1 //===-- DAGCombiner.cpp - Implement a DAG node combiner -------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Nate Begeman and is distributed under the
6 // University of Illinois Open Source 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 // FIXME: Missing folds
14 // sdiv, udiv, srem, urem (X, const) where X is an integer can be expanded into
15 // a sequence of multiplies, shifts, and adds. This should be controlled by
16 // some kind of hint from the target that int div is expensive.
17 // various folds of mulh[s,u] by constants such as -1, powers of 2, etc.
19 // FIXME: select C, pow2, pow2 -> something smart
20 // FIXME: trunc(select X, Y, Z) -> select X, trunc(Y), trunc(Z)
21 // FIXME: Dead stores -> nuke
22 // FIXME: shr X, (and Y,31) -> shr X, Y (TRICKY!)
23 // FIXME: mul (x, const) -> shifts + adds
24 // FIXME: undef values
25 // FIXME: divide by zero is currently left unfolded. do we want to turn this
27 // FIXME: select ne (select cc, 1, 0), 0, true, false -> select cc, true, false
29 //===----------------------------------------------------------------------===//
31 #define DEBUG_TYPE "dagcombine"
32 #include "llvm/CodeGen/SelectionDAG.h"
33 #include "llvm/Analysis/AliasAnalysis.h"
34 #include "llvm/Target/TargetData.h"
35 #include "llvm/Target/TargetLowering.h"
36 #include "llvm/Target/TargetMachine.h"
37 #include "llvm/Target/TargetOptions.h"
38 #include "llvm/ADT/SmallPtrSet.h"
39 #include "llvm/ADT/Statistic.h"
40 #include "llvm/Support/Alignment.h"
41 #include "llvm/Support/Compiler.h"
42 #include "llvm/Support/CommandLine.h"
43 #include "llvm/Support/Debug.h"
44 #include "llvm/Support/MathExtras.h"
48 STATISTIC(NodesCombined , "Number of dag nodes combined");
49 STATISTIC(PreIndexedNodes , "Number of pre-indexed nodes created");
50 STATISTIC(PostIndexedNodes, "Number of post-indexed nodes created");
55 ViewDAGCombine1("view-dag-combine1-dags", cl::Hidden,
56 cl::desc("Pop up a window to show dags before the first "
59 ViewDAGCombine2("view-dag-combine2-dags", cl::Hidden,
60 cl::desc("Pop up a window to show dags before the second "
63 static const bool ViewDAGCombine1 = false;
64 static const bool ViewDAGCombine2 = false;
68 CombinerAA("combiner-alias-analysis", cl::Hidden,
69 cl::desc("Turn on alias analysis during testing"));
72 CombinerGlobalAA("combiner-global-alias-analysis", cl::Hidden,
73 cl::desc("Include global information in alias analysis"));
75 //------------------------------ DAGCombiner ---------------------------------//
77 class VISIBILITY_HIDDEN DAGCombiner {
82 // Worklist of all of the nodes that need to be simplified.
83 std::vector<SDNode*> WorkList;
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 /// removeFromWorkList - remove all instances of N from the worklist.
100 void removeFromWorkList(SDNode *N) {
101 WorkList.erase(std::remove(WorkList.begin(), WorkList.end(), N),
105 /// visit - call the node-specific routine that knows how to fold each
106 /// particular type of node.
107 SDOperand visit(SDNode *N);
110 /// AddToWorkList - Add to the work list making sure it's instance is at the
111 /// the back (next to be processed.)
112 void AddToWorkList(SDNode *N) {
113 removeFromWorkList(N);
114 WorkList.push_back(N);
117 SDOperand CombineTo(SDNode *N, const SDOperand *To, unsigned NumTo,
119 assert(N->getNumValues() == NumTo && "Broken CombineTo call!");
121 DOUT << "\nReplacing.1 "; DEBUG(N->dump(&DAG));
122 DOUT << "\nWith: "; DEBUG(To[0].Val->dump(&DAG));
123 DOUT << " and " << NumTo-1 << " other values\n";
124 std::vector<SDNode*> NowDead;
125 DAG.ReplaceAllUsesWith(N, To, &NowDead);
128 // Push the new nodes and any users onto the worklist
129 for (unsigned i = 0, e = NumTo; i != e; ++i) {
130 AddToWorkList(To[i].Val);
131 AddUsersToWorkList(To[i].Val);
135 // Nodes can be reintroduced into the worklist. Make sure we do not
136 // process a node that has been replaced.
137 removeFromWorkList(N);
138 for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
139 removeFromWorkList(NowDead[i]);
141 // Finally, since the node is now dead, remove it from the graph.
143 return SDOperand(N, 0);
146 SDOperand CombineTo(SDNode *N, SDOperand Res, bool AddTo = true) {
147 return CombineTo(N, &Res, 1, AddTo);
150 SDOperand CombineTo(SDNode *N, SDOperand Res0, SDOperand Res1,
152 SDOperand To[] = { Res0, Res1 };
153 return CombineTo(N, To, 2, AddTo);
157 /// SimplifyDemandedBits - Check the specified integer node value to see if
158 /// it can be simplified or if things it uses can be simplified by bit
159 /// propagation. If so, return true.
160 bool SimplifyDemandedBits(SDOperand Op, uint64_t Demanded = ~0ULL) {
161 TargetLowering::TargetLoweringOpt TLO(DAG);
162 uint64_t KnownZero, KnownOne;
163 Demanded &= MVT::getIntVTBitMask(Op.getValueType());
164 if (!TLI.SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO))
168 AddToWorkList(Op.Val);
170 // Replace the old value with the new one.
172 DOUT << "\nReplacing.2 "; DEBUG(TLO.Old.Val->dump(&DAG));
173 DOUT << "\nWith: "; DEBUG(TLO.New.Val->dump(&DAG));
176 std::vector<SDNode*> NowDead;
177 DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New, &NowDead);
179 // Push the new node and any (possibly new) users onto the worklist.
180 AddToWorkList(TLO.New.Val);
181 AddUsersToWorkList(TLO.New.Val);
183 // Nodes can end up on the worklist more than once. Make sure we do
184 // not process a node that has been replaced.
185 for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
186 removeFromWorkList(NowDead[i]);
188 // Finally, if the node is now dead, remove it from the graph. The node
189 // may not be dead if the replacement process recursively simplified to
190 // something else needing this node.
191 if (TLO.Old.Val->use_empty()) {
192 removeFromWorkList(TLO.Old.Val);
194 // If the operands of this node are only used by the node, they will now
195 // be dead. Make sure to visit them first to delete dead nodes early.
196 for (unsigned i = 0, e = TLO.Old.Val->getNumOperands(); i != e; ++i)
197 if (TLO.Old.Val->getOperand(i).Val->hasOneUse())
198 AddToWorkList(TLO.Old.Val->getOperand(i).Val);
200 DAG.DeleteNode(TLO.Old.Val);
205 bool CombineToPreIndexedLoadStore(SDNode *N);
206 bool CombineToPostIndexedLoadStore(SDNode *N);
209 /// combine - call the node-specific routine that knows how to fold each
210 /// particular type of node. If that doesn't do anything, try the
211 /// target-specific DAG combines.
212 SDOperand combine(SDNode *N);
214 // Visitation implementation - Implement dag node combining for different
215 // node types. The semantics are as follows:
217 // SDOperand.Val == 0 - No change was made
218 // SDOperand.Val == N - N was replaced, is dead, and is already handled.
219 // otherwise - N should be replaced by the returned Operand.
221 SDOperand visitTokenFactor(SDNode *N);
222 SDOperand visitADD(SDNode *N);
223 SDOperand visitSUB(SDNode *N);
224 SDOperand visitADDC(SDNode *N);
225 SDOperand visitADDE(SDNode *N);
226 SDOperand visitMUL(SDNode *N);
227 SDOperand visitSDIV(SDNode *N);
228 SDOperand visitUDIV(SDNode *N);
229 SDOperand visitSREM(SDNode *N);
230 SDOperand visitUREM(SDNode *N);
231 SDOperand visitMULHU(SDNode *N);
232 SDOperand visitMULHS(SDNode *N);
233 SDOperand visitSMUL_LOHI(SDNode *N);
234 SDOperand visitUMUL_LOHI(SDNode *N);
235 SDOperand visitSDIVREM(SDNode *N);
236 SDOperand visitUDIVREM(SDNode *N);
237 SDOperand visitAND(SDNode *N);
238 SDOperand visitOR(SDNode *N);
239 SDOperand visitXOR(SDNode *N);
240 SDOperand SimplifyVBinOp(SDNode *N);
241 SDOperand visitSHL(SDNode *N);
242 SDOperand visitSRA(SDNode *N);
243 SDOperand visitSRL(SDNode *N);
244 SDOperand visitCTLZ(SDNode *N);
245 SDOperand visitCTTZ(SDNode *N);
246 SDOperand visitCTPOP(SDNode *N);
247 SDOperand visitSELECT(SDNode *N);
248 SDOperand visitSELECT_CC(SDNode *N);
249 SDOperand visitSETCC(SDNode *N);
250 SDOperand visitSIGN_EXTEND(SDNode *N);
251 SDOperand visitZERO_EXTEND(SDNode *N);
252 SDOperand visitANY_EXTEND(SDNode *N);
253 SDOperand visitSIGN_EXTEND_INREG(SDNode *N);
254 SDOperand visitTRUNCATE(SDNode *N);
255 SDOperand visitBIT_CONVERT(SDNode *N);
256 SDOperand visitFADD(SDNode *N);
257 SDOperand visitFSUB(SDNode *N);
258 SDOperand visitFMUL(SDNode *N);
259 SDOperand visitFDIV(SDNode *N);
260 SDOperand visitFREM(SDNode *N);
261 SDOperand visitFCOPYSIGN(SDNode *N);
262 SDOperand visitSINT_TO_FP(SDNode *N);
263 SDOperand visitUINT_TO_FP(SDNode *N);
264 SDOperand visitFP_TO_SINT(SDNode *N);
265 SDOperand visitFP_TO_UINT(SDNode *N);
266 SDOperand visitFP_ROUND(SDNode *N);
267 SDOperand visitFP_ROUND_INREG(SDNode *N);
268 SDOperand visitFP_EXTEND(SDNode *N);
269 SDOperand visitFNEG(SDNode *N);
270 SDOperand visitFABS(SDNode *N);
271 SDOperand visitBRCOND(SDNode *N);
272 SDOperand visitBR_CC(SDNode *N);
273 SDOperand visitLOAD(SDNode *N);
274 SDOperand visitSTORE(SDNode *N);
275 SDOperand visitINSERT_VECTOR_ELT(SDNode *N);
276 SDOperand visitEXTRACT_VECTOR_ELT(SDNode *N);
277 SDOperand visitBUILD_VECTOR(SDNode *N);
278 SDOperand visitCONCAT_VECTORS(SDNode *N);
279 SDOperand visitVECTOR_SHUFFLE(SDNode *N);
281 SDOperand XformToShuffleWithZero(SDNode *N);
282 SDOperand ReassociateOps(unsigned Opc, SDOperand LHS, SDOperand RHS);
284 bool SimplifySelectOps(SDNode *SELECT, SDOperand LHS, SDOperand RHS);
285 SDOperand SimplifyBinOpWithSameOpcodeHands(SDNode *N);
286 SDOperand SimplifySelect(SDOperand N0, SDOperand N1, SDOperand N2);
287 SDOperand SimplifySelectCC(SDOperand N0, SDOperand N1, SDOperand N2,
288 SDOperand N3, ISD::CondCode CC,
289 bool NotExtCompare = false);
290 SDOperand SimplifySetCC(MVT::ValueType VT, SDOperand N0, SDOperand N1,
291 ISD::CondCode Cond, bool foldBooleans = true);
292 bool SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp, unsigned HiOp);
293 SDOperand ConstantFoldBIT_CONVERTofBUILD_VECTOR(SDNode *, MVT::ValueType);
294 SDOperand BuildSDIV(SDNode *N);
295 SDOperand BuildUDIV(SDNode *N);
296 SDNode *MatchRotate(SDOperand LHS, SDOperand RHS);
297 SDOperand ReduceLoadWidth(SDNode *N);
299 SDOperand GetDemandedBits(SDOperand V, uint64_t Mask);
301 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
302 /// looking for aliasing nodes and adding them to the Aliases vector.
303 void GatherAllAliases(SDNode *N, SDOperand OriginalChain,
304 SmallVector<SDOperand, 8> &Aliases);
306 /// isAlias - Return true if there is any possibility that the two addresses
308 bool isAlias(SDOperand Ptr1, int64_t Size1,
309 const Value *SrcValue1, int SrcValueOffset1,
310 SDOperand Ptr2, int64_t Size2,
311 const Value *SrcValue2, int SrcValueOffset2);
313 /// FindAliasInfo - Extracts the relevant alias information from the memory
314 /// node. Returns true if the operand was a load.
315 bool FindAliasInfo(SDNode *N,
316 SDOperand &Ptr, int64_t &Size,
317 const Value *&SrcValue, int &SrcValueOffset);
319 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes,
320 /// looking for a better chain (aliasing node.)
321 SDOperand FindBetterChain(SDNode *N, SDOperand Chain);
324 DAGCombiner(SelectionDAG &D, AliasAnalysis &A)
326 TLI(D.getTargetLoweringInfo()),
327 AfterLegalize(false),
330 /// Run - runs the dag combiner on all nodes in the work list
331 void Run(bool RunningAfterLegalize);
335 //===----------------------------------------------------------------------===//
336 // TargetLowering::DAGCombinerInfo implementation
337 //===----------------------------------------------------------------------===//
339 void TargetLowering::DAGCombinerInfo::AddToWorklist(SDNode *N) {
340 ((DAGCombiner*)DC)->AddToWorkList(N);
343 SDOperand TargetLowering::DAGCombinerInfo::
344 CombineTo(SDNode *N, const std::vector<SDOperand> &To) {
345 return ((DAGCombiner*)DC)->CombineTo(N, &To[0], To.size());
348 SDOperand TargetLowering::DAGCombinerInfo::
349 CombineTo(SDNode *N, SDOperand Res) {
350 return ((DAGCombiner*)DC)->CombineTo(N, Res);
354 SDOperand TargetLowering::DAGCombinerInfo::
355 CombineTo(SDNode *N, SDOperand Res0, SDOperand Res1) {
356 return ((DAGCombiner*)DC)->CombineTo(N, Res0, Res1);
360 //===----------------------------------------------------------------------===//
362 //===----------------------------------------------------------------------===//
364 /// isNegatibleForFree - Return 1 if we can compute the negated form of the
365 /// specified expression for the same cost as the expression itself, or 2 if we
366 /// can compute the negated form more cheaply than the expression itself.
367 static char isNegatibleForFree(SDOperand Op, unsigned Depth = 0) {
368 // No compile time optimizations on this type.
369 if (Op.getValueType() == MVT::ppcf128)
372 // fneg is removable even if it has multiple uses.
373 if (Op.getOpcode() == ISD::FNEG) return 2;
375 // Don't allow anything with multiple uses.
376 if (!Op.hasOneUse()) return 0;
378 // Don't recurse exponentially.
379 if (Depth > 6) return 0;
381 switch (Op.getOpcode()) {
382 default: return false;
383 case ISD::ConstantFP:
386 // FIXME: determine better conditions for this xform.
387 if (!UnsafeFPMath) return 0;
390 if (char V = isNegatibleForFree(Op.getOperand(0), Depth+1))
393 return isNegatibleForFree(Op.getOperand(1), Depth+1);
395 // We can't turn -(A-B) into B-A when we honor signed zeros.
396 if (!UnsafeFPMath) return 0;
403 if (HonorSignDependentRoundingFPMath()) return 0;
405 // -(X*Y) -> (-X * Y) or (X*-Y)
406 if (char V = isNegatibleForFree(Op.getOperand(0), Depth+1))
409 return isNegatibleForFree(Op.getOperand(1), Depth+1);
414 return isNegatibleForFree(Op.getOperand(0), Depth+1);
418 /// GetNegatedExpression - If isNegatibleForFree returns true, this function
419 /// returns the newly negated expression.
420 static SDOperand GetNegatedExpression(SDOperand Op, SelectionDAG &DAG,
421 unsigned Depth = 0) {
422 // fneg is removable even if it has multiple uses.
423 if (Op.getOpcode() == ISD::FNEG) return Op.getOperand(0);
425 // Don't allow anything with multiple uses.
426 assert(Op.hasOneUse() && "Unknown reuse!");
428 assert(Depth <= 6 && "GetNegatedExpression doesn't match isNegatibleForFree");
429 switch (Op.getOpcode()) {
430 default: assert(0 && "Unknown code");
431 case ISD::ConstantFP: {
432 APFloat V = cast<ConstantFPSDNode>(Op)->getValueAPF();
434 return DAG.getConstantFP(V, Op.getValueType());
437 // FIXME: determine better conditions for this xform.
438 assert(UnsafeFPMath);
441 if (isNegatibleForFree(Op.getOperand(0), Depth+1))
442 return DAG.getNode(ISD::FSUB, Op.getValueType(),
443 GetNegatedExpression(Op.getOperand(0), DAG, Depth+1),
446 return DAG.getNode(ISD::FSUB, Op.getValueType(),
447 GetNegatedExpression(Op.getOperand(1), DAG, Depth+1),
450 // We can't turn -(A-B) into B-A when we honor signed zeros.
451 assert(UnsafeFPMath);
454 if (ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(Op.getOperand(0)))
455 if (N0CFP->getValueAPF().isZero())
456 return Op.getOperand(1);
459 return DAG.getNode(ISD::FSUB, Op.getValueType(), Op.getOperand(1),
464 assert(!HonorSignDependentRoundingFPMath());
467 if (isNegatibleForFree(Op.getOperand(0), Depth+1))
468 return DAG.getNode(Op.getOpcode(), Op.getValueType(),
469 GetNegatedExpression(Op.getOperand(0), DAG, Depth+1),
473 return DAG.getNode(Op.getOpcode(), Op.getValueType(),
475 GetNegatedExpression(Op.getOperand(1), DAG, Depth+1));
480 return DAG.getNode(Op.getOpcode(), Op.getValueType(),
481 GetNegatedExpression(Op.getOperand(0), DAG, Depth+1));
486 // isSetCCEquivalent - Return true if this node is a setcc, or is a select_cc
487 // that selects between the values 1 and 0, making it equivalent to a setcc.
488 // Also, set the incoming LHS, RHS, and CC references to the appropriate
489 // nodes based on the type of node we are checking. This simplifies life a
490 // bit for the callers.
491 static bool isSetCCEquivalent(SDOperand N, SDOperand &LHS, SDOperand &RHS,
493 if (N.getOpcode() == ISD::SETCC) {
494 LHS = N.getOperand(0);
495 RHS = N.getOperand(1);
496 CC = N.getOperand(2);
499 if (N.getOpcode() == ISD::SELECT_CC &&
500 N.getOperand(2).getOpcode() == ISD::Constant &&
501 N.getOperand(3).getOpcode() == ISD::Constant &&
502 cast<ConstantSDNode>(N.getOperand(2))->getValue() == 1 &&
503 cast<ConstantSDNode>(N.getOperand(3))->isNullValue()) {
504 LHS = N.getOperand(0);
505 RHS = N.getOperand(1);
506 CC = N.getOperand(4);
512 // isOneUseSetCC - Return true if this is a SetCC-equivalent operation with only
513 // one use. If this is true, it allows the users to invert the operation for
514 // free when it is profitable to do so.
515 static bool isOneUseSetCC(SDOperand N) {
516 SDOperand N0, N1, N2;
517 if (isSetCCEquivalent(N, N0, N1, N2) && N.Val->hasOneUse())
522 SDOperand DAGCombiner::ReassociateOps(unsigned Opc, SDOperand N0, SDOperand N1){
523 MVT::ValueType VT = N0.getValueType();
524 // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one use
525 // reassoc. (op (op x, c1), c2) -> (op x, (op c1, c2))
526 if (N0.getOpcode() == Opc && isa<ConstantSDNode>(N0.getOperand(1))) {
527 if (isa<ConstantSDNode>(N1)) {
528 SDOperand OpNode = DAG.getNode(Opc, VT, N0.getOperand(1), N1);
529 AddToWorkList(OpNode.Val);
530 return DAG.getNode(Opc, VT, OpNode, N0.getOperand(0));
531 } else if (N0.hasOneUse()) {
532 SDOperand OpNode = DAG.getNode(Opc, VT, N0.getOperand(0), N1);
533 AddToWorkList(OpNode.Val);
534 return DAG.getNode(Opc, VT, OpNode, N0.getOperand(1));
537 // reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) iff x+c1 has one use
538 // reassoc. (op c2, (op x, c1)) -> (op x, (op c1, c2))
539 if (N1.getOpcode() == Opc && isa<ConstantSDNode>(N1.getOperand(1))) {
540 if (isa<ConstantSDNode>(N0)) {
541 SDOperand OpNode = DAG.getNode(Opc, VT, N1.getOperand(1), N0);
542 AddToWorkList(OpNode.Val);
543 return DAG.getNode(Opc, VT, OpNode, N1.getOperand(0));
544 } else if (N1.hasOneUse()) {
545 SDOperand OpNode = DAG.getNode(Opc, VT, N1.getOperand(0), N0);
546 AddToWorkList(OpNode.Val);
547 return DAG.getNode(Opc, VT, OpNode, N1.getOperand(1));
553 //===----------------------------------------------------------------------===//
554 // Main DAG Combiner implementation
555 //===----------------------------------------------------------------------===//
557 void DAGCombiner::Run(bool RunningAfterLegalize) {
558 // set the instance variable, so that the various visit routines may use it.
559 AfterLegalize = RunningAfterLegalize;
561 // Add all the dag nodes to the worklist.
562 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
563 E = DAG.allnodes_end(); I != E; ++I)
564 WorkList.push_back(I);
566 // Create a dummy node (which is not added to allnodes), that adds a reference
567 // to the root node, preventing it from being deleted, and tracking any
568 // changes of the root.
569 HandleSDNode Dummy(DAG.getRoot());
571 // The root of the dag may dangle to deleted nodes until the dag combiner is
572 // done. Set it to null to avoid confusion.
573 DAG.setRoot(SDOperand());
575 // while the worklist isn't empty, inspect the node on the end of it and
576 // try and combine it.
577 while (!WorkList.empty()) {
578 SDNode *N = WorkList.back();
581 // If N has no uses, it is dead. Make sure to revisit all N's operands once
582 // N is deleted from the DAG, since they too may now be dead or may have a
583 // reduced number of uses, allowing other xforms.
584 if (N->use_empty() && N != &Dummy) {
585 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
586 AddToWorkList(N->getOperand(i).Val);
592 SDOperand RV = combine(N);
596 // If we get back the same node we passed in, rather than a new node or
597 // zero, we know that the node must have defined multiple values and
598 // CombineTo was used. Since CombineTo takes care of the worklist
599 // mechanics for us, we have no work to do in this case.
601 assert(N->getOpcode() != ISD::DELETED_NODE &&
602 RV.Val->getOpcode() != ISD::DELETED_NODE &&
603 "Node was deleted but visit returned new node!");
605 DOUT << "\nReplacing.3 "; DEBUG(N->dump(&DAG));
606 DOUT << "\nWith: "; DEBUG(RV.Val->dump(&DAG));
608 std::vector<SDNode*> NowDead;
609 if (N->getNumValues() == RV.Val->getNumValues())
610 DAG.ReplaceAllUsesWith(N, RV.Val, &NowDead);
612 assert(N->getValueType(0) == RV.getValueType() && "Type mismatch");
614 DAG.ReplaceAllUsesWith(N, &OpV, &NowDead);
617 // Push the new node and any users onto the worklist
618 AddToWorkList(RV.Val);
619 AddUsersToWorkList(RV.Val);
621 // Nodes can be reintroduced into the worklist. Make sure we do not
622 // process a node that has been replaced.
623 removeFromWorkList(N);
624 for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
625 removeFromWorkList(NowDead[i]);
627 // Finally, since the node is now dead, remove it from the graph.
633 // If the root changed (e.g. it was a dead load, update the root).
