Chain);
10383 if (MaskedLoad.first)
10384 if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
10385 Value.getOperand(0), ST,this))
10386 return SDValue(NewST, 0);
10389 if ((Opc != ISD::OR && Opc != ISD::XOR && Opc != ISD::AND) ||
10390 Value.getOperand(1).getOpcode() != ISD::Constant)
10393 SDValue N0 = Value.getOperand(0);
10394 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
10395 Chain == SDValue(N0.getNode(), 1)) {
10396 LoadSDNode *LD = cast<LoadSDNode>(N0);
10397 if (LD->getBasePtr() != Ptr ||
10398 LD->getPointerInfo().getAddrSpace() !=
10399 ST->getPointerInfo().getAddrSpace())
10402 // Find the type to narrow it the load / op / store to.
10403 SDValue N1 = Value.getOperand(1);
10404 unsigned BitWidth = N1.getValueSizeInBits();
10405 APInt Imm = cast<ConstantSDNode>(N1)->getAPIntValue();
10406 if (Opc == ISD::AND)
10407 Imm ^= APInt::getAllOnesValue(BitWidth);
10408 if (Imm == 0 || Imm.isAllOnesValue())
10410 unsigned ShAmt = Imm.countTrailingZeros();
10411 unsigned MSB = BitWidth - Imm.countLeadingZeros() - 1;
10412 unsigned NewBW = NextPowerOf2(MSB - ShAmt);
10413 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
10414 // The narrowing should be profitable, the load/store operation should be
10415 // legal (or custom) and the store size should be equal to the NewVT width.
10416 while (NewBW < BitWidth &&
10417 (NewVT.getStoreSizeInBits() != NewBW ||
10418 !TLI.isOperationLegalOrCustom(Opc, NewVT) ||
10419 !TLI.isNarrowingProfitable(VT, NewVT))) {
10420 NewBW = NextPowerOf2(NewBW);
10421 NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
10423 if (NewBW >= BitWidth)
10426 // If the lsb changed does not start at the type bitwidth boundary,
10427 // start at the previous one.
10429 ShAmt = (((ShAmt + NewBW - 1) / NewBW) * NewBW) - NewBW;
10430 APInt Mask = APInt::getBitsSet(BitWidth, ShAmt,
10431 std::min(BitWidth, ShAmt + NewBW));
10432 if ((Imm & Mask) == Imm) {
10433 APInt NewImm = (Imm & Mask).lshr(ShAmt).trunc(NewBW);
10434 if (Opc == ISD::AND)
10435 NewImm ^= APInt::getAllOnesValue(NewBW);
10436 uint64_t PtrOff = ShAmt / 8;
10437 // For big endian targets, we need to adjust the offset to the pointer to
10438 // load the correct bytes.
10439 if (TLI.isBigEndian())
10440 PtrOff = (BitWidth + 7 - NewBW) / 8 - PtrOff;
10442 unsigned NewAlign = MinAlign(LD->getAlignment(), PtrOff);
10443 Type *NewVTTy = NewVT.getTypeForEVT(*DAG.getContext());
10444 if (NewAlign < TLI.getDataLayout()->getABITypeAlignment(NewVTTy))
10447 SDValue NewPtr = DAG.getNode(ISD::ADD, SDLoc(LD),
10448 Ptr.getValueType(), Ptr,
10449 DAG.getConstant(PtrOff, SDLoc(LD),
10450 Ptr.getValueType()));
10451 SDValue NewLD = DAG.getLoad(NewVT, SDLoc(N0),
10452 LD->getChain(), NewPtr,
10453 LD->getPointerInfo().getWithOffset(PtrOff),
10454 LD->isVolatile(), LD->isNonTemporal(),
10455 LD->isInvariant(), NewAlign,
10457 SDValue NewVal = DAG.getNode(Opc, SDLoc(Value), NewVT, NewLD,
10458 DAG.getConstant(NewImm, SDLoc(Value),
10460 SDValue NewST = DAG.getStore(Chain, SDLoc(N),
10462 ST->getPointerInfo().getWithOffset(PtrOff),
10463 false, false, NewAlign);
10465 AddToWorklist(NewPtr.getNode());
10466 AddToWorklist(NewLD.getNode());
10467 AddToWorklist(NewVal.getNode());
10468 WorklistRemover DeadNodes(*this);
10469 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), NewLD.getValue(1));
10478 /// For a given floating point load / store pair, if the load value isn't used
10479 /// by any other operations, then consider transforming the pair to integer
10480 /// load / store operations if the target deems the transformation profitable.
10481 SDValue DAGCombiner::TransformFPLoadStorePair(SDNode *N) {
10482 StoreSDNode *ST = cast<StoreSDNode>(N);
10483 SDValue Chain = ST->getChain();
10484 SDValue Value = ST->getValue();
10485 if (ISD::isNormalStore(ST) && ISD::isNormalLoad(Value.getNode()) &&
10486 Value.hasOneUse() &&
10487 Chain == SDValue(Value.getNode(), 1)) {
10488 LoadSDNode *LD = cast<LoadSDNode>(Value);
10489 EVT VT = LD->getMemoryVT();
10490 if (!VT.isFloatingPoint() ||
10491 VT != ST->getMemoryVT() ||
10492 LD->isNonTemporal() ||
10493 ST->isNonTemporal() ||
10494 LD->getPointerInfo().getAddrSpace() != 0 ||
10495 ST->getPointerInfo().getAddrSpace() != 0)
10498 EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits());
10499 if (!TLI.isOperationLegal(ISD::LOAD, IntVT) ||
10500 !TLI.isOperationLegal(ISD::STORE, IntVT) ||
10501 !TLI.isDesirableToTransformToIntegerOp(ISD::LOAD, VT) ||
10502 !TLI.isDesirableToTransformToIntegerOp(ISD::STORE, VT))
10505 unsigned LDAlign = LD->getAlignment();
10506 unsigned STAlign = ST->getAlignment();
10507 Type *IntVTTy = IntVT.getTypeForEVT(*DAG.getContext());
10508 unsigned ABIAlign = TLI.getDataLayout()->getABITypeAlignment(IntVTTy);
10509 if (LDAlign < ABIAlign || STAlign < ABIAlign)
10512 SDValue NewLD = DAG.getLoad(IntVT, SDLoc(Value),
10513 LD->getChain(), LD->getBasePtr(),
10514 LD->getPointerInfo(),
10515 false, false, false, LDAlign);
10517 SDValue NewST = DAG.getStore(NewLD.getValue(1), SDLoc(N),
10518 NewLD, ST->getBasePtr(),
10519 ST->getPointerInfo(),
10520 false, false, STAlign);
10522 AddToWorklist(NewLD.getNode());
10523 AddToWorklist(NewST.getNode());
10524 WorklistRemover DeadNodes(*this);
10525 DAG.ReplaceAllUsesOfValueWith(Value.getValue(1), NewLD.getValue(1));
10534 /// Helper struct to parse and store a memory address as base + index + offset.
10535 /// We ignore sign extensions when it is safe to do so.
10536 /// The following two expressions are not equivalent. To differentiate we need
10537 /// to store whether there was a sign extension involved in the index
10539 /// (load (i64 add (i64 copyfromreg %c)
10540 /// (i64 signextend (add (i8 load %index)
10544 /// (load (i64 add (i64 copyfromreg %c)
10545 /// (i64 signextend (i32 add (i32 signextend (i8 load %index))
10547 struct BaseIndexOffset {
10551 bool IsIndexSignExt;
10553 BaseIndexOffset() : Offset(0), IsIndexSignExt(false) {}
10555 BaseIndexOffset(SDValue Base, SDValue Index, int64_t Offset,
10556 bool IsIndexSignExt) :
10557 Base(Base), Index(Index), Offset(Offset), IsIndexSignExt(IsIndexSignExt) {}
10559 bool equalBaseIndex(const BaseIndexOffset &Other) {
10560 return Other.Base == Base && Other.Index == Index &&
10561 Other.IsIndexSignExt == IsIndexSignExt;
10564 /// Parses tree in Ptr for base, index, offset addresses.
10565 static BaseIndexOffset match(SDValue Ptr) {
10566 bool IsIndexSignExt = false;
10568 // We only can pattern match BASE + INDEX + OFFSET. If Ptr is not an ADD
10569 // instruction, then it could be just the BASE or everything else we don't
10570 // know how to handle. Just use Ptr as BASE and give up.
10571 if (Ptr->getOpcode() != ISD::ADD)
10572 return BaseIndexOffset(Ptr, SDValue(), 0, IsIndexSignExt);
10574 // We know that we have at least an ADD instruction. Try to pattern match
10575 // the simple case of BASE + OFFSET.
10576 if (isa<ConstantSDNode>(Ptr->getOperand(1))) {
10577 int64_t Offset = cast<ConstantSDNode>(Ptr->getOperand(1))->getSExtValue();
10578 return BaseIndexOffset(Ptr->getOperand(0), SDValue(), Offset,
10582 // Inside a loop the current BASE pointer is calculated using an ADD and a
10583 // MUL instruction. In this case Ptr is the actual BASE pointer.
10584 // (i64 add (i64 %array_ptr)
10585 // (i64 mul (i64 %induction_var)
10586 // (i64 %element_size)))
10587 if (Ptr->getOperand(1)->getOpcode() == ISD::MUL)
10588 return BaseIndexOffset(Ptr, SDValue(), 0, IsIndexSignExt);
10590 // Look at Base + Index + Offset cases.
10591 SDValue Base = Ptr->getOperand(0);
10592 SDValue IndexOffset = Ptr->getOperand(1);
10594 // Skip signextends.
10595 if (IndexOffset->getOpcode() == ISD::SIGN_EXTEND) {
10596 IndexOffset = IndexOffset->getOperand(0);
10597 IsIndexSignExt = true;
10600 // Either the case of Base + Index (no offset) or something else.
10601 if (IndexOffset->getOpcode() != ISD::ADD)
10602 return BaseIndexOffset(Base, IndexOffset, 0, IsIndexSignExt);
10604 // Now we have the case of Base + Index + offset.
10605 SDValue Index = IndexOffset->getOperand(0);
10606 SDValue Offset = IndexOffset->getOperand(1);
10608 if (!isa<ConstantSDNode>(Offset))
10609 return BaseIndexOffset(Ptr, SDValue(), 0, IsIndexSignExt);
10611 // Ignore signextends.
10612 if (Index->getOpcode() == ISD::SIGN_EXTEND) {
10613 Index = Index->getOperand(0);
10614 IsIndexSignExt = true;
10615 } else IsIndexSignExt = false;
10617 int64_t Off = cast<ConstantSDNode>(Offset)->getSExtValue();
10618 return BaseIndexOffset(Base, Index, Off, IsIndexSignExt);
10623 SDValue DAGCombiner::getMergedConstantVectorStore(SelectionDAG &DAG,
10625 ArrayRef<MemOpLink> Stores,
10627 SmallVector<SDValue, 8> BuildVector;
10629 for (unsigned I = 0, E = Ty.getVectorNumElements(); I != E; ++I)
10630 BuildVector.push_back(cast<StoreSDNode>(Stores[I].MemNode)->getValue());
10632 return DAG.getNode(ISD::BUILD_VECTOR, SL, Ty, BuildVector);
10635 bool DAGCombiner::MergeStoresOfConstantsOrVecElts(
10636 SmallVectorImpl<MemOpLink> &StoreNodes, EVT MemVT,
10637 unsigned NumElem, bool IsConstantSrc, bool UseVector) {
10638 // Make sure we have something to merge.
10642 int64_t ElementSizeBytes = MemVT.getSizeInBits() / 8;
10643 LSBaseSDNode *FirstInChain = StoreNodes[0].MemNode;
10644 unsigned LatestNodeUsed = 0;
10646 for (unsigned i=0; i < NumElem; ++i) {
10647 // Find a chain for the new wide-store operand. Notice that some
10648 // of the store nodes that we found may not be selected for inclusion
10649 // in the wide store. The chain we use needs to be the chain of the
10650 // latest store node which is *used* and replaced by the wide store.
10651 if (StoreNodes[i].SequenceNum < StoreNodes[LatestNodeUsed].SequenceNum)
10652 LatestNodeUsed = i;
10655 // The latest Node in the DAG.
10656 LSBaseSDNode *LatestOp = StoreNodes[LatestNodeUsed].MemNode;
10657 SDLoc DL(StoreNodes[0].MemNode);
10661 // Find a legal type for the vector store.
10662 EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem);
10663 assert(TLI.isTypeLegal(Ty) && "Illegal vector store");
10664 if (IsConstantSrc) {
10665 StoredVal = getMergedConstantVectorStore(DAG, DL, StoreNodes, Ty);
10667 SmallVector<SDValue, 8> Ops;
10668 for (unsigned i = 0; i < NumElem ; ++i) {
10669 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
10670 SDValue Val = St->getValue();
10671 // All of the operands of a BUILD_VECTOR must have the same type.
10672 if (Val.getValueType() != MemVT)
10674 Ops.push_back(Val);
10677 // Build the extracted vector elements back into a vector.
10678 StoredVal = DAG.getNode(ISD::BUILD_VECTOR, DL, Ty, Ops);
10681 // We should always use a vector store when merging extracted vector
10682 // elements, so this path implies a store of constants.
10683 assert(IsConstantSrc && "Merged vector elements should use vector store");
10685 unsigned SizeInBits = NumElem * ElementSizeBytes * 8;
10686 APInt StoreInt(SizeInBits, 0);
10688 // Construct a single integer constant which is made of the smaller
10689 // constant inputs.
10690 bool IsLE = TLI.isLittleEndian();
10691 for (unsigned i = 0; i < NumElem ; ++i) {
10692 unsigned Idx = IsLE ? (NumElem - 1 - i) : i;
10693 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[Idx].MemNode);
10694 SDValue Val = St->getValue();
10695 StoreInt <<= ElementSizeBytes * 8;
10696 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Val)) {
10697 StoreInt |= C->getAPIntValue().zext(SizeInBits);
10698 } else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Val)) {
10699 StoreInt |= C->getValueAPF().bitcastToAPInt().zext(SizeInBits);
10701 llvm_unreachable("Invalid constant element type");
10705 // Create the new Load and Store operations.
10706 EVT StoreTy = EVT::getIntegerVT(*DAG.getContext(), SizeInBits);
10707 StoredVal = DAG.getConstant(StoreInt, DL, StoreTy);
10710 SDValue NewStore = DAG.getStore(LatestOp->getChain(), DL, StoredVal,
10711 FirstInChain->getBasePtr(),
10712 FirstInChain->getPointerInfo(),
10714 FirstInChain->getAlignment());
10716 // Replace the last store with the new store
10717 CombineTo(LatestOp, NewStore);
10718 // Erase all other stores.
10719 for (unsigned i = 0; i < NumElem ; ++i) {
10720 if (StoreNodes[i].MemNode == LatestOp)
10722 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
10723 // ReplaceAllUsesWith will replace all uses that existed when it was
10724 // called, but graph optimizations may cause new ones to appear. For
10725 // example, the case in pr14333 looks like
10727 // St's chain -> St -> another store -> X
10729 // And the only difference from St to the other store is the chain.
10730 // When we change it's chain to be St's chain they become identical,
10731 // get CSEed and the net result is that X is now a use of St.
10732 // Since we know that St is redundant, just iterate.
10733 while (!St->use_empty())
10734 DAG.ReplaceAllUsesWith(SDValue(St, 0), St->getChain());
10735 deleteAndRecombine(St);
10741 static bool allowableAlignment(const SelectionDAG &DAG,
10742 const TargetLowering &TLI, EVT EVTTy,
10743 unsigned AS, unsigned Align) {
10744 if (TLI.allowsMisalignedMemoryAccesses(EVTTy, AS, Align))
10747 Type *Ty = EVTTy.getTypeForEVT(*DAG.getContext());
10748 unsigned ABIAlignment = TLI.getDataLayout()->getPrefTypeAlignment(Ty);
10749 return (Align >= ABIAlignment);
10752 void DAGCombiner::getStoreMergeAndAliasCandidates(
10753 StoreSDNode* St, SmallVectorImpl<MemOpLink> &StoreNodes,
10754 SmallVectorImpl<LSBaseSDNode*> &AliasLoadNodes) {
10755 // This holds the base pointer, index, and the offset in bytes from the base
10757 BaseIndexOffset BasePtr = BaseIndexOffset::match(St->getBasePtr());
10759 // We must have a base and an offset.
10760 if (!BasePtr.Base.getNode())
10763 // Do not handle stores to undef base pointers.
10764 if (BasePtr.Base.getOpcode() == ISD::UNDEF)
10767 // Walk up the chain and look for nodes with offsets from the same
10768 // base pointer. Stop when reaching an instruction with a different kind
10769 // or instruction which has a different base pointer.
10770 EVT MemVT = St->getMemoryVT();
10772 StoreSDNode *Index = St;
10774 // If the chain has more than one use, then we can't reorder the mem ops.
10775 if (Index != St && !SDValue(Index, 0)->hasOneUse())
10778 // Find the base pointer and offset for this memory node.
10779 BaseIndexOffset Ptr = BaseIndexOffset::match(Index->getBasePtr());
10781 // Check that the base pointer is the same as the original one.
10782 if (!Ptr.equalBaseIndex(BasePtr))
10785 // The memory operands must not be volatile.
10786 if (Index->isVolatile() || Index->isIndexed())
10790 if (StoreSDNode *St = dyn_cast<StoreSDNode>(Index))
10791 if (St->isTruncatingStore())
10794 // The stored memory type must be the same.
10795 if (Index->getMemoryVT() != MemVT)
10798 // We found a potential memory operand to merge.
10799 StoreNodes.push_back(MemOpLink(Index, Ptr.Offset, Seq++));
10801 // Find the next memory operand in the chain. If the next operand in the
10802 // chain is a store then move up and continue the scan with the next
10803 // memory operand. If the next operand is a load save it and use alias
10804 // information to check if it interferes with anything.
10805 SDNode *NextInChain = Index->getChain().getNode();
10807 if (StoreSDNode *STn = dyn_cast<StoreSDNode>(NextInChain)) {
10808 // We found a store node. Use it for the next iteration.
10811 } else if (LoadSDNode *Ldn = dyn_cast<LoadSDNode>(NextInChain)) {
10812 if (Ldn->isVolatile()) {
10817 // Save the load node for later. Continue the scan.
10818 AliasLoadNodes.push_back(Ldn);
10819 NextInChain = Ldn->getChain().getNode();
10829 bool DAGCombiner::MergeConsecutiveStores(StoreSDNode* St) {
10830 if (OptLevel == CodeGenOpt::None)
10833 EVT MemVT = St->getMemoryVT();
10834 int64_t ElementSizeBytes = MemVT.getSizeInBits() / 8;
10835 bool NoVectors = DAG.getMachineFunction().getFunction()->hasFnAttribute(
10836 Attribute::NoImplicitFloat);
10838 // This function cannot currently deal with non-byte-sized memory sizes.
10839 if (ElementSizeBytes * 8 != MemVT.getSizeInBits())
10842 // Don't merge vectors into wider inputs.
10843 if (MemVT.isVector() || !MemVT.isSimple())
10846 // Perform an early exit check. Do not bother looking at stored values that
10847 // are not constants, loads, or extracted vector elements.
