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 #define DEBUG_TYPE "dagcombine"
20 #include "llvm/CodeGen/SelectionDAG.h"
21 #include "llvm/DerivedTypes.h"
22 #include "llvm/LLVMContext.h"
23 #include "llvm/CodeGen/MachineFunction.h"
24 #include "llvm/CodeGen/MachineFrameInfo.h"
25 #include "llvm/Analysis/AliasAnalysis.h"
26 #include "llvm/Target/TargetData.h"
27 #include "llvm/Target/TargetLowering.h"
28 #include "llvm/Target/TargetMachine.h"
29 #include "llvm/Target/TargetOptions.h"
30 #include "llvm/ADT/SmallPtrSet.h"
31 #include "llvm/ADT/Statistic.h"
32 #include "llvm/Support/CommandLine.h"
33 #include "llvm/Support/Debug.h"
34 #include "llvm/Support/ErrorHandling.h"
35 #include "llvm/Support/MathExtras.h"
36 #include "llvm/Support/raw_ostream.h"
40 STATISTIC(NodesCombined , "Number of dag nodes combined");
41 STATISTIC(PreIndexedNodes , "Number of pre-indexed nodes created");
42 STATISTIC(PostIndexedNodes, "Number of post-indexed nodes created");
43 STATISTIC(OpsNarrowed , "Number of load/op/store narrowed");
44 STATISTIC(LdStFP2Int , "Number of fp load/store pairs transformed to int");
48 CombinerAA("combiner-alias-analysis", cl::Hidden,
49 cl::desc("Turn on alias analysis during testing"));
52 CombinerGlobalAA("combiner-global-alias-analysis", cl::Hidden,
53 cl::desc("Include global information in alias analysis"));
55 //------------------------------ DAGCombiner ---------------------------------//
59 const TargetLowering &TLI;
61 CodeGenOpt::Level OptLevel;
65 // Worklist of all of the nodes that need to be simplified.
67 // This has the semantics that when adding to the worklist,
68 // the item added must be next to be processed. It should
69 // also only appear once. The naive approach to this takes
72 // To reduce the insert/remove time to logarithmic, we use
73 // a set and a vector to maintain our worklist.
75 // The set contains the items on the worklist, but does not
76 // maintain the order they should be visited.
78 // The vector maintains the order nodes should be visited, but may
79 // contain duplicate or removed nodes. When choosing a node to
80 // visit, we pop off the order stack until we find an item that is
81 // also in the contents set. All operations are O(log N).
82 SmallPtrSet<SDNode*, 64> WorkListContents;
83 SmallVector<SDNode*, 64> WorkListOrder;
85 // AA - Used for DAG load/store alias analysis.
88 /// AddUsersToWorkList - When an instruction is simplified, add all users of
89 /// the instruction to the work lists because they might get more simplified
92 void AddUsersToWorkList(SDNode *N) {
93 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
98 /// visit - call the node-specific routine that knows how to fold each
99 /// particular type of node.
100 SDValue visit(SDNode *N);
103 /// AddToWorkList - Add to the work list making sure its instance is at the
104 /// back (next to be processed.)
105 void AddToWorkList(SDNode *N) {
106 WorkListContents.insert(N);
107 WorkListOrder.push_back(N);
110 /// removeFromWorkList - remove all instances of N from the worklist.
112 void removeFromWorkList(SDNode *N) {
113 WorkListContents.erase(N);
116 SDValue CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
119 SDValue CombineTo(SDNode *N, SDValue Res, bool AddTo = true) {
120 return CombineTo(N, &Res, 1, AddTo);
123 SDValue CombineTo(SDNode *N, SDValue Res0, SDValue Res1,
125 SDValue To[] = { Res0, Res1 };
126 return CombineTo(N, To, 2, AddTo);
129 void CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO);
133 /// SimplifyDemandedBits - Check the specified integer node value to see if
134 /// it can be simplified or if things it uses can be simplified by bit
135 /// propagation. If so, return true.
136 bool SimplifyDemandedBits(SDValue Op) {
137 unsigned BitWidth = Op.getValueType().getScalarType().getSizeInBits();
138 APInt Demanded = APInt::getAllOnesValue(BitWidth);
139 return SimplifyDemandedBits(Op, Demanded);
142 bool SimplifyDemandedBits(SDValue Op, const APInt &Demanded);
144 bool CombineToPreIndexedLoadStore(SDNode *N);
145 bool CombineToPostIndexedLoadStore(SDNode *N);
147 void ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad);
148 SDValue PromoteOperand(SDValue Op, EVT PVT, bool &Replace);
149 SDValue SExtPromoteOperand(SDValue Op, EVT PVT);
150 SDValue ZExtPromoteOperand(SDValue Op, EVT PVT);
151 SDValue PromoteIntBinOp(SDValue Op);
152 SDValue PromoteIntShiftOp(SDValue Op);
153 SDValue PromoteExtend(SDValue Op);
154 bool PromoteLoad(SDValue Op);
156 void ExtendSetCCUses(SmallVector<SDNode*, 4> SetCCs,
157 SDValue Trunc, SDValue ExtLoad, DebugLoc DL,
158 ISD::NodeType ExtType);
160 /// combine - call the node-specific routine that knows how to fold each
161 /// particular type of node. If that doesn't do anything, try the
162 /// target-specific DAG combines.
163 SDValue combine(SDNode *N);
165 // Visitation implementation - Implement dag node combining for different
166 // node types. The semantics are as follows:
168 // SDValue.getNode() == 0 - No change was made
169 // SDValue.getNode() == N - N was replaced, is dead and has been handled.
170 // otherwise - N should be replaced by the returned Operand.
172 SDValue visitTokenFactor(SDNode *N);
173 SDValue visitMERGE_VALUES(SDNode *N);
174 SDValue visitADD(SDNode *N);
175 SDValue visitSUB(SDNode *N);
176 SDValue visitADDC(SDNode *N);
177 SDValue visitSUBC(SDNode *N);
178 SDValue visitADDE(SDNode *N);
179 SDValue visitSUBE(SDNode *N);
180 SDValue visitMUL(SDNode *N);
181 SDValue visitSDIV(SDNode *N);
182 SDValue visitUDIV(SDNode *N);
183 SDValue visitSREM(SDNode *N);
184 SDValue visitUREM(SDNode *N);
185 SDValue visitMULHU(SDNode *N);
186 SDValue visitMULHS(SDNode *N);
187 SDValue visitSMUL_LOHI(SDNode *N);
188 SDValue visitUMUL_LOHI(SDNode *N);
189 SDValue visitSMULO(SDNode *N);
190 SDValue visitUMULO(SDNode *N);
191 SDValue visitSDIVREM(SDNode *N);
192 SDValue visitUDIVREM(SDNode *N);
193 SDValue visitAND(SDNode *N);
194 SDValue visitOR(SDNode *N);
195 SDValue visitXOR(SDNode *N);
196 SDValue SimplifyVBinOp(SDNode *N);
197 SDValue SimplifyVUnaryOp(SDNode *N);
198 SDValue visitSHL(SDNode *N);
199 SDValue visitSRA(SDNode *N);
200 SDValue visitSRL(SDNode *N);
201 SDValue visitCTLZ(SDNode *N);
202 SDValue visitCTLZ_ZERO_UNDEF(SDNode *N);
203 SDValue visitCTTZ(SDNode *N);
204 SDValue visitCTTZ_ZERO_UNDEF(SDNode *N);
205 SDValue visitCTPOP(SDNode *N);
206 SDValue visitSELECT(SDNode *N);
207 SDValue visitSELECT_CC(SDNode *N);
208 SDValue visitSETCC(SDNode *N);
209 SDValue visitSIGN_EXTEND(SDNode *N);
210 SDValue visitZERO_EXTEND(SDNode *N);
211 SDValue visitANY_EXTEND(SDNode *N);
212 SDValue visitSIGN_EXTEND_INREG(SDNode *N);
213 SDValue visitTRUNCATE(SDNode *N);
214 SDValue visitBITCAST(SDNode *N);
215 SDValue visitBUILD_PAIR(SDNode *N);
216 SDValue visitFADD(SDNode *N);
217 SDValue visitFSUB(SDNode *N);
218 SDValue visitFMUL(SDNode *N);
219 SDValue visitFMA(SDNode *N);
220 SDValue visitFDIV(SDNode *N);
221 SDValue visitFREM(SDNode *N);
222 SDValue visitFCOPYSIGN(SDNode *N);
223 SDValue visitSINT_TO_FP(SDNode *N);
224 SDValue visitUINT_TO_FP(SDNode *N);
225 SDValue visitFP_TO_SINT(SDNode *N);
226 SDValue visitFP_TO_UINT(SDNode *N);
227 SDValue visitFP_ROUND(SDNode *N);
228 SDValue visitFP_ROUND_INREG(SDNode *N);
229 SDValue visitFP_EXTEND(SDNode *N);
230 SDValue visitFNEG(SDNode *N);
231 SDValue visitFABS(SDNode *N);
232 SDValue visitFCEIL(SDNode *N);
233 SDValue visitFTRUNC(SDNode *N);
234 SDValue visitFFLOOR(SDNode *N);
235 SDValue visitBRCOND(SDNode *N);
236 SDValue visitBR_CC(SDNode *N);
237 SDValue visitLOAD(SDNode *N);
238 SDValue visitSTORE(SDNode *N);
239 SDValue visitINSERT_VECTOR_ELT(SDNode *N);
240 SDValue visitEXTRACT_VECTOR_ELT(SDNode *N);
241 SDValue visitBUILD_VECTOR(SDNode *N);
242 SDValue visitCONCAT_VECTORS(SDNode *N);
243 SDValue visitEXTRACT_SUBVECTOR(SDNode *N);
244 SDValue visitVECTOR_SHUFFLE(SDNode *N);
245 SDValue visitMEMBARRIER(SDNode *N);
247 SDValue XformToShuffleWithZero(SDNode *N);
248 SDValue ReassociateOps(unsigned Opc, DebugLoc DL, SDValue LHS, SDValue RHS);
250 SDValue visitShiftByConstant(SDNode *N, unsigned Amt);
252 bool SimplifySelectOps(SDNode *SELECT, SDValue LHS, SDValue RHS);
253 SDValue SimplifyBinOpWithSameOpcodeHands(SDNode *N);
254 SDValue SimplifySelect(DebugLoc DL, SDValue N0, SDValue N1, SDValue N2);
255 SDValue SimplifySelectCC(DebugLoc DL, SDValue N0, SDValue N1, SDValue N2,
256 SDValue N3, ISD::CondCode CC,
257 bool NotExtCompare = false);
258 SDValue SimplifySetCC(EVT VT, SDValue N0, SDValue N1, ISD::CondCode Cond,
259 DebugLoc DL, bool foldBooleans = true);
260 SDValue SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
262 SDValue CombineConsecutiveLoads(SDNode *N, EVT VT);
263 SDValue ConstantFoldBITCASTofBUILD_VECTOR(SDNode *, EVT);
264 SDValue BuildSDIV(SDNode *N);
265 SDValue BuildUDIV(SDNode *N);
266 SDValue MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
267 bool DemandHighBits = true);
268 SDValue MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1);
269 SDNode *MatchRotate(SDValue LHS, SDValue RHS, DebugLoc DL);
270 SDValue ReduceLoadWidth(SDNode *N);
271 SDValue ReduceLoadOpStoreWidth(SDNode *N);
272 SDValue TransformFPLoadStorePair(SDNode *N);
274 SDValue GetDemandedBits(SDValue V, const APInt &Mask);
276 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
277 /// looking for aliasing nodes and adding them to the Aliases vector.
278 void GatherAllAliases(SDNode *N, SDValue OriginalChain,
279 SmallVector<SDValue, 8> &Aliases);
281 /// isAlias - Return true if there is any possibility that the two addresses
283 bool isAlias(SDValue Ptr1, int64_t Size1,
284 const Value *SrcValue1, int SrcValueOffset1,
285 unsigned SrcValueAlign1,
286 const MDNode *TBAAInfo1,
287 SDValue Ptr2, int64_t Size2,
288 const Value *SrcValue2, int SrcValueOffset2,
289 unsigned SrcValueAlign2,
290 const MDNode *TBAAInfo2) const;
292 /// FindAliasInfo - Extracts the relevant alias information from the memory
293 /// node. Returns true if the operand was a load.
294 bool FindAliasInfo(SDNode *N,
295 SDValue &Ptr, int64_t &Size,
296 const Value *&SrcValue, int &SrcValueOffset,
297 unsigned &SrcValueAlignment,
298 const MDNode *&TBAAInfo) const;
300 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes,
301 /// looking for a better chain (aliasing node.)
302 SDValue FindBetterChain(SDNode *N, SDValue Chain);
305 DAGCombiner(SelectionDAG &D, AliasAnalysis &A, CodeGenOpt::Level OL)
306 : DAG(D), TLI(D.getTargetLoweringInfo()), Level(BeforeLegalizeTypes),
307 OptLevel(OL), LegalOperations(false), LegalTypes(false), AA(A) {}
309 /// Run - runs the dag combiner on all nodes in the work list
310 void Run(CombineLevel AtLevel);
312 SelectionDAG &getDAG() const { return DAG; }
314 /// getShiftAmountTy - Returns a type large enough to hold any valid
315 /// shift amount - before type legalization these can be huge.
316 EVT getShiftAmountTy(EVT LHSTy) {
317 return LegalTypes ? TLI.getShiftAmountTy(LHSTy) : TLI.getPointerTy();
320 /// isTypeLegal - This method returns true if we are running before type
321 /// legalization or if the specified VT is legal.
322 bool isTypeLegal(const EVT &VT) {
323 if (!LegalTypes) return true;
324 return TLI.isTypeLegal(VT);
331 /// WorkListRemover - This class is a DAGUpdateListener that removes any deleted
332 /// nodes from the worklist.
333 class WorkListRemover : public SelectionDAG::DAGUpdateListener {
336 explicit WorkListRemover(DAGCombiner &dc)
337 : SelectionDAG::DAGUpdateListener(dc.getDAG()), DC(dc) {}
339 virtual void NodeDeleted(SDNode *N, SDNode *E) {
340 DC.removeFromWorkList(N);
345 //===----------------------------------------------------------------------===//
346 // TargetLowering::DAGCombinerInfo implementation
347 //===----------------------------------------------------------------------===//
349 void TargetLowering::DAGCombinerInfo::AddToWorklist(SDNode *N) {
350 ((DAGCombiner*)DC)->AddToWorkList(N);
353 void TargetLowering::DAGCombinerInfo::RemoveFromWorklist(SDNode *N) {
354 ((DAGCombiner*)DC)->removeFromWorkList(N);
357 SDValue TargetLowering::DAGCombinerInfo::
358 CombineTo(SDNode *N, const std::vector<SDValue> &To, bool AddTo) {
359 return ((DAGCombiner*)DC)->CombineTo(N, &To[0], To.size(), AddTo);
362 SDValue TargetLowering::DAGCombinerInfo::
363 CombineTo(SDNode *N, SDValue Res, bool AddTo) {
364 return ((DAGCombiner*)DC)->CombineTo(N, Res, AddTo);
368 SDValue TargetLowering::DAGCombinerInfo::
369 CombineTo(SDNode *N, SDValue Res0, SDValue Res1, bool AddTo) {
370 return ((DAGCombiner*)DC)->CombineTo(N, Res0, Res1, AddTo);
373 void TargetLowering::DAGCombinerInfo::
374 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
375 return ((DAGCombiner*)DC)->CommitTargetLoweringOpt(TLO);
378 //===----------------------------------------------------------------------===//
380 //===----------------------------------------------------------------------===//
382 /// isNegatibleForFree - Return 1 if we can compute the negated form of the
383 /// specified expression for the same cost as the expression itself, or 2 if we
384 /// can compute the negated form more cheaply than the expression itself.
385 static char isNegatibleForFree(SDValue Op, bool LegalOperations,
386 const TargetLowering &TLI,
387 const TargetOptions *Options,
388 unsigned Depth = 0) {
389 // No compile time optimizations on this type.
390 if (Op.getValueType() == MVT::ppcf128)
393 // fneg is removable even if it has multiple uses.
394 if (Op.getOpcode() == ISD::FNEG) return 2;
396 // Don't allow anything with multiple uses.
397 if (!Op.hasOneUse()) return 0;
399 // Don't recurse exponentially.
400 if (Depth > 6) return 0;
402 switch (Op.getOpcode()) {
403 default: return false;
404 case ISD::ConstantFP:
405 // Don't invert constant FP values after legalize. The negated constant
406 // isn't necessarily legal.
407 return LegalOperations ? 0 : 1;
409 // FIXME: determine better conditions for this xform.
410 if (!Options->UnsafeFPMath) return 0;
412 // After operation legalization, it might not be legal to create new FSUBs.
413 if (LegalOperations &&
414 !TLI.isOperationLegalOrCustom(ISD::FSUB, Op.getValueType()))
417 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
418 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
421 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
422 return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
425 // We can't turn -(A-B) into B-A when we honor signed zeros.
426 if (!Options->UnsafeFPMath) return 0;
428 // fold (fneg (fsub A, B)) -> (fsub B, A)
433 if (Options->HonorSignDependentRoundingFPMath()) return 0;
435 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y) or (fmul X, (fneg Y))
436 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
440 return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
446 return isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI, Options,
451 /// GetNegatedExpression - If isNegatibleForFree returns true, this function
452 /// returns the newly negated expression.
453 static SDValue GetNegatedExpression(SDValue Op, SelectionDAG &DAG,
454 bool LegalOperations, unsigned Depth = 0) {
455 // fneg is removable even if it has multiple uses.
456 if (Op.getOpcode() == ISD::FNEG) return Op.getOperand(0);
458 // Don't allow anything with multiple uses.
459 assert(Op.hasOneUse() && "Unknown reuse!");
461 assert(Depth <= 6 && "GetNegatedExpression doesn't match isNegatibleForFree");
462 switch (Op.getOpcode()) {
463 default: llvm_unreachable("Unknown code");
464 case ISD::ConstantFP: {
465 APFloat V = cast<ConstantFPSDNode>(Op)->getValueAPF();
467 return DAG.getConstantFP(V, Op.getValueType());
470 // FIXME: determine better conditions for this xform.
471 assert(DAG.getTarget().Options.UnsafeFPMath);
473 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
474 if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
475 DAG.getTargetLoweringInfo(),
476 &DAG.getTarget().Options, Depth+1))
477 return DAG.getNode(ISD::FSUB, Op.getDebugLoc(), Op.getValueType(),
478 GetNegatedExpression(Op.getOperand(0), DAG,
479 LegalOperations, Depth+1),
481 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
482 return DAG.getNode(ISD::FSUB, Op.getDebugLoc(), Op.getValueType(),
483 GetNegatedExpression(Op.getOperand(1), DAG,
484 LegalOperations, Depth+1),
487 // We can't turn -(A-B) into B-A when we honor signed zeros.
488 assert(DAG.getTarget().Options.UnsafeFPMath);
490 // fold (fneg (fsub 0, B)) -> B
491 if (ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(Op.getOperand(0)))
492 if (N0CFP->getValueAPF().isZero())
493 return Op.getOperand(1);
495 // fold (fneg (fsub A, B)) -> (fsub B, A)
496 return DAG.getNode(ISD::FSUB, Op.getDebugLoc(), Op.getValueType(),
497 Op.getOperand(1), Op.getOperand(0));
501 assert(!DAG.getTarget().Options.HonorSignDependentRoundingFPMath());
503 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y)
504 if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
505 DAG.getTargetLoweringInfo(),
506 &DAG.getTarget().Options, Depth+1))
507 return DAG.getNode(Op.getOpcode(), Op.getDebugLoc(), Op.getValueType(),
508 GetNegatedExpression(Op.getOperand(0), DAG,
509 LegalOperations, Depth+1),
512 // fold (fneg (fmul X, Y)) -> (fmul X, (fneg Y))
513 return DAG.getNode(Op.getOpcode(), Op.getDebugLoc(), Op.getValueType(),
515 GetNegatedExpression(Op.getOperand(1), DAG,
516 LegalOperations, Depth+1));
520 return DAG.getNode(Op.getOpcode(), Op.getDebugLoc(), Op.getValueType(),
521 GetNegatedExpression(Op.getOperand(0), DAG,
522 LegalOperations, Depth+1));
524 return DAG.getNode(ISD::FP_ROUND, Op.getDebugLoc(), Op.getValueType(),
525 GetNegatedExpression(Op.getOperand(0), DAG,
526 LegalOperations, Depth+1),
532 // isSetCCEquivalent - Return true if this node is a setcc, or is a select_cc
533 // that selects between the values 1 and 0, making it equivalent to a setcc.
534 // Also, set the incoming LHS, RHS, and CC references to the appropriate
535 // nodes based on the type of node we are checking. This simplifies life a
536 // bit for the callers.
537 static bool isSetCCEquivalent(SDValue N, SDValue &LHS, SDValue &RHS,
539 if (N.getOpcode() == ISD::SETCC) {
540 LHS = N.getOperand(0);
541 RHS = N.getOperand(1);
542 CC = N.getOperand(2);
545 if (N.getOpcode() == ISD::SELECT_CC &&
546 N.getOperand(2).getOpcode() == ISD::Constant &&
547 N.getOperand(3).getOpcode() == ISD::Constant &&
548 cast<ConstantSDNode>(N.getOperand(2))->getAPIntValue() == 1 &&
549 cast<ConstantSDNode>(N.getOperand(3))->isNullValue()) {
550 LHS = N.getOperand(0);
551 RHS = N.getOperand(1);
552 CC = N.getOperand(4);
558 // isOneUseSetCC - Return true if this is a SetCC-equivalent operation with only
559 // one use. If this is true, it allows the users to invert the operation for
560 // free when it is profitable to do so.
561 static bool isOneUseSetCC(SDValue N) {
563 if (isSetCCEquivalent(N, N0, N1, N2) && N.getNode()->hasOneUse())
568 SDValue DAGCombiner::ReassociateOps(unsigned Opc, DebugLoc DL,
569 SDValue N0, SDValue N1) {
570 EVT VT = N0.getValueType();
571 if (N0.getOpcode() == Opc && isa<ConstantSDNode>(N0.getOperand(1))) {
572 if (isa<ConstantSDNode>(N1)) {
573 // reassoc. (op (op x, c1), c2) -> (op x, (op c1, c2))
575 DAG.FoldConstantArithmetic(Opc, VT,
576 cast<ConstantSDNode>(N0.getOperand(1)),
577 cast<ConstantSDNode>(N1));
578 return DAG.getNode(Opc, DL, VT, N0.getOperand(0), OpNode);
580 if (N0.hasOneUse()) {
581 // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one use
582 SDValue OpNode = DAG.getNode(Opc, N0.getDebugLoc(), VT,
583 N0.getOperand(0), N1);
584 AddToWorkList(OpNode.getNode());
585 return DAG.getNode(Opc, DL, VT, OpNode, N0.getOperand(1));
589 if (N1.getOpcode() == Opc && isa<ConstantSDNode>(N1.getOperand(1))) {
590 if (isa<ConstantSDNode>(N0)) {
591 // reassoc. (op c2, (op x, c1)) -> (op x, (op c1, c2))
593 DAG.FoldConstantArithmetic(Opc, VT,
594 cast<ConstantSDNode>(N1.getOperand(1)),
595 cast<ConstantSDNode>(N0));
596 return DAG.getNode(Opc, DL, VT, N1.getOperand(0), OpNode);
598 if (N1.hasOneUse()) {
599 // reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) iff x+c1 has one use
600 SDValue OpNode = DAG.getNode(Opc, N0.getDebugLoc(), VT,
601 N1.getOperand(0), N0);
602 AddToWorkList(OpNode.getNode());
603 return DAG.getNode(Opc, DL, VT, OpNode, N1.getOperand(1));
610 SDValue DAGCombiner::CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
612 assert(N->getNumValues() == NumTo && "Broken CombineTo call!");
614 DEBUG(dbgs() << "\nReplacing.1 ";
616 dbgs() << "\nWith: ";
617 To[0].getNode()->dump(&DAG);
618 dbgs() << " and " << NumTo-1 << " other values\n";
619 for (unsigned i = 0, e = NumTo; i != e; ++i)
620 assert((!To[i].getNode() ||
621 N->getValueType(i) == To[i].getValueType()) &&
622 "Cannot combine value to value of different type!"));
623 WorkListRemover DeadNodes(*this);
624 DAG.ReplaceAllUsesWith(N, To);
626 // Push the new nodes and any users onto the worklist
627 for (unsigned i = 0, e = NumTo; i != e; ++i) {
628 if (To[i].getNode()) {
629 AddToWorkList(To[i].getNode());
630 AddUsersToWorkList(To[i].getNode());
635 // Finally, if the node is now dead, remove it from the graph. The node
636 // may not be dead if the replacement process recursively simplified to
637 // something else needing this node.
638 if (N->use_empty()) {
639 // Nodes can be reintroduced into the worklist. Make sure we do not
640 // process a node that has been replaced.
641 removeFromWorkList(N);
643 // Finally, since the node is now dead, remove it from the graph.
646 return SDValue(N, 0);
650 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
651 // Replace all uses. If any nodes become isomorphic to other nodes and
652 // are deleted, make sure to remove them from our worklist.
653 WorkListRemover DeadNodes(*this);
654 DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New);
656 // Push the new node and any (possibly new) users onto the worklist.
657 AddToWorkList(TLO.New.getNode());
658 AddUsersToWorkList(TLO.New.getNode());
660 // Finally, if the node is now dead, remove it from the graph. The node
661 // may not be dead if the replacement process recursively simplified to
662 // something else needing this node.
663 if (TLO.Old.getNode()->use_empty()) {
664 removeFromWorkList(TLO.Old.getNode());
666 // If the operands of this node are only used by the node, they will now
667 // be dead. Make sure to visit them first to delete dead nodes early.
668 for (unsigned i = 0, e = TLO.Old.getNode()->getNumOperands(); i != e; ++i)
669 if (TLO.Old.getNode()->getOperand(i).getNode()->hasOneUse())
670 AddToWorkList(TLO.Old.getNode()->getOperand(i).getNode());
672 DAG.DeleteNode(TLO.Old.getNode());
676 /// SimplifyDemandedBits - Check the specified integer node value to see if
677 /// it can be simplified or if things it uses can be simplified by bit
678 /// propagation. If so, return true.
679 bool DAGCombiner::SimplifyDemandedBits(SDValue Op, const APInt &Demanded) {
680 TargetLowering::TargetLoweringOpt TLO(DAG, LegalTypes, LegalOperations);
681 APInt KnownZero, KnownOne;
682 if (!TLI.SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO))
686 AddToWorkList(Op.getNode());
688 // Replace the old value with the new one.
690 DEBUG(dbgs() << "\nReplacing.2 ";
691 TLO.Old.getNode()->dump(&DAG);
692 dbgs() << "\nWith: ";
693 TLO.New.getNode()->dump(&DAG);
696 CommitTargetLoweringOpt(TLO);
700 void DAGCombiner::ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad) {
701 DebugLoc dl = Load->getDebugLoc();
702 EVT VT = Load->getValueType(0);
703 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, VT, SDValue(ExtLoad, 0));
705 DEBUG(dbgs() << "\nReplacing.9 ";
707 dbgs() << "\nWith: ";
708 Trunc.getNode()->dump(&DAG);
710 WorkListRemover DeadNodes(*this);
711 DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 0), Trunc);
712 DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 1), SDValue(ExtLoad, 1));
713 removeFromWorkList(Load);
714 DAG.DeleteNode(Load);
715 AddToWorkList(Trunc.getNode());
718 SDValue DAGCombiner::PromoteOperand(SDValue Op, EVT PVT, bool &Replace) {
720 DebugLoc dl = Op.getDebugLoc();
721 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Op)) {
722 EVT MemVT = LD->getMemoryVT();
723 ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
724 ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT) ? ISD::ZEXTLOAD
726 : LD->getExtensionType();
728 return DAG.getExtLoad(ExtType, dl, PVT,
729 LD->getChain(), LD->getBasePtr(),
730 LD->getPointerInfo(),
731 MemVT, LD->isVolatile(),
732 LD->isNonTemporal(), LD->getAlignment());
735 unsigned Opc = Op.getOpcode();
738 case ISD::AssertSext:
739 return DAG.getNode(ISD::AssertSext, dl, PVT,
740 SExtPromoteOperand(Op.getOperand(0), PVT),
742 case ISD::AssertZext:
743 return DAG.getNode(ISD::AssertZext, dl, PVT,
744 ZExtPromoteOperand(Op.getOperand(0), PVT),
746 case ISD::Constant: {
748 Op.getValueType().isByteSized() ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
749 return DAG.getNode(ExtOpc, dl, PVT, Op);
753 if (!TLI.isOperationLegal(ISD::ANY_EXTEND, PVT))
755 return DAG.getNode(ISD::ANY_EXTEND, dl, PVT, Op);
758 SDValue DAGCombiner::SExtPromoteOperand(SDValue Op, EVT PVT) {
759 if (!TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, PVT))
761 EVT OldVT = Op.getValueType();
762 DebugLoc dl = Op.getDebugLoc();
763 bool Replace = false;
764 SDValue NewOp = PromoteOperand(Op, PVT, Replace);
765 if (NewOp.getNode() == 0)
767 AddToWorkList(NewOp.getNode());
770 ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
771 return DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, NewOp.getValueType(), NewOp,
772 DAG.getValueType(OldVT));
775 SDValue DAGCombiner::ZExtPromoteOperand(SDValue Op, EVT PVT) {
776 EVT OldVT = Op.getValueType();
777 DebugLoc dl = Op.getDebugLoc();
778 bool Replace = false;
779 SDValue NewOp = PromoteOperand(Op, PVT, Replace);
780 if (NewOp.getNode() == 0)
782 AddToWorkList(NewOp.getNode());
785 ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
786 return DAG.getZeroExtendInReg(NewOp, dl, OldVT);
789 /// PromoteIntBinOp - Promote the specified integer binary operation if the
790 /// target indicates it is beneficial. e.g. On x86, it's usually better to
791 /// promote i16 operations to i32 since i16 instructions are longer.
792 SDValue DAGCombiner::PromoteIntBinOp(SDValue Op) {
793 if (!LegalOperations)
796 EVT VT = Op.getValueType();
797 if (VT.isVector() || !VT.isInteger())
800 // If operation type is 'undesirable', e.g. i16 on x86, consider
802 unsigned Opc = Op.getOpcode();
803 if (TLI.isTypeDesirableForOp(Opc, VT))
807 // Consult target whether it is a good idea to promote this operation and
808 // what's the right type to promote it to.
809 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
810 assert(PVT != VT && "Don't know what type to promote to!");
812 bool Replace0 = false;
813 SDValue N0 = Op.getOperand(0);
814 SDValue NN0 = PromoteOperand(N0, PVT, Replace0);
815 if (NN0.getNode() == 0)
818 bool Replace1 = false;
819 SDValue N1 = Op.getOperand(1);
824 NN1 = PromoteOperand(N1, PVT, Replace1);
825 if (NN1.getNode() == 0)
829 AddToWorkList(NN0.getNode());
831 AddToWorkList(NN1.getNode());
834 ReplaceLoadWithPromotedLoad(N0.getNode(), NN0.getNode());
836 ReplaceLoadWithPromotedLoad(N1.getNode(), NN1.getNode());
838 DEBUG(dbgs() << "\nPromoting ";
839 Op.getNode()->dump(&DAG));
840 DebugLoc dl = Op.getDebugLoc();
841 return DAG.getNode(ISD::TRUNCATE, dl, VT,
842 DAG.getNode(Opc, dl, PVT, NN0, NN1));
847 /// PromoteIntShiftOp - Promote the specified integer shift operation if the
848 /// target indicates it is beneficial. e.g. On x86, it's usually better to
849 /// promote i16 operations to i32 since i16 instructions are longer.
850 SDValue DAGCombiner::PromoteIntShiftOp(SDValue Op) {
851 if (!LegalOperations)
854 EVT VT = Op.getValueType();
855 if (VT.isVector() || !VT.isInteger())
858 // If operation type is 'undesirable', e.g. i16 on x86, consider
860 unsigned Opc = Op.getOpcode();
861 if (TLI.isTypeDesirableForOp(Opc, VT))
865 // Consult target whether it is a good idea to promote this operation and
866 // what's the right type to promote it to.
867 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
868 assert(PVT != VT && "Don't know what type to promote to!");
870 bool Replace = false;
871 SDValue N0 = Op.getOperand(0);
873 N0 = SExtPromoteOperand(Op.getOperand(0), PVT);
874 else if (Opc == ISD::SRL)
875 N0 = ZExtPromoteOperand(Op.getOperand(0), PVT);
877 N0 = PromoteOperand(N0, PVT, Replace);
878 if (N0.getNode() == 0)
881 AddToWorkList(N0.getNode());
883 ReplaceLoadWithPromotedLoad(Op.getOperand(0).getNode(), N0.getNode());
885 DEBUG(dbgs() << "\nPromoting ";
886 Op.getNode()->dump(&DAG));
887 DebugLoc dl = Op.getDebugLoc();
888 return DAG.getNode(ISD::TRUNCATE, dl, VT,
889 DAG.getNode(Opc, dl, PVT, N0, Op.getOperand(1)));
894 SDValue DAGCombiner::PromoteExtend(SDValue Op) {
895 if (!LegalOperations)
898 EVT VT = Op.getValueType();
899 if (VT.isVector() || !VT.isInteger())
902 // If operation type is 'undesirable', e.g. i16 on x86, consider
904 unsigned Opc = Op.getOpcode();
905 if (TLI.isTypeDesirableForOp(Opc, VT))
909 // Consult target whether it is a good idea to promote this operation and
910 // what's the right type to promote it to.
911 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
912 assert(PVT != VT && "Don't know what type to promote to!");
913 // fold (aext (aext x)) -> (aext x)
914 // fold (aext (zext x)) -> (zext x)
915 // fold (aext (sext x)) -> (sext x)
916 DEBUG(dbgs() << "\nPromoting ";
917 Op.getNode()->dump(&DAG));
918 return DAG.getNode(Op.getOpcode(), Op.getDebugLoc(), VT, Op.getOperand(0));
923 bool DAGCombiner::PromoteLoad(SDValue Op) {
924 if (!LegalOperations)
927 EVT VT = Op.getValueType();
928 if (VT.isVector() || !VT.isInteger())
931 // If operation type is 'undesirable', e.g. i16 on x86, consider
933 unsigned Opc = Op.getOpcode();
934 if (TLI.isTypeDesirableForOp(Opc, VT))
938 // Consult target whether it is a good idea to promote this operation and
939 // what's the right type to promote it to.
940 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
941 assert(PVT != VT && "Don't know what type to promote to!");
943 DebugLoc dl = Op.getDebugLoc();
944 SDNode *N = Op.getNode();
945 LoadSDNode *LD = cast<LoadSDNode>(N);
946 EVT MemVT = LD->getMemoryVT();
947 ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
948 ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT) ? ISD::ZEXTLOAD
950 : LD->getExtensionType();
951 SDValue NewLD = DAG.getExtLoad(ExtType, dl, PVT,
952 LD->getChain(), LD->getBasePtr(),
953 LD->getPointerInfo(),
954 MemVT, LD->isVolatile(),
955 LD->isNonTemporal(), LD->getAlignment());
956 SDValue Result = DAG.getNode(ISD::TRUNCATE, dl, VT, NewLD);
958 DEBUG(dbgs() << "\nPromoting ";
961 Result.getNode()->dump(&DAG);
963 WorkListRemover DeadNodes(*this);
964 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result);
965 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), NewLD.getValue(1));
966 removeFromWorkList(N);
968 AddToWorkList(Result.getNode());
975 //===----------------------------------------------------------------------===//
976 // Main DAG Combiner implementation
977 //===----------------------------------------------------------------------===//
979 void DAGCombiner::Run(CombineLevel AtLevel) {
980 // set the instance variables, so that the various visit routines may use it.
982 LegalOperations = Level >= AfterLegalizeVectorOps;
983 LegalTypes = Level >= AfterLegalizeTypes;
985 // Add all the dag nodes to the worklist.
986 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
987 E = DAG.allnodes_end(); I != E; ++I)
990 // Create a dummy node (which is not added to allnodes), that adds a reference
991 // to the root node, preventing it from being deleted, and tracking any
992 // changes of the root.
993 HandleSDNode Dummy(DAG.getRoot());
995 // The root of the dag may dangle to deleted nodes until the dag combiner is
996 // done. Set it to null to avoid confusion.
997 DAG.setRoot(SDValue());
999 // while the worklist isn't empty, find a node and
1000 // try and combine it.
1001 while (!WorkListContents.empty()) {
1003 // The WorkListOrder holds the SDNodes in order, but it may contain duplicates.
1004 // In order to avoid a linear scan, we use a set (O(log N)) to hold what the
1005 // worklist *should* contain, and check the node we want to visit is should
1006 // actually be visited.
1008 N = WorkListOrder.pop_back_val();
1009 } while (!WorkListContents.erase(N));
1011 // If N has no uses, it is dead. Make sure to revisit all N's operands once
1012 // N is deleted from the DAG, since they too may now be dead or may have a
1013 // reduced number of uses, allowing other xforms.
1014 if (N->use_empty() && N != &Dummy) {
1015 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1016 AddToWorkList(N->getOperand(i).getNode());
1022 SDValue RV = combine(N);
1024 if (RV.getNode() == 0)
1029 // If we get back the same node we passed in, rather than a new node or
1030 // zero, we know that the node must have defined multiple values and
1031 // CombineTo was used. Since CombineTo takes care of the worklist
1032 // mechanics for us, we have no work to do in this case.
1033 if (RV.getNode() == N)
1036 assert(N->getOpcode() != ISD::DELETED_NODE &&
1037 RV.getNode()->getOpcode() != ISD::DELETED_NODE &&
1038 "Node was deleted but visit returned new node!");
1040 DEBUG(dbgs() << "\nReplacing.3 ";
1042 dbgs() << "\nWith: ";
1043 RV.getNode()->dump(&DAG);
1046 // Transfer debug value.
1047 DAG.TransferDbgValues(SDValue(N, 0), RV);
1048 WorkListRemover DeadNodes(*this);
1049 if (N->getNumValues() == RV.getNode()->getNumValues())
1050 DAG.ReplaceAllUsesWith(N, RV.getNode());
1052 assert(N->getValueType(0) == RV.getValueType() &&
1053 N->getNumValues() == 1 && "Type mismatch");
1055 DAG.ReplaceAllUsesWith(N, &OpV);
1058 // Push the new node and any users onto the worklist
1059 AddToWorkList(RV.getNode());
1060 AddUsersToWorkList(RV.getNode());
1062 // Add any uses of the old node to the worklist in case this node is the
1063 // last one that uses them. They may become dead after this node is
1065 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1066 AddToWorkList(N->getOperand(i).getNode());
1068 // Finally, if the node is now dead, remove it from the graph. The node
1069 // may not be dead if the replacement process recursively simplified to
1070 // something else needing this node.
1071 if (N->use_empty()) {
1072 // Nodes can be reintroduced into the worklist. Make sure we do not
1073 // process a node that has been replaced.
1074 removeFromWorkList(N);
1076 // Finally, since the node is now dead, remove it from the graph.
1081 // If the root changed (e.g. it was a dead load, update the root).
1082 DAG.setRoot(Dummy.getValue());
1083 DAG.RemoveDeadNodes();
1086 SDValue DAGCombiner::visit(SDNode *N) {
1087 switch (N->getOpcode()) {
1089 case ISD::TokenFactor: return visitTokenFactor(N);
1090 case ISD::MERGE_VALUES: return visitMERGE_VALUES(N);
1091 case ISD::ADD: return visitADD(N);
1092 case ISD::SUB: return visitSUB(N);
1093 case ISD::ADDC: return visitADDC(N);
1094 case ISD::SUBC: return visitSUBC(N);
1095 case ISD::ADDE: return visitADDE(N);
1096 case ISD::SUBE: return visitSUBE(N);
1097 case ISD::MUL: return visitMUL(N);
1098 case ISD::SDIV: return visitSDIV(N);
1099 case ISD::UDIV: return visitUDIV(N);
1100 case ISD::SREM: return visitSREM(N);
1101 case ISD::UREM: return visitUREM(N);
1102 case ISD::MULHU: return visitMULHU(N);
1103 case ISD::MULHS: return visitMULHS(N);
1104 case ISD::SMUL_LOHI: return visitSMUL_LOHI(N);
1105 case ISD::UMUL_LOHI: return visitUMUL_LOHI(N);
1106 case ISD::SMULO: return visitSMULO(N);
1107 case ISD::UMULO: return visitUMULO(N);
1108 case ISD::SDIVREM: return visitSDIVREM(N);
1109 case ISD::UDIVREM: return visitUDIVREM(N);
1110 case ISD::AND: return visitAND(N);
1111 case ISD::OR: return visitOR(N);
1112 case ISD::XOR: return visitXOR(N);
1113 case ISD::SHL: return visitSHL(N);
1114 case ISD::SRA: return visitSRA(N);
1115 case ISD::SRL: return visitSRL(N);
1116 case ISD::CTLZ: return visitCTLZ(N);
1117 case ISD::CTLZ_ZERO_UNDEF: return visitCTLZ_ZERO_UNDEF(N);
1118 case ISD::CTTZ: return visitCTTZ(N);
1119 case ISD::CTTZ_ZERO_UNDEF: return visitCTTZ_ZERO_UNDEF(N);
1120 case ISD::CTPOP: return visitCTPOP(N);
1121 case ISD::SELECT: return visitSELECT(N);
1122 case ISD::SELECT_CC: return visitSELECT_CC(N);
1123 case ISD::SETCC: return visitSETCC(N);
1124 case ISD::SIGN_EXTEND: return visitSIGN_EXTEND(N);
1125 case ISD::ZERO_EXTEND: return visitZERO_EXTEND(N);
1126 case ISD::ANY_EXTEND: return visitANY_EXTEND(N);
1127 case ISD::SIGN_EXTEND_INREG: return visitSIGN_EXTEND_INREG(N);
1128 case ISD::TRUNCATE: return visitTRUNCATE(N);
1129 case ISD::BITCAST: return visitBITCAST(N);
1130 case ISD::BUILD_PAIR: return visitBUILD_PAIR(N);
1131 case ISD::FADD: return visitFADD(N);
1132 case ISD::FSUB: return visitFSUB(N);
1133 case ISD::FMUL: return visitFMUL(N);
1134 case ISD::FMA: return visitFMA(N);
1135 case ISD::FDIV: return visitFDIV(N);
1136 case ISD::FREM: return visitFREM(N);
1137 case ISD::FCOPYSIGN: return visitFCOPYSIGN(N);
1138 case ISD::SINT_TO_FP: return visitSINT_TO_FP(N);
1139 case ISD::UINT_TO_FP: return visitUINT_TO_FP(N);
1140 case ISD::FP_TO_SINT: return visitFP_TO_SINT(N);
1141 case ISD::FP_TO_UINT: return visitFP_TO_UINT(N);
1142 case ISD::FP_ROUND: return visitFP_ROUND(N);
1143 case ISD::FP_ROUND_INREG: return visitFP_ROUND_INREG(N);
1144 case ISD::FP_EXTEND: return visitFP_EXTEND(N);
1145 case ISD::FNEG: return visitFNEG(N);
1146 case ISD::FABS: return visitFABS(N);
1147 case ISD::FFLOOR: return visitFFLOOR(N);
1148 case ISD::FCEIL: return visitFCEIL(N);
1149 case ISD::FTRUNC: return visitFTRUNC(N);
1150 case ISD::BRCOND: return visitBRCOND(N);
1151 case ISD::BR_CC: return visitBR_CC(N);
1152 case ISD::LOAD: return visitLOAD(N);
1153 case ISD::STORE: return visitSTORE(N);
1154 case ISD::INSERT_VECTOR_ELT: return visitINSERT_VECTOR_ELT(N);
1155 case ISD::EXTRACT_VECTOR_ELT: return visitEXTRACT_VECTOR_ELT(N);
1156 case ISD::BUILD_VECTOR: return visitBUILD_VECTOR(N);
1157 case ISD::CONCAT_VECTORS: return visitCONCAT_VECTORS(N);
1158 case ISD::EXTRACT_SUBVECTOR: return visitEXTRACT_SUBVECTOR(N);
1159 case ISD::VECTOR_SHUFFLE: return visitVECTOR_SHUFFLE(N);
1160 case ISD::MEMBARRIER: return visitMEMBARRIER(N);
1165 SDValue DAGCombiner::combine(SDNode *N) {
1166 SDValue RV = visit(N);
1168 // If nothing happened, try a target-specific DAG combine.
1169 if (RV.getNode() == 0) {
1170 assert(N->getOpcode() != ISD::DELETED_NODE &&
1171 "Node was deleted but visit returned NULL!");
1173 if (N->getOpcode() >= ISD::BUILTIN_OP_END ||
1174 TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode())) {
1176 // Expose the DAG combiner to the target combiner impls.
1177 TargetLowering::DAGCombinerInfo
1178 DagCombineInfo(DAG, !LegalTypes, !LegalOperations, false, this);
1180 RV = TLI.PerformDAGCombine(N, DagCombineInfo);
1184 // If nothing happened still, try promoting the operation.
1185 if (RV.getNode() == 0) {
1186 switch (N->getOpcode()) {
1194 RV = PromoteIntBinOp(SDValue(N, 0));
1199 RV = PromoteIntShiftOp(SDValue(N, 0));
1201 case ISD::SIGN_EXTEND:
1202 case ISD::ZERO_EXTEND:
1203 case ISD::ANY_EXTEND:
1204 RV = PromoteExtend(SDValue(N, 0));
1207 if (PromoteLoad(SDValue(N, 0)))
1213 // If N is a commutative binary node, try commuting it to enable more
1215 if (RV.getNode() == 0 &&
1216 SelectionDAG::isCommutativeBinOp(N->getOpcode()) &&
1217 N->getNumValues() == 1) {
1218 SDValue N0 = N->getOperand(0);
1219 SDValue N1 = N->getOperand(1);
1221 // Constant operands are canonicalized to RHS.