634 DAG.setRoot(Dummy.getValue());
637 SDOperand DAGCombiner::visit(SDNode *N) {
638 switch(N->getOpcode()) {
640 case ISD::TokenFactor: return visitTokenFactor(N);
641 case ISD::ADD: return visitADD(N);
642 case ISD::SUB: return visitSUB(N);
643 case ISD::ADDC: return visitADDC(N);
644 case ISD::ADDE: return visitADDE(N);
645 case ISD::MUL: return visitMUL(N);
646 case ISD::SDIV: return visitSDIV(N);
647 case ISD::UDIV: return visitUDIV(N);
648 case ISD::SREM: return visitSREM(N);
649 case ISD::UREM: return visitUREM(N);
650 case ISD::MULHU: return visitMULHU(N);
651 case ISD::MULHS: return visitMULHS(N);
652 case ISD::SMUL_LOHI: return visitSMUL_LOHI(N);
653 case ISD::UMUL_LOHI: return visitUMUL_LOHI(N);
654 case ISD::SDIVREM: return visitSDIVREM(N);
655 case ISD::UDIVREM: return visitUDIVREM(N);
656 case ISD::AND: return visitAND(N);
657 case ISD::OR: return visitOR(N);
658 case ISD::XOR: return visitXOR(N);
659 case ISD::SHL: return visitSHL(N);
660 case ISD::SRA: return visitSRA(N);
661 case ISD::SRL: return visitSRL(N);
662 case ISD::CTLZ: return visitCTLZ(N);
663 case ISD::CTTZ: return visitCTTZ(N);
664 case ISD::CTPOP: return visitCTPOP(N);
665 case ISD::SELECT: return visitSELECT(N);
666 case ISD::SELECT_CC: return visitSELECT_CC(N);
667 case ISD::SETCC: return visitSETCC(N);
668 case ISD::SIGN_EXTEND: return visitSIGN_EXTEND(N);
669 case ISD::ZERO_EXTEND: return visitZERO_EXTEND(N);
670 case ISD::ANY_EXTEND: return visitANY_EXTEND(N);
671 case ISD::SIGN_EXTEND_INREG: return visitSIGN_EXTEND_INREG(N);
672 case ISD::TRUNCATE: return visitTRUNCATE(N);
673 case ISD::BIT_CONVERT: return visitBIT_CONVERT(N);
674 case ISD::FADD: return visitFADD(N);
675 case ISD::FSUB: return visitFSUB(N);
676 case ISD::FMUL: return visitFMUL(N);
677 case ISD::FDIV: return visitFDIV(N);
678 case ISD::FREM: return visitFREM(N);
679 case ISD::FCOPYSIGN: return visitFCOPYSIGN(N);
680 case ISD::SINT_TO_FP: return visitSINT_TO_FP(N);
681 case ISD::UINT_TO_FP: return visitUINT_TO_FP(N);
682 case ISD::FP_TO_SINT: return visitFP_TO_SINT(N);
683 case ISD::FP_TO_UINT: return visitFP_TO_UINT(N);
684 case ISD::FP_ROUND: return visitFP_ROUND(N);
685 case ISD::FP_ROUND_INREG: return visitFP_ROUND_INREG(N);
686 case ISD::FP_EXTEND: return visitFP_EXTEND(N);
687 case ISD::FNEG: return visitFNEG(N);
688 case ISD::FABS: return visitFABS(N);
689 case ISD::BRCOND: return visitBRCOND(N);
690 case ISD::BR_CC: return visitBR_CC(N);
691 case ISD::LOAD: return visitLOAD(N);
692 case ISD::STORE: return visitSTORE(N);
693 case ISD::INSERT_VECTOR_ELT: return visitINSERT_VECTOR_ELT(N);
694 case ISD::EXTRACT_VECTOR_ELT: return visitEXTRACT_VECTOR_ELT(N);
695 case ISD::BUILD_VECTOR: return visitBUILD_VECTOR(N);
696 case ISD::CONCAT_VECTORS: return visitCONCAT_VECTORS(N);
697 case ISD::VECTOR_SHUFFLE: return visitVECTOR_SHUFFLE(N);
702 SDOperand DAGCombiner::combine(SDNode *N) {
704 SDOperand RV = visit(N);
706 // If nothing happened, try a target-specific DAG combine.
708 assert(N->getOpcode() != ISD::DELETED_NODE &&
709 "Node was deleted but visit returned NULL!");
711 if (N->getOpcode() >= ISD::BUILTIN_OP_END ||
712 TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode())) {
714 // Expose the DAG combiner to the target combiner impls.
715 TargetLowering::DAGCombinerInfo
716 DagCombineInfo(DAG, !AfterLegalize, false, this);
718 RV = TLI.PerformDAGCombine(N, DagCombineInfo);
725 /// getInputChainForNode - Given a node, return its input chain if it has one,
726 /// otherwise return a null sd operand.
727 static SDOperand getInputChainForNode(SDNode *N) {
728 if (unsigned NumOps = N->getNumOperands()) {
729 if (N->getOperand(0).getValueType() == MVT::Other)
730 return N->getOperand(0);
731 else if (N->getOperand(NumOps-1).getValueType() == MVT::Other)
732 return N->getOperand(NumOps-1);
733 for (unsigned i = 1; i < NumOps-1; ++i)
734 if (N->getOperand(i).getValueType() == MVT::Other)
735 return N->getOperand(i);
737 return SDOperand(0, 0);
740 SDOperand DAGCombiner::visitTokenFactor(SDNode *N) {
741 // If N has two operands, where one has an input chain equal to the other,
742 // the 'other' chain is redundant.
743 if (N->getNumOperands() == 2) {
744 if (getInputChainForNode(N->getOperand(0).Val) == N->getOperand(1))
745 return N->getOperand(0);
746 if (getInputChainForNode(N->getOperand(1).Val) == N->getOperand(0))
747 return N->getOperand(1);
750 SmallVector<SDNode *, 8> TFs; // List of token factors to visit.
751 SmallVector<SDOperand, 8> Ops; // Ops for replacing token factor.
752 SmallPtrSet<SDNode*, 16> SeenOps;
753 bool Changed = false; // If we should replace this token factor.
755 // Start out with this token factor.
758 // Iterate through token factors. The TFs grows when new token factors are
760 for (unsigned i = 0; i < TFs.size(); ++i) {
763 // Check each of the operands.
764 for (unsigned i = 0, ie = TF->getNumOperands(); i != ie; ++i) {
765 SDOperand Op = TF->getOperand(i);
767 switch (Op.getOpcode()) {
768 case ISD::EntryToken:
769 // Entry tokens don't need to be added to the list. They are
774 case ISD::TokenFactor:
775 if ((CombinerAA || Op.hasOneUse()) &&
776 std::find(TFs.begin(), TFs.end(), Op.Val) == TFs.end()) {
777 // Queue up for processing.
778 TFs.push_back(Op.Val);
779 // Clean up in case the token factor is removed.
780 AddToWorkList(Op.Val);
787 // Only add if it isn't already in the list.
788 if (SeenOps.insert(Op.Val))
799 // If we've change things around then replace token factor.
801 if (Ops.size() == 0) {
802 // The entry token is the only possible outcome.
803 Result = DAG.getEntryNode();
805 // New and improved token factor.
806 Result = DAG.getNode(ISD::TokenFactor, MVT::Other, &Ops[0], Ops.size());
809 // Don't add users to work list.
810 return CombineTo(N, Result, false);
817 SDOperand combineShlAddConstant(SDOperand N0, SDOperand N1, SelectionDAG &DAG) {
818 MVT::ValueType VT = N0.getValueType();
819 SDOperand N00 = N0.getOperand(0);
820 SDOperand N01 = N0.getOperand(1);
821 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N01);
822 if (N01C && N00.getOpcode() == ISD::ADD && N00.Val->hasOneUse() &&
823 isa<ConstantSDNode>(N00.getOperand(1))) {
824 N0 = DAG.getNode(ISD::ADD, VT,
825 DAG.getNode(ISD::SHL, VT, N00.getOperand(0), N01),
826 DAG.getNode(ISD::SHL, VT, N00.getOperand(1), N01));
827 return DAG.getNode(ISD::ADD, VT, N0, N1);
833 SDOperand combineSelectAndUse(SDNode *N, SDOperand Slct, SDOperand OtherOp,
835 MVT::ValueType VT = N->getValueType(0);
836 unsigned Opc = N->getOpcode();
837 bool isSlctCC = Slct.getOpcode() == ISD::SELECT_CC;
838 SDOperand LHS = isSlctCC ? Slct.getOperand(2) : Slct.getOperand(1);
839 SDOperand RHS = isSlctCC ? Slct.getOperand(3) : Slct.getOperand(2);
840 ISD::CondCode CC = ISD::SETCC_INVALID;
842 CC = cast<CondCodeSDNode>(Slct.getOperand(4))->get();
844 SDOperand CCOp = Slct.getOperand(0);
845 if (CCOp.getOpcode() == ISD::SETCC)
846 CC = cast<CondCodeSDNode>(CCOp.getOperand(2))->get();
849 bool DoXform = false;
851 assert ((Opc == ISD::ADD || (Opc == ISD::SUB && Slct == N->getOperand(1))) &&
853 if (LHS.getOpcode() == ISD::Constant &&
854 cast<ConstantSDNode>(LHS)->isNullValue())
856 else if (CC != ISD::SETCC_INVALID &&
857 RHS.getOpcode() == ISD::Constant &&
858 cast<ConstantSDNode>(RHS)->isNullValue()) {
860 bool isInt = MVT::isInteger(isSlctCC ? Slct.getOperand(0).getValueType()
861 : Slct.getOperand(0).getOperand(0).getValueType());
862 CC = ISD::getSetCCInverse(CC, isInt);
868 SDOperand Result = DAG.getNode(Opc, VT, OtherOp, RHS);
870 return DAG.getSelectCC(OtherOp, Result,
871 Slct.getOperand(0), Slct.getOperand(1), CC);
872 SDOperand CCOp = Slct.getOperand(0);
874 CCOp = DAG.getSetCC(CCOp.getValueType(), CCOp.getOperand(0),
875 CCOp.getOperand(1), CC);
876 return DAG.getNode(ISD::SELECT, VT, CCOp, OtherOp, Result);
881 SDOperand DAGCombiner::visitADD(SDNode *N) {
882 SDOperand N0 = N->getOperand(0);
883 SDOperand N1 = N->getOperand(1);
884 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
885 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
886 MVT::ValueType VT = N0.getValueType();
889 if (MVT::isVector(VT)) {
890 SDOperand FoldedVOp = SimplifyVBinOp(N);
891 if (FoldedVOp.Val) return FoldedVOp;
894 // fold (add x, undef) -> undef
895 if (N0.getOpcode() == ISD::UNDEF)
897 if (N1.getOpcode() == ISD::UNDEF)
899 // fold (add c1, c2) -> c1+c2
901 return DAG.getNode(ISD::ADD, VT, N0, N1);
902 // canonicalize constant to RHS
904 return DAG.getNode(ISD::ADD, VT, N1, N0);
905 // fold (add x, 0) -> x
906 if (N1C && N1C->isNullValue())
908 // fold ((c1-A)+c2) -> (c1+c2)-A
909 if (N1C && N0.getOpcode() == ISD::SUB)
910 if (ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getOperand(0)))
911 return DAG.getNode(ISD::SUB, VT,
912 DAG.getConstant(N1C->getValue()+N0C->getValue(), VT),
915 SDOperand RADD = ReassociateOps(ISD::ADD, N0, N1);
918 // fold ((0-A) + B) -> B-A
919 if (N0.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N0.getOperand(0)) &&
920 cast<ConstantSDNode>(N0.getOperand(0))->isNullValue())
921 return DAG.getNode(ISD::SUB, VT, N1, N0.getOperand(1));
922 // fold (A + (0-B)) -> A-B
923 if (N1.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N1.getOperand(0)) &&
924 cast<ConstantSDNode>(N1.getOperand(0))->isNullValue())
925 return DAG.getNode(ISD::SUB, VT, N0, N1.getOperand(1));
926 // fold (A+(B-A)) -> B
927 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(1))
928 return N1.getOperand(0);
930 if (!MVT::isVector(VT) && SimplifyDemandedBits(SDOperand(N, 0)))
931 return SDOperand(N, 0);
933 // fold (a+b) -> (a|b) iff a and b share no bits.
934 if (MVT::isInteger(VT) && !MVT::isVector(VT)) {
935 uint64_t LHSZero, LHSOne;
936 uint64_t RHSZero, RHSOne;
937 uint64_t Mask = MVT::getIntVTBitMask(VT);
938 DAG.ComputeMaskedBits(N0, Mask, LHSZero, LHSOne);
940 DAG.ComputeMaskedBits(N1, Mask, RHSZero, RHSOne);
942 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
943 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
944 if ((RHSZero & (~LHSZero & Mask)) == (~LHSZero & Mask) ||
945 (LHSZero & (~RHSZero & Mask)) == (~RHSZero & Mask))
946 return DAG.getNode(ISD::OR, VT, N0, N1);
950 // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
951 if (N0.getOpcode() == ISD::SHL && N0.Val->hasOneUse()) {
952 SDOperand Result = combineShlAddConstant(N0, N1, DAG);
953 if (Result.Val) return Result;
955 if (N1.getOpcode() == ISD::SHL && N1.Val->hasOneUse()) {
956 SDOperand Result = combineShlAddConstant(N1, N0, DAG);
957 if (Result.Val) return Result;
960 // fold (add (select cc, 0, c), x) -> (select cc, x, (add, x, c))
961 if (N0.getOpcode() == ISD::SELECT && N0.Val->hasOneUse()) {
962 SDOperand Result = combineSelectAndUse(N, N0, N1, DAG);
963 if (Result.Val) return Result;
965 if (N1.getOpcode() == ISD::SELECT && N1.Val->hasOneUse()) {
966 SDOperand Result = combineSelectAndUse(N, N1, N0, DAG);
967 if (Result.Val) return Result;
973 SDOperand DAGCombiner::visitADDC(SDNode *N) {
974 SDOperand N0 = N->getOperand(0);
975 SDOperand N1 = N->getOperand(1);
976 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
977 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
978 MVT::ValueType VT = N0.getValueType();
980 // If the flag result is dead, turn this into an ADD.
981 if (N->hasNUsesOfValue(0, 1))
982 return CombineTo(N, DAG.getNode(ISD::ADD, VT, N1, N0),
983 DAG.getNode(ISD::CARRY_FALSE, MVT::Flag));
985 // canonicalize constant to RHS.
987 SDOperand Ops[] = { N1, N0 };
988 return DAG.getNode(ISD::ADDC, N->getVTList(), Ops, 2);
991 // fold (addc x, 0) -> x + no carry out
992 if (N1C && N1C->isNullValue())
993 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE, MVT::Flag));
995 // fold (addc a, b) -> (or a, b), CARRY_FALSE iff a and b share no bits.
996 uint64_t LHSZero, LHSOne;
997 uint64_t RHSZero, RHSOne;
998 uint64_t Mask = MVT::getIntVTBitMask(VT);
999 DAG.ComputeMaskedBits(N0, Mask, LHSZero, LHSOne);
1001 DAG.ComputeMaskedBits(N1, Mask, RHSZero, RHSOne);
1003 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1004 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1005 if ((RHSZero & (~LHSZero & Mask)) == (~LHSZero & Mask) ||
1006 (LHSZero & (~RHSZero & Mask)) == (~RHSZero & Mask))
1007 return CombineTo(N, DAG.getNode(ISD::OR, VT, N0, N1),
1008 DAG.getNode(ISD::CARRY_FALSE, MVT::Flag));
1014 SDOperand DAGCombiner::visitADDE(SDNode *N) {
1015 SDOperand N0 = N->getOperand(0);
1016 SDOperand N1 = N->getOperand(1);
1017 SDOperand CarryIn = N->getOperand(2);
1018 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1019 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1020 //MVT::ValueType VT = N0.getValueType();
1022 // canonicalize constant to RHS
1024 SDOperand Ops[] = { N1, N0, CarryIn };
1025 return DAG.getNode(ISD::ADDE, N->getVTList(), Ops, 3);
1028 // fold (adde x, y, false) -> (addc x, y)
1029 if (CarryIn.getOpcode() == ISD::CARRY_FALSE) {
1030 SDOperand Ops[] = { N1, N0 };
1031 return DAG.getNode(ISD::ADDC, N->getVTList(), Ops, 2);
1039 SDOperand DAGCombiner::visitSUB(SDNode *N) {
1040 SDOperand N0 = N->getOperand(0);
1041 SDOperand N1 = N->getOperand(1);
1042 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.Val);
1043 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
1044 MVT::ValueType VT = N0.getValueType();
1047 if (MVT::isVector(VT)) {
1048 SDOperand FoldedVOp = SimplifyVBinOp(N);
1049 if (FoldedVOp.Val) return FoldedVOp;
1052 // fold (sub x, x) -> 0
1054 return DAG.getConstant(0, N->getValueType(0));
1055 // fold (sub c1, c2) -> c1-c2
1057 return DAG.getNode(ISD::SUB, VT, N0, N1);
1058 // fold (sub x, c) -> (add x, -c)
1060 return DAG.getNode(ISD::ADD, VT, N0, DAG.getConstant(-N1C->getValue(), VT));
1061 // fold (A+B)-A -> B
1062 if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1)
1063 return N0.getOperand(1);
1064 // fold (A+B)-B -> A
1065 if (N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1)
1066 return N0.getOperand(0);
1067 // fold (sub x, (select cc, 0, c)) -> (select cc, x, (sub, x, c))
1068 if (N1.getOpcode() == ISD::SELECT && N1.Val->hasOneUse()) {
1069 SDOperand Result = combineSelectAndUse(N, N1, N0, DAG);
1070 if (Result.Val) return Result;
1072 // If either operand of a sub is undef, the result is undef
1073 if (N0.getOpcode() == ISD::UNDEF)
1075 if (N1.getOpcode() == ISD::UNDEF)
1081 SDOperand DAGCombiner::visitMUL(SDNode *N) {
1082 SDOperand N0 = N->getOperand(0);
1083 SDOperand N1 = N->getOperand(1);
1084 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1085 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1086 MVT::ValueType VT = N0.getValueType();
1089 if (MVT::isVector(VT)) {
1090 SDOperand FoldedVOp = SimplifyVBinOp(N);
1091 if (FoldedVOp.Val) return FoldedVOp;
1094 // fold (mul x, undef) -> 0
1095 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
1096 return DAG.getConstant(0, VT);
1097 // fold (mul c1, c2) -> c1*c2
1099 return DAG.getNode(ISD::MUL, VT, N0, N1);
1100 // canonicalize constant to RHS
1102 return DAG.getNode(ISD::MUL, VT, N1, N0);
1103 // fold (mul x, 0) -> 0
1104 if (N1C && N1C->isNullValue())
1106 // fold (mul x, -1) -> 0-x
1107 if (N1C && N1C->isAllOnesValue())
1108 return DAG.getNode(ISD::SUB, VT, DAG.getConstant(0, VT), N0);
1109 // fold (mul x, (1 << c)) -> x << c
1110 if (N1C && isPowerOf2_64(N1C->getValue()))
1111 return DAG.getNode(ISD::SHL, VT, N0,
1112 DAG.getConstant(Log2_64(N1C->getValue()),
1113 TLI.getShiftAmountTy()));
1114 // fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c
1115 if (N1C && isPowerOf2_64(-N1C->getSignExtended())) {
1116 // FIXME: If the input is something that is easily negated (e.g. a
1117 // single-use add), we should put the negate there.
1118 return DAG.getNode(ISD::SUB, VT, DAG.getConstant(0, VT),
1119 DAG.getNode(ISD::SHL, VT, N0,
1120 DAG.getConstant(Log2_64(-N1C->getSignExtended()),
1121 TLI.getShiftAmountTy())));
1124 // (mul (shl X, c1), c2) -> (mul X, c2 << c1)
1125 if (N1C && N0.getOpcode() == ISD::SHL &&
1126 isa<ConstantSDNode>(N0.getOperand(1))) {
1127 SDOperand C3 = DAG.getNode(ISD::SHL, VT, N1, N0.getOperand(1));
1128 AddToWorkList(C3.Val);
1129 return DAG.getNode(ISD::MUL, VT, N0.getOperand(0), C3);
1132 // Change (mul (shl X, C), Y) -> (shl (mul X, Y), C) when the shift has one
1135 SDOperand Sh(0,0), Y(0,0);
1136 // Check for both (mul (shl X, C), Y) and (mul Y, (shl X, C)).
1137 if (N0.getOpcode() == ISD::SHL && isa<ConstantSDNode>(N0.getOperand(1)) &&
1138 N0.Val->hasOneUse()) {
1140 } else if (N1.getOpcode() == ISD::SHL &&
1141 isa<ConstantSDNode>(N1.getOperand(1)) && N1.Val->hasOneUse()) {
1145 SDOperand Mul = DAG.getNode(ISD::MUL, VT, Sh.getOperand(0), Y);
1146 return DAG.getNode(ISD::SHL, VT, Mul, Sh.getOperand(1));
1149 // fold (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2)
1150 if (N1C && N0.getOpcode() == ISD::ADD && N0.Val->hasOneUse() &&
1151 isa<ConstantSDNode>(N0.getOperand(1))) {
1152 return DAG.getNode(ISD::ADD, VT,
1153 DAG.getNode(ISD::MUL, VT, N0.getOperand(0), N1),
1154 DAG.getNode(ISD::MUL, VT, N0.getOperand(1), N1));
1158 SDOperand RMUL = ReassociateOps(ISD::MUL, N0, N1);
1165 SDOperand DAGCombiner::visitSDIV(SDNode *N) {
1166 SDOperand N0 = N->getOperand(0);
1167 SDOperand N1 = N->getOperand(1);
1168 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.Val);
1169 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
1170 MVT::ValueType VT = N->getValueType(0);
1173 if (MVT::isVector(VT)) {
1174 SDOperand FoldedVOp = SimplifyVBinOp(N);
1175 if (FoldedVOp.Val) return FoldedVOp;
1178 // fold (sdiv c1, c2) -> c1/c2
1179 if (N0C && N1C && !N1C->isNullValue())
1180 return DAG.getNode(ISD::SDIV, VT, N0, N1);
1181 // fold (sdiv X, 1) -> X
1182 if (N1C && N1C->getSignExtended() == 1LL)
1184 // fold (sdiv X, -1) -> 0-X
1185 if (N1C && N1C->isAllOnesValue())
1186 return DAG.getNode(ISD::SUB, VT, DAG.getConstant(0, VT), N0);
1187 // If we know the sign bits of both operands are zero, strength reduce to a
1188 // udiv instead. Handles (X&15) /s 4 -> X&15 >> 2
1189 uint64_t SignBit = 1ULL << (MVT::getSizeInBits(VT)-1);
1190 if (DAG.MaskedValueIsZero(N1, SignBit) &&
1191 DAG.MaskedValueIsZero(N0, SignBit))
1192 return DAG.getNode(ISD::UDIV, N1.getValueType(), N0, N1);
1193 // fold (sdiv X, pow2) -> simple ops after legalize
1194 if (N1C && N1C->getValue() && !TLI.isIntDivCheap() &&
1195 (isPowerOf2_64(N1C->getSignExtended()) ||
1196 isPowerOf2_64(-N1C->getSignExtended()))) {
1197 // If dividing by powers of two is cheap, then don't perform the following
1199 if (TLI.isPow2DivCheap())
1201 int64_t pow2 = N1C->getSignExtended();
1202 int64_t abs2 = pow2 > 0 ? pow2 : -pow2;
1203 unsigned lg2 = Log2_64(abs2);
1204 // Splat the sign bit into the register
1205 SDOperand SGN = DAG.getNode(ISD::SRA, VT, N0,
1206 DAG.getConstant(MVT::getSizeInBits(VT)-1,
1207 TLI.getShiftAmountTy()));
1208 AddToWorkList(SGN.Val);
1209 // Add (N0 < 0) ? abs2 - 1 : 0;
1210 SDOperand SRL = DAG.getNode(ISD::SRL, VT, SGN,
1211 DAG.getConstant(MVT::getSizeInBits(VT)-lg2,
1212 TLI.getShiftAmountTy()));
1213 SDOperand ADD = DAG.getNode(ISD::ADD, VT, N0, SRL);
1214 AddToWorkList(SRL.Val);
1215 AddToWorkList(ADD.Val); // Divide by pow2
1216 SDOperand SRA = DAG.getNode(ISD::SRA, VT, ADD,
1217 DAG.getConstant(lg2, TLI.getShiftAmountTy()));
1218 // If we're dividing by a positive value, we're done. Otherwise, we must
1219 // negate the result.
1222 AddToWorkList(SRA.Val);
1223 return DAG.getNode(ISD::SUB, VT, DAG.getConstant(0, VT), SRA);
1225 // if integer divide is expensive and we satisfy the requirements, emit an
1226 // alternate sequence.
1227 if (N1C && (N1C->getSignExtended() < -1 || N1C->getSignExtended() > 1) &&
1228 !TLI.isIntDivCheap()) {
1229 SDOperand Op = BuildSDIV(N);
1230 if (Op.Val) return Op;
1234 if (N0.getOpcode() == ISD::UNDEF)
1235 return DAG.getConstant(0, VT);
1236 // X / undef -> undef
1237 if (N1.getOpcode() == ISD::UNDEF)
1243 SDOperand DAGCombiner::visitUDIV(SDNode *N) {
1244 SDOperand N0 = N->getOperand(0);
1245 SDOperand N1 = N->getOperand(1);
1246 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.Val);
1247 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
1248 MVT::ValueType VT = N->getValueType(0);
1251 if (MVT::isVector(VT)) {
1252 SDOperand FoldedVOp = SimplifyVBinOp(N);
1253 if (FoldedVOp.Val) return FoldedVOp;
1256 // fold (udiv c1, c2) -> c1/c2
1257 if (N0C && N1C && !N1C->isNullValue())
1258 return DAG.getNode(ISD::UDIV, VT, N0, N1);
1259 // fold (udiv x, (1 << c)) -> x >>u c
1260 if (N1C && isPowerOf2_64(N1C->getValue()))
1261 return DAG.getNode(ISD::SRL, VT, N0,
1262 DAG.getConstant(Log2_64(N1C->getValue()),
1263 TLI.getShiftAmountTy()));
1264 // fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) iff c is power of 2
1265 if (N1.getOpcode() == ISD::SHL) {
1266 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
1267 if (isPowerOf2_64(SHC->getValue())) {
1268 MVT::ValueType ADDVT = N1.getOperand(1).getValueType();
1269 SDOperand Add = DAG.getNode(ISD::ADD, ADDVT, N1.getOperand(1),
1270 DAG.getConstant(Log2_64(SHC->getValue()),
1272 AddToWorkList(Add.Val);
1273 return DAG.getNode(ISD::SRL, VT, N0, Add);
1277 // fold (udiv x, c) -> alternate
1278 if (N1C && N1C->getValue() && !TLI.isIntDivCheap()) {
1279 SDOperand Op = BuildUDIV(N);
1280 if (Op.Val) return Op;
1284 if (N0.getOpcode() == ISD::UNDEF)
1285 return DAG.getConstant(0, VT);
1286 // X / undef -> undef
1287 if (N1.getOpcode() == ISD::UNDEF)
1293 SDOperand DAGCombiner::visitSREM(SDNode *N) {
1294 SDOperand N0 = N->getOperand(0);
1295 SDOperand N1 = N->getOperand(1);
1296 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1297 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1298 MVT::ValueType VT = N->getValueType(0);
1300 // fold (srem c1, c2) -> c1%c2
1301 if (N0C && N1C && !N1C->isNullValue())
1302 return DAG.getNode(ISD::SREM, VT, N0, N1);
1303 // If we know the sign bits of both operands are zero, strength reduce to a
1304 // urem instead. Handles (X & 0x0FFFFFFF) %s 16 -> X&15
1305 uint64_t SignBit = 1ULL << (MVT::getSizeInBits(VT)-1);
1306 if (DAG.MaskedValueIsZero(N1, SignBit) &&
1307 DAG.MaskedValueIsZero(N0, SignBit))
1308 return DAG.getNode(ISD::UREM, VT, N0, N1);
1310 // Unconditionally lower X%C -> X-X/C*C. This allows the X/C logic to hack on
1311 // the remainder operation.