10848 SDValue StoredVal = St->getValue();
10849 bool IsLoadSrc = isa<LoadSDNode>(StoredVal);
10850 bool IsConstantSrc = isa<ConstantSDNode>(StoredVal) ||
10851 isa<ConstantFPSDNode>(StoredVal);
10852 bool IsExtractVecEltSrc = (StoredVal.getOpcode() == ISD::EXTRACT_VECTOR_ELT);
10854 if (!IsConstantSrc && !IsLoadSrc && !IsExtractVecEltSrc)
10857 // Only look at ends of store sequences.
10858 SDValue Chain = SDValue(St, 0);
10859 if (Chain->hasOneUse() && Chain->use_begin()->getOpcode() == ISD::STORE)
10862 // Save the LoadSDNodes that we find in the chain.
10863 // We need to make sure that these nodes do not interfere with
10864 // any of the store nodes.
10865 SmallVector<LSBaseSDNode*, 8> AliasLoadNodes;
10867 // Save the StoreSDNodes that we find in the chain.
10868 SmallVector<MemOpLink, 8> StoreNodes;
10870 getStoreMergeAndAliasCandidates(St, StoreNodes, AliasLoadNodes);
10872 // Check if there is anything to merge.
10873 if (StoreNodes.size() < 2)
10876 // Sort the memory operands according to their distance from the base pointer.
10877 std::sort(StoreNodes.begin(), StoreNodes.end(),
10878 [](MemOpLink LHS, MemOpLink RHS) {
10879 return LHS.OffsetFromBase < RHS.OffsetFromBase ||
10880 (LHS.OffsetFromBase == RHS.OffsetFromBase &&
10881 LHS.SequenceNum > RHS.SequenceNum);
10884 // Scan the memory operations on the chain and find the first non-consecutive
10885 // store memory address.
10886 unsigned LastConsecutiveStore = 0;
10887 int64_t StartAddress = StoreNodes[0].OffsetFromBase;
10888 for (unsigned i = 0, e = StoreNodes.size(); i < e; ++i) {
10890 // Check that the addresses are consecutive starting from the second
10891 // element in the list of stores.
10893 int64_t CurrAddress = StoreNodes[i].OffsetFromBase;
10894 if (CurrAddress - StartAddress != (ElementSizeBytes * i))
10898 bool Alias = false;
10899 // Check if this store interferes with any of the loads that we found.
10900 for (unsigned ld = 0, lde = AliasLoadNodes.size(); ld < lde; ++ld)
10901 if (isAlias(AliasLoadNodes[ld], StoreNodes[i].MemNode)) {
10905 // We found a load that alias with this store. Stop the sequence.
10909 // Mark this node as useful.
10910 LastConsecutiveStore = i;
10913 // The node with the lowest store address.
10914 LSBaseSDNode *FirstInChain = StoreNodes[0].MemNode;
10915 unsigned FirstStoreAS = FirstInChain->getAddressSpace();
10916 unsigned FirstStoreAlign = FirstInChain->getAlignment();
10918 // Store the constants into memory as one consecutive store.
10919 if (IsConstantSrc) {
10920 unsigned LastLegalType = 0;
10921 unsigned LastLegalVectorType = 0;
10922 bool NonZero = false;
10923 for (unsigned i=0; i<LastConsecutiveStore+1; ++i) {
10924 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
10925 SDValue StoredVal = St->getValue();
10927 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(StoredVal)) {
10928 NonZero |= !C->isNullValue();
10929 } else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(StoredVal)) {
10930 NonZero |= !C->getConstantFPValue()->isNullValue();
10936 // Find a legal type for the constant store.
10937 unsigned SizeInBits = (i+1) * ElementSizeBytes * 8;
10938 EVT StoreTy = EVT::getIntegerVT(*DAG.getContext(), SizeInBits);
10939 if (TLI.isTypeLegal(StoreTy) &&
10940 allowableAlignment(DAG, TLI, StoreTy, FirstStoreAS,
10941 FirstStoreAlign)) {
10942 LastLegalType = i+1;
10943 // Or check whether a truncstore is legal.
10944 } else if (TLI.getTypeAction(*DAG.getContext(), StoreTy) ==
10945 TargetLowering::TypePromoteInteger) {
10946 EVT LegalizedStoredValueTy =
10947 TLI.getTypeToTransformTo(*DAG.getContext(), StoredVal.getValueType());
10948 if (TLI.isTruncStoreLegal(LegalizedStoredValueTy, StoreTy) &&
10949 allowableAlignment(DAG, TLI, LegalizedStoredValueTy, FirstStoreAS,
10950 FirstStoreAlign)) {
10951 LastLegalType = i + 1;
10955 // Find a legal type for the vector store.
10956 EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
10957 if (TLI.isTypeLegal(Ty) &&
10958 allowableAlignment(DAG, TLI, Ty, FirstStoreAS, FirstStoreAlign)) {
10959 LastLegalVectorType = i + 1;
10964 // We only use vectors if the constant is known to be zero or the target
10965 // allows it and the function is not marked with the noimplicitfloat
10968 LastLegalVectorType = 0;
10969 } else if (NonZero && !TLI.storeOfVectorConstantIsCheap(MemVT,
10970 LastLegalVectorType,
10972 LastLegalVectorType = 0;
10975 // Check if we found a legal integer type to store.
10976 if (LastLegalType == 0 && LastLegalVectorType == 0)
10979 bool UseVector = (LastLegalVectorType > LastLegalType) && !NoVectors;
10980 unsigned NumElem = UseVector ? LastLegalVectorType : LastLegalType;
10982 return MergeStoresOfConstantsOrVecElts(StoreNodes, MemVT, NumElem,
10986 // When extracting multiple vector elements, try to store them
10987 // in one vector store rather than a sequence of scalar stores.
10988 if (IsExtractVecEltSrc) {
10989 unsigned NumElem = 0;
10990 for (unsigned i = 0; i < LastConsecutiveStore + 1; ++i) {
10991 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
10992 SDValue StoredVal = St->getValue();
10993 // This restriction could be loosened.
10994 // Bail out if any stored values are not elements extracted from a vector.
10995 // It should be possible to handle mixed sources, but load sources need
10996 // more careful handling (see the block of code below that handles
10997 // consecutive loads).
10998 if (StoredVal.getOpcode() != ISD::EXTRACT_VECTOR_ELT)
11001 // Find a legal type for the vector store.
11002 EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
11003 if (TLI.isTypeLegal(Ty) &&
11004 allowableAlignment(DAG, TLI, Ty, FirstStoreAS, FirstStoreAlign))
11008 return MergeStoresOfConstantsOrVecElts(StoreNodes, MemVT, NumElem,
11012 // Below we handle the case of multiple consecutive stores that
11013 // come from multiple consecutive loads. We merge them into a single
11014 // wide load and a single wide store.
11016 // Look for load nodes which are used by the stored values.
11017 SmallVector<MemOpLink, 8> LoadNodes;
11019 // Find acceptable loads. Loads need to have the same chain (token factor),
11020 // must not be zext, volatile, indexed, and they must be consecutive.
11021 BaseIndexOffset LdBasePtr;
11022 for (unsigned i=0; i<LastConsecutiveStore+1; ++i) {
11023 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
11024 LoadSDNode *Ld = dyn_cast<LoadSDNode>(St->getValue());
11027 // Loads must only have one use.
11028 if (!Ld->hasNUsesOfValue(1, 0))
11031 // The memory operands must not be volatile.
11032 if (Ld->isVolatile() || Ld->isIndexed())
11035 // We do not accept ext loads.
11036 if (Ld->getExtensionType() != ISD::NON_EXTLOAD)
11039 // The stored memory type must be the same.
11040 if (Ld->getMemoryVT() != MemVT)
11043 BaseIndexOffset LdPtr = BaseIndexOffset::match(Ld->getBasePtr());
11044 // If this is not the first ptr that we check.
11045 if (LdBasePtr.Base.getNode()) {
11046 // The base ptr must be the same.
11047 if (!LdPtr.equalBaseIndex(LdBasePtr))
11050 // Check that all other base pointers are the same as this one.
11054 // We found a potential memory operand to merge.
11055 LoadNodes.push_back(MemOpLink(Ld, LdPtr.Offset, 0));
11058 if (LoadNodes.size() < 2)
11061 // If we have load/store pair instructions and we only have two values,
11063 unsigned RequiredAlignment;
11064 if (LoadNodes.size() == 2 && TLI.hasPairedLoad(MemVT, RequiredAlignment) &&
11065 St->getAlignment() >= RequiredAlignment)
11068 LoadSDNode *FirstLoad = cast<LoadSDNode>(LoadNodes[0].MemNode);
11069 unsigned FirstLoadAS = FirstLoad->getAddressSpace();
11070 unsigned FirstLoadAlign = FirstLoad->getAlignment();
11072 // Scan the memory operations on the chain and find the first non-consecutive
11073 // load memory address. These variables hold the index in the store node
11075 unsigned LastConsecutiveLoad = 0;
11076 // This variable refers to the size and not index in the array.
11077 unsigned LastLegalVectorType = 0;
11078 unsigned LastLegalIntegerType = 0;
11079 StartAddress = LoadNodes[0].OffsetFromBase;
11080 SDValue FirstChain = FirstLoad->getChain();
11081 for (unsigned i = 1; i < LoadNodes.size(); ++i) {
11082 // All loads much share the same chain.
11083 if (LoadNodes[i].MemNode->getChain() != FirstChain)
11086 int64_t CurrAddress = LoadNodes[i].OffsetFromBase;
11087 if (CurrAddress - StartAddress != (ElementSizeBytes * i))
11089 LastConsecutiveLoad = i;
11091 // Find a legal type for the vector store.
11092 EVT StoreTy = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
11093 if (TLI.isTypeLegal(StoreTy) &&
11094 allowableAlignment(DAG, TLI, StoreTy, FirstStoreAS, FirstStoreAlign) &&
11095 allowableAlignment(DAG, TLI, StoreTy, FirstLoadAS, FirstLoadAlign)) {
11096 LastLegalVectorType = i + 1;
11099 // Find a legal type for the integer store.
11100 unsigned SizeInBits = (i+1) * ElementSizeBytes * 8;
11101 StoreTy = EVT::getIntegerVT(*DAG.getContext(), SizeInBits);
11102 if (TLI.isTypeLegal(StoreTy) &&
11103 allowableAlignment(DAG, TLI, StoreTy, FirstStoreAS, FirstStoreAlign) &&
11104 allowableAlignment(DAG, TLI, StoreTy, FirstLoadAS, FirstLoadAlign))
11105 LastLegalIntegerType = i + 1;
11106 // Or check whether a truncstore and extload is legal.
11107 else if (TLI.getTypeAction(*DAG.getContext(), StoreTy) ==
11108 TargetLowering::TypePromoteInteger) {
11109 EVT LegalizedStoredValueTy =
11110 TLI.getTypeToTransformTo(*DAG.getContext(), StoreTy);
11111 if (TLI.isTruncStoreLegal(LegalizedStoredValueTy, StoreTy) &&
11112 TLI.isLoadExtLegal(ISD::ZEXTLOAD, LegalizedStoredValueTy, StoreTy) &&
11113 TLI.isLoadExtLegal(ISD::SEXTLOAD, LegalizedStoredValueTy, StoreTy) &&
11114 TLI.isLoadExtLegal(ISD::EXTLOAD, LegalizedStoredValueTy, StoreTy) &&
11115 allowableAlignment(DAG, TLI, LegalizedStoredValueTy, FirstStoreAS,
11116 FirstStoreAlign) &&
11117 allowableAlignment(DAG, TLI, LegalizedStoredValueTy, FirstLoadAS,
11119 LastLegalIntegerType = i+1;
11123 // Only use vector types if the vector type is larger than the integer type.
11124 // If they are the same, use integers.
11125 bool UseVectorTy = LastLegalVectorType > LastLegalIntegerType && !NoVectors;
11126 unsigned LastLegalType = std::max(LastLegalVectorType, LastLegalIntegerType);
11128 // We add +1 here because the LastXXX variables refer to location while
11129 // the NumElem refers to array/index size.
11130 unsigned NumElem = std::min(LastConsecutiveStore, LastConsecutiveLoad) + 1;
11131 NumElem = std::min(LastLegalType, NumElem);
11136 // The latest Node in the DAG.
11137 unsigned LatestNodeUsed = 0;
11138 for (unsigned i=1; i<NumElem; ++i) {
11139 // Find a chain for the new wide-store operand. Notice that some
11140 // of the store nodes that we found may not be selected for inclusion
11141 // in the wide store. The chain we use needs to be the chain of the
11142 // latest store node which is *used* and replaced by the wide store.
11143 if (StoreNodes[i].SequenceNum < StoreNodes[LatestNodeUsed].SequenceNum)
11144 LatestNodeUsed = i;
11147 LSBaseSDNode *LatestOp = StoreNodes[LatestNodeUsed].MemNode;
11149 // Find if it is better to use vectors or integers to load and store
11153 JointMemOpVT = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem);
11155 unsigned SizeInBits = NumElem * ElementSizeBytes * 8;
11156 JointMemOpVT = EVT::getIntegerVT(*DAG.getContext(), SizeInBits);
11159 SDLoc LoadDL(LoadNodes[0].MemNode);
11160 SDLoc StoreDL(StoreNodes[0].MemNode);
11162 SDValue NewLoad = DAG.getLoad(
11163 JointMemOpVT, LoadDL, FirstLoad->getChain(), FirstLoad->getBasePtr(),
11164 FirstLoad->getPointerInfo(), false, false, false, FirstLoadAlign);
11166 SDValue NewStore = DAG.getStore(
11167 LatestOp->getChain(), StoreDL, NewLoad, FirstInChain->getBasePtr(),
11168 FirstInChain->getPointerInfo(), false, false, FirstStoreAlign);
11170 // Replace one of the loads with the new load.
11171 LoadSDNode *Ld = cast<LoadSDNode>(LoadNodes[0].MemNode);
11172 DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1),
11173 SDValue(NewLoad.getNode(), 1));
11175 // Remove the rest of the load chains.
11176 for (unsigned i = 1; i < NumElem ; ++i) {
11177 // Replace all chain users of the old load nodes with the chain of the new
11179 LoadSDNode *Ld = cast<LoadSDNode>(LoadNodes[i].MemNode);
11180 DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1), Ld->getChain());
11183 // Replace the last store with the new store.
11184 CombineTo(LatestOp, NewStore);
11185 // Erase all other stores.
11186 for (unsigned i = 0; i < NumElem ; ++i) {
11187 // Remove all Store nodes.
11188 if (StoreNodes[i].MemNode == LatestOp)
11190 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
11191 DAG.ReplaceAllUsesOfValueWith(SDValue(St, 0), St->getChain());
11192 deleteAndRecombine(St);
11198 SDValue DAGCombiner::visitSTORE(SDNode *N) {
11199 StoreSDNode *ST = cast<StoreSDNode>(N);
11200 SDValue Chain = ST->getChain();
11201 SDValue Value = ST->getValue();
11202 SDValue Ptr = ST->getBasePtr();
11204 // If this is a store of a bit convert, store the input value if the
11205 // resultant store does not need a higher alignment than the original.
11206 if (Value.getOpcode() == ISD::BITCAST && !ST->isTruncatingStore() &&
11207 ST->isUnindexed()) {
11208 unsigned OrigAlign = ST->getAlignment();
11209 EVT SVT = Value.getOperand(0).getValueType();
11210 unsigned Align = TLI.getDataLayout()->
11211 getABITypeAlignment(SVT.getTypeForEVT(*DAG.getContext()));
11212 if (Align <= OrigAlign &&
11213 ((!LegalOperations && !ST->isVolatile()) ||
11214 TLI.isOperationLegalOrCustom(ISD::STORE, SVT)))
11215 return DAG.getStore(Chain, SDLoc(N), Value.getOperand(0),
11216 Ptr, ST->getPointerInfo(), ST->isVolatile(),
11217 ST->isNonTemporal(), OrigAlign,
11221 // Turn 'store undef, Ptr' -> nothing.
11222 if (Value.getOpcode() == ISD::UNDEF && ST->isUnindexed())
11225 // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
11226 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Value)) {
11227 // NOTE: If the original store is volatile, this transform must not increase
11228 // the number of stores. For example, on x86-32 an f64 can be stored in one
11229 // processor operation but an i64 (which is not legal) requires two. So the
11230 // transform should not be done in this case.
11231 if (Value.getOpcode() != ISD::TargetConstantFP) {
11233 switch (CFP->getSimpleValueType(0).SimpleTy) {
11234 default: llvm_unreachable("Unknown FP type");
11235 case MVT::f16: // We don't do this for these yet.
11241 if ((isTypeLegal(MVT::i32) && !LegalOperations && !ST->isVolatile()) ||
11242 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
11244 Tmp = DAG.getConstant((uint32_t)CFP->getValueAPF().
11245 bitcastToAPInt().getZExtValue(), SDLoc(CFP),
11247 return DAG.getStore(Chain, SDLoc(N), Tmp,
11248 Ptr, ST->getMemOperand());
11252 if ((TLI.isTypeLegal(MVT::i64) && !LegalOperations &&
11253 !ST->isVolatile()) ||
11254 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i64)) {
11256 Tmp = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
11257 getZExtValue(), SDLoc(CFP), MVT::i64);
11258 return DAG.getStore(Chain, SDLoc(N), Tmp,
11259 Ptr, ST->getMemOperand());
11262 if (!ST->isVolatile() &&
11263 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
11264 // Many FP stores are not made apparent until after legalize, e.g. for
11265 // argument passing. Since this is so common, custom legalize the
11266 // 64-bit integer store into two 32-bit stores.
11267 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
11268 SDValue Lo = DAG.getConstant(Val & 0xFFFFFFFF, SDLoc(CFP), MVT::i32);
11269 SDValue Hi = DAG.getConstant(Val >> 32, SDLoc(CFP), MVT::i32);
11270 if (TLI.isBigEndian()) std::swap(Lo, Hi);
11272 unsigned Alignment = ST->getAlignment();
11273 bool isVolatile = ST->isVolatile();
11274 bool isNonTemporal = ST->isNonTemporal();
11275 AAMDNodes AAInfo = ST->getAAInfo();
11279 SDValue St0 = DAG.getStore(Chain, SDLoc(ST), Lo,
11280 Ptr, ST->getPointerInfo(),
11281 isVolatile, isNonTemporal,
11282 ST->getAlignment(), AAInfo);
11283 Ptr = DAG.getNode(ISD::ADD, DL, Ptr.getValueType(), Ptr,
11284 DAG.getConstant(4, DL, Ptr.getValueType()));
11285 Alignment = MinAlign(Alignment, 4U);
11286 SDValue St1 = DAG.getStore(Chain, SDLoc(ST), Hi,
11287 Ptr, ST->getPointerInfo().getWithOffset(4),
11288 isVolatile, isNonTemporal,
11289 Alignment, AAInfo);
11290 return DAG.getNode(ISD::TokenFactor, DL, MVT::Other,
11299 // Try to infer better alignment information than the store already has.
11300 if (OptLevel != CodeGenOpt::None && ST->isUnindexed()) {
11301 if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
11302 if (Align > ST->getAlignment()) {
11304 DAG.getTruncStore(Chain, SDLoc(N), Value,
11305 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
11306 ST->isVolatile(), ST->isNonTemporal(), Align,
11308 if (NewStore.getNode() != N)
11309 return CombineTo(ST, NewStore, true);
11314 // Try transforming a pair floating point load / store ops to integer
11315 // load / store ops.