1222 if (isa<ConstantSDNode>(N0) || !isa<ConstantSDNode>(N1)) {
1223 SDValue Ops[] = { N1, N0 };
1224 SDNode *CSENode = DAG.getNodeIfExists(N->getOpcode(), N->getVTList(),
1227 return SDValue(CSENode, 0);
1234 /// getInputChainForNode - Given a node, return its input chain if it has one,
1235 /// otherwise return a null sd operand.
1236 static SDValue getInputChainForNode(SDNode *N) {
1237 if (unsigned NumOps = N->getNumOperands()) {
1238 if (N->getOperand(0).getValueType() == MVT::Other)
1239 return N->getOperand(0);
1240 else if (N->getOperand(NumOps-1).getValueType() == MVT::Other)
1241 return N->getOperand(NumOps-1);
1242 for (unsigned i = 1; i < NumOps-1; ++i)
1243 if (N->getOperand(i).getValueType() == MVT::Other)
1244 return N->getOperand(i);
1249 SDValue DAGCombiner::visitTokenFactor(SDNode *N) {
1250 // If N has two operands, where one has an input chain equal to the other,
1251 // the 'other' chain is redundant.
1252 if (N->getNumOperands() == 2) {
1253 if (getInputChainForNode(N->getOperand(0).getNode()) == N->getOperand(1))
1254 return N->getOperand(0);
1255 if (getInputChainForNode(N->getOperand(1).getNode()) == N->getOperand(0))
1256 return N->getOperand(1);
1259 SmallVector<SDNode *, 8> TFs; // List of token factors to visit.
1260 SmallVector<SDValue, 8> Ops; // Ops for replacing token factor.
1261 SmallPtrSet<SDNode*, 16> SeenOps;
1262 bool Changed = false; // If we should replace this token factor.
1264 // Start out with this token factor.
1267 // Iterate through token factors. The TFs grows when new token factors are
1269 for (unsigned i = 0; i < TFs.size(); ++i) {
1270 SDNode *TF = TFs[i];
1272 // Check each of the operands.
1273 for (unsigned i = 0, ie = TF->getNumOperands(); i != ie; ++i) {
1274 SDValue Op = TF->getOperand(i);
1276 switch (Op.getOpcode()) {
1277 case ISD::EntryToken:
1278 // Entry tokens don't need to be added to the list. They are
1283 case ISD::TokenFactor:
1284 if (Op.hasOneUse() &&
1285 std::find(TFs.begin(), TFs.end(), Op.getNode()) == TFs.end()) {
1286 // Queue up for processing.
1287 TFs.push_back(Op.getNode());
1288 // Clean up in case the token factor is removed.
1289 AddToWorkList(Op.getNode());
1296 // Only add if it isn't already in the list.
1297 if (SeenOps.insert(Op.getNode()))
1308 // If we've change things around then replace token factor.
1311 // The entry token is the only possible outcome.
1312 Result = DAG.getEntryNode();
1314 // New and improved token factor.
1315 Result = DAG.getNode(ISD::TokenFactor, N->getDebugLoc(),
1316 MVT::Other, &Ops[0], Ops.size());
1319 // Don't add users to work list.
1320 return CombineTo(N, Result, false);
1326 /// MERGE_VALUES can always be eliminated.
1327 SDValue DAGCombiner::visitMERGE_VALUES(SDNode *N) {
1328 WorkListRemover DeadNodes(*this);
1329 // Replacing results may cause a different MERGE_VALUES to suddenly
1330 // be CSE'd with N, and carry its uses with it. Iterate until no
1331 // uses remain, to ensure that the node can be safely deleted.
1332 // First add the users of this node to the work list so that they
1333 // can be tried again once they have new operands.
1334 AddUsersToWorkList(N);
1336 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1337 DAG.ReplaceAllUsesOfValueWith(SDValue(N, i), N->getOperand(i));
1338 } while (!N->use_empty());
1339 removeFromWorkList(N);
1341 return SDValue(N, 0); // Return N so it doesn't get rechecked!
1345 SDValue combineShlAddConstant(DebugLoc DL, SDValue N0, SDValue N1,
1346 SelectionDAG &DAG) {
1347 EVT VT = N0.getValueType();
1348 SDValue N00 = N0.getOperand(0);
1349 SDValue N01 = N0.getOperand(1);
1350 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N01);
1352 if (N01C && N00.getOpcode() == ISD::ADD && N00.getNode()->hasOneUse() &&
1353 isa<ConstantSDNode>(N00.getOperand(1))) {
1354 // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
1355 N0 = DAG.getNode(ISD::ADD, N0.getDebugLoc(), VT,
1356 DAG.getNode(ISD::SHL, N00.getDebugLoc(), VT,
1357 N00.getOperand(0), N01),
1358 DAG.getNode(ISD::SHL, N01.getDebugLoc(), VT,
1359 N00.getOperand(1), N01));
1360 return DAG.getNode(ISD::ADD, DL, VT, N0, N1);
1366 SDValue DAGCombiner::visitADD(SDNode *N) {
1367 SDValue N0 = N->getOperand(0);
1368 SDValue N1 = N->getOperand(1);
1369 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1370 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1371 EVT VT = N0.getValueType();
1374 if (VT.isVector()) {
1375 SDValue FoldedVOp = SimplifyVBinOp(N);
1376 if (FoldedVOp.getNode()) return FoldedVOp;
1379 // fold (add x, undef) -> undef
1380 if (N0.getOpcode() == ISD::UNDEF)
1382 if (N1.getOpcode() == ISD::UNDEF)
1384 // fold (add c1, c2) -> c1+c2
1386 return DAG.FoldConstantArithmetic(ISD::ADD, VT, N0C, N1C);
1387 // canonicalize constant to RHS
1389 return DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N1, N0);
1390 // fold (add x, 0) -> x
1391 if (N1C && N1C->isNullValue())
1393 // fold (add Sym, c) -> Sym+c
1394 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1395 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA) && N1C &&
1396 GA->getOpcode() == ISD::GlobalAddress)
1397 return DAG.getGlobalAddress(GA->getGlobal(), N1C->getDebugLoc(), VT,
1399 (uint64_t)N1C->getSExtValue());
1400 // fold ((c1-A)+c2) -> (c1+c2)-A
1401 if (N1C && N0.getOpcode() == ISD::SUB)
1402 if (ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getOperand(0)))
1403 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1404 DAG.getConstant(N1C->getAPIntValue()+
1405 N0C->getAPIntValue(), VT),
1408 SDValue RADD = ReassociateOps(ISD::ADD, N->getDebugLoc(), N0, N1);
1409 if (RADD.getNode() != 0)
1411 // fold ((0-A) + B) -> B-A
1412 if (N0.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N0.getOperand(0)) &&
1413 cast<ConstantSDNode>(N0.getOperand(0))->isNullValue())
1414 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N1, N0.getOperand(1));
1415 // fold (A + (0-B)) -> A-B
1416 if (N1.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N1.getOperand(0)) &&
1417 cast<ConstantSDNode>(N1.getOperand(0))->isNullValue())
1418 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0, N1.getOperand(1));
1419 // fold (A+(B-A)) -> B
1420 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(1))
1421 return N1.getOperand(0);
1422 // fold ((B-A)+A) -> B
1423 if (N0.getOpcode() == ISD::SUB && N1 == N0.getOperand(1))
1424 return N0.getOperand(0);
1425 // fold (A+(B-(A+C))) to (B-C)
1426 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1427 N0 == N1.getOperand(1).getOperand(0))
1428 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N1.getOperand(0),
1429 N1.getOperand(1).getOperand(1));
1430 // fold (A+(B-(C+A))) to (B-C)
1431 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1432 N0 == N1.getOperand(1).getOperand(1))
1433 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N1.getOperand(0),
1434 N1.getOperand(1).getOperand(0));
1435 // fold (A+((B-A)+or-C)) to (B+or-C)
1436 if ((N1.getOpcode() == ISD::SUB || N1.getOpcode() == ISD::ADD) &&
1437 N1.getOperand(0).getOpcode() == ISD::SUB &&
1438 N0 == N1.getOperand(0).getOperand(1))
1439 return DAG.getNode(N1.getOpcode(), N->getDebugLoc(), VT,
1440 N1.getOperand(0).getOperand(0), N1.getOperand(1));
1442 // fold (A-B)+(C-D) to (A+C)-(B+D) when A or C is constant
1443 if (N0.getOpcode() == ISD::SUB && N1.getOpcode() == ISD::SUB) {
1444 SDValue N00 = N0.getOperand(0);
1445 SDValue N01 = N0.getOperand(1);
1446 SDValue N10 = N1.getOperand(0);
1447 SDValue N11 = N1.getOperand(1);
1449 if (isa<ConstantSDNode>(N00) || isa<ConstantSDNode>(N10))
1450 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1451 DAG.getNode(ISD::ADD, N0.getDebugLoc(), VT, N00, N10),
1452 DAG.getNode(ISD::ADD, N1.getDebugLoc(), VT, N01, N11));
1455 if (!VT.isVector() && SimplifyDemandedBits(SDValue(N, 0)))
1456 return SDValue(N, 0);
1458 // fold (a+b) -> (a|b) iff a and b share no bits.
1459 if (VT.isInteger() && !VT.isVector()) {
1460 APInt LHSZero, LHSOne;
1461 APInt RHSZero, RHSOne;
1462 DAG.ComputeMaskedBits(N0, LHSZero, LHSOne);
1464 if (LHSZero.getBoolValue()) {
1465 DAG.ComputeMaskedBits(N1, RHSZero, RHSOne);
1467 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1468 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1469 if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero)
1470 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N1);
1474 // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
1475 if (N0.getOpcode() == ISD::SHL && N0.getNode()->hasOneUse()) {
1476 SDValue Result = combineShlAddConstant(N->getDebugLoc(), N0, N1, DAG);
1477 if (Result.getNode()) return Result;
1479 if (N1.getOpcode() == ISD::SHL && N1.getNode()->hasOneUse()) {
1480 SDValue Result = combineShlAddConstant(N->getDebugLoc(), N1, N0, DAG);
1481 if (Result.getNode()) return Result;
1484 // fold (add x, shl(0 - y, n)) -> sub(x, shl(y, n))
1485 if (N1.getOpcode() == ISD::SHL &&
1486 N1.getOperand(0).getOpcode() == ISD::SUB)
1487 if (ConstantSDNode *C =
1488 dyn_cast<ConstantSDNode>(N1.getOperand(0).getOperand(0)))
1489 if (C->getAPIntValue() == 0)
1490 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0,
1491 DAG.getNode(ISD::SHL, N->getDebugLoc(), VT,
1492 N1.getOperand(0).getOperand(1),
1494 if (N0.getOpcode() == ISD::SHL &&
1495 N0.getOperand(0).getOpcode() == ISD::SUB)
1496 if (ConstantSDNode *C =
1497 dyn_cast<ConstantSDNode>(N0.getOperand(0).getOperand(0)))
1498 if (C->getAPIntValue() == 0)
1499 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N1,
1500 DAG.getNode(ISD::SHL, N->getDebugLoc(), VT,
1501 N0.getOperand(0).getOperand(1),
1504 if (N1.getOpcode() == ISD::AND) {
1505 SDValue AndOp0 = N1.getOperand(0);
1506 ConstantSDNode *AndOp1 = dyn_cast<ConstantSDNode>(N1->getOperand(1));
1507 unsigned NumSignBits = DAG.ComputeNumSignBits(AndOp0);
1508 unsigned DestBits = VT.getScalarType().getSizeInBits();
1510 // (add z, (and (sbbl x, x), 1)) -> (sub z, (sbbl x, x))
1511 // and similar xforms where the inner op is either ~0 or 0.
1512 if (NumSignBits == DestBits && AndOp1 && AndOp1->isOne()) {
1513 DebugLoc DL = N->getDebugLoc();
1514 return DAG.getNode(ISD::SUB, DL, VT, N->getOperand(0), AndOp0);
1518 // add (sext i1), X -> sub X, (zext i1)
1519 if (N0.getOpcode() == ISD::SIGN_EXTEND &&
1520 N0.getOperand(0).getValueType() == MVT::i1 &&
1521 !TLI.isOperationLegal(ISD::SIGN_EXTEND, MVT::i1)) {
1522 DebugLoc DL = N->getDebugLoc();
1523 SDValue ZExt = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0));
1524 return DAG.getNode(ISD::SUB, DL, VT, N1, ZExt);
1530 SDValue DAGCombiner::visitADDC(SDNode *N) {
1531 SDValue N0 = N->getOperand(0);
1532 SDValue N1 = N->getOperand(1);
1533 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1534 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1535 EVT VT = N0.getValueType();
1537 // If the flag result is dead, turn this into an ADD.
1538 if (!N->hasAnyUseOfValue(1))
1539 return CombineTo(N, DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N0, N1),
1540 DAG.getNode(ISD::CARRY_FALSE,
1541 N->getDebugLoc(), MVT::Glue));
1543 // canonicalize constant to RHS.
1545 return DAG.getNode(ISD::ADDC, N->getDebugLoc(), N->getVTList(), N1, N0);
1547 // fold (addc x, 0) -> x + no carry out
1548 if (N1C && N1C->isNullValue())
1549 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE,
1550 N->getDebugLoc(), MVT::Glue));
1552 // fold (addc a, b) -> (or a, b), CARRY_FALSE iff a and b share no bits.
1553 APInt LHSZero, LHSOne;
1554 APInt RHSZero, RHSOne;
1555 DAG.ComputeMaskedBits(N0, LHSZero, LHSOne);
1557 if (LHSZero.getBoolValue()) {
1558 DAG.ComputeMaskedBits(N1, RHSZero, RHSOne);
1560 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1561 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1562 if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero)
1563 return CombineTo(N, DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N1),
1564 DAG.getNode(ISD::CARRY_FALSE,
1565 N->getDebugLoc(), MVT::Glue));
1571 SDValue DAGCombiner::visitADDE(SDNode *N) {
1572 SDValue N0 = N->getOperand(0);
1573 SDValue N1 = N->getOperand(1);
1574 SDValue CarryIn = N->getOperand(2);
1575 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1576 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1578 // canonicalize constant to RHS
1580 return DAG.getNode(ISD::ADDE, N->getDebugLoc(), N->getVTList(),
1583 // fold (adde x, y, false) -> (addc x, y)
1584 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
1585 return DAG.getNode(ISD::ADDC, N->getDebugLoc(), N->getVTList(), N0, N1);
1590 // Since it may not be valid to emit a fold to zero for vector initializers
1591 // check if we can before folding.
1592 static SDValue tryFoldToZero(DebugLoc DL, const TargetLowering &TLI, EVT VT,
1593 SelectionDAG &DAG, bool LegalOperations) {
1594 if (!VT.isVector()) {
1595 return DAG.getConstant(0, VT);
1597 if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)) {
1598 // Produce a vector of zeros.
1599 SDValue El = DAG.getConstant(0, VT.getVectorElementType());
1600 std::vector<SDValue> Ops(VT.getVectorNumElements(), El);
1601 return DAG.getNode(ISD::BUILD_VECTOR, DL, VT,
1602 &Ops[0], Ops.size());
1607 SDValue DAGCombiner::visitSUB(SDNode *N) {
1608 SDValue N0 = N->getOperand(0);
1609 SDValue N1 = N->getOperand(1);
1610 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1611 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1612 ConstantSDNode *N1C1 = N1.getOpcode() != ISD::ADD ? 0 :
1613 dyn_cast<ConstantSDNode>(N1.getOperand(1).getNode());
1614 EVT VT = N0.getValueType();
1617 if (VT.isVector()) {
1618 SDValue FoldedVOp = SimplifyVBinOp(N);
1619 if (FoldedVOp.getNode()) return FoldedVOp;
1622 // fold (sub x, x) -> 0
1623 // FIXME: Refactor this and xor and other similar operations together.
1625 return tryFoldToZero(N->getDebugLoc(), TLI, VT, DAG, LegalOperations);
1626 // fold (sub c1, c2) -> c1-c2
1628 return DAG.FoldConstantArithmetic(ISD::SUB, VT, N0C, N1C);
1629 // fold (sub x, c) -> (add x, -c)
1631 return DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N0,
1632 DAG.getConstant(-N1C->getAPIntValue(), VT));
1633 // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1)
1634 if (N0C && N0C->isAllOnesValue())
1635 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N1, N0);
1636 // fold A-(A-B) -> B
1637 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(0))
1638 return N1.getOperand(1);
1639 // fold (A+B)-A -> B
1640 if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1)
1641 return N0.getOperand(1);
1642 // fold (A+B)-B -> A
1643 if (N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1)
1644 return N0.getOperand(0);
1645 // fold C2-(A+C1) -> (C2-C1)-A
1646 if (N1.getOpcode() == ISD::ADD && N0C && N1C1) {
1647 SDValue NewC = DAG.getConstant(N0C->getAPIntValue() - N1C1->getAPIntValue(),
1649 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, NewC,
1652 // fold ((A+(B+or-C))-B) -> A+or-C
1653 if (N0.getOpcode() == ISD::ADD &&
1654 (N0.getOperand(1).getOpcode() == ISD::SUB ||
1655 N0.getOperand(1).getOpcode() == ISD::ADD) &&
1656 N0.getOperand(1).getOperand(0) == N1)
1657 return DAG.getNode(N0.getOperand(1).getOpcode(), N->getDebugLoc(), VT,
1658 N0.getOperand(0), N0.getOperand(1).getOperand(1));
1659 // fold ((A+(C+B))-B) -> A+C
1660 if (N0.getOpcode() == ISD::ADD &&
1661 N0.getOperand(1).getOpcode() == ISD::ADD &&
1662 N0.getOperand(1).getOperand(1) == N1)
1663 return DAG.getNode(ISD::ADD, N->getDebugLoc(), VT,
1664 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1665 // fold ((A-(B-C))-C) -> A-B
1666 if (N0.getOpcode() == ISD::SUB &&
1667 N0.getOperand(1).getOpcode() == ISD::SUB &&
1668 N0.getOperand(1).getOperand(1) == N1)
1669 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1670 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1672 // If either operand of a sub is undef, the result is undef
1673 if (N0.getOpcode() == ISD::UNDEF)
1675 if (N1.getOpcode() == ISD::UNDEF)
1678 // If the relocation model supports it, consider symbol offsets.
1679 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1680 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA)) {
1681 // fold (sub Sym, c) -> Sym-c
1682 if (N1C && GA->getOpcode() == ISD::GlobalAddress)
1683 return DAG.getGlobalAddress(GA->getGlobal(), N1C->getDebugLoc(), VT,
1685 (uint64_t)N1C->getSExtValue());
1686 // fold (sub Sym+c1, Sym+c2) -> c1-c2
1687 if (GlobalAddressSDNode *GB = dyn_cast<GlobalAddressSDNode>(N1))
1688 if (GA->getGlobal() == GB->getGlobal())
1689 return DAG.getConstant((uint64_t)GA->getOffset() - GB->getOffset(),
1696 SDValue DAGCombiner::visitSUBC(SDNode *N) {
1697 SDValue N0 = N->getOperand(0);
1698 SDValue N1 = N->getOperand(1);
1699 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1700 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1701 EVT VT = N0.getValueType();
1703 // If the flag result is dead, turn this into an SUB.
1704 if (!N->hasAnyUseOfValue(1))
1705 return CombineTo(N, DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0, N1),
1706 DAG.getNode(ISD::CARRY_FALSE, N->getDebugLoc(),
1709 // fold (subc x, x) -> 0 + no borrow
1711 return CombineTo(N, DAG.getConstant(0, VT),
1712 DAG.getNode(ISD::CARRY_FALSE, N->getDebugLoc(),
1715 // fold (subc x, 0) -> x + no borrow
1716 if (N1C && N1C->isNullValue())
1717 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE, N->getDebugLoc(),
1720 // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1) + no borrow
1721 if (N0C && N0C->isAllOnesValue())
1722 return CombineTo(N, DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N1, N0),
1723 DAG.getNode(ISD::CARRY_FALSE, N->getDebugLoc(),
1729 SDValue DAGCombiner::visitSUBE(SDNode *N) {
1730 SDValue N0 = N->getOperand(0);
1731 SDValue N1 = N->getOperand(1);
1732 SDValue CarryIn = N->getOperand(2);
1734 // fold (sube x, y, false) -> (subc x, y)
1735 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
1736 return DAG.getNode(ISD::SUBC, N->getDebugLoc(), N->getVTList(), N0, N1);
1741 SDValue DAGCombiner::visitMUL(SDNode *N) {
1742 SDValue N0 = N->getOperand(0);
1743 SDValue N1 = N->getOperand(1);
1744 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1745 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1746 EVT VT = N0.getValueType();
1749 if (VT.isVector()) {
1750 SDValue FoldedVOp = SimplifyVBinOp(N);
1751 if (FoldedVOp.getNode()) return FoldedVOp;
1754 // fold (mul x, undef) -> 0
1755 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
1756 return DAG.getConstant(0, VT);
1757 // fold (mul c1, c2) -> c1*c2
1759 return DAG.FoldConstantArithmetic(ISD::MUL, VT, N0C, N1C);
1760 // canonicalize constant to RHS
1762 return DAG.getNode(ISD::MUL, N->getDebugLoc(), VT, N1, N0);
1763 // fold (mul x, 0) -> 0
1764 if (N1C && N1C->isNullValue())
1766 // fold (mul x, -1) -> 0-x
1767 if (N1C && N1C->isAllOnesValue())
1768 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1769 DAG.getConstant(0, VT), N0);
1770 // fold (mul x, (1 << c)) -> x << c
1771 if (N1C && N1C->getAPIntValue().isPowerOf2())
1772 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0,
1773 DAG.getConstant(N1C->getAPIntValue().logBase2(),
1774 getShiftAmountTy(N0.getValueType())));
1775 // fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c
1776 if (N1C && (-N1C->getAPIntValue()).isPowerOf2()) {
1777 unsigned Log2Val = (-N1C->getAPIntValue()).logBase2();
1778 // FIXME: If the input is something that is easily negated (e.g. a
1779 // single-use add), we should put the negate there.
1780 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1781 DAG.getConstant(0, VT),
1782 DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0,
1783 DAG.getConstant(Log2Val,
1784 getShiftAmountTy(N0.getValueType()))));
1786 // (mul (shl X, c1), c2) -> (mul X, c2 << c1)
1787 if (N1C && N0.getOpcode() == ISD::SHL &&
1788 isa<ConstantSDNode>(N0.getOperand(1))) {
1789 SDValue C3 = DAG.getNode(ISD::SHL, N->getDebugLoc(), VT,
1790 N1, N0.getOperand(1));
1791 AddToWorkList(C3.getNode());
1792 return DAG.getNode(ISD::MUL, N->getDebugLoc(), VT,
1793 N0.getOperand(0), C3);
1796 // Change (mul (shl X, C), Y) -> (shl (mul X, Y), C) when the shift has one
1799 SDValue Sh(0,0), Y(0,0);
1800 // Check for both (mul (shl X, C), Y) and (mul Y, (shl X, C)).
1801 if (N0.getOpcode() == ISD::SHL && isa<ConstantSDNode>(N0.getOperand(1)) &&
1802 N0.getNode()->hasOneUse()) {
1804 } else if (N1.getOpcode() == ISD::SHL &&
1805 isa<ConstantSDNode>(N1.getOperand(1)) &&
1806 N1.getNode()->hasOneUse()) {
1811 SDValue Mul = DAG.getNode(ISD::MUL, N->getDebugLoc(), VT,
1812 Sh.getOperand(0), Y);
1813 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT,
1814 Mul, Sh.getOperand(1));
1818 // fold (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2)
1819 if (N1C && N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse() &&
1820 isa<ConstantSDNode>(N0.getOperand(1)))
1821 return DAG.getNode(ISD::ADD, N->getDebugLoc(), VT,
1822 DAG.getNode(ISD::MUL, N0.getDebugLoc(), VT,
1823 N0.getOperand(0), N1),
1824 DAG.getNode(ISD::MUL, N1.getDebugLoc(), VT,
1825 N0.getOperand(1), N1));
1828 SDValue RMUL = ReassociateOps(ISD::MUL, N->getDebugLoc(), N0, N1);
1829 if (RMUL.getNode() != 0)
1835 SDValue DAGCombiner::visitSDIV(SDNode *N) {
1836 SDValue N0 = N->getOperand(0);
1837 SDValue N1 = N->getOperand(1);
1838 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1839 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1840 EVT VT = N->getValueType(0);
1843 if (VT.isVector()) {
1844 SDValue FoldedVOp = SimplifyVBinOp(N);
1845 if (FoldedVOp.getNode()) return FoldedVOp;
1848 // fold (sdiv c1, c2) -> c1/c2
1849 if (N0C && N1C && !N1C->isNullValue())
1850 return DAG.FoldConstantArithmetic(ISD::SDIV, VT, N0C, N1C);
1851 // fold (sdiv X, 1) -> X
1852 if (N1C && N1C->getAPIntValue() == 1LL)
1854 // fold (sdiv X, -1) -> 0-X
1855 if (N1C && N1C->isAllOnesValue())
1856 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1857 DAG.getConstant(0, VT), N0);
1858 // If we know the sign bits of both operands are zero, strength reduce to a
1859 // udiv instead. Handles (X&15) /s 4 -> X&15 >> 2
1860 if (!VT.isVector()) {
1861 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
1862 return DAG.getNode(ISD::UDIV, N->getDebugLoc(), N1.getValueType(),
1865 // fold (sdiv X, pow2) -> simple ops after legalize
1866 if (N1C && !N1C->isNullValue() &&
1867 (N1C->getAPIntValue().isPowerOf2() ||
1868 (-N1C->getAPIntValue()).isPowerOf2())) {
1869 // If dividing by powers of two is cheap, then don't perform the following
1871 if (TLI.isPow2DivCheap())
1874 unsigned lg2 = N1C->getAPIntValue().countTrailingZeros();
1876 // Splat the sign bit into the register
1877 SDValue SGN = DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, N0,
1878 DAG.getConstant(VT.getSizeInBits()-1,
1879 getShiftAmountTy(N0.getValueType())));
1880 AddToWorkList(SGN.getNode());
1882 // Add (N0 < 0) ? abs2 - 1 : 0;
1883 SDValue SRL = DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, SGN,
1884 DAG.getConstant(VT.getSizeInBits() - lg2,
1885 getShiftAmountTy(SGN.getValueType())));
1886 SDValue ADD = DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N0, SRL);
1887 AddToWorkList(SRL.getNode());
1888 AddToWorkList(ADD.getNode()); // Divide by pow2
1889 SDValue SRA = DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, ADD,
1890 DAG.getConstant(lg2, getShiftAmountTy(ADD.getValueType())));
1892 // If we're dividing by a positive value, we're done. Otherwise, we must
1893 // negate the result.
1894 if (N1C->getAPIntValue().isNonNegative())
1897 AddToWorkList(SRA.getNode());
1898 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1899 DAG.getConstant(0, VT), SRA);
1902 // if integer divide is expensive and we satisfy the requirements, emit an
1903 // alternate sequence.
1904 if (N1C && !N1C->isNullValue() && !TLI.isIntDivCheap()) {
1905 SDValue Op = BuildSDIV(N);
1906 if (Op.getNode()) return Op;
1910 if (N0.getOpcode() == ISD::UNDEF)
1911 return DAG.getConstant(0, VT);
1912 // X / undef -> undef
1913 if (N1.getOpcode() == ISD::UNDEF)
1919 SDValue DAGCombiner::visitUDIV(SDNode *N) {
1920 SDValue N0 = N->getOperand(0);
1921 SDValue N1 = N->getOperand(1);
1922 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1923 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1924 EVT VT = N->getValueType(0);
1927 if (VT.isVector()) {
1928 SDValue FoldedVOp = SimplifyVBinOp(N);
1929 if (FoldedVOp.getNode()) return FoldedVOp;
1932 // fold (udiv c1, c2) -> c1/c2
1933 if (N0C && N1C && !N1C->isNullValue())
1934 return DAG.FoldConstantArithmetic(ISD::UDIV, VT, N0C, N1C);
1935 // fold (udiv x, (1 << c)) -> x >>u c
1936 if (N1C && N1C->getAPIntValue().isPowerOf2())
1937 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0,
1938 DAG.getConstant(N1C->getAPIntValue().logBase2(),
1939 getShiftAmountTy(N0.getValueType())));
1940 // fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) iff c is power of 2
1941 if (N1.getOpcode() == ISD::SHL) {
1942 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
1943 if (SHC->getAPIntValue().isPowerOf2()) {
1944 EVT ADDVT = N1.getOperand(1).getValueType();
1945 SDValue Add = DAG.getNode(ISD::ADD, N->getDebugLoc(), ADDVT,
1947 DAG.getConstant(SHC->getAPIntValue()
1950 AddToWorkList(Add.getNode());
1951 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0, Add);
1955 // fold (udiv x, c) -> alternate
1956 if (N1C && !N1C->isNullValue() && !TLI.isIntDivCheap()) {
1957 SDValue Op = BuildUDIV(N);
1958 if (Op.getNode()) return Op;
1962 if (N0.getOpcode() == ISD::UNDEF)
1963 return DAG.getConstant(0, VT);
1964 // X / undef -> undef
1965 if (N1.getOpcode() == ISD::UNDEF)
1971 SDValue DAGCombiner::visitSREM(SDNode *N) {
1972 SDValue N0 = N->getOperand(0);
1973 SDValue N1 = N->getOperand(1);
1974 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1975 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1976 EVT VT = N->getValueType(0);
1978 // fold (srem c1, c2) -> c1%c2
1979 if (N0C && N1C && !N1C->isNullValue())
1980 return DAG.FoldConstantArithmetic(ISD::SREM, VT, N0C, N1C);
1981 // If we know the sign bits of both operands are zero, strength reduce to a
1982 // urem instead. Handles (X & 0x0FFFFFFF) %s 16 -> X&15
1983 if (!VT.isVector()) {
1984 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
1985 return DAG.getNode(ISD::UREM, N->getDebugLoc(), VT, N0, N1);
1988 // If X/C can be simplified by the division-by-constant logic, lower
1989 // X%C to the equivalent of X-X/C*C.
1990 if (N1C && !N1C->isNullValue()) {
1991 SDValue Div = DAG.getNode(ISD::SDIV, N->getDebugLoc(), VT, N0, N1);
1992 AddToWorkList(Div.getNode());
1993 SDValue OptimizedDiv = combine(Div.getNode());
1994 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
1995 SDValue Mul = DAG.getNode(ISD::MUL, N->getDebugLoc(), VT,
1997 SDValue Sub = DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0, Mul);
1998 AddToWorkList(Mul.getNode());
2004 if (N0.getOpcode() == ISD::UNDEF)
2005 return DAG.getConstant(0, VT);
2006 // X % undef -> undef
2007 if (N1.getOpcode() == ISD::UNDEF)
2013 SDValue DAGCombiner::visitUREM(SDNode *N) {
2014 SDValue N0 = N->getOperand(0);
2015 SDValue N1 = N->getOperand(1);
2016 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2017 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2018 EVT VT = N->getValueType(0);
2020 // fold (urem c1, c2) -> c1%c2
2021 if (N0C && N1C && !N1C->isNullValue())
2022 return DAG.FoldConstantArithmetic(ISD::UREM, VT, N0C, N1C);
2023 // fold (urem x, pow2) -> (and x, pow2-1)
2024 if (N1C && !N1C->isNullValue() && N1C->getAPIntValue().isPowerOf2())
2025 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0,
2026 DAG.getConstant(N1C->getAPIntValue()-1,VT));
2027 // fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1))
2028 if (N1.getOpcode() == ISD::SHL) {
2029 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
2030 if (SHC->getAPIntValue().isPowerOf2()) {
2032 DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N1,
2033 DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()),
2035 AddToWorkList(Add.getNode());
2036 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0, Add);
2041 // If X/C can be simplified by the division-by-constant logic, lower
2042 // X%C to the equivalent of X-X/C*C.
2043 if (N1C && !N1C->isNullValue()) {
2044 SDValue Div = DAG.getNode(ISD::UDIV, N->getDebugLoc(), VT, N0, N1);
2045 AddToWorkList(Div.getNode());
2046 SDValue OptimizedDiv = combine(Div.getNode());
2047 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
2048 SDValue Mul = DAG.getNode(ISD::MUL, N->getDebugLoc(), VT,
2050 SDValue Sub = DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0, Mul);
2051 AddToWorkList(Mul.getNode());
2057 if (N0.getOpcode() == ISD::UNDEF)
2058 return DAG.getConstant(0, VT);
2059 // X % undef -> undef
2060 if (N1.getOpcode() == ISD::UNDEF)
2066 SDValue DAGCombiner::visitMULHS(SDNode *N) {
2067 SDValue N0 = N->getOperand(0);
2068 SDValue N1 = N->getOperand(1);
2069 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2070 EVT VT = N->getValueType(0);
2071 DebugLoc DL = N->getDebugLoc();
2073 // fold (mulhs x, 0) -> 0
2074 if (N1C && N1C->isNullValue())
2076 // fold (mulhs x, 1) -> (sra x, size(x)-1)
2077 if (N1C && N1C->getAPIntValue() == 1)
2078 return DAG.getNode(ISD::SRA, N->getDebugLoc(), N0.getValueType(), N0,
2079 DAG.getConstant(N0.getValueType().getSizeInBits() - 1,
2080 getShiftAmountTy(N0.getValueType())));
2081 // fold (mulhs x, undef) -> 0
2082 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2083 return DAG.getConstant(0, VT);
2085 // If the type twice as wide is legal, transform the mulhs to a wider multiply
2087 if (VT.isSimple() && !VT.isVector()) {
2088 MVT Simple = VT.getSimpleVT();
2089 unsigned SimpleSize = Simple.getSizeInBits();
2090 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2091 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2092 N0 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N0);
2093 N1 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N1);
2094 N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
2095 N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
2096 DAG.getConstant(SimpleSize, getShiftAmountTy(N1.getValueType())));
2097 return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
2104 SDValue DAGCombiner::visitMULHU(SDNode *N) {
2105 SDValue N0 = N->getOperand(0);
2106 SDValue N1 = N->getOperand(1);
2107 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2108 EVT VT = N->getValueType(0);
2109 DebugLoc DL = N->getDebugLoc();
2111 // fold (mulhu x, 0) -> 0
2112 if (N1C && N1C->isNullValue())
2114 // fold (mulhu x, 1) -> 0
2115 if (N1C && N1C->getAPIntValue() == 1)
2116 return DAG.getConstant(0, N0.getValueType());
2117 // fold (mulhu x, undef) -> 0
2118 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2119 return DAG.getConstant(0, VT);
2121 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2123 if (VT.isSimple() && !VT.isVector()) {
2124 MVT Simple = VT.getSimpleVT();
2125 unsigned SimpleSize = Simple.getSizeInBits();
2126 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2127 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2128 N0 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N0);
2129 N1 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N1);
2130 N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
2131 N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
2132 DAG.getConstant(SimpleSize, getShiftAmountTy(N1.getValueType())));
2133 return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
2140 /// SimplifyNodeWithTwoResults - Perform optimizations common to nodes that
2141 /// compute two values. LoOp and HiOp give the opcodes for the two computations
2142 /// that are being performed. Return true if a simplification was made.
2144 SDValue DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
2146 // If the high half is not needed, just compute the low half.
2147 bool HiExists = N->hasAnyUseOfValue(1);
2149 (!LegalOperations ||
2150 TLI.isOperationLegal(LoOp, N->getValueType(0)))) {
2151 SDValue Res = DAG.getNode(LoOp, N->getDebugLoc(), N->getValueType(0),
2152 N->op_begin(), N->getNumOperands());
2153 return CombineTo(N, Res, Res);
2156 // If the low half is not needed, just compute the high half.
2157 bool LoExists = N->hasAnyUseOfValue(0);
2159 (!LegalOperations ||
2160 TLI.isOperationLegal(HiOp, N->getValueType(1)))) {
2161 SDValue Res = DAG.getNode(HiOp, N->getDebugLoc(), N->getValueType(1),
2162 N->op_begin(), N->getNumOperands());
2163 return CombineTo(N, Res, Res);
2166 // If both halves are used, return as it is.
2167 if (LoExists && HiExists)
2170 // If the two computed results can be simplified separately, separate them.
2172 SDValue Lo = DAG.getNode(LoOp, N->getDebugLoc(), N->getValueType(0),
2173 N->op_begin(), N->getNumOperands());
2174 AddToWorkList(Lo.getNode());
2175 SDValue LoOpt = combine(Lo.getNode());
2176 if (LoOpt.getNode() && LoOpt.getNode() != Lo.getNode() &&
2177 (!LegalOperations ||
2178 TLI.isOperationLegal(LoOpt.getOpcode(), LoOpt.getValueType())))
2179 return CombineTo(N, LoOpt, LoOpt);
2183 SDValue Hi = DAG.getNode(HiOp, N->getDebugLoc(), N->getValueType(1),
2184 N->op_begin(), N->getNumOperands());
2185 AddToWorkList(Hi.getNode());
2186 SDValue HiOpt = combine(Hi.getNode());
2187 if (HiOpt.getNode() && HiOpt != Hi &&
2188 (!LegalOperations ||
2189 TLI.isOperationLegal(HiOpt.getOpcode(), HiOpt.getValueType())))
2190 return CombineTo(N, HiOpt, HiOpt);
2196 SDValue DAGCombiner::visitSMUL_LOHI(SDNode *N) {
2197 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHS);
2198 if (Res.getNode()) return Res;
2200 EVT VT = N->getValueType(0);
2201 DebugLoc DL = N->getDebugLoc();
2203 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2205 if (VT.isSimple() && !VT.isVector()) {
2206 MVT Simple = VT.getSimpleVT();
2207 unsigned SimpleSize = Simple.getSizeInBits();
2208 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2209 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2210 SDValue Lo = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(0));
2211 SDValue Hi = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(1));
2212 Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
2213 // Compute the high part as N1.
2214 Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
2215 DAG.getConstant(SimpleSize, getShiftAmountTy(Lo.getValueType())));
2216 Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
2217 // Compute the low part as N0.
2218 Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
2219 return CombineTo(N, Lo, Hi);
2226 SDValue DAGCombiner::visitUMUL_LOHI(SDNode *N) {
2227 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHU);
2228 if (Res.getNode()) return Res;
2230 EVT VT = N->getValueType(0);
2231 DebugLoc DL = N->getDebugLoc();
2233 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2235 if (VT.isSimple() && !VT.isVector()) {
2236 MVT Simple = VT.getSimpleVT();
2237 unsigned SimpleSize = Simple.getSizeInBits();
2238 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2239 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2240 SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(0));
2241 SDValue Hi = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(1));
2242 Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
2243 // Compute the high part as N1.
2244 Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
2245 DAG.getConstant(SimpleSize, getShiftAmountTy(Lo.getValueType())));
2246 Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
2247 // Compute the low part as N0.
2248 Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
2249 return CombineTo(N, Lo, Hi);
2256 SDValue DAGCombiner::visitSMULO(SDNode *N) {
2257 // (smulo x, 2) -> (saddo x, x)
2258 if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
2259 if (C2->getAPIntValue() == 2)
2260 return DAG.getNode(ISD::SADDO, N->getDebugLoc(), N->getVTList(),
2261 N->getOperand(0), N->getOperand(0));
2266 SDValue DAGCombiner::visitUMULO(SDNode *N) {
2267 // (umulo x, 2) -> (uaddo x, x)
2268 if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
2269 if (C2->getAPIntValue() == 2)
2270 return DAG.getNode(ISD::UADDO, N->getDebugLoc(), N->getVTList(),
2271 N->getOperand(0), N->getOperand(0));
2276 SDValue DAGCombiner::visitSDIVREM(SDNode *N) {
2277 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::SDIV, ISD::SREM);
2278 if (Res.getNode()) return Res;
2283 SDValue DAGCombiner::visitUDIVREM(SDNode *N) {
2284 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::UDIV, ISD::UREM);
2285 if (Res.getNode()) return Res;
2290 /// SimplifyBinOpWithSameOpcodeHands - If this is a binary operator with
2291 /// two operands of the same opcode, try to simplify it.
2292 SDValue DAGCombiner::SimplifyBinOpWithSameOpcodeHands(SDNode *N) {
2293 SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
2294 EVT VT = N0.getValueType();
2295 assert(N0.getOpcode() == N1.getOpcode() && "Bad input!");
2297 // Bail early if none of these transforms apply.
2298 if (N0.getNode()->getNumOperands() == 0) return SDValue();
2300 // For each of OP in AND/OR/XOR:
2301 // fold (OP (zext x), (zext y)) -> (zext (OP x, y))
2302 // fold (OP (sext x), (sext y)) -> (sext (OP x, y))
2303 // fold (OP (aext x), (aext y)) -> (aext (OP x, y))
2304 // fold (OP (trunc x), (trunc y)) -> (trunc (OP x, y)) (if trunc isn't free)
2306 // do not sink logical op inside of a vector extend, since it may combine
2308 EVT Op0VT = N0.getOperand(0).getValueType();
2309 if ((N0.getOpcode() == ISD::ZERO_EXTEND ||
2310 N0.getOpcode() == ISD::SIGN_EXTEND ||
2311 // Avoid infinite looping with PromoteIntBinOp.
2312 (N0.getOpcode() == ISD::ANY_EXTEND &&
2313 (!LegalTypes || TLI.isTypeDesirableForOp(N->getOpcode(), Op0VT))) ||
2314 (N0.getOpcode() == ISD::TRUNCATE &&
2315 (!TLI.isZExtFree(VT, Op0VT) ||
2316 !TLI.isTruncateFree(Op0VT, VT)) &&
2317 TLI.isTypeLegal(Op0VT))) &&
2319 Op0VT == N1.getOperand(0).getValueType() &&
2320 (!LegalOperations || TLI.isOperationLegal(N->getOpcode(), Op0VT))) {
2321 SDValue ORNode = DAG.getNode(N->getOpcode(), N0.getDebugLoc(),
2322 N0.getOperand(0).getValueType(),
2323 N0.getOperand(0), N1.getOperand(0));
2324 AddToWorkList(ORNode.getNode());
2325 return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT, ORNode);
2328 // For each of OP in SHL/SRL/SRA/AND...
2329 // fold (and (OP x, z), (OP y, z)) -> (OP (and x, y), z)
2330 // fold (or (OP x, z), (OP y, z)) -> (OP (or x, y), z)
2331 // fold (xor (OP x, z), (OP y, z)) -> (OP (xor x, y), z)
2332 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL ||
2333 N0.getOpcode() == ISD::SRA || N0.getOpcode() == ISD::AND) &&
2334 N0.getOperand(1) == N1.getOperand(1)) {
2335 SDValue ORNode = DAG.getNode(N->getOpcode(), N0.getDebugLoc(),
2336 N0.getOperand(0).getValueType(),
2337 N0.getOperand(0), N1.getOperand(0));
2338 AddToWorkList(ORNode.getNode());
2339 return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT,
2340 ORNode, N0.getOperand(1));
2343 // Simplify xor/and/or (bitcast(A), bitcast(B)) -> bitcast(op (A,B))
2344 // Only perform this optimization after type legalization and before
2345 // LegalizeVectorOprs. LegalizeVectorOprs promotes vector operations by
2346 // adding bitcasts. For example (xor v4i32) is promoted to (v2i64), and
2347 // we don't want to undo this promotion.
2348 // We also handle SCALAR_TO_VECTOR because xor/or/and operations are cheaper
2350 if ((N0.getOpcode() == ISD::BITCAST ||
2351 N0.getOpcode() == ISD::SCALAR_TO_VECTOR) &&
2352 Level == AfterLegalizeTypes) {
2353 SDValue In0 = N0.getOperand(0);
2354 SDValue In1 = N1.getOperand(0);
2355 EVT In0Ty = In0.getValueType();
2356 EVT In1Ty = In1.getValueType();
2357 DebugLoc DL = N->getDebugLoc();
2358 // If both incoming values are integers, and the original types are the
2360 if (In0Ty.isInteger() && In1Ty.isInteger() && In0Ty == In1Ty) {
2361 SDValue Op = DAG.getNode(N->getOpcode(), DL, In0Ty, In0, In1);
2362 SDValue BC = DAG.getNode(N0.getOpcode(), DL, VT, Op);
2363 AddToWorkList(Op.getNode());
2368 // Xor/and/or are indifferent to the swizzle operation (shuffle of one value).
2369 // Simplify xor/and/or (shuff(A), shuff(B)) -> shuff(op (A,B))
2370 // If both shuffles use the same mask, and both shuffle within a single
2371 // vector, then it is worthwhile to move the swizzle after the operation.
2372 // The type-legalizer generates this pattern when loading illegal
2373 // vector types from memory. In many cases this allows additional shuffle
2375 if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
2376 N0.getOperand(1).getOpcode() == ISD::UNDEF &&
2377 N1.getOperand(1).getOpcode() == ISD::UNDEF) {
2378 ShuffleVectorSDNode *SVN0 = cast<ShuffleVectorSDNode>(N0);
2379 ShuffleVectorSDNode *SVN1 = cast<ShuffleVectorSDNode>(N1);
2381 assert(N0.getOperand(0).getValueType() == N1.getOperand(1).getValueType() &&
2382 "Inputs to shuffles are not the same type");
2384 unsigned NumElts = VT.getVectorNumElements();
2386 // Check that both shuffles use the same mask. The masks are known to be of
2387 // the same length because the result vector type is the same.