1312 if (N1C && !N1C->isNullValue()) {
1313 SDOperand Div = DAG.getNode(ISD::SDIV, VT, N0, N1);
1314 SDOperand Mul = DAG.getNode(ISD::MUL, VT, Div, N1);
1315 SDOperand Sub = DAG.getNode(ISD::SUB, VT, N0, Mul);
1316 AddToWorkList(Div.Val);
1317 AddToWorkList(Mul.Val);
1322 if (N0.getOpcode() == ISD::UNDEF)
1323 return DAG.getConstant(0, VT);
1324 // X % undef -> undef
1325 if (N1.getOpcode() == ISD::UNDEF)
1331 SDOperand DAGCombiner::visitUREM(SDNode *N) {
1332 SDOperand N0 = N->getOperand(0);
1333 SDOperand N1 = N->getOperand(1);
1334 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1335 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1336 MVT::ValueType VT = N->getValueType(0);
1338 // fold (urem c1, c2) -> c1%c2
1339 if (N0C && N1C && !N1C->isNullValue())
1340 return DAG.getNode(ISD::UREM, VT, N0, N1);
1341 // fold (urem x, pow2) -> (and x, pow2-1)
1342 if (N1C && !N1C->isNullValue() && isPowerOf2_64(N1C->getValue()))
1343 return DAG.getNode(ISD::AND, VT, N0, DAG.getConstant(N1C->getValue()-1,VT));
1344 // fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1))
1345 if (N1.getOpcode() == ISD::SHL) {
1346 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
1347 if (isPowerOf2_64(SHC->getValue())) {
1348 SDOperand Add = DAG.getNode(ISD::ADD, VT, N1,DAG.getConstant(~0ULL,VT));
1349 AddToWorkList(Add.Val);
1350 return DAG.getNode(ISD::AND, VT, N0, Add);
1355 // Unconditionally lower X%C -> X-X/C*C. This allows the X/C logic to hack on
1356 // the remainder operation.
1357 if (N1C && !N1C->isNullValue()) {
1358 SDOperand Div = DAG.getNode(ISD::UDIV, VT, N0, N1);
1359 SDOperand Mul = DAG.getNode(ISD::MUL, VT, Div, N1);
1360 SDOperand Sub = DAG.getNode(ISD::SUB, VT, N0, Mul);
1361 AddToWorkList(Div.Val);
1362 AddToWorkList(Mul.Val);
1367 if (N0.getOpcode() == ISD::UNDEF)
1368 return DAG.getConstant(0, VT);
1369 // X % undef -> undef
1370 if (N1.getOpcode() == ISD::UNDEF)
1376 SDOperand DAGCombiner::visitMULHS(SDNode *N) {
1377 SDOperand N0 = N->getOperand(0);
1378 SDOperand N1 = N->getOperand(1);
1379 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1380 MVT::ValueType VT = N->getValueType(0);
1382 // fold (mulhs x, 0) -> 0
1383 if (N1C && N1C->isNullValue())
1385 // fold (mulhs x, 1) -> (sra x, size(x)-1)
1386 if (N1C && N1C->getValue() == 1)
1387 return DAG.getNode(ISD::SRA, N0.getValueType(), N0,
1388 DAG.getConstant(MVT::getSizeInBits(N0.getValueType())-1,
1389 TLI.getShiftAmountTy()));
1390 // fold (mulhs x, undef) -> 0
1391 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
1392 return DAG.getConstant(0, VT);
1397 SDOperand DAGCombiner::visitMULHU(SDNode *N) {
1398 SDOperand N0 = N->getOperand(0);
1399 SDOperand N1 = N->getOperand(1);
1400 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1401 MVT::ValueType VT = N->getValueType(0);
1403 // fold (mulhu x, 0) -> 0
1404 if (N1C && N1C->isNullValue())
1406 // fold (mulhu x, 1) -> 0
1407 if (N1C && N1C->getValue() == 1)
1408 return DAG.getConstant(0, N0.getValueType());
1409 // fold (mulhu x, undef) -> 0
1410 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
1411 return DAG.getConstant(0, VT);
1416 /// SimplifyNodeWithTwoResults - Perform optimizations common to nodes that
1417 /// compute two values. LoOp and HiOp give the opcodes for the two computations
1418 /// that are being performed. Return true if a simplification was made.
1420 bool DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N,
1421 unsigned LoOp, unsigned HiOp) {
1422 // If the high half is not needed, just compute the low half.
1423 if (!N->hasAnyUseOfValue(1) &&
1425 TLI.isOperationLegal(LoOp, N->getValueType(0)))) {
1426 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0),
1427 DAG.getNode(LoOp, N->getValueType(0),
1429 N->getNumOperands()));
1433 // If the low half is not needed, just compute the high half.
1434 if (!N->hasAnyUseOfValue(0) &&
1436 TLI.isOperationLegal(HiOp, N->getValueType(1)))) {
1437 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1),
1438 DAG.getNode(HiOp, N->getValueType(1),
1440 N->getNumOperands()));
1444 // If the two computed results can be siplified separately, separate them.
1445 SDOperand Lo = DAG.getNode(LoOp, N->getValueType(0),
1446 N->op_begin(), N->getNumOperands());
1447 SDOperand Hi = DAG.getNode(HiOp, N->getValueType(1),
1448 N->op_begin(), N->getNumOperands());
1449 unsigned LoExists = !Lo.use_empty();
1450 unsigned HiExists = !Hi.use_empty();
1451 SDOperand LoOpt = Lo;
1452 SDOperand HiOpt = Hi;
1453 if (!LoExists || !HiExists) {
1454 SDOperand Pair = DAG.getNode(ISD::BUILD_PAIR, MVT::Other, Lo, Hi);
1455 assert(Pair.use_empty() && "Pair with type MVT::Other already exists!");
1456 LoOpt = combine(Lo.Val);
1457 HiOpt = combine(Hi.Val);
1459 LoOpt = Pair.getOperand(0);
1461 HiOpt = Pair.getOperand(1);
1462 DAG.DeleteNode(Pair.Val);
1464 if ((LoExists || LoOpt != Lo) &&
1465 (HiExists || HiOpt != Hi) &&
1466 TLI.isOperationLegal(LoOpt.getOpcode(), LoOpt.getValueType()) &&
1467 TLI.isOperationLegal(HiOpt.getOpcode(), HiOpt.getValueType())) {
1468 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), LoOpt);
1469 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1), HiOpt);
1476 SDOperand DAGCombiner::visitSMUL_LOHI(SDNode *N) {
1478 if (SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHS))
1484 SDOperand DAGCombiner::visitUMUL_LOHI(SDNode *N) {
1486 if (SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHU))
1492 SDOperand DAGCombiner::visitSDIVREM(SDNode *N) {
1494 if (SimplifyNodeWithTwoResults(N, ISD::SDIV, ISD::SREM))
1500 SDOperand DAGCombiner::visitUDIVREM(SDNode *N) {
1502 if (SimplifyNodeWithTwoResults(N, ISD::UDIV, ISD::UREM))
1508 /// SimplifyBinOpWithSameOpcodeHands - If this is a binary operator with
1509 /// two operands of the same opcode, try to simplify it.
1510 SDOperand DAGCombiner::SimplifyBinOpWithSameOpcodeHands(SDNode *N) {
1511 SDOperand N0 = N->getOperand(0), N1 = N->getOperand(1);
1512 MVT::ValueType VT = N0.getValueType();
1513 assert(N0.getOpcode() == N1.getOpcode() && "Bad input!");
1515 // For each of OP in AND/OR/XOR:
1516 // fold (OP (zext x), (zext y)) -> (zext (OP x, y))
1517 // fold (OP (sext x), (sext y)) -> (sext (OP x, y))
1518 // fold (OP (aext x), (aext y)) -> (aext (OP x, y))
1519 // fold (OP (trunc x), (trunc y)) -> (trunc (OP x, y))
1520 if ((N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND||
1521 N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::TRUNCATE) &&
1522 N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType()) {
1523 SDOperand ORNode = DAG.getNode(N->getOpcode(),
1524 N0.getOperand(0).getValueType(),
1525 N0.getOperand(0), N1.getOperand(0));
1526 AddToWorkList(ORNode.Val);
1527 return DAG.getNode(N0.getOpcode(), VT, ORNode);
1530 // For each of OP in SHL/SRL/SRA/AND...
1531 // fold (and (OP x, z), (OP y, z)) -> (OP (and x, y), z)
1532 // fold (or (OP x, z), (OP y, z)) -> (OP (or x, y), z)
1533 // fold (xor (OP x, z), (OP y, z)) -> (OP (xor x, y), z)
1534 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL ||
1535 N0.getOpcode() == ISD::SRA || N0.getOpcode() == ISD::AND) &&
1536 N0.getOperand(1) == N1.getOperand(1)) {
1537 SDOperand ORNode = DAG.getNode(N->getOpcode(),
1538 N0.getOperand(0).getValueType(),
1539 N0.getOperand(0), N1.getOperand(0));
1540 AddToWorkList(ORNode.Val);
1541 return DAG.getNode(N0.getOpcode(), VT, ORNode, N0.getOperand(1));
1547 SDOperand DAGCombiner::visitAND(SDNode *N) {
1548 SDOperand N0 = N->getOperand(0);
1549 SDOperand N1 = N->getOperand(1);
1550 SDOperand LL, LR, RL, RR, CC0, CC1;
1551 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1552 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1553 MVT::ValueType VT = N1.getValueType();
1556 if (MVT::isVector(VT)) {
1557 SDOperand FoldedVOp = SimplifyVBinOp(N);
1558 if (FoldedVOp.Val) return FoldedVOp;
1561 // fold (and x, undef) -> 0
1562 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
1563 return DAG.getConstant(0, VT);
1564 // fold (and c1, c2) -> c1&c2
1566 return DAG.getNode(ISD::AND, VT, N0, N1);
1567 // canonicalize constant to RHS
1569 return DAG.getNode(ISD::AND, VT, N1, N0);
1570 // fold (and x, -1) -> x
1571 if (N1C && N1C->isAllOnesValue())
1573 // if (and x, c) is known to be zero, return 0
1574 if (N1C && DAG.MaskedValueIsZero(SDOperand(N, 0), MVT::getIntVTBitMask(VT)))
1575 return DAG.getConstant(0, VT);
1577 SDOperand RAND = ReassociateOps(ISD::AND, N0, N1);
1580 // fold (and (or x, 0xFFFF), 0xFF) -> 0xFF
1581 if (N1C && N0.getOpcode() == ISD::OR)
1582 if (ConstantSDNode *ORI = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
1583 if ((ORI->getValue() & N1C->getValue()) == N1C->getValue())
1585 // fold (and (any_ext V), c) -> (zero_ext V) if 'and' only clears top bits.
1586 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
1587 unsigned InMask = MVT::getIntVTBitMask(N0.getOperand(0).getValueType());
1588 if (DAG.MaskedValueIsZero(N0.getOperand(0),
1589 ~N1C->getValue() & InMask)) {
1590 SDOperand Zext = DAG.getNode(ISD::ZERO_EXTEND, N0.getValueType(),
1593 // Replace uses of the AND with uses of the Zero extend node.
1596 // We actually want to replace all uses of the any_extend with the
1597 // zero_extend, to avoid duplicating things. This will later cause this
1598 // AND to be folded.
1599 CombineTo(N0.Val, Zext);
1600 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1603 // fold (and (setcc x), (setcc y)) -> (setcc (and x, y))
1604 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
1605 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
1606 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
1608 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
1609 MVT::isInteger(LL.getValueType())) {
1610 // fold (X == 0) & (Y == 0) -> (X|Y == 0)
1611 if (cast<ConstantSDNode>(LR)->getValue() == 0 && Op1 == ISD::SETEQ) {
1612 SDOperand ORNode = DAG.getNode(ISD::OR, LR.getValueType(), LL, RL);
1613 AddToWorkList(ORNode.Val);
1614 return DAG.getSetCC(VT, ORNode, LR, Op1);
1616 // fold (X == -1) & (Y == -1) -> (X&Y == -1)
1617 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETEQ) {
1618 SDOperand ANDNode = DAG.getNode(ISD::AND, LR.getValueType(), LL, RL);
1619 AddToWorkList(ANDNode.Val);
1620 return DAG.getSetCC(VT, ANDNode, LR, Op1);
1622 // fold (X > -1) & (Y > -1) -> (X|Y > -1)
1623 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETGT) {
1624 SDOperand ORNode = DAG.getNode(ISD::OR, LR.getValueType(), LL, RL);
1625 AddToWorkList(ORNode.Val);
1626 return DAG.getSetCC(VT, ORNode, LR, Op1);
1629 // canonicalize equivalent to ll == rl
1630 if (LL == RR && LR == RL) {
1631 Op1 = ISD::getSetCCSwappedOperands(Op1);
1634 if (LL == RL && LR == RR) {
1635 bool isInteger = MVT::isInteger(LL.getValueType());
1636 ISD::CondCode Result = ISD::getSetCCAndOperation(Op0, Op1, isInteger);
1637 if (Result != ISD::SETCC_INVALID)
1638 return DAG.getSetCC(N0.getValueType(), LL, LR, Result);
1642 // Simplify: and (op x...), (op y...) -> (op (and x, y))
1643 if (N0.getOpcode() == N1.getOpcode()) {
1644 SDOperand Tmp = SimplifyBinOpWithSameOpcodeHands(N);
1645 if (Tmp.Val) return Tmp;
1648 // fold (and (sign_extend_inreg x, i16 to i32), 1) -> (and x, 1)
1649 // fold (and (sra)) -> (and (srl)) when possible.
1650 if (!MVT::isVector(VT) &&
1651 SimplifyDemandedBits(SDOperand(N, 0)))
1652 return SDOperand(N, 0);
1653 // fold (zext_inreg (extload x)) -> (zextload x)
1654 if (ISD::isEXTLoad(N0.Val) && ISD::isUNINDEXEDLoad(N0.Val)) {
1655 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
1656 MVT::ValueType EVT = LN0->getLoadedVT();
1657 // If we zero all the possible extended bits, then we can turn this into
1658 // a zextload if we are running before legalize or the operation is legal.
1659 if (DAG.MaskedValueIsZero(N1, ~0ULL << MVT::getSizeInBits(EVT)) &&
1660 (!AfterLegalize || TLI.isLoadXLegal(ISD::ZEXTLOAD, EVT))) {
1661 SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(),
1662 LN0->getBasePtr(), LN0->getSrcValue(),
1663 LN0->getSrcValueOffset(), EVT,
1665 LN0->getAlignment());
1667 CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
1668 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1671 // fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use
1672 if (ISD::isSEXTLoad(N0.Val) && ISD::isUNINDEXEDLoad(N0.Val) &&
1674 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
1675 MVT::ValueType EVT = LN0->getLoadedVT();
1676 // If we zero all the possible extended bits, then we can turn this into
1677 // a zextload if we are running before legalize or the operation is legal.
1678 if (DAG.MaskedValueIsZero(N1, ~0ULL << MVT::getSizeInBits(EVT)) &&
1679 (!AfterLegalize || TLI.isLoadXLegal(ISD::ZEXTLOAD, EVT))) {
1680 SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(),
1681 LN0->getBasePtr(), LN0->getSrcValue(),
1682 LN0->getSrcValueOffset(), EVT,
1684 LN0->getAlignment());
1686 CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
1687 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1691 // fold (and (load x), 255) -> (zextload x, i8)
1692 // fold (and (extload x, i16), 255) -> (zextload x, i8)
1693 if (N1C && N0.getOpcode() == ISD::LOAD) {
1694 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
1695 if (LN0->getExtensionType() != ISD::SEXTLOAD &&
1696 LN0->getAddressingMode() == ISD::UNINDEXED &&
1698 MVT::ValueType EVT, LoadedVT;
1699 if (N1C->getValue() == 255)
1701 else if (N1C->getValue() == 65535)
1703 else if (N1C->getValue() == ~0U)
1708 LoadedVT = LN0->getLoadedVT();
1709 if (EVT != MVT::Other && LoadedVT > EVT &&
1710 (!AfterLegalize || TLI.isLoadXLegal(ISD::ZEXTLOAD, EVT))) {
1711 MVT::ValueType PtrType = N0.getOperand(1).getValueType();
1712 // For big endian targets, we need to add an offset to the pointer to
1713 // load the correct bytes. For little endian systems, we merely need to
1714 // read fewer bytes from the same pointer.
1716 (MVT::getSizeInBits(LoadedVT) - MVT::getSizeInBits(EVT)) / 8;
1717 unsigned Alignment = LN0->getAlignment();
1718 SDOperand NewPtr = LN0->getBasePtr();
1719 if (!TLI.isLittleEndian()) {
1720 NewPtr = DAG.getNode(ISD::ADD, PtrType, NewPtr,
1721 DAG.getConstant(PtrOff, PtrType));
1722 Alignment = MinAlign(Alignment, PtrOff);
1724 AddToWorkList(NewPtr.Val);
1726 DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(), NewPtr,
1727 LN0->getSrcValue(), LN0->getSrcValueOffset(), EVT,
1728 LN0->isVolatile(), Alignment);
1730 CombineTo(N0.Val, Load, Load.getValue(1));
1731 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1739 SDOperand DAGCombiner::visitOR(SDNode *N) {
1740 SDOperand N0 = N->getOperand(0);
1741 SDOperand N1 = N->getOperand(1);
1742 SDOperand LL, LR, RL, RR, CC0, CC1;
1743 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1744 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1745 MVT::ValueType VT = N1.getValueType();
1746 unsigned OpSizeInBits = MVT::getSizeInBits(VT);
1749 if (MVT::isVector(VT)) {
1750 SDOperand FoldedVOp = SimplifyVBinOp(N);
1751 if (FoldedVOp.Val) return FoldedVOp;
1754 // fold (or x, undef) -> -1
1755 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
1756 return DAG.getConstant(~0ULL, VT);
1757 // fold (or c1, c2) -> c1|c2
1759 return DAG.getNode(ISD::OR, VT, N0, N1);
1760 // canonicalize constant to RHS
1762 return DAG.getNode(ISD::OR, VT, N1, N0);
1763 // fold (or x, 0) -> x
1764 if (N1C && N1C->isNullValue())
1766 // fold (or x, -1) -> -1
1767 if (N1C && N1C->isAllOnesValue())
1769 // fold (or x, c) -> c iff (x & ~c) == 0
1771 DAG.MaskedValueIsZero(N0,~N1C->getValue() & (~0ULL>>(64-OpSizeInBits))))
1774 SDOperand ROR = ReassociateOps(ISD::OR, N0, N1);
1777 // Canonicalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2)
1778 if (N1C && N0.getOpcode() == ISD::AND && N0.Val->hasOneUse() &&
1779 isa<ConstantSDNode>(N0.getOperand(1))) {
1780 ConstantSDNode *C1 = cast<ConstantSDNode>(N0.getOperand(1));
1781 return DAG.getNode(ISD::AND, VT, DAG.getNode(ISD::OR, VT, N0.getOperand(0),
1783 DAG.getConstant(N1C->getValue() | C1->getValue(), VT));
1785 // fold (or (setcc x), (setcc y)) -> (setcc (or x, y))
1786 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
1787 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
1788 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
1790 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
1791 MVT::isInteger(LL.getValueType())) {
1792 // fold (X != 0) | (Y != 0) -> (X|Y != 0)
1793 // fold (X < 0) | (Y < 0) -> (X|Y < 0)
1794 if (cast<ConstantSDNode>(LR)->getValue() == 0 &&
1795 (Op1 == ISD::SETNE || Op1 == ISD::SETLT)) {
1796 SDOperand ORNode = DAG.getNode(ISD::OR, LR.getValueType(), LL, RL);
1797 AddToWorkList(ORNode.Val);
1798 return DAG.getSetCC(VT, ORNode, LR, Op1);
1800 // fold (X != -1) | (Y != -1) -> (X&Y != -1)
1801 // fold (X > -1) | (Y > -1) -> (X&Y > -1)
1802 if (cast<ConstantSDNode>(LR)->isAllOnesValue() &&
1803 (Op1 == ISD::SETNE || Op1 == ISD::SETGT)) {
1804 SDOperand ANDNode = DAG.getNode(ISD::AND, LR.getValueType(), LL, RL);
1805 AddToWorkList(ANDNode.Val);
1806 return DAG.getSetCC(VT, ANDNode, LR, Op1);
1809 // canonicalize equivalent to ll == rl
1810 if (LL == RR && LR == RL) {
1811 Op1 = ISD::getSetCCSwappedOperands(Op1);
1814 if (LL == RL && LR == RR) {
1815 bool isInteger = MVT::isInteger(LL.getValueType());
1816 ISD::CondCode Result = ISD::getSetCCOrOperation(Op0, Op1, isInteger);
1817 if (Result != ISD::SETCC_INVALID)
1818 return DAG.getSetCC(N0.getValueType(), LL, LR, Result);
1822 // Simplify: or (op x...), (op y...) -> (op (or x, y))
1823 if (N0.getOpcode() == N1.getOpcode()) {
1824 SDOperand Tmp = SimplifyBinOpWithSameOpcodeHands(N);
1825 if (Tmp.Val) return Tmp;
1828 // (X & C1) | (Y & C2) -> (X|Y) & C3 if possible.
1829 if (N0.getOpcode() == ISD::AND &&
1830 N1.getOpcode() == ISD::AND &&
1831 N0.getOperand(1).getOpcode() == ISD::Constant &&
1832 N1.getOperand(1).getOpcode() == ISD::Constant &&
1833 // Don't increase # computations.
1834 (N0.Val->hasOneUse() || N1.Val->hasOneUse())) {
1835 // We can only do this xform if we know that bits from X that are set in C2
1836 // but not in C1 are already zero. Likewise for Y.
1837 uint64_t LHSMask = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
1838 uint64_t RHSMask = cast<ConstantSDNode>(N1.getOperand(1))->getValue();
1840 if (DAG.MaskedValueIsZero(N0.getOperand(0), RHSMask&~LHSMask) &&
1841 DAG.MaskedValueIsZero(N1.getOperand(0), LHSMask&~RHSMask)) {
1842 SDOperand X =DAG.getNode(ISD::OR, VT, N0.getOperand(0), N1.getOperand(0));
1843 return DAG.getNode(ISD::AND, VT, X, DAG.getConstant(LHSMask|RHSMask, VT));
1848 // See if this is some rotate idiom.
1849 if (SDNode *Rot = MatchRotate(N0, N1))
1850 return SDOperand(Rot, 0);
1856 /// MatchRotateHalf - Match "(X shl/srl V1) & V2" where V2 may not be present.
1857 static bool MatchRotateHalf(SDOperand Op, SDOperand &Shift, SDOperand &Mask) {
1858 if (Op.getOpcode() == ISD::AND) {
1859 if (isa<ConstantSDNode>(Op.getOperand(1))) {
1860 Mask = Op.getOperand(1);
1861 Op = Op.getOperand(0);
1867 if (Op.getOpcode() == ISD::SRL || Op.getOpcode() == ISD::SHL) {
1875 // MatchRotate - Handle an 'or' of two operands. If this is one of the many
1876 // idioms for rotate, and if the target supports rotation instructions, generate
1878 SDNode *DAGCombiner::MatchRotate(SDOperand LHS, SDOperand RHS) {
1879 // Must be a legal type. Expanded an promoted things won't work with rotates.
1880 MVT::ValueType VT = LHS.getValueType();
1881 if (!TLI.isTypeLegal(VT)) return 0;
1883 // The target must have at least one rotate flavor.
1884 bool HasROTL = TLI.isOperationLegal(ISD::ROTL, VT);
1885 bool HasROTR = TLI.isOperationLegal(ISD::ROTR, VT);
1886 if (!HasROTL && !HasROTR) return 0;
1888 // Match "(X shl/srl V1) & V2" where V2 may not be present.
1889 SDOperand LHSShift; // The shift.
1890 SDOperand LHSMask; // AND value if any.
1891 if (!MatchRotateHalf(LHS, LHSShift, LHSMask))
1892 return 0; // Not part of a rotate.
1894 SDOperand RHSShift; // The shift.
1895 SDOperand RHSMask; // AND value if any.
1896 if (!MatchRotateHalf(RHS, RHSShift, RHSMask))
1897 return 0; // Not part of a rotate.
1899 if (LHSShift.getOperand(0) != RHSShift.getOperand(0))
1900 return 0; // Not shifting the same value.
1902 if (LHSShift.getOpcode() == RHSShift.getOpcode())
1903 return 0; // Shifts must disagree.
1905 // Canonicalize shl to left side in a shl/srl pair.