11316 SDValue NewST = TransformFPLoadStorePair(N);
11317 if (NewST.getNode())
11320 bool UseAA = CombinerAA.getNumOccurrences() > 0 ? CombinerAA
11321 : DAG.getSubtarget().useAA();
11323 if (CombinerAAOnlyFunc.getNumOccurrences() &&
11324 CombinerAAOnlyFunc != DAG.getMachineFunction().getName())
11327 if (UseAA && ST->isUnindexed()) {
11328 // Walk up chain skipping non-aliasing memory nodes.
11329 SDValue BetterChain = FindBetterChain(N, Chain);
11331 // If there is a better chain.
11332 if (Chain != BetterChain) {
11335 // Replace the chain to avoid dependency.
11336 if (ST->isTruncatingStore()) {
11337 ReplStore = DAG.getTruncStore(BetterChain, SDLoc(N), Value, Ptr,
11338 ST->getMemoryVT(), ST->getMemOperand());
11340 ReplStore = DAG.getStore(BetterChain, SDLoc(N), Value, Ptr,
11341 ST->getMemOperand());
11344 // Create token to keep both nodes around.
11345 SDValue Token = DAG.getNode(ISD::TokenFactor, SDLoc(N),
11346 MVT::Other, Chain, ReplStore);
11348 // Make sure the new and old chains are cleaned up.
11349 AddToWorklist(Token.getNode());
11351 // Don't add users to work list.
11352 return CombineTo(N, Token, false);
11356 // Try transforming N to an indexed store.
11357 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
11358 return SDValue(N, 0);
11360 // FIXME: is there such a thing as a truncating indexed store?
11361 if (ST->isTruncatingStore() && ST->isUnindexed() &&
11362 Value.getValueType().isInteger()) {
11363 // See if we can simplify the input to this truncstore with knowledge that
11364 // only the low bits are being used. For example:
11365 // "truncstore (or (shl x, 8), y), i8" -> "truncstore y, i8"
11367 GetDemandedBits(Value,
11368 APInt::getLowBitsSet(
11369 Value.getValueType().getScalarType().getSizeInBits(),
11370 ST->getMemoryVT().getScalarType().getSizeInBits()));
11371 AddToWorklist(Value.getNode());
11372 if (Shorter.getNode())
11373 return DAG.getTruncStore(Chain, SDLoc(N), Shorter,
11374 Ptr, ST->getMemoryVT(), ST->getMemOperand());
11376 // Otherwise, see if we can simplify the operation with
11377 // SimplifyDemandedBits, which only works if the value has a single use.
11378 if (SimplifyDemandedBits(Value,
11379 APInt::getLowBitsSet(
11380 Value.getValueType().getScalarType().getSizeInBits(),
11381 ST->getMemoryVT().getScalarType().getSizeInBits())))
11382 return SDValue(N, 0);
11385 // If this is a load followed by a store to the same location, then the store
11387 if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Value)) {
11388 if (Ld->getBasePtr() == Ptr && ST->getMemoryVT() == Ld->getMemoryVT() &&
11389 ST->isUnindexed() && !ST->isVolatile() &&
11390 // There can't be any side effects between the load and store, such as
11391 // a call or store.
11392 Chain.reachesChainWithoutSideEffects(SDValue(Ld, 1))) {
11393 // The store is dead, remove it.
11398 // If this is a store followed by a store with the same value to the same
11399 // location, then the store is dead/noop.
11400 if (StoreSDNode *ST1 = dyn_cast<StoreSDNode>(Chain)) {
11401 if (ST1->getBasePtr() == Ptr && ST->getMemoryVT() == ST1->getMemoryVT() &&
11402 ST1->getValue() == Value && ST->isUnindexed() && !ST->isVolatile() &&
11403 ST1->isUnindexed() && !ST1->isVolatile()) {
11404 // The store is dead, remove it.
11409 // If this is an FP_ROUND or TRUNC followed by a store, fold this into a
11410 // truncating store. We can do this even if this is already a truncstore.
11411 if ((Value.getOpcode() == ISD::FP_ROUND || Value.getOpcode() == ISD::TRUNCATE)
11412 && Value.getNode()->hasOneUse() && ST->isUnindexed() &&
11413 TLI.isTruncStoreLegal(Value.getOperand(0).getValueType(),
11414 ST->getMemoryVT())) {
11415 return DAG.getTruncStore(Chain, SDLoc(N), Value.getOperand(0),
11416 Ptr, ST->getMemoryVT(), ST->getMemOperand());
11419 // Only perform this optimization before the types are legal, because we
11420 // don't want to perform this optimization on every DAGCombine invocation.
11422 bool EverChanged = false;
11425 // There can be multiple store sequences on the same chain.
11426 // Keep trying to merge store sequences until we are unable to do so
11427 // or until we merge the last store on the chain.
11428 bool Changed = MergeConsecutiveStores(ST);
11429 EverChanged |= Changed;
11430 if (!Changed) break;
11431 } while (ST->getOpcode() != ISD::DELETED_NODE);
11434 return SDValue(N, 0);
11437 return ReduceLoadOpStoreWidth(N);
11440 SDValue DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) {
11441 SDValue InVec = N->getOperand(0);
11442 SDValue InVal = N->getOperand(1);
11443 SDValue EltNo = N->getOperand(2);
11446 // If the inserted element is an UNDEF, just use the input vector.
11447 if (InVal.getOpcode() == ISD::UNDEF)
11450 EVT VT = InVec.getValueType();
11452 // If we can't generate a legal BUILD_VECTOR, exit
11453 if (LegalOperations && !TLI.isOperationLegal(ISD::BUILD_VECTOR, VT))
11456 // Check that we know which element is being inserted
11457 if (!isa<ConstantSDNode>(EltNo))
11459 unsigned Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
11461 // Canonicalize insert_vector_elt dag nodes.
11463 // (insert_vector_elt (insert_vector_elt A, Idx0), Idx1)
11464 // -> (insert_vector_elt (insert_vector_elt A, Idx1), Idx0)
11466 // Do this only if the child insert_vector node has one use; also
11467 // do this only if indices are both constants and Idx1 < Idx0.
11468 if (InVec.getOpcode() == ISD::INSERT_VECTOR_ELT && InVec.hasOneUse()
11469 && isa<ConstantSDNode>(InVec.getOperand(2))) {
11470 unsigned OtherElt =
11471 cast<ConstantSDNode>(InVec.getOperand(2))->getZExtValue();
11472 if (Elt < OtherElt) {
11474 SDValue NewOp = DAG.getNode(ISD::INSERT_VECTOR_ELT, SDLoc(N), VT,
11475 InVec.getOperand(0), InVal, EltNo);
11476 AddToWorklist(NewOp.getNode());
11477 return DAG.getNode(ISD::INSERT_VECTOR_ELT, SDLoc(InVec.getNode()),
11478 VT, NewOp, InVec.getOperand(1), InVec.getOperand(2));
11482 // Check that the operand is a BUILD_VECTOR (or UNDEF, which can essentially
11483 // be converted to a BUILD_VECTOR). Fill in the Ops vector with the
11484 // vector elements.
11485 SmallVector<SDValue, 8> Ops;
11486 // Do not combine these two vectors if the output vector will not replace
11487 // the input vector.
11488 if (InVec.getOpcode() == ISD::BUILD_VECTOR && InVec.hasOneUse()) {
11489 Ops.append(InVec.getNode()->op_begin(),
11490 InVec.getNode()->op_end());
11491 } else if (InVec.getOpcode() == ISD::UNDEF) {
11492 unsigned NElts = VT.getVectorNumElements();
11493 Ops.append(NElts, DAG.getUNDEF(InVal.getValueType()));
11498 // Insert the element
11499 if (Elt < Ops.size()) {
11500 // All the operands of BUILD_VECTOR must have the same type;
11501 // we enforce that here.
11502 EVT OpVT = Ops[0].getValueType();
11503 if (InVal.getValueType() != OpVT)
11504 InVal = OpVT.bitsGT(InVal.getValueType()) ?
11505 DAG.getNode(ISD::ANY_EXTEND, dl, OpVT, InVal) :
11506 DAG.getNode(ISD::TRUNCATE, dl, OpVT, InVal);
11510 // Return the new vector
11511 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
11514 SDValue DAGCombiner::ReplaceExtractVectorEltOfLoadWithNarrowedLoad(
11515 SDNode *EVE, EVT InVecVT, SDValue EltNo, LoadSDNode *OriginalLoad) {
11516 EVT ResultVT = EVE->getValueType(0);
11517 EVT VecEltVT = InVecVT.getVectorElementType();
11518 unsigned Align = OriginalLoad->getAlignment();
11519 unsigned NewAlign = TLI.getDataLayout()->getABITypeAlignment(
11520 VecEltVT.getTypeForEVT(*DAG.getContext()));
11522 if (NewAlign > Align || !TLI.isOperationLegalOrCustom(ISD::LOAD, VecEltVT))
11527 SDValue NewPtr = OriginalLoad->getBasePtr();
11529 EVT PtrType = NewPtr.getValueType();
11530 MachinePointerInfo MPI;
11532 if (auto *ConstEltNo = dyn_cast<ConstantSDNode>(EltNo)) {
11533 int Elt = ConstEltNo->getZExtValue();
11534 unsigned PtrOff = VecEltVT.getSizeInBits() * Elt / 8;
11535 Offset = DAG.getConstant(PtrOff, DL, PtrType);
11536 MPI = OriginalLoad->getPointerInfo().getWithOffset(PtrOff);
11538 Offset = DAG.getZExtOrTrunc(EltNo, DL, PtrType);
11539 Offset = DAG.getNode(
11540 ISD::MUL, DL, PtrType, Offset,
11541 DAG.getConstant(VecEltVT.getStoreSize(), DL, PtrType));
11542 MPI = OriginalLoad->getPointerInfo();
11544 NewPtr = DAG.getNode(ISD::ADD, DL, PtrType, NewPtr, Offset);
11546 // The replacement we need to do here is a little tricky: we need to
11547 // replace an extractelement of a load with a load.
11548 // Use ReplaceAllUsesOfValuesWith to do the replacement.
11549 // Note that this replacement assumes that the extractvalue is the only
11550 // use of the load; that's okay because we don't want to perform this
11551 // transformation in other cases anyway.
11554 if (ResultVT.bitsGT(VecEltVT)) {
11555 // If the result type of vextract is wider than the load, then issue an
11556 // extending load instead.
11557 ISD::LoadExtType ExtType = TLI.isLoadExtLegal(ISD::ZEXTLOAD, ResultVT,
11561 Load = DAG.getExtLoad(
11562 ExtType, SDLoc(EVE), ResultVT, OriginalLoad->getChain(), NewPtr, MPI,
11563 VecEltVT, OriginalLoad->isVolatile(), OriginalLoad->isNonTemporal(),
11564 OriginalLoad->isInvariant(), Align, OriginalLoad->getAAInfo());
11565 Chain = Load.getValue(1);
11567 Load = DAG.getLoad(
11568 VecEltVT, SDLoc(EVE), OriginalLoad->getChain(), NewPtr, MPI,
11569 OriginalLoad->isVolatile(), OriginalLoad->isNonTemporal(),
11570 OriginalLoad->isInvariant(), Align, OriginalLoad->getAAInfo());
11571 Chain = Load.getValue(1);
11572 if (ResultVT.bitsLT(VecEltVT))
11573 Load = DAG.getNode(ISD::TRUNCATE, SDLoc(EVE), ResultVT, Load);
11575 Load = DAG.getNode(ISD::BITCAST, SDLoc(EVE), ResultVT, Load);
11577 WorklistRemover DeadNodes(*this);
11578 SDValue From[] = { SDValue(EVE, 0), SDValue(OriginalLoad, 1) };
11579 SDValue To[] = { Load, Chain };
11580 DAG.ReplaceAllUsesOfValuesWith(From, To, 2);
11581 // Since we're explicitly calling ReplaceAllUses, add the new node to the
11582 // worklist explicitly as well.
11583 AddToWorklist(Load.getNode());
11584 AddUsersToWorklist(Load.getNode()); // Add users too
11585 // Make sure to revisit this node to clean it up; it will usually be dead.
11586 AddToWorklist(EVE);
11588 return SDValue(EVE, 0);
11591 SDValue DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) {
11592 // (vextract (scalar_to_vector val, 0) -> val
11593 SDValue InVec = N->getOperand(0);
11594 EVT VT = InVec.getValueType();
11595 EVT NVT = N->getValueType(0);
11597 if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR) {
11598 // Check if the result type doesn't match the inserted element type. A
11599 // SCALAR_TO_VECTOR may truncate the inserted element and the
11600 // EXTRACT_VECTOR_ELT may widen the extracted vector.
11601 SDValue InOp = InVec.getOperand(0);
11602 if (InOp.getValueType() != NVT) {
11603 assert(InOp.getValueType().isInteger() && NVT.isInteger());
11604 return DAG.getSExtOrTrunc(InOp, SDLoc(InVec), NVT);
11609 SDValue EltNo = N->getOperand(1);
11610 bool ConstEltNo = isa<ConstantSDNode>(EltNo);
11612 // Transform: (EXTRACT_VECTOR_ELT( VECTOR_SHUFFLE )) -> EXTRACT_VECTOR_ELT.
11613 // We only perform this optimization before the op legalization phase because
11614 // we may introduce new vector instructions which are not backed by TD
11615 // patterns. For example on AVX, extracting elements from a wide vector
11616 // without using extract_subvector. However, if we can find an underlying
11617 // scalar value, then we can always use that.
11618 if (InVec.getOpcode() == ISD::VECTOR_SHUFFLE
11620 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
11621 int NumElem = VT.getVectorNumElements();
11622 ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(InVec);
11623 // Find the new index to extract from.
11624 int OrigElt = SVOp->getMaskElt(Elt);
11626 // Extracting an undef index is undef.
11628 return DAG.getUNDEF(NVT);
11630 // Select the right vector half to extract from.
11632 if (OrigElt < NumElem) {
11633 SVInVec = InVec->getOperand(0);
11635 SVInVec = InVec->getOperand(1);
11636 OrigElt -= NumElem;
11639 if (SVInVec.getOpcode() == ISD::BUILD_VECTOR) {
11640 SDValue InOp = SVInVec.getOperand(OrigElt);
11641 if (InOp.getValueType() != NVT) {
11642 assert(InOp.getValueType().isInteger() && NVT.isInteger());
11643 InOp = DAG.getSExtOrTrunc(InOp, SDLoc(SVInVec), NVT);
11649 // FIXME: We should handle recursing on other vector shuffles and
11650 // scalar_to_vector here as well.
11652 if (!LegalOperations) {
11653 EVT IndexTy = TLI.getVectorIdxTy();
11654 return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SDLoc(N), NVT, SVInVec,
11655 DAG.getConstant(OrigElt, SDLoc(SVOp), IndexTy));
11659 bool BCNumEltsChanged = false;
11660 EVT ExtVT = VT.getVectorElementType();
11663 // If the result of load has to be truncated, then it's not necessarily
11665 if (NVT.bitsLT(LVT) && !TLI.isTruncateFree(LVT, NVT))
11668 if (InVec.getOpcode() == ISD::BITCAST) {
11669 // Don't duplicate a load with other uses.
11670 if (!InVec.hasOneUse())
11673 EVT BCVT = InVec.getOperand(0).getValueType();
11674 if (!BCVT.isVector() || ExtVT.bitsGT(BCVT.getVectorElementType()))
11676 if (VT.getVectorNumElements() != BCVT.getVectorNumElements())
11677 BCNumEltsChanged = true;
11678 InVec = InVec.getOperand(0);
11679 ExtVT = BCVT.getVectorElementType();
11682 // (vextract (vN[if]M load $addr), i) -> ([if]M load $addr + i * size)
11683 if (!LegalOperations && !ConstEltNo && InVec.hasOneUse() &&
11684 ISD::isNormalLoad(InVec.getNode()) &&
11685 !N->getOperand(1)->hasPredecessor(InVec.getNode())) {
11686 SDValue Index = N->getOperand(1);
11687 if (LoadSDNode *OrigLoad = dyn_cast<LoadSDNode>(InVec))
11688 return ReplaceExtractVectorEltOfLoadWithNarrowedLoad(N, VT, Index,
11692 // Perform only after legalization to ensure build_vector / vector_shuffle
11693 // optimizations have already been done.
11694 if (!LegalOperations) return SDValue();
11696 // (vextract (v4f32 load $addr), c) -> (f32 load $addr+c*size)
11697 // (vextract (v4f32 s2v (f32 load $addr)), c) -> (f32 load $addr+c*size)
11698 // (vextract (v4f32 shuffle (load $addr), <1,u,u,u>), 0) -> (f32 load $addr)
11701 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
11703 LoadSDNode *LN0 = nullptr;
11704 const ShuffleVectorSDNode *SVN = nullptr;
11705 if (ISD::isNormalLoad(InVec.getNode())) {
11706 LN0 = cast<LoadSDNode>(InVec);
11707 } else if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR &&
11708 InVec.getOperand(0).getValueType() == ExtVT &&
11709 ISD::isNormalLoad(InVec.getOperand(0).getNode())) {
11710 // Don't duplicate a load with other uses.
11711 if (!InVec.hasOneUse())
11714 LN0 = cast<LoadSDNode>(InVec.getOperand(0));
11715 } else if ((SVN = dyn_cast<ShuffleVectorSDNode>(InVec))) {
11716 // (vextract (vector_shuffle (load $addr), v2, <1, u, u, u>), 1)
11718 // (load $addr+1*size)
11720 // Don't duplicate a load with other uses.
11721 if (!InVec.hasOneUse())
11724 // If the bit convert changed the number of elements, it is unsafe
11725 // to examine the mask.
11726 if (BCNumEltsChanged)
11729 // Select the input vector, guarding against out of range extract vector.
11730 unsigned NumElems = VT.getVectorNumElements();
11731 int Idx = (Elt > (int)NumElems) ? -1 : SVN->getMaskElt(Elt);
11732 InVec = (Idx < (int)NumElems) ? InVec.getOperand(0) : InVec.getOperand(1);
11734 if (InVec.getOpcode() == ISD::BITCAST) {
11735 // Don't duplicate a load with other uses.
11736 if (!InVec.hasOneUse())
11739 InVec = InVec.getOperand(0);
11741 if (ISD::isNormalLoad(InVec.getNode())) {
11742 LN0 = cast<LoadSDNode>(InVec);
11743 Elt = (Idx < (int)NumElems) ? Idx : Idx - (int)NumElems;
11744 EltNo = DAG.getConstant(Elt, SDLoc(EltNo), EltNo.getValueType());
11748 // Make sure we found a non-volatile load and the extractelement is
11750 if (!LN0 || !LN0->hasNUsesOfValue(1,0) || LN0->isVolatile())
11753 // If Idx was -1 above, Elt is going to be -1, so just return undef.
11755 return DAG.getUNDEF(LVT);
11757 return ReplaceExtractVectorEltOfLoadWithNarrowedLoad(N, VT, EltNo, LN0);
11763 // Simplify (build_vec (ext )) to (bitcast (build_vec ))
11764 SDValue DAGCombiner::reduceBuildVecExtToExtBuildVec(SDNode *N) {
11765 // We perform this optimization post type-legalization because
11766 // the type-legalizer often scalarizes integer-promoted vectors.
11767 // Performing this optimization before may create bit-casts which
11768 // will be type-legalized to complex code sequences.
11769 // We perform this optimization only before the operation legalizer because we
11770 // may introduce illegal operations.