2388 bool SameMask = true;
2389 for (unsigned i = 0; i != NumElts; ++i) {
2390 int Idx0 = SVN0->getMaskElt(i);
2391 int Idx1 = SVN1->getMaskElt(i);
2399 SDValue Op = DAG.getNode(N->getOpcode(), N->getDebugLoc(), VT,
2400 N0.getOperand(0), N1.getOperand(0));
2401 AddToWorkList(Op.getNode());
2402 return DAG.getVectorShuffle(VT, N->getDebugLoc(), Op,
2403 DAG.getUNDEF(VT), &SVN0->getMask()[0]);
2410 SDValue DAGCombiner::visitAND(SDNode *N) {
2411 SDValue N0 = N->getOperand(0);
2412 SDValue N1 = N->getOperand(1);
2413 SDValue LL, LR, RL, RR, CC0, CC1;
2414 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2415 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2416 EVT VT = N1.getValueType();
2417 unsigned BitWidth = VT.getScalarType().getSizeInBits();
2420 if (VT.isVector()) {
2421 SDValue FoldedVOp = SimplifyVBinOp(N);
2422 if (FoldedVOp.getNode()) return FoldedVOp;
2425 // fold (and x, undef) -> 0
2426 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2427 return DAG.getConstant(0, VT);
2428 // fold (and c1, c2) -> c1&c2
2430 return DAG.FoldConstantArithmetic(ISD::AND, VT, N0C, N1C);
2431 // canonicalize constant to RHS
2433 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N1, N0);
2434 // fold (and x, -1) -> x
2435 if (N1C && N1C->isAllOnesValue())
2437 // if (and x, c) is known to be zero, return 0
2438 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
2439 APInt::getAllOnesValue(BitWidth)))
2440 return DAG.getConstant(0, VT);
2442 SDValue RAND = ReassociateOps(ISD::AND, N->getDebugLoc(), N0, N1);
2443 if (RAND.getNode() != 0)
2445 // fold (and (or x, C), D) -> D if (C & D) == D
2446 if (N1C && N0.getOpcode() == ISD::OR)
2447 if (ConstantSDNode *ORI = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
2448 if ((ORI->getAPIntValue() & N1C->getAPIntValue()) == N1C->getAPIntValue())
2450 // fold (and (any_ext V), c) -> (zero_ext V) if 'and' only clears top bits.
2451 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
2452 SDValue N0Op0 = N0.getOperand(0);
2453 APInt Mask = ~N1C->getAPIntValue();
2454 Mask = Mask.trunc(N0Op0.getValueSizeInBits());
2455 if (DAG.MaskedValueIsZero(N0Op0, Mask)) {
2456 SDValue Zext = DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(),
2457 N0.getValueType(), N0Op0);
2459 // Replace uses of the AND with uses of the Zero extend node.
2462 // We actually want to replace all uses of the any_extend with the
2463 // zero_extend, to avoid duplicating things. This will later cause this
2464 // AND to be folded.
2465 CombineTo(N0.getNode(), Zext);
2466 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2469 // similarly fold (and (X (load ([non_ext|any_ext|zero_ext] V))), c) ->
2470 // (X (load ([non_ext|zero_ext] V))) if 'and' only clears top bits which must
2471 // already be zero by virtue of the width of the base type of the load.
2473 // the 'X' node here can either be nothing or an extract_vector_elt to catch
2475 if ((N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
2476 N0.getOperand(0).getOpcode() == ISD::LOAD) ||
2477 N0.getOpcode() == ISD::LOAD) {
2478 LoadSDNode *Load = cast<LoadSDNode>( (N0.getOpcode() == ISD::LOAD) ?
2479 N0 : N0.getOperand(0) );
2481 // Get the constant (if applicable) the zero'th operand is being ANDed with.
2482 // This can be a pure constant or a vector splat, in which case we treat the
2483 // vector as a scalar and use the splat value.
2484 APInt Constant = APInt::getNullValue(1);
2485 if (const ConstantSDNode *C = dyn_cast<ConstantSDNode>(N1)) {
2486 Constant = C->getAPIntValue();
2487 } else if (BuildVectorSDNode *Vector = dyn_cast<BuildVectorSDNode>(N1)) {
2488 APInt SplatValue, SplatUndef;
2489 unsigned SplatBitSize;
2491 bool IsSplat = Vector->isConstantSplat(SplatValue, SplatUndef,
2492 SplatBitSize, HasAnyUndefs);
2494 // Undef bits can contribute to a possible optimisation if set, so
2496 SplatValue |= SplatUndef;
2498 // The splat value may be something like "0x00FFFFFF", which means 0 for
2499 // the first vector value and FF for the rest, repeating. We need a mask
2500 // that will apply equally to all members of the vector, so AND all the
2501 // lanes of the constant together.
2502 EVT VT = Vector->getValueType(0);
2503 unsigned BitWidth = VT.getVectorElementType().getSizeInBits();
2505 // If the splat value has been compressed to a bitlength lower
2506 // than the size of the vector lane, we need to re-expand it to
2508 if (BitWidth > SplatBitSize)
2509 for (SplatValue = SplatValue.zextOrTrunc(BitWidth);
2510 SplatBitSize < BitWidth;
2511 SplatBitSize = SplatBitSize * 2)
2512 SplatValue |= SplatValue.shl(SplatBitSize);
2514 Constant = APInt::getAllOnesValue(BitWidth);
2515 for (unsigned i = 0, n = SplatBitSize/BitWidth; i < n; ++i)
2516 Constant &= SplatValue.lshr(i*BitWidth).zextOrTrunc(BitWidth);
2520 // If we want to change an EXTLOAD to a ZEXTLOAD, ensure a ZEXTLOAD is
2521 // actually legal and isn't going to get expanded, else this is a false
2523 bool CanZextLoadProfitably = TLI.isLoadExtLegal(ISD::ZEXTLOAD,
2524 Load->getMemoryVT());
2526 // Resize the constant to the same size as the original memory access before
2527 // extension. If it is still the AllOnesValue then this AND is completely
2530 Constant.zextOrTrunc(Load->getMemoryVT().getScalarType().getSizeInBits());
2533 switch (Load->getExtensionType()) {
2534 default: B = false; break;
2535 case ISD::EXTLOAD: B = CanZextLoadProfitably; break;
2537 case ISD::NON_EXTLOAD: B = true; break;
2540 if (B && Constant.isAllOnesValue()) {
2541 // If the load type was an EXTLOAD, convert to ZEXTLOAD in order to
2542 // preserve semantics once we get rid of the AND.
2543 SDValue NewLoad(Load, 0);
2544 if (Load->getExtensionType() == ISD::EXTLOAD) {
2545 NewLoad = DAG.getLoad(Load->getAddressingMode(), ISD::ZEXTLOAD,
2546 Load->getValueType(0), Load->getDebugLoc(),
2547 Load->getChain(), Load->getBasePtr(),
2548 Load->getOffset(), Load->getMemoryVT(),
2549 Load->getMemOperand());
2550 // Replace uses of the EXTLOAD with the new ZEXTLOAD.
2551 if (Load->getNumValues() == 3) {
2552 // PRE/POST_INC loads have 3 values.
2553 SDValue To[] = { NewLoad.getValue(0), NewLoad.getValue(1),
2554 NewLoad.getValue(2) };
2555 CombineTo(Load, To, 3, true);
2557 CombineTo(Load, NewLoad.getValue(0), NewLoad.getValue(1));
2561 // Fold the AND away, taking care not to fold to the old load node if we
2563 CombineTo(N, (N0.getNode() == Load) ? NewLoad : N0);
2565 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2568 // fold (and (setcc x), (setcc y)) -> (setcc (and x, y))
2569 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
2570 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
2571 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
2573 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
2574 LL.getValueType().isInteger()) {
2575 // fold (and (seteq X, 0), (seteq Y, 0)) -> (seteq (or X, Y), 0)
2576 if (cast<ConstantSDNode>(LR)->isNullValue() && Op1 == ISD::SETEQ) {
2577 SDValue ORNode = DAG.getNode(ISD::OR, N0.getDebugLoc(),
2578 LR.getValueType(), LL, RL);
2579 AddToWorkList(ORNode.getNode());
2580 return DAG.getSetCC(N->getDebugLoc(), VT, ORNode, LR, Op1);
2582 // fold (and (seteq X, -1), (seteq Y, -1)) -> (seteq (and X, Y), -1)
2583 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETEQ) {
2584 SDValue ANDNode = DAG.getNode(ISD::AND, N0.getDebugLoc(),
2585 LR.getValueType(), LL, RL);
2586 AddToWorkList(ANDNode.getNode());
2587 return DAG.getSetCC(N->getDebugLoc(), VT, ANDNode, LR, Op1);
2589 // fold (and (setgt X, -1), (setgt Y, -1)) -> (setgt (or X, Y), -1)
2590 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETGT) {
2591 SDValue ORNode = DAG.getNode(ISD::OR, N0.getDebugLoc(),
2592 LR.getValueType(), LL, RL);
2593 AddToWorkList(ORNode.getNode());
2594 return DAG.getSetCC(N->getDebugLoc(), VT, ORNode, LR, Op1);
2597 // canonicalize equivalent to ll == rl
2598 if (LL == RR && LR == RL) {
2599 Op1 = ISD::getSetCCSwappedOperands(Op1);
2602 if (LL == RL && LR == RR) {
2603 bool isInteger = LL.getValueType().isInteger();
2604 ISD::CondCode Result = ISD::getSetCCAndOperation(Op0, Op1, isInteger);
2605 if (Result != ISD::SETCC_INVALID &&
2606 (!LegalOperations || TLI.isCondCodeLegal(Result, LL.getValueType())))
2607 return DAG.getSetCC(N->getDebugLoc(), N0.getValueType(),
2612 // Simplify: (and (op x...), (op y...)) -> (op (and x, y))
2613 if (N0.getOpcode() == N1.getOpcode()) {
2614 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
2615 if (Tmp.getNode()) return Tmp;
2618 // fold (and (sign_extend_inreg x, i16 to i32), 1) -> (and x, 1)
2619 // fold (and (sra)) -> (and (srl)) when possible.
2620 if (!VT.isVector() &&
2621 SimplifyDemandedBits(SDValue(N, 0)))
2622 return SDValue(N, 0);
2624 // fold (zext_inreg (extload x)) -> (zextload x)
2625 if (ISD::isEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode())) {
2626 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2627 EVT MemVT = LN0->getMemoryVT();
2628 // If we zero all the possible extended bits, then we can turn this into
2629 // a zextload if we are running before legalize or the operation is legal.
2630 unsigned BitWidth = N1.getValueType().getScalarType().getSizeInBits();
2631 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
2632 BitWidth - MemVT.getScalarType().getSizeInBits())) &&
2633 ((!LegalOperations && !LN0->isVolatile()) ||
2634 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT))) {
2635 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, N0.getDebugLoc(), VT,
2636 LN0->getChain(), LN0->getBasePtr(),
2637 LN0->getPointerInfo(), MemVT,
2638 LN0->isVolatile(), LN0->isNonTemporal(),
2639 LN0->getAlignment());
2641 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
2642 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2645 // fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use
2646 if (ISD::isSEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
2648 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2649 EVT MemVT = LN0->getMemoryVT();
2650 // If we zero all the possible extended bits, then we can turn this into
2651 // a zextload if we are running before legalize or the operation is legal.
2652 unsigned BitWidth = N1.getValueType().getScalarType().getSizeInBits();
2653 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
2654 BitWidth - MemVT.getScalarType().getSizeInBits())) &&
2655 ((!LegalOperations && !LN0->isVolatile()) ||
2656 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT))) {
2657 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, N0.getDebugLoc(), VT,
2659 LN0->getBasePtr(), LN0->getPointerInfo(),
2661 LN0->isVolatile(), LN0->isNonTemporal(),
2662 LN0->getAlignment());
2664 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
2665 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2669 // fold (and (load x), 255) -> (zextload x, i8)
2670 // fold (and (extload x, i16), 255) -> (zextload x, i8)
2671 // fold (and (any_ext (extload x, i16)), 255) -> (zextload x, i8)
2672 if (N1C && (N0.getOpcode() == ISD::LOAD ||
2673 (N0.getOpcode() == ISD::ANY_EXTEND &&
2674 N0.getOperand(0).getOpcode() == ISD::LOAD))) {
2675 bool HasAnyExt = N0.getOpcode() == ISD::ANY_EXTEND;
2676 LoadSDNode *LN0 = HasAnyExt
2677 ? cast<LoadSDNode>(N0.getOperand(0))
2678 : cast<LoadSDNode>(N0);
2679 if (LN0->getExtensionType() != ISD::SEXTLOAD &&
2680 LN0->isUnindexed() && N0.hasOneUse() && LN0->hasOneUse()) {
2681 uint32_t ActiveBits = N1C->getAPIntValue().getActiveBits();
2682 if (ActiveBits > 0 && APIntOps::isMask(ActiveBits, N1C->getAPIntValue())){
2683 EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), ActiveBits);
2684 EVT LoadedVT = LN0->getMemoryVT();
2686 if (ExtVT == LoadedVT &&
2687 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, ExtVT))) {
2688 EVT LoadResultTy = HasAnyExt ? LN0->getValueType(0) : VT;
2691 DAG.getExtLoad(ISD::ZEXTLOAD, LN0->getDebugLoc(), LoadResultTy,
2692 LN0->getChain(), LN0->getBasePtr(),
2693 LN0->getPointerInfo(),
2694 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
2695 LN0->getAlignment());
2697 CombineTo(LN0, NewLoad, NewLoad.getValue(1));
2698 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2701 // Do not change the width of a volatile load.
2702 // Do not generate loads of non-round integer types since these can
2703 // be expensive (and would be wrong if the type is not byte sized).
2704 if (!LN0->isVolatile() && LoadedVT.bitsGT(ExtVT) && ExtVT.isRound() &&
2705 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, ExtVT))) {
2706 EVT PtrType = LN0->getOperand(1).getValueType();
2708 unsigned Alignment = LN0->getAlignment();
2709 SDValue NewPtr = LN0->getBasePtr();
2711 // For big endian targets, we need to add an offset to the pointer
2712 // to load the correct bytes. For little endian systems, we merely
2713 // need to read fewer bytes from the same pointer.
2714 if (TLI.isBigEndian()) {
2715 unsigned LVTStoreBytes = LoadedVT.getStoreSize();
2716 unsigned EVTStoreBytes = ExtVT.getStoreSize();
2717 unsigned PtrOff = LVTStoreBytes - EVTStoreBytes;
2718 NewPtr = DAG.getNode(ISD::ADD, LN0->getDebugLoc(), PtrType,
2719 NewPtr, DAG.getConstant(PtrOff, PtrType));
2720 Alignment = MinAlign(Alignment, PtrOff);
2723 AddToWorkList(NewPtr.getNode());
2725 EVT LoadResultTy = HasAnyExt ? LN0->getValueType(0) : VT;
2727 DAG.getExtLoad(ISD::ZEXTLOAD, LN0->getDebugLoc(), LoadResultTy,
2728 LN0->getChain(), NewPtr,
2729 LN0->getPointerInfo(),
2730 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
2733 CombineTo(LN0, Load, Load.getValue(1));
2734 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2740 if (N0.getOpcode() == ISD::ADD && N1.getOpcode() == ISD::SRL &&
2741 VT.getSizeInBits() <= 64) {
2742 if (ConstantSDNode *ADDI = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
2743 APInt ADDC = ADDI->getAPIntValue();
2744 if (!TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
2745 // Look for (and (add x, c1), (lshr y, c2)). If C1 wasn't a legal
2746 // immediate for an add, but it is legal if its top c2 bits are set,
2747 // transform the ADD so the immediate doesn't need to be materialized
2749 if (ConstantSDNode *SRLI = dyn_cast<ConstantSDNode>(N1.getOperand(1))) {
2750 APInt Mask = APInt::getHighBitsSet(VT.getSizeInBits(),
2751 SRLI->getZExtValue());
2752 if (DAG.MaskedValueIsZero(N0.getOperand(1), Mask)) {
2754 if (TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
2756 DAG.getNode(ISD::ADD, N0.getDebugLoc(), VT,
2757 N0.getOperand(0), DAG.getConstant(ADDC, VT));
2758 CombineTo(N0.getNode(), NewAdd);
2759 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2771 /// MatchBSwapHWord - Match (a >> 8) | (a << 8) as (bswap a) >> 16
2773 SDValue DAGCombiner::MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
2774 bool DemandHighBits) {
2775 if (!LegalOperations)
2778 EVT VT = N->getValueType(0);
2779 if (VT != MVT::i64 && VT != MVT::i32 && VT != MVT::i16)
2781 if (!TLI.isOperationLegal(ISD::BSWAP, VT))
2784 // Recognize (and (shl a, 8), 0xff), (and (srl a, 8), 0xff00)
2785 bool LookPassAnd0 = false;
2786 bool LookPassAnd1 = false;
2787 if (N0.getOpcode() == ISD::AND && N0.getOperand(0).getOpcode() == ISD::SRL)
2789 if (N1.getOpcode() == ISD::AND && N1.getOperand(0).getOpcode() == ISD::SHL)
2791 if (N0.getOpcode() == ISD::AND) {
2792 if (!N0.getNode()->hasOneUse())
2794 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2795 if (!N01C || N01C->getZExtValue() != 0xFF00)
2797 N0 = N0.getOperand(0);
2798 LookPassAnd0 = true;
2801 if (N1.getOpcode() == ISD::AND) {
2802 if (!N1.getNode()->hasOneUse())
2804 ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
2805 if (!N11C || N11C->getZExtValue() != 0xFF)
2807 N1 = N1.getOperand(0);
2808 LookPassAnd1 = true;
2811 if (N0.getOpcode() == ISD::SRL && N1.getOpcode() == ISD::SHL)
2813 if (N0.getOpcode() != ISD::SHL || N1.getOpcode() != ISD::SRL)
2815 if (!N0.getNode()->hasOneUse() ||
2816 !N1.getNode()->hasOneUse())
2819 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2820 ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
2823 if (N01C->getZExtValue() != 8 || N11C->getZExtValue() != 8)
2826 // Look for (shl (and a, 0xff), 8), (srl (and a, 0xff00), 8)
2827 SDValue N00 = N0->getOperand(0);
2828 if (!LookPassAnd0 && N00.getOpcode() == ISD::AND) {
2829 if (!N00.getNode()->hasOneUse())
2831 ConstantSDNode *N001C = dyn_cast<ConstantSDNode>(N00.getOperand(1));
2832 if (!N001C || N001C->getZExtValue() != 0xFF)
2834 N00 = N00.getOperand(0);
2835 LookPassAnd0 = true;
2838 SDValue N10 = N1->getOperand(0);
2839 if (!LookPassAnd1 && N10.getOpcode() == ISD::AND) {
2840 if (!N10.getNode()->hasOneUse())
2842 ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N10.getOperand(1));
2843 if (!N101C || N101C->getZExtValue() != 0xFF00)
2845 N10 = N10.getOperand(0);
2846 LookPassAnd1 = true;
2852 // Make sure everything beyond the low halfword is zero since the SRL 16
2853 // will clear the top bits.
2854 unsigned OpSizeInBits = VT.getSizeInBits();
2855 if (DemandHighBits && OpSizeInBits > 16 &&
2856 (!LookPassAnd0 || !LookPassAnd1) &&
2857 !DAG.MaskedValueIsZero(N10, APInt::getHighBitsSet(OpSizeInBits, 16)))
2860 SDValue Res = DAG.getNode(ISD::BSWAP, N->getDebugLoc(), VT, N00);
2861 if (OpSizeInBits > 16)
2862 Res = DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, Res,
2863 DAG.getConstant(OpSizeInBits-16, getShiftAmountTy(VT)));
2867 /// isBSwapHWordElement - Return true if the specified node is an element
2868 /// that makes up a 32-bit packed halfword byteswap. i.e.
2869 /// ((x&0xff)<<8)|((x&0xff00)>>8)|((x&0x00ff0000)<<8)|((x&0xff000000)>>8)
2870 static bool isBSwapHWordElement(SDValue N, SmallVector<SDNode*,4> &Parts) {
2871 if (!N.getNode()->hasOneUse())
2874 unsigned Opc = N.getOpcode();
2875 if (Opc != ISD::AND && Opc != ISD::SHL && Opc != ISD::SRL)
2878 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N.getOperand(1));
2883 switch (N1C->getZExtValue()) {
2886 case 0xFF: Num = 0; break;
2887 case 0xFF00: Num = 1; break;
2888 case 0xFF0000: Num = 2; break;
2889 case 0xFF000000: Num = 3; break;
2892 // Look for (x & 0xff) << 8 as well as ((x << 8) & 0xff00).
2893 SDValue N0 = N.getOperand(0);
2894 if (Opc == ISD::AND) {
2895 if (Num == 0 || Num == 2) {
2897 // (x >> 8) & 0xff0000
2898 if (N0.getOpcode() != ISD::SRL)
2900 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2901 if (!C || C->getZExtValue() != 8)
2904 // (x << 8) & 0xff00
2905 // (x << 8) & 0xff000000
2906 if (N0.getOpcode() != ISD::SHL)
2908 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2909 if (!C || C->getZExtValue() != 8)
2912 } else if (Opc == ISD::SHL) {
2914 // (x & 0xff0000) << 8
2915 if (Num != 0 && Num != 2)
2917 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
2918 if (!C || C->getZExtValue() != 8)
2920 } else { // Opc == ISD::SRL
2921 // (x & 0xff00) >> 8
2922 // (x & 0xff000000) >> 8
2923 if (Num != 1 && Num != 3)
2925 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
2926 if (!C || C->getZExtValue() != 8)
2933 Parts[Num] = N0.getOperand(0).getNode();
2937 /// MatchBSwapHWord - Match a 32-bit packed halfword bswap. That is
2938 /// ((x&0xff)<<8)|((x&0xff00)>>8)|((x&0x00ff0000)<<8)|((x&0xff000000)>>8)
2939 /// => (rotl (bswap x), 16)
2940 SDValue DAGCombiner::MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1) {
2941 if (!LegalOperations)
2944 EVT VT = N->getValueType(0);
2947 if (!TLI.isOperationLegal(ISD::BSWAP, VT))
2950 SmallVector<SDNode*,4> Parts(4, (SDNode*)0);
2952 // (or (or (and), (and)), (or (and), (and)))
2953 // (or (or (or (and), (and)), (and)), (and))
2954 if (N0.getOpcode() != ISD::OR)
2956 SDValue N00 = N0.getOperand(0);
2957 SDValue N01 = N0.getOperand(1);
2959 if (N1.getOpcode() == ISD::OR) {
2960 // (or (or (and), (and)), (or (and), (and)))
2961 SDValue N000 = N00.getOperand(0);
2962 if (!isBSwapHWordElement(N000, Parts))
2965 SDValue N001 = N00.getOperand(1);
2966 if (!isBSwapHWordElement(N001, Parts))
2968 SDValue N010 = N01.getOperand(0);
2969 if (!isBSwapHWordElement(N010, Parts))
2971 SDValue N011 = N01.getOperand(1);
2972 if (!isBSwapHWordElement(N011, Parts))
2975 // (or (or (or (and), (and)), (and)), (and))
2976 if (!isBSwapHWordElement(N1, Parts))
2978 if (!isBSwapHWordElement(N01, Parts))
2980 if (N00.getOpcode() != ISD::OR)
2982 SDValue N000 = N00.getOperand(0);
2983 if (!isBSwapHWordElement(N000, Parts))
2985 SDValue N001 = N00.getOperand(1);
2986 if (!isBSwapHWordElement(N001, Parts))
2990 // Make sure the parts are all coming from the same node.
2991 if (Parts[0] != Parts[1] || Parts[0] != Parts[2] || Parts[0] != Parts[3])
2994 SDValue BSwap = DAG.getNode(ISD::BSWAP, N->getDebugLoc(), VT,
2995 SDValue(Parts[0],0));
2997 // Result of the bswap should be rotated by 16. If it's not legal, than
2998 // do (x << 16) | (x >> 16).
2999 SDValue ShAmt = DAG.getConstant(16, getShiftAmountTy(VT));
3000 if (TLI.isOperationLegalOrCustom(ISD::ROTL, VT))
3001 return DAG.getNode(ISD::ROTL, N->getDebugLoc(), VT, BSwap, ShAmt);
3002 if (TLI.isOperationLegalOrCustom(ISD::ROTR, VT))
3003 return DAG.getNode(ISD::ROTR, N->getDebugLoc(), VT, BSwap, ShAmt);
3004 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT,
3005 DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, BSwap, ShAmt),
3006 DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, BSwap, ShAmt));
3009 SDValue DAGCombiner::visitOR(SDNode *N) {
3010 SDValue N0 = N->getOperand(0);
3011 SDValue N1 = N->getOperand(1);
3012 SDValue LL, LR, RL, RR, CC0, CC1;
3013 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3014 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3015 EVT VT = N1.getValueType();
3018 if (VT.isVector()) {
3019 SDValue FoldedVOp = SimplifyVBinOp(N);
3020 if (FoldedVOp.getNode()) return FoldedVOp;
3023 // fold (or x, undef) -> -1
3024 if (!LegalOperations &&
3025 (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)) {
3026 EVT EltVT = VT.isVector() ? VT.getVectorElementType() : VT;
3027 return DAG.getConstant(APInt::getAllOnesValue(EltVT.getSizeInBits()), VT);
3029 // fold (or c1, c2) -> c1|c2
3031 return DAG.FoldConstantArithmetic(ISD::OR, VT, N0C, N1C);
3032 // canonicalize constant to RHS
3034 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N1, N0);
3035 // fold (or x, 0) -> x
3036 if (N1C && N1C->isNullValue())
3038 // fold (or x, -1) -> -1
3039 if (N1C && N1C->isAllOnesValue())
3041 // fold (or x, c) -> c iff (x & ~c) == 0
3042 if (N1C && DAG.MaskedValueIsZero(N0, ~N1C->getAPIntValue()))
3045 // Recognize halfword bswaps as (bswap + rotl 16) or (bswap + shl 16)
3046 SDValue BSwap = MatchBSwapHWord(N, N0, N1);
3047 if (BSwap.getNode() != 0)
3049 BSwap = MatchBSwapHWordLow(N, N0, N1);
3050 if (BSwap.getNode() != 0)
3054 SDValue ROR = ReassociateOps(ISD::OR, N->getDebugLoc(), N0, N1);
3055 if (ROR.getNode() != 0)
3057 // Canonicalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2)
3058 // iff (c1 & c2) == 0.
3059 if (N1C && N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
3060 isa<ConstantSDNode>(N0.getOperand(1))) {
3061 ConstantSDNode *C1 = cast<ConstantSDNode>(N0.getOperand(1));
3062 if ((C1->getAPIntValue() & N1C->getAPIntValue()) != 0)
3063 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
3064 DAG.getNode(ISD::OR, N0.getDebugLoc(), VT,
3065 N0.getOperand(0), N1),
3066 DAG.FoldConstantArithmetic(ISD::OR, VT, N1C, C1));
3068 // fold (or (setcc x), (setcc y)) -> (setcc (or x, y))
3069 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
3070 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
3071 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
3073 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
3074 LL.getValueType().isInteger()) {
3075 // fold (or (setne X, 0), (setne Y, 0)) -> (setne (or X, Y), 0)
3076 // fold (or (setlt X, 0), (setlt Y, 0)) -> (setne (or X, Y), 0)
3077 if (cast<ConstantSDNode>(LR)->isNullValue() &&
3078 (Op1 == ISD::SETNE || Op1 == ISD::SETLT)) {
3079 SDValue ORNode = DAG.getNode(ISD::OR, LR.getDebugLoc(),
3080 LR.getValueType(), LL, RL);
3081 AddToWorkList(ORNode.getNode());
3082 return DAG.getSetCC(N->getDebugLoc(), VT, ORNode, LR, Op1);
3084 // fold (or (setne X, -1), (setne Y, -1)) -> (setne (and X, Y), -1)
3085 // fold (or (setgt X, -1), (setgt Y -1)) -> (setgt (and X, Y), -1)
3086 if (cast<ConstantSDNode>(LR)->isAllOnesValue() &&
3087 (Op1 == ISD::SETNE || Op1 == ISD::SETGT)) {
3088 SDValue ANDNode = DAG.getNode(ISD::AND, LR.getDebugLoc(),
3089 LR.getValueType(), LL, RL);
3090 AddToWorkList(ANDNode.getNode());
3091 return DAG.getSetCC(N->getDebugLoc(), VT, ANDNode, LR, Op1);
3094 // canonicalize equivalent to ll == rl
3095 if (LL == RR && LR == RL) {
3096 Op1 = ISD::getSetCCSwappedOperands(Op1);
3099 if (LL == RL && LR == RR) {
3100 bool isInteger = LL.getValueType().isInteger();
3101 ISD::CondCode Result = ISD::getSetCCOrOperation(Op0, Op1, isInteger);
3102 if (Result != ISD::SETCC_INVALID &&
3103 (!LegalOperations || TLI.isCondCodeLegal(Result, LL.getValueType())))
3104 return DAG.getSetCC(N->getDebugLoc(), N0.getValueType(),
3109 // Simplify: (or (op x...), (op y...)) -> (op (or x, y))
3110 if (N0.getOpcode() == N1.getOpcode()) {
3111 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
3112 if (Tmp.getNode()) return Tmp;
3115 // (or (and X, C1), (and Y, C2)) -> (and (or X, Y), C3) if possible.
3116 if (N0.getOpcode() == ISD::AND &&
3117 N1.getOpcode() == ISD::AND &&
3118 N0.getOperand(1).getOpcode() == ISD::Constant &&
3119 N1.getOperand(1).getOpcode() == ISD::Constant &&
3120 // Don't increase # computations.
3121 (N0.getNode()->hasOneUse() || N1.getNode()->hasOneUse())) {
3122 // We can only do this xform if we know that bits from X that are set in C2
3123 // but not in C1 are already zero. Likewise for Y.
3124 const APInt &LHSMask =
3125 cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
3126 const APInt &RHSMask =
3127 cast<ConstantSDNode>(N1.getOperand(1))->getAPIntValue();
3129 if (DAG.MaskedValueIsZero(N0.getOperand(0), RHSMask&~LHSMask) &&
3130 DAG.MaskedValueIsZero(N1.getOperand(0), LHSMask&~RHSMask)) {
3131 SDValue X = DAG.getNode(ISD::OR, N0.getDebugLoc(), VT,
3132 N0.getOperand(0), N1.getOperand(0));
3133 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, X,
3134 DAG.getConstant(LHSMask | RHSMask, VT));
3138 // See if this is some rotate idiom.
3139 if (SDNode *Rot = MatchRotate(N0, N1, N->getDebugLoc()))
3140 return SDValue(Rot, 0);
3142 // Simplify the operands using demanded-bits information.
3143 if (!VT.isVector() &&
3144 SimplifyDemandedBits(SDValue(N, 0)))
3145 return SDValue(N, 0);
3150 /// MatchRotateHalf - Match "(X shl/srl V1) & V2" where V2 may not be present.
3151 static bool MatchRotateHalf(SDValue Op, SDValue &Shift, SDValue &Mask) {
3152 if (Op.getOpcode() == ISD::AND) {
3153 if (isa<ConstantSDNode>(Op.getOperand(1))) {
3154 Mask = Op.getOperand(1);
3155 Op = Op.getOperand(0);
3161 if (Op.getOpcode() == ISD::SRL || Op.getOpcode() == ISD::SHL) {
3169 // MatchRotate - Handle an 'or' of two operands. If this is one of the many
3170 // idioms for rotate, and if the target supports rotation instructions, generate
3172 SDNode *DAGCombiner::MatchRotate(SDValue LHS, SDValue RHS, DebugLoc DL) {
3173 // Must be a legal type. Expanded 'n promoted things won't work with rotates.
3174 EVT VT = LHS.getValueType();
3175 if (!TLI.isTypeLegal(VT)) return 0;
3177 // The target must have at least one rotate flavor.
3178 bool HasROTL = TLI.isOperationLegalOrCustom(ISD::ROTL, VT);
3179 bool HasROTR = TLI.isOperationLegalOrCustom(ISD::ROTR, VT);
3180 if (!HasROTL && !HasROTR) return 0;
3182 // Match "(X shl/srl V1) & V2" where V2 may not be present.
3183 SDValue LHSShift; // The shift.
3184 SDValue LHSMask; // AND value if any.
3185 if (!MatchRotateHalf(LHS, LHSShift, LHSMask))
3186 return 0; // Not part of a rotate.
3188 SDValue RHSShift; // The shift.
3189 SDValue RHSMask; // AND value if any.
3190 if (!MatchRotateHalf(RHS, RHSShift, RHSMask))
3191 return 0; // Not part of a rotate.
3193 if (LHSShift.getOperand(0) != RHSShift.getOperand(0))
3194 return 0; // Not shifting the same value.
3196 if (LHSShift.getOpcode() == RHSShift.getOpcode())
3197 return 0; // Shifts must disagree.
3199 // Canonicalize shl to left side in a shl/srl pair.
3200 if (RHSShift.getOpcode() == ISD::SHL) {
3201 std::swap(LHS, RHS);
3202 std::swap(LHSShift, RHSShift);
3203 std::swap(LHSMask , RHSMask );
3206 unsigned OpSizeInBits = VT.getSizeInBits();
3207 SDValue LHSShiftArg = LHSShift.getOperand(0);
3208 SDValue LHSShiftAmt = LHSShift.getOperand(1);
3209 SDValue RHSShiftAmt = RHSShift.getOperand(1);
3211 // fold (or (shl x, C1), (srl x, C2)) -> (rotl x, C1)
3212 // fold (or (shl x, C1), (srl x, C2)) -> (rotr x, C2)
3213 if (LHSShiftAmt.getOpcode() == ISD::Constant &&
3214 RHSShiftAmt.getOpcode() == ISD::Constant) {
3215 uint64_t LShVal = cast<ConstantSDNode>(LHSShiftAmt)->getZExtValue();
3216 uint64_t RShVal = cast<ConstantSDNode>(RHSShiftAmt)->getZExtValue();
3217 if ((LShVal + RShVal) != OpSizeInBits)
3220 SDValue Rot = DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT,
3221 LHSShiftArg, HasROTL ? LHSShiftAmt : RHSShiftAmt);
3223 // If there is an AND of either shifted operand, apply it to the result.
3224 if (LHSMask.getNode() || RHSMask.getNode()) {
3225 APInt Mask = APInt::getAllOnesValue(OpSizeInBits);
3227 if (LHSMask.getNode()) {
3228 APInt RHSBits = APInt::getLowBitsSet(OpSizeInBits, LShVal);
3229 Mask &= cast<ConstantSDNode>(LHSMask)->getAPIntValue() | RHSBits;
3231 if (RHSMask.getNode()) {
3232 APInt LHSBits = APInt::getHighBitsSet(OpSizeInBits, RShVal);
3233 Mask &= cast<ConstantSDNode>(RHSMask)->getAPIntValue() | LHSBits;
3236 Rot = DAG.getNode(ISD::AND, DL, VT, Rot, DAG.getConstant(Mask, VT));
3239 return Rot.getNode();
3242 // If there is a mask here, and we have a variable shift, we can't be sure
3243 // that we're masking out the right stuff.
3244 if (LHSMask.getNode() || RHSMask.getNode())
3247 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotl x, y)
3248 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotr x, (sub 32, y))
3249 if (RHSShiftAmt.getOpcode() == ISD::SUB &&
3250 LHSShiftAmt == RHSShiftAmt.getOperand(1)) {
3251 if (ConstantSDNode *SUBC =
3252 dyn_cast<ConstantSDNode>(RHSShiftAmt.getOperand(0))) {
3253 if (SUBC->getAPIntValue() == OpSizeInBits) {
3254 return DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT, LHSShiftArg,
3255 HasROTL ? LHSShiftAmt : RHSShiftAmt).getNode();
3260 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotr x, y)
3261 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotl x, (sub 32, y))
3262 if (LHSShiftAmt.getOpcode() == ISD::SUB &&
3263 RHSShiftAmt == LHSShiftAmt.getOperand(1)) {
3264 if (ConstantSDNode *SUBC =
3265 dyn_cast<ConstantSDNode>(LHSShiftAmt.getOperand(0))) {
3266 if (SUBC->getAPIntValue() == OpSizeInBits) {
3267 return DAG.getNode(HasROTR ? ISD::ROTR : ISD::ROTL, DL, VT, LHSShiftArg,
3268 HasROTR ? RHSShiftAmt : LHSShiftAmt).getNode();
3273 // Look for sign/zext/any-extended or truncate cases:
3274 if ((LHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
3275 LHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
3276 LHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
3277 LHSShiftAmt.getOpcode() == ISD::TRUNCATE) &&
3278 (RHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
3279 RHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
3280 RHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
3281 RHSShiftAmt.getOpcode() == ISD::TRUNCATE)) {
3282 SDValue LExtOp0 = LHSShiftAmt.getOperand(0);
3283 SDValue RExtOp0 = RHSShiftAmt.getOperand(0);
3284 if (RExtOp0.getOpcode() == ISD::SUB &&
3285 RExtOp0.getOperand(1) == LExtOp0) {
3286 // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
3288 // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
3289 // (rotr x, (sub 32, y))
3290 if (ConstantSDNode *SUBC =
3291 dyn_cast<ConstantSDNode>(RExtOp0.getOperand(0))) {
3292 if (SUBC->getAPIntValue() == OpSizeInBits) {
3293 return DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT,
3295 HasROTL ? LHSShiftAmt : RHSShiftAmt).getNode();
3298 } else if (LExtOp0.getOpcode() == ISD::SUB &&
3299 RExtOp0 == LExtOp0.getOperand(1)) {
3300 // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext y))) ->
3302 // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext y))) ->
3303 // (rotl x, (sub 32, y))
3304 if (ConstantSDNode *SUBC =
3305 dyn_cast<ConstantSDNode>(LExtOp0.getOperand(0))) {
3306 if (SUBC->getAPIntValue() == OpSizeInBits) {
3307 return DAG.getNode(HasROTR ? ISD::ROTR : ISD::ROTL, DL, VT,
3309 HasROTR ? RHSShiftAmt : LHSShiftAmt).getNode();
3318 SDValue DAGCombiner::visitXOR(SDNode *N) {
3319 SDValue N0 = N->getOperand(0);
3320 SDValue N1 = N->getOperand(1);
3321 SDValue LHS, RHS, CC;
3322 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3323 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3324 EVT VT = N0.getValueType();
3327 if (VT.isVector()) {
3328 SDValue FoldedVOp = SimplifyVBinOp(N);
3329 if (FoldedVOp.getNode()) return FoldedVOp;
3332 // fold (xor undef, undef) -> 0. This is a common idiom (misuse).
3333 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
3334 return DAG.getConstant(0, VT);
3335 // fold (xor x, undef) -> undef
3336 if (N0.getOpcode() == ISD::UNDEF)
3338 if (N1.getOpcode() == ISD::UNDEF)
3340 // fold (xor c1, c2) -> c1^c2
3342 return DAG.FoldConstantArithmetic(ISD::XOR, VT, N0C, N1C);
3343 // canonicalize constant to RHS
3345 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N1, N0);
3346 // fold (xor x, 0) -> x
3347 if (N1C && N1C->isNullValue())
3350 SDValue RXOR = ReassociateOps(ISD::XOR, N->getDebugLoc(), N0, N1);
3351 if (RXOR.getNode() != 0)
3354 // fold !(x cc y) -> (x !cc y)
3355 if (N1C && N1C->getAPIntValue() == 1 && isSetCCEquivalent(N0, LHS, RHS, CC)) {
3356 bool isInt = LHS.getValueType().isInteger();
3357 ISD::CondCode NotCC = ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
3360 if (!LegalOperations || TLI.isCondCodeLegal(NotCC, LHS.getValueType())) {
3361 switch (N0.getOpcode()) {
3363 llvm_unreachable("Unhandled SetCC Equivalent!");
3365 return DAG.getSetCC(N->getDebugLoc(), VT, LHS, RHS, NotCC);
3366 case ISD::SELECT_CC:
3367 return DAG.getSelectCC(N->getDebugLoc(), LHS, RHS, N0.getOperand(2),
3368 N0.getOperand(3), NotCC);
3373 // fold (not (zext (setcc x, y))) -> (zext (not (setcc x, y)))
3374 if (N1C && N1C->getAPIntValue() == 1 && N0.getOpcode() == ISD::ZERO_EXTEND &&
3375 N0.getNode()->hasOneUse() &&
3376 isSetCCEquivalent(N0.getOperand(0), LHS, RHS, CC)){
3377 SDValue V = N0.getOperand(0);
3378 V = DAG.getNode(ISD::XOR, N0.getDebugLoc(), V.getValueType(), V,
3379 DAG.getConstant(1, V.getValueType()));
3380 AddToWorkList(V.getNode());
3381 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, V);
3384 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are setcc
3385 if (N1C && N1C->getAPIntValue() == 1 && VT == MVT::i1 &&
3386 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
3387 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
3388 if (isOneUseSetCC(RHS) || isOneUseSetCC(LHS)) {
3389 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
3390 LHS = DAG.getNode(ISD::XOR, LHS.getDebugLoc(), VT, LHS, N1); // LHS = ~LHS
3391 RHS = DAG.getNode(ISD::XOR, RHS.getDebugLoc(), VT, RHS, N1); // RHS = ~RHS
3392 AddToWorkList(LHS.getNode()); AddToWorkList(RHS.getNode());
3393 return DAG.getNode(NewOpcode, N->getDebugLoc(), VT, LHS, RHS);
3396 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are constants
3397 if (N1C && N1C->isAllOnesValue() &&
3398 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
3399 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
3400 if (isa<ConstantSDNode>(RHS) || isa<ConstantSDNode>(LHS)) {
3401 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
3402 LHS = DAG.getNode(ISD::XOR, LHS.getDebugLoc(), VT, LHS, N1); // LHS = ~LHS
3403 RHS = DAG.getNode(ISD::XOR, RHS.getDebugLoc(), VT, RHS, N1); // RHS = ~RHS
3404 AddToWorkList(LHS.getNode()); AddToWorkList(RHS.getNode());
3405 return DAG.getNode(NewOpcode, N->getDebugLoc(), VT, LHS, RHS);
3408 // fold (xor (xor x, c1), c2) -> (xor x, (xor c1, c2))
3409 if (N1C && N0.getOpcode() == ISD::XOR) {
3410 ConstantSDNode *N00C = dyn_cast<ConstantSDNode>(N0.getOperand(0));
3411 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3413 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N0.getOperand(1),
3414 DAG.getConstant(N1C->getAPIntValue() ^
3415 N00C->getAPIntValue(), VT));
3417 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N0.getOperand(0),
3418 DAG.getConstant(N1C->getAPIntValue() ^
3419 N01C->getAPIntValue(), VT));
3421 // fold (xor x, x) -> 0
3423 return tryFoldToZero(N->getDebugLoc(), TLI, VT, DAG, LegalOperations);
3425 // Simplify: xor (op x...), (op y...) -> (op (xor x, y))
3426 if (N0.getOpcode() == N1.getOpcode()) {
3427 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
3428 if (Tmp.getNode()) return Tmp;
3431 // Simplify the expression using non-local knowledge.
3432 if (!VT.isVector() &&
3433 SimplifyDemandedBits(SDValue(N, 0)))
3434 return SDValue(N, 0);
3439 /// visitShiftByConstant - Handle transforms common to the three shifts, when
3440 /// the shift amount is a constant.
3441 SDValue DAGCombiner::visitShiftByConstant(SDNode *N, unsigned Amt) {
3442 SDNode *LHS = N->getOperand(0).getNode();
3443 if (!LHS->hasOneUse()) return SDValue();
3445 // We want to pull some binops through shifts, so that we have (and (shift))
3446 // instead of (shift (and)), likewise for add, or, xor, etc. This sort of
3447 // thing happens with address calculations, so it's important to canonicalize
3449 bool HighBitSet = false; // Can we transform this if the high bit is set?
3451 switch (LHS->getOpcode()) {
3452 default: return SDValue();
3455 HighBitSet = false; // We can only transform sra if the high bit is clear.
3458 HighBitSet = true; // We can only transform sra if the high bit is set.
3461 if (N->getOpcode() != ISD::SHL)
3462 return SDValue(); // only shl(add) not sr[al](add).
3463 HighBitSet = false; // We can only transform sra if the high bit is clear.
3467 // We require the RHS of the binop to be a constant as well.
3468 ConstantSDNode *BinOpCst = dyn_cast<ConstantSDNode>(LHS->getOperand(1));
3469 if (!BinOpCst) return SDValue();
3471 // FIXME: disable this unless the input to the binop is a shift by a constant.
3472 // If it is not a shift, it pessimizes some common cases like:
3474 // void foo(int *X, int i) { X[i & 1235] = 1; }
3475 // int bar(int *X, int i) { return X[i & 255]; }
3476 SDNode *BinOpLHSVal = LHS->getOperand(0).getNode();
3477 if ((BinOpLHSVal->getOpcode() != ISD::SHL &&
3478 BinOpLHSVal->getOpcode() != ISD::SRA &&
3479 BinOpLHSVal->getOpcode() != ISD::SRL) ||
3480 !isa<ConstantSDNode>(BinOpLHSVal->getOperand(1)))
3483 EVT VT = N->getValueType(0);
3485 // If this is a signed shift right, and the high bit is modified by the
3486 // logical operation, do not perform the transformation. The highBitSet
3487 // boolean indicates the value of the high bit of the constant which would
3488 // cause it to be modified for this operation.
3489 if (N->getOpcode() == ISD::SRA) {
3490 bool BinOpRHSSignSet = BinOpCst->getAPIntValue().isNegative();
3491 if (BinOpRHSSignSet != HighBitSet)
3495 // Fold the constants, shifting the binop RHS by the shift amount.
3496 SDValue NewRHS = DAG.getNode(N->getOpcode(), LHS->getOperand(1).getDebugLoc(),
3498 LHS->getOperand(1), N->getOperand(1));
3500 // Create the new shift.
3501 SDValue NewShift = DAG.getNode(N->getOpcode(),
3502 LHS->getOperand(0).getDebugLoc(),
3503 VT, LHS->getOperand(0), N->getOperand(1));
3505 // Create the new binop.
3506 return DAG.getNode(LHS->getOpcode(), N->getDebugLoc(), VT, NewShift, NewRHS);
3509 SDValue DAGCombiner::visitSHL(SDNode *N) {
3510 SDValue N0 = N->getOperand(0);
3511 SDValue N1 = N->getOperand(1);
3512 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3513 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3514 EVT VT = N0.getValueType();
3515 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
3517 // fold (shl c1, c2) -> c1<<c2
3519 return DAG.FoldConstantArithmetic(ISD::SHL, VT, N0C, N1C);
3520 // fold (shl 0, x) -> 0
3521 if (N0C && N0C->isNullValue())
3523 // fold (shl x, c >= size(x)) -> undef
3524 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
3525 return DAG.getUNDEF(VT);
3526 // fold (shl x, 0) -> x
3527 if (N1C && N1C->isNullValue())
3529 // fold (shl undef, x) -> 0
3530 if (N0.getOpcode() == ISD::UNDEF)
3531 return DAG.getConstant(0, VT);
3532 // if (shl x, c) is known to be zero, return 0
3533 if (DAG.MaskedValueIsZero(SDValue(N, 0),
3534 APInt::getAllOnesValue(OpSizeInBits)))
3535 return DAG.getConstant(0, VT);
3536 // fold (shl x, (trunc (and y, c))) -> (shl x, (and (trunc y), (trunc c))).