1906 if (RHSShift.getOpcode() == ISD::SHL) {
1907 std::swap(LHS, RHS);
1908 std::swap(LHSShift, RHSShift);
1909 std::swap(LHSMask , RHSMask );
1912 unsigned OpSizeInBits = MVT::getSizeInBits(VT);
1913 SDOperand LHSShiftArg = LHSShift.getOperand(0);
1914 SDOperand LHSShiftAmt = LHSShift.getOperand(1);
1915 SDOperand RHSShiftAmt = RHSShift.getOperand(1);
1917 // fold (or (shl x, C1), (srl x, C2)) -> (rotl x, C1)
1918 // fold (or (shl x, C1), (srl x, C2)) -> (rotr x, C2)
1919 if (LHSShiftAmt.getOpcode() == ISD::Constant &&
1920 RHSShiftAmt.getOpcode() == ISD::Constant) {
1921 uint64_t LShVal = cast<ConstantSDNode>(LHSShiftAmt)->getValue();
1922 uint64_t RShVal = cast<ConstantSDNode>(RHSShiftAmt)->getValue();
1923 if ((LShVal + RShVal) != OpSizeInBits)
1928 Rot = DAG.getNode(ISD::ROTL, VT, LHSShiftArg, LHSShiftAmt);
1930 Rot = DAG.getNode(ISD::ROTR, VT, LHSShiftArg, RHSShiftAmt);
1932 // If there is an AND of either shifted operand, apply it to the result.
1933 if (LHSMask.Val || RHSMask.Val) {
1934 uint64_t Mask = MVT::getIntVTBitMask(VT);
1937 uint64_t RHSBits = (1ULL << LShVal)-1;
1938 Mask &= cast<ConstantSDNode>(LHSMask)->getValue() | RHSBits;
1941 uint64_t LHSBits = ~((1ULL << (OpSizeInBits-RShVal))-1);
1942 Mask &= cast<ConstantSDNode>(RHSMask)->getValue() | LHSBits;
1945 Rot = DAG.getNode(ISD::AND, VT, Rot, DAG.getConstant(Mask, VT));
1951 // If there is a mask here, and we have a variable shift, we can't be sure
1952 // that we're masking out the right stuff.
1953 if (LHSMask.Val || RHSMask.Val)
1956 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotl x, y)
1957 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotr x, (sub 32, y))
1958 if (RHSShiftAmt.getOpcode() == ISD::SUB &&
1959 LHSShiftAmt == RHSShiftAmt.getOperand(1)) {
1960 if (ConstantSDNode *SUBC =
1961 dyn_cast<ConstantSDNode>(RHSShiftAmt.getOperand(0))) {
1962 if (SUBC->getValue() == OpSizeInBits)
1964 return DAG.getNode(ISD::ROTL, VT, LHSShiftArg, LHSShiftAmt).Val;
1966 return DAG.getNode(ISD::ROTR, VT, LHSShiftArg, RHSShiftAmt).Val;
1970 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotr x, y)
1971 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotl x, (sub 32, y))
1972 if (LHSShiftAmt.getOpcode() == ISD::SUB &&
1973 RHSShiftAmt == LHSShiftAmt.getOperand(1)) {
1974 if (ConstantSDNode *SUBC =
1975 dyn_cast<ConstantSDNode>(LHSShiftAmt.getOperand(0))) {
1976 if (SUBC->getValue() == OpSizeInBits)
1978 return DAG.getNode(ISD::ROTL, VT, LHSShiftArg, LHSShiftAmt).Val;
1980 return DAG.getNode(ISD::ROTR, VT, LHSShiftArg, RHSShiftAmt).Val;
1984 // Look for sign/zext/any-extended cases:
1985 if ((LHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND
1986 || LHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND
1987 || LHSShiftAmt.getOpcode() == ISD::ANY_EXTEND) &&
1988 (RHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND
1989 || RHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND
1990 || RHSShiftAmt.getOpcode() == ISD::ANY_EXTEND)) {
1991 SDOperand LExtOp0 = LHSShiftAmt.getOperand(0);
1992 SDOperand RExtOp0 = RHSShiftAmt.getOperand(0);
1993 if (RExtOp0.getOpcode() == ISD::SUB &&
1994 RExtOp0.getOperand(1) == LExtOp0) {
1995 // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
1997 // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
1998 // (rotl x, (sub 32, y))
1999 if (ConstantSDNode *SUBC = cast<ConstantSDNode>(RExtOp0.getOperand(0))) {
2000 if (SUBC->getValue() == OpSizeInBits) {
2002 return DAG.getNode(ISD::ROTL, VT, LHSShiftArg, LHSShiftAmt).Val;
2004 return DAG.getNode(ISD::ROTR, VT, LHSShiftArg, RHSShiftAmt).Val;
2007 } else if (LExtOp0.getOpcode() == ISD::SUB &&
2008 RExtOp0 == LExtOp0.getOperand(1)) {
2009 // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext r))) ->
2011 // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext r))) ->
2012 // (rotr x, (sub 32, y))
2013 if (ConstantSDNode *SUBC = cast<ConstantSDNode>(LExtOp0.getOperand(0))) {
2014 if (SUBC->getValue() == OpSizeInBits) {
2016 return DAG.getNode(ISD::ROTL, VT, LHSShiftArg, RHSShiftAmt).Val;
2018 return DAG.getNode(ISD::ROTL, VT, LHSShiftArg, LHSShiftAmt).Val;
2028 SDOperand DAGCombiner::visitXOR(SDNode *N) {
2029 SDOperand N0 = N->getOperand(0);
2030 SDOperand N1 = N->getOperand(1);
2031 SDOperand LHS, RHS, CC;
2032 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2033 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2034 MVT::ValueType VT = N0.getValueType();
2037 if (MVT::isVector(VT)) {
2038 SDOperand FoldedVOp = SimplifyVBinOp(N);
2039 if (FoldedVOp.Val) return FoldedVOp;
2042 // fold (xor x, undef) -> undef
2043 if (N0.getOpcode() == ISD::UNDEF)
2045 if (N1.getOpcode() == ISD::UNDEF)
2047 // fold (xor c1, c2) -> c1^c2
2049 return DAG.getNode(ISD::XOR, VT, N0, N1);
2050 // canonicalize constant to RHS
2052 return DAG.getNode(ISD::XOR, VT, N1, N0);
2053 // fold (xor x, 0) -> x
2054 if (N1C && N1C->isNullValue())
2057 SDOperand RXOR = ReassociateOps(ISD::XOR, N0, N1);
2060 // fold !(x cc y) -> (x !cc y)
2061 if (N1C && N1C->getValue() == 1 && isSetCCEquivalent(N0, LHS, RHS, CC)) {
2062 bool isInt = MVT::isInteger(LHS.getValueType());
2063 ISD::CondCode NotCC = ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
2065 if (N0.getOpcode() == ISD::SETCC)
2066 return DAG.getSetCC(VT, LHS, RHS, NotCC);
2067 if (N0.getOpcode() == ISD::SELECT_CC)
2068 return DAG.getSelectCC(LHS, RHS, N0.getOperand(2),N0.getOperand(3),NotCC);
2069 assert(0 && "Unhandled SetCC Equivalent!");
2072 // fold (not (zext (setcc x, y))) -> (zext (not (setcc x, y)))
2073 if (N1C && N1C->getValue() == 1 && N0.getOpcode() == ISD::ZERO_EXTEND &&
2074 N0.Val->hasOneUse() && isSetCCEquivalent(N0.getOperand(0), LHS, RHS, CC)){
2075 SDOperand V = N0.getOperand(0);
2076 V = DAG.getNode(ISD::XOR, V.getValueType(), V,
2077 DAG.getConstant(1, V.getValueType()));
2078 AddToWorkList(V.Val);
2079 return DAG.getNode(ISD::ZERO_EXTEND, VT, V);
2082 // fold !(x or y) -> (!x and !y) iff x or y are setcc
2083 if (N1C && N1C->getValue() == 1 && VT == MVT::i1 &&
2084 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
2085 SDOperand LHS = N0.getOperand(0), RHS = N0.getOperand(1);
2086 if (isOneUseSetCC(RHS) || isOneUseSetCC(LHS)) {
2087 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
2088 LHS = DAG.getNode(ISD::XOR, VT, LHS, N1); // RHS = ~LHS
2089 RHS = DAG.getNode(ISD::XOR, VT, RHS, N1); // RHS = ~RHS
2090 AddToWorkList(LHS.Val); AddToWorkList(RHS.Val);
2091 return DAG.getNode(NewOpcode, VT, LHS, RHS);
2094 // fold !(x or y) -> (!x and !y) iff x or y are constants
2095 if (N1C && N1C->isAllOnesValue() &&
2096 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
2097 SDOperand LHS = N0.getOperand(0), RHS = N0.getOperand(1);
2098 if (isa<ConstantSDNode>(RHS) || isa<ConstantSDNode>(LHS)) {
2099 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
2100 LHS = DAG.getNode(ISD::XOR, VT, LHS, N1); // RHS = ~LHS
2101 RHS = DAG.getNode(ISD::XOR, VT, RHS, N1); // RHS = ~RHS
2102 AddToWorkList(LHS.Val); AddToWorkList(RHS.Val);
2103 return DAG.getNode(NewOpcode, VT, LHS, RHS);
2106 // fold (xor (xor x, c1), c2) -> (xor x, c1^c2)
2107 if (N1C && N0.getOpcode() == ISD::XOR) {
2108 ConstantSDNode *N00C = dyn_cast<ConstantSDNode>(N0.getOperand(0));
2109 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2111 return DAG.getNode(ISD::XOR, VT, N0.getOperand(1),
2112 DAG.getConstant(N1C->getValue()^N00C->getValue(), VT));
2114 return DAG.getNode(ISD::XOR, VT, N0.getOperand(0),
2115 DAG.getConstant(N1C->getValue()^N01C->getValue(), VT));
2117 // fold (xor x, x) -> 0
2119 if (!MVT::isVector(VT)) {
2120 return DAG.getConstant(0, VT);
2121 } else if (!AfterLegalize || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)) {
2122 // Produce a vector of zeros.
2123 SDOperand El = DAG.getConstant(0, MVT::getVectorElementType(VT));
2124 std::vector<SDOperand> Ops(MVT::getVectorNumElements(VT), El);
2125 return DAG.getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size());
2129 // Simplify: xor (op x...), (op y...) -> (op (xor x, y))
2130 if (N0.getOpcode() == N1.getOpcode()) {
2131 SDOperand Tmp = SimplifyBinOpWithSameOpcodeHands(N);
2132 if (Tmp.Val) return Tmp;
2135 // Simplify the expression using non-local knowledge.
2136 if (!MVT::isVector(VT) &&
2137 SimplifyDemandedBits(SDOperand(N, 0)))
2138 return SDOperand(N, 0);
2143 SDOperand DAGCombiner::visitSHL(SDNode *N) {
2144 SDOperand N0 = N->getOperand(0);
2145 SDOperand N1 = N->getOperand(1);
2146 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2147 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2148 MVT::ValueType VT = N0.getValueType();
2149 unsigned OpSizeInBits = MVT::getSizeInBits(VT);
2151 // fold (shl c1, c2) -> c1<<c2
2153 return DAG.getNode(ISD::SHL, VT, N0, N1);
2154 // fold (shl 0, x) -> 0
2155 if (N0C && N0C->isNullValue())
2157 // fold (shl x, c >= size(x)) -> undef
2158 if (N1C && N1C->getValue() >= OpSizeInBits)
2159 return DAG.getNode(ISD::UNDEF, VT);
2160 // fold (shl x, 0) -> x
2161 if (N1C && N1C->isNullValue())
2163 // if (shl x, c) is known to be zero, return 0
2164 if (DAG.MaskedValueIsZero(SDOperand(N, 0), MVT::getIntVTBitMask(VT)))
2165 return DAG.getConstant(0, VT);
2166 if (N1C && SimplifyDemandedBits(SDOperand(N, 0)))
2167 return SDOperand(N, 0);
2168 // fold (shl (shl x, c1), c2) -> 0 or (shl x, c1+c2)
2169 if (N1C && N0.getOpcode() == ISD::SHL &&
2170 N0.getOperand(1).getOpcode() == ISD::Constant) {
2171 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
2172 uint64_t c2 = N1C->getValue();
2173 if (c1 + c2 > OpSizeInBits)
2174 return DAG.getConstant(0, VT);
2175 return DAG.getNode(ISD::SHL, VT, N0.getOperand(0),
2176 DAG.getConstant(c1 + c2, N1.getValueType()));
2178 // fold (shl (srl x, c1), c2) -> (shl (and x, -1 << c1), c2-c1) or
2179 // (srl (and x, -1 << c1), c1-c2)
2180 if (N1C && N0.getOpcode() == ISD::SRL &&
2181 N0.getOperand(1).getOpcode() == ISD::Constant) {
2182 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
2183 uint64_t c2 = N1C->getValue();
2184 SDOperand Mask = DAG.getNode(ISD::AND, VT, N0.getOperand(0),
2185 DAG.getConstant(~0ULL << c1, VT));
2187 return DAG.getNode(ISD::SHL, VT, Mask,
2188 DAG.getConstant(c2-c1, N1.getValueType()));
2190 return DAG.getNode(ISD::SRL, VT, Mask,
2191 DAG.getConstant(c1-c2, N1.getValueType()));
2193 // fold (shl (sra x, c1), c1) -> (and x, -1 << c1)
2194 if (N1C && N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1))
2195 return DAG.getNode(ISD::AND, VT, N0.getOperand(0),
2196 DAG.getConstant(~0ULL << N1C->getValue(), VT));
2200 SDOperand DAGCombiner::visitSRA(SDNode *N) {
2201 SDOperand N0 = N->getOperand(0);
2202 SDOperand N1 = N->getOperand(1);
2203 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2204 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2205 MVT::ValueType VT = N0.getValueType();
2207 // fold (sra c1, c2) -> c1>>c2
2209 return DAG.getNode(ISD::SRA, VT, N0, N1);
2210 // fold (sra 0, x) -> 0
2211 if (N0C && N0C->isNullValue())
2213 // fold (sra -1, x) -> -1
2214 if (N0C && N0C->isAllOnesValue())
2216 // fold (sra x, c >= size(x)) -> undef
2217 if (N1C && N1C->getValue() >= MVT::getSizeInBits(VT))
2218 return DAG.getNode(ISD::UNDEF, VT);
2219 // fold (sra x, 0) -> x
2220 if (N1C && N1C->isNullValue())
2222 // fold (sra (shl x, c1), c1) -> sext_inreg for some c1 and target supports
2224 if (N1C && N0.getOpcode() == ISD::SHL && N1 == N0.getOperand(1)) {
2225 unsigned LowBits = MVT::getSizeInBits(VT) - (unsigned)N1C->getValue();
2228 default: EVT = MVT::Other; break;
2229 case 1: EVT = MVT::i1; break;
2230 case 8: EVT = MVT::i8; break;
2231 case 16: EVT = MVT::i16; break;
2232 case 32: EVT = MVT::i32; break;
2234 if (EVT > MVT::Other && TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, EVT))
2235 return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, N0.getOperand(0),
2236 DAG.getValueType(EVT));
2239 // fold (sra (sra x, c1), c2) -> (sra x, c1+c2)
2240 if (N1C && N0.getOpcode() == ISD::SRA) {
2241 if (ConstantSDNode *C1 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
2242 unsigned Sum = N1C->getValue() + C1->getValue();
2243 if (Sum >= MVT::getSizeInBits(VT)) Sum = MVT::getSizeInBits(VT)-1;
2244 return DAG.getNode(ISD::SRA, VT, N0.getOperand(0),
2245 DAG.getConstant(Sum, N1C->getValueType(0)));
2249 // Simplify, based on bits shifted out of the LHS.
2250 if (N1C && SimplifyDemandedBits(SDOperand(N, 0)))
2251 return SDOperand(N, 0);
2254 // If the sign bit is known to be zero, switch this to a SRL.
2255 if (DAG.MaskedValueIsZero(N0, MVT::getIntVTSignBit(VT)))
2256 return DAG.getNode(ISD::SRL, VT, N0, N1);
2260 SDOperand DAGCombiner::visitSRL(SDNode *N) {
2261 SDOperand N0 = N->getOperand(0);
2262 SDOperand N1 = N->getOperand(1);
2263 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2264 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2265 MVT::ValueType VT = N0.getValueType();
2266 unsigned OpSizeInBits = MVT::getSizeInBits(VT);
2268 // fold (srl c1, c2) -> c1 >>u c2
2270 return DAG.getNode(ISD::SRL, VT, N0, N1);
2271 // fold (srl 0, x) -> 0
2272 if (N0C && N0C->isNullValue())
2274 // fold (srl x, c >= size(x)) -> undef
2275 if (N1C && N1C->getValue() >= OpSizeInBits)
2276 return DAG.getNode(ISD::UNDEF, VT);
2277 // fold (srl x, 0) -> x
2278 if (N1C && N1C->isNullValue())
2280 // if (srl x, c) is known to be zero, return 0
2281 if (N1C && DAG.MaskedValueIsZero(SDOperand(N, 0), ~0ULL >> (64-OpSizeInBits)))
2282 return DAG.getConstant(0, VT);
2284 // fold (srl (srl x, c1), c2) -> 0 or (srl x, c1+c2)
2285 if (N1C && N0.getOpcode() == ISD::SRL &&
2286 N0.getOperand(1).getOpcode() == ISD::Constant) {
2287 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
2288 uint64_t c2 = N1C->getValue();
2289 if (c1 + c2 > OpSizeInBits)
2290 return DAG.getConstant(0, VT);
2291 return DAG.getNode(ISD::SRL, VT, N0.getOperand(0),
2292 DAG.getConstant(c1 + c2, N1.getValueType()));
2295 // fold (srl (anyextend x), c) -> (anyextend (srl x, c))
2296 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
2297 // Shifting in all undef bits?
2298 MVT::ValueType SmallVT = N0.getOperand(0).getValueType();
2299 if (N1C->getValue() >= MVT::getSizeInBits(SmallVT))
2300 return DAG.getNode(ISD::UNDEF, VT);
2302 SDOperand SmallShift = DAG.getNode(ISD::SRL, SmallVT, N0.getOperand(0), N1);
2303 AddToWorkList(SmallShift.Val);
2304 return DAG.getNode(ISD::ANY_EXTEND, VT, SmallShift);
2307 // fold (srl (sra X, Y), 31) -> (srl X, 31). This srl only looks at the sign
2308 // bit, which is unmodified by sra.
2309 if (N1C && N1C->getValue()+1 == MVT::getSizeInBits(VT)) {
2310 if (N0.getOpcode() == ISD::SRA)
2311 return DAG.getNode(ISD::SRL, VT, N0.getOperand(0), N1);
2314 // fold (srl (ctlz x), "5") -> x iff x has one bit set (the low bit).
2315 if (N1C && N0.getOpcode() == ISD::CTLZ &&
2316 N1C->getValue() == Log2_32(MVT::getSizeInBits(VT))) {
2317 uint64_t KnownZero, KnownOne, Mask = MVT::getIntVTBitMask(VT);
2318 DAG.ComputeMaskedBits(N0.getOperand(0), Mask, KnownZero, KnownOne);
2320 // If any of the input bits are KnownOne, then the input couldn't be all
2321 // zeros, thus the result of the srl will always be zero.
2322 if (KnownOne) return DAG.getConstant(0, VT);
2324 // If all of the bits input the to ctlz node are known to be zero, then
2325 // the result of the ctlz is "32" and the result of the shift is one.
2326 uint64_t UnknownBits = ~KnownZero & Mask;
2327 if (UnknownBits == 0) return DAG.getConstant(1, VT);
2329 // Otherwise, check to see if there is exactly one bit input to the ctlz.
2330 if ((UnknownBits & (UnknownBits-1)) == 0) {
2331 // Okay, we know that only that the single bit specified by UnknownBits
2332 // could be set on input to the CTLZ node. If this bit is set, the SRL
2333 // will return 0, if it is clear, it returns 1. Change the CTLZ/SRL pair
2334 // to an SRL,XOR pair, which is likely to simplify more.
2335 unsigned ShAmt = CountTrailingZeros_64(UnknownBits);
2336 SDOperand Op = N0.getOperand(0);
2338 Op = DAG.getNode(ISD::SRL, VT, Op,
2339 DAG.getConstant(ShAmt, TLI.getShiftAmountTy()));
2340 AddToWorkList(Op.Val);
2342 return DAG.getNode(ISD::XOR, VT, Op, DAG.getConstant(1, VT));
2346 // fold operands of srl based on knowledge that the low bits are not
2348 if (N1C && SimplifyDemandedBits(SDOperand(N, 0)))
2349 return SDOperand(N, 0);
2354 SDOperand DAGCombiner::visitCTLZ(SDNode *N) {
2355 SDOperand N0 = N->getOperand(0);
2356 MVT::ValueType VT = N->getValueType(0);
2358 // fold (ctlz c1) -> c2
2359 if (isa<ConstantSDNode>(N0))
2360 return DAG.getNode(ISD::CTLZ, VT, N0);
2364 SDOperand DAGCombiner::visitCTTZ(SDNode *N) {
2365 SDOperand N0 = N->getOperand(0);
2366 MVT::ValueType VT = N->getValueType(0);
2368 // fold (cttz c1) -> c2
2369 if (isa<ConstantSDNode>(N0))
2370 return DAG.getNode(ISD::CTTZ, VT, N0);
2374 SDOperand DAGCombiner::visitCTPOP(SDNode *N) {
2375 SDOperand N0 = N->getOperand(0);
2376 MVT::ValueType VT = N->getValueType(0);
2378 // fold (ctpop c1) -> c2
2379 if (isa<ConstantSDNode>(N0))
2380 return DAG.getNode(ISD::CTPOP, VT, N0);
2384 SDOperand DAGCombiner::visitSELECT(SDNode *N) {
2385 SDOperand N0 = N->getOperand(0);
2386 SDOperand N1 = N->getOperand(1);
2387 SDOperand N2 = N->getOperand(2);
2388 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2389 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2390 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2);
2391 MVT::ValueType VT = N->getValueType(0);
2392 MVT::ValueType VT0 = N0.getValueType();
2394 // fold select C, X, X -> X
2397 // fold select true, X, Y -> X
2398 if (N0C && !N0C->isNullValue())
2400 // fold select false, X, Y -> Y
2401 if (N0C && N0C->isNullValue())
2403 // fold select C, 1, X -> C | X
2404 if (MVT::i1 == VT && N1C && N1C->getValue() == 1)
2405 return DAG.getNode(ISD::OR, VT, N0, N2);
2406 // fold select C, 0, 1 -> ~C
2407 if (MVT::isInteger(VT) && MVT::isInteger(VT0) &&
2408 N1C && N2C && N1C->isNullValue() && N2C->getValue() == 1) {
2409 SDOperand XORNode = DAG.getNode(ISD::XOR, VT0, N0, DAG.getConstant(1, VT0));
2412 AddToWorkList(XORNode.Val);
2413 if (MVT::getSizeInBits(VT) > MVT::getSizeInBits(VT0))
2414 return DAG.getNode(ISD::ZERO_EXTEND, VT, XORNode);
2415 return DAG.getNode(ISD::TRUNCATE, VT, XORNode);
2417 // fold select C, 0, X -> ~C & X
2418 if (VT == VT0 && N1C && N1C->isNullValue()) {
2419 SDOperand XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(1, VT));
2420 AddToWorkList(XORNode.Val);
2421 return DAG.getNode(ISD::AND, VT, XORNode, N2);
2423 // fold select C, X, 1 -> ~C | X
2424 if (VT == VT0 && N2C && N2C->getValue() == 1) {
2425 SDOperand XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(1, VT));
2426 AddToWorkList(XORNode.Val);
2427 return DAG.getNode(ISD::OR, VT, XORNode, N1);
2429 // fold select C, X, 0 -> C & X
2430 // FIXME: this should check for C type == X type, not i1?
2431 if (MVT::i1 == VT && N2C && N2C->isNullValue())
2432 return DAG.getNode(ISD::AND, VT, N0, N1);
2433 // fold X ? X : Y --> X ? 1 : Y --> X | Y
2434 if (MVT::i1 == VT && N0 == N1)
2435 return DAG.getNode(ISD::OR, VT, N0, N2);
2436 // fold X ? Y : X --> X ? Y : 0 --> X & Y
2437 if (MVT::i1 == VT && N0 == N2)
2438 return DAG.getNode(ISD::AND, VT, N0, N1);
2440 // If we can fold this based on the true/false value, do so.
2441 if (SimplifySelectOps(N, N1, N2))
2442 return SDOperand(N, 0); // Don't revisit N.
2444 // fold selects based on a setcc into other things, such as min/max/abs
2445 if (N0.getOpcode() == ISD::SETCC)
2447 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
2448 // having to say they don't support SELECT_CC on every type the DAG knows
2449 // about, since there is no way to mark an opcode illegal at all value types
2450 if (TLI.isOperationLegal(ISD::SELECT_CC, MVT::Other))
2451 return DAG.getNode(ISD::SELECT_CC, VT, N0.getOperand(0), N0.getOperand(1),
2452 N1, N2, N0.getOperand(2));
2454 return SimplifySelect(N0, N1, N2);
2458 SDOperand DAGCombiner::visitSELECT_CC(SDNode *N) {
2459 SDOperand N0 = N->getOperand(0);
2460 SDOperand N1 = N->getOperand(1);
2461 SDOperand N2 = N->getOperand(2);
2462 SDOperand N3 = N->getOperand(3);
2463 SDOperand N4 = N->getOperand(4);
2464 ISD::CondCode CC = cast<CondCodeSDNode>(N4)->get();
2466 // fold select_cc lhs, rhs, x, x, cc -> x
2470 // Determine if the condition we're dealing with is constant
2471 SDOperand SCC = SimplifySetCC(TLI.getSetCCResultTy(), N0, N1, CC, false);
2472 if (SCC.Val) AddToWorkList(SCC.Val);
2474 if (ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.Val)) {
2475 if (SCCC->getValue())
2476 return N2; // cond always true -> true val
2478 return N3; // cond always false -> false val
2481 // Fold to a simpler select_cc
2482 if (SCC.Val && SCC.getOpcode() == ISD::SETCC)
2483 return DAG.getNode(ISD::SELECT_CC, N2.getValueType(),
2484 SCC.getOperand(0), SCC.getOperand(1), N2, N3,
2487 // If we can fold this based on the true/false value, do so.