11771 if (Level != AfterLegalizeVectorOps && Level != AfterLegalizeTypes)
11774 unsigned NumInScalars = N->getNumOperands();
11776 EVT VT = N->getValueType(0);
11778 // Check to see if this is a BUILD_VECTOR of a bunch of values
11779 // which come from any_extend or zero_extend nodes. If so, we can create
11780 // a new BUILD_VECTOR using bit-casts which may enable other BUILD_VECTOR
11781 // optimizations. We do not handle sign-extend because we can't fill the sign
11783 EVT SourceType = MVT::Other;
11784 bool AllAnyExt = true;
11786 for (unsigned i = 0; i != NumInScalars; ++i) {
11787 SDValue In = N->getOperand(i);
11788 // Ignore undef inputs.
11789 if (In.getOpcode() == ISD::UNDEF) continue;
11791 bool AnyExt = In.getOpcode() == ISD::ANY_EXTEND;
11792 bool ZeroExt = In.getOpcode() == ISD::ZERO_EXTEND;
11794 // Abort if the element is not an extension.
11795 if (!ZeroExt && !AnyExt) {
11796 SourceType = MVT::Other;
11800 // The input is a ZeroExt or AnyExt. Check the original type.
11801 EVT InTy = In.getOperand(0).getValueType();
11803 // Check that all of the widened source types are the same.
11804 if (SourceType == MVT::Other)
11807 else if (InTy != SourceType) {
11808 // Multiple income types. Abort.
11809 SourceType = MVT::Other;
11813 // Check if all of the extends are ANY_EXTENDs.
11814 AllAnyExt &= AnyExt;
11817 // In order to have valid types, all of the inputs must be extended from the
11818 // same source type and all of the inputs must be any or zero extend.
11819 // Scalar sizes must be a power of two.
11820 EVT OutScalarTy = VT.getScalarType();
11821 bool ValidTypes = SourceType != MVT::Other &&
11822 isPowerOf2_32(OutScalarTy.getSizeInBits()) &&
11823 isPowerOf2_32(SourceType.getSizeInBits());
11825 // Create a new simpler BUILD_VECTOR sequence which other optimizations can
11826 // turn into a single shuffle instruction.
11830 bool isLE = TLI.isLittleEndian();
11831 unsigned ElemRatio = OutScalarTy.getSizeInBits()/SourceType.getSizeInBits();
11832 assert(ElemRatio > 1 && "Invalid element size ratio");
11833 SDValue Filler = AllAnyExt ? DAG.getUNDEF(SourceType):
11834 DAG.getConstant(0, SDLoc(N), SourceType);
11836 unsigned NewBVElems = ElemRatio * VT.getVectorNumElements();
11837 SmallVector<SDValue, 8> Ops(NewBVElems, Filler);
11839 // Populate the new build_vector
11840 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
11841 SDValue Cast = N->getOperand(i);
11842 assert((Cast.getOpcode() == ISD::ANY_EXTEND ||
11843 Cast.getOpcode() == ISD::ZERO_EXTEND ||
11844 Cast.getOpcode() == ISD::UNDEF) && "Invalid cast opcode");
11846 if (Cast.getOpcode() == ISD::UNDEF)
11847 In = DAG.getUNDEF(SourceType);
11849 In = Cast->getOperand(0);
11850 unsigned Index = isLE ? (i * ElemRatio) :
11851 (i * ElemRatio + (ElemRatio - 1));
11853 assert(Index < Ops.size() && "Invalid index");
11857 // The type of the new BUILD_VECTOR node.
11858 EVT VecVT = EVT::getVectorVT(*DAG.getContext(), SourceType, NewBVElems);
11859 assert(VecVT.getSizeInBits() == VT.getSizeInBits() &&
11860 "Invalid vector size");
11861 // Check if the new vector type is legal.
11862 if (!isTypeLegal(VecVT)) return SDValue();
11864 // Make the new BUILD_VECTOR.
11865 SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, dl, VecVT, Ops);
11867 // The new BUILD_VECTOR node has the potential to be further optimized.
11868 AddToWorklist(BV.getNode());
11869 // Bitcast to the desired type.
11870 return DAG.getNode(ISD::BITCAST, dl, VT, BV);
11873 SDValue DAGCombiner::reduceBuildVecConvertToConvertBuildVec(SDNode *N) {
11874 EVT VT = N->getValueType(0);
11876 unsigned NumInScalars = N->getNumOperands();
11879 EVT SrcVT = MVT::Other;
11880 unsigned Opcode = ISD::DELETED_NODE;
11881 unsigned NumDefs = 0;
11883 for (unsigned i = 0; i != NumInScalars; ++i) {
11884 SDValue In = N->getOperand(i);
11885 unsigned Opc = In.getOpcode();
11887 if (Opc == ISD::UNDEF)
11890 // If all scalar values are floats and converted from integers.
11891 if (Opcode == ISD::DELETED_NODE &&
11892 (Opc == ISD::UINT_TO_FP || Opc == ISD::SINT_TO_FP)) {
11899 EVT InVT = In.getOperand(0).getValueType();
11901 // If all scalar values are typed differently, bail out. It's chosen to
11902 // simplify BUILD_VECTOR of integer types.
11903 if (SrcVT == MVT::Other)
11910 // If the vector has just one element defined, it's not worth to fold it into
11911 // a vectorized one.
11915 assert((Opcode == ISD::UINT_TO_FP || Opcode == ISD::SINT_TO_FP)
11916 && "Should only handle conversion from integer to float.");
11917 assert(SrcVT != MVT::Other && "Cannot determine source type!");
11919 EVT NVT = EVT::getVectorVT(*DAG.getContext(), SrcVT, NumInScalars);
11921 if (!TLI.isOperationLegalOrCustom(Opcode, NVT))
11924 // Just because the floating-point vector type is legal does not necessarily
11925 // mean that the corresponding integer vector type is.
11926 if (!isTypeLegal(NVT))
11929 SmallVector<SDValue, 8> Opnds;
11930 for (unsigned i = 0; i != NumInScalars; ++i) {
11931 SDValue In = N->getOperand(i);
11933 if (In.getOpcode() == ISD::UNDEF)
11934 Opnds.push_back(DAG.getUNDEF(SrcVT));
11936 Opnds.push_back(In.getOperand(0));
11938 SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, Opnds);
11939 AddToWorklist(BV.getNode());
11941 return DAG.getNode(Opcode, dl, VT, BV);
11944 SDValue DAGCombiner::visitBUILD_VECTOR(SDNode *N) {
11945 unsigned NumInScalars = N->getNumOperands();
11947 EVT VT = N->getValueType(0);
11949 // A vector built entirely of undefs is undef.
11950 if (ISD::allOperandsUndef(N))
11951 return DAG.getUNDEF(VT);
11953 if (SDValue V = reduceBuildVecExtToExtBuildVec(N))
11956 if (SDValue V = reduceBuildVecConvertToConvertBuildVec(N))
11959 // Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT
11960 // operations. If so, and if the EXTRACT_VECTOR_ELT vector inputs come from
11961 // at most two distinct vectors, turn this into a shuffle node.
11963 // Only type-legal BUILD_VECTOR nodes are converted to shuffle nodes.
11964 if (!isTypeLegal(VT))
11967 // May only combine to shuffle after legalize if shuffle is legal.
11968 if (LegalOperations && !TLI.isOperationLegal(ISD::VECTOR_SHUFFLE, VT))
11971 SDValue VecIn1, VecIn2;
11972 bool UsesZeroVector = false;
11973 for (unsigned i = 0; i != NumInScalars; ++i) {
11974 SDValue Op = N->getOperand(i);
11975 // Ignore undef inputs.
11976 if (Op.getOpcode() == ISD::UNDEF) continue;
11978 // See if we can combine this build_vector into a blend with a zero vector.
11979 if (!VecIn2.getNode() && (isNullConstant(Op) || isNullFPConstant(Op))) {
11980 UsesZeroVector = true;
11984 // If this input is something other than a EXTRACT_VECTOR_ELT with a
11985 // constant index, bail out.
11986 if (Op.getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
11987 !isa<ConstantSDNode>(Op.getOperand(1))) {
11988 VecIn1 = VecIn2 = SDValue(nullptr, 0);
11992 // We allow up to two distinct input vectors.
11993 SDValue ExtractedFromVec = Op.getOperand(0);
11994 if (ExtractedFromVec == VecIn1 || ExtractedFromVec == VecIn2)
11997 if (!VecIn1.getNode()) {
11998 VecIn1 = ExtractedFromVec;
11999 } else if (!VecIn2.getNode() && !UsesZeroVector) {
12000 VecIn2 = ExtractedFromVec;
12002 // Too many inputs.
12003 VecIn1 = VecIn2 = SDValue(nullptr, 0);
12008 // If everything is good, we can make a shuffle operation.
12009 if (VecIn1.getNode()) {
12010 unsigned InNumElements = VecIn1.getValueType().getVectorNumElements();
12011 SmallVector<int, 8> Mask;
12012 for (unsigned i = 0; i != NumInScalars; ++i) {
12013 unsigned Opcode = N->getOperand(i).getOpcode();
12014 if (Opcode == ISD::UNDEF) {
12015 Mask.push_back(-1);
12019 // Operands can also be zero.
12020 if (Opcode != ISD::EXTRACT_VECTOR_ELT) {
12021 assert(UsesZeroVector &&
12022 (Opcode == ISD::Constant || Opcode == ISD::ConstantFP) &&
12023 "Unexpected node found!");
12024 Mask.push_back(NumInScalars+i);
12028 // If extracting from the first vector, just use the index directly.
12029 SDValue Extract = N->getOperand(i);
12030 SDValue ExtVal = Extract.getOperand(1);
12031 unsigned ExtIndex = cast<ConstantSDNode>(ExtVal)->getZExtValue();
12032 if (Extract.getOperand(0) == VecIn1) {
12033 Mask.push_back(ExtIndex);
12037 // Otherwise, use InIdx + InputVecSize
12038 Mask.push_back(InNumElements + ExtIndex);
12041 // Avoid introducing illegal shuffles with zero.
12042 if (UsesZeroVector && !TLI.isVectorClearMaskLegal(Mask, VT))
12045 // We can't generate a shuffle node with mismatched input and output types.
12046 // Attempt to transform a single input vector to the correct type.
12047 if ((VT != VecIn1.getValueType())) {
12048 // If the input vector type has a different base type to the output
12049 // vector type, bail out.
12050 EVT VTElemType = VT.getVectorElementType();
12051 if ((VecIn1.getValueType().getVectorElementType() != VTElemType) ||
12052 (VecIn2.getNode() &&
12053 (VecIn2.getValueType().getVectorElementType() != VTElemType)))
12056 // If the input vector is too small, widen it.
12057 // We only support widening of vectors which are half the size of the
12058 // output registers. For example XMM->YMM widening on X86 with AVX.
12059 EVT VecInT = VecIn1.getValueType();
12060 if (VecInT.getSizeInBits() * 2 == VT.getSizeInBits()) {
12061 // If we only have one small input, widen it by adding undef values.
12062 if (!VecIn2.getNode())
12063 VecIn1 = DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, VecIn1,
12064 DAG.getUNDEF(VecIn1.getValueType()));
12065 else if (VecIn1.getValueType() == VecIn2.getValueType()) {
12066 // If we have two small inputs of the same type, try to concat them.
12067 VecIn1 = DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, VecIn1, VecIn2);
12068 VecIn2 = SDValue(nullptr, 0);
12071 } else if (VecInT.getSizeInBits() == VT.getSizeInBits() * 2) {
12072 // If the input vector is too large, try to split it.
12073 // We don't support having two input vectors that are too large.
12074 // If the zero vector was used, we can not split the vector,
12075 // since we'd need 3 inputs.
12076 if (UsesZeroVector || VecIn2.getNode())
12079 if (!TLI.isExtractSubvectorCheap(VT, VT.getVectorNumElements()))
12082 // Try to replace VecIn1 with two extract_subvectors
12083 // No need to update the masks, they should still be correct.
12084 VecIn2 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT, VecIn1,
12085 DAG.getConstant(VT.getVectorNumElements(), dl, TLI.getVectorIdxTy()));
12086 VecIn1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT, VecIn1,
12087 DAG.getConstant(0, dl, TLI.getVectorIdxTy()));
12092 if (UsesZeroVector)
12093 VecIn2 = VT.isInteger() ? DAG.getConstant(0, dl, VT) :
12094 DAG.getConstantFP(0.0, dl, VT);
12096 // If VecIn2 is unused then change it to undef.
12097 VecIn2 = VecIn2.getNode() ? VecIn2 : DAG.getUNDEF(VT);
12099 // Check that we were able to transform all incoming values to the same
12101 if (VecIn2.getValueType() != VecIn1.getValueType() ||
12102 VecIn1.getValueType() != VT)
12105 // Return the new VECTOR_SHUFFLE node.
12109 return DAG.getVectorShuffle(VT, dl, Ops[0], Ops[1], &Mask[0]);
12115 static SDValue combineConcatVectorOfScalars(SDNode *N, SelectionDAG &DAG) {
12116 const TargetLowering &TLI = DAG.getTargetLoweringInfo();
12117 EVT OpVT = N->getOperand(0).getValueType();
12119 // If the operands are legal vectors, leave them alone.
12120 if (TLI.isTypeLegal(OpVT))
12124 EVT VT = N->getValueType(0);
12125 SmallVector<SDValue, 8> Ops;
12127 EVT SVT = EVT::getIntegerVT(*DAG.getContext(), OpVT.getSizeInBits());
12128 SDValue ScalarUndef = DAG.getNode(ISD::UNDEF, DL, SVT);
12130 // Keep track of what we encounter.
12131 bool AnyInteger = false;
12132 bool AnyFP = false;
12133 for (const SDValue &Op : N->ops()) {
12134 if (ISD::BITCAST == Op.getOpcode() &&
12135 !Op.getOperand(0).getValueType().isVector())
12136 Ops.push_back(Op.getOperand(0));
12137 else if (ISD::UNDEF == Op.getOpcode())
12138 Ops.push_back(ScalarUndef);
12142 // Note whether we encounter an integer or floating point scalar.
12143 // If it's neither, bail out, it could be something weird like x86mmx.
12144 EVT LastOpVT = Ops.back().getValueType();
12145 if (LastOpVT.isFloatingPoint())
12147 else if (LastOpVT.isInteger())
12153 // If any of the operands is a floating point scalar bitcast to a vector,
12154 // use floating point types throughout, and bitcast everything.
12155 // Replace UNDEFs by another scalar UNDEF node, of the final desired type.
12157 SVT = EVT::getFloatingPointVT(OpVT.getSizeInBits());
12158 ScalarUndef = DAG.getNode(ISD::UNDEF, DL, SVT);
12160 for (SDValue &Op : Ops) {
12161 if (Op.getValueType() == SVT)
12163 if (Op.getOpcode() == ISD::UNDEF)
12166 Op = DAG.getNode(ISD::BITCAST, DL, SVT, Op);
12171 EVT VecVT = EVT::getVectorVT(*DAG.getContext(), SVT,
12172 VT.getSizeInBits() / SVT.getSizeInBits());
12173 return DAG.getNode(ISD::BITCAST, DL, VT,
12174 DAG.getNode(ISD::BUILD_VECTOR, DL, VecVT, Ops));
12177 SDValue DAGCombiner::visitCONCAT_VECTORS(SDNode *N) {
12178 // TODO: Check to see if this is a CONCAT_VECTORS of a bunch of
12179 // EXTRACT_SUBVECTOR operations. If so, and if the EXTRACT_SUBVECTOR vector
12180 // inputs come from at most two distinct vectors, turn this into a shuffle
12183 // If we only have one input vector, we don't need to do any concatenation.
12184 if (N->getNumOperands() == 1)
12185 return N->getOperand(0);
12187 // Check if all of the operands are undefs.
12188 EVT VT = N->getValueType(0);
12189 if (ISD::allOperandsUndef(N))
12190 return DAG.getUNDEF(VT);
12192 // Optimize concat_vectors where all but the first of the vectors are undef.
12193 if (std::all_of(std::next(N->op_begin()), N->op_end(), [](const SDValue &Op) {
12194 return Op.getOpcode() == ISD::UNDEF;
12196 SDValue In = N->getOperand(0);
12197 assert(In.getValueType().isVector() && "Must concat vectors");
12199 // Transform: concat_vectors(scalar, undef) -> scalar_to_vector(sclr).
12200 if (In->getOpcode() == ISD::BITCAST &&
12201 !In->getOperand(0)->getValueType(0).isVector()) {
12202 SDValue Scalar = In->getOperand(0);
12204 // If the bitcast type isn't legal, it might be a trunc of a legal type;
12205 // look through the trunc so we can still do the transform:
12206 // concat_vectors(trunc(scalar), undef) -> scalar_to_vector(scalar)
12207 if (Scalar->getOpcode() == ISD::TRUNCATE &&
12208 !TLI.isTypeLegal(Scalar.getValueType()) &&
12209 TLI.isTypeLegal(Scalar->getOperand(0).getValueType()))
12210 Scalar = Scalar->getOperand(0);
12212 EVT SclTy = Scalar->getValueType(0);
12214 if (!SclTy.isFloatingPoint() && !SclTy.isInteger())
12217 EVT NVT = EVT::getVectorVT(*DAG.getContext(), SclTy,
12218 VT.getSizeInBits() / SclTy.getSizeInBits());
12219 if (!TLI.isTypeLegal(NVT) || !TLI.isTypeLegal(Scalar.getValueType()))
12222 SDLoc dl = SDLoc(N);
12223 SDValue Res = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, NVT, Scalar);
12224 return DAG.getNode(ISD::BITCAST, dl, VT, Res);
12228 // Fold any combination of BUILD_VECTOR or UNDEF nodes into one BUILD_VECTOR.
12229 // We have already tested above for an UNDEF only concatenation.
12230 // fold (concat_vectors (BUILD_VECTOR A, B, ...), (BUILD_VECTOR C, D, ...))
12231 // -> (BUILD_VECTOR A, B, ..., C, D, ...)
12232 auto IsBuildVectorOrUndef = [](const SDValue &Op) {
12233 return ISD::UNDEF == Op.getOpcode() || ISD::BUILD_VECTOR == Op.getOpcode();
12235 bool AllBuildVectorsOrUndefs =
12236 std::all_of(N->op_begin(), N->op_end(), IsBuildVectorOrUndef);
12237 if (AllBuildVectorsOrUndefs) {
12238 SmallVector<SDValue, 8> Opnds;
12239 EVT SVT = VT.getScalarType();
12242 if (!SVT.isFloatingPoint()) {
12243 // If BUILD_VECTOR are from built from integer, they may have different
12244 // operand types. Get the smallest type and truncate all operands to it.
12245 bool FoundMinVT = false;
12246 for (const SDValue &Op : N->ops())
12247 if (ISD::BUILD_VECTOR == Op.getOpcode()) {
12248 EVT OpSVT = Op.getOperand(0)->getValueType(0);
12249 MinVT = (!FoundMinVT || OpSVT.bitsLE(MinVT)) ? OpSVT : MinVT;
12252 assert(FoundMinVT && "Concat vector type mismatch");
12255 for (const SDValue &Op : N->ops()) {
12256 EVT OpVT = Op.getValueType();
12257 unsigned NumElts = OpVT.getVectorNumElements();
12259 if (ISD::UNDEF == Op.getOpcode())
12260 Opnds.append(NumElts, DAG.getUNDEF(MinVT));
12262 if (ISD::BUILD_VECTOR == Op.getOpcode()) {
12263 if (SVT.isFloatingPoint()) {
12264 assert(SVT == OpVT.getScalarType() && "Concat vector type mismatch");
12265 Opnds.append(Op->op_begin(), Op->op_begin() + NumElts);
12267 for (unsigned i = 0; i != NumElts; ++i)
12269 DAG.getNode(ISD::TRUNCATE, SDLoc(N), MinVT, Op.getOperand(i)));
12274 assert(VT.getVectorNumElements() == Opnds.size() &&
12275 "Concat vector type mismatch");
12276 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, Opnds);
12279 // Fold CONCAT_VECTORS of only bitcast scalars (or undef) to BUILD_VECTOR.