3537 if (N1.getOpcode() == ISD::TRUNCATE &&
3538 N1.getOperand(0).getOpcode() == ISD::AND &&
3539 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
3540 SDValue N101 = N1.getOperand(0).getOperand(1);
3541 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
3542 EVT TruncVT = N1.getValueType();
3543 SDValue N100 = N1.getOperand(0).getOperand(0);
3544 APInt TruncC = N101C->getAPIntValue();
3545 TruncC = TruncC.trunc(TruncVT.getSizeInBits());
3546 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0,
3547 DAG.getNode(ISD::AND, N->getDebugLoc(), TruncVT,
3548 DAG.getNode(ISD::TRUNCATE,
3551 DAG.getConstant(TruncC, TruncVT)));
3555 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
3556 return SDValue(N, 0);
3558 // fold (shl (shl x, c1), c2) -> 0 or (shl x, (add c1, c2))
3559 if (N1C && N0.getOpcode() == ISD::SHL &&
3560 N0.getOperand(1).getOpcode() == ISD::Constant) {
3561 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
3562 uint64_t c2 = N1C->getZExtValue();
3563 if (c1 + c2 >= OpSizeInBits)
3564 return DAG.getConstant(0, VT);
3565 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0.getOperand(0),
3566 DAG.getConstant(c1 + c2, N1.getValueType()));
3569 // fold (shl (ext (shl x, c1)), c2) -> (ext (shl x, (add c1, c2)))
3570 // For this to be valid, the second form must not preserve any of the bits
3571 // that are shifted out by the inner shift in the first form. This means
3572 // the outer shift size must be >= the number of bits added by the ext.
3573 // As a corollary, we don't care what kind of ext it is.
3574 if (N1C && (N0.getOpcode() == ISD::ZERO_EXTEND ||
3575 N0.getOpcode() == ISD::ANY_EXTEND ||
3576 N0.getOpcode() == ISD::SIGN_EXTEND) &&
3577 N0.getOperand(0).getOpcode() == ISD::SHL &&
3578 isa<ConstantSDNode>(N0.getOperand(0)->getOperand(1))) {
3580 cast<ConstantSDNode>(N0.getOperand(0)->getOperand(1))->getZExtValue();
3581 uint64_t c2 = N1C->getZExtValue();
3582 EVT InnerShiftVT = N0.getOperand(0).getValueType();
3583 uint64_t InnerShiftSize = InnerShiftVT.getScalarType().getSizeInBits();
3584 if (c2 >= OpSizeInBits - InnerShiftSize) {
3585 if (c1 + c2 >= OpSizeInBits)
3586 return DAG.getConstant(0, VT);
3587 return DAG.getNode(ISD::SHL, N0->getDebugLoc(), VT,
3588 DAG.getNode(N0.getOpcode(), N0->getDebugLoc(), VT,
3589 N0.getOperand(0)->getOperand(0)),
3590 DAG.getConstant(c1 + c2, N1.getValueType()));
3594 // fold (shl (srl x, c1), c2) -> (and (shl x, (sub c2, c1), MASK) or
3595 // (and (srl x, (sub c1, c2), MASK)
3596 // Only fold this if the inner shift has no other uses -- if it does, folding
3597 // this will increase the total number of instructions.
3598 if (N1C && N0.getOpcode() == ISD::SRL && N0.hasOneUse() &&
3599 N0.getOperand(1).getOpcode() == ISD::Constant) {
3600 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
3601 if (c1 < VT.getSizeInBits()) {
3602 uint64_t c2 = N1C->getZExtValue();
3603 APInt Mask = APInt::getHighBitsSet(VT.getSizeInBits(),
3604 VT.getSizeInBits() - c1);
3607 Mask = Mask.shl(c2-c1);
3608 Shift = DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0.getOperand(0),
3609 DAG.getConstant(c2-c1, N1.getValueType()));
3611 Mask = Mask.lshr(c1-c2);
3612 Shift = DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0.getOperand(0),
3613 DAG.getConstant(c1-c2, N1.getValueType()));
3615 return DAG.getNode(ISD::AND, N0.getDebugLoc(), VT, Shift,
3616 DAG.getConstant(Mask, VT));
3619 // fold (shl (sra x, c1), c1) -> (and x, (shl -1, c1))
3620 if (N1C && N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1)) {
3621 SDValue HiBitsMask =
3622 DAG.getConstant(APInt::getHighBitsSet(VT.getSizeInBits(),
3623 VT.getSizeInBits() -
3624 N1C->getZExtValue()),
3626 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0.getOperand(0),
3631 SDValue NewSHL = visitShiftByConstant(N, N1C->getZExtValue());
3632 if (NewSHL.getNode())
3639 SDValue DAGCombiner::visitSRA(SDNode *N) {
3640 SDValue N0 = N->getOperand(0);
3641 SDValue N1 = N->getOperand(1);
3642 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3643 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3644 EVT VT = N0.getValueType();
3645 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
3647 // fold (sra c1, c2) -> (sra c1, c2)
3649 return DAG.FoldConstantArithmetic(ISD::SRA, VT, N0C, N1C);
3650 // fold (sra 0, x) -> 0
3651 if (N0C && N0C->isNullValue())
3653 // fold (sra -1, x) -> -1
3654 if (N0C && N0C->isAllOnesValue())
3656 // fold (sra x, (setge c, size(x))) -> undef
3657 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
3658 return DAG.getUNDEF(VT);
3659 // fold (sra x, 0) -> x
3660 if (N1C && N1C->isNullValue())
3662 // fold (sra (shl x, c1), c1) -> sext_inreg for some c1 and target supports
3664 if (N1C && N0.getOpcode() == ISD::SHL && N1 == N0.getOperand(1)) {
3665 unsigned LowBits = OpSizeInBits - (unsigned)N1C->getZExtValue();
3666 EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), LowBits);
3668 ExtVT = EVT::getVectorVT(*DAG.getContext(),
3669 ExtVT, VT.getVectorNumElements());
3670 if ((!LegalOperations ||
3671 TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, ExtVT)))
3672 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT,
3673 N0.getOperand(0), DAG.getValueType(ExtVT));
3676 // fold (sra (sra x, c1), c2) -> (sra x, (add c1, c2))
3677 if (N1C && N0.getOpcode() == ISD::SRA) {
3678 if (ConstantSDNode *C1 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
3679 unsigned Sum = N1C->getZExtValue() + C1->getZExtValue();
3680 if (Sum >= OpSizeInBits) Sum = OpSizeInBits-1;
3681 return DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, N0.getOperand(0),
3682 DAG.getConstant(Sum, N1C->getValueType(0)));
3686 // fold (sra (shl X, m), (sub result_size, n))
3687 // -> (sign_extend (trunc (shl X, (sub (sub result_size, n), m)))) for
3688 // result_size - n != m.
3689 // If truncate is free for the target sext(shl) is likely to result in better
3691 if (N0.getOpcode() == ISD::SHL) {
3692 // Get the two constanst of the shifts, CN0 = m, CN = n.
3693 const ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3695 // Determine what the truncate's result bitsize and type would be.
3697 EVT::getIntegerVT(*DAG.getContext(),
3698 OpSizeInBits - N1C->getZExtValue());
3699 // Determine the residual right-shift amount.
3700 signed ShiftAmt = N1C->getZExtValue() - N01C->getZExtValue();
3702 // If the shift is not a no-op (in which case this should be just a sign
3703 // extend already), the truncated to type is legal, sign_extend is legal
3704 // on that type, and the truncate to that type is both legal and free,
3705 // perform the transform.
3706 if ((ShiftAmt > 0) &&
3707 TLI.isOperationLegalOrCustom(ISD::SIGN_EXTEND, TruncVT) &&
3708 TLI.isOperationLegalOrCustom(ISD::TRUNCATE, VT) &&
3709 TLI.isTruncateFree(VT, TruncVT)) {
3711 SDValue Amt = DAG.getConstant(ShiftAmt,
3712 getShiftAmountTy(N0.getOperand(0).getValueType()));
3713 SDValue Shift = DAG.getNode(ISD::SRL, N0.getDebugLoc(), VT,
3714 N0.getOperand(0), Amt);
3715 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(), TruncVT,
3717 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(),
3718 N->getValueType(0), Trunc);
3723 // fold (sra x, (trunc (and y, c))) -> (sra x, (and (trunc y), (trunc c))).
3724 if (N1.getOpcode() == ISD::TRUNCATE &&
3725 N1.getOperand(0).getOpcode() == ISD::AND &&
3726 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
3727 SDValue N101 = N1.getOperand(0).getOperand(1);
3728 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
3729 EVT TruncVT = N1.getValueType();
3730 SDValue N100 = N1.getOperand(0).getOperand(0);
3731 APInt TruncC = N101C->getAPIntValue();
3732 TruncC = TruncC.trunc(TruncVT.getScalarType().getSizeInBits());
3733 return DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, N0,
3734 DAG.getNode(ISD::AND, N->getDebugLoc(),
3736 DAG.getNode(ISD::TRUNCATE,
3739 DAG.getConstant(TruncC, TruncVT)));
3743 // fold (sra (trunc (sr x, c1)), c2) -> (trunc (sra x, c1+c2))
3744 // if c1 is equal to the number of bits the trunc removes
3745 if (N0.getOpcode() == ISD::TRUNCATE &&
3746 (N0.getOperand(0).getOpcode() == ISD::SRL ||
3747 N0.getOperand(0).getOpcode() == ISD::SRA) &&
3748 N0.getOperand(0).hasOneUse() &&
3749 N0.getOperand(0).getOperand(1).hasOneUse() &&
3750 N1C && isa<ConstantSDNode>(N0.getOperand(0).getOperand(1))) {
3751 EVT LargeVT = N0.getOperand(0).getValueType();
3752 ConstantSDNode *LargeShiftAmt =
3753 cast<ConstantSDNode>(N0.getOperand(0).getOperand(1));
3755 if (LargeVT.getScalarType().getSizeInBits() - OpSizeInBits ==
3756 LargeShiftAmt->getZExtValue()) {
3758 DAG.getConstant(LargeShiftAmt->getZExtValue() + N1C->getZExtValue(),
3759 getShiftAmountTy(N0.getOperand(0).getOperand(0).getValueType()));
3760 SDValue SRA = DAG.getNode(ISD::SRA, N->getDebugLoc(), LargeVT,
3761 N0.getOperand(0).getOperand(0), Amt);
3762 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, SRA);
3766 // Simplify, based on bits shifted out of the LHS.
3767 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
3768 return SDValue(N, 0);
3771 // If the sign bit is known to be zero, switch this to a SRL.
3772 if (DAG.SignBitIsZero(N0))
3773 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0, N1);
3776 SDValue NewSRA = visitShiftByConstant(N, N1C->getZExtValue());
3777 if (NewSRA.getNode())
3784 SDValue DAGCombiner::visitSRL(SDNode *N) {
3785 SDValue N0 = N->getOperand(0);
3786 SDValue N1 = N->getOperand(1);
3787 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3788 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3789 EVT VT = N0.getValueType();
3790 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
3792 // fold (srl c1, c2) -> c1 >>u c2
3794 return DAG.FoldConstantArithmetic(ISD::SRL, VT, N0C, N1C);
3795 // fold (srl 0, x) -> 0
3796 if (N0C && N0C->isNullValue())
3798 // fold (srl x, c >= size(x)) -> undef
3799 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
3800 return DAG.getUNDEF(VT);
3801 // fold (srl x, 0) -> x
3802 if (N1C && N1C->isNullValue())
3804 // if (srl x, c) is known to be zero, return 0
3805 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
3806 APInt::getAllOnesValue(OpSizeInBits)))
3807 return DAG.getConstant(0, VT);
3809 // fold (srl (srl x, c1), c2) -> 0 or (srl x, (add c1, c2))
3810 if (N1C && N0.getOpcode() == ISD::SRL &&
3811 N0.getOperand(1).getOpcode() == ISD::Constant) {
3812 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
3813 uint64_t c2 = N1C->getZExtValue();
3814 if (c1 + c2 >= OpSizeInBits)
3815 return DAG.getConstant(0, VT);
3816 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0.getOperand(0),
3817 DAG.getConstant(c1 + c2, N1.getValueType()));
3820 // fold (srl (trunc (srl x, c1)), c2) -> 0 or (trunc (srl x, (add c1, c2)))
3821 if (N1C && N0.getOpcode() == ISD::TRUNCATE &&
3822 N0.getOperand(0).getOpcode() == ISD::SRL &&
3823 isa<ConstantSDNode>(N0.getOperand(0)->getOperand(1))) {
3825 cast<ConstantSDNode>(N0.getOperand(0)->getOperand(1))->getZExtValue();
3826 uint64_t c2 = N1C->getZExtValue();
3827 EVT InnerShiftVT = N0.getOperand(0).getValueType();
3828 EVT ShiftCountVT = N0.getOperand(0)->getOperand(1).getValueType();
3829 uint64_t InnerShiftSize = InnerShiftVT.getScalarType().getSizeInBits();
3830 // This is only valid if the OpSizeInBits + c1 = size of inner shift.
3831 if (c1 + OpSizeInBits == InnerShiftSize) {
3832 if (c1 + c2 >= InnerShiftSize)
3833 return DAG.getConstant(0, VT);
3834 return DAG.getNode(ISD::TRUNCATE, N0->getDebugLoc(), VT,
3835 DAG.getNode(ISD::SRL, N0->getDebugLoc(), InnerShiftVT,
3836 N0.getOperand(0)->getOperand(0),
3837 DAG.getConstant(c1 + c2, ShiftCountVT)));
3841 // fold (srl (shl x, c), c) -> (and x, cst2)
3842 if (N1C && N0.getOpcode() == ISD::SHL && N0.getOperand(1) == N1 &&
3843 N0.getValueSizeInBits() <= 64) {
3844 uint64_t ShAmt = N1C->getZExtValue()+64-N0.getValueSizeInBits();
3845 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0.getOperand(0),
3846 DAG.getConstant(~0ULL >> ShAmt, VT));
3850 // fold (srl (anyextend x), c) -> (anyextend (srl x, c))
3851 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
3852 // Shifting in all undef bits?
3853 EVT SmallVT = N0.getOperand(0).getValueType();
3854 if (N1C->getZExtValue() >= SmallVT.getSizeInBits())
3855 return DAG.getUNDEF(VT);
3857 if (!LegalTypes || TLI.isTypeDesirableForOp(ISD::SRL, SmallVT)) {
3858 uint64_t ShiftAmt = N1C->getZExtValue();
3859 SDValue SmallShift = DAG.getNode(ISD::SRL, N0.getDebugLoc(), SmallVT,
3861 DAG.getConstant(ShiftAmt, getShiftAmountTy(SmallVT)));
3862 AddToWorkList(SmallShift.getNode());
3863 return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, SmallShift);
3867 // fold (srl (sra X, Y), 31) -> (srl X, 31). This srl only looks at the sign
3868 // bit, which is unmodified by sra.
3869 if (N1C && N1C->getZExtValue() + 1 == VT.getSizeInBits()) {
3870 if (N0.getOpcode() == ISD::SRA)
3871 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0.getOperand(0), N1);
3874 // fold (srl (ctlz x), "5") -> x iff x has one bit set (the low bit).
3875 if (N1C && N0.getOpcode() == ISD::CTLZ &&
3876 N1C->getAPIntValue() == Log2_32(VT.getSizeInBits())) {
3877 APInt KnownZero, KnownOne;
3878 DAG.ComputeMaskedBits(N0.getOperand(0), KnownZero, KnownOne);
3880 // If any of the input bits are KnownOne, then the input couldn't be all
3881 // zeros, thus the result of the srl will always be zero.
3882 if (KnownOne.getBoolValue()) return DAG.getConstant(0, VT);
3884 // If all of the bits input the to ctlz node are known to be zero, then
3885 // the result of the ctlz is "32" and the result of the shift is one.
3886 APInt UnknownBits = ~KnownZero;
3887 if (UnknownBits == 0) return DAG.getConstant(1, VT);
3889 // Otherwise, check to see if there is exactly one bit input to the ctlz.
3890 if ((UnknownBits & (UnknownBits - 1)) == 0) {
3891 // Okay, we know that only that the single bit specified by UnknownBits
3892 // could be set on input to the CTLZ node. If this bit is set, the SRL
3893 // will return 0, if it is clear, it returns 1. Change the CTLZ/SRL pair
3894 // to an SRL/XOR pair, which is likely to simplify more.
3895 unsigned ShAmt = UnknownBits.countTrailingZeros();
3896 SDValue Op = N0.getOperand(0);
3899 Op = DAG.getNode(ISD::SRL, N0.getDebugLoc(), VT, Op,
3900 DAG.getConstant(ShAmt, getShiftAmountTy(Op.getValueType())));
3901 AddToWorkList(Op.getNode());
3904 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT,
3905 Op, DAG.getConstant(1, VT));
3909 // fold (srl x, (trunc (and y, c))) -> (srl x, (and (trunc y), (trunc c))).
3910 if (N1.getOpcode() == ISD::TRUNCATE &&
3911 N1.getOperand(0).getOpcode() == ISD::AND &&
3912 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
3913 SDValue N101 = N1.getOperand(0).getOperand(1);
3914 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
3915 EVT TruncVT = N1.getValueType();
3916 SDValue N100 = N1.getOperand(0).getOperand(0);
3917 APInt TruncC = N101C->getAPIntValue();
3918 TruncC = TruncC.trunc(TruncVT.getSizeInBits());
3919 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0,
3920 DAG.getNode(ISD::AND, N->getDebugLoc(),
3922 DAG.getNode(ISD::TRUNCATE,
3925 DAG.getConstant(TruncC, TruncVT)));
3929 // fold operands of srl based on knowledge that the low bits are not
3931 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
3932 return SDValue(N, 0);
3935 SDValue NewSRL = visitShiftByConstant(N, N1C->getZExtValue());
3936 if (NewSRL.getNode())
3940 // Attempt to convert a srl of a load into a narrower zero-extending load.
3941 SDValue NarrowLoad = ReduceLoadWidth(N);
3942 if (NarrowLoad.getNode())
3945 // Here is a common situation. We want to optimize:
3948 // %b = and i32 %a, 2
3949 // %c = srl i32 %b, 1
3950 // brcond i32 %c ...
3956 // %c = setcc eq %b, 0
3959 // However when after the source operand of SRL is optimized into AND, the SRL
3960 // itself may not be optimized further. Look for it and add the BRCOND into
3962 if (N->hasOneUse()) {
3963 SDNode *Use = *N->use_begin();
3964 if (Use->getOpcode() == ISD::BRCOND)
3966 else if (Use->getOpcode() == ISD::TRUNCATE && Use->hasOneUse()) {
3967 // Also look pass the truncate.
3968 Use = *Use->use_begin();
3969 if (Use->getOpcode() == ISD::BRCOND)
3977 SDValue DAGCombiner::visitCTLZ(SDNode *N) {
3978 SDValue N0 = N->getOperand(0);
3979 EVT VT = N->getValueType(0);
3981 // fold (ctlz c1) -> c2
3982 if (isa<ConstantSDNode>(N0))
3983 return DAG.getNode(ISD::CTLZ, N->getDebugLoc(), VT, N0);
3987 SDValue DAGCombiner::visitCTLZ_ZERO_UNDEF(SDNode *N) {
3988 SDValue N0 = N->getOperand(0);
3989 EVT VT = N->getValueType(0);
3991 // fold (ctlz_zero_undef c1) -> c2
3992 if (isa<ConstantSDNode>(N0))
3993 return DAG.getNode(ISD::CTLZ_ZERO_UNDEF, N->getDebugLoc(), VT, N0);
3997 SDValue DAGCombiner::visitCTTZ(SDNode *N) {
3998 SDValue N0 = N->getOperand(0);
3999 EVT VT = N->getValueType(0);
4001 // fold (cttz c1) -> c2
4002 if (isa<ConstantSDNode>(N0))
4003 return DAG.getNode(ISD::CTTZ, N->getDebugLoc(), VT, N0);
4007 SDValue DAGCombiner::visitCTTZ_ZERO_UNDEF(SDNode *N) {
4008 SDValue N0 = N->getOperand(0);
4009 EVT VT = N->getValueType(0);
4011 // fold (cttz_zero_undef c1) -> c2
4012 if (isa<ConstantSDNode>(N0))
4013 return DAG.getNode(ISD::CTTZ_ZERO_UNDEF, N->getDebugLoc(), VT, N0);
4017 SDValue DAGCombiner::visitCTPOP(SDNode *N) {
4018 SDValue N0 = N->getOperand(0);
4019 EVT VT = N->getValueType(0);
4021 // fold (ctpop c1) -> c2
4022 if (isa<ConstantSDNode>(N0))
4023 return DAG.getNode(ISD::CTPOP, N->getDebugLoc(), VT, N0);
4027 SDValue DAGCombiner::visitSELECT(SDNode *N) {
4028 SDValue N0 = N->getOperand(0);
4029 SDValue N1 = N->getOperand(1);
4030 SDValue N2 = N->getOperand(2);
4031 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
4032 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
4033 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2);
4034 EVT VT = N->getValueType(0);
4035 EVT VT0 = N0.getValueType();
4037 // fold (select C, X, X) -> X
4040 // fold (select true, X, Y) -> X
4041 if (N0C && !N0C->isNullValue())
4043 // fold (select false, X, Y) -> Y
4044 if (N0C && N0C->isNullValue())
4046 // fold (select C, 1, X) -> (or C, X)
4047 if (VT == MVT::i1 && N1C && N1C->getAPIntValue() == 1)
4048 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N2);
4049 // fold (select C, 0, 1) -> (xor C, 1)
4050 if (VT.isInteger() &&
4053 TLI.getBooleanContents(false) ==
4054 TargetLowering::ZeroOrOneBooleanContent)) &&
4055 N1C && N2C && N1C->isNullValue() && N2C->getAPIntValue() == 1) {
4058 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT0,
4059 N0, DAG.getConstant(1, VT0));
4060 XORNode = DAG.getNode(ISD::XOR, N0.getDebugLoc(), VT0,
4061 N0, DAG.getConstant(1, VT0));
4062 AddToWorkList(XORNode.getNode());
4064 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, XORNode);
4065 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, XORNode);
4067 // fold (select C, 0, X) -> (and (not C), X)
4068 if (VT == VT0 && VT == MVT::i1 && N1C && N1C->isNullValue()) {
4069 SDValue NOTNode = DAG.getNOT(N0.getDebugLoc(), N0, VT);
4070 AddToWorkList(NOTNode.getNode());
4071 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, NOTNode, N2);
4073 // fold (select C, X, 1) -> (or (not C), X)
4074 if (VT == VT0 && VT == MVT::i1 && N2C && N2C->getAPIntValue() == 1) {
4075 SDValue NOTNode = DAG.getNOT(N0.getDebugLoc(), N0, VT);
4076 AddToWorkList(NOTNode.getNode());
4077 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, NOTNode, N1);
4079 // fold (select C, X, 0) -> (and C, X)
4080 if (VT == MVT::i1 && N2C && N2C->isNullValue())
4081 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0, N1);
4082 // fold (select X, X, Y) -> (or X, Y)
4083 // fold (select X, 1, Y) -> (or X, Y)
4084 if (VT == MVT::i1 && (N0 == N1 || (N1C && N1C->getAPIntValue() == 1)))
4085 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N2);
4086 // fold (select X, Y, X) -> (and X, Y)
4087 // fold (select X, Y, 0) -> (and X, Y)
4088 if (VT == MVT::i1 && (N0 == N2 || (N2C && N2C->getAPIntValue() == 0)))
4089 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0, N1);
4091 // If we can fold this based on the true/false value, do so.
4092 if (SimplifySelectOps(N, N1, N2))
4093 return SDValue(N, 0); // Don't revisit N.
4095 // fold selects based on a setcc into other things, such as min/max/abs
4096 if (N0.getOpcode() == ISD::SETCC) {
4098 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
4099 // having to say they don't support SELECT_CC on every type the DAG knows
4100 // about, since there is no way to mark an opcode illegal at all value types
4101 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other) &&
4102 TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT))
4103 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT,
4104 N0.getOperand(0), N0.getOperand(1),
4105 N1, N2, N0.getOperand(2));
4106 return SimplifySelect(N->getDebugLoc(), N0, N1, N2);
4112 SDValue DAGCombiner::visitSELECT_CC(SDNode *N) {
4113 SDValue N0 = N->getOperand(0);
4114 SDValue N1 = N->getOperand(1);
4115 SDValue N2 = N->getOperand(2);
4116 SDValue N3 = N->getOperand(3);
4117 SDValue N4 = N->getOperand(4);
4118 ISD::CondCode CC = cast<CondCodeSDNode>(N4)->get();
4120 // fold select_cc lhs, rhs, x, x, cc -> x
4124 // Determine if the condition we're dealing with is constant
4125 SDValue SCC = SimplifySetCC(TLI.getSetCCResultType(N0.getValueType()),
4126 N0, N1, CC, N->getDebugLoc(), false);
4127 if (SCC.getNode()) AddToWorkList(SCC.getNode());
4129 if (ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.getNode())) {
4130 if (!SCCC->isNullValue())
4131 return N2; // cond always true -> true val
4133 return N3; // cond always false -> false val
4136 // Fold to a simpler select_cc
4137 if (SCC.getNode() && SCC.getOpcode() == ISD::SETCC)
4138 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), N2.getValueType(),
4139 SCC.getOperand(0), SCC.getOperand(1), N2, N3,
4142 // If we can fold this based on the true/false value, do so.
4143 if (SimplifySelectOps(N, N2, N3))
4144 return SDValue(N, 0); // Don't revisit N.
4146 // fold select_cc into other things, such as min/max/abs
4147 return SimplifySelectCC(N->getDebugLoc(), N0, N1, N2, N3, CC);
4150 SDValue DAGCombiner::visitSETCC(SDNode *N) {
4151 return SimplifySetCC(N->getValueType(0), N->getOperand(0), N->getOperand(1),
4152 cast<CondCodeSDNode>(N->getOperand(2))->get(),
4156 // ExtendUsesToFormExtLoad - Trying to extend uses of a load to enable this:
4157 // "fold ({s|z|a}ext (load x)) -> ({s|z|a}ext (truncate ({s|z|a}extload x)))"
4158 // transformation. Returns true if extension are possible and the above
4159 // mentioned transformation is profitable.
4160 static bool ExtendUsesToFormExtLoad(SDNode *N, SDValue N0,
4162 SmallVector<SDNode*, 4> &ExtendNodes,
4163 const TargetLowering &TLI) {
4164 bool HasCopyToRegUses = false;
4165 bool isTruncFree = TLI.isTruncateFree(N->getValueType(0), N0.getValueType());
4166 for (SDNode::use_iterator UI = N0.getNode()->use_begin(),
4167 UE = N0.getNode()->use_end();
4172 if (UI.getUse().getResNo() != N0.getResNo())
4174 // FIXME: Only extend SETCC N, N and SETCC N, c for now.
4175 if (ExtOpc != ISD::ANY_EXTEND && User->getOpcode() == ISD::SETCC) {
4176 ISD::CondCode CC = cast<CondCodeSDNode>(User->getOperand(2))->get();
4177 if (ExtOpc == ISD::ZERO_EXTEND && ISD::isSignedIntSetCC(CC))
4178 // Sign bits will be lost after a zext.
4181 for (unsigned i = 0; i != 2; ++i) {
4182 SDValue UseOp = User->getOperand(i);
4185 if (!isa<ConstantSDNode>(UseOp))
4190 ExtendNodes.push_back(User);
4193 // If truncates aren't free and there are users we can't
4194 // extend, it isn't worthwhile.
4197 // Remember if this value is live-out.
4198 if (User->getOpcode() == ISD::CopyToReg)
4199 HasCopyToRegUses = true;
4202 if (HasCopyToRegUses) {
4203 bool BothLiveOut = false;
4204 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
4206 SDUse &Use = UI.getUse();
4207 if (Use.getResNo() == 0 && Use.getUser()->getOpcode() == ISD::CopyToReg) {
4213 // Both unextended and extended values are live out. There had better be
4214 // a good reason for the transformation.
4215 return ExtendNodes.size();
4220 void DAGCombiner::ExtendSetCCUses(SmallVector<SDNode*, 4> SetCCs,
4221 SDValue Trunc, SDValue ExtLoad, DebugLoc DL,
4222 ISD::NodeType ExtType) {
4223 // Extend SetCC uses if necessary.
4224 for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
4225 SDNode *SetCC = SetCCs[i];
4226 SmallVector<SDValue, 4> Ops;
4228 for (unsigned j = 0; j != 2; ++j) {
4229 SDValue SOp = SetCC->getOperand(j);
4231 Ops.push_back(ExtLoad);
4233 Ops.push_back(DAG.getNode(ExtType, DL, ExtLoad->getValueType(0), SOp));
4236 Ops.push_back(SetCC->getOperand(2));
4237 CombineTo(SetCC, DAG.getNode(ISD::SETCC, DL, SetCC->getValueType(0),
4238 &Ops[0], Ops.size()));
4242 SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
4243 SDValue N0 = N->getOperand(0);
4244 EVT VT = N->getValueType(0);
4246 // fold (sext c1) -> c1
4247 if (isa<ConstantSDNode>(N0))
4248 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, N0);
4250 // fold (sext (sext x)) -> (sext x)
4251 // fold (sext (aext x)) -> (sext x)
4252 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
4253 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT,
4256 if (N0.getOpcode() == ISD::TRUNCATE) {
4257 // fold (sext (truncate (load x))) -> (sext (smaller load x))
4258 // fold (sext (truncate (srl (load x), c))) -> (sext (smaller load (x+c/n)))
4259 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4260 if (NarrowLoad.getNode()) {
4261 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4262 if (NarrowLoad.getNode() != N0.getNode()) {
4263 CombineTo(N0.getNode(), NarrowLoad);
4264 // CombineTo deleted the truncate, if needed, but not what's under it.
4267 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4270 // See if the value being truncated is already sign extended. If so, just
4271 // eliminate the trunc/sext pair.
4272 SDValue Op = N0.getOperand(0);
4273 unsigned OpBits = Op.getValueType().getScalarType().getSizeInBits();
4274 unsigned MidBits = N0.getValueType().getScalarType().getSizeInBits();
4275 unsigned DestBits = VT.getScalarType().getSizeInBits();
4276 unsigned NumSignBits = DAG.ComputeNumSignBits(Op);
4278 if (OpBits == DestBits) {
4279 // Op is i32, Mid is i8, and Dest is i32. If Op has more than 24 sign
4280 // bits, it is already ready.
4281 if (NumSignBits > DestBits-MidBits)
4283 } else if (OpBits < DestBits) {
4284 // Op is i32, Mid is i8, and Dest is i64. If Op has more than 24 sign
4285 // bits, just sext from i32.
4286 if (NumSignBits > OpBits-MidBits)
4287 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, Op);
4289 // Op is i64, Mid is i8, and Dest is i32. If Op has more than 56 sign
4290 // bits, just truncate to i32.
4291 if (NumSignBits > OpBits-MidBits)
4292 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, Op);
4295 // fold (sext (truncate x)) -> (sextinreg x).
4296 if (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG,
4297 N0.getValueType())) {
4298 if (OpBits < DestBits)
4299 Op = DAG.getNode(ISD::ANY_EXTEND, N0.getDebugLoc(), VT, Op);
4300 else if (OpBits > DestBits)
4301 Op = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(), VT, Op);
4302 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT, Op,
4303 DAG.getValueType(N0.getValueType()));
4307 // fold (sext (load x)) -> (sext (truncate (sextload x)))
4308 // None of the supported targets knows how to perform load and sign extend
4309 // on vectors in one instruction. We only perform this transformation on
4311 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
4312 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
4313 TLI.isLoadExtLegal(ISD::SEXTLOAD, N0.getValueType()))) {
4314 bool DoXform = true;
4315 SmallVector<SDNode*, 4> SetCCs;
4316 if (!N0.hasOneUse())
4317 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::SIGN_EXTEND, SetCCs, TLI);
4319 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4320 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, N->getDebugLoc(), VT,
4322 LN0->getBasePtr(), LN0->getPointerInfo(),
4324 LN0->isVolatile(), LN0->isNonTemporal(),
4325 LN0->getAlignment());
4326 CombineTo(N, ExtLoad);
4327 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
4328 N0.getValueType(), ExtLoad);
4329 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
4330 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
4332 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4336 // fold (sext (sextload x)) -> (sext (truncate (sextload x)))
4337 // fold (sext ( extload x)) -> (sext (truncate (sextload x)))
4338 if ((ISD::isSEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
4339 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
4340 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4341 EVT MemVT = LN0->getMemoryVT();
4342 if ((!LegalOperations && !LN0->isVolatile()) ||
4343 TLI.isLoadExtLegal(ISD::SEXTLOAD, MemVT)) {
4344 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, N->getDebugLoc(), VT,
4346 LN0->getBasePtr(), LN0->getPointerInfo(),
4348 LN0->isVolatile(), LN0->isNonTemporal(),
4349 LN0->getAlignment());
4350 CombineTo(N, ExtLoad);
4351 CombineTo(N0.getNode(),
4352 DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
4353 N0.getValueType(), ExtLoad),
4354 ExtLoad.getValue(1));
4355 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4359 // fold (sext (and/or/xor (load x), cst)) ->
4360 // (and/or/xor (sextload x), (sext cst))
4361 if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
4362 N0.getOpcode() == ISD::XOR) &&
4363 isa<LoadSDNode>(N0.getOperand(0)) &&
4364 N0.getOperand(1).getOpcode() == ISD::Constant &&
4365 TLI.isLoadExtLegal(ISD::SEXTLOAD, N0.getValueType()) &&
4366 (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
4367 LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
4368 if (LN0->getExtensionType() != ISD::ZEXTLOAD) {
4369 bool DoXform = true;
4370 SmallVector<SDNode*, 4> SetCCs;
4371 if (!N0.hasOneUse())
4372 DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::SIGN_EXTEND,
4375 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, LN0->getDebugLoc(), VT,
4376 LN0->getChain(), LN0->getBasePtr(),
4377 LN0->getPointerInfo(),
4380 LN0->isNonTemporal(),
4381 LN0->getAlignment());
4382 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4383 Mask = Mask.sext(VT.getSizeInBits());
4384 SDValue And = DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT,
4385 ExtLoad, DAG.getConstant(Mask, VT));
4386 SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
4387 N0.getOperand(0).getDebugLoc(),
4388 N0.getOperand(0).getValueType(), ExtLoad);
4390 CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
4391 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
4393 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4398 if (N0.getOpcode() == ISD::SETCC) {
4399 // sext(setcc) -> sext_in_reg(vsetcc) for vectors.
4400 // Only do this before legalize for now.
4401 if (VT.isVector() && !LegalOperations) {
4402 EVT N0VT = N0.getOperand(0).getValueType();
4403 // On some architectures (such as SSE/NEON/etc) the SETCC result type is
4404 // of the same size as the compared operands. Only optimize sext(setcc())
4405 // if this is the case.
4406 EVT SVT = TLI.getSetCCResultType(N0VT);
4408 // We know that the # elements of the results is the same as the
4409 // # elements of the compare (and the # elements of the compare result
4410 // for that matter). Check to see that they are the same size. If so,
4411 // we know that the element size of the sext'd result matches the
4412 // element size of the compare operands.
4413 if (VT.getSizeInBits() == SVT.getSizeInBits())
4414 return DAG.getSetCC(N->getDebugLoc(), VT, N0.getOperand(0),
4416 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4417 // If the desired elements are smaller or larger than the source
4418 // elements we can use a matching integer vector type and then
4419 // truncate/sign extend
4420 EVT MatchingElementType =
4421 EVT::getIntegerVT(*DAG.getContext(),
4422 N0VT.getScalarType().getSizeInBits());
4423 EVT MatchingVectorType =
4424 EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
4425 N0VT.getVectorNumElements());
4427 if (SVT == MatchingVectorType) {
4428 SDValue VsetCC = DAG.getSetCC(N->getDebugLoc(), MatchingVectorType,
4429 N0.getOperand(0), N0.getOperand(1),
4430 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4431 return DAG.getSExtOrTrunc(VsetCC, N->getDebugLoc(), VT);
4435 // sext(setcc x, y, cc) -> (select_cc x, y, -1, 0, cc)
4436 unsigned ElementWidth = VT.getScalarType().getSizeInBits();
4438 DAG.getConstant(APInt::getAllOnesValue(ElementWidth), VT);
4440 SimplifySelectCC(N->getDebugLoc(), N0.getOperand(0), N0.getOperand(1),
4441 NegOne, DAG.getConstant(0, VT),
4442 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
4443 if (SCC.getNode()) return SCC;
4444 if (!LegalOperations ||
4445 TLI.isOperationLegal(ISD::SETCC, TLI.getSetCCResultType(VT)))
4446 return DAG.getNode(ISD::SELECT, N->getDebugLoc(), VT,
4447 DAG.getSetCC(N->getDebugLoc(),
4448 TLI.getSetCCResultType(VT),
4449 N0.getOperand(0), N0.getOperand(1),
4450 cast<CondCodeSDNode>(N0.getOperand(2))->get()),
4451 NegOne, DAG.getConstant(0, VT));
4454 // fold (sext x) -> (zext x) if the sign bit is known zero.
4455 if ((!LegalOperations || TLI.isOperationLegal(ISD::ZERO_EXTEND, VT)) &&
4456 DAG.SignBitIsZero(N0))
4457 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, N0);
4462 // isTruncateOf - If N is a truncate of some other value, return true, record
4463 // the value being truncated in Op and which of Op's bits are zero in KnownZero.
4464 // This function computes KnownZero to avoid a duplicated call to
4465 // ComputeMaskedBits in the caller.
4466 static bool isTruncateOf(SelectionDAG &DAG, SDValue N, SDValue &Op,
4469 if (N->getOpcode() == ISD::TRUNCATE) {
4470 Op = N->getOperand(0);
4471 DAG.ComputeMaskedBits(Op, KnownZero, KnownOne);
4475 if (N->getOpcode() != ISD::SETCC || N->getValueType(0) != MVT::i1 ||
4476 cast<CondCodeSDNode>(N->getOperand(2))->get() != ISD::SETNE)
4479 SDValue Op0 = N->getOperand(0);
4480 SDValue Op1 = N->getOperand(1);
4481 assert(Op0.getValueType() == Op1.getValueType());
4483 ConstantSDNode *COp0 = dyn_cast<ConstantSDNode>(Op0);
4484 ConstantSDNode *COp1 = dyn_cast<ConstantSDNode>(Op1);
4485 if (COp0 && COp0->isNullValue())
4487 else if (COp1 && COp1->isNullValue())
4492 DAG.ComputeMaskedBits(Op, KnownZero, KnownOne);
4494 if (!(KnownZero | APInt(Op.getValueSizeInBits(), 1)).isAllOnesValue())
4500 SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) {
4501 SDValue N0 = N->getOperand(0);
4502 EVT VT = N->getValueType(0);
4504 // fold (zext c1) -> c1
4505 if (isa<ConstantSDNode>(N0))
4506 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, N0);
4507 // fold (zext (zext x)) -> (zext x)
4508 // fold (zext (aext x)) -> (zext x)
4509 if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
4510 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT,
4513 // fold (zext (truncate x)) -> (zext x) or
4514 // (zext (truncate x)) -> (truncate x)
4515 // This is valid when the truncated bits of x are already zero.
4516 // FIXME: We should extend this to work for vectors too.
4519 if (!VT.isVector() && isTruncateOf(DAG, N0, Op, KnownZero)) {
4520 APInt TruncatedBits =
4521 (Op.getValueSizeInBits() == N0.getValueSizeInBits()) ?
4522 APInt(Op.getValueSizeInBits(), 0) :
4523 APInt::getBitsSet(Op.getValueSizeInBits(),
4524 N0.getValueSizeInBits(),
4525 std::min(Op.getValueSizeInBits(),
4526 VT.getSizeInBits()));
4527 if (TruncatedBits == (KnownZero & TruncatedBits)) {
4528 if (VT.bitsGT(Op.getValueType()))
4529 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, Op);
4530 if (VT.bitsLT(Op.getValueType()))
4531 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, Op);
4537 // fold (zext (truncate (load x))) -> (zext (smaller load x))
4538 // fold (zext (truncate (srl (load x), c))) -> (zext (small load (x+c/n)))
4539 if (N0.getOpcode() == ISD::TRUNCATE) {
4540 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4541 if (NarrowLoad.getNode()) {
4542 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4543 if (NarrowLoad.getNode() != N0.getNode()) {
4544 CombineTo(N0.getNode(), NarrowLoad);
4545 // CombineTo deleted the truncate, if needed, but not what's under it.
4548 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4552 // fold (zext (truncate x)) -> (and x, mask)
4553 if (N0.getOpcode() == ISD::TRUNCATE &&
4554 (!LegalOperations || TLI.isOperationLegal(ISD::AND, VT))) {
4556 // fold (zext (truncate (load x))) -> (zext (smaller load x))
4557 // fold (zext (truncate (srl (load x), c))) -> (zext (smaller load (x+c/n)))
4558 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4559 if (NarrowLoad.getNode()) {
4560 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4561 if (NarrowLoad.getNode() != N0.getNode()) {
4562 CombineTo(N0.getNode(), NarrowLoad);
4563 // CombineTo deleted the truncate, if needed, but not what's under it.
4566 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4569 SDValue Op = N0.getOperand(0);
4570 if (Op.getValueType().bitsLT(VT)) {
4571 Op = DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, Op);
4572 AddToWorkList(Op.getNode());
4573 } else if (Op.getValueType().bitsGT(VT)) {
4574 Op = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, Op);
4575 AddToWorkList(Op.getNode());
4577 return DAG.getZeroExtendInReg(Op, N->getDebugLoc(),
4578 N0.getValueType().getScalarType());
4581 // Fold (zext (and (trunc x), cst)) -> (and x, cst),
4582 // if either of the casts is not free.
4583 if (N0.getOpcode() == ISD::AND &&
4584 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
4585 N0.getOperand(1).getOpcode() == ISD::Constant &&
4586 (!TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
4587 N0.getValueType()) ||
4588 !TLI.isZExtFree(N0.getValueType(), VT))) {
4589 SDValue X = N0.getOperand(0).getOperand(0);
4590 if (X.getValueType().bitsLT(VT)) {
4591 X = DAG.getNode(ISD::ANY_EXTEND, X.getDebugLoc(), VT, X);
4592 } else if (X.getValueType().bitsGT(VT)) {
4593 X = DAG.getNode(ISD::TRUNCATE, X.getDebugLoc(), VT, X);
4595 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4596 Mask = Mask.zext(VT.getSizeInBits());
4597 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
4598 X, DAG.getConstant(Mask, VT));
4601 // fold (zext (load x)) -> (zext (truncate (zextload x)))
4602 // None of the supported targets knows how to perform load and vector_zext
4603 // on vectors in one instruction. We only perform this transformation on
4605 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
4606 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
4607 TLI.isLoadExtLegal(ISD::ZEXTLOAD, N0.getValueType()))) {
4608 bool DoXform = true;
4609 SmallVector<SDNode*, 4> SetCCs;
4610 if (!N0.hasOneUse())
4611 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ZERO_EXTEND, SetCCs, TLI);
4613 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4614 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, N->getDebugLoc(), VT,
4616 LN0->getBasePtr(), LN0->getPointerInfo(),
4618 LN0->isVolatile(), LN0->isNonTemporal(),
4619 LN0->getAlignment());
4620 CombineTo(N, ExtLoad);
4621 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
4622 N0.getValueType(), ExtLoad);
4623 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
4625 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
4627 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4631 // fold (zext (and/or/xor (load x), cst)) ->
4632 // (and/or/xor (zextload x), (zext cst))
4633 if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
4634 N0.getOpcode() == ISD::XOR) &&
4635 isa<LoadSDNode>(N0.getOperand(0)) &&
4636 N0.getOperand(1).getOpcode() == ISD::Constant &&
4637 TLI.isLoadExtLegal(ISD::ZEXTLOAD, N0.getValueType()) &&
4638 (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
4639 LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
4640 if (LN0->getExtensionType() != ISD::SEXTLOAD) {
4641 bool DoXform = true;
4642 SmallVector<SDNode*, 4> SetCCs;
4643 if (!N0.hasOneUse())
4644 DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::ZERO_EXTEND,
4647 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, LN0->getDebugLoc(), VT,
4648 LN0->getChain(), LN0->getBasePtr(),
4649 LN0->getPointerInfo(),
4652 LN0->isNonTemporal(),
4653 LN0->getAlignment());
4654 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4655 Mask = Mask.zext(VT.getSizeInBits());
4656 SDValue And = DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT,
4657 ExtLoad, DAG.getConstant(Mask, VT));
4658 SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
4659 N0.getOperand(0).getDebugLoc(),
4660 N0.getOperand(0).getValueType(), ExtLoad);
4662 CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
4663 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
4665 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4670 // fold (zext (zextload x)) -> (zext (truncate (zextload x)))
4671 // fold (zext ( extload x)) -> (zext (truncate (zextload x)))
4672 if ((ISD::isZEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
4673 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
4674 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4675 EVT MemVT = LN0->getMemoryVT();
4676 if ((!LegalOperations && !LN0->isVolatile()) ||
4677 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT)) {
4678 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, N->getDebugLoc(), VT,
4680 LN0->getBasePtr(), LN0->getPointerInfo(),
4682 LN0->isVolatile(), LN0->isNonTemporal(),
4683 LN0->getAlignment());
4684 CombineTo(N, ExtLoad);
4685 CombineTo(N0.getNode(),
4686 DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(), N0.getValueType(),
4688 ExtLoad.getValue(1));
4689 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4693 if (N0.getOpcode() == ISD::SETCC) {
4694 if (!LegalOperations && VT.isVector()) {
4695 // zext(setcc) -> (and (vsetcc), (1, 1, ...) for vectors.
4696 // Only do this before legalize for now.