2488 if (SimplifySelectOps(N, N2, N3))
2489 return SDOperand(N, 0); // Don't revisit N.
2491 // fold select_cc into other things, such as min/max/abs
2492 return SimplifySelectCC(N0, N1, N2, N3, CC);
2495 SDOperand DAGCombiner::visitSETCC(SDNode *N) {
2496 return SimplifySetCC(N->getValueType(0), N->getOperand(0), N->getOperand(1),
2497 cast<CondCodeSDNode>(N->getOperand(2))->get());
2500 // ExtendUsesToFormExtLoad - Trying to extend uses of a load to enable this:
2501 // "fold ({s|z}ext (load x)) -> ({s|z}ext (truncate ({s|z}extload x)))"
2502 // transformation. Returns true if extension are possible and the above
2503 // mentioned transformation is profitable.
2504 static bool ExtendUsesToFormExtLoad(SDNode *N, SDOperand N0,
2506 SmallVector<SDNode*, 4> &ExtendNodes,
2507 TargetLowering &TLI) {
2508 bool HasCopyToRegUses = false;
2509 bool isTruncFree = TLI.isTruncateFree(N->getValueType(0), N0.getValueType());
2510 for (SDNode::use_iterator UI = N0.Val->use_begin(), UE = N0.Val->use_end();
2515 // FIXME: Only extend SETCC N, N and SETCC N, c for now.
2516 if (User->getOpcode() == ISD::SETCC) {
2517 ISD::CondCode CC = cast<CondCodeSDNode>(User->getOperand(2))->get();
2518 if (ExtOpc == ISD::ZERO_EXTEND && ISD::isSignedIntSetCC(CC))
2519 // Sign bits will be lost after a zext.
2522 for (unsigned i = 0; i != 2; ++i) {
2523 SDOperand UseOp = User->getOperand(i);
2526 if (!isa<ConstantSDNode>(UseOp))
2531 ExtendNodes.push_back(User);
2533 for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) {
2534 SDOperand UseOp = User->getOperand(i);
2536 // If truncate from extended type to original load type is free
2537 // on this target, then it's ok to extend a CopyToReg.
2538 if (isTruncFree && User->getOpcode() == ISD::CopyToReg)
2539 HasCopyToRegUses = true;
2547 if (HasCopyToRegUses) {
2548 bool BothLiveOut = false;
2549 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
2552 for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) {
2553 SDOperand UseOp = User->getOperand(i);
2554 if (UseOp.Val == N && UseOp.ResNo == 0) {
2561 // Both unextended and extended values are live out. There had better be
2562 // good a reason for the transformation.
2563 return ExtendNodes.size();
2568 SDOperand DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
2569 SDOperand N0 = N->getOperand(0);
2570 MVT::ValueType VT = N->getValueType(0);
2572 // fold (sext c1) -> c1
2573 if (isa<ConstantSDNode>(N0))
2574 return DAG.getNode(ISD::SIGN_EXTEND, VT, N0);
2576 // fold (sext (sext x)) -> (sext x)
2577 // fold (sext (aext x)) -> (sext x)
2578 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
2579 return DAG.getNode(ISD::SIGN_EXTEND, VT, N0.getOperand(0));
2581 // fold (sext (truncate (load x))) -> (sext (smaller load x))
2582 // fold (sext (truncate (srl (load x), c))) -> (sext (smaller load (x+c/n)))
2583 if (N0.getOpcode() == ISD::TRUNCATE) {
2584 SDOperand NarrowLoad = ReduceLoadWidth(N0.Val);
2585 if (NarrowLoad.Val) {
2586 if (NarrowLoad.Val != N0.Val)
2587 CombineTo(N0.Val, NarrowLoad);
2588 return DAG.getNode(ISD::SIGN_EXTEND, VT, NarrowLoad);
2592 // See if the value being truncated is already sign extended. If so, just
2593 // eliminate the trunc/sext pair.
2594 if (N0.getOpcode() == ISD::TRUNCATE) {
2595 SDOperand Op = N0.getOperand(0);
2596 unsigned OpBits = MVT::getSizeInBits(Op.getValueType());
2597 unsigned MidBits = MVT::getSizeInBits(N0.getValueType());
2598 unsigned DestBits = MVT::getSizeInBits(VT);
2599 unsigned NumSignBits = DAG.ComputeNumSignBits(Op);
2601 if (OpBits == DestBits) {
2602 // Op is i32, Mid is i8, and Dest is i32. If Op has more than 24 sign
2603 // bits, it is already ready.
2604 if (NumSignBits > DestBits-MidBits)
2606 } else if (OpBits < DestBits) {
2607 // Op is i32, Mid is i8, and Dest is i64. If Op has more than 24 sign
2608 // bits, just sext from i32.
2609 if (NumSignBits > OpBits-MidBits)
2610 return DAG.getNode(ISD::SIGN_EXTEND, VT, Op);
2612 // Op is i64, Mid is i8, and Dest is i32. If Op has more than 56 sign
2613 // bits, just truncate to i32.
2614 if (NumSignBits > OpBits-MidBits)
2615 return DAG.getNode(ISD::TRUNCATE, VT, Op);
2618 // fold (sext (truncate x)) -> (sextinreg x).
2619 if (!AfterLegalize || TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG,
2620 N0.getValueType())) {
2621 if (Op.getValueType() < VT)
2622 Op = DAG.getNode(ISD::ANY_EXTEND, VT, Op);
2623 else if (Op.getValueType() > VT)
2624 Op = DAG.getNode(ISD::TRUNCATE, VT, Op);
2625 return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, Op,
2626 DAG.getValueType(N0.getValueType()));
2630 // fold (sext (load x)) -> (sext (truncate (sextload x)))
2631 if (ISD::isNON_EXTLoad(N0.Val) &&
2632 (!AfterLegalize||TLI.isLoadXLegal(ISD::SEXTLOAD, N0.getValueType()))){
2633 bool DoXform = true;
2634 SmallVector<SDNode*, 4> SetCCs;
2635 if (!N0.hasOneUse())
2636 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::SIGN_EXTEND, SetCCs, TLI);
2638 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2639 SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, LN0->getChain(),
2640 LN0->getBasePtr(), LN0->getSrcValue(),
2641 LN0->getSrcValueOffset(),
2644 LN0->getAlignment());
2645 CombineTo(N, ExtLoad);
2646 SDOperand Trunc = DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad);
2647 CombineTo(N0.Val, Trunc, ExtLoad.getValue(1));
2648 // Extend SetCC uses if necessary.
2649 for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
2650 SDNode *SetCC = SetCCs[i];
2651 SmallVector<SDOperand, 4> Ops;
2652 for (unsigned j = 0; j != 2; ++j) {
2653 SDOperand SOp = SetCC->getOperand(j);
2655 Ops.push_back(ExtLoad);
2657 Ops.push_back(DAG.getNode(ISD::SIGN_EXTEND, VT, SOp));
2659 Ops.push_back(SetCC->getOperand(2));
2660 CombineTo(SetCC, DAG.getNode(ISD::SETCC, SetCC->getValueType(0),
2661 &Ops[0], Ops.size()));
2663 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
2667 // fold (sext (sextload x)) -> (sext (truncate (sextload x)))
2668 // fold (sext ( extload x)) -> (sext (truncate (sextload x)))
2669 if ((ISD::isSEXTLoad(N0.Val) || ISD::isEXTLoad(N0.Val)) &&
2670 ISD::isUNINDEXEDLoad(N0.Val) && N0.hasOneUse()) {
2671 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2672 MVT::ValueType EVT = LN0->getLoadedVT();
2673 if (!AfterLegalize || TLI.isLoadXLegal(ISD::SEXTLOAD, EVT)) {
2674 SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, LN0->getChain(),
2675 LN0->getBasePtr(), LN0->getSrcValue(),
2676 LN0->getSrcValueOffset(), EVT,
2678 LN0->getAlignment());
2679 CombineTo(N, ExtLoad);
2680 CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
2681 ExtLoad.getValue(1));
2682 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
2686 // sext(setcc x,y,cc) -> select_cc x, y, -1, 0, cc
2687 if (N0.getOpcode() == ISD::SETCC) {
2689 SimplifySelectCC(N0.getOperand(0), N0.getOperand(1),
2690 DAG.getConstant(~0ULL, VT), DAG.getConstant(0, VT),
2691 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
2692 if (SCC.Val) return SCC;
2698 SDOperand DAGCombiner::visitZERO_EXTEND(SDNode *N) {
2699 SDOperand N0 = N->getOperand(0);
2700 MVT::ValueType VT = N->getValueType(0);
2702 // fold (zext c1) -> c1
2703 if (isa<ConstantSDNode>(N0))
2704 return DAG.getNode(ISD::ZERO_EXTEND, VT, N0);
2705 // fold (zext (zext x)) -> (zext x)
2706 // fold (zext (aext x)) -> (zext x)
2707 if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
2708 return DAG.getNode(ISD::ZERO_EXTEND, VT, N0.getOperand(0));
2710 // fold (zext (truncate (load x))) -> (zext (smaller load x))
2711 // fold (zext (truncate (srl (load x), c))) -> (zext (small load (x+c/n)))
2712 if (N0.getOpcode() == ISD::TRUNCATE) {
2713 SDOperand NarrowLoad = ReduceLoadWidth(N0.Val);
2714 if (NarrowLoad.Val) {
2715 if (NarrowLoad.Val != N0.Val)
2716 CombineTo(N0.Val, NarrowLoad);
2717 return DAG.getNode(ISD::ZERO_EXTEND, VT, NarrowLoad);
2721 // fold (zext (truncate x)) -> (and x, mask)
2722 if (N0.getOpcode() == ISD::TRUNCATE &&
2723 (!AfterLegalize || TLI.isOperationLegal(ISD::AND, VT))) {
2724 SDOperand Op = N0.getOperand(0);
2725 if (Op.getValueType() < VT) {
2726 Op = DAG.getNode(ISD::ANY_EXTEND, VT, Op);
2727 } else if (Op.getValueType() > VT) {
2728 Op = DAG.getNode(ISD::TRUNCATE, VT, Op);
2730 return DAG.getZeroExtendInReg(Op, N0.getValueType());
2733 // fold (zext (and (trunc x), cst)) -> (and x, cst).
2734 if (N0.getOpcode() == ISD::AND &&
2735 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
2736 N0.getOperand(1).getOpcode() == ISD::Constant) {
2737 SDOperand X = N0.getOperand(0).getOperand(0);
2738 if (X.getValueType() < VT) {
2739 X = DAG.getNode(ISD::ANY_EXTEND, VT, X);
2740 } else if (X.getValueType() > VT) {
2741 X = DAG.getNode(ISD::TRUNCATE, VT, X);
2743 uint64_t Mask = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
2744 return DAG.getNode(ISD::AND, VT, X, DAG.getConstant(Mask, VT));
2747 // fold (zext (load x)) -> (zext (truncate (zextload x)))
2748 if (ISD::isNON_EXTLoad(N0.Val) &&
2749 (!AfterLegalize||TLI.isLoadXLegal(ISD::ZEXTLOAD, N0.getValueType()))) {
2750 bool DoXform = true;
2751 SmallVector<SDNode*, 4> SetCCs;
2752 if (!N0.hasOneUse())
2753 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ZERO_EXTEND, SetCCs, TLI);
2755 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2756 SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(),
2757 LN0->getBasePtr(), LN0->getSrcValue(),
2758 LN0->getSrcValueOffset(),
2761 LN0->getAlignment());
2762 CombineTo(N, ExtLoad);
2763 SDOperand Trunc = DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad);
2764 CombineTo(N0.Val, Trunc, ExtLoad.getValue(1));
2765 // Extend SetCC uses if necessary.
2766 for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
2767 SDNode *SetCC = SetCCs[i];
2768 SmallVector<SDOperand, 4> Ops;
2769 for (unsigned j = 0; j != 2; ++j) {
2770 SDOperand SOp = SetCC->getOperand(j);
2772 Ops.push_back(ExtLoad);
2774 Ops.push_back(DAG.getNode(ISD::SIGN_EXTEND, VT, SOp));
2776 Ops.push_back(SetCC->getOperand(2));
2777 CombineTo(SetCC, DAG.getNode(ISD::SETCC, SetCC->getValueType(0),
2778 &Ops[0], Ops.size()));
2780 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
2784 // fold (zext (zextload x)) -> (zext (truncate (zextload x)))
2785 // fold (zext ( extload x)) -> (zext (truncate (zextload x)))
2786 if ((ISD::isZEXTLoad(N0.Val) || ISD::isEXTLoad(N0.Val)) &&
2787 ISD::isUNINDEXEDLoad(N0.Val) && N0.hasOneUse()) {
2788 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2789 MVT::ValueType EVT = LN0->getLoadedVT();
2790 SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(),
2791 LN0->getBasePtr(), LN0->getSrcValue(),
2792 LN0->getSrcValueOffset(), EVT,
2794 LN0->getAlignment());
2795 CombineTo(N, ExtLoad);
2796 CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
2797 ExtLoad.getValue(1));
2798 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
2801 // zext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
2802 if (N0.getOpcode() == ISD::SETCC) {
2804 SimplifySelectCC(N0.getOperand(0), N0.getOperand(1),
2805 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
2806 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
2807 if (SCC.Val) return SCC;
2813 SDOperand DAGCombiner::visitANY_EXTEND(SDNode *N) {
2814 SDOperand N0 = N->getOperand(0);
2815 MVT::ValueType VT = N->getValueType(0);
2817 // fold (aext c1) -> c1
2818 if (isa<ConstantSDNode>(N0))
2819 return DAG.getNode(ISD::ANY_EXTEND, VT, N0);
2820 // fold (aext (aext x)) -> (aext x)
2821 // fold (aext (zext x)) -> (zext x)
2822 // fold (aext (sext x)) -> (sext x)
2823 if (N0.getOpcode() == ISD::ANY_EXTEND ||
2824 N0.getOpcode() == ISD::ZERO_EXTEND ||
2825 N0.getOpcode() == ISD::SIGN_EXTEND)
2826 return DAG.getNode(N0.getOpcode(), VT, N0.getOperand(0));
2828 // fold (aext (truncate (load x))) -> (aext (smaller load x))
2829 // fold (aext (truncate (srl (load x), c))) -> (aext (small load (x+c/n)))
2830 if (N0.getOpcode() == ISD::TRUNCATE) {
2831 SDOperand NarrowLoad = ReduceLoadWidth(N0.Val);
2832 if (NarrowLoad.Val) {
2833 if (NarrowLoad.Val != N0.Val)
2834 CombineTo(N0.Val, NarrowLoad);
2835 return DAG.getNode(ISD::ANY_EXTEND, VT, NarrowLoad);
2839 // fold (aext (truncate x))
2840 if (N0.getOpcode() == ISD::TRUNCATE) {
2841 SDOperand TruncOp = N0.getOperand(0);
2842 if (TruncOp.getValueType() == VT)
2843 return TruncOp; // x iff x size == zext size.
2844 if (TruncOp.getValueType() > VT)
2845 return DAG.getNode(ISD::TRUNCATE, VT, TruncOp);
2846 return DAG.getNode(ISD::ANY_EXTEND, VT, TruncOp);
2849 // fold (aext (and (trunc x), cst)) -> (and x, cst).
2850 if (N0.getOpcode() == ISD::AND &&
2851 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
2852 N0.getOperand(1).getOpcode() == ISD::Constant) {
2853 SDOperand X = N0.getOperand(0).getOperand(0);
2854 if (X.getValueType() < VT) {
2855 X = DAG.getNode(ISD::ANY_EXTEND, VT, X);
2856 } else if (X.getValueType() > VT) {
2857 X = DAG.getNode(ISD::TRUNCATE, VT, X);
2859 uint64_t Mask = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
2860 return DAG.getNode(ISD::AND, VT, X, DAG.getConstant(Mask, VT));
2863 // fold (aext (load x)) -> (aext (truncate (extload x)))
2864 if (ISD::isNON_EXTLoad(N0.Val) && N0.hasOneUse() &&
2865 (!AfterLegalize||TLI.isLoadXLegal(ISD::EXTLOAD, N0.getValueType()))) {
2866 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2867 SDOperand ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, VT, LN0->getChain(),
2868 LN0->getBasePtr(), LN0->getSrcValue(),
2869 LN0->getSrcValueOffset(),
2872 LN0->getAlignment());
2873 CombineTo(N, ExtLoad);
2874 CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
2875 ExtLoad.getValue(1));
2876 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
2879 // fold (aext (zextload x)) -> (aext (truncate (zextload x)))
2880 // fold (aext (sextload x)) -> (aext (truncate (sextload x)))
2881 // fold (aext ( extload x)) -> (aext (truncate (extload x)))
2882 if (N0.getOpcode() == ISD::LOAD &&
2883 !ISD::isNON_EXTLoad(N0.Val) && ISD::isUNINDEXEDLoad(N0.Val) &&
2885 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2886 MVT::ValueType EVT = LN0->getLoadedVT();
2887 SDOperand ExtLoad = DAG.getExtLoad(LN0->getExtensionType(), VT,
2888 LN0->getChain(), LN0->getBasePtr(),
2890 LN0->getSrcValueOffset(), EVT,
2892 LN0->getAlignment());
2893 CombineTo(N, ExtLoad);
2894 CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
2895 ExtLoad.getValue(1));
2896 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
2899 // aext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
2900 if (N0.getOpcode() == ISD::SETCC) {
2902 SimplifySelectCC(N0.getOperand(0), N0.getOperand(1),
2903 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
2904 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
2912 /// GetDemandedBits - See if the specified operand can be simplified with the
2913 /// knowledge that only the bits specified by Mask are used. If so, return the
2914 /// simpler operand, otherwise return a null SDOperand.
2915 SDOperand DAGCombiner::GetDemandedBits(SDOperand V, uint64_t Mask) {
2916 switch (V.getOpcode()) {
2920 // If the LHS or RHS don't contribute bits to the or, drop them.
2921 if (DAG.MaskedValueIsZero(V.getOperand(0), Mask))
2922 return V.getOperand(1);
2923 if (DAG.MaskedValueIsZero(V.getOperand(1), Mask))
2924 return V.getOperand(0);
2927 // Only look at single-use SRLs.
2928 if (!V.Val->hasOneUse())
2930 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(V.getOperand(1))) {
2931 // See if we can recursively simplify the LHS.
2932 unsigned Amt = RHSC->getValue();
2933 Mask = (Mask << Amt) & MVT::getIntVTBitMask(V.getValueType());
2934 SDOperand SimplifyLHS = GetDemandedBits(V.getOperand(0), Mask);
2935 if (SimplifyLHS.Val) {
2936 return DAG.getNode(ISD::SRL, V.getValueType(),
2937 SimplifyLHS, V.getOperand(1));
2944 /// ReduceLoadWidth - If the result of a wider load is shifted to right of N
2945 /// bits and then truncated to a narrower type and where N is a multiple
2946 /// of number of bits of the narrower type, transform it to a narrower load
2947 /// from address + N / num of bits of new type. If the result is to be
2948 /// extended, also fold the extension to form a extending load.
2949 SDOperand DAGCombiner::ReduceLoadWidth(SDNode *N) {
2950 unsigned Opc = N->getOpcode();
2951 ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
2952 SDOperand N0 = N->getOperand(0);
2953 MVT::ValueType VT = N->getValueType(0);
2954 MVT::ValueType EVT = N->getValueType(0);
2956 // Special case: SIGN_EXTEND_INREG is basically truncating to EVT then
2958 if (Opc == ISD::SIGN_EXTEND_INREG) {
2959 ExtType = ISD::SEXTLOAD;
2960 EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
2961 if (AfterLegalize && !TLI.isLoadXLegal(ISD::SEXTLOAD, EVT))
2965 unsigned EVTBits = MVT::getSizeInBits(EVT);
2967 bool CombineSRL = false;
2968 if (N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
2969 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
2970 ShAmt = N01->getValue();
2971 // Is the shift amount a multiple of size of VT?
2972 if ((ShAmt & (EVTBits-1)) == 0) {
2973 N0 = N0.getOperand(0);
2974 if (MVT::getSizeInBits(N0.getValueType()) <= EVTBits)
2981 if (ISD::isNON_EXTLoad(N0.Val) && N0.hasOneUse() &&
2982 // Do not allow folding to i1 here. i1 is implicitly stored in memory in
2983 // zero extended form: by shrinking the load, we lose track of the fact
2984 // that it is already zero extended.
2985 // FIXME: This should be reevaluated.
2987 assert(MVT::getSizeInBits(N0.getValueType()) > EVTBits &&
2988 "Cannot truncate to larger type!");
2989 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2990 MVT::ValueType PtrType = N0.getOperand(1).getValueType();
2991 // For big endian targets, we need to adjust the offset to the pointer to
2992 // load the correct bytes.
2993 if (!TLI.isLittleEndian())
2994 ShAmt = MVT::getSizeInBits(N0.getValueType()) - ShAmt - EVTBits;
2995 uint64_t PtrOff = ShAmt / 8;
2996 unsigned NewAlign = MinAlign(LN0->getAlignment(), PtrOff);
2997 SDOperand NewPtr = DAG.getNode(ISD::ADD, PtrType, LN0->getBasePtr(),
2998 DAG.getConstant(PtrOff, PtrType));
2999 AddToWorkList(NewPtr.Val);
3000 SDOperand Load = (ExtType == ISD::NON_EXTLOAD)
3001 ? DAG.getLoad(VT, LN0->getChain(), NewPtr,
3002 LN0->getSrcValue(), LN0->getSrcValueOffset(),
3003 LN0->isVolatile(), NewAlign)
3004 : DAG.getExtLoad(ExtType, VT, LN0->getChain(), NewPtr,
3005 LN0->getSrcValue(), LN0->getSrcValueOffset(), EVT,
3006 LN0->isVolatile(), NewAlign);
3009 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));
3010 CombineTo(N->getOperand(0).Val, Load);
3012 CombineTo(N0.Val, Load, Load.getValue(1));
3014 if (Opc == ISD::SIGN_EXTEND_INREG)
3015 return DAG.getNode(Opc, VT, Load, N->getOperand(1));
3017 return DAG.getNode(Opc, VT, Load);
3019 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
3026 SDOperand DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
3027 SDOperand N0 = N->getOperand(0);
3028 SDOperand N1 = N->getOperand(1);
3029 MVT::ValueType VT = N->getValueType(0);
3030 MVT::ValueType EVT = cast<VTSDNode>(N1)->getVT();
3031 unsigned EVTBits = MVT::getSizeInBits(EVT);
3033 // fold (sext_in_reg c1) -> c1
3034 if (isa<ConstantSDNode>(N0) || N0.getOpcode() == ISD::UNDEF)
3035 return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, N0, N1);
3037 // If the input is already sign extended, just drop the extension.
3038 if (DAG.ComputeNumSignBits(N0) >= MVT::getSizeInBits(VT)-EVTBits+1)
3041 // fold (sext_in_reg (sext_in_reg x, VT2), VT1) -> (sext_in_reg x, minVT) pt2
3042 if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
3043 EVT < cast<VTSDNode>(N0.getOperand(1))->getVT()) {
3044 return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, N0.getOperand(0), N1);
3047 // fold (sext_in_reg x) -> (zext_in_reg x) if the sign bit is known zero.
3048 if (DAG.MaskedValueIsZero(N0, 1ULL << (EVTBits-1)))
3049 return DAG.getZeroExtendInReg(N0, EVT);
3051 // fold operands of sext_in_reg based on knowledge that the top bits are not
3053 if (SimplifyDemandedBits(SDOperand(N, 0)))
3054 return SDOperand(N, 0);
3056 // fold (sext_in_reg (load x)) -> (smaller sextload x)
3057 // fold (sext_in_reg (srl (load x), c)) -> (smaller sextload (x+c/evtbits))
3058 SDOperand NarrowLoad = ReduceLoadWidth(N);
3062 // fold (sext_in_reg (srl X, 24), i8) -> sra X, 24
3063 // fold (sext_in_reg (srl X, 23), i8) -> sra X, 23 iff possible.
3064 // We already fold "(sext_in_reg (srl X, 25), i8) -> srl X, 25" above.