12280 if (SDValue V = combineConcatVectorOfScalars(N, DAG))
12283 // Type legalization of vectors and DAG canonicalization of SHUFFLE_VECTOR
12284 // nodes often generate nop CONCAT_VECTOR nodes.
12285 // Scan the CONCAT_VECTOR operands and look for a CONCAT operations that
12286 // place the incoming vectors at the exact same location.
12287 SDValue SingleSource = SDValue();
12288 unsigned PartNumElem = N->getOperand(0).getValueType().getVectorNumElements();
12290 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
12291 SDValue Op = N->getOperand(i);
12293 if (Op.getOpcode() == ISD::UNDEF)
12296 // Check if this is the identity extract:
12297 if (Op.getOpcode() != ISD::EXTRACT_SUBVECTOR)
12300 // Find the single incoming vector for the extract_subvector.
12301 if (SingleSource.getNode()) {
12302 if (Op.getOperand(0) != SingleSource)
12305 SingleSource = Op.getOperand(0);
12307 // Check the source type is the same as the type of the result.
12308 // If not, this concat may extend the vector, so we can not
12309 // optimize it away.
12310 if (SingleSource.getValueType() != N->getValueType(0))
12314 unsigned IdentityIndex = i * PartNumElem;
12315 ConstantSDNode *CS = dyn_cast<ConstantSDNode>(Op.getOperand(1));
12316 // The extract index must be constant.
12320 // Check that we are reading from the identity index.
12321 if (CS->getZExtValue() != IdentityIndex)
12325 if (SingleSource.getNode())
12326 return SingleSource;
12331 SDValue DAGCombiner::visitEXTRACT_SUBVECTOR(SDNode* N) {
12332 EVT NVT = N->getValueType(0);
12333 SDValue V = N->getOperand(0);
12335 if (V->getOpcode() == ISD::CONCAT_VECTORS) {
12337 // (extract_subvec (concat V1, V2, ...), i)
12340 // Only operand 0 is checked as 'concat' assumes all inputs of the same
12342 if (V->getOperand(0).getValueType() != NVT)
12344 unsigned Idx = N->getConstantOperandVal(1);
12345 unsigned NumElems = NVT.getVectorNumElements();
12346 assert((Idx % NumElems) == 0 &&
12347 "IDX in concat is not a multiple of the result vector length.");
12348 return V->getOperand(Idx / NumElems);
12352 if (V->getOpcode() == ISD::BITCAST)
12353 V = V.getOperand(0);
12355 if (V->getOpcode() == ISD::INSERT_SUBVECTOR) {
12357 // Handle only simple case where vector being inserted and vector
12358 // being extracted are of same type, and are half size of larger vectors.
12359 EVT BigVT = V->getOperand(0).getValueType();
12360 EVT SmallVT = V->getOperand(1).getValueType();
12361 if (!NVT.bitsEq(SmallVT) || NVT.getSizeInBits()*2 != BigVT.getSizeInBits())
12364 // Only handle cases where both indexes are constants with the same type.
12365 ConstantSDNode *ExtIdx = dyn_cast<ConstantSDNode>(N->getOperand(1));
12366 ConstantSDNode *InsIdx = dyn_cast<ConstantSDNode>(V->getOperand(2));
12368 if (InsIdx && ExtIdx &&
12369 InsIdx->getValueType(0).getSizeInBits() <= 64 &&
12370 ExtIdx->getValueType(0).getSizeInBits() <= 64) {
12372 // (extract_subvec (insert_subvec V1, V2, InsIdx), ExtIdx)
12374 // indices are equal or bit offsets are equal => V1
12375 // otherwise => (extract_subvec V1, ExtIdx)
12376 if (InsIdx->getZExtValue() * SmallVT.getScalarType().getSizeInBits() ==
12377 ExtIdx->getZExtValue() * NVT.getScalarType().getSizeInBits())
12378 return DAG.getNode(ISD::BITCAST, dl, NVT, V->getOperand(1));
12379 return DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, NVT,
12380 DAG.getNode(ISD::BITCAST, dl,
12381 N->getOperand(0).getValueType(),
12382 V->getOperand(0)), N->getOperand(1));
12389 static SDValue simplifyShuffleOperandRecursively(SmallBitVector &UsedElements,
12390 SDValue V, SelectionDAG &DAG) {
12392 EVT VT = V.getValueType();
12394 switch (V.getOpcode()) {
12398 case ISD::CONCAT_VECTORS: {
12399 EVT OpVT = V->getOperand(0).getValueType();
12400 int OpSize = OpVT.getVectorNumElements();
12401 SmallBitVector OpUsedElements(OpSize, false);
12402 bool FoundSimplification = false;
12403 SmallVector<SDValue, 4> NewOps;
12404 NewOps.reserve(V->getNumOperands());
12405 for (int i = 0, NumOps = V->getNumOperands(); i < NumOps; ++i) {
12406 SDValue Op = V->getOperand(i);
12407 bool OpUsed = false;
12408 for (int j = 0; j < OpSize; ++j)
12409 if (UsedElements[i * OpSize + j]) {
12410 OpUsedElements[j] = true;
12414 OpUsed ? simplifyShuffleOperandRecursively(OpUsedElements, Op, DAG)
12415 : DAG.getUNDEF(OpVT));
12416 FoundSimplification |= Op == NewOps.back();
12417 OpUsedElements.reset();
12419 if (FoundSimplification)
12420 V = DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, NewOps);
12424 case ISD::INSERT_SUBVECTOR: {
12425 SDValue BaseV = V->getOperand(0);
12426 SDValue SubV = V->getOperand(1);
12427 auto *IdxN = dyn_cast<ConstantSDNode>(V->getOperand(2));
12431 int SubSize = SubV.getValueType().getVectorNumElements();
12432 int Idx = IdxN->getZExtValue();
12433 bool SubVectorUsed = false;
12434 SmallBitVector SubUsedElements(SubSize, false);
12435 for (int i = 0; i < SubSize; ++i)
12436 if (UsedElements[i + Idx]) {
12437 SubVectorUsed = true;
12438 SubUsedElements[i] = true;
12439 UsedElements[i + Idx] = false;
12442 // Now recurse on both the base and sub vectors.
12443 SDValue SimplifiedSubV =
12445 ? simplifyShuffleOperandRecursively(SubUsedElements, SubV, DAG)
12446 : DAG.getUNDEF(SubV.getValueType());
12447 SDValue SimplifiedBaseV = simplifyShuffleOperandRecursively(UsedElements, BaseV, DAG);
12448 if (SimplifiedSubV != SubV || SimplifiedBaseV != BaseV)
12449 V = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, VT,
12450 SimplifiedBaseV, SimplifiedSubV, V->getOperand(2));
12456 static SDValue simplifyShuffleOperands(ShuffleVectorSDNode *SVN, SDValue N0,
12457 SDValue N1, SelectionDAG &DAG) {
12458 EVT VT = SVN->getValueType(0);
12459 int NumElts = VT.getVectorNumElements();
12460 SmallBitVector N0UsedElements(NumElts, false), N1UsedElements(NumElts, false);
12461 for (int M : SVN->getMask())
12462 if (M >= 0 && M < NumElts)
12463 N0UsedElements[M] = true;
12464 else if (M >= NumElts)
12465 N1UsedElements[M - NumElts] = true;
12467 SDValue S0 = simplifyShuffleOperandRecursively(N0UsedElements, N0, DAG);
12468 SDValue S1 = simplifyShuffleOperandRecursively(N1UsedElements, N1, DAG);
12469 if (S0 == N0 && S1 == N1)
12472 return DAG.getVectorShuffle(VT, SDLoc(SVN), S0, S1, SVN->getMask());
12475 // Tries to turn a shuffle of two CONCAT_VECTORS into a single concat,
12476 // or turn a shuffle of a single concat into simpler shuffle then concat.
12477 static SDValue partitionShuffleOfConcats(SDNode *N, SelectionDAG &DAG) {
12478 EVT VT = N->getValueType(0);
12479 unsigned NumElts = VT.getVectorNumElements();
12481 SDValue N0 = N->getOperand(0);
12482 SDValue N1 = N->getOperand(1);
12483 ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
12485 SmallVector<SDValue, 4> Ops;
12486 EVT ConcatVT = N0.getOperand(0).getValueType();
12487 unsigned NumElemsPerConcat = ConcatVT.getVectorNumElements();
12488 unsigned NumConcats = NumElts / NumElemsPerConcat;
12490 // Special case: shuffle(concat(A,B)) can be more efficiently represented
12491 // as concat(shuffle(A,B),UNDEF) if the shuffle doesn't set any of the high
12492 // half vector elements.
12493 if (NumElemsPerConcat * 2 == NumElts && N1.getOpcode() == ISD::UNDEF &&
12494 std::all_of(SVN->getMask().begin() + NumElemsPerConcat,
12495 SVN->getMask().end(), [](int i) { return i == -1; })) {
12496 N0 = DAG.getVectorShuffle(ConcatVT, SDLoc(N), N0.getOperand(0), N0.getOperand(1),
12497 ArrayRef<int>(SVN->getMask().begin(), NumElemsPerConcat));
12498 N1 = DAG.getUNDEF(ConcatVT);
12499 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT, N0, N1);
12502 // Look at every vector that's inserted. We're looking for exact
12503 // subvector-sized copies from a concatenated vector
12504 for (unsigned I = 0; I != NumConcats; ++I) {
12505 // Make sure we're dealing with a copy.
12506 unsigned Begin = I * NumElemsPerConcat;
12507 bool AllUndef = true, NoUndef = true;
12508 for (unsigned J = Begin; J != Begin + NumElemsPerConcat; ++J) {
12509 if (SVN->getMaskElt(J) >= 0)
12516 if (SVN->getMaskElt(Begin) % NumElemsPerConcat != 0)
12519 for (unsigned J = 1; J != NumElemsPerConcat; ++J)
12520 if (SVN->getMaskElt(Begin + J - 1) + 1 != SVN->getMaskElt(Begin + J))
12523 unsigned FirstElt = SVN->getMaskElt(Begin) / NumElemsPerConcat;
12524 if (FirstElt < N0.getNumOperands())
12525 Ops.push_back(N0.getOperand(FirstElt));
12527 Ops.push_back(N1.getOperand(FirstElt - N0.getNumOperands()));
12529 } else if (AllUndef) {
12530 Ops.push_back(DAG.getUNDEF(N0.getOperand(0).getValueType()));
12531 } else { // Mixed with general masks and undefs, can't do optimization.
12536 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT, Ops);
12539 SDValue DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
12540 EVT VT = N->getValueType(0);
12541 unsigned NumElts = VT.getVectorNumElements();
12543 SDValue N0 = N->getOperand(0);
12544 SDValue N1 = N->getOperand(1);
12546 assert(N0.getValueType() == VT && "Vector shuffle must be normalized in DAG");
12548 // Canonicalize shuffle undef, undef -> undef
12549 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
12550 return DAG.getUNDEF(VT);
12552 ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
12554 // Canonicalize shuffle v, v -> v, undef
12556 SmallVector<int, 8> NewMask;
12557 for (unsigned i = 0; i != NumElts; ++i) {
12558 int Idx = SVN->getMaskElt(i);
12559 if (Idx >= (int)NumElts) Idx -= NumElts;
12560 NewMask.push_back(Idx);
12562 return DAG.getVectorShuffle(VT, SDLoc(N), N0, DAG.getUNDEF(VT),
12566 // Canonicalize shuffle undef, v -> v, undef. Commute the shuffle mask.
12567 if (N0.getOpcode() == ISD::UNDEF) {
12568 SmallVector<int, 8> NewMask;
12569 for (unsigned i = 0; i != NumElts; ++i) {
12570 int Idx = SVN->getMaskElt(i);
12572 if (Idx >= (int)NumElts)
12575 Idx = -1; // remove reference to lhs
12577 NewMask.push_back(Idx);
12579 return DAG.getVectorShuffle(VT, SDLoc(N), N1, DAG.getUNDEF(VT),
12583 // Remove references to rhs if it is undef
12584 if (N1.getOpcode() == ISD::UNDEF) {
12585 bool Changed = false;
12586 SmallVector<int, 8> NewMask;
12587 for (unsigned i = 0; i != NumElts; ++i) {
12588 int Idx = SVN->getMaskElt(i);
12589 if (Idx >= (int)NumElts) {
12593 NewMask.push_back(Idx);
12596 return DAG.getVectorShuffle(VT, SDLoc(N), N0, N1, &NewMask[0]);
12599 // If it is a splat, check if the argument vector is another splat or a
12601 if (SVN->isSplat() && SVN->getSplatIndex() < (int)NumElts) {
12602 SDNode *V = N0.getNode();
12604 // If this is a bit convert that changes the element type of the vector but
12605 // not the number of vector elements, look through it. Be careful not to
12606 // look though conversions that change things like v4f32 to v2f64.
12607 if (V->getOpcode() == ISD::BITCAST) {
12608 SDValue ConvInput = V->getOperand(0);
12609 if (ConvInput.getValueType().isVector() &&
12610 ConvInput.getValueType().getVectorNumElements() == NumElts)
12611 V = ConvInput.getNode();
12614 if (V->getOpcode() == ISD::BUILD_VECTOR) {
12615 assert(V->getNumOperands() == NumElts &&
12616 "BUILD_VECTOR has wrong number of operands");
12618 bool AllSame = true;
12619 for (unsigned i = 0; i != NumElts; ++i) {
12620 if (V->getOperand(i).getOpcode() != ISD::UNDEF) {
12621 Base = V->getOperand(i);
12625 // Splat of <u, u, u, u>, return <u, u, u, u>
12626 if (!Base.getNode())
12628 for (unsigned i = 0; i != NumElts; ++i) {
12629 if (V->getOperand(i) != Base) {
12634 // Splat of <x, x, x, x>, return <x, x, x, x>
12638 // Canonicalize any other splat as a build_vector.
12639 const SDValue &Splatted = V->getOperand(SVN->getSplatIndex());
12640 SmallVector<SDValue, 8> Ops(NumElts, Splatted);
12641 SDValue NewBV = DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N),
12642 V->getValueType(0), Ops);
12644 // We may have jumped through bitcasts, so the type of the
12645 // BUILD_VECTOR may not match the type of the shuffle.
12646 if (V->getValueType(0) != VT)
12647 NewBV = DAG.getNode(ISD::BITCAST, SDLoc(N), VT, NewBV);
12652 // There are various patterns used to build up a vector from smaller vectors,
12653 // subvectors, or elements. Scan chains of these and replace unused insertions
12654 // or components with undef.
12655 if (SDValue S = simplifyShuffleOperands(SVN, N0, N1, DAG))
12658 if (N0.getOpcode() == ISD::CONCAT_VECTORS &&
12659 Level < AfterLegalizeVectorOps &&
12660 (N1.getOpcode() == ISD::UNDEF ||
12661 (N1.getOpcode() == ISD::CONCAT_VECTORS &&
12662 N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType()))) {
12663 SDValue V = partitionShuffleOfConcats(N, DAG);
12669 // Attempt to combine a shuffle of 2 inputs of 'scalar sources' -
12670 // BUILD_VECTOR or SCALAR_TO_VECTOR into a single BUILD_VECTOR.
12671 if (Level < AfterLegalizeVectorOps && TLI.isTypeLegal(VT)) {
12672 SmallVector<SDValue, 8> Ops;
12673 for (int M : SVN->getMask()) {
12674 SDValue Op = DAG.getUNDEF(VT.getScalarType());
12676 int Idx = M % NumElts;
12677 SDValue &S = (M < (int)NumElts ? N0 : N1);
12678 if (S.getOpcode() == ISD::BUILD_VECTOR && S.hasOneUse()) {
12679 Op = S.getOperand(Idx);
12680 } else if (S.getOpcode() == ISD::SCALAR_TO_VECTOR && S.hasOneUse()) {
12682 Op = S.getOperand(0);
12684 // Operand can't be combined - bail out.
12690 if (Ops.size() == VT.getVectorNumElements()) {
12691 // BUILD_VECTOR requires all inputs to be of the same type, find the
12692 // maximum type and extend them all.
12693 EVT SVT = VT.getScalarType();
12694 if (SVT.isInteger())
12695 for (SDValue &Op : Ops)
12696 SVT = (SVT.bitsLT(Op.getValueType()) ? Op.getValueType() : SVT);
12697 if (SVT != VT.getScalarType())
12698 for (SDValue &Op : Ops)
12699 Op = TLI.isZExtFree(Op.getValueType(), SVT)
12700 ? DAG.getZExtOrTrunc(Op, SDLoc(N), SVT)
12701 : DAG.getSExtOrTrunc(Op, SDLoc(N), SVT);
12702 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, Ops);
12706 // If this shuffle only has a single input that is a bitcasted shuffle,
12707 // attempt to merge the 2 shuffles and suitably bitcast the inputs/output
12708 // back to their original types.
12709 if (N0.getOpcode() == ISD::BITCAST && N0.hasOneUse() &&
12710 N1.getOpcode() == ISD::UNDEF && Level < AfterLegalizeVectorOps &&
12711 TLI.isTypeLegal(VT)) {
12713 // Peek through the bitcast only if there is one user.
12715 while (BC0.getOpcode() == ISD::BITCAST) {
12716 if (!BC0.hasOneUse())
12718 BC0 = BC0.getOperand(0);
12721 auto ScaleShuffleMask = [](ArrayRef<int> Mask, int Scale) {
12723 return SmallVector<int, 8>(Mask.begin(), Mask.end());
12725 SmallVector<int, 8> NewMask;
12727 for (int s = 0; s != Scale; ++s)
12728 NewMask.push_back(M < 0 ? -1 : Scale * M + s);
12732 if (BC0.getOpcode() == ISD::VECTOR_SHUFFLE && BC0.hasOneUse()) {
12733 EVT SVT = VT.getScalarType();
12734 EVT InnerVT = BC0->getValueType(0);
12735 EVT InnerSVT = InnerVT.getScalarType();
12737 // Determine which shuffle works with the smaller scalar type.
12738 EVT ScaleVT = SVT.bitsLT(InnerSVT) ? VT : InnerVT;
12739 EVT ScaleSVT = ScaleVT.getScalarType();
12741 if (TLI.isTypeLegal(ScaleVT) &&
12742 0 == (InnerSVT.getSizeInBits() % ScaleSVT.getSizeInBits()) &&
12743 0 == (SVT.getSizeInBits() % ScaleSVT.getSizeInBits())) {
12745 int InnerScale = InnerSVT.getSizeInBits() / ScaleSVT.getSizeInBits();
12746 int OuterScale = SVT.getSizeInBits() / ScaleSVT.getSizeInBits();
12748 // Scale the shuffle masks to the smaller scalar type.
12749 ShuffleVectorSDNode *InnerSVN = cast<ShuffleVectorSDNode>(BC0);
12750 SmallVector<int, 8> InnerMask =
12751 ScaleShuffleMask(InnerSVN->getMask(), InnerScale);
12752 SmallVector<int, 8> OuterMask =
12753 ScaleShuffleMask(SVN->getMask(), OuterScale);
12755 // Merge the shuffle masks.