4697 EVT N0VT = N0.getOperand(0).getValueType();
4698 EVT EltVT = VT.getVectorElementType();
4699 SmallVector<SDValue,8> OneOps(VT.getVectorNumElements(),
4700 DAG.getConstant(1, EltVT));
4701 if (VT.getSizeInBits() == N0VT.getSizeInBits())
4702 // We know that the # elements of the results is the same as the
4703 // # elements of the compare (and the # elements of the compare result
4704 // for that matter). Check to see that they are the same size. If so,
4705 // we know that the element size of the sext'd result matches the
4706 // element size of the compare operands.
4707 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
4708 DAG.getSetCC(N->getDebugLoc(), VT, N0.getOperand(0),
4710 cast<CondCodeSDNode>(N0.getOperand(2))->get()),
4711 DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(), VT,
4712 &OneOps[0], OneOps.size()));
4714 // If the desired elements are smaller or larger than the source
4715 // elements we can use a matching integer vector type and then
4716 // truncate/sign extend
4717 EVT MatchingElementType =
4718 EVT::getIntegerVT(*DAG.getContext(),
4719 N0VT.getScalarType().getSizeInBits());
4720 EVT MatchingVectorType =
4721 EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
4722 N0VT.getVectorNumElements());
4724 DAG.getSetCC(N->getDebugLoc(), MatchingVectorType, N0.getOperand(0),
4726 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4727 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
4728 DAG.getSExtOrTrunc(VsetCC, N->getDebugLoc(), VT),
4729 DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(), VT,
4730 &OneOps[0], OneOps.size()));
4733 // zext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
4735 SimplifySelectCC(N->getDebugLoc(), N0.getOperand(0), N0.getOperand(1),
4736 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
4737 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
4738 if (SCC.getNode()) return SCC;
4741 // (zext (shl (zext x), cst)) -> (shl (zext x), cst)
4742 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL) &&
4743 isa<ConstantSDNode>(N0.getOperand(1)) &&
4744 N0.getOperand(0).getOpcode() == ISD::ZERO_EXTEND &&
4746 SDValue ShAmt = N0.getOperand(1);
4747 unsigned ShAmtVal = cast<ConstantSDNode>(ShAmt)->getZExtValue();
4748 if (N0.getOpcode() == ISD::SHL) {
4749 SDValue InnerZExt = N0.getOperand(0);
4750 // If the original shl may be shifting out bits, do not perform this
4752 unsigned KnownZeroBits = InnerZExt.getValueType().getSizeInBits() -
4753 InnerZExt.getOperand(0).getValueType().getSizeInBits();
4754 if (ShAmtVal > KnownZeroBits)
4758 DebugLoc DL = N->getDebugLoc();
4760 // Ensure that the shift amount is wide enough for the shifted value.
4761 if (VT.getSizeInBits() >= 256)
4762 ShAmt = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, ShAmt);
4764 return DAG.getNode(N0.getOpcode(), DL, VT,
4765 DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0)),
4772 SDValue DAGCombiner::visitANY_EXTEND(SDNode *N) {
4773 SDValue N0 = N->getOperand(0);
4774 EVT VT = N->getValueType(0);
4776 // fold (aext c1) -> c1
4777 if (isa<ConstantSDNode>(N0))
4778 return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, N0);
4779 // fold (aext (aext x)) -> (aext x)
4780 // fold (aext (zext x)) -> (zext x)
4781 // fold (aext (sext x)) -> (sext x)
4782 if (N0.getOpcode() == ISD::ANY_EXTEND ||
4783 N0.getOpcode() == ISD::ZERO_EXTEND ||
4784 N0.getOpcode() == ISD::SIGN_EXTEND)
4785 return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT, N0.getOperand(0));
4787 // fold (aext (truncate (load x))) -> (aext (smaller load x))
4788 // fold (aext (truncate (srl (load x), c))) -> (aext (small load (x+c/n)))
4789 if (N0.getOpcode() == ISD::TRUNCATE) {
4790 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4791 if (NarrowLoad.getNode()) {
4792 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4793 if (NarrowLoad.getNode() != N0.getNode()) {
4794 CombineTo(N0.getNode(), NarrowLoad);
4795 // CombineTo deleted the truncate, if needed, but not what's under it.
4798 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4802 // fold (aext (truncate x))
4803 if (N0.getOpcode() == ISD::TRUNCATE) {
4804 SDValue TruncOp = N0.getOperand(0);
4805 if (TruncOp.getValueType() == VT)
4806 return TruncOp; // x iff x size == zext size.
4807 if (TruncOp.getValueType().bitsGT(VT))
4808 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, TruncOp);
4809 return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, TruncOp);
4812 // Fold (aext (and (trunc x), cst)) -> (and x, cst)
4813 // if the trunc is not free.
4814 if (N0.getOpcode() == ISD::AND &&
4815 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
4816 N0.getOperand(1).getOpcode() == ISD::Constant &&
4817 !TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
4818 N0.getValueType())) {
4819 SDValue X = N0.getOperand(0).getOperand(0);
4820 if (X.getValueType().bitsLT(VT)) {
4821 X = DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, X);
4822 } else if (X.getValueType().bitsGT(VT)) {
4823 X = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, X);
4825 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4826 Mask = Mask.zext(VT.getSizeInBits());
4827 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
4828 X, DAG.getConstant(Mask, VT));
4831 // fold (aext (load x)) -> (aext (truncate (extload x)))
4832 // None of the supported targets knows how to perform load and any_ext
4833 // on vectors in one instruction. We only perform this transformation on
4835 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
4836 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
4837 TLI.isLoadExtLegal(ISD::EXTLOAD, N0.getValueType()))) {
4838 bool DoXform = true;
4839 SmallVector<SDNode*, 4> SetCCs;
4840 if (!N0.hasOneUse())
4841 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ANY_EXTEND, SetCCs, TLI);
4843 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4844 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, N->getDebugLoc(), VT,
4846 LN0->getBasePtr(), LN0->getPointerInfo(),
4848 LN0->isVolatile(), LN0->isNonTemporal(),
4849 LN0->getAlignment());
4850 CombineTo(N, ExtLoad);
4851 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
4852 N0.getValueType(), ExtLoad);
4853 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
4854 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
4856 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4860 // fold (aext (zextload x)) -> (aext (truncate (zextload x)))
4861 // fold (aext (sextload x)) -> (aext (truncate (sextload x)))
4862 // fold (aext ( extload x)) -> (aext (truncate (extload x)))
4863 if (N0.getOpcode() == ISD::LOAD &&
4864 !ISD::isNON_EXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
4866 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4867 EVT MemVT = LN0->getMemoryVT();
4868 SDValue ExtLoad = DAG.getExtLoad(LN0->getExtensionType(), N->getDebugLoc(),
4869 VT, LN0->getChain(), LN0->getBasePtr(),
4870 LN0->getPointerInfo(), MemVT,
4871 LN0->isVolatile(), LN0->isNonTemporal(),
4872 LN0->getAlignment());
4873 CombineTo(N, ExtLoad);
4874 CombineTo(N0.getNode(),
4875 DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
4876 N0.getValueType(), ExtLoad),
4877 ExtLoad.getValue(1));
4878 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4881 if (N0.getOpcode() == ISD::SETCC) {
4882 // aext(setcc) -> sext_in_reg(vsetcc) for vectors.
4883 // Only do this before legalize for now.
4884 if (VT.isVector() && !LegalOperations) {
4885 EVT N0VT = N0.getOperand(0).getValueType();
4886 // We know that the # elements of the results is the same as the
4887 // # elements of the compare (and the # elements of the compare result
4888 // for that matter). Check to see that they are the same size. If so,
4889 // we know that the element size of the sext'd result matches the
4890 // element size of the compare operands.
4891 if (VT.getSizeInBits() == N0VT.getSizeInBits())
4892 return DAG.getSetCC(N->getDebugLoc(), VT, N0.getOperand(0),
4894 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4895 // If the desired elements are smaller or larger than the source
4896 // elements we can use a matching integer vector type and then
4897 // truncate/sign extend
4899 EVT MatchingElementType =
4900 EVT::getIntegerVT(*DAG.getContext(),
4901 N0VT.getScalarType().getSizeInBits());
4902 EVT MatchingVectorType =
4903 EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
4904 N0VT.getVectorNumElements());
4906 DAG.getSetCC(N->getDebugLoc(), MatchingVectorType, N0.getOperand(0),
4908 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4909 return DAG.getSExtOrTrunc(VsetCC, N->getDebugLoc(), VT);
4913 // aext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
4915 SimplifySelectCC(N->getDebugLoc(), N0.getOperand(0), N0.getOperand(1),
4916 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
4917 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
4925 /// GetDemandedBits - See if the specified operand can be simplified with the
4926 /// knowledge that only the bits specified by Mask are used. If so, return the
4927 /// simpler operand, otherwise return a null SDValue.
4928 SDValue DAGCombiner::GetDemandedBits(SDValue V, const APInt &Mask) {
4929 switch (V.getOpcode()) {
4931 case ISD::Constant: {
4932 const ConstantSDNode *CV = cast<ConstantSDNode>(V.getNode());
4933 assert(CV != 0 && "Const value should be ConstSDNode.");
4934 const APInt &CVal = CV->getAPIntValue();
4935 APInt NewVal = CVal & Mask;
4936 if (NewVal != CVal) {
4937 return DAG.getConstant(NewVal, V.getValueType());
4943 // If the LHS or RHS don't contribute bits to the or, drop them.
4944 if (DAG.MaskedValueIsZero(V.getOperand(0), Mask))
4945 return V.getOperand(1);
4946 if (DAG.MaskedValueIsZero(V.getOperand(1), Mask))
4947 return V.getOperand(0);
4950 // Only look at single-use SRLs.
4951 if (!V.getNode()->hasOneUse())
4953 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(V.getOperand(1))) {
4954 // See if we can recursively simplify the LHS.
4955 unsigned Amt = RHSC->getZExtValue();
4957 // Watch out for shift count overflow though.
4958 if (Amt >= Mask.getBitWidth()) break;
4959 APInt NewMask = Mask << Amt;
4960 SDValue SimplifyLHS = GetDemandedBits(V.getOperand(0), NewMask);
4961 if (SimplifyLHS.getNode())
4962 return DAG.getNode(ISD::SRL, V.getDebugLoc(), V.getValueType(),
4963 SimplifyLHS, V.getOperand(1));
4969 /// ReduceLoadWidth - If the result of a wider load is shifted to right of N
4970 /// bits and then truncated to a narrower type and where N is a multiple
4971 /// of number of bits of the narrower type, transform it to a narrower load
4972 /// from address + N / num of bits of new type. If the result is to be
4973 /// extended, also fold the extension to form a extending load.
4974 SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) {
4975 unsigned Opc = N->getOpcode();
4977 ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
4978 SDValue N0 = N->getOperand(0);
4979 EVT VT = N->getValueType(0);
4982 // This transformation isn't valid for vector loads.
4986 // Special case: SIGN_EXTEND_INREG is basically truncating to ExtVT then
4988 if (Opc == ISD::SIGN_EXTEND_INREG) {
4989 ExtType = ISD::SEXTLOAD;
4990 ExtVT = cast<VTSDNode>(N->getOperand(1))->getVT();
4991 } else if (Opc == ISD::SRL) {
4992 // Another special-case: SRL is basically zero-extending a narrower value.
4993 ExtType = ISD::ZEXTLOAD;
4995 ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1));
4996 if (!N01) return SDValue();
4997 ExtVT = EVT::getIntegerVT(*DAG.getContext(),
4998 VT.getSizeInBits() - N01->getZExtValue());
5000 if (LegalOperations && !TLI.isLoadExtLegal(ExtType, ExtVT))
5003 unsigned EVTBits = ExtVT.getSizeInBits();
5005 // Do not generate loads of non-round integer types since these can
5006 // be expensive (and would be wrong if the type is not byte sized).
5007 if (!ExtVT.isRound())
5011 if (N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
5012 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
5013 ShAmt = N01->getZExtValue();
5014 // Is the shift amount a multiple of size of VT?
5015 if ((ShAmt & (EVTBits-1)) == 0) {
5016 N0 = N0.getOperand(0);
5017 // Is the load width a multiple of size of VT?
5018 if ((N0.getValueType().getSizeInBits() & (EVTBits-1)) != 0)
5022 // At this point, we must have a load or else we can't do the transform.
5023 if (!isa<LoadSDNode>(N0)) return SDValue();
5025 // If the shift amount is larger than the input type then we're not
5026 // accessing any of the loaded bytes. If the load was a zextload/extload
5027 // then the result of the shift+trunc is zero/undef (handled elsewhere).
5028 // If the load was a sextload then the result is a splat of the sign bit
5029 // of the extended byte. This is not worth optimizing for.
5030 if (ShAmt >= cast<LoadSDNode>(N0)->getMemoryVT().getSizeInBits())
5035 // If the load is shifted left (and the result isn't shifted back right),
5036 // we can fold the truncate through the shift.
5037 unsigned ShLeftAmt = 0;
5038 if (ShAmt == 0 && N0.getOpcode() == ISD::SHL && N0.hasOneUse() &&
5039 ExtVT == VT && TLI.isNarrowingProfitable(N0.getValueType(), VT)) {
5040 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
5041 ShLeftAmt = N01->getZExtValue();
5042 N0 = N0.getOperand(0);
5046 // If we haven't found a load, we can't narrow it. Don't transform one with
5047 // multiple uses, this would require adding a new load.
5048 if (!isa<LoadSDNode>(N0) || !N0.hasOneUse() ||
5049 // Don't change the width of a volatile load.
5050 cast<LoadSDNode>(N0)->isVolatile())
5053 // Verify that we are actually reducing a load width here.
5054 if (cast<LoadSDNode>(N0)->getMemoryVT().getSizeInBits() < EVTBits)
5057 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5058 EVT PtrType = N0.getOperand(1).getValueType();
5060 if (PtrType == MVT::Untyped || PtrType.isExtended())
5061 // It's not possible to generate a constant of extended or untyped type.
5064 // For big endian targets, we need to adjust the offset to the pointer to
5065 // load the correct bytes.
5066 if (TLI.isBigEndian()) {
5067 unsigned LVTStoreBits = LN0->getMemoryVT().getStoreSizeInBits();
5068 unsigned EVTStoreBits = ExtVT.getStoreSizeInBits();
5069 ShAmt = LVTStoreBits - EVTStoreBits - ShAmt;
5072 uint64_t PtrOff = ShAmt / 8;
5073 unsigned NewAlign = MinAlign(LN0->getAlignment(), PtrOff);
5074 SDValue NewPtr = DAG.getNode(ISD::ADD, LN0->getDebugLoc(),
5075 PtrType, LN0->getBasePtr(),
5076 DAG.getConstant(PtrOff, PtrType));
5077 AddToWorkList(NewPtr.getNode());
5080 if (ExtType == ISD::NON_EXTLOAD)
5081 Load = DAG.getLoad(VT, N0.getDebugLoc(), LN0->getChain(), NewPtr,
5082 LN0->getPointerInfo().getWithOffset(PtrOff),
5083 LN0->isVolatile(), LN0->isNonTemporal(),
5084 LN0->isInvariant(), NewAlign);
5086 Load = DAG.getExtLoad(ExtType, N0.getDebugLoc(), VT, LN0->getChain(),NewPtr,
5087 LN0->getPointerInfo().getWithOffset(PtrOff),
5088 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
5091 // Replace the old load's chain with the new load's chain.
5092 WorkListRemover DeadNodes(*this);
5093 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));
5095 // Shift the result left, if we've swallowed a left shift.
5096 SDValue Result = Load;
5097 if (ShLeftAmt != 0) {
5098 EVT ShImmTy = getShiftAmountTy(Result.getValueType());
5099 if (!isUIntN(ShImmTy.getSizeInBits(), ShLeftAmt))
5101 Result = DAG.getNode(ISD::SHL, N0.getDebugLoc(), VT,
5102 Result, DAG.getConstant(ShLeftAmt, ShImmTy));
5105 // Return the new loaded value.
5109 SDValue DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
5110 SDValue N0 = N->getOperand(0);
5111 SDValue N1 = N->getOperand(1);
5112 EVT VT = N->getValueType(0);
5113 EVT EVT = cast<VTSDNode>(N1)->getVT();
5114 unsigned VTBits = VT.getScalarType().getSizeInBits();
5115 unsigned EVTBits = EVT.getScalarType().getSizeInBits();
5117 // fold (sext_in_reg c1) -> c1
5118 if (isa<ConstantSDNode>(N0) || N0.getOpcode() == ISD::UNDEF)
5119 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT, N0, N1);
5121 // If the input is already sign extended, just drop the extension.
5122 if (DAG.ComputeNumSignBits(N0) >= VTBits-EVTBits+1)
5125 // fold (sext_in_reg (sext_in_reg x, VT2), VT1) -> (sext_in_reg x, minVT) pt2
5126 if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
5127 EVT.bitsLT(cast<VTSDNode>(N0.getOperand(1))->getVT())) {
5128 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT,
5129 N0.getOperand(0), N1);
5132 // fold (sext_in_reg (sext x)) -> (sext x)
5133 // fold (sext_in_reg (aext x)) -> (sext x)
5134 // if x is small enough.
5135 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND) {
5136 SDValue N00 = N0.getOperand(0);
5137 if (N00.getValueType().getScalarType().getSizeInBits() <= EVTBits &&
5138 (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND, VT)))
5139 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, N00, N1);
5142 // fold (sext_in_reg x) -> (zext_in_reg x) if the sign bit is known zero.
5143 if (DAG.MaskedValueIsZero(N0, APInt::getBitsSet(VTBits, EVTBits-1, EVTBits)))
5144 return DAG.getZeroExtendInReg(N0, N->getDebugLoc(), EVT);
5146 // fold operands of sext_in_reg based on knowledge that the top bits are not
5148 if (SimplifyDemandedBits(SDValue(N, 0)))
5149 return SDValue(N, 0);
5151 // fold (sext_in_reg (load x)) -> (smaller sextload x)
5152 // fold (sext_in_reg (srl (load x), c)) -> (smaller sextload (x+c/evtbits))
5153 SDValue NarrowLoad = ReduceLoadWidth(N);
5154 if (NarrowLoad.getNode())
5157 // fold (sext_in_reg (srl X, 24), i8) -> (sra X, 24)
5158 // fold (sext_in_reg (srl X, 23), i8) -> (sra X, 23) iff possible.
5159 // We already fold "(sext_in_reg (srl X, 25), i8) -> srl X, 25" above.
5160 if (N0.getOpcode() == ISD::SRL) {
5161 if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
5162 if (ShAmt->getZExtValue()+EVTBits <= VTBits) {
5163 // We can turn this into an SRA iff the input to the SRL is already sign
5165 unsigned InSignBits = DAG.ComputeNumSignBits(N0.getOperand(0));
5166 if (VTBits-(ShAmt->getZExtValue()+EVTBits) < InSignBits)
5167 return DAG.getNode(ISD::SRA, N->getDebugLoc(), VT,
5168 N0.getOperand(0), N0.getOperand(1));
5172 // fold (sext_inreg (extload x)) -> (sextload x)
5173 if (ISD::isEXTLoad(N0.getNode()) &&
5174 ISD::isUNINDEXEDLoad(N0.getNode()) &&
5175 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
5176 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
5177 TLI.isLoadExtLegal(ISD::SEXTLOAD, EVT))) {
5178 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5179 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, N->getDebugLoc(), VT,
5181 LN0->getBasePtr(), LN0->getPointerInfo(),
5183 LN0->isVolatile(), LN0->isNonTemporal(),
5184 LN0->getAlignment());
5185 CombineTo(N, ExtLoad);
5186 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
5187 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5189 // fold (sext_inreg (zextload x)) -> (sextload x) iff load has one use
5190 if (ISD::isZEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
5192 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
5193 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
5194 TLI.isLoadExtLegal(ISD::SEXTLOAD, EVT))) {
5195 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5196 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, N->getDebugLoc(), VT,
5198 LN0->getBasePtr(), LN0->getPointerInfo(),
5200 LN0->isVolatile(), LN0->isNonTemporal(),
5201 LN0->getAlignment());
5202 CombineTo(N, ExtLoad);
5203 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
5204 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5207 // Form (sext_inreg (bswap >> 16)) or (sext_inreg (rotl (bswap) 16))
5208 if (EVTBits <= 16 && N0.getOpcode() == ISD::OR) {
5209 SDValue BSwap = MatchBSwapHWordLow(N0.getNode(), N0.getOperand(0),
5210 N0.getOperand(1), false);
5211 if (BSwap.getNode() != 0)
5212 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT,
5219 SDValue DAGCombiner::visitTRUNCATE(SDNode *N) {
5220 SDValue N0 = N->getOperand(0);
5221 EVT VT = N->getValueType(0);
5222 bool isLE = TLI.isLittleEndian();
5225 if (N0.getValueType() == N->getValueType(0))
5227 // fold (truncate c1) -> c1
5228 if (isa<ConstantSDNode>(N0))
5229 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, N0);
5230 // fold (truncate (truncate x)) -> (truncate x)
5231 if (N0.getOpcode() == ISD::TRUNCATE)
5232 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, N0.getOperand(0));
5233 // fold (truncate (ext x)) -> (ext x) or (truncate x) or x
5234 if (N0.getOpcode() == ISD::ZERO_EXTEND ||
5235 N0.getOpcode() == ISD::SIGN_EXTEND ||
5236 N0.getOpcode() == ISD::ANY_EXTEND) {
5237 if (N0.getOperand(0).getValueType().bitsLT(VT))
5238 // if the source is smaller than the dest, we still need an extend
5239 return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT,
5241 if (N0.getOperand(0).getValueType().bitsGT(VT))
5242 // if the source is larger than the dest, than we just need the truncate
5243 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, N0.getOperand(0));
5244 // if the source and dest are the same type, we can drop both the extend
5245 // and the truncate.
5246 return N0.getOperand(0);
5249 // Fold extract-and-trunc into a narrow extract. For example:
5250 // i64 x = EXTRACT_VECTOR_ELT(v2i64 val, i32 1)
5251 // i32 y = TRUNCATE(i64 x)
5253 // v16i8 b = BITCAST (v2i64 val)
5254 // i8 x = EXTRACT_VECTOR_ELT(v16i8 b, i32 8)
5256 // Note: We only run this optimization after type legalization (which often
5257 // creates this pattern) and before operation legalization after which
5258 // we need to be more careful about the vector instructions that we generate.
5259 if (N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
5260 LegalTypes && !LegalOperations && N0->hasOneUse()) {
5262 EVT VecTy = N0.getOperand(0).getValueType();
5263 EVT ExTy = N0.getValueType();
5264 EVT TrTy = N->getValueType(0);
5266 unsigned NumElem = VecTy.getVectorNumElements();
5267 unsigned SizeRatio = ExTy.getSizeInBits()/TrTy.getSizeInBits();
5269 EVT NVT = EVT::getVectorVT(*DAG.getContext(), TrTy, SizeRatio * NumElem);
5270 assert(NVT.getSizeInBits() == VecTy.getSizeInBits() && "Invalid Size");
5272 SDValue EltNo = N0->getOperand(1);
5273 if (isa<ConstantSDNode>(EltNo) && isTypeLegal(NVT)) {
5274 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
5275 EVT IndexTy = N0->getOperand(1).getValueType();
5276 int Index = isLE ? (Elt*SizeRatio) : (Elt*SizeRatio + (SizeRatio-1));
5278 SDValue V = DAG.getNode(ISD::BITCAST, N->getDebugLoc(),
5279 NVT, N0.getOperand(0));
5281 return DAG.getNode(ISD::EXTRACT_VECTOR_ELT,
5282 N->getDebugLoc(), TrTy, V,
5283 DAG.getConstant(Index, IndexTy));
5287 // See if we can simplify the input to this truncate through knowledge that
5288 // only the low bits are being used.
5289 // For example "trunc (or (shl x, 8), y)" // -> trunc y
5290 // Currently we only perform this optimization on scalars because vectors
5291 // may have different active low bits.
5292 if (!VT.isVector()) {
5294 GetDemandedBits(N0, APInt::getLowBitsSet(N0.getValueSizeInBits(),
5295 VT.getSizeInBits()));
5296 if (Shorter.getNode())
5297 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, Shorter);
5299 // fold (truncate (load x)) -> (smaller load x)
5300 // fold (truncate (srl (load x), c)) -> (smaller load (x+c/evtbits))
5301 if (!LegalTypes || TLI.isTypeDesirableForOp(N0.getOpcode(), VT)) {
5302 SDValue Reduced = ReduceLoadWidth(N);
5303 if (Reduced.getNode())
5307 // Simplify the operands using demanded-bits information.
5308 if (!VT.isVector() &&
5309 SimplifyDemandedBits(SDValue(N, 0)))
5310 return SDValue(N, 0);
5315 static SDNode *getBuildPairElt(SDNode *N, unsigned i) {
5316 SDValue Elt = N->getOperand(i);
5317 if (Elt.getOpcode() != ISD::MERGE_VALUES)
5318 return Elt.getNode();
5319 return Elt.getOperand(Elt.getResNo()).getNode();
5322 /// CombineConsecutiveLoads - build_pair (load, load) -> load
5323 /// if load locations are consecutive.
5324 SDValue DAGCombiner::CombineConsecutiveLoads(SDNode *N, EVT VT) {
5325 assert(N->getOpcode() == ISD::BUILD_PAIR);
5327 LoadSDNode *LD1 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 0));
5328 LoadSDNode *LD2 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 1));
5329 if (!LD1 || !LD2 || !ISD::isNON_EXTLoad(LD1) || !LD1->hasOneUse() ||
5330 LD1->getPointerInfo().getAddrSpace() !=
5331 LD2->getPointerInfo().getAddrSpace())
5333 EVT LD1VT = LD1->getValueType(0);
5335 if (ISD::isNON_EXTLoad(LD2) &&
5337 // If both are volatile this would reduce the number of volatile loads.
5338 // If one is volatile it might be ok, but play conservative and bail out.
5339 !LD1->isVolatile() &&
5340 !LD2->isVolatile() &&
5341 DAG.isConsecutiveLoad(LD2, LD1, LD1VT.getSizeInBits()/8, 1)) {
5342 unsigned Align = LD1->getAlignment();
5343 unsigned NewAlign = TLI.getTargetData()->
5344 getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
5346 if (NewAlign <= Align &&
5347 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT)))
5348 return DAG.getLoad(VT, N->getDebugLoc(), LD1->getChain(),
5349 LD1->getBasePtr(), LD1->getPointerInfo(),
5350 false, false, false, Align);
5356 SDValue DAGCombiner::visitBITCAST(SDNode *N) {
5357 SDValue N0 = N->getOperand(0);
5358 EVT VT = N->getValueType(0);
5360 // If the input is a BUILD_VECTOR with all constant elements, fold this now.
5361 // Only do this before legalize, since afterward the target may be depending
5362 // on the bitconvert.
5363 // First check to see if this is all constant.
5365 N0.getOpcode() == ISD::BUILD_VECTOR && N0.getNode()->hasOneUse() &&
5367 bool isSimple = true;
5368 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i)
5369 if (N0.getOperand(i).getOpcode() != ISD::UNDEF &&
5370 N0.getOperand(i).getOpcode() != ISD::Constant &&
5371 N0.getOperand(i).getOpcode() != ISD::ConstantFP) {
5376 EVT DestEltVT = N->getValueType(0).getVectorElementType();
5377 assert(!DestEltVT.isVector() &&
5378 "Element type of vector ValueType must not be vector!");
5380 return ConstantFoldBITCASTofBUILD_VECTOR(N0.getNode(), DestEltVT);
5383 // If the input is a constant, let getNode fold it.
5384 if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
5385 SDValue Res = DAG.getNode(ISD::BITCAST, N->getDebugLoc(), VT, N0);
5386 if (Res.getNode() != N) {
5387 if (!LegalOperations ||
5388 TLI.isOperationLegal(Res.getNode()->getOpcode(), VT))
5391 // Folding it resulted in an illegal node, and it's too late to
5392 // do that. Clean up the old node and forego the transformation.
5393 // Ideally this won't happen very often, because instcombine
5394 // and the earlier dagcombine runs (where illegal nodes are
5395 // permitted) should have folded most of them already.
5396 DAG.DeleteNode(Res.getNode());
5400 // (conv (conv x, t1), t2) -> (conv x, t2)
5401 if (N0.getOpcode() == ISD::BITCAST)
5402 return DAG.getNode(ISD::BITCAST, N->getDebugLoc(), VT,
5405 // fold (conv (load x)) -> (load (conv*)x)
5406 // If the resultant load doesn't need a higher alignment than the original!
5407 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
5408 // Do not change the width of a volatile load.
5409 !cast<LoadSDNode>(N0)->isVolatile() &&
5410 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT))) {
5411 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5412 unsigned Align = TLI.getTargetData()->
5413 getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
5414 unsigned OrigAlign = LN0->getAlignment();
5416 if (Align <= OrigAlign) {
5417 SDValue Load = DAG.getLoad(VT, N->getDebugLoc(), LN0->getChain(),
5418 LN0->getBasePtr(), LN0->getPointerInfo(),
5419 LN0->isVolatile(), LN0->isNonTemporal(),
5420 LN0->isInvariant(), OrigAlign);
5422 CombineTo(N0.getNode(),
5423 DAG.getNode(ISD::BITCAST, N0.getDebugLoc(),
5424 N0.getValueType(), Load),
5430 // fold (bitconvert (fneg x)) -> (xor (bitconvert x), signbit)
5431 // fold (bitconvert (fabs x)) -> (and (bitconvert x), (not signbit))
5432 // This often reduces constant pool loads.
5433 if (((N0.getOpcode() == ISD::FNEG && !TLI.isFNegFree(VT)) ||
5434 (N0.getOpcode() == ISD::FABS && !TLI.isFAbsFree(VT))) &&
5435 N0.getNode()->hasOneUse() && VT.isInteger() &&
5436 !VT.isVector() && !N0.getValueType().isVector()) {
5437 SDValue NewConv = DAG.getNode(ISD::BITCAST, N0.getDebugLoc(), VT,
5439 AddToWorkList(NewConv.getNode());
5441 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
5442 if (N0.getOpcode() == ISD::FNEG)
5443 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT,
5444 NewConv, DAG.getConstant(SignBit, VT));
5445 assert(N0.getOpcode() == ISD::FABS);
5446 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
5447 NewConv, DAG.getConstant(~SignBit, VT));
5450 // fold (bitconvert (fcopysign cst, x)) ->
5451 // (or (and (bitconvert x), sign), (and cst, (not sign)))
5452 // Note that we don't handle (copysign x, cst) because this can always be
5453 // folded to an fneg or fabs.
5454 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse() &&
5455 isa<ConstantFPSDNode>(N0.getOperand(0)) &&
5456 VT.isInteger() && !VT.isVector()) {
5457 unsigned OrigXWidth = N0.getOperand(1).getValueType().getSizeInBits();
5458 EVT IntXVT = EVT::getIntegerVT(*DAG.getContext(), OrigXWidth);
5459 if (isTypeLegal(IntXVT)) {
5460 SDValue X = DAG.getNode(ISD::BITCAST, N0.getDebugLoc(),
5461 IntXVT, N0.getOperand(1));
5462 AddToWorkList(X.getNode());
5464 // If X has a different width than the result/lhs, sext it or truncate it.
5465 unsigned VTWidth = VT.getSizeInBits();
5466 if (OrigXWidth < VTWidth) {
5467 X = DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, X);
5468 AddToWorkList(X.getNode());
5469 } else if (OrigXWidth > VTWidth) {
5470 // To get the sign bit in the right place, we have to shift it right
5471 // before truncating.
5472 X = DAG.getNode(ISD::SRL, X.getDebugLoc(),
5473 X.getValueType(), X,
5474 DAG.getConstant(OrigXWidth-VTWidth, X.getValueType()));
5475 AddToWorkList(X.getNode());
5476 X = DAG.getNode(ISD::TRUNCATE, X.getDebugLoc(), VT, X);
5477 AddToWorkList(X.getNode());
5480 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
5481 X = DAG.getNode(ISD::AND, X.getDebugLoc(), VT,
5482 X, DAG.getConstant(SignBit, VT));
5483 AddToWorkList(X.getNode());
5485 SDValue Cst = DAG.getNode(ISD::BITCAST, N0.getDebugLoc(),
5486 VT, N0.getOperand(0));
5487 Cst = DAG.getNode(ISD::AND, Cst.getDebugLoc(), VT,
5488 Cst, DAG.getConstant(~SignBit, VT));
5489 AddToWorkList(Cst.getNode());
5491 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, X, Cst);
5495 // bitconvert(build_pair(ld, ld)) -> ld iff load locations are consecutive.
5496 if (N0.getOpcode() == ISD::BUILD_PAIR) {
5497 SDValue CombineLD = CombineConsecutiveLoads(N0.getNode(), VT);
5498 if (CombineLD.getNode())
5505 SDValue DAGCombiner::visitBUILD_PAIR(SDNode *N) {
5506 EVT VT = N->getValueType(0);
5507 return CombineConsecutiveLoads(N, VT);
5510 /// ConstantFoldBITCASTofBUILD_VECTOR - We know that BV is a build_vector
5511 /// node with Constant, ConstantFP or Undef operands. DstEltVT indicates the
5512 /// destination element value type.
5513 SDValue DAGCombiner::
5514 ConstantFoldBITCASTofBUILD_VECTOR(SDNode *BV, EVT DstEltVT) {
5515 EVT SrcEltVT = BV->getValueType(0).getVectorElementType();
5517 // If this is already the right type, we're done.
5518 if (SrcEltVT == DstEltVT) return SDValue(BV, 0);
5520 unsigned SrcBitSize = SrcEltVT.getSizeInBits();
5521 unsigned DstBitSize = DstEltVT.getSizeInBits();
5523 // If this is a conversion of N elements of one type to N elements of another
5524 // type, convert each element. This handles FP<->INT cases.
5525 if (SrcBitSize == DstBitSize) {
5526 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
5527 BV->getValueType(0).getVectorNumElements());
5529 // Due to the FP element handling below calling this routine recursively,
5530 // we can end up with a scalar-to-vector node here.
5531 if (BV->getOpcode() == ISD::SCALAR_TO_VECTOR)
5532 return DAG.getNode(ISD::SCALAR_TO_VECTOR, BV->getDebugLoc(), VT,
5533 DAG.getNode(ISD::BITCAST, BV->getDebugLoc(),
5534 DstEltVT, BV->getOperand(0)));
5536 SmallVector<SDValue, 8> Ops;
5537 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
5538 SDValue Op = BV->getOperand(i);
5539 // If the vector element type is not legal, the BUILD_VECTOR operands
5540 // are promoted and implicitly truncated. Make that explicit here.
5541 if (Op.getValueType() != SrcEltVT)
5542 Op = DAG.getNode(ISD::TRUNCATE, BV->getDebugLoc(), SrcEltVT, Op);
5543 Ops.push_back(DAG.getNode(ISD::BITCAST, BV->getDebugLoc(),
5545 AddToWorkList(Ops.back().getNode());
5547 return DAG.getNode(ISD::BUILD_VECTOR, BV->getDebugLoc(), VT,
5548 &Ops[0], Ops.size());
5551 // Otherwise, we're growing or shrinking the elements. To avoid having to
5552 // handle annoying details of growing/shrinking FP values, we convert them to
5554 if (SrcEltVT.isFloatingPoint()) {
5555 // Convert the input float vector to a int vector where the elements are the
5557 assert((SrcEltVT == MVT::f32 || SrcEltVT == MVT::f64) && "Unknown FP VT!");
5558 EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), SrcEltVT.getSizeInBits());
5559 BV = ConstantFoldBITCASTofBUILD_VECTOR(BV, IntVT).getNode();
5563 // Now we know the input is an integer vector. If the output is a FP type,
5564 // convert to integer first, then to FP of the right size.
5565 if (DstEltVT.isFloatingPoint()) {
5566 assert((DstEltVT == MVT::f32 || DstEltVT == MVT::f64) && "Unknown FP VT!");
5567 EVT TmpVT = EVT::getIntegerVT(*DAG.getContext(), DstEltVT.getSizeInBits());
5568 SDNode *Tmp = ConstantFoldBITCASTofBUILD_VECTOR(BV, TmpVT).getNode();
5570 // Next, convert to FP elements of the same size.
5571 return ConstantFoldBITCASTofBUILD_VECTOR(Tmp, DstEltVT);
5574 // Okay, we know the src/dst types are both integers of differing types.
5575 // Handling growing first.
5576 assert(SrcEltVT.isInteger() && DstEltVT.isInteger());
5577 if (SrcBitSize < DstBitSize) {
5578 unsigned NumInputsPerOutput = DstBitSize/SrcBitSize;
5580 SmallVector<SDValue, 8> Ops;
5581 for (unsigned i = 0, e = BV->getNumOperands(); i != e;
5582 i += NumInputsPerOutput) {
5583 bool isLE = TLI.isLittleEndian();
5584 APInt NewBits = APInt(DstBitSize, 0);
5585 bool EltIsUndef = true;
5586 for (unsigned j = 0; j != NumInputsPerOutput; ++j) {
5587 // Shift the previously computed bits over.
5588 NewBits <<= SrcBitSize;
5589 SDValue Op = BV->getOperand(i+ (isLE ? (NumInputsPerOutput-j-1) : j));
5590 if (Op.getOpcode() == ISD::UNDEF) continue;
5593 NewBits |= cast<ConstantSDNode>(Op)->getAPIntValue().
5594 zextOrTrunc(SrcBitSize).zext(DstBitSize);
5598 Ops.push_back(DAG.getUNDEF(DstEltVT));
5600 Ops.push_back(DAG.getConstant(NewBits, DstEltVT));
5603 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT, Ops.size());
5604 return DAG.getNode(ISD::BUILD_VECTOR, BV->getDebugLoc(), VT,
5605 &Ops[0], Ops.size());
5608 // Finally, this must be the case where we are shrinking elements: each input
5609 // turns into multiple outputs.
5610 bool isS2V = ISD::isScalarToVector(BV);
5611 unsigned NumOutputsPerInput = SrcBitSize/DstBitSize;
5612 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
5613 NumOutputsPerInput*BV->getNumOperands());
5614 SmallVector<SDValue, 8> Ops;
5616 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
5617 if (BV->getOperand(i).getOpcode() == ISD::UNDEF) {
5618 for (unsigned j = 0; j != NumOutputsPerInput; ++j)
5619 Ops.push_back(DAG.getUNDEF(DstEltVT));
5623 APInt OpVal = cast<ConstantSDNode>(BV->getOperand(i))->
5624 getAPIntValue().zextOrTrunc(SrcBitSize);
5626 for (unsigned j = 0; j != NumOutputsPerInput; ++j) {
5627 APInt ThisVal = OpVal.trunc(DstBitSize);
5628 Ops.push_back(DAG.getConstant(ThisVal, DstEltVT));
5629 if (isS2V && i == 0 && j == 0 && ThisVal.zext(SrcBitSize) == OpVal)
5630 // Simply turn this into a SCALAR_TO_VECTOR of the new type.
5631 return DAG.getNode(ISD::SCALAR_TO_VECTOR, BV->getDebugLoc(), VT,
5633 OpVal = OpVal.lshr(DstBitSize);
5636 // For big endian targets, swap the order of the pieces of each element.
5637 if (TLI.isBigEndian())
5638 std::reverse(Ops.end()-NumOutputsPerInput, Ops.end());
5641 return DAG.getNode(ISD::BUILD_VECTOR, BV->getDebugLoc(), VT,
5642 &Ops[0], Ops.size());
5645 SDValue DAGCombiner::visitFADD(SDNode *N) {
5646 SDValue N0 = N->getOperand(0);
5647 SDValue N1 = N->getOperand(1);
5648 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
5649 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
5650 EVT VT = N->getValueType(0);
5653 if (VT.isVector()) {
5654 SDValue FoldedVOp = SimplifyVBinOp(N);
5655 if (FoldedVOp.getNode()) return FoldedVOp;
5658 // fold (fadd c1, c2) -> c1 + c2
5659 if (N0CFP && N1CFP && VT != MVT::ppcf128)
5660 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0, N1);
5661 // canonicalize constant to RHS
5662 if (N0CFP && !N1CFP)
5663 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N1, N0);
5664 // fold (fadd A, 0) -> A
5665 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
5666 N1CFP->getValueAPF().isZero())
5668 // fold (fadd A, (fneg B)) -> (fsub A, B)
5669 if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
5670 isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options) == 2)
5671 return DAG.getNode(ISD::FSUB, N->getDebugLoc(), VT, N0,
5672 GetNegatedExpression(N1, DAG, LegalOperations));
5673 // fold (fadd (fneg A), B) -> (fsub B, A)
5674 if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
5675 isNegatibleForFree(N0, LegalOperations, TLI, &DAG.getTarget().Options) == 2)
5676 return DAG.getNode(ISD::FSUB, N->getDebugLoc(), VT, N1,
5677 GetNegatedExpression(N0, DAG, LegalOperations));
5679 // If allowed, fold (fadd (fadd x, c1), c2) -> (fadd x, (fadd c1, c2))
5680 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
5681 N0.getOpcode() == ISD::FADD && N0.getNode()->hasOneUse() &&
5682 isa<ConstantFPSDNode>(N0.getOperand(1)))
5683 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0.getOperand(0),
5684 DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5685 N0.getOperand(1), N1));
5687 // In unsafe math mode, we can fold chains of FADD's of the same value
5688 // into multiplications. This transform is not safe in general because
5689 // we are reducing the number of rounding steps.
5690 if (DAG.getTarget().Options.UnsafeFPMath &&
5691 TLI.isOperationLegalOrCustom(ISD::FMUL, VT) &&
5693 if (N0.getOpcode() == ISD::FMUL) {
5694 ConstantFPSDNode *CFP00 = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
5695 ConstantFPSDNode *CFP01 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
5697 // (fadd (fmul c, x), x) -> (fmul c+1, x)
5698 if (CFP00 && !CFP01 && N0.getOperand(1) == N1) {
5699 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5701 DAG.getConstantFP(1.0, VT));
5702 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5706 // (fadd (fmul x, c), x) -> (fmul c+1, x)
5707 if (CFP01 && !CFP00 && N0.getOperand(0) == N1) {
5708 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5710 DAG.getConstantFP(1.0, VT));
5711 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5715 // (fadd (fadd x, x), x) -> (fmul 3.0, x)
5716 if (!CFP00 && !CFP01 && N0.getOperand(0) == N0.getOperand(1) &&
5717 N0.getOperand(0) == N1) {
5718 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5719 N1, DAG.getConstantFP(3.0, VT));
5722 // (fadd (fmul c, x), (fadd x, x)) -> (fmul c+2, x)
5723 if (CFP00 && !CFP01 && N1.getOpcode() == ISD::FADD &&
5724 N1.getOperand(0) == N1.getOperand(1) &&
5725 N0.getOperand(1) == N1.getOperand(0)) {
5726 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5728 DAG.getConstantFP(2.0, VT));
5729 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5730 N0.getOperand(1), NewCFP);
5733 // (fadd (fmul x, c), (fadd x, x)) -> (fmul c+2, x)
5734 if (CFP01 && !CFP00 && N1.getOpcode() == ISD::FADD &&
5735 N1.getOperand(0) == N1.getOperand(1) &&
5736 N0.getOperand(0) == N1.getOperand(0)) {
5737 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5739 DAG.getConstantFP(2.0, VT));
5740 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5741 N0.getOperand(0), NewCFP);
5745 if (N1.getOpcode() == ISD::FMUL) {
5746 ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
5747 ConstantFPSDNode *CFP11 = dyn_cast<ConstantFPSDNode>(N1.getOperand(1));
5749 // (fadd x, (fmul c, x)) -> (fmul c+1, x)
5750 if (CFP10 && !CFP11 && N1.getOperand(1) == N0) {
5751 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5753 DAG.getConstantFP(1.0, VT));
5754 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5758 // (fadd x, (fmul x, c)) -> (fmul c+1, x)
5759 if (CFP11 && !CFP10 && N1.getOperand(0) == N0) {
5760 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5762 DAG.getConstantFP(1.0, VT));
5763 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5767 // (fadd x, (fadd x, x)) -> (fmul 3.0, x)
5768 if (!CFP10 && !CFP11 && N1.getOperand(0) == N1.getOperand(1) &&
5769 N1.getOperand(0) == N0) {
5770 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5771 N0, DAG.getConstantFP(3.0, VT));
5774 // (fadd (fadd x, x), (fmul c, x)) -> (fmul c+2, x)
5775 if (CFP10 && !CFP11 && N1.getOpcode() == ISD::FADD &&
5776 N1.getOperand(0) == N1.getOperand(1) &&
5777 N0.getOperand(1) == N1.getOperand(0)) {
5778 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5780 DAG.getConstantFP(2.0, VT));
5781 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5782 N0.getOperand(1), NewCFP);
5785 // (fadd (fadd x, x), (fmul x, c)) -> (fmul c+2, x)
5786 if (CFP11 && !CFP10 && N1.getOpcode() == ISD::FADD &&
5787 N1.getOperand(0) == N1.getOperand(1) &&
5788 N0.getOperand(0) == N1.getOperand(0)) {
5789 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5791 DAG.getConstantFP(2.0, VT));
5792 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5793 N0.getOperand(0), NewCFP);
5797 // (fadd (fadd x, x), (fadd x, x)) -> (fmul 4.0, x)
5798 if (N0.getOpcode() == ISD::FADD && N1.getOpcode() == ISD::FADD &&
5799 N0.getOperand(0) == N0.getOperand(1) &&
5800 N1.getOperand(0) == N1.getOperand(1) &&
5801 N0.getOperand(0) == N1.getOperand(0)) {
5802 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5804 DAG.getConstantFP(4.0, VT));
5808 // FADD -> FMA combines:
5809 if ((DAG.getTarget().Options.AllowFPOpFusion == FPOpFusion::Fast ||
5810 DAG.getTarget().Options.UnsafeFPMath) &&
5811 DAG.getTarget().getTargetLowering()->isFMAFasterThanMulAndAdd(VT) &&
5812 TLI.isOperationLegalOrCustom(ISD::FMA, VT)) {
5814 // fold (fadd (fmul x, y), z) -> (fma x, y, z)
5815 if (N0.getOpcode() == ISD::FMUL && N0->hasOneUse()) {
5816 return DAG.getNode(ISD::FMA, N->getDebugLoc(), VT,
5817 N0.getOperand(0), N0.getOperand(1), N1);
5820 // fold (fadd x, (fmul y, z)) -> (fma y, z, x)
5821 // Note: Commutes FADD operands.