3065 if (N0.getOpcode() == ISD::SRL) {
3066 if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
3067 if (ShAmt->getValue()+EVTBits <= MVT::getSizeInBits(VT)) {
3068 // We can turn this into an SRA iff the input to the SRL is already sign
3070 unsigned InSignBits = DAG.ComputeNumSignBits(N0.getOperand(0));
3071 if (MVT::getSizeInBits(VT)-(ShAmt->getValue()+EVTBits) < InSignBits)
3072 return DAG.getNode(ISD::SRA, VT, N0.getOperand(0), N0.getOperand(1));
3076 // fold (sext_inreg (extload x)) -> (sextload x)
3077 if (ISD::isEXTLoad(N0.Val) &&
3078 ISD::isUNINDEXEDLoad(N0.Val) &&
3079 EVT == cast<LoadSDNode>(N0)->getLoadedVT() &&
3080 (!AfterLegalize || TLI.isLoadXLegal(ISD::SEXTLOAD, EVT))) {
3081 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3082 SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, LN0->getChain(),
3083 LN0->getBasePtr(), LN0->getSrcValue(),
3084 LN0->getSrcValueOffset(), EVT,
3086 LN0->getAlignment());
3087 CombineTo(N, ExtLoad);
3088 CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
3089 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
3091 // fold (sext_inreg (zextload x)) -> (sextload x) iff load has one use
3092 if (ISD::isZEXTLoad(N0.Val) && ISD::isUNINDEXEDLoad(N0.Val) &&
3094 EVT == cast<LoadSDNode>(N0)->getLoadedVT() &&
3095 (!AfterLegalize || TLI.isLoadXLegal(ISD::SEXTLOAD, EVT))) {
3096 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3097 SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, LN0->getChain(),
3098 LN0->getBasePtr(), LN0->getSrcValue(),
3099 LN0->getSrcValueOffset(), EVT,
3101 LN0->getAlignment());
3102 CombineTo(N, ExtLoad);
3103 CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
3104 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
3109 SDOperand DAGCombiner::visitTRUNCATE(SDNode *N) {
3110 SDOperand N0 = N->getOperand(0);
3111 MVT::ValueType VT = N->getValueType(0);
3114 if (N0.getValueType() == N->getValueType(0))
3116 // fold (truncate c1) -> c1
3117 if (isa<ConstantSDNode>(N0))
3118 return DAG.getNode(ISD::TRUNCATE, VT, N0);
3119 // fold (truncate (truncate x)) -> (truncate x)
3120 if (N0.getOpcode() == ISD::TRUNCATE)
3121 return DAG.getNode(ISD::TRUNCATE, VT, N0.getOperand(0));
3122 // fold (truncate (ext x)) -> (ext x) or (truncate x) or x
3123 if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::SIGN_EXTEND||
3124 N0.getOpcode() == ISD::ANY_EXTEND) {
3125 if (N0.getOperand(0).getValueType() < VT)
3126 // if the source is smaller than the dest, we still need an extend
3127 return DAG.getNode(N0.getOpcode(), VT, N0.getOperand(0));
3128 else if (N0.getOperand(0).getValueType() > VT)
3129 // if the source is larger than the dest, than we just need the truncate
3130 return DAG.getNode(ISD::TRUNCATE, VT, N0.getOperand(0));
3132 // if the source and dest are the same type, we can drop both the extend
3134 return N0.getOperand(0);
3137 // See if we can simplify the input to this truncate through knowledge that
3138 // only the low bits are being used. For example "trunc (or (shl x, 8), y)"
3140 SDOperand Shorter = GetDemandedBits(N0, MVT::getIntVTBitMask(VT));
3142 return DAG.getNode(ISD::TRUNCATE, VT, Shorter);
3144 // fold (truncate (load x)) -> (smaller load x)
3145 // fold (truncate (srl (load x), c)) -> (smaller load (x+c/evtbits))
3146 return ReduceLoadWidth(N);
3149 SDOperand DAGCombiner::visitBIT_CONVERT(SDNode *N) {
3150 SDOperand N0 = N->getOperand(0);
3151 MVT::ValueType VT = N->getValueType(0);
3153 // If the input is a BUILD_VECTOR with all constant elements, fold this now.
3154 // Only do this before legalize, since afterward the target may be depending
3155 // on the bitconvert.
3156 // First check to see if this is all constant.
3157 if (!AfterLegalize &&
3158 N0.getOpcode() == ISD::BUILD_VECTOR && N0.Val->hasOneUse() &&
3159 MVT::isVector(VT)) {
3160 bool isSimple = true;
3161 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i)
3162 if (N0.getOperand(i).getOpcode() != ISD::UNDEF &&
3163 N0.getOperand(i).getOpcode() != ISD::Constant &&
3164 N0.getOperand(i).getOpcode() != ISD::ConstantFP) {
3169 MVT::ValueType DestEltVT = MVT::getVectorElementType(N->getValueType(0));
3170 assert(!MVT::isVector(DestEltVT) &&
3171 "Element type of vector ValueType must not be vector!");
3173 return ConstantFoldBIT_CONVERTofBUILD_VECTOR(N0.Val, DestEltVT);
3177 // If the input is a constant, let getNode() fold it.
3178 if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
3179 SDOperand Res = DAG.getNode(ISD::BIT_CONVERT, VT, N0);
3180 if (Res.Val != N) return Res;
3183 if (N0.getOpcode() == ISD::BIT_CONVERT) // conv(conv(x,t1),t2) -> conv(x,t2)
3184 return DAG.getNode(ISD::BIT_CONVERT, VT, N0.getOperand(0));
3186 // fold (conv (load x)) -> (load (conv*)x)
3187 // If the resultant load doesn't need a higher alignment than the original!
3188 if (ISD::isNormalLoad(N0.Val) && N0.hasOneUse() &&
3189 TLI.isOperationLegal(ISD::LOAD, VT)) {
3190 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3191 unsigned Align = TLI.getTargetMachine().getTargetData()->
3192 getABITypeAlignment(MVT::getTypeForValueType(VT));
3193 unsigned OrigAlign = LN0->getAlignment();
3194 if (Align <= OrigAlign) {
3195 SDOperand Load = DAG.getLoad(VT, LN0->getChain(), LN0->getBasePtr(),
3196 LN0->getSrcValue(), LN0->getSrcValueOffset(),
3197 LN0->isVolatile(), Align);
3199 CombineTo(N0.Val, DAG.getNode(ISD::BIT_CONVERT, N0.getValueType(), Load),
3208 /// ConstantFoldBIT_CONVERTofBUILD_VECTOR - We know that BV is a build_vector
3209 /// node with Constant, ConstantFP or Undef operands. DstEltVT indicates the
3210 /// destination element value type.
3211 SDOperand DAGCombiner::
3212 ConstantFoldBIT_CONVERTofBUILD_VECTOR(SDNode *BV, MVT::ValueType DstEltVT) {
3213 MVT::ValueType SrcEltVT = BV->getOperand(0).getValueType();
3215 // If this is already the right type, we're done.
3216 if (SrcEltVT == DstEltVT) return SDOperand(BV, 0);
3218 unsigned SrcBitSize = MVT::getSizeInBits(SrcEltVT);
3219 unsigned DstBitSize = MVT::getSizeInBits(DstEltVT);
3221 // If this is a conversion of N elements of one type to N elements of another
3222 // type, convert each element. This handles FP<->INT cases.
3223 if (SrcBitSize == DstBitSize) {
3224 SmallVector<SDOperand, 8> Ops;
3225 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
3226 Ops.push_back(DAG.getNode(ISD::BIT_CONVERT, DstEltVT, BV->getOperand(i)));
3227 AddToWorkList(Ops.back().Val);
3230 MVT::getVectorType(DstEltVT,
3231 MVT::getVectorNumElements(BV->getValueType(0)));
3232 return DAG.getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size());
3235 // Otherwise, we're growing or shrinking the elements. To avoid having to
3236 // handle annoying details of growing/shrinking FP values, we convert them to
3238 if (MVT::isFloatingPoint(SrcEltVT)) {
3239 // Convert the input float vector to a int vector where the elements are the
3241 assert((SrcEltVT == MVT::f32 || SrcEltVT == MVT::f64) && "Unknown FP VT!");
3242 MVT::ValueType IntVT = SrcEltVT == MVT::f32 ? MVT::i32 : MVT::i64;
3243 BV = ConstantFoldBIT_CONVERTofBUILD_VECTOR(BV, IntVT).Val;
3247 // Now we know the input is an integer vector. If the output is a FP type,
3248 // convert to integer first, then to FP of the right size.
3249 if (MVT::isFloatingPoint(DstEltVT)) {
3250 assert((DstEltVT == MVT::f32 || DstEltVT == MVT::f64) && "Unknown FP VT!");
3251 MVT::ValueType TmpVT = DstEltVT == MVT::f32 ? MVT::i32 : MVT::i64;
3252 SDNode *Tmp = ConstantFoldBIT_CONVERTofBUILD_VECTOR(BV, TmpVT).Val;
3254 // Next, convert to FP elements of the same size.
3255 return ConstantFoldBIT_CONVERTofBUILD_VECTOR(Tmp, DstEltVT);
3258 // Okay, we know the src/dst types are both integers of differing types.
3259 // Handling growing first.
3260 assert(MVT::isInteger(SrcEltVT) && MVT::isInteger(DstEltVT));
3261 if (SrcBitSize < DstBitSize) {
3262 unsigned NumInputsPerOutput = DstBitSize/SrcBitSize;
3264 SmallVector<SDOperand, 8> Ops;
3265 for (unsigned i = 0, e = BV->getNumOperands(); i != e;
3266 i += NumInputsPerOutput) {
3267 bool isLE = TLI.isLittleEndian();
3268 uint64_t NewBits = 0;
3269 bool EltIsUndef = true;
3270 for (unsigned j = 0; j != NumInputsPerOutput; ++j) {
3271 // Shift the previously computed bits over.
3272 NewBits <<= SrcBitSize;
3273 SDOperand Op = BV->getOperand(i+ (isLE ? (NumInputsPerOutput-j-1) : j));
3274 if (Op.getOpcode() == ISD::UNDEF) continue;
3277 NewBits |= cast<ConstantSDNode>(Op)->getValue();
3281 Ops.push_back(DAG.getNode(ISD::UNDEF, DstEltVT));
3283 Ops.push_back(DAG.getConstant(NewBits, DstEltVT));
3286 MVT::ValueType VT = MVT::getVectorType(DstEltVT,
3288 return DAG.getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size());
3291 // Finally, this must be the case where we are shrinking elements: each input
3292 // turns into multiple outputs.
3293 unsigned NumOutputsPerInput = SrcBitSize/DstBitSize;
3294 SmallVector<SDOperand, 8> Ops;
3295 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
3296 if (BV->getOperand(i).getOpcode() == ISD::UNDEF) {
3297 for (unsigned j = 0; j != NumOutputsPerInput; ++j)
3298 Ops.push_back(DAG.getNode(ISD::UNDEF, DstEltVT));
3301 uint64_t OpVal = cast<ConstantSDNode>(BV->getOperand(i))->getValue();
3303 for (unsigned j = 0; j != NumOutputsPerInput; ++j) {
3304 unsigned ThisVal = OpVal & ((1ULL << DstBitSize)-1);
3305 OpVal >>= DstBitSize;
3306 Ops.push_back(DAG.getConstant(ThisVal, DstEltVT));
3309 // For big endian targets, swap the order of the pieces of each element.
3310 if (!TLI.isLittleEndian())
3311 std::reverse(Ops.end()-NumOutputsPerInput, Ops.end());
3313 MVT::ValueType VT = MVT::getVectorType(DstEltVT, Ops.size());
3314 return DAG.getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size());
3319 SDOperand DAGCombiner::visitFADD(SDNode *N) {
3320 SDOperand N0 = N->getOperand(0);
3321 SDOperand N1 = N->getOperand(1);
3322 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3323 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
3324 MVT::ValueType VT = N->getValueType(0);
3327 if (MVT::isVector(VT)) {
3328 SDOperand FoldedVOp = SimplifyVBinOp(N);
3329 if (FoldedVOp.Val) return FoldedVOp;
3332 // fold (fadd c1, c2) -> c1+c2
3333 if (N0CFP && N1CFP && VT != MVT::ppcf128)
3334 return DAG.getNode(ISD::FADD, VT, N0, N1);
3335 // canonicalize constant to RHS
3336 if (N0CFP && !N1CFP)
3337 return DAG.getNode(ISD::FADD, VT, N1, N0);
3338 // fold (A + (-B)) -> A-B
3339 if (isNegatibleForFree(N1) == 2)
3340 return DAG.getNode(ISD::FSUB, VT, N0, GetNegatedExpression(N1, DAG));
3341 // fold ((-A) + B) -> B-A
3342 if (isNegatibleForFree(N0) == 2)
3343 return DAG.getNode(ISD::FSUB, VT, N1, GetNegatedExpression(N0, DAG));
3345 // If allowed, fold (fadd (fadd x, c1), c2) -> (fadd x, (fadd c1, c2))
3346 if (UnsafeFPMath && N1CFP && N0.getOpcode() == ISD::FADD &&
3347 N0.Val->hasOneUse() && isa<ConstantFPSDNode>(N0.getOperand(1)))
3348 return DAG.getNode(ISD::FADD, VT, N0.getOperand(0),
3349 DAG.getNode(ISD::FADD, VT, N0.getOperand(1), N1));
3354 SDOperand DAGCombiner::visitFSUB(SDNode *N) {
3355 SDOperand N0 = N->getOperand(0);
3356 SDOperand N1 = N->getOperand(1);
3357 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3358 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
3359 MVT::ValueType VT = N->getValueType(0);
3362 if (MVT::isVector(VT)) {
3363 SDOperand FoldedVOp = SimplifyVBinOp(N);
3364 if (FoldedVOp.Val) return FoldedVOp;
3367 // fold (fsub c1, c2) -> c1-c2
3368 if (N0CFP && N1CFP && VT != MVT::ppcf128)
3369 return DAG.getNode(ISD::FSUB, VT, N0, N1);
3371 if (UnsafeFPMath && N0CFP && N0CFP->getValueAPF().isZero()) {
3372 if (isNegatibleForFree(N1))
3373 return GetNegatedExpression(N1, DAG);
3374 return DAG.getNode(ISD::FNEG, VT, N1);
3376 // fold (A-(-B)) -> A+B
3377 if (isNegatibleForFree(N1))
3378 return DAG.getNode(ISD::FADD, VT, N0, GetNegatedExpression(N1, DAG));
3383 SDOperand DAGCombiner::visitFMUL(SDNode *N) {
3384 SDOperand N0 = N->getOperand(0);
3385 SDOperand N1 = N->getOperand(1);
3386 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3387 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
3388 MVT::ValueType VT = N->getValueType(0);
3391 if (MVT::isVector(VT)) {
3392 SDOperand FoldedVOp = SimplifyVBinOp(N);
3393 if (FoldedVOp.Val) return FoldedVOp;
3396 // fold (fmul c1, c2) -> c1*c2
3397 if (N0CFP && N1CFP && VT != MVT::ppcf128)
3398 return DAG.getNode(ISD::FMUL, VT, N0, N1);
3399 // canonicalize constant to RHS
3400 if (N0CFP && !N1CFP)
3401 return DAG.getNode(ISD::FMUL, VT, N1, N0);
3402 // fold (fmul X, 2.0) -> (fadd X, X)
3403 if (N1CFP && N1CFP->isExactlyValue(+2.0))
3404 return DAG.getNode(ISD::FADD, VT, N0, N0);
3405 // fold (fmul X, -1.0) -> (fneg X)
3406 if (N1CFP && N1CFP->isExactlyValue(-1.0))
3407 return DAG.getNode(ISD::FNEG, VT, N0);
3410 if (char LHSNeg = isNegatibleForFree(N0)) {
3411 if (char RHSNeg = isNegatibleForFree(N1)) {
3412 // Both can be negated for free, check to see if at least one is cheaper
3414 if (LHSNeg == 2 || RHSNeg == 2)
3415 return DAG.getNode(ISD::FMUL, VT, GetNegatedExpression(N0, DAG),
3416 GetNegatedExpression(N1, DAG));
3420 // If allowed, fold (fmul (fmul x, c1), c2) -> (fmul x, (fmul c1, c2))
3421 if (UnsafeFPMath && N1CFP && N0.getOpcode() == ISD::FMUL &&
3422 N0.Val->hasOneUse() && isa<ConstantFPSDNode>(N0.getOperand(1)))
3423 return DAG.getNode(ISD::FMUL, VT, N0.getOperand(0),
3424 DAG.getNode(ISD::FMUL, VT, N0.getOperand(1), N1));
3429 SDOperand DAGCombiner::visitFDIV(SDNode *N) {
3430 SDOperand N0 = N->getOperand(0);
3431 SDOperand N1 = N->getOperand(1);
3432 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3433 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
3434 MVT::ValueType VT = N->getValueType(0);
3437 if (MVT::isVector(VT)) {
3438 SDOperand FoldedVOp = SimplifyVBinOp(N);
3439 if (FoldedVOp.Val) return FoldedVOp;
3442 // fold (fdiv c1, c2) -> c1/c2
3443 if (N0CFP && N1CFP && VT != MVT::ppcf128)
3444 return DAG.getNode(ISD::FDIV, VT, N0, N1);
3448 if (char LHSNeg = isNegatibleForFree(N0)) {
3449 if (char RHSNeg = isNegatibleForFree(N1)) {
3450 // Both can be negated for free, check to see if at least one is cheaper
3452 if (LHSNeg == 2 || RHSNeg == 2)
3453 return DAG.getNode(ISD::FDIV, VT, GetNegatedExpression(N0, DAG),
3454 GetNegatedExpression(N1, DAG));
3461 SDOperand DAGCombiner::visitFREM(SDNode *N) {
3462 SDOperand N0 = N->getOperand(0);
3463 SDOperand N1 = N->getOperand(1);
3464 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3465 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
3466 MVT::ValueType VT = N->getValueType(0);
3468 // fold (frem c1, c2) -> fmod(c1,c2)
3469 if (N0CFP && N1CFP && VT != MVT::ppcf128)
3470 return DAG.getNode(ISD::FREM, VT, N0, N1);
3475 SDOperand DAGCombiner::visitFCOPYSIGN(SDNode *N) {
3476 SDOperand N0 = N->getOperand(0);
3477 SDOperand N1 = N->getOperand(1);
3478 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3479 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
3480 MVT::ValueType VT = N->getValueType(0);
3482 if (N0CFP && N1CFP && VT != MVT::ppcf128) // Constant fold
3483 return DAG.getNode(ISD::FCOPYSIGN, VT, N0, N1);
3486 const APFloat& V = N1CFP->getValueAPF();
3487 // copysign(x, c1) -> fabs(x) iff ispos(c1)
3488 // copysign(x, c1) -> fneg(fabs(x)) iff isneg(c1)
3489 if (!V.isNegative())
3490 return DAG.getNode(ISD::FABS, VT, N0);
3492 return DAG.getNode(ISD::FNEG, VT, DAG.getNode(ISD::FABS, VT, N0));
3495 // copysign(fabs(x), y) -> copysign(x, y)
3496 // copysign(fneg(x), y) -> copysign(x, y)
3497 // copysign(copysign(x,z), y) -> copysign(x, y)
3498 if (N0.getOpcode() == ISD::FABS || N0.getOpcode() == ISD::FNEG ||
3499 N0.getOpcode() == ISD::FCOPYSIGN)
3500 return DAG.getNode(ISD::FCOPYSIGN, VT, N0.getOperand(0), N1);
3502 // copysign(x, abs(y)) -> abs(x)
3503 if (N1.getOpcode() == ISD::FABS)
3504 return DAG.getNode(ISD::FABS, VT, N0);
3506 // copysign(x, copysign(y,z)) -> copysign(x, z)
3507 if (N1.getOpcode() == ISD::FCOPYSIGN)
3508 return DAG.getNode(ISD::FCOPYSIGN, VT, N0, N1.getOperand(1));
3510 // copysign(x, fp_extend(y)) -> copysign(x, y)
3511 // copysign(x, fp_round(y)) -> copysign(x, y)
3512 if (N1.getOpcode() == ISD::FP_EXTEND || N1.getOpcode() == ISD::FP_ROUND)
3513 return DAG.getNode(ISD::FCOPYSIGN, VT, N0, N1.getOperand(0));
3520 SDOperand DAGCombiner::visitSINT_TO_FP(SDNode *N) {
3521 SDOperand N0 = N->getOperand(0);
3522 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3523 MVT::ValueType VT = N->getValueType(0);
3525 // fold (sint_to_fp c1) -> c1fp
3526 if (N0C && N0.getValueType() != MVT::ppcf128)
3527 return DAG.getNode(ISD::SINT_TO_FP, VT, N0);
3531 SDOperand DAGCombiner::visitUINT_TO_FP(SDNode *N) {
3532 SDOperand N0 = N->getOperand(0);
3533 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3534 MVT::ValueType VT = N->getValueType(0);
3536 // fold (uint_to_fp c1) -> c1fp
3537 if (N0C && N0.getValueType() != MVT::ppcf128)
3538 return DAG.getNode(ISD::UINT_TO_FP, VT, N0);
3542 SDOperand DAGCombiner::visitFP_TO_SINT(SDNode *N) {
3543 SDOperand N0 = N->getOperand(0);
3544 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3545 MVT::ValueType VT = N->getValueType(0);
3547 // fold (fp_to_sint c1fp) -> c1
3549 return DAG.getNode(ISD::FP_TO_SINT, VT, N0);
3553 SDOperand DAGCombiner::visitFP_TO_UINT(SDNode *N) {
3554 SDOperand N0 = N->getOperand(0);
3555 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3556 MVT::ValueType VT = N->getValueType(0);
3558 // fold (fp_to_uint c1fp) -> c1
3559 if (N0CFP && VT != MVT::ppcf128)
3560 return DAG.getNode(ISD::FP_TO_UINT, VT, N0);
3564 SDOperand DAGCombiner::visitFP_ROUND(SDNode *N) {
3565 SDOperand N0 = N->getOperand(0);
3566 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3567 MVT::ValueType VT = N->getValueType(0);
3569 // fold (fp_round c1fp) -> c1fp
3570 if (N0CFP && N0.getValueType() != MVT::ppcf128)
3571 return DAG.getNode(ISD::FP_ROUND, VT, N0);
3573 // fold (fp_round (fp_extend x)) -> x
3574 if (N0.getOpcode() == ISD::FP_EXTEND && VT == N0.getOperand(0).getValueType())
3575 return N0.getOperand(0);
3577 // fold (fp_round (copysign X, Y)) -> (copysign (fp_round X), Y)
3578 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.Val->hasOneUse()) {
3579 SDOperand Tmp = DAG.getNode(ISD::FP_ROUND, VT, N0.getOperand(0));
3580 AddToWorkList(Tmp.Val);
3581 return DAG.getNode(ISD::FCOPYSIGN, VT, Tmp, N0.getOperand(1));
3587 SDOperand DAGCombiner::visitFP_ROUND_INREG(SDNode *N) {
3588 SDOperand N0 = N->getOperand(0);
3589 MVT::ValueType VT = N->getValueType(0);
3590 MVT::ValueType EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
3591 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3593 // fold (fp_round_inreg c1fp) -> c1fp
3595 SDOperand Round = DAG.getConstantFP(N0CFP->getValueAPF(), EVT);
3596 return DAG.getNode(ISD::FP_EXTEND, VT, Round);
3601 SDOperand DAGCombiner::visitFP_EXTEND(SDNode *N) {
3602 SDOperand N0 = N->getOperand(0);
3603 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3604 MVT::ValueType VT = N->getValueType(0);
3606 // fold (fp_extend c1fp) -> c1fp
3607 if (N0CFP && VT != MVT::ppcf128)
3608 return DAG.getNode(ISD::FP_EXTEND, VT, N0);
3610 // fold (fpext (load x)) -> (fpext (fpround (extload x)))
3611 if (ISD::isNON_EXTLoad(N0.Val) && N0.hasOneUse() &&
3612 (!AfterLegalize||TLI.isLoadXLegal(ISD::EXTLOAD, N0.getValueType()))) {
3613 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3614 SDOperand ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, VT, LN0->getChain(),
3615 LN0->getBasePtr(), LN0->getSrcValue(),
3616 LN0->getSrcValueOffset(),
3619 LN0->getAlignment());
3620 CombineTo(N, ExtLoad);
3621 CombineTo(N0.Val, DAG.getNode(ISD::FP_ROUND, N0.getValueType(), ExtLoad),
3622 ExtLoad.getValue(1));
3623 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
3630 SDOperand DAGCombiner::visitFNEG(SDNode *N) {
3631 SDOperand N0 = N->getOperand(0);
3633 if (isNegatibleForFree(N0))
3634 return GetNegatedExpression(N0, DAG);
3639 SDOperand DAGCombiner::visitFABS(SDNode *N) {
3640 SDOperand N0 = N->getOperand(0);
3641 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3642 MVT::ValueType VT = N->getValueType(0);
3644 // fold (fabs c1) -> fabs(c1)
3645 if (N0CFP && VT != MVT::ppcf128)
3646 return DAG.getNode(ISD::FABS, VT, N0);
3647 // fold (fabs (fabs x)) -> (fabs x)
3648 if (N0.getOpcode() == ISD::FABS)
3649 return N->getOperand(0);
3650 // fold (fabs (fneg x)) -> (fabs x)
3651 // fold (fabs (fcopysign x, y)) -> (fabs x)
3652 if (N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FCOPYSIGN)
3653 return DAG.getNode(ISD::FABS, VT, N0.getOperand(0));
3658 SDOperand DAGCombiner::visitBRCOND(SDNode *N) {
3659 SDOperand Chain = N->getOperand(0);
3660 SDOperand N1 = N->getOperand(1);
3661 SDOperand N2 = N->getOperand(2);
3662 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3664 // never taken branch, fold to chain
3665 if (N1C && N1C->isNullValue())
3667 // unconditional branch
3668 if (N1C && N1C->getValue() == 1)
3669 return DAG.getNode(ISD::BR, MVT::Other, Chain, N2);
3670 // fold a brcond with a setcc condition into a BR_CC node if BR_CC is legal
3672 if (N1.getOpcode() == ISD::SETCC &&
3673 TLI.isOperationLegal(ISD::BR_CC, MVT::Other)) {
3674 return DAG.getNode(ISD::BR_CC, MVT::Other, Chain, N1.getOperand(2),
3675 N1.getOperand(0), N1.getOperand(1), N2);
3680 // Operand List for BR_CC: Chain, CondCC, CondLHS, CondRHS, DestBB.