12756 SmallVector<int, 8> NewMask;
12757 for (int M : OuterMask)
12758 NewMask.push_back(M < 0 ? -1 : InnerMask[M]);
12760 // Test for shuffle mask legality over both commutations.
12761 SDValue SV0 = BC0->getOperand(0);
12762 SDValue SV1 = BC0->getOperand(1);
12763 bool LegalMask = TLI.isShuffleMaskLegal(NewMask, ScaleVT);
12765 std::swap(SV0, SV1);
12766 ShuffleVectorSDNode::commuteMask(NewMask);
12767 LegalMask = TLI.isShuffleMaskLegal(NewMask, ScaleVT);
12771 SV0 = DAG.getNode(ISD::BITCAST, SDLoc(N), ScaleVT, SV0);
12772 SV1 = DAG.getNode(ISD::BITCAST, SDLoc(N), ScaleVT, SV1);
12773 return DAG.getNode(
12774 ISD::BITCAST, SDLoc(N), VT,
12775 DAG.getVectorShuffle(ScaleVT, SDLoc(N), SV0, SV1, NewMask));
12781 // Canonicalize shuffles according to rules:
12782 // shuffle(A, shuffle(A, B)) -> shuffle(shuffle(A,B), A)
12783 // shuffle(B, shuffle(A, B)) -> shuffle(shuffle(A,B), B)
12784 // shuffle(B, shuffle(A, Undef)) -> shuffle(shuffle(A, Undef), B)
12785 if (N1.getOpcode() == ISD::VECTOR_SHUFFLE &&
12786 N0.getOpcode() != ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
12787 TLI.isTypeLegal(VT)) {
12788 // The incoming shuffle must be of the same type as the result of the
12789 // current shuffle.
12790 assert(N1->getOperand(0).getValueType() == VT &&
12791 "Shuffle types don't match");
12793 SDValue SV0 = N1->getOperand(0);
12794 SDValue SV1 = N1->getOperand(1);
12795 bool HasSameOp0 = N0 == SV0;
12796 bool IsSV1Undef = SV1.getOpcode() == ISD::UNDEF;
12797 if (HasSameOp0 || IsSV1Undef || N0 == SV1)
12798 // Commute the operands of this shuffle so that next rule
12800 return DAG.getCommutedVectorShuffle(*SVN);
12803 // Try to fold according to rules:
12804 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, B, M2)
12805 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, C, M2)
12806 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(B, C, M2)
12807 // Don't try to fold shuffles with illegal type.
12808 // Only fold if this shuffle is the only user of the other shuffle.
12809 if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && N->isOnlyUserOf(N0.getNode()) &&
12810 Level < AfterLegalizeDAG && TLI.isTypeLegal(VT)) {
12811 ShuffleVectorSDNode *OtherSV = cast<ShuffleVectorSDNode>(N0);
12813 // The incoming shuffle must be of the same type as the result of the
12814 // current shuffle.
12815 assert(OtherSV->getOperand(0).getValueType() == VT &&
12816 "Shuffle types don't match");
12819 SmallVector<int, 4> Mask;
12820 // Compute the combined shuffle mask for a shuffle with SV0 as the first
12821 // operand, and SV1 as the second operand.
12822 for (unsigned i = 0; i != NumElts; ++i) {
12823 int Idx = SVN->getMaskElt(i);
12825 // Propagate Undef.
12826 Mask.push_back(Idx);
12830 SDValue CurrentVec;
12831 if (Idx < (int)NumElts) {
12832 // This shuffle index refers to the inner shuffle N0. Lookup the inner
12833 // shuffle mask to identify which vector is actually referenced.
12834 Idx = OtherSV->getMaskElt(Idx);
12836 // Propagate Undef.
12837 Mask.push_back(Idx);
12841 CurrentVec = (Idx < (int) NumElts) ? OtherSV->getOperand(0)
12842 : OtherSV->getOperand(1);
12844 // This shuffle index references an element within N1.
12848 // Simple case where 'CurrentVec' is UNDEF.
12849 if (CurrentVec.getOpcode() == ISD::UNDEF) {
12850 Mask.push_back(-1);
12854 // Canonicalize the shuffle index. We don't know yet if CurrentVec
12855 // will be the first or second operand of the combined shuffle.
12856 Idx = Idx % NumElts;
12857 if (!SV0.getNode() || SV0 == CurrentVec) {
12858 // Ok. CurrentVec is the left hand side.
12859 // Update the mask accordingly.
12861 Mask.push_back(Idx);
12865 // Bail out if we cannot convert the shuffle pair into a single shuffle.
12866 if (SV1.getNode() && SV1 != CurrentVec)
12869 // Ok. CurrentVec is the right hand side.
12870 // Update the mask accordingly.
12872 Mask.push_back(Idx + NumElts);
12875 // Check if all indices in Mask are Undef. In case, propagate Undef.
12876 bool isUndefMask = true;
12877 for (unsigned i = 0; i != NumElts && isUndefMask; ++i)
12878 isUndefMask &= Mask[i] < 0;
12881 return DAG.getUNDEF(VT);
12883 if (!SV0.getNode())
12884 SV0 = DAG.getUNDEF(VT);
12885 if (!SV1.getNode())
12886 SV1 = DAG.getUNDEF(VT);
12888 // Avoid introducing shuffles with illegal mask.
12889 if (!TLI.isShuffleMaskLegal(Mask, VT)) {
12890 ShuffleVectorSDNode::commuteMask(Mask);
12892 if (!TLI.isShuffleMaskLegal(Mask, VT))
12895 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(B, A, M2)
12896 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(C, A, M2)
12897 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(C, B, M2)
12898 std::swap(SV0, SV1);
12901 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, B, M2)
12902 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, C, M2)
12903 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(B, C, M2)
12904 return DAG.getVectorShuffle(VT, SDLoc(N), SV0, SV1, &Mask[0]);
12910 SDValue DAGCombiner::visitSCALAR_TO_VECTOR(SDNode *N) {
12911 SDValue InVal = N->getOperand(0);
12912 EVT VT = N->getValueType(0);
12914 // Replace a SCALAR_TO_VECTOR(EXTRACT_VECTOR_ELT(V,C0)) pattern
12915 // with a VECTOR_SHUFFLE.
12916 if (InVal.getOpcode() == ISD::EXTRACT_VECTOR_ELT) {
12917 SDValue InVec = InVal->getOperand(0);
12918 SDValue EltNo = InVal->getOperand(1);
12920 // FIXME: We could support implicit truncation if the shuffle can be
12921 // scaled to a smaller vector scalar type.
12922 ConstantSDNode *C0 = dyn_cast<ConstantSDNode>(EltNo);
12923 if (C0 && VT == InVec.getValueType() &&
12924 VT.getScalarType() == InVal.getValueType()) {
12925 SmallVector<int, 8> NewMask(VT.getVectorNumElements(), -1);
12926 int Elt = C0->getZExtValue();
12929 if (TLI.isShuffleMaskLegal(NewMask, VT))
12930 return DAG.getVectorShuffle(VT, SDLoc(N), InVec, DAG.getUNDEF(VT),
12938 SDValue DAGCombiner::visitINSERT_SUBVECTOR(SDNode *N) {
12939 SDValue N0 = N->getOperand(0);
12940 SDValue N2 = N->getOperand(2);
12942 // If the input vector is a concatenation, and the insert replaces
12943 // one of the halves, we can optimize into a single concat_vectors.
12944 if (N0.getOpcode() == ISD::CONCAT_VECTORS &&
12945 N0->getNumOperands() == 2 && N2.getOpcode() == ISD::Constant) {
12946 APInt InsIdx = cast<ConstantSDNode>(N2)->getAPIntValue();
12947 EVT VT = N->getValueType(0);
12949 // Lower half: fold (insert_subvector (concat_vectors X, Y), Z) ->
12950 // (concat_vectors Z, Y)
12952 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT,
12953 N->getOperand(1), N0.getOperand(1));
12955 // Upper half: fold (insert_subvector (concat_vectors X, Y), Z) ->
12956 // (concat_vectors X, Z)
12957 if (InsIdx == VT.getVectorNumElements()/2)
12958 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT,
12959 N0.getOperand(0), N->getOperand(1));
12965 SDValue DAGCombiner::visitFP_TO_FP16(SDNode *N) {
12966 SDValue N0 = N->getOperand(0);
12968 // fold (fp_to_fp16 (fp16_to_fp op)) -> op
12969 if (N0->getOpcode() == ISD::FP16_TO_FP)
12970 return N0->getOperand(0);
12975 /// Returns a vector_shuffle if it able to transform an AND to a vector_shuffle
12976 /// with the destination vector and a zero vector.
12977 /// e.g. AND V, <0xffffffff, 0, 0xffffffff, 0>. ==>
12978 /// vector_shuffle V, Zero, <0, 4, 2, 4>
12979 SDValue DAGCombiner::XformToShuffleWithZero(SDNode *N) {
12980 EVT VT = N->getValueType(0);
12981 SDValue LHS = N->getOperand(0);
12982 SDValue RHS = N->getOperand(1);
12985 // Make sure we're not running after operation legalization where it
12986 // may have custom lowered the vector shuffles.
12987 if (LegalOperations)
12990 if (N->getOpcode() != ISD::AND)
12993 if (RHS.getOpcode() == ISD::BITCAST)
12994 RHS = RHS.getOperand(0);
12996 if (RHS.getOpcode() == ISD::BUILD_VECTOR) {
12997 SmallVector<int, 8> Indices;
12998 unsigned NumElts = RHS.getNumOperands();
13000 for (unsigned i = 0; i != NumElts; ++i) {
13001 SDValue Elt = RHS.getOperand(i);
13002 if (isAllOnesConstant(Elt))
13003 Indices.push_back(i);
13004 else if (isNullConstant(Elt))
13005 Indices.push_back(NumElts+i);
13010 // Let's see if the target supports this vector_shuffle.
13011 EVT RVT = RHS.getValueType();
13012 if (!TLI.isVectorClearMaskLegal(Indices, RVT))
13015 // Return the new VECTOR_SHUFFLE node.
13016 EVT EltVT = RVT.getVectorElementType();
13017 SmallVector<SDValue,8> ZeroOps(RVT.getVectorNumElements(),
13018 DAG.getConstant(0, dl, EltVT));
13019 SDValue Zero = DAG.getNode(ISD::BUILD_VECTOR, dl, RVT, ZeroOps);
13020 LHS = DAG.getNode(ISD::BITCAST, dl, RVT, LHS);
13021 SDValue Shuf = DAG.getVectorShuffle(RVT, dl, LHS, Zero, &Indices[0]);
13022 return DAG.getNode(ISD::BITCAST, dl, VT, Shuf);
13028 /// Visit a binary vector operation, like ADD.
13029 SDValue DAGCombiner::SimplifyVBinOp(SDNode *N) {
13030 assert(N->getValueType(0).isVector() &&
13031 "SimplifyVBinOp only works on vectors!");
13033 SDValue LHS = N->getOperand(0);
13034 SDValue RHS = N->getOperand(1);
13036 if (SDValue Shuffle = XformToShuffleWithZero(N))
13039 // If the LHS and RHS are BUILD_VECTOR nodes, see if we can constant fold
13041 if (LHS.getOpcode() == ISD::BUILD_VECTOR &&
13042 RHS.getOpcode() == ISD::BUILD_VECTOR) {
13043 // Check if both vectors are constants. If not bail out.
13044 if (!(cast<BuildVectorSDNode>(LHS)->isConstant() &&
13045 cast<BuildVectorSDNode>(RHS)->isConstant()))
13048 SmallVector<SDValue, 8> Ops;
13049 for (unsigned i = 0, e = LHS.getNumOperands(); i != e; ++i) {
13050 SDValue LHSOp = LHS.getOperand(i);
13051 SDValue RHSOp = RHS.getOperand(i);
13053 // Can't fold divide by zero.
13054 if (N->getOpcode() == ISD::SDIV || N->getOpcode() == ISD::UDIV ||
13055 N->getOpcode() == ISD::FDIV) {
13056 if (isNullConstant(RHSOp) || (RHSOp.getOpcode() == ISD::ConstantFP &&
13057 cast<ConstantFPSDNode>(RHSOp.getNode())->isZero()))
13061 EVT VT = LHSOp.getValueType();
13062 EVT RVT = RHSOp.getValueType();
13064 // Integer BUILD_VECTOR operands may have types larger than the element
13065 // size (e.g., when the element type is not legal). Prior to type
13066 // legalization, the types may not match between the two BUILD_VECTORS.
13067 // Truncate one of the operands to make them match.
13068 if (RVT.getSizeInBits() > VT.getSizeInBits()) {
13069 RHSOp = DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, RHSOp);
13071 LHSOp = DAG.getNode(ISD::TRUNCATE, SDLoc(N), RVT, LHSOp);
13075 SDValue FoldOp = DAG.getNode(N->getOpcode(), SDLoc(LHS), VT,
13077 if (FoldOp.getOpcode() != ISD::UNDEF &&
13078 FoldOp.getOpcode() != ISD::Constant &&
13079 FoldOp.getOpcode() != ISD::ConstantFP)
13081 Ops.push_back(FoldOp);
13082 AddToWorklist(FoldOp.getNode());
13085 if (Ops.size() == LHS.getNumOperands())
13086 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), LHS.getValueType(), Ops);
13089 // Type legalization might introduce new shuffles in the DAG.
13090 // Fold (VBinOp (shuffle (A, Undef, Mask)), (shuffle (B, Undef, Mask)))
13091 // -> (shuffle (VBinOp (A, B)), Undef, Mask).
13092 if (LegalTypes && isa<ShuffleVectorSDNode>(LHS) &&
13093 isa<ShuffleVectorSDNode>(RHS) && LHS.hasOneUse() && RHS.hasOneUse() &&
13094 LHS.getOperand(1).getOpcode() == ISD::UNDEF &&
13095 RHS.getOperand(1).getOpcode() == ISD::UNDEF) {
13096 ShuffleVectorSDNode *SVN0 = cast<ShuffleVectorSDNode>(LHS);
13097 ShuffleVectorSDNode *SVN1 = cast<ShuffleVectorSDNode>(RHS);
13099 if (SVN0->getMask().equals(SVN1->getMask())) {
13100 EVT VT = N->getValueType(0);
13101 SDValue UndefVector = LHS.getOperand(1);
13102 SDValue NewBinOp = DAG.getNode(N->getOpcode(), SDLoc(N), VT,
13103 LHS.getOperand(0), RHS.getOperand(0));
13104 AddUsersToWorklist(N);
13105 return DAG.getVectorShuffle(VT, SDLoc(N), NewBinOp, UndefVector,
13106 &SVN0->getMask()[0]);
13113 SDValue DAGCombiner::SimplifySelect(SDLoc DL, SDValue N0,
13114 SDValue N1, SDValue N2){
13115 assert(N0.getOpcode() ==ISD::SETCC && "First argument must be a SetCC node!");
13117 SDValue SCC = SimplifySelectCC(DL, N0.getOperand(0), N0.getOperand(1), N1, N2,
13118 cast<CondCodeSDNode>(N0.getOperand(2))->get());
13120 // If we got a simplified select_cc node back from SimplifySelectCC, then
13121 // break it down into a new SETCC node, and a new SELECT node, and then return
13122 // the SELECT node, since we were called with a SELECT node.
13123 if (SCC.getNode()) {
13124 // Check to see if we got a select_cc back (to turn into setcc/select).
13125 // Otherwise, just return whatever node we got back, like fabs.
13126 if (SCC.getOpcode() == ISD::SELECT_CC) {
13127 SDValue SETCC = DAG.getNode(ISD::SETCC, SDLoc(N0),
13129 SCC.getOperand(0), SCC.getOperand(1),
13130 SCC.getOperand(4));
13131 AddToWorklist(SETCC.getNode());
13132 return DAG.getSelect(SDLoc(SCC), SCC.getValueType(), SETCC,
13133 SCC.getOperand(2), SCC.getOperand(3));
13141 /// Given a SELECT or a SELECT_CC node, where LHS and RHS are the two values
13142 /// being selected between, see if we can simplify the select. Callers of this
13143 /// should assume that TheSelect is deleted if this returns true. As such, they
13144 /// should return the appropriate thing (e.g. the node) back to the top-level of
13145 /// the DAG combiner loop to avoid it being looked at.
13146 bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS,
13149 // fold (select (setcc x, -0.0, *lt), NaN, (fsqrt x))
13150 // The select + setcc is redundant, because fsqrt returns NaN for X < -0.
13151 if (const ConstantFPSDNode *NaN = isConstOrConstSplatFP(LHS)) {
13152 if (NaN->isNaN() && RHS.getOpcode() == ISD::FSQRT) {
13153 // We have: (select (setcc ?, ?, ?), NaN, (fsqrt ?))
13154 SDValue Sqrt = RHS;
13157 const ConstantFPSDNode *NegZero = nullptr;
13159 if (TheSelect->getOpcode() == ISD::SELECT_CC) {
13160 CC = dyn_cast<CondCodeSDNode>(TheSelect->getOperand(4))->get();
13161 CmpLHS = TheSelect->getOperand(0);
13162 NegZero = isConstOrConstSplatFP(TheSelect->getOperand(1));
13164 // SELECT or VSELECT
13165 SDValue Cmp = TheSelect->getOperand(0);
13166 if (Cmp.getOpcode() == ISD::SETCC) {
13167 CC = dyn_cast<CondCodeSDNode>(Cmp.getOperand(2))->get();
13168 CmpLHS = Cmp.getOperand(0);
13169 NegZero = isConstOrConstSplatFP(Cmp.getOperand(1));
13172 if (NegZero && NegZero->isNegative() && NegZero->isZero() &&
13173 Sqrt.getOperand(0) == CmpLHS && (CC == ISD::SETOLT ||
13174 CC == ISD::SETULT || CC == ISD::SETLT)) {
13175 // We have: (select (setcc x, -0.0, *lt), NaN, (fsqrt x))
13176 CombineTo(TheSelect, Sqrt);
13181 // Cannot simplify select with vector condition
13182 if (TheSelect->getOperand(0).getValueType().isVector()) return false;
13184 // If this is a select from two identical things, try to pull the operation
13185 // through the select.
13186 if (LHS.getOpcode() != RHS.getOpcode() ||
13187 !LHS.hasOneUse() || !RHS.hasOneUse())
13190 // If this is a load and the token chain is identical, replace the select
13191 // of two loads with a load through a select of the address to load from.
13192 // This triggers in things like "select bool X, 10.0, 123.0" after the FP
13193 // constants have been dropped into the constant pool.
13194 if (LHS.getOpcode() == ISD::LOAD) {
13195 LoadSDNode *LLD = cast<LoadSDNode>(LHS);
13196 LoadSDNode *RLD = cast<LoadSDNode>(RHS);
13198 // Token chains must be identical.
13199 if (LHS.getOperand(0) != RHS.getOperand(0) ||
13200 // Do not let this transformation reduce the number of volatile loads.
13201 LLD->isVolatile() || RLD->isVolatile() ||
13202 // FIXME: If either is a pre/post inc/dec load,
13203 // we'd need to split out the address adjustment.
13204 LLD->isIndexed() || RLD->isIndexed() ||
13205 // If this is an EXTLOAD, the VT's must match.
13206 LLD->getMemoryVT() != RLD->getMemoryVT() ||
13207 // If this is an EXTLOAD, the kind of extension must match.