5822 if (N1.getOpcode() == ISD::FMUL && N1->hasOneUse()) {
5823 return DAG.getNode(ISD::FMA, N->getDebugLoc(), VT,
5824 N1.getOperand(0), N1.getOperand(1), N0);
5831 SDValue DAGCombiner::visitFSUB(SDNode *N) {
5832 SDValue N0 = N->getOperand(0);
5833 SDValue N1 = N->getOperand(1);
5834 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
5835 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
5836 EVT VT = N->getValueType(0);
5837 DebugLoc dl = N->getDebugLoc();
5840 if (VT.isVector()) {
5841 SDValue FoldedVOp = SimplifyVBinOp(N);
5842 if (FoldedVOp.getNode()) return FoldedVOp;
5845 // fold (fsub c1, c2) -> c1-c2
5846 if (N0CFP && N1CFP && VT != MVT::ppcf128)
5847 return DAG.getNode(ISD::FSUB, N->getDebugLoc(), VT, N0, N1);
5848 // fold (fsub A, 0) -> A
5849 if (DAG.getTarget().Options.UnsafeFPMath &&
5850 N1CFP && N1CFP->getValueAPF().isZero())
5852 // fold (fsub 0, B) -> -B
5853 if (DAG.getTarget().Options.UnsafeFPMath &&
5854 N0CFP && N0CFP->getValueAPF().isZero()) {
5855 if (isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options))
5856 return GetNegatedExpression(N1, DAG, LegalOperations);
5857 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
5858 return DAG.getNode(ISD::FNEG, dl, VT, N1);
5860 // fold (fsub A, (fneg B)) -> (fadd A, B)
5861 if (isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options))
5862 return DAG.getNode(ISD::FADD, dl, VT, N0,
5863 GetNegatedExpression(N1, DAG, LegalOperations));
5865 // If 'unsafe math' is enabled, fold
5866 // (fsub x, x) -> 0.0 &
5867 // (fsub x, (fadd x, y)) -> (fneg y) &
5868 // (fsub x, (fadd y, x)) -> (fneg y)
5869 if (DAG.getTarget().Options.UnsafeFPMath) {
5871 return DAG.getConstantFP(0.0f, VT);
5873 if (N1.getOpcode() == ISD::FADD) {
5874 SDValue N10 = N1->getOperand(0);
5875 SDValue N11 = N1->getOperand(1);
5877 if (N10 == N0 && isNegatibleForFree(N11, LegalOperations, TLI,
5878 &DAG.getTarget().Options))
5879 return GetNegatedExpression(N11, DAG, LegalOperations);
5880 else if (N11 == N0 && isNegatibleForFree(N10, LegalOperations, TLI,
5881 &DAG.getTarget().Options))
5882 return GetNegatedExpression(N10, DAG, LegalOperations);
5886 // FSUB -> FMA combines:
5887 if ((DAG.getTarget().Options.AllowFPOpFusion == FPOpFusion::Fast ||
5888 DAG.getTarget().Options.UnsafeFPMath) &&
5889 DAG.getTarget().getTargetLowering()->isFMAFasterThanMulAndAdd(VT) &&
5890 TLI.isOperationLegalOrCustom(ISD::FMA, VT)) {
5892 // fold (fsub (fmul x, y), z) -> (fma x, y, (fneg z))
5893 if (N0.getOpcode() == ISD::FMUL && N0->hasOneUse()) {
5894 return DAG.getNode(ISD::FMA, dl, VT,
5895 N0.getOperand(0), N0.getOperand(1),
5896 DAG.getNode(ISD::FNEG, dl, VT, N1));
5899 // fold (fsub x, (fmul y, z)) -> (fma (fneg y), z, x)
5900 // Note: Commutes FSUB operands.
5901 if (N1.getOpcode() == ISD::FMUL && N1->hasOneUse()) {
5902 return DAG.getNode(ISD::FMA, dl, VT,
5903 DAG.getNode(ISD::FNEG, dl, VT,
5905 N1.getOperand(1), N0);
5908 // fold (fsub (-(fmul, x, y)), z) -> (fma (fneg x), y, (fneg z))
5909 if (N0.getOpcode() == ISD::FNEG &&
5910 N0.getOperand(0).getOpcode() == ISD::FMUL &&
5911 N0->hasOneUse() && N0.getOperand(0).hasOneUse()) {
5912 SDValue N00 = N0.getOperand(0).getOperand(0);
5913 SDValue N01 = N0.getOperand(0).getOperand(1);
5914 return DAG.getNode(ISD::FMA, dl, VT,
5915 DAG.getNode(ISD::FNEG, dl, VT, N00), N01,
5916 DAG.getNode(ISD::FNEG, dl, VT, N1));
5923 SDValue DAGCombiner::visitFMUL(SDNode *N) {
5924 SDValue N0 = N->getOperand(0);
5925 SDValue N1 = N->getOperand(1);
5926 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
5927 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
5928 EVT VT = N->getValueType(0);
5929 const TargetLowering &TLI = DAG.getTargetLoweringInfo();
5932 if (VT.isVector()) {
5933 SDValue FoldedVOp = SimplifyVBinOp(N);
5934 if (FoldedVOp.getNode()) return FoldedVOp;
5937 // fold (fmul c1, c2) -> c1*c2
5938 if (N0CFP && N1CFP && VT != MVT::ppcf128)
5939 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT, N0, N1);
5940 // canonicalize constant to RHS
5941 if (N0CFP && !N1CFP)
5942 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT, N1, N0);
5943 // fold (fmul A, 0) -> 0
5944 if (DAG.getTarget().Options.UnsafeFPMath &&
5945 N1CFP && N1CFP->getValueAPF().isZero())
5947 // fold (fmul A, 0) -> 0, vector edition.
5948 if (DAG.getTarget().Options.UnsafeFPMath &&
5949 ISD::isBuildVectorAllZeros(N1.getNode()))
5951 // fold (fmul A, 1.0) -> A
5952 if (N1CFP && N1CFP->isExactlyValue(1.0))
5954 // fold (fmul X, 2.0) -> (fadd X, X)
5955 if (N1CFP && N1CFP->isExactlyValue(+2.0))
5956 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0, N0);
5957 // fold (fmul X, -1.0) -> (fneg X)
5958 if (N1CFP && N1CFP->isExactlyValue(-1.0))
5959 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
5960 return DAG.getNode(ISD::FNEG, N->getDebugLoc(), VT, N0);
5962 // fold (fmul (fneg X), (fneg Y)) -> (fmul X, Y)
5963 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI,
5964 &DAG.getTarget().Options)) {
5965 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI,
5966 &DAG.getTarget().Options)) {
5967 // Both can be negated for free, check to see if at least one is cheaper
5969 if (LHSNeg == 2 || RHSNeg == 2)
5970 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5971 GetNegatedExpression(N0, DAG, LegalOperations),
5972 GetNegatedExpression(N1, DAG, LegalOperations));
5976 // If allowed, fold (fmul (fmul x, c1), c2) -> (fmul x, (fmul c1, c2))
5977 if (DAG.getTarget().Options.UnsafeFPMath &&
5978 N1CFP && N0.getOpcode() == ISD::FMUL &&
5979 N0.getNode()->hasOneUse() && isa<ConstantFPSDNode>(N0.getOperand(1)))
5980 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT, N0.getOperand(0),
5981 DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5982 N0.getOperand(1), N1));
5987 SDValue DAGCombiner::visitFMA(SDNode *N) {
5988 SDValue N0 = N->getOperand(0);
5989 SDValue N1 = N->getOperand(1);
5990 SDValue N2 = N->getOperand(2);
5991 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
5992 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
5993 EVT VT = N->getValueType(0);
5994 DebugLoc dl = N->getDebugLoc();
5996 if (N0CFP && N0CFP->isExactlyValue(1.0))
5997 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N1, N2);
5998 if (N1CFP && N1CFP->isExactlyValue(1.0))
5999 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0, N2);
6001 // Canonicalize (fma c, x, y) -> (fma x, c, y)
6002 if (N0CFP && !N1CFP)
6003 return DAG.getNode(ISD::FMA, N->getDebugLoc(), VT, N1, N0, N2);
6005 // (fma x, c1, (fmul x, c2)) -> (fmul x, c1+c2)
6006 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
6007 N2.getOpcode() == ISD::FMUL &&
6008 N0 == N2.getOperand(0) &&
6009 N2.getOperand(1).getOpcode() == ISD::ConstantFP) {
6010 return DAG.getNode(ISD::FMUL, dl, VT, N0,
6011 DAG.getNode(ISD::FADD, dl, VT, N1, N2.getOperand(1)));
6015 // (fma (fmul x, c1), c2, y) -> (fma x, c1*c2, y)
6016 if (DAG.getTarget().Options.UnsafeFPMath &&
6017 N0.getOpcode() == ISD::FMUL && N1CFP &&
6018 N0.getOperand(1).getOpcode() == ISD::ConstantFP) {
6019 return DAG.getNode(ISD::FMA, dl, VT,
6021 DAG.getNode(ISD::FMUL, dl, VT, N1, N0.getOperand(1)),
6025 // (fma x, 1, y) -> (fadd x, y)
6026 // (fma x, -1, y) -> (fadd (fneg x), y)
6028 if (N1CFP->isExactlyValue(1.0))
6029 return DAG.getNode(ISD::FADD, dl, VT, N0, N2);
6031 if (N1CFP->isExactlyValue(-1.0) &&
6032 (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))) {
6033 SDValue RHSNeg = DAG.getNode(ISD::FNEG, dl, VT, N0);
6034 AddToWorkList(RHSNeg.getNode());
6035 return DAG.getNode(ISD::FADD, dl, VT, N2, RHSNeg);
6039 // (fma x, c, x) -> (fmul x, (c+1))
6040 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP && N0 == N2) {
6041 return DAG.getNode(ISD::FMUL, dl, VT,
6043 DAG.getNode(ISD::FADD, dl, VT,
6044 N1, DAG.getConstantFP(1.0, VT)));
6047 // (fma x, c, (fneg x)) -> (fmul x, (c-1))
6048 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
6049 N2.getOpcode() == ISD::FNEG && N2.getOperand(0) == N0) {
6050 return DAG.getNode(ISD::FMUL, dl, VT,
6052 DAG.getNode(ISD::FADD, dl, VT,
6053 N1, DAG.getConstantFP(-1.0, VT)));
6060 SDValue DAGCombiner::visitFDIV(SDNode *N) {
6061 SDValue N0 = N->getOperand(0);
6062 SDValue N1 = N->getOperand(1);
6063 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6064 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6065 EVT VT = N->getValueType(0);
6066 const TargetLowering &TLI = DAG.getTargetLoweringInfo();
6069 if (VT.isVector()) {
6070 SDValue FoldedVOp = SimplifyVBinOp(N);
6071 if (FoldedVOp.getNode()) return FoldedVOp;
6074 // fold (fdiv c1, c2) -> c1/c2
6075 if (N0CFP && N1CFP && VT != MVT::ppcf128)
6076 return DAG.getNode(ISD::FDIV, N->getDebugLoc(), VT, N0, N1);
6078 // fold (fdiv X, c2) -> fmul X, 1/c2 if losing precision is acceptable.
6079 if (N1CFP && VT != MVT::ppcf128 && DAG.getTarget().Options.UnsafeFPMath) {
6080 // Compute the reciprocal 1.0 / c2.
6081 APFloat N1APF = N1CFP->getValueAPF();
6082 APFloat Recip(N1APF.getSemantics(), 1); // 1.0
6083 APFloat::opStatus st = Recip.divide(N1APF, APFloat::rmNearestTiesToEven);
6084 // Only do the transform if the reciprocal is a legal fp immediate that
6085 // isn't too nasty (eg NaN, denormal, ...).
6086 if ((st == APFloat::opOK || st == APFloat::opInexact) && // Not too nasty
6087 (!LegalOperations ||
6088 // FIXME: custom lowering of ConstantFP might fail (see e.g. ARM
6089 // backend)... we should handle this gracefully after Legalize.
6090 // TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT) ||
6091 TLI.isOperationLegal(llvm::ISD::ConstantFP, VT) ||
6092 TLI.isFPImmLegal(Recip, VT)))
6093 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT, N0,
6094 DAG.getConstantFP(Recip, VT));
6097 // (fdiv (fneg X), (fneg Y)) -> (fdiv X, Y)
6098 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI,
6099 &DAG.getTarget().Options)) {
6100 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI,
6101 &DAG.getTarget().Options)) {
6102 // Both can be negated for free, check to see if at least one is cheaper
6104 if (LHSNeg == 2 || RHSNeg == 2)
6105 return DAG.getNode(ISD::FDIV, N->getDebugLoc(), VT,
6106 GetNegatedExpression(N0, DAG, LegalOperations),
6107 GetNegatedExpression(N1, DAG, LegalOperations));
6114 SDValue DAGCombiner::visitFREM(SDNode *N) {
6115 SDValue N0 = N->getOperand(0);
6116 SDValue N1 = N->getOperand(1);
6117 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6118 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6119 EVT VT = N->getValueType(0);
6121 // fold (frem c1, c2) -> fmod(c1,c2)
6122 if (N0CFP && N1CFP && VT != MVT::ppcf128)
6123 return DAG.getNode(ISD::FREM, N->getDebugLoc(), VT, N0, N1);
6128 SDValue DAGCombiner::visitFCOPYSIGN(SDNode *N) {
6129 SDValue N0 = N->getOperand(0);
6130 SDValue N1 = N->getOperand(1);
6131 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6132 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6133 EVT VT = N->getValueType(0);
6135 if (N0CFP && N1CFP && VT != MVT::ppcf128) // Constant fold
6136 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT, N0, N1);
6139 const APFloat& V = N1CFP->getValueAPF();
6140 // copysign(x, c1) -> fabs(x) iff ispos(c1)
6141 // copysign(x, c1) -> fneg(fabs(x)) iff isneg(c1)
6142 if (!V.isNegative()) {
6143 if (!LegalOperations || TLI.isOperationLegal(ISD::FABS, VT))
6144 return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0);
6146 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
6147 return DAG.getNode(ISD::FNEG, N->getDebugLoc(), VT,
6148 DAG.getNode(ISD::FABS, N0.getDebugLoc(), VT, N0));
6152 // copysign(fabs(x), y) -> copysign(x, y)
6153 // copysign(fneg(x), y) -> copysign(x, y)
6154 // copysign(copysign(x,z), y) -> copysign(x, y)
6155 if (N0.getOpcode() == ISD::FABS || N0.getOpcode() == ISD::FNEG ||
6156 N0.getOpcode() == ISD::FCOPYSIGN)
6157 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT,
6158 N0.getOperand(0), N1);
6160 // copysign(x, abs(y)) -> abs(x)
6161 if (N1.getOpcode() == ISD::FABS)
6162 return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0);
6164 // copysign(x, copysign(y,z)) -> copysign(x, z)
6165 if (N1.getOpcode() == ISD::FCOPYSIGN)
6166 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT,
6167 N0, N1.getOperand(1));
6169 // copysign(x, fp_extend(y)) -> copysign(x, y)
6170 // copysign(x, fp_round(y)) -> copysign(x, y)
6171 if (N1.getOpcode() == ISD::FP_EXTEND || N1.getOpcode() == ISD::FP_ROUND)
6172 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT,
6173 N0, N1.getOperand(0));
6178 SDValue DAGCombiner::visitSINT_TO_FP(SDNode *N) {
6179 SDValue N0 = N->getOperand(0);
6180 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
6181 EVT VT = N->getValueType(0);
6182 EVT OpVT = N0.getValueType();
6184 // fold (sint_to_fp c1) -> c1fp
6185 if (N0C && OpVT != MVT::ppcf128 &&
6186 // ...but only if the target supports immediate floating-point values
6187 (!LegalOperations ||
6188 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT)))
6189 return DAG.getNode(ISD::SINT_TO_FP, N->getDebugLoc(), VT, N0);
6191 // If the input is a legal type, and SINT_TO_FP is not legal on this target,
6192 // but UINT_TO_FP is legal on this target, try to convert.
6193 if (!TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT) &&
6194 TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT)) {
6195 // If the sign bit is known to be zero, we can change this to UINT_TO_FP.
6196 if (DAG.SignBitIsZero(N0))
6197 return DAG.getNode(ISD::UINT_TO_FP, N->getDebugLoc(), VT, N0);
6200 // The next optimizations are desireable only if SELECT_CC can be lowered.
6201 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
6202 // having to say they don't support SELECT_CC on every type the DAG knows
6203 // about, since there is no way to mark an opcode illegal at all value types
6204 // (See also visitSELECT)
6205 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other)) {
6206 // fold (sint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
6207 if (N0.getOpcode() == ISD::SETCC && N0.getValueType() == MVT::i1 &&
6209 (!LegalOperations ||
6210 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
6212 { N0.getOperand(0), N0.getOperand(1),
6213 DAG.getConstantFP(-1.0, VT) , DAG.getConstantFP(0.0, VT),
6215 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT, Ops, 5);
6218 // fold (sint_to_fp (zext (setcc x, y, cc))) ->
6219 // (select_cc x, y, 1.0, 0.0,, cc)
6220 if (N0.getOpcode() == ISD::ZERO_EXTEND &&
6221 N0.getOperand(0).getOpcode() == ISD::SETCC &&!VT.isVector() &&
6222 (!LegalOperations ||
6223 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
6225 { N0.getOperand(0).getOperand(0), N0.getOperand(0).getOperand(1),
6226 DAG.getConstantFP(1.0, VT) , DAG.getConstantFP(0.0, VT),
6227 N0.getOperand(0).getOperand(2) };
6228 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT, Ops, 5);
6235 SDValue DAGCombiner::visitUINT_TO_FP(SDNode *N) {
6236 SDValue N0 = N->getOperand(0);
6237 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
6238 EVT VT = N->getValueType(0);
6239 EVT OpVT = N0.getValueType();
6241 // fold (uint_to_fp c1) -> c1fp
6242 if (N0C && OpVT != MVT::ppcf128 &&
6243 // ...but only if the target supports immediate floating-point values
6244 (!LegalOperations ||
6245 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT)))
6246 return DAG.getNode(ISD::UINT_TO_FP, N->getDebugLoc(), VT, N0);
6248 // If the input is a legal type, and UINT_TO_FP is not legal on this target,
6249 // but SINT_TO_FP is legal on this target, try to convert.
6250 if (!TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT) &&
6251 TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT)) {
6252 // If the sign bit is known to be zero, we can change this to SINT_TO_FP.
6253 if (DAG.SignBitIsZero(N0))
6254 return DAG.getNode(ISD::SINT_TO_FP, N->getDebugLoc(), VT, N0);
6257 // The next optimizations are desireable only if SELECT_CC can be lowered.
6258 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
6259 // having to say they don't support SELECT_CC on every type the DAG knows
6260 // about, since there is no way to mark an opcode illegal at all value types
6261 // (See also visitSELECT)
6262 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other)) {
6263 // fold (uint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
6265 if (N0.getOpcode() == ISD::SETCC && !VT.isVector() &&
6266 (!LegalOperations ||
6267 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
6269 { N0.getOperand(0), N0.getOperand(1),
6270 DAG.getConstantFP(1.0, VT), DAG.getConstantFP(0.0, VT),
6272 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT, Ops, 5);
6279 SDValue DAGCombiner::visitFP_TO_SINT(SDNode *N) {
6280 SDValue N0 = N->getOperand(0);
6281 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6282 EVT VT = N->getValueType(0);
6284 // fold (fp_to_sint c1fp) -> c1
6286 return DAG.getNode(ISD::FP_TO_SINT, N->getDebugLoc(), VT, N0);
6291 SDValue DAGCombiner::visitFP_TO_UINT(SDNode *N) {
6292 SDValue N0 = N->getOperand(0);
6293 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6294 EVT VT = N->getValueType(0);
6296 // fold (fp_to_uint c1fp) -> c1
6297 if (N0CFP && VT != MVT::ppcf128)
6298 return DAG.getNode(ISD::FP_TO_UINT, N->getDebugLoc(), VT, N0);
6303 SDValue DAGCombiner::visitFP_ROUND(SDNode *N) {
6304 SDValue N0 = N->getOperand(0);
6305 SDValue N1 = N->getOperand(1);
6306 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6307 EVT VT = N->getValueType(0);
6309 // fold (fp_round c1fp) -> c1fp
6310 if (N0CFP && N0.getValueType() != MVT::ppcf128)
6311 return DAG.getNode(ISD::FP_ROUND, N->getDebugLoc(), VT, N0, N1);
6313 // fold (fp_round (fp_extend x)) -> x
6314 if (N0.getOpcode() == ISD::FP_EXTEND && VT == N0.getOperand(0).getValueType())
6315 return N0.getOperand(0);
6317 // fold (fp_round (fp_round x)) -> (fp_round x)
6318 if (N0.getOpcode() == ISD::FP_ROUND) {
6319 // This is a value preserving truncation if both round's are.
6320 bool IsTrunc = N->getConstantOperandVal(1) == 1 &&
6321 N0.getNode()->getConstantOperandVal(1) == 1;
6322 return DAG.getNode(ISD::FP_ROUND, N->getDebugLoc(), VT, N0.getOperand(0),
6323 DAG.getIntPtrConstant(IsTrunc));
6326 // fold (fp_round (copysign X, Y)) -> (copysign (fp_round X), Y)
6327 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse()) {
6328 SDValue Tmp = DAG.getNode(ISD::FP_ROUND, N0.getDebugLoc(), VT,
6329 N0.getOperand(0), N1);
6330 AddToWorkList(Tmp.getNode());
6331 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT,
6332 Tmp, N0.getOperand(1));
6338 SDValue DAGCombiner::visitFP_ROUND_INREG(SDNode *N) {
6339 SDValue N0 = N->getOperand(0);
6340 EVT VT = N->getValueType(0);
6341 EVT EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
6342 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6344 // fold (fp_round_inreg c1fp) -> c1fp
6345 if (N0CFP && isTypeLegal(EVT)) {
6346 SDValue Round = DAG.getConstantFP(*N0CFP->getConstantFPValue(), EVT);
6347 return DAG.getNode(ISD::FP_EXTEND, N->getDebugLoc(), VT, Round);
6353 SDValue DAGCombiner::visitFP_EXTEND(SDNode *N) {
6354 SDValue N0 = N->getOperand(0);
6355 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6356 EVT VT = N->getValueType(0);
6358 // If this is fp_round(fpextend), don't fold it, allow ourselves to be folded.
6359 if (N->hasOneUse() &&
6360 N->use_begin()->getOpcode() == ISD::FP_ROUND)
6363 // fold (fp_extend c1fp) -> c1fp
6364 if (N0CFP && VT != MVT::ppcf128)
6365 return DAG.getNode(ISD::FP_EXTEND, N->getDebugLoc(), VT, N0);
6367 // Turn fp_extend(fp_round(X, 1)) -> x since the fp_round doesn't affect the
6369 if (N0.getOpcode() == ISD::FP_ROUND
6370 && N0.getNode()->getConstantOperandVal(1) == 1) {
6371 SDValue In = N0.getOperand(0);
6372 if (In.getValueType() == VT) return In;
6373 if (VT.bitsLT(In.getValueType()))
6374 return DAG.getNode(ISD::FP_ROUND, N->getDebugLoc(), VT,
6375 In, N0.getOperand(1));
6376 return DAG.getNode(ISD::FP_EXTEND, N->getDebugLoc(), VT, In);
6379 // fold (fpext (load x)) -> (fpext (fptrunc (extload x)))
6380 if (ISD::isNON_EXTLoad(N0.getNode()) && N0.hasOneUse() &&
6381 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
6382 TLI.isLoadExtLegal(ISD::EXTLOAD, N0.getValueType()))) {
6383 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6384 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, N->getDebugLoc(), VT,
6386 LN0->getBasePtr(), LN0->getPointerInfo(),
6388 LN0->isVolatile(), LN0->isNonTemporal(),
6389 LN0->getAlignment());
6390 CombineTo(N, ExtLoad);
6391 CombineTo(N0.getNode(),
6392 DAG.getNode(ISD::FP_ROUND, N0.getDebugLoc(),
6393 N0.getValueType(), ExtLoad, DAG.getIntPtrConstant(1)),
6394 ExtLoad.getValue(1));
6395 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6401 SDValue DAGCombiner::visitFNEG(SDNode *N) {
6402 SDValue N0 = N->getOperand(0);
6403 EVT VT = N->getValueType(0);
6405 if (VT.isVector()) {
6406 SDValue FoldedVOp = SimplifyVUnaryOp(N);
6407 if (FoldedVOp.getNode()) return FoldedVOp;
6410 if (isNegatibleForFree(N0, LegalOperations, DAG.getTargetLoweringInfo(),
6411 &DAG.getTarget().Options))
6412 return GetNegatedExpression(N0, DAG, LegalOperations);
6414 // Transform fneg(bitconvert(x)) -> bitconvert(x^sign) to avoid loading
6415 // constant pool values.
6416 if (!TLI.isFNegFree(VT) && N0.getOpcode() == ISD::BITCAST &&
6418 N0.getNode()->hasOneUse() &&
6419 N0.getOperand(0).getValueType().isInteger()) {
6420 SDValue Int = N0.getOperand(0);
6421 EVT IntVT = Int.getValueType();
6422 if (IntVT.isInteger() && !IntVT.isVector()) {
6423 Int = DAG.getNode(ISD::XOR, N0.getDebugLoc(), IntVT, Int,
6424 DAG.getConstant(APInt::getSignBit(IntVT.getSizeInBits()), IntVT));
6425 AddToWorkList(Int.getNode());
6426 return DAG.getNode(ISD::BITCAST, N->getDebugLoc(),
6431 // (fneg (fmul c, x)) -> (fmul -c, x)
6432 if (N0.getOpcode() == ISD::FMUL) {
6433 ConstantFPSDNode *CFP1 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
6435 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
6437 DAG.getNode(ISD::FNEG, N->getDebugLoc(), VT,
6445 SDValue DAGCombiner::visitFCEIL(SDNode *N) {
6446 SDValue N0 = N->getOperand(0);
6447 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6448 EVT VT = N->getValueType(0);
6450 // fold (fceil c1) -> fceil(c1)
6451 if (N0CFP && VT != MVT::ppcf128)
6452 return DAG.getNode(ISD::FCEIL, N->getDebugLoc(), VT, N0);
6457 SDValue DAGCombiner::visitFTRUNC(SDNode *N) {
6458 SDValue N0 = N->getOperand(0);
6459 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6460 EVT VT = N->getValueType(0);
6462 // fold (ftrunc c1) -> ftrunc(c1)
6463 if (N0CFP && VT != MVT::ppcf128)
6464 return DAG.getNode(ISD::FTRUNC, N->getDebugLoc(), VT, N0);
6469 SDValue DAGCombiner::visitFFLOOR(SDNode *N) {
6470 SDValue N0 = N->getOperand(0);
6471 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6472 EVT VT = N->getValueType(0);
6474 // fold (ffloor c1) -> ffloor(c1)
6475 if (N0CFP && VT != MVT::ppcf128)
6476 return DAG.getNode(ISD::FFLOOR, N->getDebugLoc(), VT, N0);
6481 SDValue DAGCombiner::visitFABS(SDNode *N) {
6482 SDValue N0 = N->getOperand(0);
6483 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6484 EVT VT = N->getValueType(0);
6486 if (VT.isVector()) {
6487 SDValue FoldedVOp = SimplifyVUnaryOp(N);
6488 if (FoldedVOp.getNode()) return FoldedVOp;
6491 // fold (fabs c1) -> fabs(c1)
6492 if (N0CFP && VT != MVT::ppcf128)
6493 return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0);
6494 // fold (fabs (fabs x)) -> (fabs x)
6495 if (N0.getOpcode() == ISD::FABS)
6496 return N->getOperand(0);
6497 // fold (fabs (fneg x)) -> (fabs x)
6498 // fold (fabs (fcopysign x, y)) -> (fabs x)
6499 if (N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FCOPYSIGN)
6500 return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0.getOperand(0));
6502 // Transform fabs(bitconvert(x)) -> bitconvert(x&~sign) to avoid loading
6503 // constant pool values.
6504 if (!TLI.isFAbsFree(VT) &&
6505 N0.getOpcode() == ISD::BITCAST && N0.getNode()->hasOneUse() &&
6506 N0.getOperand(0).getValueType().isInteger() &&
6507 !N0.getOperand(0).getValueType().isVector()) {
6508 SDValue Int = N0.getOperand(0);
6509 EVT IntVT = Int.getValueType();
6510 if (IntVT.isInteger() && !IntVT.isVector()) {
6511 Int = DAG.getNode(ISD::AND, N0.getDebugLoc(), IntVT, Int,
6512 DAG.getConstant(~APInt::getSignBit(IntVT.getSizeInBits()), IntVT));
6513 AddToWorkList(Int.getNode());
6514 return DAG.getNode(ISD::BITCAST, N->getDebugLoc(),
6515 N->getValueType(0), Int);
6522 SDValue DAGCombiner::visitBRCOND(SDNode *N) {
6523 SDValue Chain = N->getOperand(0);
6524 SDValue N1 = N->getOperand(1);
6525 SDValue N2 = N->getOperand(2);
6527 // If N is a constant we could fold this into a fallthrough or unconditional
6528 // branch. However that doesn't happen very often in normal code, because
6529 // Instcombine/SimplifyCFG should have handled the available opportunities.
6530 // If we did this folding here, it would be necessary to update the
6531 // MachineBasicBlock CFG, which is awkward.
6533 // fold a brcond with a setcc condition into a BR_CC node if BR_CC is legal
6535 if (N1.getOpcode() == ISD::SETCC &&
6536 TLI.isOperationLegalOrCustom(ISD::BR_CC, MVT::Other)) {
6537 return DAG.getNode(ISD::BR_CC, N->getDebugLoc(), MVT::Other,
6538 Chain, N1.getOperand(2),
6539 N1.getOperand(0), N1.getOperand(1), N2);
6542 if ((N1.hasOneUse() && N1.getOpcode() == ISD::SRL) ||
6543 ((N1.getOpcode() == ISD::TRUNCATE && N1.hasOneUse()) &&
6544 (N1.getOperand(0).hasOneUse() &&
6545 N1.getOperand(0).getOpcode() == ISD::SRL))) {
6547 if (N1.getOpcode() == ISD::TRUNCATE) {
6548 // Look pass the truncate.
6549 Trunc = N1.getNode();
6550 N1 = N1.getOperand(0);
6553 // Match this pattern so that we can generate simpler code:
6556 // %b = and i32 %a, 2
6557 // %c = srl i32 %b, 1
6558 // brcond i32 %c ...
6563 // %b = and i32 %a, 2
6564 // %c = setcc eq %b, 0
6567 // This applies only when the AND constant value has one bit set and the
6568 // SRL constant is equal to the log2 of the AND constant. The back-end is
6569 // smart enough to convert the result into a TEST/JMP sequence.
6570 SDValue Op0 = N1.getOperand(0);
6571 SDValue Op1 = N1.getOperand(1);
6573 if (Op0.getOpcode() == ISD::AND &&
6574 Op1.getOpcode() == ISD::Constant) {
6575 SDValue AndOp1 = Op0.getOperand(1);
6577 if (AndOp1.getOpcode() == ISD::Constant) {
6578 const APInt &AndConst = cast<ConstantSDNode>(AndOp1)->getAPIntValue();
6580 if (AndConst.isPowerOf2() &&
6581 cast<ConstantSDNode>(Op1)->getAPIntValue()==AndConst.logBase2()) {
6583 DAG.getSetCC(N->getDebugLoc(),
6584 TLI.getSetCCResultType(Op0.getValueType()),
6585 Op0, DAG.getConstant(0, Op0.getValueType()),
6588 SDValue NewBRCond = DAG.getNode(ISD::BRCOND, N->getDebugLoc(),
6589 MVT::Other, Chain, SetCC, N2);
6590 // Don't add the new BRCond into the worklist or else SimplifySelectCC
6591 // will convert it back to (X & C1) >> C2.
6592 CombineTo(N, NewBRCond, false);
6593 // Truncate is dead.
6595 removeFromWorkList(Trunc);
6596 DAG.DeleteNode(Trunc);
6598 // Replace the uses of SRL with SETCC
6599 WorkListRemover DeadNodes(*this);
6600 DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
6601 removeFromWorkList(N1.getNode());
6602 DAG.DeleteNode(N1.getNode());
6603 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6609 // Restore N1 if the above transformation doesn't match.
6610 N1 = N->getOperand(1);
6613 // Transform br(xor(x, y)) -> br(x != y)
6614 // Transform br(xor(xor(x,y), 1)) -> br (x == y)
6615 if (N1.hasOneUse() && N1.getOpcode() == ISD::XOR) {
6616 SDNode *TheXor = N1.getNode();
6617 SDValue Op0 = TheXor->getOperand(0);
6618 SDValue Op1 = TheXor->getOperand(1);
6619 if (Op0.getOpcode() == Op1.getOpcode()) {
6620 // Avoid missing important xor optimizations.
6621 SDValue Tmp = visitXOR(TheXor);
6622 if (Tmp.getNode() && Tmp.getNode() != TheXor) {
6623 DEBUG(dbgs() << "\nReplacing.8 ";
6625 dbgs() << "\nWith: ";
6626 Tmp.getNode()->dump(&DAG);
6628 WorkListRemover DeadNodes(*this);
6629 DAG.ReplaceAllUsesOfValueWith(N1, Tmp);
6630 removeFromWorkList(TheXor);
6631 DAG.DeleteNode(TheXor);
6632 return DAG.getNode(ISD::BRCOND, N->getDebugLoc(),
6633 MVT::Other, Chain, Tmp, N2);
6637 if (Op0.getOpcode() != ISD::SETCC && Op1.getOpcode() != ISD::SETCC) {
6639 if (ConstantSDNode *RHSCI = dyn_cast<ConstantSDNode>(Op0))
6640 if (RHSCI->getAPIntValue() == 1 && Op0.hasOneUse() &&
6641 Op0.getOpcode() == ISD::XOR) {
6642 TheXor = Op0.getNode();
6646 EVT SetCCVT = N1.getValueType();
6648 SetCCVT = TLI.getSetCCResultType(SetCCVT);
6649 SDValue SetCC = DAG.getSetCC(TheXor->getDebugLoc(),
6652 Equal ? ISD::SETEQ : ISD::SETNE);
6653 // Replace the uses of XOR with SETCC
6654 WorkListRemover DeadNodes(*this);
6655 DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
6656 removeFromWorkList(N1.getNode());
6657 DAG.DeleteNode(N1.getNode());
6658 return DAG.getNode(ISD::BRCOND, N->getDebugLoc(),
6659 MVT::Other, Chain, SetCC, N2);
6666 // Operand List for BR_CC: Chain, CondCC, CondLHS, CondRHS, DestBB.
6668 SDValue DAGCombiner::visitBR_CC(SDNode *N) {
6669 CondCodeSDNode *CC = cast<CondCodeSDNode>(N->getOperand(1));
6670 SDValue CondLHS = N->getOperand(2), CondRHS = N->getOperand(3);
6672 // If N is a constant we could fold this into a fallthrough or unconditional
6673 // branch. However that doesn't happen very often in normal code, because
6674 // Instcombine/SimplifyCFG should have handled the available opportunities.
6675 // If we did this folding here, it would be necessary to update the
6676 // MachineBasicBlock CFG, which is awkward.
6678 // Use SimplifySetCC to simplify SETCC's.
6679 SDValue Simp = SimplifySetCC(TLI.getSetCCResultType(CondLHS.getValueType()),
6680 CondLHS, CondRHS, CC->get(), N->getDebugLoc(),
6682 if (Simp.getNode()) AddToWorkList(Simp.getNode());
6684 // fold to a simpler setcc
6685 if (Simp.getNode() && Simp.getOpcode() == ISD::SETCC)
6686 return DAG.getNode(ISD::BR_CC, N->getDebugLoc(), MVT::Other,
6687 N->getOperand(0), Simp.getOperand(2),
6688 Simp.getOperand(0), Simp.getOperand(1),
6694 /// canFoldInAddressingMode - Return true if 'Use' is a load or a store that
6695 /// uses N as its base pointer and that N may be folded in the load / store
6696 /// addressing mode.
6697 static bool canFoldInAddressingMode(SDNode *N, SDNode *Use,
6699 const TargetLowering &TLI) {
6701 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Use)) {
6702 if (LD->isIndexed() || LD->getBasePtr().getNode() != N)
6704 VT = Use->getValueType(0);
6705 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(Use)) {
6706 if (ST->isIndexed() || ST->getBasePtr().getNode() != N)
6708 VT = ST->getValue().getValueType();
6712 TargetLowering::AddrMode AM;
6713 if (N->getOpcode() == ISD::ADD) {
6714 ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
6717 AM.BaseOffs = Offset->getSExtValue();
6721 } else if (N->getOpcode() == ISD::SUB) {
6722 ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
6725 AM.BaseOffs = -Offset->getSExtValue();
6732 return TLI.isLegalAddressingMode(AM, VT.getTypeForEVT(*DAG.getContext()));
6735 /// CombineToPreIndexedLoadStore - Try turning a load / store into a
6736 /// pre-indexed load / store when the base pointer is an add or subtract
6737 /// and it has other uses besides the load / store. After the
6738 /// transformation, the new indexed load / store has effectively folded
6739 /// the add / subtract in and all of its other uses are redirected to the
6740 /// new load / store.
6741 bool DAGCombiner::CombineToPreIndexedLoadStore(SDNode *N) {
6742 if (Level < AfterLegalizeDAG)
6748 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
6749 if (LD->isIndexed())
6751 VT = LD->getMemoryVT();
6752 if (!TLI.isIndexedLoadLegal(ISD::PRE_INC, VT) &&
6753 !TLI.isIndexedLoadLegal(ISD::PRE_DEC, VT))
6755 Ptr = LD->getBasePtr();
6756 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
6757 if (ST->isIndexed())
6759 VT = ST->getMemoryVT();
6760 if (!TLI.isIndexedStoreLegal(ISD::PRE_INC, VT) &&
6761 !TLI.isIndexedStoreLegal(ISD::PRE_DEC, VT))
6763 Ptr = ST->getBasePtr();
6769 // If the pointer is not an add/sub, or if it doesn't have multiple uses, bail
6770 // out. There is no reason to make this a preinc/predec.
6771 if ((Ptr.getOpcode() != ISD::ADD && Ptr.getOpcode() != ISD::SUB) ||
6772 Ptr.getNode()->hasOneUse())
6775 // Ask the target to do addressing mode selection.
6778 ISD::MemIndexedMode AM = ISD::UNINDEXED;
6779 if (!TLI.getPreIndexedAddressParts(N, BasePtr, Offset, AM, DAG))
6781 // Don't create a indexed load / store with zero offset.
6782 if (isa<ConstantSDNode>(Offset) &&
6783 cast<ConstantSDNode>(Offset)->isNullValue())
6786 // Try turning it into a pre-indexed load / store except when:
6787 // 1) The new base ptr is a frame index.
6788 // 2) If N is a store and the new base ptr is either the same as or is a
6789 // predecessor of the value being stored.
6790 // 3) Another use of old base ptr is a predecessor of N. If ptr is folded
6791 // that would create a cycle.
6792 // 4) All uses are load / store ops that use it as old base ptr.
6794 // Check #1. Preinc'ing a frame index would require copying the stack pointer
6795 // (plus the implicit offset) to a register to preinc anyway.
6796 if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
6801 SDValue Val = cast<StoreSDNode>(N)->getValue();
6802 if (Val == BasePtr || BasePtr.getNode()->isPredecessorOf(Val.getNode()))
6806 // Now check for #3 and #4.
6807 bool RealUse = false;
6809 // Caches for hasPredecessorHelper
6810 SmallPtrSet<const SDNode *, 32> Visited;
6811 SmallVector<const SDNode *, 16> Worklist;
6813 for (SDNode::use_iterator I = Ptr.getNode()->use_begin(),
6814 E = Ptr.getNode()->use_end(); I != E; ++I) {
6818 if (N->hasPredecessorHelper(Use, Visited, Worklist))
6821 // If Ptr may be folded in addressing mode of other use, then it's
6822 // not profitable to do this transformation.
6823 if (!canFoldInAddressingMode(Ptr.getNode(), Use, DAG, TLI))
6832 Result = DAG.getIndexedLoad(SDValue(N,0), N->getDebugLoc(),
6833 BasePtr, Offset, AM);
6835 Result = DAG.getIndexedStore(SDValue(N,0), N->getDebugLoc(),
6836 BasePtr, Offset, AM);
6839 DEBUG(dbgs() << "\nReplacing.4 ";
6841 dbgs() << "\nWith: ";
6842 Result.getNode()->dump(&DAG);
6844 WorkListRemover DeadNodes(*this);
6846 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
6847 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
6849 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
6852 // Finally, since the node is now dead, remove it from the graph.
6855 // Replace the uses of Ptr with uses of the updated base value.
6856 DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0));
6857 removeFromWorkList(Ptr.getNode());
6858 DAG.DeleteNode(Ptr.getNode());
6863 /// CombineToPostIndexedLoadStore - Try to combine a load / store with a
6864 /// add / sub of the base pointer node into a post-indexed load / store.
6865 /// The transformation folded the add / subtract into the new indexed
6866 /// load / store effectively and all of its uses are redirected to the
6867 /// new load / store.
6868 bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
6869 if (Level < AfterLegalizeDAG)
6875 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
6876 if (LD->isIndexed())
6878 VT = LD->getMemoryVT();
6879 if (!TLI.isIndexedLoadLegal(ISD::POST_INC, VT) &&
6880 !TLI.isIndexedLoadLegal(ISD::POST_DEC, VT))
6882 Ptr = LD->getBasePtr();
6883 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
6884 if (ST->isIndexed())
6886 VT = ST->getMemoryVT();
6887 if (!TLI.isIndexedStoreLegal(ISD::POST_INC, VT) &&
6888 !TLI.isIndexedStoreLegal(ISD::POST_DEC, VT))
6890 Ptr = ST->getBasePtr();
6896 if (Ptr.getNode()->hasOneUse())
6899 for (SDNode::use_iterator I = Ptr.getNode()->use_begin(),
6900 E = Ptr.getNode()->use_end(); I != E; ++I) {
6903 (Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB))
6908 ISD::MemIndexedMode AM = ISD::UNINDEXED;
6909 if (TLI.getPostIndexedAddressParts(N, Op, BasePtr, Offset, AM, DAG)) {
6910 // Don't create a indexed load / store with zero offset.
6911 if (isa<ConstantSDNode>(Offset) &&
6912 cast<ConstantSDNode>(Offset)->isNullValue())
6915 // Try turning it into a post-indexed load / store except when
6916 // 1) All uses are load / store ops that use it as base ptr (and
6917 // it may be folded as addressing mmode).
6918 // 2) Op must be independent of N, i.e. Op is neither a predecessor
6919 // nor a successor of N. Otherwise, if Op is folded that would
6922 if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
6926 bool TryNext = false;
6927 for (SDNode::use_iterator II = BasePtr.getNode()->use_begin(),
6928 EE = BasePtr.getNode()->use_end(); II != EE; ++II) {
6930 if (Use == Ptr.getNode())
6933 // If all the uses are load / store addresses, then don't do the
6935 if (Use->getOpcode() == ISD::ADD || Use->getOpcode() == ISD::SUB){
6936 bool RealUse = false;
6937 for (SDNode::use_iterator III = Use->use_begin(),
6938 EEE = Use->use_end(); III != EEE; ++III) {
6939 SDNode *UseUse = *III;
6940 if (!canFoldInAddressingMode(Use, UseUse, DAG, TLI))
6955 if (!Op->isPredecessorOf(N) && !N->isPredecessorOf(Op)) {
6956 SDValue Result = isLoad
6957 ? DAG.getIndexedLoad(SDValue(N,0), N->getDebugLoc(),
6958 BasePtr, Offset, AM)
6959 : DAG.getIndexedStore(SDValue(N,0), N->getDebugLoc(),
6960 BasePtr, Offset, AM);
6963 DEBUG(dbgs() << "\nReplacing.5 ";
6965 dbgs() << "\nWith: ";
6966 Result.getNode()->dump(&DAG);
6968 WorkListRemover DeadNodes(*this);
6970 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
6971 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
6973 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
6976 // Finally, since the node is now dead, remove it from the graph.
6979 // Replace the uses of Use with uses of the updated base value.
6980 DAG.ReplaceAllUsesOfValueWith(SDValue(Op, 0),
6981 Result.getValue(isLoad ? 1 : 0));
6982 removeFromWorkList(Op);
6992 SDValue DAGCombiner::visitLOAD(SDNode *N) {
6993 LoadSDNode *LD = cast<LoadSDNode>(N);
6994 SDValue Chain = LD->getChain();
6995 SDValue Ptr = LD->getBasePtr();
6997 // If load is not volatile and there are no uses of the loaded value (and
6998 // the updated indexed value in case of indexed loads), change uses of the
6999 // chain value into uses of the chain input (i.e. delete the dead load).
7000 if (!LD->isVolatile()) {
7001 if (N->getValueType(1) == MVT::Other) {
7003 if (!N->hasAnyUseOfValue(0)) {
7004 // It's not safe to use the two value CombineTo variant here. e.g.
7005 // v1, chain2 = load chain1, loc
7006 // v2, chain3 = load chain2, loc
7008 // Now we replace use of chain2 with chain1. This makes the second load
7009 // isomorphic to the one we are deleting, and thus makes this load live.
7010 DEBUG(dbgs() << "\nReplacing.6 ";
7012 dbgs() << "\nWith chain: ";
7013 Chain.getNode()->dump(&DAG);
7015 WorkListRemover DeadNodes(*this);
7016 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain);
7018 if (N->use_empty()) {
7019 removeFromWorkList(N);
7023 return SDValue(N, 0); // Return N so it doesn't get rechecked!