3682 SDOperand DAGCombiner::visitBR_CC(SDNode *N) {
3683 CondCodeSDNode *CC = cast<CondCodeSDNode>(N->getOperand(1));
3684 SDOperand CondLHS = N->getOperand(2), CondRHS = N->getOperand(3);
3686 // Use SimplifySetCC to simplify SETCC's.
3687 SDOperand Simp = SimplifySetCC(MVT::i1, CondLHS, CondRHS, CC->get(), false);
3688 if (Simp.Val) AddToWorkList(Simp.Val);
3690 ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(Simp.Val);
3692 // fold br_cc true, dest -> br dest (unconditional branch)
3693 if (SCCC && SCCC->getValue())
3694 return DAG.getNode(ISD::BR, MVT::Other, N->getOperand(0),
3696 // fold br_cc false, dest -> unconditional fall through
3697 if (SCCC && SCCC->isNullValue())
3698 return N->getOperand(0);
3700 // fold to a simpler setcc
3701 if (Simp.Val && Simp.getOpcode() == ISD::SETCC)
3702 return DAG.getNode(ISD::BR_CC, MVT::Other, N->getOperand(0),
3703 Simp.getOperand(2), Simp.getOperand(0),
3704 Simp.getOperand(1), N->getOperand(4));
3709 /// CombineToPreIndexedLoadStore - Try turning a load / store and a
3710 /// pre-indexed load / store when the base pointer is a add or subtract
3711 /// and it has other uses besides the load / store. After the
3712 /// transformation, the new indexed load / store has effectively folded
3713 /// the add / subtract in and all of its other uses are redirected to the
3714 /// new load / store.
3715 bool DAGCombiner::CombineToPreIndexedLoadStore(SDNode *N) {
3722 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
3723 if (LD->getAddressingMode() != ISD::UNINDEXED)
3725 VT = LD->getLoadedVT();
3726 if (!TLI.isIndexedLoadLegal(ISD::PRE_INC, VT) &&
3727 !TLI.isIndexedLoadLegal(ISD::PRE_DEC, VT))
3729 Ptr = LD->getBasePtr();
3730 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
3731 if (ST->getAddressingMode() != ISD::UNINDEXED)
3733 VT = ST->getStoredVT();
3734 if (!TLI.isIndexedStoreLegal(ISD::PRE_INC, VT) &&
3735 !TLI.isIndexedStoreLegal(ISD::PRE_DEC, VT))
3737 Ptr = ST->getBasePtr();
3742 // If the pointer is not an add/sub, or if it doesn't have multiple uses, bail
3743 // out. There is no reason to make this a preinc/predec.
3744 if ((Ptr.getOpcode() != ISD::ADD && Ptr.getOpcode() != ISD::SUB) ||
3745 Ptr.Val->hasOneUse())
3748 // Ask the target to do addressing mode selection.
3751 ISD::MemIndexedMode AM = ISD::UNINDEXED;
3752 if (!TLI.getPreIndexedAddressParts(N, BasePtr, Offset, AM, DAG))
3754 // Don't create a indexed load / store with zero offset.
3755 if (isa<ConstantSDNode>(Offset) &&
3756 cast<ConstantSDNode>(Offset)->getValue() == 0)
3759 // Try turning it into a pre-indexed load / store except when:
3760 // 1) The new base ptr is a frame index.
3761 // 2) If N is a store and the new base ptr is either the same as or is a
3762 // predecessor of the value being stored.
3763 // 3) Another use of old base ptr is a predecessor of N. If ptr is folded
3764 // that would create a cycle.
3765 // 4) All uses are load / store ops that use it as old base ptr.
3767 // Check #1. Preinc'ing a frame index would require copying the stack pointer
3768 // (plus the implicit offset) to a register to preinc anyway.
3769 if (isa<FrameIndexSDNode>(BasePtr))
3774 SDOperand Val = cast<StoreSDNode>(N)->getValue();
3775 if (Val == BasePtr || BasePtr.Val->isPredecessor(Val.Val))
3779 // Now check for #3 and #4.
3780 bool RealUse = false;
3781 for (SDNode::use_iterator I = Ptr.Val->use_begin(),
3782 E = Ptr.Val->use_end(); I != E; ++I) {
3786 if (Use->isPredecessor(N))
3789 if (!((Use->getOpcode() == ISD::LOAD &&
3790 cast<LoadSDNode>(Use)->getBasePtr() == Ptr) ||
3791 (Use->getOpcode() == ISD::STORE) &&
3792 cast<StoreSDNode>(Use)->getBasePtr() == Ptr))
3800 Result = DAG.getIndexedLoad(SDOperand(N,0), BasePtr, Offset, AM);
3802 Result = DAG.getIndexedStore(SDOperand(N,0), BasePtr, Offset, AM);
3805 DOUT << "\nReplacing.4 "; DEBUG(N->dump(&DAG));
3806 DOUT << "\nWith: "; DEBUG(Result.Val->dump(&DAG));
3808 std::vector<SDNode*> NowDead;
3810 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Result.getValue(0),
3812 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1), Result.getValue(2),
3815 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Result.getValue(1),
3819 // Nodes can end up on the worklist more than once. Make sure we do
3820 // not process a node that has been replaced.
3821 for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
3822 removeFromWorkList(NowDead[i]);
3823 // Finally, since the node is now dead, remove it from the graph.
3826 // Replace the uses of Ptr with uses of the updated base value.
3827 DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0),
3829 removeFromWorkList(Ptr.Val);
3830 for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
3831 removeFromWorkList(NowDead[i]);
3832 DAG.DeleteNode(Ptr.Val);
3837 /// CombineToPostIndexedLoadStore - Try combine a load / store with a
3838 /// add / sub of the base pointer node into a post-indexed load / store.
3839 /// The transformation folded the add / subtract into the new indexed
3840 /// load / store effectively and all of its uses are redirected to the
3841 /// new load / store.
3842 bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
3849 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
3850 if (LD->getAddressingMode() != ISD::UNINDEXED)
3852 VT = LD->getLoadedVT();
3853 if (!TLI.isIndexedLoadLegal(ISD::POST_INC, VT) &&
3854 !TLI.isIndexedLoadLegal(ISD::POST_DEC, VT))
3856 Ptr = LD->getBasePtr();
3857 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
3858 if (ST->getAddressingMode() != ISD::UNINDEXED)
3860 VT = ST->getStoredVT();
3861 if (!TLI.isIndexedStoreLegal(ISD::POST_INC, VT) &&
3862 !TLI.isIndexedStoreLegal(ISD::POST_DEC, VT))
3864 Ptr = ST->getBasePtr();
3869 if (Ptr.Val->hasOneUse())
3872 for (SDNode::use_iterator I = Ptr.Val->use_begin(),
3873 E = Ptr.Val->use_end(); I != E; ++I) {
3876 (Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB))
3881 ISD::MemIndexedMode AM = ISD::UNINDEXED;
3882 if (TLI.getPostIndexedAddressParts(N, Op, BasePtr, Offset, AM, DAG)) {
3884 std::swap(BasePtr, Offset);
3887 // Don't create a indexed load / store with zero offset.
3888 if (isa<ConstantSDNode>(Offset) &&
3889 cast<ConstantSDNode>(Offset)->getValue() == 0)
3892 // Try turning it into a post-indexed load / store except when
3893 // 1) All uses are load / store ops that use it as base ptr.
3894 // 2) Op must be independent of N, i.e. Op is neither a predecessor
3895 // nor a successor of N. Otherwise, if Op is folded that would
3899 bool TryNext = false;
3900 for (SDNode::use_iterator II = BasePtr.Val->use_begin(),
3901 EE = BasePtr.Val->use_end(); II != EE; ++II) {
3906 // If all the uses are load / store addresses, then don't do the
3908 if (Use->getOpcode() == ISD::ADD || Use->getOpcode() == ISD::SUB){
3909 bool RealUse = false;
3910 for (SDNode::use_iterator III = Use->use_begin(),
3911 EEE = Use->use_end(); III != EEE; ++III) {
3912 SDNode *UseUse = *III;
3913 if (!((UseUse->getOpcode() == ISD::LOAD &&
3914 cast<LoadSDNode>(UseUse)->getBasePtr().Val == Use) ||
3915 (UseUse->getOpcode() == ISD::STORE) &&
3916 cast<StoreSDNode>(UseUse)->getBasePtr().Val == Use))
3930 if (!Op->isPredecessor(N) && !N->isPredecessor(Op)) {
3931 SDOperand Result = isLoad
3932 ? DAG.getIndexedLoad(SDOperand(N,0), BasePtr, Offset, AM)
3933 : DAG.getIndexedStore(SDOperand(N,0), BasePtr, Offset, AM);
3936 DOUT << "\nReplacing.5 "; DEBUG(N->dump(&DAG));
3937 DOUT << "\nWith: "; DEBUG(Result.Val->dump(&DAG));
3939 std::vector<SDNode*> NowDead;
3941 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Result.getValue(0),
3943 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1), Result.getValue(2),
3946 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Result.getValue(1),
3950 // Nodes can end up on the worklist more than once. Make sure we do
3951 // not process a node that has been replaced.
3952 for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
3953 removeFromWorkList(NowDead[i]);
3954 // Finally, since the node is now dead, remove it from the graph.
3957 // Replace the uses of Use with uses of the updated base value.
3958 DAG.ReplaceAllUsesOfValueWith(SDOperand(Op, 0),
3959 Result.getValue(isLoad ? 1 : 0),
3961 removeFromWorkList(Op);
3962 for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
3963 removeFromWorkList(NowDead[i]);
3974 SDOperand DAGCombiner::visitLOAD(SDNode *N) {
3975 LoadSDNode *LD = cast<LoadSDNode>(N);
3976 SDOperand Chain = LD->getChain();
3977 SDOperand Ptr = LD->getBasePtr();
3979 // If load is not volatile and there are no uses of the loaded value (and
3980 // the updated indexed value in case of indexed loads), change uses of the
3981 // chain value into uses of the chain input (i.e. delete the dead load).
3982 if (!LD->isVolatile()) {
3983 if (N->getValueType(1) == MVT::Other) {
3985 if (N->hasNUsesOfValue(0, 0))
3986 return CombineTo(N, DAG.getNode(ISD::UNDEF, N->getValueType(0)), Chain);
3989 assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?");
3990 if (N->hasNUsesOfValue(0, 0) && N->hasNUsesOfValue(0, 1)) {
3991 SDOperand Undef0 = DAG.getNode(ISD::UNDEF, N->getValueType(0));
3992 SDOperand Undef1 = DAG.getNode(ISD::UNDEF, N->getValueType(1));
3993 SDOperand To[] = { Undef0, Undef1, Chain };
3994 return CombineTo(N, To, 3);
3999 // If this load is directly stored, replace the load value with the stored
4001 // TODO: Handle store large -> read small portion.
4002 // TODO: Handle TRUNCSTORE/LOADEXT
4003 if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
4004 if (ISD::isNON_TRUNCStore(Chain.Val)) {
4005 StoreSDNode *PrevST = cast<StoreSDNode>(Chain);
4006 if (PrevST->getBasePtr() == Ptr &&
4007 PrevST->getValue().getValueType() == N->getValueType(0))
4008 return CombineTo(N, Chain.getOperand(1), Chain);
4013 // Walk up chain skipping non-aliasing memory nodes.
4014 SDOperand BetterChain = FindBetterChain(N, Chain);
4016 // If there is a better chain.
4017 if (Chain != BetterChain) {
4020 // Replace the chain to void dependency.
4021 if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
4022 ReplLoad = DAG.getLoad(N->getValueType(0), BetterChain, Ptr,
4023 LD->getSrcValue(), LD->getSrcValueOffset(),
4024 LD->isVolatile(), LD->getAlignment());
4026 ReplLoad = DAG.getExtLoad(LD->getExtensionType(),
4027 LD->getValueType(0),
4028 BetterChain, Ptr, LD->getSrcValue(),
4029 LD->getSrcValueOffset(),
4032 LD->getAlignment());
4035 // Create token factor to keep old chain connected.
4036 SDOperand Token = DAG.getNode(ISD::TokenFactor, MVT::Other,
4037 Chain, ReplLoad.getValue(1));
4039 // Replace uses with load result and token factor. Don't add users
4041 return CombineTo(N, ReplLoad.getValue(0), Token, false);
4045 // Try transforming N to an indexed load.
4046 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
4047 return SDOperand(N, 0);
4052 SDOperand DAGCombiner::visitSTORE(SDNode *N) {
4053 StoreSDNode *ST = cast<StoreSDNode>(N);
4054 SDOperand Chain = ST->getChain();
4055 SDOperand Value = ST->getValue();
4056 SDOperand Ptr = ST->getBasePtr();
4058 // If this is a store of a bit convert, store the input value if the
4059 // resultant store does not need a higher alignment than the original.
4060 if (Value.getOpcode() == ISD::BIT_CONVERT && !ST->isTruncatingStore() &&
4061 ST->getAddressingMode() == ISD::UNINDEXED) {
4062 unsigned Align = ST->getAlignment();
4063 MVT::ValueType SVT = Value.getOperand(0).getValueType();
4064 unsigned OrigAlign = TLI.getTargetMachine().getTargetData()->
4065 getABITypeAlignment(MVT::getTypeForValueType(SVT));
4066 if (Align <= OrigAlign && TLI.isOperationLegal(ISD::STORE, SVT))
4067 return DAG.getStore(Chain, Value.getOperand(0), Ptr, ST->getSrcValue(),
4068 ST->getSrcValueOffset(), ST->isVolatile(), Align);
4071 // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
4072 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Value)) {
4073 if (Value.getOpcode() != ISD::TargetConstantFP) {
4075 switch (CFP->getValueType(0)) {
4076 default: assert(0 && "Unknown FP type");
4077 case MVT::f80: // We don't do this for these yet.
4082 if (!AfterLegalize || TLI.isTypeLegal(MVT::i32)) {
4083 Tmp = DAG.getConstant((uint32_t)CFP->getValueAPF().
4084 convertToAPInt().getZExtValue(), MVT::i32);
4085 return DAG.getStore(Chain, Tmp, Ptr, ST->getSrcValue(),
4086 ST->getSrcValueOffset(), ST->isVolatile(),
4087 ST->getAlignment());
4091 if (!AfterLegalize || TLI.isTypeLegal(MVT::i64)) {
4092 Tmp = DAG.getConstant(CFP->getValueAPF().convertToAPInt().
4093 getZExtValue(), MVT::i64);
4094 return DAG.getStore(Chain, Tmp, Ptr, ST->getSrcValue(),
4095 ST->getSrcValueOffset(), ST->isVolatile(),
4096 ST->getAlignment());
4097 } else if (TLI.isTypeLegal(MVT::i32)) {
4098 // Many FP stores are not made apparent until after legalize, e.g. for
4099 // argument passing. Since this is so common, custom legalize the
4100 // 64-bit integer store into two 32-bit stores.
4101 uint64_t Val = CFP->getValueAPF().convertToAPInt().getZExtValue();
4102 SDOperand Lo = DAG.getConstant(Val & 0xFFFFFFFF, MVT::i32);
4103 SDOperand Hi = DAG.getConstant(Val >> 32, MVT::i32);
4104 if (!TLI.isLittleEndian()) std::swap(Lo, Hi);
4106 int SVOffset = ST->getSrcValueOffset();
4107 unsigned Alignment = ST->getAlignment();
4108 bool isVolatile = ST->isVolatile();
4110 SDOperand St0 = DAG.getStore(Chain, Lo, Ptr, ST->getSrcValue(),
4111 ST->getSrcValueOffset(),
4112 isVolatile, ST->getAlignment());
4113 Ptr = DAG.getNode(ISD::ADD, Ptr.getValueType(), Ptr,
4114 DAG.getConstant(4, Ptr.getValueType()));
4116 Alignment = MinAlign(Alignment, 4U);
4117 SDOperand St1 = DAG.getStore(Chain, Hi, Ptr, ST->getSrcValue(),
4118 SVOffset, isVolatile, Alignment);
4119 return DAG.getNode(ISD::TokenFactor, MVT::Other, St0, St1);
4127 // Walk up chain skipping non-aliasing memory nodes.
4128 SDOperand BetterChain = FindBetterChain(N, Chain);
4130 // If there is a better chain.
4131 if (Chain != BetterChain) {
4132 // Replace the chain to avoid dependency.
4133 SDOperand ReplStore;
4134 if (ST->isTruncatingStore()) {
4135 ReplStore = DAG.getTruncStore(BetterChain, Value, Ptr,
4136 ST->getSrcValue(), ST->getSrcValueOffset(), ST->getStoredVT(),
4137 ST->isVolatile(), ST->getAlignment());
4139 ReplStore = DAG.getStore(BetterChain, Value, Ptr,
4140 ST->getSrcValue(), ST->getSrcValueOffset(),
4141 ST->isVolatile(), ST->getAlignment());
4144 // Create token to keep both nodes around.
4146 DAG.getNode(ISD::TokenFactor, MVT::Other, Chain, ReplStore);
4148 // Don't add users to work list.
4149 return CombineTo(N, Token, false);
4153 // Try transforming N to an indexed store.
4154 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
4155 return SDOperand(N, 0);
4157 // FIXME: is there such a think as a truncating indexed store?
4158 if (ST->isTruncatingStore() && ST->getAddressingMode() == ISD::UNINDEXED &&
4159 MVT::isInteger(Value.getValueType())) {
4160 // See if we can simplify the input to this truncstore with knowledge that
4161 // only the low bits are being used. For example:
4162 // "truncstore (or (shl x, 8), y), i8" -> "truncstore y, i8"
4164 GetDemandedBits(Value, MVT::getIntVTBitMask(ST->getStoredVT()));
4165 AddToWorkList(Value.Val);
4167 return DAG.getTruncStore(Chain, Shorter, Ptr, ST->getSrcValue(),
4168 ST->getSrcValueOffset(), ST->getStoredVT(),
4169 ST->isVolatile(), ST->getAlignment());
4171 // Otherwise, see if we can simplify the operation with
4172 // SimplifyDemandedBits, which only works if the value has a single use.
4173 if (SimplifyDemandedBits(Value, MVT::getIntVTBitMask(ST->getStoredVT())))
4174 return SDOperand(N, 0);
4180 SDOperand DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) {
4181 SDOperand InVec = N->getOperand(0);
4182 SDOperand InVal = N->getOperand(1);
4183 SDOperand EltNo = N->getOperand(2);
4185 // If the invec is a BUILD_VECTOR and if EltNo is a constant, build a new
4186 // vector with the inserted element.
4187 if (InVec.getOpcode() == ISD::BUILD_VECTOR && isa<ConstantSDNode>(EltNo)) {
4188 unsigned Elt = cast<ConstantSDNode>(EltNo)->getValue();
4189 SmallVector<SDOperand, 8> Ops(InVec.Val->op_begin(), InVec.Val->op_end());
4190 if (Elt < Ops.size())
4192 return DAG.getNode(ISD::BUILD_VECTOR, InVec.getValueType(),
4193 &Ops[0], Ops.size());
4199 SDOperand DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) {
4200 SDOperand InVec = N->getOperand(0);
4201 SDOperand EltNo = N->getOperand(1);
4203 // (vextract (v4f32 s2v (f32 load $addr)), 0) -> (f32 load $addr)
4204 // (vextract (v4i32 bc (v4f32 s2v (f32 load $addr))), 0) -> (i32 load $addr)
4205 if (isa<ConstantSDNode>(EltNo)) {
4206 unsigned Elt = cast<ConstantSDNode>(EltNo)->getValue();
4207 bool NewLoad = false;
4209 MVT::ValueType VT = InVec.getValueType();
4210 MVT::ValueType EVT = MVT::getVectorElementType(VT);
4211 MVT::ValueType LVT = EVT;
4212 unsigned NumElts = MVT::getVectorNumElements(VT);
4213 if (InVec.getOpcode() == ISD::BIT_CONVERT) {
4214 MVT::ValueType BCVT = InVec.getOperand(0).getValueType();
4215 if (!MVT::isVector(BCVT) ||
4216 NumElts != MVT::getVectorNumElements(BCVT))
4218 InVec = InVec.getOperand(0);
4219 EVT = MVT::getVectorElementType(BCVT);
4222 if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR &&
4223 InVec.getOperand(0).getValueType() == EVT &&
4224 ISD::isNormalLoad(InVec.getOperand(0).Val) &&
4225 InVec.getOperand(0).hasOneUse()) {
4226 LoadSDNode *LN0 = cast<LoadSDNode>(InVec.getOperand(0));
4227 unsigned Align = LN0->getAlignment();
4229 // Check the resultant load doesn't need a higher alignment than the
4231 unsigned NewAlign = TLI.getTargetMachine().getTargetData()->
4232 getABITypeAlignment(MVT::getTypeForValueType(LVT));
4233 if (!TLI.isOperationLegal(ISD::LOAD, LVT) || NewAlign > Align)
4238 return DAG.getLoad(LVT, LN0->getChain(), LN0->getBasePtr(),
4239 LN0->getSrcValue(), LN0->getSrcValueOffset(),
4240 LN0->isVolatile(), Align);
4248 SDOperand DAGCombiner::visitBUILD_VECTOR(SDNode *N) {
4249 unsigned NumInScalars = N->getNumOperands();
4250 MVT::ValueType VT = N->getValueType(0);
4251 unsigned NumElts = MVT::getVectorNumElements(VT);
4252 MVT::ValueType EltType = MVT::getVectorElementType(VT);
4254 // Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT
4255 // operations. If so, and if the EXTRACT_VECTOR_ELT vector inputs come from
4256 // at most two distinct vectors, turn this into a shuffle node.
4257 SDOperand VecIn1, VecIn2;
4258 for (unsigned i = 0; i != NumInScalars; ++i) {
4259 // Ignore undef inputs.
4260 if (N->getOperand(i).getOpcode() == ISD::UNDEF) continue;
4262 // If this input is something other than a EXTRACT_VECTOR_ELT with a
4263 // constant index, bail out.
4264 if (N->getOperand(i).getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
4265 !isa<ConstantSDNode>(N->getOperand(i).getOperand(1))) {
4266 VecIn1 = VecIn2 = SDOperand(0, 0);
4270 // If the input vector type disagrees with the result of the build_vector,
4271 // we can't make a shuffle.
4272 SDOperand ExtractedFromVec = N->getOperand(i).getOperand(0);
4273 if (ExtractedFromVec.getValueType() != VT) {
4274 VecIn1 = VecIn2 = SDOperand(0, 0);
4278 // Otherwise, remember this. We allow up to two distinct input vectors.
4279 if (ExtractedFromVec == VecIn1 || ExtractedFromVec == VecIn2)
4282 if (VecIn1.Val == 0) {
4283 VecIn1 = ExtractedFromVec;
4284 } else if (VecIn2.Val == 0) {
4285 VecIn2 = ExtractedFromVec;
4288 VecIn1 = VecIn2 = SDOperand(0, 0);
4293 // If everything is good, we can make a shuffle operation.
4295 SmallVector<SDOperand, 8> BuildVecIndices;
4296 for (unsigned i = 0; i != NumInScalars; ++i) {
4297 if (N->getOperand(i).getOpcode() == ISD::UNDEF) {
4298 BuildVecIndices.push_back(DAG.getNode(ISD::UNDEF, TLI.getPointerTy()));
4302 SDOperand Extract = N->getOperand(i);
4304 // If extracting from the first vector, just use the index directly.
4305 if (Extract.getOperand(0) == VecIn1) {
4306 BuildVecIndices.push_back(Extract.getOperand(1));
4310 // Otherwise, use InIdx + VecSize
4311 unsigned Idx = cast<ConstantSDNode>(Extract.getOperand(1))->getValue();
4312 BuildVecIndices.push_back(DAG.getConstant(Idx+NumInScalars,
4313 TLI.getPointerTy()));
4316 // Add count and size info.
4317 MVT::ValueType BuildVecVT =
4318 MVT::getVectorType(TLI.getPointerTy(), NumElts);
4320 // Return the new VECTOR_SHUFFLE node.
4326 // Use an undef build_vector as input for the second operand.
4327 std::vector<SDOperand> UnOps(NumInScalars,
4328 DAG.getNode(ISD::UNDEF,
4330 Ops[1] = DAG.getNode(ISD::BUILD_VECTOR, VT,
4331 &UnOps[0], UnOps.size());
4332 AddToWorkList(Ops[1].Val);
4334 Ops[2] = DAG.getNode(ISD::BUILD_VECTOR, BuildVecVT,
4335 &BuildVecIndices[0], BuildVecIndices.size());
4336 return DAG.getNode(ISD::VECTOR_SHUFFLE, VT, Ops, 3);
4342 SDOperand DAGCombiner::visitCONCAT_VECTORS(SDNode *N) {
4343 // TODO: Check to see if this is a CONCAT_VECTORS of a bunch of
4344 // EXTRACT_SUBVECTOR operations. If so, and if the EXTRACT_SUBVECTOR vector
4345 // inputs come from at most two distinct vectors, turn this into a shuffle
4348 // If we only have one input vector, we don't need to do any concatenation.
4349 if (N->getNumOperands() == 1) {
4350 return N->getOperand(0);
4356 SDOperand DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
4357 SDOperand ShufMask = N->getOperand(2);
4358 unsigned NumElts = ShufMask.getNumOperands();
4360 // If the shuffle mask is an identity operation on the LHS, return the LHS.