13208 (LLD->getExtensionType() != RLD->getExtensionType() &&
13209 // The only exception is if one of the extensions is anyext.
13210 LLD->getExtensionType() != ISD::EXTLOAD &&
13211 RLD->getExtensionType() != ISD::EXTLOAD) ||
13212 // FIXME: this discards src value information. This is
13213 // over-conservative. It would be beneficial to be able to remember
13214 // both potential memory locations. Since we are discarding
13215 // src value info, don't do the transformation if the memory
13216 // locations are not in the default address space.
13217 LLD->getPointerInfo().getAddrSpace() != 0 ||
13218 RLD->getPointerInfo().getAddrSpace() != 0 ||
13219 !TLI.isOperationLegalOrCustom(TheSelect->getOpcode(),
13220 LLD->getBasePtr().getValueType()))
13223 // Check that the select condition doesn't reach either load. If so,
13224 // folding this will induce a cycle into the DAG. If not, this is safe to
13225 // xform, so create a select of the addresses.
13227 if (TheSelect->getOpcode() == ISD::SELECT) {
13228 SDNode *CondNode = TheSelect->getOperand(0).getNode();
13229 if ((LLD->hasAnyUseOfValue(1) && LLD->isPredecessorOf(CondNode)) ||
13230 (RLD->hasAnyUseOfValue(1) && RLD->isPredecessorOf(CondNode)))
13232 // The loads must not depend on one another.
13233 if (LLD->isPredecessorOf(RLD) ||
13234 RLD->isPredecessorOf(LLD))
13236 Addr = DAG.getSelect(SDLoc(TheSelect),
13237 LLD->getBasePtr().getValueType(),
13238 TheSelect->getOperand(0), LLD->getBasePtr(),
13239 RLD->getBasePtr());
13240 } else { // Otherwise SELECT_CC
13241 SDNode *CondLHS = TheSelect->getOperand(0).getNode();
13242 SDNode *CondRHS = TheSelect->getOperand(1).getNode();
13244 if ((LLD->hasAnyUseOfValue(1) &&
13245 (LLD->isPredecessorOf(CondLHS) || LLD->isPredecessorOf(CondRHS))) ||
13246 (RLD->hasAnyUseOfValue(1) &&
13247 (RLD->isPredecessorOf(CondLHS) || RLD->isPredecessorOf(CondRHS))))
13250 Addr = DAG.getNode(ISD::SELECT_CC, SDLoc(TheSelect),
13251 LLD->getBasePtr().getValueType(),
13252 TheSelect->getOperand(0),
13253 TheSelect->getOperand(1),
13254 LLD->getBasePtr(), RLD->getBasePtr(),
13255 TheSelect->getOperand(4));
13259 // It is safe to replace the two loads if they have different alignments,
13260 // but the new load must be the minimum (most restrictive) alignment of the
13262 bool isInvariant = LLD->isInvariant() & RLD->isInvariant();
13263 unsigned Alignment = std::min(LLD->getAlignment(), RLD->getAlignment());
13264 if (LLD->getExtensionType() == ISD::NON_EXTLOAD) {
13265 Load = DAG.getLoad(TheSelect->getValueType(0),
13267 // FIXME: Discards pointer and AA info.
13268 LLD->getChain(), Addr, MachinePointerInfo(),
13269 LLD->isVolatile(), LLD->isNonTemporal(),
13270 isInvariant, Alignment);
13272 Load = DAG.getExtLoad(LLD->getExtensionType() == ISD::EXTLOAD ?
13273 RLD->getExtensionType() : LLD->getExtensionType(),
13275 TheSelect->getValueType(0),
13276 // FIXME: Discards pointer and AA info.
13277 LLD->getChain(), Addr, MachinePointerInfo(),
13278 LLD->getMemoryVT(), LLD->isVolatile(),
13279 LLD->isNonTemporal(), isInvariant, Alignment);
13282 // Users of the select now use the result of the load.
13283 CombineTo(TheSelect, Load);
13285 // Users of the old loads now use the new load's chain. We know the
13286 // old-load value is dead now.
13287 CombineTo(LHS.getNode(), Load.getValue(0), Load.getValue(1));
13288 CombineTo(RHS.getNode(), Load.getValue(0), Load.getValue(1));
13295 /// Simplify an expression of the form (N0 cond N1) ? N2 : N3
13296 /// where 'cond' is the comparison specified by CC.
13297 SDValue DAGCombiner::SimplifySelectCC(SDLoc DL, SDValue N0, SDValue N1,
13298 SDValue N2, SDValue N3,
13299 ISD::CondCode CC, bool NotExtCompare) {
13300 // (x ? y : y) -> y.
13301 if (N2 == N3) return N2;
13303 EVT VT = N2.getValueType();
13304 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
13305 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.getNode());
13307 // Determine if the condition we're dealing with is constant
13308 SDValue SCC = SimplifySetCC(getSetCCResultType(N0.getValueType()),
13309 N0, N1, CC, DL, false);
13310 if (SCC.getNode()) AddToWorklist(SCC.getNode());
13312 if (ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.getNode())) {
13313 // fold select_cc true, x, y -> x
13314 // fold select_cc false, x, y -> y
13315 return !SCCC->isNullValue() ? N2 : N3;
13318 // Check to see if we can simplify the select into an fabs node
13319 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1)) {
13320 // Allow either -0.0 or 0.0
13321 if (CFP->isZero()) {
13322 // select (setg[te] X, +/-0.0), X, fneg(X) -> fabs
13323 if ((CC == ISD::SETGE || CC == ISD::SETGT) &&
13324 N0 == N2 && N3.getOpcode() == ISD::FNEG &&
13325 N2 == N3.getOperand(0))
13326 return DAG.getNode(ISD::FABS, DL, VT, N0);
13328 // select (setl[te] X, +/-0.0), fneg(X), X -> fabs
13329 if ((CC == ISD::SETLT || CC == ISD::SETLE) &&
13330 N0 == N3 && N2.getOpcode() == ISD::FNEG &&
13331 N2.getOperand(0) == N3)
13332 return DAG.getNode(ISD::FABS, DL, VT, N3);
13336 // Turn "(a cond b) ? 1.0f : 2.0f" into "load (tmp + ((a cond b) ? 0 : 4)"
13337 // where "tmp" is a constant pool entry containing an array with 1.0 and 2.0
13338 // in it. This is a win when the constant is not otherwise available because
13339 // it replaces two constant pool loads with one. We only do this if the FP
13340 // type is known to be legal, because if it isn't, then we are before legalize
13341 // types an we want the other legalization to happen first (e.g. to avoid
13342 // messing with soft float) and if the ConstantFP is not legal, because if
13343 // it is legal, we may not need to store the FP constant in a constant pool.
13344 if (ConstantFPSDNode *TV = dyn_cast<ConstantFPSDNode>(N2))
13345 if (ConstantFPSDNode *FV = dyn_cast<ConstantFPSDNode>(N3)) {
13346 if (TLI.isTypeLegal(N2.getValueType()) &&
13347 (TLI.getOperationAction(ISD::ConstantFP, N2.getValueType()) !=
13348 TargetLowering::Legal &&
13349 !TLI.isFPImmLegal(TV->getValueAPF(), TV->getValueType(0)) &&
13350 !TLI.isFPImmLegal(FV->getValueAPF(), FV->getValueType(0))) &&
13351 // If both constants have multiple uses, then we won't need to do an
13352 // extra load, they are likely around in registers for other users.
13353 (TV->hasOneUse() || FV->hasOneUse())) {
13354 Constant *Elts[] = {
13355 const_cast<ConstantFP*>(FV->getConstantFPValue()),
13356 const_cast<ConstantFP*>(TV->getConstantFPValue())
13358 Type *FPTy = Elts[0]->getType();
13359 const DataLayout &TD = *TLI.getDataLayout();
13361 // Create a ConstantArray of the two constants.
13362 Constant *CA = ConstantArray::get(ArrayType::get(FPTy, 2), Elts);
13363 SDValue CPIdx = DAG.getConstantPool(CA, TLI.getPointerTy(),
13364 TD.getPrefTypeAlignment(FPTy));
13365 unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
13367 // Get the offsets to the 0 and 1 element of the array so that we can
13368 // select between them.
13369 SDValue Zero = DAG.getIntPtrConstant(0, DL);
13370 unsigned EltSize = (unsigned)TD.getTypeAllocSize(Elts[0]->getType());
13371 SDValue One = DAG.getIntPtrConstant(EltSize, SDLoc(FV));
13373 SDValue Cond = DAG.getSetCC(DL,
13374 getSetCCResultType(N0.getValueType()),
13376 AddToWorklist(Cond.getNode());
13377 SDValue CstOffset = DAG.getSelect(DL, Zero.getValueType(),
13379 AddToWorklist(CstOffset.getNode());
13380 CPIdx = DAG.getNode(ISD::ADD, DL, CPIdx.getValueType(), CPIdx,
13382 AddToWorklist(CPIdx.getNode());
13383 return DAG.getLoad(TV->getValueType(0), DL, DAG.getEntryNode(), CPIdx,
13384 MachinePointerInfo::getConstantPool(), false,
13385 false, false, Alignment);
13389 // Check to see if we can perform the "gzip trick", transforming
13390 // (select_cc setlt X, 0, A, 0) -> (and (sra X, (sub size(X), 1), A)
13391 if (isNullConstant(N3) && CC == ISD::SETLT &&
13392 (isNullConstant(N1) || // (a < 0) ? b : 0
13393 (isOneConstant(N1) && N0 == N2))) { // (a < 1) ? a : 0
13394 EVT XType = N0.getValueType();
13395 EVT AType = N2.getValueType();
13396 if (XType.bitsGE(AType)) {
13397 // and (sra X, size(X)-1, A) -> "and (srl X, C2), A" iff A is a
13398 // single-bit constant.
13399 if (N2C && ((N2C->getAPIntValue() & (N2C->getAPIntValue() - 1)) == 0)) {
13400 unsigned ShCtV = N2C->getAPIntValue().logBase2();
13401 ShCtV = XType.getSizeInBits() - ShCtV - 1;
13402 SDValue ShCt = DAG.getConstant(ShCtV, SDLoc(N0),
13403 getShiftAmountTy(N0.getValueType()));
13404 SDValue Shift = DAG.getNode(ISD::SRL, SDLoc(N0),
13406 AddToWorklist(Shift.getNode());
13408 if (XType.bitsGT(AType)) {
13409 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
13410 AddToWorklist(Shift.getNode());
13413 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
13416 SDValue Shift = DAG.getNode(ISD::SRA, SDLoc(N0),
13418 DAG.getConstant(XType.getSizeInBits() - 1,
13420 getShiftAmountTy(N0.getValueType())));
13421 AddToWorklist(Shift.getNode());
13423 if (XType.bitsGT(AType)) {
13424 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
13425 AddToWorklist(Shift.getNode());
13428 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
13432 // fold (select_cc seteq (and x, y), 0, 0, A) -> (and (shr (shl x)) A)
13433 // where y is has a single bit set.
13434 // A plaintext description would be, we can turn the SELECT_CC into an AND
13435 // when the condition can be materialized as an all-ones register. Any
13436 // single bit-test can be materialized as an all-ones register with
13437 // shift-left and shift-right-arith.
13438 if (CC == ISD::SETEQ && N0->getOpcode() == ISD::AND &&
13439 N0->getValueType(0) == VT && isNullConstant(N1) && isNullConstant(N2)) {
13440 SDValue AndLHS = N0->getOperand(0);
13441 ConstantSDNode *ConstAndRHS = dyn_cast<ConstantSDNode>(N0->getOperand(1));
13442 if (ConstAndRHS && ConstAndRHS->getAPIntValue().countPopulation() == 1) {
13443 // Shift the tested bit over the sign bit.
13444 APInt AndMask = ConstAndRHS->getAPIntValue();
13446 DAG.getConstant(AndMask.countLeadingZeros(), SDLoc(AndLHS),
13447 getShiftAmountTy(AndLHS.getValueType()));
13448 SDValue Shl = DAG.getNode(ISD::SHL, SDLoc(N0), VT, AndLHS, ShlAmt);
13450 // Now arithmetic right shift it all the way over, so the result is either
13451 // all-ones, or zero.
13453 DAG.getConstant(AndMask.getBitWidth() - 1, SDLoc(Shl),
13454 getShiftAmountTy(Shl.getValueType()));
13455 SDValue Shr = DAG.getNode(ISD::SRA, SDLoc(N0), VT, Shl, ShrAmt);
13457 return DAG.getNode(ISD::AND, DL, VT, Shr, N3);
13461 // fold select C, 16, 0 -> shl C, 4
13462 if (N2C && isNullConstant(N3) && N2C->getAPIntValue().isPowerOf2() &&
13463 TLI.getBooleanContents(N0.getValueType()) ==
13464 TargetLowering::ZeroOrOneBooleanContent) {
13466 // If the caller doesn't want us to simplify this into a zext of a compare,
13468 if (NotExtCompare && N2C->isOne())
13471 // Get a SetCC of the condition
13472 // NOTE: Don't create a SETCC if it's not legal on this target.
13473 if (!LegalOperations ||
13474 TLI.isOperationLegal(ISD::SETCC,
13475 LegalTypes ? getSetCCResultType(N0.getValueType()) : MVT::i1)) {
13477 // cast from setcc result type to select result type
13479 SCC = DAG.getSetCC(DL, getSetCCResultType(N0.getValueType()),
13481 if (N2.getValueType().bitsLT(SCC.getValueType()))
13482 Temp = DAG.getZeroExtendInReg(SCC, SDLoc(N2),
13483 N2.getValueType());
13485 Temp = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N2),
13486 N2.getValueType(), SCC);
13488 SCC = DAG.getSetCC(SDLoc(N0), MVT::i1, N0, N1, CC);
13489 Temp = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N2),
13490 N2.getValueType(), SCC);
13493 AddToWorklist(SCC.getNode());
13494 AddToWorklist(Temp.getNode());
13499 // shl setcc result by log2 n2c
13500 return DAG.getNode(
13501 ISD::SHL, DL, N2.getValueType(), Temp,
13502 DAG.getConstant(N2C->getAPIntValue().logBase2(), SDLoc(Temp),
13503 getShiftAmountTy(Temp.getValueType())));
13507 // Check to see if this is the equivalent of setcc
13508 // FIXME: Turn all of these into setcc if setcc if setcc is legal
13509 // otherwise, go ahead with the folds.
13510 if (0 && isNullConstant(N3) && isOneConstant(N2)) {
13511 EVT XType = N0.getValueType();
13512 if (!LegalOperations ||
13513 TLI.isOperationLegal(ISD::SETCC, getSetCCResultType(XType))) {
13514 SDValue Res = DAG.getSetCC(DL, getSetCCResultType(XType), N0, N1, CC);
13515 if (Res.getValueType() != VT)
13516 Res = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Res);
13520 // fold (seteq X, 0) -> (srl (ctlz X, log2(size(X))))
13521 if (isNullConstant(N1) && CC == ISD::SETEQ &&
13522 (!LegalOperations ||
13523 TLI.isOperationLegal(ISD::CTLZ, XType))) {
13524 SDValue Ctlz = DAG.getNode(ISD::CTLZ, SDLoc(N0), XType, N0);
13525 return DAG.getNode(ISD::SRL, DL, XType, Ctlz,
13526 DAG.getConstant(Log2_32(XType.getSizeInBits()),
13528 getShiftAmountTy(Ctlz.getValueType())));
13530 // fold (setgt X, 0) -> (srl (and (-X, ~X), size(X)-1))
13531 if (isNullConstant(N1) && CC == ISD::SETGT) {
13533 SDValue NegN0 = DAG.getNode(ISD::SUB, DL,
13534 XType, DAG.getConstant(0, DL, XType), N0);
13535 SDValue NotN0 = DAG.getNOT(DL, N0, XType);
13536 return DAG.getNode(ISD::SRL, DL, XType,
13537 DAG.getNode(ISD::AND, DL, XType, NegN0, NotN0),
13538 DAG.getConstant(XType.getSizeInBits() - 1, DL,
13539 getShiftAmountTy(XType)));
13541 // fold (setgt X, -1) -> (xor (srl (X, size(X)-1), 1))
13542 if (isAllOnesConstant(N1) && CC == ISD::SETGT) {
13544 SDValue Sign = DAG.getNode(ISD::SRL, DL, XType, N0,
13545 DAG.getConstant(XType.getSizeInBits() - 1, DL,
13546 getShiftAmountTy(N0.getValueType())));
13547 return DAG.getNode(ISD::XOR, DL, XType, Sign, DAG.getConstant(1, DL,
13552 // Check to see if this is an integer abs.
13553 // select_cc setg[te] X, 0, X, -X ->
13554 // select_cc setgt X, -1, X, -X ->
13555 // select_cc setl[te] X, 0, -X, X ->
13556 // select_cc setlt X, 1, -X, X ->
13557 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
13559 ConstantSDNode *SubC = nullptr;
13560 if (((N1C->isNullValue() && (CC == ISD::SETGT || CC == ISD::SETGE)) ||
13561 (N1C->isAllOnesValue() && CC == ISD::SETGT)) &&
13562 N0 == N2 && N3.getOpcode() == ISD::SUB && N0 == N3.getOperand(1))
13563 SubC = dyn_cast<ConstantSDNode>(N3.getOperand(0));
13564 else if (((N1C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE)) ||
13565 (N1C->isOne() && CC == ISD::SETLT)) &&
13566 N0 == N3 && N2.getOpcode() == ISD::SUB && N0 == N2.getOperand(1))
13567 SubC = dyn_cast<ConstantSDNode>(N2.getOperand(0));
13569 EVT XType = N0.getValueType();
13570 if (SubC && SubC->isNullValue() && XType.isInteger()) {
13572 SDValue Shift = DAG.getNode(ISD::SRA, DL, XType,
13574 DAG.getConstant(XType.getSizeInBits() - 1, DL,
13575 getShiftAmountTy(N0.getValueType())));
13576 SDValue Add = DAG.getNode(ISD::ADD, DL,
13578 AddToWorklist(Shift.getNode());
13579 AddToWorklist(Add.getNode());
13580 return DAG.getNode(ISD::XOR, DL, XType, Add, Shift);
13587 /// This is a stub for TargetLowering::SimplifySetCC.
13588 SDValue DAGCombiner::SimplifySetCC(EVT VT, SDValue N0,
13589 SDValue N1, ISD::CondCode Cond,
13590 SDLoc DL, bool foldBooleans) {
13591 TargetLowering::DAGCombinerInfo
13592 DagCombineInfo(DAG, Level, false, this);
13593 return TLI.SimplifySetCC(VT, N0, N1, Cond, foldBooleans, DagCombineInfo, DL);
13596 /// Given an ISD::SDIV node expressing a divide by constant, return
13597 /// a DAG expression to select that will generate the same value by multiplying
13598 /// by a magic number.
13599 /// Ref: "Hacker's Delight" or "The PowerPC Compiler Writer's Guide".
13600 SDValue DAGCombiner::BuildSDIV(SDNode *N) {
13601 ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
13605 // Avoid division by zero.
13606 if (C->isNullValue())
13609 std::vector<SDNode*> Built;
13611 TLI.BuildSDIV(N, C->getAPIntValue(), DAG, LegalOperations, &Built);
13613 for (SDNode *N : Built)
13618 /// Given an ISD::SDIV node expressing a divide by constant power of 2, return a
13619 /// DAG expression that will generate the same value by right shifting.