7027 assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?");
7028 if (!N->hasAnyUseOfValue(0) && !N->hasAnyUseOfValue(1)) {
7029 SDValue Undef = DAG.getUNDEF(N->getValueType(0));
7030 DEBUG(dbgs() << "\nReplacing.7 ";
7032 dbgs() << "\nWith: ";
7033 Undef.getNode()->dump(&DAG);
7034 dbgs() << " and 2 other values\n");
7035 WorkListRemover DeadNodes(*this);
7036 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Undef);
7037 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1),
7038 DAG.getUNDEF(N->getValueType(1)));
7039 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 2), Chain);
7040 removeFromWorkList(N);
7042 return SDValue(N, 0); // Return N so it doesn't get rechecked!
7047 // If this load is directly stored, replace the load value with the stored
7049 // TODO: Handle store large -> read small portion.
7050 // TODO: Handle TRUNCSTORE/LOADEXT
7051 if (ISD::isNormalLoad(N) && !LD->isVolatile()) {
7052 if (ISD::isNON_TRUNCStore(Chain.getNode())) {
7053 StoreSDNode *PrevST = cast<StoreSDNode>(Chain);
7054 if (PrevST->getBasePtr() == Ptr &&
7055 PrevST->getValue().getValueType() == N->getValueType(0))
7056 return CombineTo(N, Chain.getOperand(1), Chain);
7060 // Try to infer better alignment information than the load already has.
7061 if (OptLevel != CodeGenOpt::None && LD->isUnindexed()) {
7062 if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
7063 if (Align > LD->getAlignment())
7064 return DAG.getExtLoad(LD->getExtensionType(), N->getDebugLoc(),
7065 LD->getValueType(0),
7066 Chain, Ptr, LD->getPointerInfo(),
7068 LD->isVolatile(), LD->isNonTemporal(), Align);
7073 // Walk up chain skipping non-aliasing memory nodes.
7074 SDValue BetterChain = FindBetterChain(N, Chain);
7076 // If there is a better chain.
7077 if (Chain != BetterChain) {
7080 // Replace the chain to void dependency.
7081 if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
7082 ReplLoad = DAG.getLoad(N->getValueType(0), LD->getDebugLoc(),
7083 BetterChain, Ptr, LD->getPointerInfo(),
7084 LD->isVolatile(), LD->isNonTemporal(),
7085 LD->isInvariant(), LD->getAlignment());
7087 ReplLoad = DAG.getExtLoad(LD->getExtensionType(), LD->getDebugLoc(),
7088 LD->getValueType(0),
7089 BetterChain, Ptr, LD->getPointerInfo(),
7092 LD->isNonTemporal(),
7093 LD->getAlignment());
7096 // Create token factor to keep old chain connected.
7097 SDValue Token = DAG.getNode(ISD::TokenFactor, N->getDebugLoc(),
7098 MVT::Other, Chain, ReplLoad.getValue(1));
7100 // Make sure the new and old chains are cleaned up.
7101 AddToWorkList(Token.getNode());
7103 // Replace uses with load result and token factor. Don't add users
7105 return CombineTo(N, ReplLoad.getValue(0), Token, false);
7109 // Try transforming N to an indexed load.
7110 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
7111 return SDValue(N, 0);
7116 /// CheckForMaskedLoad - Check to see if V is (and load (ptr), imm), where the
7117 /// load is having specific bytes cleared out. If so, return the byte size
7118 /// being masked out and the shift amount.
7119 static std::pair<unsigned, unsigned>
7120 CheckForMaskedLoad(SDValue V, SDValue Ptr, SDValue Chain) {
7121 std::pair<unsigned, unsigned> Result(0, 0);
7123 // Check for the structure we're looking for.
7124 if (V->getOpcode() != ISD::AND ||
7125 !isa<ConstantSDNode>(V->getOperand(1)) ||
7126 !ISD::isNormalLoad(V->getOperand(0).getNode()))
7129 // Check the chain and pointer.
7130 LoadSDNode *LD = cast<LoadSDNode>(V->getOperand(0));
7131 if (LD->getBasePtr() != Ptr) return Result; // Not from same pointer.
7133 // The store should be chained directly to the load or be an operand of a
7135 if (LD == Chain.getNode())
7137 else if (Chain->getOpcode() != ISD::TokenFactor)
7138 return Result; // Fail.
7141 for (unsigned i = 0, e = Chain->getNumOperands(); i != e; ++i)
7142 if (Chain->getOperand(i).getNode() == LD) {
7146 if (!isOk) return Result;
7149 // This only handles simple types.
7150 if (V.getValueType() != MVT::i16 &&
7151 V.getValueType() != MVT::i32 &&
7152 V.getValueType() != MVT::i64)
7155 // Check the constant mask. Invert it so that the bits being masked out are
7156 // 0 and the bits being kept are 1. Use getSExtValue so that leading bits
7157 // follow the sign bit for uniformity.
7158 uint64_t NotMask = ~cast<ConstantSDNode>(V->getOperand(1))->getSExtValue();
7159 unsigned NotMaskLZ = CountLeadingZeros_64(NotMask);
7160 if (NotMaskLZ & 7) return Result; // Must be multiple of a byte.
7161 unsigned NotMaskTZ = CountTrailingZeros_64(NotMask);
7162 if (NotMaskTZ & 7) return Result; // Must be multiple of a byte.
7163 if (NotMaskLZ == 64) return Result; // All zero mask.
7165 // See if we have a continuous run of bits. If so, we have 0*1+0*
7166 if (CountTrailingOnes_64(NotMask >> NotMaskTZ)+NotMaskTZ+NotMaskLZ != 64)
7169 // Adjust NotMaskLZ down to be from the actual size of the int instead of i64.
7170 if (V.getValueType() != MVT::i64 && NotMaskLZ)
7171 NotMaskLZ -= 64-V.getValueSizeInBits();
7173 unsigned MaskedBytes = (V.getValueSizeInBits()-NotMaskLZ-NotMaskTZ)/8;
7174 switch (MaskedBytes) {
7178 default: return Result; // All one mask, or 5-byte mask.
7181 // Verify that the first bit starts at a multiple of mask so that the access
7182 // is aligned the same as the access width.
7183 if (NotMaskTZ && NotMaskTZ/8 % MaskedBytes) return Result;
7185 Result.first = MaskedBytes;
7186 Result.second = NotMaskTZ/8;
7191 /// ShrinkLoadReplaceStoreWithStore - Check to see if IVal is something that
7192 /// provides a value as specified by MaskInfo. If so, replace the specified
7193 /// store with a narrower store of truncated IVal.
7195 ShrinkLoadReplaceStoreWithStore(const std::pair<unsigned, unsigned> &MaskInfo,
7196 SDValue IVal, StoreSDNode *St,
7198 unsigned NumBytes = MaskInfo.first;
7199 unsigned ByteShift = MaskInfo.second;
7200 SelectionDAG &DAG = DC->getDAG();
7202 // Check to see if IVal is all zeros in the part being masked in by the 'or'
7203 // that uses this. If not, this is not a replacement.
7204 APInt Mask = ~APInt::getBitsSet(IVal.getValueSizeInBits(),
7205 ByteShift*8, (ByteShift+NumBytes)*8);
7206 if (!DAG.MaskedValueIsZero(IVal, Mask)) return 0;
7208 // Check that it is legal on the target to do this. It is legal if the new
7209 // VT we're shrinking to (i8/i16/i32) is legal or we're still before type
7211 MVT VT = MVT::getIntegerVT(NumBytes*8);
7212 if (!DC->isTypeLegal(VT))
7215 // Okay, we can do this! Replace the 'St' store with a store of IVal that is
7216 // shifted by ByteShift and truncated down to NumBytes.
7218 IVal = DAG.getNode(ISD::SRL, IVal->getDebugLoc(), IVal.getValueType(), IVal,
7219 DAG.getConstant(ByteShift*8,
7220 DC->getShiftAmountTy(IVal.getValueType())));
7222 // Figure out the offset for the store and the alignment of the access.
7224 unsigned NewAlign = St->getAlignment();
7226 if (DAG.getTargetLoweringInfo().isLittleEndian())
7227 StOffset = ByteShift;
7229 StOffset = IVal.getValueType().getStoreSize() - ByteShift - NumBytes;
7231 SDValue Ptr = St->getBasePtr();
7233 Ptr = DAG.getNode(ISD::ADD, IVal->getDebugLoc(), Ptr.getValueType(),
7234 Ptr, DAG.getConstant(StOffset, Ptr.getValueType()));
7235 NewAlign = MinAlign(NewAlign, StOffset);
7238 // Truncate down to the new size.
7239 IVal = DAG.getNode(ISD::TRUNCATE, IVal->getDebugLoc(), VT, IVal);
7242 return DAG.getStore(St->getChain(), St->getDebugLoc(), IVal, Ptr,
7243 St->getPointerInfo().getWithOffset(StOffset),
7244 false, false, NewAlign).getNode();
7248 /// ReduceLoadOpStoreWidth - Look for sequence of load / op / store where op is
7249 /// one of 'or', 'xor', and 'and' of immediates. If 'op' is only touching some
7250 /// of the loaded bits, try narrowing the load and store if it would end up
7251 /// being a win for performance or code size.
7252 SDValue DAGCombiner::ReduceLoadOpStoreWidth(SDNode *N) {
7253 StoreSDNode *ST = cast<StoreSDNode>(N);
7254 if (ST->isVolatile())
7257 SDValue Chain = ST->getChain();
7258 SDValue Value = ST->getValue();
7259 SDValue Ptr = ST->getBasePtr();
7260 EVT VT = Value.getValueType();
7262 if (ST->isTruncatingStore() || VT.isVector() || !Value.hasOneUse())
7265 unsigned Opc = Value.getOpcode();
7267 // If this is "store (or X, Y), P" and X is "(and (load P), cst)", where cst
7268 // is a byte mask indicating a consecutive number of bytes, check to see if
7269 // Y is known to provide just those bytes. If so, we try to replace the
7270 // load + replace + store sequence with a single (narrower) store, which makes
7272 if (Opc == ISD::OR) {
7273 std::pair<unsigned, unsigned> MaskedLoad;
7274 MaskedLoad = CheckForMaskedLoad(Value.getOperand(0), Ptr, Chain);
7275 if (MaskedLoad.first)
7276 if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
7277 Value.getOperand(1), ST,this))
7278 return SDValue(NewST, 0);
7280 // Or is commutative, so try swapping X and Y.
7281 MaskedLoad = CheckForMaskedLoad(Value.getOperand(1), Ptr, Chain);
7282 if (MaskedLoad.first)
7283 if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
7284 Value.getOperand(0), ST,this))
7285 return SDValue(NewST, 0);
7288 if ((Opc != ISD::OR && Opc != ISD::XOR && Opc != ISD::AND) ||
7289 Value.getOperand(1).getOpcode() != ISD::Constant)
7292 SDValue N0 = Value.getOperand(0);
7293 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
7294 Chain == SDValue(N0.getNode(), 1)) {
7295 LoadSDNode *LD = cast<LoadSDNode>(N0);
7296 if (LD->getBasePtr() != Ptr ||
7297 LD->getPointerInfo().getAddrSpace() !=
7298 ST->getPointerInfo().getAddrSpace())
7301 // Find the type to narrow it the load / op / store to.
7302 SDValue N1 = Value.getOperand(1);
7303 unsigned BitWidth = N1.getValueSizeInBits();
7304 APInt Imm = cast<ConstantSDNode>(N1)->getAPIntValue();
7305 if (Opc == ISD::AND)
7306 Imm ^= APInt::getAllOnesValue(BitWidth);
7307 if (Imm == 0 || Imm.isAllOnesValue())
7309 unsigned ShAmt = Imm.countTrailingZeros();
7310 unsigned MSB = BitWidth - Imm.countLeadingZeros() - 1;
7311 unsigned NewBW = NextPowerOf2(MSB - ShAmt);
7312 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
7313 while (NewBW < BitWidth &&
7314 !(TLI.isOperationLegalOrCustom(Opc, NewVT) &&
7315 TLI.isNarrowingProfitable(VT, NewVT))) {
7316 NewBW = NextPowerOf2(NewBW);
7317 NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
7319 if (NewBW >= BitWidth)
7322 // If the lsb changed does not start at the type bitwidth boundary,
7323 // start at the previous one.
7325 ShAmt = (((ShAmt + NewBW - 1) / NewBW) * NewBW) - NewBW;
7326 APInt Mask = APInt::getBitsSet(BitWidth, ShAmt, ShAmt + NewBW);
7327 if ((Imm & Mask) == Imm) {
7328 APInt NewImm = (Imm & Mask).lshr(ShAmt).trunc(NewBW);
7329 if (Opc == ISD::AND)
7330 NewImm ^= APInt::getAllOnesValue(NewBW);
7331 uint64_t PtrOff = ShAmt / 8;
7332 // For big endian targets, we need to adjust the offset to the pointer to
7333 // load the correct bytes.
7334 if (TLI.isBigEndian())
7335 PtrOff = (BitWidth + 7 - NewBW) / 8 - PtrOff;
7337 unsigned NewAlign = MinAlign(LD->getAlignment(), PtrOff);
7338 Type *NewVTTy = NewVT.getTypeForEVT(*DAG.getContext());
7339 if (NewAlign < TLI.getTargetData()->getABITypeAlignment(NewVTTy))
7342 SDValue NewPtr = DAG.getNode(ISD::ADD, LD->getDebugLoc(),
7343 Ptr.getValueType(), Ptr,
7344 DAG.getConstant(PtrOff, Ptr.getValueType()));
7345 SDValue NewLD = DAG.getLoad(NewVT, N0.getDebugLoc(),
7346 LD->getChain(), NewPtr,
7347 LD->getPointerInfo().getWithOffset(PtrOff),
7348 LD->isVolatile(), LD->isNonTemporal(),
7349 LD->isInvariant(), NewAlign);
7350 SDValue NewVal = DAG.getNode(Opc, Value.getDebugLoc(), NewVT, NewLD,
7351 DAG.getConstant(NewImm, NewVT));
7352 SDValue NewST = DAG.getStore(Chain, N->getDebugLoc(),
7354 ST->getPointerInfo().getWithOffset(PtrOff),
7355 false, false, NewAlign);
7357 AddToWorkList(NewPtr.getNode());
7358 AddToWorkList(NewLD.getNode());
7359 AddToWorkList(NewVal.getNode());
7360 WorkListRemover DeadNodes(*this);
7361 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), NewLD.getValue(1));
7370 /// TransformFPLoadStorePair - For a given floating point load / store pair,
7371 /// if the load value isn't used by any other operations, then consider
7372 /// transforming the pair to integer load / store operations if the target
7373 /// deems the transformation profitable.
7374 SDValue DAGCombiner::TransformFPLoadStorePair(SDNode *N) {
7375 StoreSDNode *ST = cast<StoreSDNode>(N);
7376 SDValue Chain = ST->getChain();
7377 SDValue Value = ST->getValue();
7378 if (ISD::isNormalStore(ST) && ISD::isNormalLoad(Value.getNode()) &&
7379 Value.hasOneUse() &&
7380 Chain == SDValue(Value.getNode(), 1)) {
7381 LoadSDNode *LD = cast<LoadSDNode>(Value);
7382 EVT VT = LD->getMemoryVT();
7383 if (!VT.isFloatingPoint() ||
7384 VT != ST->getMemoryVT() ||
7385 LD->isNonTemporal() ||
7386 ST->isNonTemporal() ||
7387 LD->getPointerInfo().getAddrSpace() != 0 ||
7388 ST->getPointerInfo().getAddrSpace() != 0)
7391 EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits());
7392 if (!TLI.isOperationLegal(ISD::LOAD, IntVT) ||
7393 !TLI.isOperationLegal(ISD::STORE, IntVT) ||
7394 !TLI.isDesirableToTransformToIntegerOp(ISD::LOAD, VT) ||
7395 !TLI.isDesirableToTransformToIntegerOp(ISD::STORE, VT))
7398 unsigned LDAlign = LD->getAlignment();
7399 unsigned STAlign = ST->getAlignment();
7400 Type *IntVTTy = IntVT.getTypeForEVT(*DAG.getContext());
7401 unsigned ABIAlign = TLI.getTargetData()->getABITypeAlignment(IntVTTy);
7402 if (LDAlign < ABIAlign || STAlign < ABIAlign)
7405 SDValue NewLD = DAG.getLoad(IntVT, Value.getDebugLoc(),
7406 LD->getChain(), LD->getBasePtr(),
7407 LD->getPointerInfo(),
7408 false, false, false, LDAlign);
7410 SDValue NewST = DAG.getStore(NewLD.getValue(1), N->getDebugLoc(),
7411 NewLD, ST->getBasePtr(),
7412 ST->getPointerInfo(),
7413 false, false, STAlign);
7415 AddToWorkList(NewLD.getNode());
7416 AddToWorkList(NewST.getNode());
7417 WorkListRemover DeadNodes(*this);
7418 DAG.ReplaceAllUsesOfValueWith(Value.getValue(1), NewLD.getValue(1));
7426 SDValue DAGCombiner::visitSTORE(SDNode *N) {
7427 StoreSDNode *ST = cast<StoreSDNode>(N);
7428 SDValue Chain = ST->getChain();
7429 SDValue Value = ST->getValue();
7430 SDValue Ptr = ST->getBasePtr();
7432 // If this is a store of a bit convert, store the input value if the
7433 // resultant store does not need a higher alignment than the original.
7434 if (Value.getOpcode() == ISD::BITCAST && !ST->isTruncatingStore() &&
7435 ST->isUnindexed()) {
7436 unsigned OrigAlign = ST->getAlignment();
7437 EVT SVT = Value.getOperand(0).getValueType();
7438 unsigned Align = TLI.getTargetData()->
7439 getABITypeAlignment(SVT.getTypeForEVT(*DAG.getContext()));
7440 if (Align <= OrigAlign &&
7441 ((!LegalOperations && !ST->isVolatile()) ||
7442 TLI.isOperationLegalOrCustom(ISD::STORE, SVT)))
7443 return DAG.getStore(Chain, N->getDebugLoc(), Value.getOperand(0),
7444 Ptr, ST->getPointerInfo(), ST->isVolatile(),
7445 ST->isNonTemporal(), OrigAlign);
7448 // Turn 'store undef, Ptr' -> nothing.
7449 if (Value.getOpcode() == ISD::UNDEF && ST->isUnindexed())
7452 // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
7453 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Value)) {
7454 // NOTE: If the original store is volatile, this transform must not increase
7455 // the number of stores. For example, on x86-32 an f64 can be stored in one
7456 // processor operation but an i64 (which is not legal) requires two. So the
7457 // transform should not be done in this case.
7458 if (Value.getOpcode() != ISD::TargetConstantFP) {
7460 switch (CFP->getValueType(0).getSimpleVT().SimpleTy) {
7461 default: llvm_unreachable("Unknown FP type");
7462 case MVT::f16: // We don't do this for these yet.
7468 if ((isTypeLegal(MVT::i32) && !LegalOperations && !ST->isVolatile()) ||
7469 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
7470 Tmp = DAG.getConstant((uint32_t)CFP->getValueAPF().
7471 bitcastToAPInt().getZExtValue(), MVT::i32);
7472 return DAG.getStore(Chain, N->getDebugLoc(), Tmp,
7473 Ptr, ST->getPointerInfo(), ST->isVolatile(),
7474 ST->isNonTemporal(), ST->getAlignment());
7478 if ((TLI.isTypeLegal(MVT::i64) && !LegalOperations &&
7479 !ST->isVolatile()) ||
7480 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i64)) {
7481 Tmp = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
7482 getZExtValue(), MVT::i64);
7483 return DAG.getStore(Chain, N->getDebugLoc(), Tmp,
7484 Ptr, ST->getPointerInfo(), ST->isVolatile(),
7485 ST->isNonTemporal(), ST->getAlignment());
7488 if (!ST->isVolatile() &&
7489 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
7490 // Many FP stores are not made apparent until after legalize, e.g. for
7491 // argument passing. Since this is so common, custom legalize the
7492 // 64-bit integer store into two 32-bit stores.
7493 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
7494 SDValue Lo = DAG.getConstant(Val & 0xFFFFFFFF, MVT::i32);
7495 SDValue Hi = DAG.getConstant(Val >> 32, MVT::i32);
7496 if (TLI.isBigEndian()) std::swap(Lo, Hi);
7498 unsigned Alignment = ST->getAlignment();
7499 bool isVolatile = ST->isVolatile();
7500 bool isNonTemporal = ST->isNonTemporal();
7502 SDValue St0 = DAG.getStore(Chain, ST->getDebugLoc(), Lo,
7503 Ptr, ST->getPointerInfo(),
7504 isVolatile, isNonTemporal,
7505 ST->getAlignment());
7506 Ptr = DAG.getNode(ISD::ADD, N->getDebugLoc(), Ptr.getValueType(), Ptr,
7507 DAG.getConstant(4, Ptr.getValueType()));
7508 Alignment = MinAlign(Alignment, 4U);
7509 SDValue St1 = DAG.getStore(Chain, ST->getDebugLoc(), Hi,
7510 Ptr, ST->getPointerInfo().getWithOffset(4),
7511 isVolatile, isNonTemporal,
7513 return DAG.getNode(ISD::TokenFactor, N->getDebugLoc(), MVT::Other,
7522 // Try to infer better alignment information than the store already has.
7523 if (OptLevel != CodeGenOpt::None && ST->isUnindexed()) {
7524 if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
7525 if (Align > ST->getAlignment())
7526 return DAG.getTruncStore(Chain, N->getDebugLoc(), Value,
7527 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
7528 ST->isVolatile(), ST->isNonTemporal(), Align);
7532 // Try transforming a pair floating point load / store ops to integer
7533 // load / store ops.
7534 SDValue NewST = TransformFPLoadStorePair(N);
7535 if (NewST.getNode())
7539 // Walk up chain skipping non-aliasing memory nodes.
7540 SDValue BetterChain = FindBetterChain(N, Chain);
7542 // If there is a better chain.
7543 if (Chain != BetterChain) {
7546 // Replace the chain to avoid dependency.
7547 if (ST->isTruncatingStore()) {
7548 ReplStore = DAG.getTruncStore(BetterChain, N->getDebugLoc(), Value, Ptr,
7549 ST->getPointerInfo(),
7550 ST->getMemoryVT(), ST->isVolatile(),
7551 ST->isNonTemporal(), ST->getAlignment());
7553 ReplStore = DAG.getStore(BetterChain, N->getDebugLoc(), Value, Ptr,
7554 ST->getPointerInfo(),
7555 ST->isVolatile(), ST->isNonTemporal(),
7556 ST->getAlignment());
7559 // Create token to keep both nodes around.
7560 SDValue Token = DAG.getNode(ISD::TokenFactor, N->getDebugLoc(),
7561 MVT::Other, Chain, ReplStore);
7563 // Make sure the new and old chains are cleaned up.
7564 AddToWorkList(Token.getNode());
7566 // Don't add users to work list.
7567 return CombineTo(N, Token, false);
7571 // Try transforming N to an indexed store.
7572 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
7573 return SDValue(N, 0);
7575 // FIXME: is there such a thing as a truncating indexed store?
7576 if (ST->isTruncatingStore() && ST->isUnindexed() &&
7577 Value.getValueType().isInteger()) {
7578 // See if we can simplify the input to this truncstore with knowledge that
7579 // only the low bits are being used. For example:
7580 // "truncstore (or (shl x, 8), y), i8" -> "truncstore y, i8"
7582 GetDemandedBits(Value,
7583 APInt::getLowBitsSet(
7584 Value.getValueType().getScalarType().getSizeInBits(),
7585 ST->getMemoryVT().getScalarType().getSizeInBits()));
7586 AddToWorkList(Value.getNode());
7587 if (Shorter.getNode())
7588 return DAG.getTruncStore(Chain, N->getDebugLoc(), Shorter,
7589 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
7590 ST->isVolatile(), ST->isNonTemporal(),
7591 ST->getAlignment());
7593 // Otherwise, see if we can simplify the operation with
7594 // SimplifyDemandedBits, which only works if the value has a single use.
7595 if (SimplifyDemandedBits(Value,
7596 APInt::getLowBitsSet(
7597 Value.getValueType().getScalarType().getSizeInBits(),
7598 ST->getMemoryVT().getScalarType().getSizeInBits())))
7599 return SDValue(N, 0);
7602 // If this is a load followed by a store to the same location, then the store
7604 if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Value)) {
7605 if (Ld->getBasePtr() == Ptr && ST->getMemoryVT() == Ld->getMemoryVT() &&
7606 ST->isUnindexed() && !ST->isVolatile() &&
7607 // There can't be any side effects between the load and store, such as
7609 Chain.reachesChainWithoutSideEffects(SDValue(Ld, 1))) {
7610 // The store is dead, remove it.
7615 // If this is an FP_ROUND or TRUNC followed by a store, fold this into a
7616 // truncating store. We can do this even if this is already a truncstore.
7617 if ((Value.getOpcode() == ISD::FP_ROUND || Value.getOpcode() == ISD::TRUNCATE)
7618 && Value.getNode()->hasOneUse() && ST->isUnindexed() &&
7619 TLI.isTruncStoreLegal(Value.getOperand(0).getValueType(),
7620 ST->getMemoryVT())) {
7621 return DAG.getTruncStore(Chain, N->getDebugLoc(), Value.getOperand(0),
7622 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
7623 ST->isVolatile(), ST->isNonTemporal(),
7624 ST->getAlignment());
7627 return ReduceLoadOpStoreWidth(N);
7630 SDValue DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) {
7631 SDValue InVec = N->getOperand(0);
7632 SDValue InVal = N->getOperand(1);
7633 SDValue EltNo = N->getOperand(2);
7634 DebugLoc dl = N->getDebugLoc();
7636 // If the inserted element is an UNDEF, just use the input vector.
7637 if (InVal.getOpcode() == ISD::UNDEF)
7640 EVT VT = InVec.getValueType();
7642 // If we can't generate a legal BUILD_VECTOR, exit
7643 if (LegalOperations && !TLI.isOperationLegal(ISD::BUILD_VECTOR, VT))
7646 // Check that we know which element is being inserted
7647 if (!isa<ConstantSDNode>(EltNo))
7649 unsigned Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
7651 // Check that the operand is a BUILD_VECTOR (or UNDEF, which can essentially
7652 // be converted to a BUILD_VECTOR). Fill in the Ops vector with the
7654 SmallVector<SDValue, 8> Ops;
7655 if (InVec.getOpcode() == ISD::BUILD_VECTOR) {
7656 Ops.append(InVec.getNode()->op_begin(),
7657 InVec.getNode()->op_end());
7658 } else if (InVec.getOpcode() == ISD::UNDEF) {
7659 unsigned NElts = VT.getVectorNumElements();
7660 Ops.append(NElts, DAG.getUNDEF(InVal.getValueType()));
7665 // Insert the element
7666 if (Elt < Ops.size()) {
7667 // All the operands of BUILD_VECTOR must have the same type;
7668 // we enforce that here.
7669 EVT OpVT = Ops[0].getValueType();
7670 if (InVal.getValueType() != OpVT)
7671 InVal = OpVT.bitsGT(InVal.getValueType()) ?
7672 DAG.getNode(ISD::ANY_EXTEND, dl, OpVT, InVal) :
7673 DAG.getNode(ISD::TRUNCATE, dl, OpVT, InVal);
7677 // Return the new vector
7678 return DAG.getNode(ISD::BUILD_VECTOR, dl,
7679 VT, &Ops[0], Ops.size());
7682 SDValue DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) {
7683 // (vextract (scalar_to_vector val, 0) -> val
7684 SDValue InVec = N->getOperand(0);
7685 EVT VT = InVec.getValueType();
7686 EVT NVT = N->getValueType(0);
7688 if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR) {
7689 // Check if the result type doesn't match the inserted element type. A
7690 // SCALAR_TO_VECTOR may truncate the inserted element and the
7691 // EXTRACT_VECTOR_ELT may widen the extracted vector.
7692 SDValue InOp = InVec.getOperand(0);
7693 if (InOp.getValueType() != NVT) {
7694 assert(InOp.getValueType().isInteger() && NVT.isInteger());
7695 return DAG.getSExtOrTrunc(InOp, InVec.getDebugLoc(), NVT);
7700 SDValue EltNo = N->getOperand(1);
7701 bool ConstEltNo = isa<ConstantSDNode>(EltNo);
7703 // Transform: (EXTRACT_VECTOR_ELT( VECTOR_SHUFFLE )) -> EXTRACT_VECTOR_ELT.
7704 // We only perform this optimization before the op legalization phase because
7705 // we may introduce new vector instructions which are not backed by TD
7706 // patterns. For example on AVX, extracting elements from a wide vector
7707 // without using extract_subvector.
7708 if (InVec.getOpcode() == ISD::VECTOR_SHUFFLE
7709 && ConstEltNo && !LegalOperations) {
7710 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
7711 int NumElem = VT.getVectorNumElements();
7712 ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(InVec);
7713 // Find the new index to extract from.
7714 int OrigElt = SVOp->getMaskElt(Elt);
7716 // Extracting an undef index is undef.
7718 return DAG.getUNDEF(NVT);
7720 // Select the right vector half to extract from.
7721 if (OrigElt < NumElem) {
7722 InVec = InVec->getOperand(0);
7724 InVec = InVec->getOperand(1);
7728 EVT IndexTy = N->getOperand(1).getValueType();
7729 return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, N->getDebugLoc(), NVT,
7730 InVec, DAG.getConstant(OrigElt, IndexTy));
7733 // Perform only after legalization to ensure build_vector / vector_shuffle
7734 // optimizations have already been done.
7735 if (!LegalOperations) return SDValue();
7737 // (vextract (v4f32 load $addr), c) -> (f32 load $addr+c*size)
7738 // (vextract (v4f32 s2v (f32 load $addr)), c) -> (f32 load $addr+c*size)
7739 // (vextract (v4f32 shuffle (load $addr), <1,u,u,u>), 0) -> (f32 load $addr)
7742 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
7743 bool NewLoad = false;
7744 bool BCNumEltsChanged = false;
7745 EVT ExtVT = VT.getVectorElementType();
7748 // If the result of load has to be truncated, then it's not necessarily
7750 if (NVT.bitsLT(LVT) && !TLI.isTruncateFree(LVT, NVT))
7753 if (InVec.getOpcode() == ISD::BITCAST) {
7754 // Don't duplicate a load with other uses.
7755 if (!InVec.hasOneUse())
7758 EVT BCVT = InVec.getOperand(0).getValueType();
7759 if (!BCVT.isVector() || ExtVT.bitsGT(BCVT.getVectorElementType()))
7761 if (VT.getVectorNumElements() != BCVT.getVectorNumElements())
7762 BCNumEltsChanged = true;
7763 InVec = InVec.getOperand(0);
7764 ExtVT = BCVT.getVectorElementType();
7768 LoadSDNode *LN0 = NULL;
7769 const ShuffleVectorSDNode *SVN = NULL;
7770 if (ISD::isNormalLoad(InVec.getNode())) {
7771 LN0 = cast<LoadSDNode>(InVec);
7772 } else if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR &&
7773 InVec.getOperand(0).getValueType() == ExtVT &&
7774 ISD::isNormalLoad(InVec.getOperand(0).getNode())) {
7775 // Don't duplicate a load with other uses.
7776 if (!InVec.hasOneUse())
7779 LN0 = cast<LoadSDNode>(InVec.getOperand(0));
7780 } else if ((SVN = dyn_cast<ShuffleVectorSDNode>(InVec))) {
7781 // (vextract (vector_shuffle (load $addr), v2, <1, u, u, u>), 1)
7783 // (load $addr+1*size)
7785 // Don't duplicate a load with other uses.
7786 if (!InVec.hasOneUse())
7789 // If the bit convert changed the number of elements, it is unsafe
7790 // to examine the mask.
7791 if (BCNumEltsChanged)
7794 // Select the input vector, guarding against out of range extract vector.
7795 unsigned NumElems = VT.getVectorNumElements();
7796 int Idx = (Elt > (int)NumElems) ? -1 : SVN->getMaskElt(Elt);
7797 InVec = (Idx < (int)NumElems) ? InVec.getOperand(0) : InVec.getOperand(1);
7799 if (InVec.getOpcode() == ISD::BITCAST) {
7800 // Don't duplicate a load with other uses.
7801 if (!InVec.hasOneUse())
7804 InVec = InVec.getOperand(0);
7806 if (ISD::isNormalLoad(InVec.getNode())) {
7807 LN0 = cast<LoadSDNode>(InVec);
7808 Elt = (Idx < (int)NumElems) ? Idx : Idx - (int)NumElems;
7812 // Make sure we found a non-volatile load and the extractelement is
7814 if (!LN0 || !LN0->hasNUsesOfValue(1,0) || LN0->isVolatile())
7817 // If Idx was -1 above, Elt is going to be -1, so just return undef.
7819 return DAG.getUNDEF(LVT);
7821 unsigned Align = LN0->getAlignment();
7823 // Check the resultant load doesn't need a higher alignment than the
7827 ->getABITypeAlignment(LVT.getTypeForEVT(*DAG.getContext()));
7829 if (NewAlign > Align || !TLI.isOperationLegalOrCustom(ISD::LOAD, LVT))
7835 SDValue NewPtr = LN0->getBasePtr();
7836 unsigned PtrOff = 0;
7839 PtrOff = LVT.getSizeInBits() * Elt / 8;
7840 EVT PtrType = NewPtr.getValueType();
7841 if (TLI.isBigEndian())
7842 PtrOff = VT.getSizeInBits() / 8 - PtrOff;
7843 NewPtr = DAG.getNode(ISD::ADD, N->getDebugLoc(), PtrType, NewPtr,
7844 DAG.getConstant(PtrOff, PtrType));
7847 // The replacement we need to do here is a little tricky: we need to
7848 // replace an extractelement of a load with a load.
7849 // Use ReplaceAllUsesOfValuesWith to do the replacement.
7850 // Note that this replacement assumes that the extractvalue is the only
7851 // use of the load; that's okay because we don't want to perform this
7852 // transformation in other cases anyway.
7855 if (NVT.bitsGT(LVT)) {
7856 // If the result type of vextract is wider than the load, then issue an
7857 // extending load instead.
7858 ISD::LoadExtType ExtType = TLI.isLoadExtLegal(ISD::ZEXTLOAD, LVT)
7859 ? ISD::ZEXTLOAD : ISD::EXTLOAD;
7860 Load = DAG.getExtLoad(ExtType, N->getDebugLoc(), NVT, LN0->getChain(),
7861 NewPtr, LN0->getPointerInfo().getWithOffset(PtrOff),
7862 LVT, LN0->isVolatile(), LN0->isNonTemporal(),Align);
7863 Chain = Load.getValue(1);
7865 Load = DAG.getLoad(LVT, N->getDebugLoc(), LN0->getChain(), NewPtr,
7866 LN0->getPointerInfo().getWithOffset(PtrOff),
7867 LN0->isVolatile(), LN0->isNonTemporal(),
7868 LN0->isInvariant(), Align);
7869 Chain = Load.getValue(1);
7870 if (NVT.bitsLT(LVT))
7871 Load = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), NVT, Load);
7873 Load = DAG.getNode(ISD::BITCAST, N->getDebugLoc(), NVT, Load);
7875 WorkListRemover DeadNodes(*this);
7876 SDValue From[] = { SDValue(N, 0), SDValue(LN0,1) };
7877 SDValue To[] = { Load, Chain };
7878 DAG.ReplaceAllUsesOfValuesWith(From, To, 2);
7879 // Since we're explcitly calling ReplaceAllUses, add the new node to the
7880 // worklist explicitly as well.
7881 AddToWorkList(Load.getNode());
7882 AddUsersToWorkList(Load.getNode()); // Add users too
7883 // Make sure to revisit this node to clean it up; it will usually be dead.
7885 return SDValue(N, 0);
7891 SDValue DAGCombiner::visitBUILD_VECTOR(SDNode *N) {
7892 unsigned NumInScalars = N->getNumOperands();
7893 DebugLoc dl = N->getDebugLoc();
7894 EVT VT = N->getValueType(0);
7896 // A vector built entirely of undefs is undef.
7897 if (ISD::allOperandsUndef(N))
7898 return DAG.getUNDEF(VT);
7900 // Check to see if this is a BUILD_VECTOR of a bunch of values
7901 // which come from any_extend or zero_extend nodes. If so, we can create
7902 // a new BUILD_VECTOR using bit-casts which may enable other BUILD_VECTOR
7903 // optimizations. We do not handle sign-extend because we can't fill the sign
7905 EVT SourceType = MVT::Other;
7906 bool AllAnyExt = true;
7908 for (unsigned i = 0; i != NumInScalars; ++i) {
7909 SDValue In = N->getOperand(i);
7910 // Ignore undef inputs.
7911 if (In.getOpcode() == ISD::UNDEF) continue;
7913 bool AnyExt = In.getOpcode() == ISD::ANY_EXTEND;
7914 bool ZeroExt = In.getOpcode() == ISD::ZERO_EXTEND;
7916 // Abort if the element is not an extension.
7917 if (!ZeroExt && !AnyExt) {
7918 SourceType = MVT::Other;
7922 // The input is a ZeroExt or AnyExt. Check the original type.
7923 EVT InTy = In.getOperand(0).getValueType();
7925 // Check that all of the widened source types are the same.
7926 if (SourceType == MVT::Other)
7929 else if (InTy != SourceType) {
7930 // Multiple income types. Abort.
7931 SourceType = MVT::Other;
7935 // Check if all of the extends are ANY_EXTENDs.
7936 AllAnyExt &= AnyExt;
7939 // In order to have valid types, all of the inputs must be extended from the
7940 // same source type and all of the inputs must be any or zero extend.
7941 // Scalar sizes must be a power of two.
7942 EVT OutScalarTy = N->getValueType(0).getScalarType();
7943 bool ValidTypes = SourceType != MVT::Other &&
7944 isPowerOf2_32(OutScalarTy.getSizeInBits()) &&
7945 isPowerOf2_32(SourceType.getSizeInBits());
7947 // We perform this optimization post type-legalization because
7948 // the type-legalizer often scalarizes integer-promoted vectors.
7949 // Performing this optimization before may create bit-casts which
7950 // will be type-legalized to complex code sequences.
7951 // We perform this optimization only before the operation legalizer because we
7952 // may introduce illegal operations.
7953 // Create a new simpler BUILD_VECTOR sequence which other optimizations can
7954 // turn into a single shuffle instruction.
7955 if ((Level == AfterLegalizeVectorOps || Level == AfterLegalizeTypes) &&
7957 bool isLE = TLI.isLittleEndian();
7958 unsigned ElemRatio = OutScalarTy.getSizeInBits()/SourceType.getSizeInBits();
7959 assert(ElemRatio > 1 && "Invalid element size ratio");
7960 SDValue Filler = AllAnyExt ? DAG.getUNDEF(SourceType):
7961 DAG.getConstant(0, SourceType);
7963 unsigned NewBVElems = ElemRatio * N->getValueType(0).getVectorNumElements();
7964 SmallVector<SDValue, 8> Ops(NewBVElems, Filler);
7966 // Populate the new build_vector
7967 for (unsigned i=0; i < N->getNumOperands(); ++i) {
7968 SDValue Cast = N->getOperand(i);
7969 assert((Cast.getOpcode() == ISD::ANY_EXTEND ||
7970 Cast.getOpcode() == ISD::ZERO_EXTEND ||
7971 Cast.getOpcode() == ISD::UNDEF) && "Invalid cast opcode");
7973 if (Cast.getOpcode() == ISD::UNDEF)
7974 In = DAG.getUNDEF(SourceType);
7976 In = Cast->getOperand(0);
7977 unsigned Index = isLE ? (i * ElemRatio) :
7978 (i * ElemRatio + (ElemRatio - 1));
7980 assert(Index < Ops.size() && "Invalid index");
7984 // The type of the new BUILD_VECTOR node.
7985 EVT VecVT = EVT::getVectorVT(*DAG.getContext(), SourceType, NewBVElems);
7986 assert(VecVT.getSizeInBits() == N->getValueType(0).getSizeInBits() &&
7987 "Invalid vector size");
7988 // Check if the new vector type is legal.
7989 if (!isTypeLegal(VecVT)) return SDValue();
7991 // Make the new BUILD_VECTOR.
7992 SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(),
7993 VecVT, &Ops[0], Ops.size());
7995 // The new BUILD_VECTOR node has the potential to be further optimized.
7996 AddToWorkList(BV.getNode());
7997 // Bitcast to the desired type.
7998 return DAG.getNode(ISD::BITCAST, dl, N->getValueType(0), BV);
8001 // Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT
8002 // operations. If so, and if the EXTRACT_VECTOR_ELT vector inputs come from
8003 // at most two distinct vectors, turn this into a shuffle node.
8005 // May only combine to shuffle after legalize if shuffle is legal.
8006 if (LegalOperations &&
8007 !TLI.isOperationLegalOrCustom(ISD::VECTOR_SHUFFLE, VT))
8010 SDValue VecIn1, VecIn2;
8011 for (unsigned i = 0; i != NumInScalars; ++i) {
8012 // Ignore undef inputs.
8013 if (N->getOperand(i).getOpcode() == ISD::UNDEF) continue;
8015 // If this input is something other than a EXTRACT_VECTOR_ELT with a
8016 // constant index, bail out.
8017 if (N->getOperand(i).getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
8018 !isa<ConstantSDNode>(N->getOperand(i).getOperand(1))) {
8019 VecIn1 = VecIn2 = SDValue(0, 0);
8023 // We allow up to two distinct input vectors.
8024 SDValue ExtractedFromVec = N->getOperand(i).getOperand(0);
8025 if (ExtractedFromVec == VecIn1 || ExtractedFromVec == VecIn2)
8028 if (VecIn1.getNode() == 0) {
8029 VecIn1 = ExtractedFromVec;
8030 } else if (VecIn2.getNode() == 0) {
8031 VecIn2 = ExtractedFromVec;
8034 VecIn1 = VecIn2 = SDValue(0, 0);
8039 // If everything is good, we can make a shuffle operation.
8040 if (VecIn1.getNode()) {
8041 SmallVector<int, 8> Mask;
8042 for (unsigned i = 0; i != NumInScalars; ++i) {
8043 if (N->getOperand(i).getOpcode() == ISD::UNDEF) {
8048 // If extracting from the first vector, just use the index directly.
8049 SDValue Extract = N->getOperand(i);
8050 SDValue ExtVal = Extract.getOperand(1);
8051 if (Extract.getOperand(0) == VecIn1) {
8052 unsigned ExtIndex = cast<ConstantSDNode>(ExtVal)->getZExtValue();
8053 if (ExtIndex > VT.getVectorNumElements())
8056 Mask.push_back(ExtIndex);
8060 // Otherwise, use InIdx + VecSize
8061 unsigned Idx = cast<ConstantSDNode>(ExtVal)->getZExtValue();
8062 Mask.push_back(Idx+NumInScalars);
8065 // We can't generate a shuffle node with mismatched input and output types.
8066 // Attempt to transform a single input vector to the correct type.
8067 if ((VT != VecIn1.getValueType())) {
8068 // We don't support shuffeling between TWO values of different types.
8069 if (VecIn2.getNode() != 0)
8072 // We only support widening of vectors which are half the size of the
8073 // output registers. For example XMM->YMM widening on X86 with AVX.
8074 if (VecIn1.getValueType().getSizeInBits()*2 != VT.getSizeInBits())
8077 // If the input vector type has a different base type to the output
8078 // vector type, bail out.
8079 if (VecIn1.getValueType().getVectorElementType() !=
8080 VT.getVectorElementType())
8083 // Widen the input vector by adding undef values.
8084 VecIn1 = DAG.getNode(ISD::CONCAT_VECTORS, N->getDebugLoc(), VT,
8085 VecIn1, DAG.getUNDEF(VecIn1.getValueType()));
8088 // If VecIn2 is unused then change it to undef.
8089 VecIn2 = VecIn2.getNode() ? VecIn2 : DAG.getUNDEF(VT);
8091 // Check that we were able to transform all incoming values to the same
8093 if (VecIn2.getValueType() != VecIn1.getValueType() ||
8094 VecIn1.getValueType() != VT)
8097 // Only type-legal BUILD_VECTOR nodes are converted to shuffle nodes.
8098 if (!isTypeLegal(VT))
8101 // Return the new VECTOR_SHUFFLE node.
8105 return DAG.getVectorShuffle(VT, N->getDebugLoc(), Ops[0], Ops[1], &Mask[0]);
8111 SDValue DAGCombiner::visitCONCAT_VECTORS(SDNode *N) {
8112 // TODO: Check to see if this is a CONCAT_VECTORS of a bunch of
8113 // EXTRACT_SUBVECTOR operations. If so, and if the EXTRACT_SUBVECTOR vector
8114 // inputs come from at most two distinct vectors, turn this into a shuffle
8117 // If we only have one input vector, we don't need to do any concatenation.
8118 if (N->getNumOperands() == 1)
8119 return N->getOperand(0);
8121 // Check if all of the operands are undefs.
8122 if (ISD::allOperandsUndef(N))
8123 return DAG.getUNDEF(N->getValueType(0));
8128 SDValue DAGCombiner::visitEXTRACT_SUBVECTOR(SDNode* N) {
8129 EVT NVT = N->getValueType(0);
8130 SDValue V = N->getOperand(0);
8132 if (V->getOpcode() == ISD::INSERT_SUBVECTOR) {
8133 // Handle only simple case where vector being inserted and vector
8134 // being extracted are of same type, and are half size of larger vectors.
8135 EVT BigVT = V->getOperand(0).getValueType();
8136 EVT SmallVT = V->getOperand(1).getValueType();
8137 if (NVT != SmallVT || NVT.getSizeInBits()*2 != BigVT.getSizeInBits())
8140 // Only handle cases where both indexes are constants with the same type.