13620 SDValue DAGCombiner::BuildSDIVPow2(SDNode *N) {
13621 ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
13625 // Avoid division by zero.
13626 if (C->isNullValue())
13629 std::vector<SDNode *> Built;
13630 SDValue S = TLI.BuildSDIVPow2(N, C->getAPIntValue(), DAG, &Built);
13632 for (SDNode *N : Built)
13637 /// Given an ISD::UDIV node expressing a divide by constant, return a DAG
13638 /// expression that will generate the same value by multiplying by a magic
13640 /// Ref: "Hacker's Delight" or "The PowerPC Compiler Writer's Guide".
13641 SDValue DAGCombiner::BuildUDIV(SDNode *N) {
13642 ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
13646 // Avoid division by zero.
13647 if (C->isNullValue())
13650 std::vector<SDNode*> Built;
13652 TLI.BuildUDIV(N, C->getAPIntValue(), DAG, LegalOperations, &Built);
13654 for (SDNode *N : Built)
13659 SDValue DAGCombiner::BuildReciprocalEstimate(SDValue Op) {
13660 if (Level >= AfterLegalizeDAG)
13663 // Expose the DAG combiner to the target combiner implementations.
13664 TargetLowering::DAGCombinerInfo DCI(DAG, Level, false, this);
13666 unsigned Iterations = 0;
13667 if (SDValue Est = TLI.getRecipEstimate(Op, DCI, Iterations)) {
13669 // Newton iteration for a function: F(X) is X_{i+1} = X_i - F(X_i)/F'(X_i)
13670 // For the reciprocal, we need to find the zero of the function:
13671 // F(X) = A X - 1 [which has a zero at X = 1/A]
13673 // X_{i+1} = X_i (2 - A X_i) = X_i + X_i (1 - A X_i) [this second form
13674 // does not require additional intermediate precision]
13675 EVT VT = Op.getValueType();
13677 SDValue FPOne = DAG.getConstantFP(1.0, DL, VT);
13679 AddToWorklist(Est.getNode());
13681 // Newton iterations: Est = Est + Est (1 - Arg * Est)
13682 for (unsigned i = 0; i < Iterations; ++i) {
13683 SDValue NewEst = DAG.getNode(ISD::FMUL, DL, VT, Op, Est);
13684 AddToWorklist(NewEst.getNode());
13686 NewEst = DAG.getNode(ISD::FSUB, DL, VT, FPOne, NewEst);
13687 AddToWorklist(NewEst.getNode());
13689 NewEst = DAG.getNode(ISD::FMUL, DL, VT, Est, NewEst);
13690 AddToWorklist(NewEst.getNode());
13692 Est = DAG.getNode(ISD::FADD, DL, VT, Est, NewEst);
13693 AddToWorklist(Est.getNode());
13702 /// Newton iteration for a function: F(X) is X_{i+1} = X_i - F(X_i)/F'(X_i)
13703 /// For the reciprocal sqrt, we need to find the zero of the function:
13704 /// F(X) = 1/X^2 - A [which has a zero at X = 1/sqrt(A)]
13706 /// X_{i+1} = X_i (1.5 - A X_i^2 / 2)
13707 /// As a result, we precompute A/2 prior to the iteration loop.
13708 SDValue DAGCombiner::BuildRsqrtNROneConst(SDValue Arg, SDValue Est,
13709 unsigned Iterations) {
13710 EVT VT = Arg.getValueType();
13712 SDValue ThreeHalves = DAG.getConstantFP(1.5, DL, VT);
13714 // We now need 0.5 * Arg which we can write as (1.5 * Arg - Arg) so that
13715 // this entire sequence requires only one FP constant.
13716 SDValue HalfArg = DAG.getNode(ISD::FMUL, DL, VT, ThreeHalves, Arg);
13717 AddToWorklist(HalfArg.getNode());
13719 HalfArg = DAG.getNode(ISD::FSUB, DL, VT, HalfArg, Arg);
13720 AddToWorklist(HalfArg.getNode());
13722 // Newton iterations: Est = Est * (1.5 - HalfArg * Est * Est)
13723 for (unsigned i = 0; i < Iterations; ++i) {
13724 SDValue NewEst = DAG.getNode(ISD::FMUL, DL, VT, Est, Est);
13725 AddToWorklist(NewEst.getNode());
13727 NewEst = DAG.getNode(ISD::FMUL, DL, VT, HalfArg, NewEst);
13728 AddToWorklist(NewEst.getNode());
13730 NewEst = DAG.getNode(ISD::FSUB, DL, VT, ThreeHalves, NewEst);
13731 AddToWorklist(NewEst.getNode());
13733 Est = DAG.getNode(ISD::FMUL, DL, VT, Est, NewEst);
13734 AddToWorklist(Est.getNode());
13739 /// Newton iteration for a function: F(X) is X_{i+1} = X_i - F(X_i)/F'(X_i)
13740 /// For the reciprocal sqrt, we need to find the zero of the function:
13741 /// F(X) = 1/X^2 - A [which has a zero at X = 1/sqrt(A)]
13743 /// X_{i+1} = (-0.5 * X_i) * (A * X_i * X_i + (-3.0))
13744 SDValue DAGCombiner::BuildRsqrtNRTwoConst(SDValue Arg, SDValue Est,
13745 unsigned Iterations) {
13746 EVT VT = Arg.getValueType();
13748 SDValue MinusThree = DAG.getConstantFP(-3.0, DL, VT);
13749 SDValue MinusHalf = DAG.getConstantFP(-0.5, DL, VT);
13751 // Newton iterations: Est = -0.5 * Est * (-3.0 + Arg * Est * Est)
13752 for (unsigned i = 0; i < Iterations; ++i) {
13753 SDValue HalfEst = DAG.getNode(ISD::FMUL, DL, VT, Est, MinusHalf);
13754 AddToWorklist(HalfEst.getNode());
13756 Est = DAG.getNode(ISD::FMUL, DL, VT, Est, Est);
13757 AddToWorklist(Est.getNode());
13759 Est = DAG.getNode(ISD::FMUL, DL, VT, Est, Arg);
13760 AddToWorklist(Est.getNode());
13762 Est = DAG.getNode(ISD::FADD, DL, VT, Est, MinusThree);
13763 AddToWorklist(Est.getNode());
13765 Est = DAG.getNode(ISD::FMUL, DL, VT, Est, HalfEst);
13766 AddToWorklist(Est.getNode());
13771 SDValue DAGCombiner::BuildRsqrtEstimate(SDValue Op) {
13772 if (Level >= AfterLegalizeDAG)
13775 // Expose the DAG combiner to the target combiner implementations.
13776 TargetLowering::DAGCombinerInfo DCI(DAG, Level, false, this);
13777 unsigned Iterations = 0;
13778 bool UseOneConstNR = false;
13779 if (SDValue Est = TLI.getRsqrtEstimate(Op, DCI, Iterations, UseOneConstNR)) {
13780 AddToWorklist(Est.getNode());
13782 Est = UseOneConstNR ?
13783 BuildRsqrtNROneConst(Op, Est, Iterations) :
13784 BuildRsqrtNRTwoConst(Op, Est, Iterations);
13792 /// Return true if base is a frame index, which is known not to alias with
13793 /// anything but itself. Provides base object and offset as results.
13794 static bool FindBaseOffset(SDValue Ptr, SDValue &Base, int64_t &Offset,
13795 const GlobalValue *&GV, const void *&CV) {
13796 // Assume it is a primitive operation.
13797 Base = Ptr; Offset = 0; GV = nullptr; CV = nullptr;
13799 // If it's an adding a simple constant then integrate the offset.
13800 if (Base.getOpcode() == ISD::ADD) {
13801 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Base.getOperand(1))) {
13802 Base = Base.getOperand(0);
13803 Offset += C->getZExtValue();
13807 // Return the underlying GlobalValue, and update the Offset. Return false
13808 // for GlobalAddressSDNode since the same GlobalAddress may be represented
13809 // by multiple nodes with different offsets.
13810 if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Base)) {
13811 GV = G->getGlobal();
13812 Offset += G->getOffset();
13816 // Return the underlying Constant value, and update the Offset. Return false
13817 // for ConstantSDNodes since the same constant pool entry may be represented
13818 // by multiple nodes with different offsets.
13819 if (ConstantPoolSDNode *C = dyn_cast<ConstantPoolSDNode>(Base)) {
13820 CV = C->isMachineConstantPoolEntry() ? (const void *)C->getMachineCPVal()
13821 : (const void *)C->getConstVal();
13822 Offset += C->getOffset();
13825 // If it's any of the following then it can't alias with anything but itself.
13826 return isa<FrameIndexSDNode>(Base);
13829 /// Return true if there is any possibility that the two addresses overlap.
13830 bool DAGCombiner::isAlias(LSBaseSDNode *Op0, LSBaseSDNode *Op1) const {
13831 // If they are the same then they must be aliases.
13832 if (Op0->getBasePtr() == Op1->getBasePtr()) return true;
13834 // If they are both volatile then they cannot be reordered.
13835 if (Op0->isVolatile() && Op1->isVolatile()) return true;
13837 // Gather base node and offset information.
13838 SDValue Base1, Base2;
13839 int64_t Offset1, Offset2;
13840 const GlobalValue *GV1, *GV2;
13841 const void *CV1, *CV2;
13842 bool isFrameIndex1 = FindBaseOffset(Op0->getBasePtr(),
13843 Base1, Offset1, GV1, CV1);
13844 bool isFrameIndex2 = FindBaseOffset(Op1->getBasePtr(),
13845 Base2, Offset2, GV2, CV2);
13847 // If they have a same base address then check to see if they overlap.
13848 if (Base1 == Base2 || (GV1 && (GV1 == GV2)) || (CV1 && (CV1 == CV2)))
13849 return !((Offset1 + (Op0->getMemoryVT().getSizeInBits() >> 3)) <= Offset2 ||
13850 (Offset2 + (Op1->getMemoryVT().getSizeInBits() >> 3)) <= Offset1);
13852 // It is possible for different frame indices to alias each other, mostly
13853 // when tail call optimization reuses return address slots for arguments.
13854 // To catch this case, look up the actual index of frame indices to compute
13855 // the real alias relationship.
13856 if (isFrameIndex1 && isFrameIndex2) {
13857 MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
13858 Offset1 += MFI->getObjectOffset(cast<FrameIndexSDNode>(Base1)->getIndex());
13859 Offset2 += MFI->getObjectOffset(cast<FrameIndexSDNode>(Base2)->getIndex());
13860 return !((Offset1 + (Op0->getMemoryVT().getSizeInBits() >> 3)) <= Offset2 ||
13861 (Offset2 + (Op1->getMemoryVT().getSizeInBits() >> 3)) <= Offset1);
13864 // Otherwise, if we know what the bases are, and they aren't identical, then
13865 // we know they cannot alias.
13866 if ((isFrameIndex1 || CV1 || GV1) && (isFrameIndex2 || CV2 || GV2))
13869 // If we know required SrcValue1 and SrcValue2 have relatively large alignment
13870 // compared to the size and offset of the access, we may be able to prove they
13871 // do not alias. This check is conservative for now to catch cases created by
13872 // splitting vector types.
13873 if ((Op0->getOriginalAlignment() == Op1->getOriginalAlignment()) &&
13874 (Op0->getSrcValueOffset() != Op1->getSrcValueOffset()) &&
13875 (Op0->getMemoryVT().getSizeInBits() >> 3 ==
13876 Op1->getMemoryVT().getSizeInBits() >> 3) &&
13877 (Op0->getOriginalAlignment() > Op0->getMemoryVT().getSizeInBits()) >> 3) {
13878 int64_t OffAlign1 = Op0->getSrcValueOffset() % Op0->getOriginalAlignment();
13879 int64_t OffAlign2 = Op1->getSrcValueOffset() % Op1->getOriginalAlignment();
13881 // There is no overlap between these relatively aligned accesses of similar
13882 // size, return no alias.
13883 if ((OffAlign1 + (Op0->getMemoryVT().getSizeInBits() >> 3)) <= OffAlign2 ||
13884 (OffAlign2 + (Op1->getMemoryVT().getSizeInBits() >> 3)) <= OffAlign1)
13888 bool UseAA = CombinerGlobalAA.getNumOccurrences() > 0
13890 : DAG.getSubtarget().useAA();
13892 if (CombinerAAOnlyFunc.getNumOccurrences() &&
13893 CombinerAAOnlyFunc != DAG.getMachineFunction().getName())
13897 Op0->getMemOperand()->getValue() && Op1->getMemOperand()->getValue()) {
13898 // Use alias analysis information.
13899 int64_t MinOffset = std::min(Op0->getSrcValueOffset(),
13900 Op1->getSrcValueOffset());
13901 int64_t Overlap1 = (Op0->getMemoryVT().getSizeInBits() >> 3) +
13902 Op0->getSrcValueOffset() - MinOffset;
13903 int64_t Overlap2 = (Op1->getMemoryVT().getSizeInBits() >> 3) +
13904 Op1->getSrcValueOffset() - MinOffset;
13905 AliasResult AAResult =
13906 AA.alias(MemoryLocation(Op0->getMemOperand()->getValue(), Overlap1,
13907 UseTBAA ? Op0->getAAInfo() : AAMDNodes()),
13908 MemoryLocation(Op1->getMemOperand()->getValue(), Overlap2,
13909 UseTBAA ? Op1->getAAInfo() : AAMDNodes()));
13910 if (AAResult == NoAlias)
13914 // Otherwise we have to assume they alias.
13918 /// Walk up chain skipping non-aliasing memory nodes,
13919 /// looking for aliasing nodes and adding them to the Aliases vector.
13920 void DAGCombiner::GatherAllAliases(SDNode *N, SDValue OriginalChain,
13921 SmallVectorImpl<SDValue> &Aliases) {
13922 SmallVector<SDValue, 8> Chains; // List of chains to visit.
13923 SmallPtrSet<SDNode *, 16> Visited; // Visited node set.
13925 // Get alias information for node.
13926 bool IsLoad = isa<LoadSDNode>(N) && !cast<LSBaseSDNode>(N)->isVolatile();
13929 Chains.push_back(OriginalChain);
13930 unsigned Depth = 0;
13932 // Look at each chain and determine if it is an alias. If so, add it to the
13933 // aliases list. If not, then continue up the chain looking for the next
13935 while (!Chains.empty()) {
13936 SDValue Chain = Chains.pop_back_val();
13938 // For TokenFactor nodes, look at each operand and only continue up the
13939 // chain until we find two aliases. If we've seen two aliases, assume we'll
13940 // find more and revert to original chain since the xform is unlikely to be
13943 // FIXME: The depth check could be made to return the last non-aliasing
13944 // chain we found before we hit a tokenfactor rather than the original
13946 if (Depth > 6 || Aliases.size() == 2) {
13948 Aliases.push_back(OriginalChain);
13952 // Don't bother if we've been before.
13953 if (!Visited.insert(Chain.getNode()).second)
13956 switch (Chain.getOpcode()) {
13957 case ISD::EntryToken:
13958 // Entry token is ideal chain operand, but handled in FindBetterChain.
13963 // Get alias information for Chain.
13964 bool IsOpLoad = isa<LoadSDNode>(Chain.getNode()) &&
13965 !cast<LSBaseSDNode>(Chain.getNode())->isVolatile();
13967 // If chain is alias then stop here.
13968 if (!(IsLoad && IsOpLoad) &&
13969 isAlias(cast<LSBaseSDNode>(N), cast<LSBaseSDNode>(Chain.getNode()))) {
13970 Aliases.push_back(Chain);
13972 // Look further up the chain.
13973 Chains.push_back(Chain.getOperand(0));
13979 case ISD::TokenFactor:
13980 // We have to check each of the operands of the token factor for "small"
13981 // token factors, so we queue them up. Adding the operands to the queue
13982 // (stack) in reverse order maintains the original order and increases the
13983 // likelihood that getNode will find a matching token factor (CSE.)
13984 if (Chain.getNumOperands() > 16) {
13985 Aliases.push_back(Chain);
13988 for (unsigned n = Chain.getNumOperands(); n;)
13989 Chains.push_back(Chain.getOperand(--n));
13994 // For all other instructions we will just have to take what we can get.
13995 Aliases.push_back(Chain);
14000 // We need to be careful here to also search for aliases through the
14001 // value operand of a store, etc. Consider the following situation:
14003 // L1 = load Token1, %52
14004 // S1 = store Token1, L1, %51
14005 // L2 = load Token1, %52+8
14006 // S2 = store Token1, L2, %51+8
14007 // Token2 = Token(S1, S2)
14008 // L3 = load Token2, %53
14009 // S3 = store Token2, L3, %52
14010 // L4 = load Token2, %53+8
14011 // S4 = store Token2, L4, %52+8
14012 // If we search for aliases of S3 (which loads address %52), and we look
14013 // only through the chain, then we'll miss the trivial dependence on L1
14014 // (which also loads from %52). We then might change all loads and
14015 // stores to use Token1 as their chain operand, which could result in
14016 // copying %53 into %52 before copying %52 into %51 (which should
14019 // The problem is, however, that searching for such data dependencies
14020 // can become expensive, and the cost is not directly related to the
14021 // chain depth. Instead, we'll rule out such configurations here by
14022 // insisting that we've visited all chain users (except for users
14023 // of the original chain, which is not necessary). When doing this,
14024 // we need to look through nodes we don't care about (otherwise, things
14025 // like register copies will interfere with trivial cases).
14027 SmallVector<const SDNode *, 16> Worklist;
14028 for (const SDNode *N : Visited)
14029 if (N != OriginalChain.getNode())
14030 Worklist.push_back(N);
14032 while (!Worklist.empty()) {
14033 const SDNode *M = Worklist.pop_back_val();
14035 // We have already visited M, and want to make sure we've visited any uses
14036 // of M that we care about. For uses that we've not visisted, and don't
14037 // care about, queue them to the worklist.
14039 for (SDNode::use_iterator UI = M->use_begin(),
14040 UIE = M->use_end(); UI != UIE; ++UI)
14041 if (UI.getUse().getValueType() == MVT::Other &&
14042 Visited.insert(*UI).second) {
14043 if (isa<MemSDNode>(*UI)) {
14044 // We've not visited this use, and we care about it (it could have an
14045 // ordering dependency with the original node).
14047 Aliases.push_back(OriginalChain);
14051 // We've not visited this use, but we don't care about it. Mark it as
14052 // visited and enqueue it to the worklist.
14053 Worklist.push_back(*UI);
14058 /// Walk up chain skipping non-aliasing memory nodes, looking for a better chain
14059 /// (aliasing node.)
14060 SDValue DAGCombiner::FindBetterChain(SDNode *N, SDValue OldChain) {
14061 SmallVector<SDValue, 8> Aliases; // Ops for replacing token factor.
14063 // Accumulate all the aliases to this node.
14064 GatherAllAliases(N, OldChain, Aliases);
14066 // If no operands then chain to entry token.
14067 if (Aliases.size() == 0)
14068 return DAG.getEntryNode();
14070 // If a single operand then chain to it. We don't need to revisit it.
14071 if (Aliases.size() == 1)
14074 // Construct a custom tailored token factor.
14075 return DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other, Aliases);
14078 /// This is the entry point for the file.
14079 void SelectionDAG::Combine(CombineLevel Level, AliasAnalysis &AA,
14080 CodeGenOpt::Level OptLevel) {
14081 /// This is the main entry point to this class.
14082 DAGCombiner(*this, AA, OptLevel).Run(Level);