8141 ConstantSDNode *InsIdx = dyn_cast<ConstantSDNode>(N->getOperand(1));
8142 ConstantSDNode *ExtIdx = dyn_cast<ConstantSDNode>(V->getOperand(2));
8144 if (InsIdx && ExtIdx &&
8145 InsIdx->getValueType(0).getSizeInBits() <= 64 &&
8146 ExtIdx->getValueType(0).getSizeInBits() <= 64) {
8148 // (extract_subvec (insert_subvec V1, V2, InsIdx), ExtIdx)
8150 // indices are equal => V1
8151 // otherwise => (extract_subvec V1, ExtIdx)
8152 if (InsIdx->getZExtValue() == ExtIdx->getZExtValue())
8153 return V->getOperand(1);
8154 return DAG.getNode(ISD::EXTRACT_SUBVECTOR, N->getDebugLoc(), NVT,
8155 V->getOperand(0), N->getOperand(1));
8162 SDValue DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
8163 EVT VT = N->getValueType(0);
8164 unsigned NumElts = VT.getVectorNumElements();
8166 SDValue N0 = N->getOperand(0);
8167 SDValue N1 = N->getOperand(1);
8169 assert(N0.getValueType() == VT && "Vector shuffle must be normalized in DAG");
8171 // Canonicalize shuffle undef, undef -> undef
8172 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
8173 return DAG.getUNDEF(VT);
8175 ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
8177 // Canonicalize shuffle v, v -> v, undef
8179 SmallVector<int, 8> NewMask;
8180 for (unsigned i = 0; i != NumElts; ++i) {
8181 int Idx = SVN->getMaskElt(i);
8182 if (Idx >= (int)NumElts) Idx -= NumElts;
8183 NewMask.push_back(Idx);
8185 return DAG.getVectorShuffle(VT, N->getDebugLoc(), N0, DAG.getUNDEF(VT),
8189 // Canonicalize shuffle undef, v -> v, undef. Commute the shuffle mask.
8190 if (N0.getOpcode() == ISD::UNDEF) {
8191 SmallVector<int, 8> NewMask;
8192 for (unsigned i = 0; i != NumElts; ++i) {
8193 int Idx = SVN->getMaskElt(i);
8195 if (Idx < (int)NumElts)
8200 NewMask.push_back(Idx);
8202 return DAG.getVectorShuffle(VT, N->getDebugLoc(), N1, DAG.getUNDEF(VT),
8206 // Remove references to rhs if it is undef
8207 if (N1.getOpcode() == ISD::UNDEF) {
8208 bool Changed = false;
8209 SmallVector<int, 8> NewMask;
8210 for (unsigned i = 0; i != NumElts; ++i) {
8211 int Idx = SVN->getMaskElt(i);
8212 if (Idx >= (int)NumElts) {
8216 NewMask.push_back(Idx);
8219 return DAG.getVectorShuffle(VT, N->getDebugLoc(), N0, N1, &NewMask[0]);
8222 // If it is a splat, check if the argument vector is another splat or a
8223 // build_vector with all scalar elements the same.
8224 if (SVN->isSplat() && SVN->getSplatIndex() < (int)NumElts) {
8225 SDNode *V = N0.getNode();
8227 // If this is a bit convert that changes the element type of the vector but
8228 // not the number of vector elements, look through it. Be careful not to
8229 // look though conversions that change things like v4f32 to v2f64.
8230 if (V->getOpcode() == ISD::BITCAST) {
8231 SDValue ConvInput = V->getOperand(0);
8232 if (ConvInput.getValueType().isVector() &&
8233 ConvInput.getValueType().getVectorNumElements() == NumElts)
8234 V = ConvInput.getNode();
8237 if (V->getOpcode() == ISD::BUILD_VECTOR) {
8238 assert(V->getNumOperands() == NumElts &&
8239 "BUILD_VECTOR has wrong number of operands");
8241 bool AllSame = true;
8242 for (unsigned i = 0; i != NumElts; ++i) {
8243 if (V->getOperand(i).getOpcode() != ISD::UNDEF) {
8244 Base = V->getOperand(i);
8248 // Splat of <u, u, u, u>, return <u, u, u, u>
8249 if (!Base.getNode())
8251 for (unsigned i = 0; i != NumElts; ++i) {
8252 if (V->getOperand(i) != Base) {
8257 // Splat of <x, x, x, x>, return <x, x, x, x>
8263 // If this shuffle node is simply a swizzle of another shuffle node,
8264 // and it reverses the swizzle of the previous shuffle then we can
8265 // optimize shuffle(shuffle(x, undef), undef) -> x.
8266 if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
8267 N1.getOpcode() == ISD::UNDEF) {
8269 ShuffleVectorSDNode *OtherSV = cast<ShuffleVectorSDNode>(N0);
8271 // Shuffle nodes can only reverse shuffles with a single non-undef value.
8272 if (N0.getOperand(1).getOpcode() != ISD::UNDEF)
8275 // The incoming shuffle must be of the same type as the result of the
8277 assert(OtherSV->getOperand(0).getValueType() == VT &&
8278 "Shuffle types don't match");
8280 for (unsigned i = 0; i != NumElts; ++i) {
8281 int Idx = SVN->getMaskElt(i);
8282 assert(Idx < (int)NumElts && "Index references undef operand");
8283 // Next, this index comes from the first value, which is the incoming
8284 // shuffle. Adopt the incoming index.
8286 Idx = OtherSV->getMaskElt(Idx);
8288 // The combined shuffle must map each index to itself.
8289 if (Idx >= 0 && (unsigned)Idx != i)
8293 return OtherSV->getOperand(0);
8299 SDValue DAGCombiner::visitMEMBARRIER(SDNode* N) {
8300 if (!TLI.getShouldFoldAtomicFences())
8303 SDValue atomic = N->getOperand(0);
8304 switch (atomic.getOpcode()) {
8305 case ISD::ATOMIC_CMP_SWAP:
8306 case ISD::ATOMIC_SWAP:
8307 case ISD::ATOMIC_LOAD_ADD:
8308 case ISD::ATOMIC_LOAD_SUB:
8309 case ISD::ATOMIC_LOAD_AND:
8310 case ISD::ATOMIC_LOAD_OR:
8311 case ISD::ATOMIC_LOAD_XOR:
8312 case ISD::ATOMIC_LOAD_NAND:
8313 case ISD::ATOMIC_LOAD_MIN:
8314 case ISD::ATOMIC_LOAD_MAX:
8315 case ISD::ATOMIC_LOAD_UMIN:
8316 case ISD::ATOMIC_LOAD_UMAX:
8322 SDValue fence = atomic.getOperand(0);
8323 if (fence.getOpcode() != ISD::MEMBARRIER)
8326 switch (atomic.getOpcode()) {
8327 case ISD::ATOMIC_CMP_SWAP:
8328 return SDValue(DAG.UpdateNodeOperands(atomic.getNode(),
8329 fence.getOperand(0),
8330 atomic.getOperand(1), atomic.getOperand(2),
8331 atomic.getOperand(3)), atomic.getResNo());
8332 case ISD::ATOMIC_SWAP:
8333 case ISD::ATOMIC_LOAD_ADD:
8334 case ISD::ATOMIC_LOAD_SUB:
8335 case ISD::ATOMIC_LOAD_AND:
8336 case ISD::ATOMIC_LOAD_OR:
8337 case ISD::ATOMIC_LOAD_XOR:
8338 case ISD::ATOMIC_LOAD_NAND:
8339 case ISD::ATOMIC_LOAD_MIN:
8340 case ISD::ATOMIC_LOAD_MAX:
8341 case ISD::ATOMIC_LOAD_UMIN:
8342 case ISD::ATOMIC_LOAD_UMAX:
8343 return SDValue(DAG.UpdateNodeOperands(atomic.getNode(),
8344 fence.getOperand(0),
8345 atomic.getOperand(1), atomic.getOperand(2)),
8352 /// XformToShuffleWithZero - Returns a vector_shuffle if it able to transform
8353 /// an AND to a vector_shuffle with the destination vector and a zero vector.
8354 /// e.g. AND V, <0xffffffff, 0, 0xffffffff, 0>. ==>
8355 /// vector_shuffle V, Zero, <0, 4, 2, 4>
8356 SDValue DAGCombiner::XformToShuffleWithZero(SDNode *N) {
8357 EVT VT = N->getValueType(0);
8358 DebugLoc dl = N->getDebugLoc();
8359 SDValue LHS = N->getOperand(0);
8360 SDValue RHS = N->getOperand(1);
8361 if (N->getOpcode() == ISD::AND) {
8362 if (RHS.getOpcode() == ISD::BITCAST)
8363 RHS = RHS.getOperand(0);
8364 if (RHS.getOpcode() == ISD::BUILD_VECTOR) {
8365 SmallVector<int, 8> Indices;
8366 unsigned NumElts = RHS.getNumOperands();
8367 for (unsigned i = 0; i != NumElts; ++i) {
8368 SDValue Elt = RHS.getOperand(i);
8369 if (!isa<ConstantSDNode>(Elt))
8372 if (cast<ConstantSDNode>(Elt)->isAllOnesValue())
8373 Indices.push_back(i);
8374 else if (cast<ConstantSDNode>(Elt)->isNullValue())
8375 Indices.push_back(NumElts);
8380 // Let's see if the target supports this vector_shuffle.
8381 EVT RVT = RHS.getValueType();
8382 if (!TLI.isVectorClearMaskLegal(Indices, RVT))
8385 // Return the new VECTOR_SHUFFLE node.
8386 EVT EltVT = RVT.getVectorElementType();
8387 SmallVector<SDValue,8> ZeroOps(RVT.getVectorNumElements(),
8388 DAG.getConstant(0, EltVT));
8389 SDValue Zero = DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(),
8390 RVT, &ZeroOps[0], ZeroOps.size());
8391 LHS = DAG.getNode(ISD::BITCAST, dl, RVT, LHS);
8392 SDValue Shuf = DAG.getVectorShuffle(RVT, dl, LHS, Zero, &Indices[0]);
8393 return DAG.getNode(ISD::BITCAST, dl, VT, Shuf);
8400 /// SimplifyVBinOp - Visit a binary vector operation, like ADD.
8401 SDValue DAGCombiner::SimplifyVBinOp(SDNode *N) {
8402 // After legalize, the target may be depending on adds and other
8403 // binary ops to provide legal ways to construct constants or other
8404 // things. Simplifying them may result in a loss of legality.
8405 if (LegalOperations) return SDValue();
8407 assert(N->getValueType(0).isVector() &&
8408 "SimplifyVBinOp only works on vectors!");
8410 SDValue LHS = N->getOperand(0);
8411 SDValue RHS = N->getOperand(1);
8412 SDValue Shuffle = XformToShuffleWithZero(N);
8413 if (Shuffle.getNode()) return Shuffle;
8415 // If the LHS and RHS are BUILD_VECTOR nodes, see if we can constant fold
8417 if (LHS.getOpcode() == ISD::BUILD_VECTOR &&
8418 RHS.getOpcode() == ISD::BUILD_VECTOR) {
8419 SmallVector<SDValue, 8> Ops;
8420 for (unsigned i = 0, e = LHS.getNumOperands(); i != e; ++i) {
8421 SDValue LHSOp = LHS.getOperand(i);
8422 SDValue RHSOp = RHS.getOperand(i);
8423 // If these two elements can't be folded, bail out.
8424 if ((LHSOp.getOpcode() != ISD::UNDEF &&
8425 LHSOp.getOpcode() != ISD::Constant &&
8426 LHSOp.getOpcode() != ISD::ConstantFP) ||
8427 (RHSOp.getOpcode() != ISD::UNDEF &&
8428 RHSOp.getOpcode() != ISD::Constant &&
8429 RHSOp.getOpcode() != ISD::ConstantFP))
8432 // Can't fold divide by zero.
8433 if (N->getOpcode() == ISD::SDIV || N->getOpcode() == ISD::UDIV ||
8434 N->getOpcode() == ISD::FDIV) {
8435 if ((RHSOp.getOpcode() == ISD::Constant &&
8436 cast<ConstantSDNode>(RHSOp.getNode())->isNullValue()) ||
8437 (RHSOp.getOpcode() == ISD::ConstantFP &&
8438 cast<ConstantFPSDNode>(RHSOp.getNode())->getValueAPF().isZero()))
8442 EVT VT = LHSOp.getValueType();
8443 EVT RVT = RHSOp.getValueType();
8445 // Integer BUILD_VECTOR operands may have types larger than the element
8446 // size (e.g., when the element type is not legal). Prior to type
8447 // legalization, the types may not match between the two BUILD_VECTORS.
8448 // Truncate one of the operands to make them match.
8449 if (RVT.getSizeInBits() > VT.getSizeInBits()) {
8450 RHSOp = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, RHSOp);
8452 LHSOp = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), RVT, LHSOp);
8456 SDValue FoldOp = DAG.getNode(N->getOpcode(), LHS.getDebugLoc(), VT,
8458 if (FoldOp.getOpcode() != ISD::UNDEF &&
8459 FoldOp.getOpcode() != ISD::Constant &&
8460 FoldOp.getOpcode() != ISD::ConstantFP)
8462 Ops.push_back(FoldOp);
8463 AddToWorkList(FoldOp.getNode());
8466 if (Ops.size() == LHS.getNumOperands())
8467 return DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(),
8468 LHS.getValueType(), &Ops[0], Ops.size());
8474 /// SimplifyVUnaryOp - Visit a binary vector operation, like FABS/FNEG.
8475 SDValue DAGCombiner::SimplifyVUnaryOp(SDNode *N) {
8476 // After legalize, the target may be depending on adds and other
8477 // binary ops to provide legal ways to construct constants or other
8478 // things. Simplifying them may result in a loss of legality.
8479 if (LegalOperations) return SDValue();
8481 assert(N->getValueType(0).isVector() &&
8482 "SimplifyVUnaryOp only works on vectors!");
8484 SDValue N0 = N->getOperand(0);
8486 if (N0.getOpcode() != ISD::BUILD_VECTOR)
8489 // Operand is a BUILD_VECTOR node, see if we can constant fold it.
8490 SmallVector<SDValue, 8> Ops;
8491 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i) {
8492 SDValue Op = N0.getOperand(i);
8493 if (Op.getOpcode() != ISD::UNDEF &&
8494 Op.getOpcode() != ISD::ConstantFP)
8496 EVT EltVT = Op.getValueType();
8497 SDValue FoldOp = DAG.getNode(N->getOpcode(), N0.getDebugLoc(), EltVT, Op);
8498 if (FoldOp.getOpcode() != ISD::UNDEF &&
8499 FoldOp.getOpcode() != ISD::ConstantFP)
8501 Ops.push_back(FoldOp);
8502 AddToWorkList(FoldOp.getNode());
8505 if (Ops.size() != N0.getNumOperands())
8508 return DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(),
8509 N0.getValueType(), &Ops[0], Ops.size());
8512 SDValue DAGCombiner::SimplifySelect(DebugLoc DL, SDValue N0,
8513 SDValue N1, SDValue N2){
8514 assert(N0.getOpcode() ==ISD::SETCC && "First argument must be a SetCC node!");
8516 SDValue SCC = SimplifySelectCC(DL, N0.getOperand(0), N0.getOperand(1), N1, N2,
8517 cast<CondCodeSDNode>(N0.getOperand(2))->get());
8519 // If we got a simplified select_cc node back from SimplifySelectCC, then
8520 // break it down into a new SETCC node, and a new SELECT node, and then return
8521 // the SELECT node, since we were called with a SELECT node.
8522 if (SCC.getNode()) {
8523 // Check to see if we got a select_cc back (to turn into setcc/select).
8524 // Otherwise, just return whatever node we got back, like fabs.
8525 if (SCC.getOpcode() == ISD::SELECT_CC) {
8526 SDValue SETCC = DAG.getNode(ISD::SETCC, N0.getDebugLoc(),
8528 SCC.getOperand(0), SCC.getOperand(1),
8530 AddToWorkList(SETCC.getNode());
8531 return DAG.getNode(ISD::SELECT, SCC.getDebugLoc(), SCC.getValueType(),
8532 SCC.getOperand(2), SCC.getOperand(3), SETCC);
8540 /// SimplifySelectOps - Given a SELECT or a SELECT_CC node, where LHS and RHS
8541 /// are the two values being selected between, see if we can simplify the
8542 /// select. Callers of this should assume that TheSelect is deleted if this
8543 /// returns true. As such, they should return the appropriate thing (e.g. the
8544 /// node) back to the top-level of the DAG combiner loop to avoid it being
8546 bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS,
8549 // Cannot simplify select with vector condition
8550 if (TheSelect->getOperand(0).getValueType().isVector()) return false;
8552 // If this is a select from two identical things, try to pull the operation
8553 // through the select.
8554 if (LHS.getOpcode() != RHS.getOpcode() ||
8555 !LHS.hasOneUse() || !RHS.hasOneUse())
8558 // If this is a load and the token chain is identical, replace the select
8559 // of two loads with a load through a select of the address to load from.
8560 // This triggers in things like "select bool X, 10.0, 123.0" after the FP
8561 // constants have been dropped into the constant pool.
8562 if (LHS.getOpcode() == ISD::LOAD) {
8563 LoadSDNode *LLD = cast<LoadSDNode>(LHS);
8564 LoadSDNode *RLD = cast<LoadSDNode>(RHS);
8566 // Token chains must be identical.
8567 if (LHS.getOperand(0) != RHS.getOperand(0) ||
8568 // Do not let this transformation reduce the number of volatile loads.
8569 LLD->isVolatile() || RLD->isVolatile() ||
8570 // If this is an EXTLOAD, the VT's must match.
8571 LLD->getMemoryVT() != RLD->getMemoryVT() ||
8572 // If this is an EXTLOAD, the kind of extension must match.
8573 (LLD->getExtensionType() != RLD->getExtensionType() &&
8574 // The only exception is if one of the extensions is anyext.
8575 LLD->getExtensionType() != ISD::EXTLOAD &&
8576 RLD->getExtensionType() != ISD::EXTLOAD) ||
8577 // FIXME: this discards src value information. This is
8578 // over-conservative. It would be beneficial to be able to remember
8579 // both potential memory locations. Since we are discarding
8580 // src value info, don't do the transformation if the memory
8581 // locations are not in the default address space.
8582 LLD->getPointerInfo().getAddrSpace() != 0 ||
8583 RLD->getPointerInfo().getAddrSpace() != 0)
8586 // Check that the select condition doesn't reach either load. If so,
8587 // folding this will induce a cycle into the DAG. If not, this is safe to
8588 // xform, so create a select of the addresses.
8590 if (TheSelect->getOpcode() == ISD::SELECT) {
8591 SDNode *CondNode = TheSelect->getOperand(0).getNode();
8592 if ((LLD->hasAnyUseOfValue(1) && LLD->isPredecessorOf(CondNode)) ||
8593 (RLD->hasAnyUseOfValue(1) && RLD->isPredecessorOf(CondNode)))
8595 Addr = DAG.getNode(ISD::SELECT, TheSelect->getDebugLoc(),
8596 LLD->getBasePtr().getValueType(),
8597 TheSelect->getOperand(0), LLD->getBasePtr(),
8599 } else { // Otherwise SELECT_CC
8600 SDNode *CondLHS = TheSelect->getOperand(0).getNode();
8601 SDNode *CondRHS = TheSelect->getOperand(1).getNode();
8603 if ((LLD->hasAnyUseOfValue(1) &&
8604 (LLD->isPredecessorOf(CondLHS) || LLD->isPredecessorOf(CondRHS))) ||
8605 (RLD->hasAnyUseOfValue(1) &&
8606 (RLD->isPredecessorOf(CondLHS) || RLD->isPredecessorOf(CondRHS))))
8609 Addr = DAG.getNode(ISD::SELECT_CC, TheSelect->getDebugLoc(),
8610 LLD->getBasePtr().getValueType(),
8611 TheSelect->getOperand(0),
8612 TheSelect->getOperand(1),
8613 LLD->getBasePtr(), RLD->getBasePtr(),
8614 TheSelect->getOperand(4));
8618 if (LLD->getExtensionType() == ISD::NON_EXTLOAD) {
8619 Load = DAG.getLoad(TheSelect->getValueType(0),
8620 TheSelect->getDebugLoc(),
8621 // FIXME: Discards pointer info.
8622 LLD->getChain(), Addr, MachinePointerInfo(),
8623 LLD->isVolatile(), LLD->isNonTemporal(),
8624 LLD->isInvariant(), LLD->getAlignment());
8626 Load = DAG.getExtLoad(LLD->getExtensionType() == ISD::EXTLOAD ?
8627 RLD->getExtensionType() : LLD->getExtensionType(),
8628 TheSelect->getDebugLoc(),
8629 TheSelect->getValueType(0),
8630 // FIXME: Discards pointer info.
8631 LLD->getChain(), Addr, MachinePointerInfo(),
8632 LLD->getMemoryVT(), LLD->isVolatile(),
8633 LLD->isNonTemporal(), LLD->getAlignment());
8636 // Users of the select now use the result of the load.
8637 CombineTo(TheSelect, Load);
8639 // Users of the old loads now use the new load's chain. We know the
8640 // old-load value is dead now.
8641 CombineTo(LHS.getNode(), Load.getValue(0), Load.getValue(1));
8642 CombineTo(RHS.getNode(), Load.getValue(0), Load.getValue(1));
8649 /// SimplifySelectCC - Simplify an expression of the form (N0 cond N1) ? N2 : N3
8650 /// where 'cond' is the comparison specified by CC.
8651 SDValue DAGCombiner::SimplifySelectCC(DebugLoc DL, SDValue N0, SDValue N1,
8652 SDValue N2, SDValue N3,
8653 ISD::CondCode CC, bool NotExtCompare) {
8654 // (x ? y : y) -> y.
8655 if (N2 == N3) return N2;
8657 EVT VT = N2.getValueType();
8658 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
8659 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.getNode());
8660 ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N3.getNode());
8662 // Determine if the condition we're dealing with is constant
8663 SDValue SCC = SimplifySetCC(TLI.getSetCCResultType(N0.getValueType()),
8664 N0, N1, CC, DL, false);
8665 if (SCC.getNode()) AddToWorkList(SCC.getNode());
8666 ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.getNode());
8668 // fold select_cc true, x, y -> x
8669 if (SCCC && !SCCC->isNullValue())
8671 // fold select_cc false, x, y -> y
8672 if (SCCC && SCCC->isNullValue())
8675 // Check to see if we can simplify the select into an fabs node
8676 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1)) {
8677 // Allow either -0.0 or 0.0
8678 if (CFP->getValueAPF().isZero()) {
8679 // select (setg[te] X, +/-0.0), X, fneg(X) -> fabs
8680 if ((CC == ISD::SETGE || CC == ISD::SETGT) &&
8681 N0 == N2 && N3.getOpcode() == ISD::FNEG &&
8682 N2 == N3.getOperand(0))
8683 return DAG.getNode(ISD::FABS, DL, VT, N0);
8685 // select (setl[te] X, +/-0.0), fneg(X), X -> fabs
8686 if ((CC == ISD::SETLT || CC == ISD::SETLE) &&
8687 N0 == N3 && N2.getOpcode() == ISD::FNEG &&
8688 N2.getOperand(0) == N3)
8689 return DAG.getNode(ISD::FABS, DL, VT, N3);
8693 // Turn "(a cond b) ? 1.0f : 2.0f" into "load (tmp + ((a cond b) ? 0 : 4)"
8694 // where "tmp" is a constant pool entry containing an array with 1.0 and 2.0
8695 // in it. This is a win when the constant is not otherwise available because
8696 // it replaces two constant pool loads with one. We only do this if the FP
8697 // type is known to be legal, because if it isn't, then we are before legalize
8698 // types an we want the other legalization to happen first (e.g. to avoid
8699 // messing with soft float) and if the ConstantFP is not legal, because if
8700 // it is legal, we may not need to store the FP constant in a constant pool.
8701 if (ConstantFPSDNode *TV = dyn_cast<ConstantFPSDNode>(N2))
8702 if (ConstantFPSDNode *FV = dyn_cast<ConstantFPSDNode>(N3)) {
8703 if (TLI.isTypeLegal(N2.getValueType()) &&
8704 (TLI.getOperationAction(ISD::ConstantFP, N2.getValueType()) !=
8705 TargetLowering::Legal) &&
8706 // If both constants have multiple uses, then we won't need to do an
8707 // extra load, they are likely around in registers for other users.
8708 (TV->hasOneUse() || FV->hasOneUse())) {
8709 Constant *Elts[] = {
8710 const_cast<ConstantFP*>(FV->getConstantFPValue()),
8711 const_cast<ConstantFP*>(TV->getConstantFPValue())
8713 Type *FPTy = Elts[0]->getType();
8714 const TargetData &TD = *TLI.getTargetData();
8716 // Create a ConstantArray of the two constants.
8717 Constant *CA = ConstantArray::get(ArrayType::get(FPTy, 2), Elts);
8718 SDValue CPIdx = DAG.getConstantPool(CA, TLI.getPointerTy(),
8719 TD.getPrefTypeAlignment(FPTy));
8720 unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
8722 // Get the offsets to the 0 and 1 element of the array so that we can
8723 // select between them.
8724 SDValue Zero = DAG.getIntPtrConstant(0);
8725 unsigned EltSize = (unsigned)TD.getTypeAllocSize(Elts[0]->getType());
8726 SDValue One = DAG.getIntPtrConstant(EltSize);
8728 SDValue Cond = DAG.getSetCC(DL,
8729 TLI.getSetCCResultType(N0.getValueType()),
8731 AddToWorkList(Cond.getNode());
8732 SDValue CstOffset = DAG.getNode(ISD::SELECT, DL, Zero.getValueType(),
8734 AddToWorkList(CstOffset.getNode());
8735 CPIdx = DAG.getNode(ISD::ADD, DL, TLI.getPointerTy(), CPIdx,
8737 AddToWorkList(CPIdx.getNode());
8738 return DAG.getLoad(TV->getValueType(0), DL, DAG.getEntryNode(), CPIdx,
8739 MachinePointerInfo::getConstantPool(), false,
8740 false, false, Alignment);
8745 // Check to see if we can perform the "gzip trick", transforming
8746 // (select_cc setlt X, 0, A, 0) -> (and (sra X, (sub size(X), 1), A)
8747 if (N1C && N3C && N3C->isNullValue() && CC == ISD::SETLT &&
8748 (N1C->isNullValue() || // (a < 0) ? b : 0
8749 (N1C->getAPIntValue() == 1 && N0 == N2))) { // (a < 1) ? a : 0
8750 EVT XType = N0.getValueType();
8751 EVT AType = N2.getValueType();
8752 if (XType.bitsGE(AType)) {
8753 // and (sra X, size(X)-1, A) -> "and (srl X, C2), A" iff A is a
8754 // single-bit constant.
8755 if (N2C && ((N2C->getAPIntValue() & (N2C->getAPIntValue()-1)) == 0)) {
8756 unsigned ShCtV = N2C->getAPIntValue().logBase2();
8757 ShCtV = XType.getSizeInBits()-ShCtV-1;
8758 SDValue ShCt = DAG.getConstant(ShCtV,
8759 getShiftAmountTy(N0.getValueType()));
8760 SDValue Shift = DAG.getNode(ISD::SRL, N0.getDebugLoc(),
8762 AddToWorkList(Shift.getNode());
8764 if (XType.bitsGT(AType)) {
8765 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
8766 AddToWorkList(Shift.getNode());
8769 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
8772 SDValue Shift = DAG.getNode(ISD::SRA, N0.getDebugLoc(),
8774 DAG.getConstant(XType.getSizeInBits()-1,
8775 getShiftAmountTy(N0.getValueType())));
8776 AddToWorkList(Shift.getNode());
8778 if (XType.bitsGT(AType)) {
8779 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
8780 AddToWorkList(Shift.getNode());
8783 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
8787 // fold (select_cc seteq (and x, y), 0, 0, A) -> (and (shr (shl x)) A)
8788 // where y is has a single bit set.
8789 // A plaintext description would be, we can turn the SELECT_CC into an AND
8790 // when the condition can be materialized as an all-ones register. Any
8791 // single bit-test can be materialized as an all-ones register with
8792 // shift-left and shift-right-arith.
8793 if (CC == ISD::SETEQ && N0->getOpcode() == ISD::AND &&
8794 N0->getValueType(0) == VT &&
8795 N1C && N1C->isNullValue() &&
8796 N2C && N2C->isNullValue()) {
8797 SDValue AndLHS = N0->getOperand(0);
8798 ConstantSDNode *ConstAndRHS = dyn_cast<ConstantSDNode>(N0->getOperand(1));
8799 if (ConstAndRHS && ConstAndRHS->getAPIntValue().countPopulation() == 1) {
8800 // Shift the tested bit over the sign bit.
8801 APInt AndMask = ConstAndRHS->getAPIntValue();
8803 DAG.getConstant(AndMask.countLeadingZeros(),
8804 getShiftAmountTy(AndLHS.getValueType()));
8805 SDValue Shl = DAG.getNode(ISD::SHL, N0.getDebugLoc(), VT, AndLHS, ShlAmt);
8807 // Now arithmetic right shift it all the way over, so the result is either
8808 // all-ones, or zero.
8810 DAG.getConstant(AndMask.getBitWidth()-1,
8811 getShiftAmountTy(Shl.getValueType()));
8812 SDValue Shr = DAG.getNode(ISD::SRA, N0.getDebugLoc(), VT, Shl, ShrAmt);
8814 return DAG.getNode(ISD::AND, DL, VT, Shr, N3);
8818 // fold select C, 16, 0 -> shl C, 4
8819 if (N2C && N3C && N3C->isNullValue() && N2C->getAPIntValue().isPowerOf2() &&
8820 TLI.getBooleanContents(N0.getValueType().isVector()) ==
8821 TargetLowering::ZeroOrOneBooleanContent) {
8823 // If the caller doesn't want us to simplify this into a zext of a compare,
8825 if (NotExtCompare && N2C->getAPIntValue() == 1)
8828 // Get a SetCC of the condition
8829 // FIXME: Should probably make sure that setcc is legal if we ever have a
8830 // target where it isn't.
8832 // cast from setcc result type to select result type
8834 SCC = DAG.getSetCC(DL, TLI.getSetCCResultType(N0.getValueType()),
8836 if (N2.getValueType().bitsLT(SCC.getValueType()))
8837 Temp = DAG.getZeroExtendInReg(SCC, N2.getDebugLoc(), N2.getValueType());
8839 Temp = DAG.getNode(ISD::ZERO_EXTEND, N2.getDebugLoc(),
8840 N2.getValueType(), SCC);
8842 SCC = DAG.getSetCC(N0.getDebugLoc(), MVT::i1, N0, N1, CC);
8843 Temp = DAG.getNode(ISD::ZERO_EXTEND, N2.getDebugLoc(),
8844 N2.getValueType(), SCC);
8847 AddToWorkList(SCC.getNode());
8848 AddToWorkList(Temp.getNode());
8850 if (N2C->getAPIntValue() == 1)
8853 // shl setcc result by log2 n2c
8854 return DAG.getNode(ISD::SHL, DL, N2.getValueType(), Temp,
8855 DAG.getConstant(N2C->getAPIntValue().logBase2(),
8856 getShiftAmountTy(Temp.getValueType())));
8859 // Check to see if this is the equivalent of setcc
8860 // FIXME: Turn all of these into setcc if setcc if setcc is legal
8861 // otherwise, go ahead with the folds.
8862 if (0 && N3C && N3C->isNullValue() && N2C && (N2C->getAPIntValue() == 1ULL)) {
8863 EVT XType = N0.getValueType();
8864 if (!LegalOperations ||
8865 TLI.isOperationLegal(ISD::SETCC, TLI.getSetCCResultType(XType))) {
8866 SDValue Res = DAG.getSetCC(DL, TLI.getSetCCResultType(XType), N0, N1, CC);
8867 if (Res.getValueType() != VT)
8868 Res = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Res);
8872 // fold (seteq X, 0) -> (srl (ctlz X, log2(size(X))))
8873 if (N1C && N1C->isNullValue() && CC == ISD::SETEQ &&
8874 (!LegalOperations ||
8875 TLI.isOperationLegal(ISD::CTLZ, XType))) {
8876 SDValue Ctlz = DAG.getNode(ISD::CTLZ, N0.getDebugLoc(), XType, N0);
8877 return DAG.getNode(ISD::SRL, DL, XType, Ctlz,
8878 DAG.getConstant(Log2_32(XType.getSizeInBits()),
8879 getShiftAmountTy(Ctlz.getValueType())));
8881 // fold (setgt X, 0) -> (srl (and (-X, ~X), size(X)-1))
8882 if (N1C && N1C->isNullValue() && CC == ISD::SETGT) {
8883 SDValue NegN0 = DAG.getNode(ISD::SUB, N0.getDebugLoc(),
8884 XType, DAG.getConstant(0, XType), N0);
8885 SDValue NotN0 = DAG.getNOT(N0.getDebugLoc(), N0, XType);
8886 return DAG.getNode(ISD::SRL, DL, XType,
8887 DAG.getNode(ISD::AND, DL, XType, NegN0, NotN0),
8888 DAG.getConstant(XType.getSizeInBits()-1,
8889 getShiftAmountTy(XType)));
8891 // fold (setgt X, -1) -> (xor (srl (X, size(X)-1), 1))
8892 if (N1C && N1C->isAllOnesValue() && CC == ISD::SETGT) {
8893 SDValue Sign = DAG.getNode(ISD::SRL, N0.getDebugLoc(), XType, N0,
8894 DAG.getConstant(XType.getSizeInBits()-1,
8895 getShiftAmountTy(N0.getValueType())));
8896 return DAG.getNode(ISD::XOR, DL, XType, Sign, DAG.getConstant(1, XType));
8900 // Check to see if this is an integer abs.
8901 // select_cc setg[te] X, 0, X, -X ->
8902 // select_cc setgt X, -1, X, -X ->
8903 // select_cc setl[te] X, 0, -X, X ->
8904 // select_cc setlt X, 1, -X, X ->
8905 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
8907 ConstantSDNode *SubC = NULL;
8908 if (((N1C->isNullValue() && (CC == ISD::SETGT || CC == ISD::SETGE)) ||
8909 (N1C->isAllOnesValue() && CC == ISD::SETGT)) &&
8910 N0 == N2 && N3.getOpcode() == ISD::SUB && N0 == N3.getOperand(1))
8911 SubC = dyn_cast<ConstantSDNode>(N3.getOperand(0));
8912 else if (((N1C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE)) ||
8913 (N1C->isOne() && CC == ISD::SETLT)) &&
8914 N0 == N3 && N2.getOpcode() == ISD::SUB && N0 == N2.getOperand(1))
8915 SubC = dyn_cast<ConstantSDNode>(N2.getOperand(0));
8917 EVT XType = N0.getValueType();
8918 if (SubC && SubC->isNullValue() && XType.isInteger()) {
8919 SDValue Shift = DAG.getNode(ISD::SRA, N0.getDebugLoc(), XType,
8921 DAG.getConstant(XType.getSizeInBits()-1,
8922 getShiftAmountTy(N0.getValueType())));
8923 SDValue Add = DAG.getNode(ISD::ADD, N0.getDebugLoc(),
8925 AddToWorkList(Shift.getNode());
8926 AddToWorkList(Add.getNode());
8927 return DAG.getNode(ISD::XOR, DL, XType, Add, Shift);
8934 /// SimplifySetCC - This is a stub for TargetLowering::SimplifySetCC.
8935 SDValue DAGCombiner::SimplifySetCC(EVT VT, SDValue N0,
8936 SDValue N1, ISD::CondCode Cond,
8937 DebugLoc DL, bool foldBooleans) {
8938 TargetLowering::DAGCombinerInfo
8939 DagCombineInfo(DAG, !LegalTypes, !LegalOperations, false, this);
8940 return TLI.SimplifySetCC(VT, N0, N1, Cond, foldBooleans, DagCombineInfo, DL);
8943 /// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
8944 /// return a DAG expression to select that will generate the same value by
8945 /// multiplying by a magic number. See:
8946 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
8947 SDValue DAGCombiner::BuildSDIV(SDNode *N) {
8948 std::vector<SDNode*> Built;
8949 SDValue S = TLI.BuildSDIV(N, DAG, LegalOperations, &Built);
8951 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
8957 /// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant,
8958 /// return a DAG expression to select that will generate the same value by
8959 /// multiplying by a magic number. See:
8960 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
8961 SDValue DAGCombiner::BuildUDIV(SDNode *N) {
8962 std::vector<SDNode*> Built;
8963 SDValue S = TLI.BuildUDIV(N, DAG, LegalOperations, &Built);
8965 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
8971 /// FindBaseOffset - Return true if base is a frame index, which is known not
8972 // to alias with anything but itself. Provides base object and offset as
8974 static bool FindBaseOffset(SDValue Ptr, SDValue &Base, int64_t &Offset,
8975 const GlobalValue *&GV, const void *&CV) {
8976 // Assume it is a primitive operation.
8977 Base = Ptr; Offset = 0; GV = 0; CV = 0;
8979 // If it's an adding a simple constant then integrate the offset.
8980 if (Base.getOpcode() == ISD::ADD) {
8981 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Base.getOperand(1))) {
8982 Base = Base.getOperand(0);
8983 Offset += C->getZExtValue();
8987 // Return the underlying GlobalValue, and update the Offset. Return false
8988 // for GlobalAddressSDNode since the same GlobalAddress may be represented
8989 // by multiple nodes with different offsets.
8990 if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Base)) {
8991 GV = G->getGlobal();
8992 Offset += G->getOffset();
8996 // Return the underlying Constant value, and update the Offset. Return false
8997 // for ConstantSDNodes since the same constant pool entry may be represented
8998 // by multiple nodes with different offsets.
8999 if (ConstantPoolSDNode *C = dyn_cast<ConstantPoolSDNode>(Base)) {
9000 CV = C->isMachineConstantPoolEntry() ? (const void *)C->getMachineCPVal()
9001 : (const void *)C->getConstVal();
9002 Offset += C->getOffset();
9005 // If it's any of the following then it can't alias with anything but itself.
9006 return isa<FrameIndexSDNode>(Base);
9009 /// isAlias - Return true if there is any possibility that the two addresses
9011 bool DAGCombiner::isAlias(SDValue Ptr1, int64_t Size1,
9012 const Value *SrcValue1, int SrcValueOffset1,
9013 unsigned SrcValueAlign1,
9014 const MDNode *TBAAInfo1,
9015 SDValue Ptr2, int64_t Size2,
9016 const Value *SrcValue2, int SrcValueOffset2,
9017 unsigned SrcValueAlign2,
9018 const MDNode *TBAAInfo2) const {
9019 // If they are the same then they must be aliases.
9020 if (Ptr1 == Ptr2) return true;
9022 // Gather base node and offset information.
9023 SDValue Base1, Base2;
9024 int64_t Offset1, Offset2;
9025 const GlobalValue *GV1, *GV2;
9026 const void *CV1, *CV2;
9027 bool isFrameIndex1 = FindBaseOffset(Ptr1, Base1, Offset1, GV1, CV1);
9028 bool isFrameIndex2 = FindBaseOffset(Ptr2, Base2, Offset2, GV2, CV2);
9030 // If they have a same base address then check to see if they overlap.
9031 if (Base1 == Base2 || (GV1 && (GV1 == GV2)) || (CV1 && (CV1 == CV2)))
9032 return !((Offset1 + Size1) <= Offset2 || (Offset2 + Size2) <= Offset1);
9034 // It is possible for different frame indices to alias each other, mostly
9035 // when tail call optimization reuses return address slots for arguments.
9036 // To catch this case, look up the actual index of frame indices to compute
9037 // the real alias relationship.
9038 if (isFrameIndex1 && isFrameIndex2) {
9039 MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
9040 Offset1 += MFI->getObjectOffset(cast<FrameIndexSDNode>(Base1)->getIndex());
9041 Offset2 += MFI->getObjectOffset(cast<FrameIndexSDNode>(Base2)->getIndex());
9042 return !((Offset1 + Size1) <= Offset2 || (Offset2 + Size2) <= Offset1);
9045 // Otherwise, if we know what the bases are, and they aren't identical, then
9046 // we know they cannot alias.
9047 if ((isFrameIndex1 || CV1 || GV1) && (isFrameIndex2 || CV2 || GV2))
9050 // If we know required SrcValue1 and SrcValue2 have relatively large alignment
9051 // compared to the size and offset of the access, we may be able to prove they
9052 // do not alias. This check is conservative for now to catch cases created by
9053 // splitting vector types.
9054 if ((SrcValueAlign1 == SrcValueAlign2) &&
9055 (SrcValueOffset1 != SrcValueOffset2) &&
9056 (Size1 == Size2) && (SrcValueAlign1 > Size1)) {
9057 int64_t OffAlign1 = SrcValueOffset1 % SrcValueAlign1;
9058 int64_t OffAlign2 = SrcValueOffset2 % SrcValueAlign1;
9060 // There is no overlap between these relatively aligned accesses of similar
9061 // size, return no alias.
9062 if ((OffAlign1 + Size1) <= OffAlign2 || (OffAlign2 + Size2) <= OffAlign1)
9066 if (CombinerGlobalAA) {
9067 // Use alias analysis information.
9068 int64_t MinOffset = std::min(SrcValueOffset1, SrcValueOffset2);
9069 int64_t Overlap1 = Size1 + SrcValueOffset1 - MinOffset;
9070 int64_t Overlap2 = Size2 + SrcValueOffset2 - MinOffset;
9071 AliasAnalysis::AliasResult AAResult =
9072 AA.alias(AliasAnalysis::Location(SrcValue1, Overlap1, TBAAInfo1),
9073 AliasAnalysis::Location(SrcValue2, Overlap2, TBAAInfo2));
9074 if (AAResult == AliasAnalysis::NoAlias)
9078 // Otherwise we have to assume they alias.
9082 /// FindAliasInfo - Extracts the relevant alias information from the memory
9083 /// node. Returns true if the operand was a load.
9084 bool DAGCombiner::FindAliasInfo(SDNode *N,
9085 SDValue &Ptr, int64_t &Size,
9086 const Value *&SrcValue,
9087 int &SrcValueOffset,
9088 unsigned &SrcValueAlign,
9089 const MDNode *&TBAAInfo) const {
9090 LSBaseSDNode *LS = cast<LSBaseSDNode>(N);
9092 Ptr = LS->getBasePtr();
9093 Size = LS->getMemoryVT().getSizeInBits() >> 3;
9094 SrcValue = LS->getSrcValue();
9095 SrcValueOffset = LS->getSrcValueOffset();
9096 SrcValueAlign = LS->getOriginalAlignment();
9097 TBAAInfo = LS->getTBAAInfo();
9098 return isa<LoadSDNode>(LS);
9101 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
9102 /// looking for aliasing nodes and adding them to the Aliases vector.
9103 void DAGCombiner::GatherAllAliases(SDNode *N, SDValue OriginalChain,
9104 SmallVector<SDValue, 8> &Aliases) {
9105 SmallVector<SDValue, 8> Chains; // List of chains to visit.
9106 SmallPtrSet<SDNode *, 16> Visited; // Visited node set.
9108 // Get alias information for node.
9111 const Value *SrcValue;
9113 unsigned SrcValueAlign;
9114 const MDNode *SrcTBAAInfo;
9115 bool IsLoad = FindAliasInfo(N, Ptr, Size, SrcValue, SrcValueOffset,
9116 SrcValueAlign, SrcTBAAInfo);
9119 Chains.push_back(OriginalChain);
9122 // Look at each chain and determine if it is an alias. If so, add it to the
9123 // aliases list. If not, then continue up the chain looking for the next
9125 while (!Chains.empty()) {
9126 SDValue Chain = Chains.back();
9129 // For TokenFactor nodes, look at each operand and only continue up the
9130 // chain until we find two aliases. If we've seen two aliases, assume we'll
9131 // find more and revert to original chain since the xform is unlikely to be
9134 // FIXME: The depth check could be made to return the last non-aliasing
9135 // chain we found before we hit a tokenfactor rather than the original
9137 if (Depth > 6 || Aliases.size() == 2) {
9139 Aliases.push_back(OriginalChain);
9143 // Don't bother if we've been before.
9144 if (!Visited.insert(Chain.getNode()))
9147 switch (Chain.getOpcode()) {
9148 case ISD::EntryToken:
9149 // Entry token is ideal chain operand, but handled in FindBetterChain.
9154 // Get alias information for Chain.
9157 const Value *OpSrcValue;
9158 int OpSrcValueOffset;
9159 unsigned OpSrcValueAlign;
9160 const MDNode *OpSrcTBAAInfo;
9161 bool IsOpLoad = FindAliasInfo(Chain.getNode(), OpPtr, OpSize,
9162 OpSrcValue, OpSrcValueOffset,
9166 // If chain is alias then stop here.
9167 if (!(IsLoad && IsOpLoad) &&
9168 isAlias(Ptr, Size, SrcValue, SrcValueOffset, SrcValueAlign,
9170 OpPtr, OpSize, OpSrcValue, OpSrcValueOffset,
9171 OpSrcValueAlign, OpSrcTBAAInfo)) {
9172 Aliases.push_back(Chain);
9174 // Look further up the chain.
9175 Chains.push_back(Chain.getOperand(0));
9181 case ISD::TokenFactor:
9182 // We have to check each of the operands of the token factor for "small"
9183 // token factors, so we queue them up. Adding the operands to the queue
9184 // (stack) in reverse order maintains the original order and increases the
9185 // likelihood that getNode will find a matching token factor (CSE.)
9186 if (Chain.getNumOperands() > 16) {
9187 Aliases.push_back(Chain);
9190 for (unsigned n = Chain.getNumOperands(); n;)
9191 Chains.push_back(Chain.getOperand(--n));
9196 // For all other instructions we will just have to take what we can get.
9197 Aliases.push_back(Chain);
9203 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes, looking
9204 /// for a better chain (aliasing node.)
9205 SDValue DAGCombiner::FindBetterChain(SDNode *N, SDValue OldChain) {
9206 SmallVector<SDValue, 8> Aliases; // Ops for replacing token factor.
9208 // Accumulate all the aliases to this node.
9209 GatherAllAliases(N, OldChain, Aliases);
9211 // If no operands then chain to entry token.
9212 if (Aliases.size() == 0)
9213 return DAG.getEntryNode();
9215 // If a single operand then chain to it. We don't need to revisit it.
9216 if (Aliases.size() == 1)
9219 // Construct a custom tailored token factor.
9220 return DAG.getNode(ISD::TokenFactor, N->getDebugLoc(), MVT::Other,
9221 &Aliases[0], Aliases.size());
9224 // SelectionDAG::Combine - This is the entry point for the file.
9226 void SelectionDAG::Combine(CombineLevel Level, AliasAnalysis &AA,
9227 CodeGenOpt::Level OptLevel) {
9228 /// run - This is the main entry point to this class.
9230 DAGCombiner(*this, AA, OptLevel).Run(Level);