4361 bool isIdentity = true;
4362 for (unsigned i = 0; i != NumElts; ++i) {
4363 if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF &&
4364 cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() != i) {
4369 if (isIdentity) return N->getOperand(0);
4371 // If the shuffle mask is an identity operation on the RHS, return the RHS.
4373 for (unsigned i = 0; i != NumElts; ++i) {
4374 if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF &&
4375 cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() != i+NumElts) {
4380 if (isIdentity) return N->getOperand(1);
4382 // Check if the shuffle is a unary shuffle, i.e. one of the vectors is not
4384 bool isUnary = true;
4385 bool isSplat = true;
4387 unsigned BaseIdx = 0;
4388 for (unsigned i = 0; i != NumElts; ++i)
4389 if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF) {
4390 unsigned Idx = cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue();
4391 int V = (Idx < NumElts) ? 0 : 1;
4405 SDOperand N0 = N->getOperand(0);
4406 SDOperand N1 = N->getOperand(1);
4407 // Normalize unary shuffle so the RHS is undef.
4408 if (isUnary && VecNum == 1)
4411 // If it is a splat, check if the argument vector is a build_vector with
4412 // all scalar elements the same.
4416 // If this is a bit convert that changes the element type of the vector but
4417 // not the number of vector elements, look through it. Be careful not to
4418 // look though conversions that change things like v4f32 to v2f64.
4419 if (V->getOpcode() == ISD::BIT_CONVERT) {
4420 SDOperand ConvInput = V->getOperand(0);
4421 if (MVT::getVectorNumElements(ConvInput.getValueType()) == NumElts)
4425 if (V->getOpcode() == ISD::BUILD_VECTOR) {
4426 unsigned NumElems = V->getNumOperands();
4427 if (NumElems > BaseIdx) {
4429 bool AllSame = true;
4430 for (unsigned i = 0; i != NumElems; ++i) {
4431 if (V->getOperand(i).getOpcode() != ISD::UNDEF) {
4432 Base = V->getOperand(i);
4436 // Splat of <u, u, u, u>, return <u, u, u, u>
4439 for (unsigned i = 0; i != NumElems; ++i) {
4440 if (V->getOperand(i) != Base) {
4445 // Splat of <x, x, x, x>, return <x, x, x, x>
4452 // If it is a unary or the LHS and the RHS are the same node, turn the RHS
4454 if (isUnary || N0 == N1) {
4455 // Check the SHUFFLE mask, mapping any inputs from the 2nd operand into the
4457 SmallVector<SDOperand, 8> MappedOps;
4458 for (unsigned i = 0; i != NumElts; ++i) {
4459 if (ShufMask.getOperand(i).getOpcode() == ISD::UNDEF ||
4460 cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() < NumElts) {
4461 MappedOps.push_back(ShufMask.getOperand(i));
4464 cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() - NumElts;
4465 MappedOps.push_back(DAG.getConstant(NewIdx, MVT::i32));
4468 ShufMask = DAG.getNode(ISD::BUILD_VECTOR, ShufMask.getValueType(),
4469 &MappedOps[0], MappedOps.size());
4470 AddToWorkList(ShufMask.Val);
4471 return DAG.getNode(ISD::VECTOR_SHUFFLE, N->getValueType(0),
4473 DAG.getNode(ISD::UNDEF, N->getValueType(0)),
4480 /// XformToShuffleWithZero - Returns a vector_shuffle if it able to transform
4481 /// an AND to a vector_shuffle with the destination vector and a zero vector.
4482 /// e.g. AND V, <0xffffffff, 0, 0xffffffff, 0>. ==>
4483 /// vector_shuffle V, Zero, <0, 4, 2, 4>
4484 SDOperand DAGCombiner::XformToShuffleWithZero(SDNode *N) {
4485 SDOperand LHS = N->getOperand(0);
4486 SDOperand RHS = N->getOperand(1);
4487 if (N->getOpcode() == ISD::AND) {
4488 if (RHS.getOpcode() == ISD::BIT_CONVERT)
4489 RHS = RHS.getOperand(0);
4490 if (RHS.getOpcode() == ISD::BUILD_VECTOR) {
4491 std::vector<SDOperand> IdxOps;
4492 unsigned NumOps = RHS.getNumOperands();
4493 unsigned NumElts = NumOps;
4494 MVT::ValueType EVT = MVT::getVectorElementType(RHS.getValueType());
4495 for (unsigned i = 0; i != NumElts; ++i) {
4496 SDOperand Elt = RHS.getOperand(i);
4497 if (!isa<ConstantSDNode>(Elt))
4499 else if (cast<ConstantSDNode>(Elt)->isAllOnesValue())
4500 IdxOps.push_back(DAG.getConstant(i, EVT));
4501 else if (cast<ConstantSDNode>(Elt)->isNullValue())
4502 IdxOps.push_back(DAG.getConstant(NumElts, EVT));
4507 // Let's see if the target supports this vector_shuffle.
4508 if (!TLI.isVectorClearMaskLegal(IdxOps, EVT, DAG))
4511 // Return the new VECTOR_SHUFFLE node.
4512 MVT::ValueType VT = MVT::getVectorType(EVT, NumElts);
4513 std::vector<SDOperand> Ops;
4514 LHS = DAG.getNode(ISD::BIT_CONVERT, VT, LHS);
4516 AddToWorkList(LHS.Val);
4517 std::vector<SDOperand> ZeroOps(NumElts, DAG.getConstant(0, EVT));
4518 Ops.push_back(DAG.getNode(ISD::BUILD_VECTOR, VT,
4519 &ZeroOps[0], ZeroOps.size()));
4520 Ops.push_back(DAG.getNode(ISD::BUILD_VECTOR, VT,
4521 &IdxOps[0], IdxOps.size()));
4522 SDOperand Result = DAG.getNode(ISD::VECTOR_SHUFFLE, VT,
4523 &Ops[0], Ops.size());
4524 if (VT != LHS.getValueType()) {
4525 Result = DAG.getNode(ISD::BIT_CONVERT, LHS.getValueType(), Result);
4533 /// SimplifyVBinOp - Visit a binary vector operation, like ADD.
4534 SDOperand DAGCombiner::SimplifyVBinOp(SDNode *N) {
4535 // After legalize, the target may be depending on adds and other
4536 // binary ops to provide legal ways to construct constants or other
4537 // things. Simplifying them may result in a loss of legality.
4538 if (AfterLegalize) return SDOperand();
4540 MVT::ValueType VT = N->getValueType(0);
4541 assert(MVT::isVector(VT) && "SimplifyVBinOp only works on vectors!");
4543 MVT::ValueType EltType = MVT::getVectorElementType(VT);
4544 SDOperand LHS = N->getOperand(0);
4545 SDOperand RHS = N->getOperand(1);
4546 SDOperand Shuffle = XformToShuffleWithZero(N);
4547 if (Shuffle.Val) return Shuffle;
4549 // If the LHS and RHS are BUILD_VECTOR nodes, see if we can constant fold
4551 if (LHS.getOpcode() == ISD::BUILD_VECTOR &&
4552 RHS.getOpcode() == ISD::BUILD_VECTOR) {
4553 SmallVector<SDOperand, 8> Ops;
4554 for (unsigned i = 0, e = LHS.getNumOperands(); i != e; ++i) {
4555 SDOperand LHSOp = LHS.getOperand(i);
4556 SDOperand RHSOp = RHS.getOperand(i);
4557 // If these two elements can't be folded, bail out.
4558 if ((LHSOp.getOpcode() != ISD::UNDEF &&
4559 LHSOp.getOpcode() != ISD::Constant &&
4560 LHSOp.getOpcode() != ISD::ConstantFP) ||
4561 (RHSOp.getOpcode() != ISD::UNDEF &&
4562 RHSOp.getOpcode() != ISD::Constant &&
4563 RHSOp.getOpcode() != ISD::ConstantFP))
4565 // Can't fold divide by zero.
4566 if (N->getOpcode() == ISD::SDIV || N->getOpcode() == ISD::UDIV ||
4567 N->getOpcode() == ISD::FDIV) {
4568 if ((RHSOp.getOpcode() == ISD::Constant &&
4569 cast<ConstantSDNode>(RHSOp.Val)->isNullValue()) ||
4570 (RHSOp.getOpcode() == ISD::ConstantFP &&
4571 cast<ConstantFPSDNode>(RHSOp.Val)->getValueAPF().isZero()))
4574 Ops.push_back(DAG.getNode(N->getOpcode(), EltType, LHSOp, RHSOp));
4575 AddToWorkList(Ops.back().Val);
4576 assert((Ops.back().getOpcode() == ISD::UNDEF ||
4577 Ops.back().getOpcode() == ISD::Constant ||
4578 Ops.back().getOpcode() == ISD::ConstantFP) &&
4579 "Scalar binop didn't fold!");
4582 if (Ops.size() == LHS.getNumOperands()) {
4583 MVT::ValueType VT = LHS.getValueType();
4584 return DAG.getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size());
4591 SDOperand DAGCombiner::SimplifySelect(SDOperand N0, SDOperand N1, SDOperand N2){
4592 assert(N0.getOpcode() ==ISD::SETCC && "First argument must be a SetCC node!");
4594 SDOperand SCC = SimplifySelectCC(N0.getOperand(0), N0.getOperand(1), N1, N2,
4595 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4596 // If we got a simplified select_cc node back from SimplifySelectCC, then
4597 // break it down into a new SETCC node, and a new SELECT node, and then return
4598 // the SELECT node, since we were called with a SELECT node.
4600 // Check to see if we got a select_cc back (to turn into setcc/select).
4601 // Otherwise, just return whatever node we got back, like fabs.
4602 if (SCC.getOpcode() == ISD::SELECT_CC) {
4603 SDOperand SETCC = DAG.getNode(ISD::SETCC, N0.getValueType(),
4604 SCC.getOperand(0), SCC.getOperand(1),
4606 AddToWorkList(SETCC.Val);
4607 return DAG.getNode(ISD::SELECT, SCC.getValueType(), SCC.getOperand(2),
4608 SCC.getOperand(3), SETCC);
4615 /// SimplifySelectOps - Given a SELECT or a SELECT_CC node, where LHS and RHS
4616 /// are the two values being selected between, see if we can simplify the
4617 /// select. Callers of this should assume that TheSelect is deleted if this
4618 /// returns true. As such, they should return the appropriate thing (e.g. the
4619 /// node) back to the top-level of the DAG combiner loop to avoid it being
4622 bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDOperand LHS,
4625 // If this is a select from two identical things, try to pull the operation
4626 // through the select.
4627 if (LHS.getOpcode() == RHS.getOpcode() && LHS.hasOneUse() && RHS.hasOneUse()){
4628 // If this is a load and the token chain is identical, replace the select
4629 // of two loads with a load through a select of the address to load from.
4630 // This triggers in things like "select bool X, 10.0, 123.0" after the FP
4631 // constants have been dropped into the constant pool.
4632 if (LHS.getOpcode() == ISD::LOAD &&
4633 // Token chains must be identical.
4634 LHS.getOperand(0) == RHS.getOperand(0)) {
4635 LoadSDNode *LLD = cast<LoadSDNode>(LHS);
4636 LoadSDNode *RLD = cast<LoadSDNode>(RHS);
4638 // If this is an EXTLOAD, the VT's must match.
4639 if (LLD->getLoadedVT() == RLD->getLoadedVT()) {
4640 // FIXME: this conflates two src values, discarding one. This is not
4641 // the right thing to do, but nothing uses srcvalues now. When they do,
4642 // turn SrcValue into a list of locations.
4644 if (TheSelect->getOpcode() == ISD::SELECT) {
4645 // Check that the condition doesn't reach either load. If so, folding
4646 // this will induce a cycle into the DAG.
4647 if (!LLD->isPredecessor(TheSelect->getOperand(0).Val) &&
4648 !RLD->isPredecessor(TheSelect->getOperand(0).Val)) {
4649 Addr = DAG.getNode(ISD::SELECT, LLD->getBasePtr().getValueType(),
4650 TheSelect->getOperand(0), LLD->getBasePtr(),
4654 // Check that the condition doesn't reach either load. If so, folding
4655 // this will induce a cycle into the DAG.
4656 if (!LLD->isPredecessor(TheSelect->getOperand(0).Val) &&
4657 !RLD->isPredecessor(TheSelect->getOperand(0).Val) &&
4658 !LLD->isPredecessor(TheSelect->getOperand(1).Val) &&
4659 !RLD->isPredecessor(TheSelect->getOperand(1).Val)) {
4660 Addr = DAG.getNode(ISD::SELECT_CC, LLD->getBasePtr().getValueType(),
4661 TheSelect->getOperand(0),
4662 TheSelect->getOperand(1),
4663 LLD->getBasePtr(), RLD->getBasePtr(),
4664 TheSelect->getOperand(4));
4670 if (LLD->getExtensionType() == ISD::NON_EXTLOAD)
4671 Load = DAG.getLoad(TheSelect->getValueType(0), LLD->getChain(),
4672 Addr,LLD->getSrcValue(),
4673 LLD->getSrcValueOffset(),
4675 LLD->getAlignment());
4677 Load = DAG.getExtLoad(LLD->getExtensionType(),
4678 TheSelect->getValueType(0),
4679 LLD->getChain(), Addr, LLD->getSrcValue(),
4680 LLD->getSrcValueOffset(),
4683 LLD->getAlignment());
4685 // Users of the select now use the result of the load.
4686 CombineTo(TheSelect, Load);
4688 // Users of the old loads now use the new load's chain. We know the
4689 // old-load value is dead now.
4690 CombineTo(LHS.Val, Load.getValue(0), Load.getValue(1));
4691 CombineTo(RHS.Val, Load.getValue(0), Load.getValue(1));
4701 SDOperand DAGCombiner::SimplifySelectCC(SDOperand N0, SDOperand N1,
4702 SDOperand N2, SDOperand N3,
4703 ISD::CondCode CC, bool NotExtCompare) {
4705 MVT::ValueType VT = N2.getValueType();
4706 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
4707 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val);
4708 ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N3.Val);
4710 // Determine if the condition we're dealing with is constant
4711 SDOperand SCC = SimplifySetCC(TLI.getSetCCResultTy(), N0, N1, CC, false);
4712 if (SCC.Val) AddToWorkList(SCC.Val);
4713 ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.Val);
4715 // fold select_cc true, x, y -> x
4716 if (SCCC && SCCC->getValue())
4718 // fold select_cc false, x, y -> y
4719 if (SCCC && SCCC->getValue() == 0)
4722 // Check to see if we can simplify the select into an fabs node
4723 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1)) {
4724 // Allow either -0.0 or 0.0
4725 if (CFP->getValueAPF().isZero()) {
4726 // select (setg[te] X, +/-0.0), X, fneg(X) -> fabs
4727 if ((CC == ISD::SETGE || CC == ISD::SETGT) &&
4728 N0 == N2 && N3.getOpcode() == ISD::FNEG &&
4729 N2 == N3.getOperand(0))
4730 return DAG.getNode(ISD::FABS, VT, N0);
4732 // select (setl[te] X, +/-0.0), fneg(X), X -> fabs
4733 if ((CC == ISD::SETLT || CC == ISD::SETLE) &&
4734 N0 == N3 && N2.getOpcode() == ISD::FNEG &&
4735 N2.getOperand(0) == N3)
4736 return DAG.getNode(ISD::FABS, VT, N3);
4740 // Check to see if we can perform the "gzip trick", transforming
4741 // select_cc setlt X, 0, A, 0 -> and (sra X, size(X)-1), A
4742 if (N1C && N3C && N3C->isNullValue() && CC == ISD::SETLT &&
4743 MVT::isInteger(N0.getValueType()) &&
4744 MVT::isInteger(N2.getValueType()) &&
4745 (N1C->isNullValue() || // (a < 0) ? b : 0
4746 (N1C->getValue() == 1 && N0 == N2))) { // (a < 1) ? a : 0
4747 MVT::ValueType XType = N0.getValueType();
4748 MVT::ValueType AType = N2.getValueType();
4749 if (XType >= AType) {
4750 // and (sra X, size(X)-1, A) -> "and (srl X, C2), A" iff A is a
4751 // single-bit constant.
4752 if (N2C && ((N2C->getValue() & (N2C->getValue()-1)) == 0)) {
4753 unsigned ShCtV = Log2_64(N2C->getValue());
4754 ShCtV = MVT::getSizeInBits(XType)-ShCtV-1;
4755 SDOperand ShCt = DAG.getConstant(ShCtV, TLI.getShiftAmountTy());
4756 SDOperand Shift = DAG.getNode(ISD::SRL, XType, N0, ShCt);
4757 AddToWorkList(Shift.Val);
4758 if (XType > AType) {
4759 Shift = DAG.getNode(ISD::TRUNCATE, AType, Shift);
4760 AddToWorkList(Shift.Val);
4762 return DAG.getNode(ISD::AND, AType, Shift, N2);
4764 SDOperand Shift = DAG.getNode(ISD::SRA, XType, N0,
4765 DAG.getConstant(MVT::getSizeInBits(XType)-1,
4766 TLI.getShiftAmountTy()));
4767 AddToWorkList(Shift.Val);
4768 if (XType > AType) {
4769 Shift = DAG.getNode(ISD::TRUNCATE, AType, Shift);
4770 AddToWorkList(Shift.Val);
4772 return DAG.getNode(ISD::AND, AType, Shift, N2);
4776 // fold select C, 16, 0 -> shl C, 4
4777 if (N2C && N3C && N3C->isNullValue() && isPowerOf2_64(N2C->getValue()) &&
4778 TLI.getSetCCResultContents() == TargetLowering::ZeroOrOneSetCCResult) {
4780 // If the caller doesn't want us to simplify this into a zext of a compare,
4782 if (NotExtCompare && N2C->getValue() == 1)
4785 // Get a SetCC of the condition
4786 // FIXME: Should probably make sure that setcc is legal if we ever have a
4787 // target where it isn't.
4788 SDOperand Temp, SCC;
4789 // cast from setcc result type to select result type
4790 if (AfterLegalize) {
4791 SCC = DAG.getSetCC(TLI.getSetCCResultTy(), N0, N1, CC);
4792 if (N2.getValueType() < SCC.getValueType())
4793 Temp = DAG.getZeroExtendInReg(SCC, N2.getValueType());
4795 Temp = DAG.getNode(ISD::ZERO_EXTEND, N2.getValueType(), SCC);
4797 SCC = DAG.getSetCC(MVT::i1, N0, N1, CC);
4798 Temp = DAG.getNode(ISD::ZERO_EXTEND, N2.getValueType(), SCC);
4800 AddToWorkList(SCC.Val);
4801 AddToWorkList(Temp.Val);
4803 if (N2C->getValue() == 1)
4805 // shl setcc result by log2 n2c
4806 return DAG.getNode(ISD::SHL, N2.getValueType(), Temp,
4807 DAG.getConstant(Log2_64(N2C->getValue()),
4808 TLI.getShiftAmountTy()));
4811 // Check to see if this is the equivalent of setcc
4812 // FIXME: Turn all of these into setcc if setcc if setcc is legal
4813 // otherwise, go ahead with the folds.
4814 if (0 && N3C && N3C->isNullValue() && N2C && (N2C->getValue() == 1ULL)) {
4815 MVT::ValueType XType = N0.getValueType();
4816 if (TLI.isOperationLegal(ISD::SETCC, TLI.getSetCCResultTy())) {
4817 SDOperand Res = DAG.getSetCC(TLI.getSetCCResultTy(), N0, N1, CC);
4818 if (Res.getValueType() != VT)
4819 Res = DAG.getNode(ISD::ZERO_EXTEND, VT, Res);
4823 // seteq X, 0 -> srl (ctlz X, log2(size(X)))
4824 if (N1C && N1C->isNullValue() && CC == ISD::SETEQ &&
4825 TLI.isOperationLegal(ISD::CTLZ, XType)) {
4826 SDOperand Ctlz = DAG.getNode(ISD::CTLZ, XType, N0);
4827 return DAG.getNode(ISD::SRL, XType, Ctlz,
4828 DAG.getConstant(Log2_32(MVT::getSizeInBits(XType)),
4829 TLI.getShiftAmountTy()));
4831 // setgt X, 0 -> srl (and (-X, ~X), size(X)-1)
4832 if (N1C && N1C->isNullValue() && CC == ISD::SETGT) {
4833 SDOperand NegN0 = DAG.getNode(ISD::SUB, XType, DAG.getConstant(0, XType),
4835 SDOperand NotN0 = DAG.getNode(ISD::XOR, XType, N0,
4836 DAG.getConstant(~0ULL, XType));
4837 return DAG.getNode(ISD::SRL, XType,
4838 DAG.getNode(ISD::AND, XType, NegN0, NotN0),
4839 DAG.getConstant(MVT::getSizeInBits(XType)-1,
4840 TLI.getShiftAmountTy()));
4842 // setgt X, -1 -> xor (srl (X, size(X)-1), 1)
4843 if (N1C && N1C->isAllOnesValue() && CC == ISD::SETGT) {
4844 SDOperand Sign = DAG.getNode(ISD::SRL, XType, N0,
4845 DAG.getConstant(MVT::getSizeInBits(XType)-1,
4846 TLI.getShiftAmountTy()));
4847 return DAG.getNode(ISD::XOR, XType, Sign, DAG.getConstant(1, XType));
4851 // Check to see if this is an integer abs. select_cc setl[te] X, 0, -X, X ->
4852 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
4853 if (N1C && N1C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE) &&
4854 N0 == N3 && N2.getOpcode() == ISD::SUB && N0 == N2.getOperand(1) &&
4855 N2.getOperand(0) == N1 && MVT::isInteger(N0.getValueType())) {
4856 MVT::ValueType XType = N0.getValueType();
4857 SDOperand Shift = DAG.getNode(ISD::SRA, XType, N0,
4858 DAG.getConstant(MVT::getSizeInBits(XType)-1,
4859 TLI.getShiftAmountTy()));
4860 SDOperand Add = DAG.getNode(ISD::ADD, XType, N0, Shift);
4861 AddToWorkList(Shift.Val);
4862 AddToWorkList(Add.Val);
4863 return DAG.getNode(ISD::XOR, XType, Add, Shift);
4865 // Check to see if this is an integer abs. select_cc setgt X, -1, X, -X ->
4866 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
4867 if (N1C && N1C->isAllOnesValue() && CC == ISD::SETGT &&
4868 N0 == N2 && N3.getOpcode() == ISD::SUB && N0 == N3.getOperand(1)) {
4869 if (ConstantSDNode *SubC = dyn_cast<ConstantSDNode>(N3.getOperand(0))) {
4870 MVT::ValueType XType = N0.getValueType();
4871 if (SubC->isNullValue() && MVT::isInteger(XType)) {
4872 SDOperand Shift = DAG.getNode(ISD::SRA, XType, N0,
4873 DAG.getConstant(MVT::getSizeInBits(XType)-1,
4874 TLI.getShiftAmountTy()));
4875 SDOperand Add = DAG.getNode(ISD::ADD, XType, N0, Shift);
4876 AddToWorkList(Shift.Val);
4877 AddToWorkList(Add.Val);
4878 return DAG.getNode(ISD::XOR, XType, Add, Shift);
4886 /// SimplifySetCC - This is a stub for TargetLowering::SimplifySetCC.
4887 SDOperand DAGCombiner::SimplifySetCC(MVT::ValueType VT, SDOperand N0,
4888 SDOperand N1, ISD::CondCode Cond,
4889 bool foldBooleans) {
4890 TargetLowering::DAGCombinerInfo
4891 DagCombineInfo(DAG, !AfterLegalize, false, this);
4892 return TLI.SimplifySetCC(VT, N0, N1, Cond, foldBooleans, DagCombineInfo);
4895 /// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
4896 /// return a DAG expression to select that will generate the same value by
4897 /// multiplying by a magic number. See:
4898 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
4899 SDOperand DAGCombiner::BuildSDIV(SDNode *N) {
4900 std::vector<SDNode*> Built;
4901 SDOperand S = TLI.BuildSDIV(N, DAG, &Built);
4903 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
4909 /// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant,
4910 /// return a DAG expression to select that will generate the same value by
4911 /// multiplying by a magic number. See:
4912 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
4913 SDOperand DAGCombiner::BuildUDIV(SDNode *N) {
4914 std::vector<SDNode*> Built;
4915 SDOperand S = TLI.BuildUDIV(N, DAG, &Built);
4917 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
4923 /// FindBaseOffset - Return true if base is known not to alias with anything
4924 /// but itself. Provides base object and offset as results.
4925 static bool FindBaseOffset(SDOperand Ptr, SDOperand &Base, int64_t &Offset) {
4926 // Assume it is a primitive operation.
4927 Base = Ptr; Offset = 0;
4929 // If it's an adding a simple constant then integrate the offset.
4930 if (Base.getOpcode() == ISD::ADD) {
4931 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Base.getOperand(1))) {
4932 Base = Base.getOperand(0);
4933 Offset += C->getValue();
4937 // If it's any of the following then it can't alias with anything but itself.
4938 return isa<FrameIndexSDNode>(Base) ||
4939 isa<ConstantPoolSDNode>(Base) ||
4940 isa<GlobalAddressSDNode>(Base);
4943 /// isAlias - Return true if there is any possibility that the two addresses
4945 bool DAGCombiner::isAlias(SDOperand Ptr1, int64_t Size1,
4946 const Value *SrcValue1, int SrcValueOffset1,
4947 SDOperand Ptr2, int64_t Size2,
4948 const Value *SrcValue2, int SrcValueOffset2)
4950 // If they are the same then they must be aliases.
4951 if (Ptr1 == Ptr2) return true;
4953 // Gather base node and offset information.
4954 SDOperand Base1, Base2;
4955 int64_t Offset1, Offset2;
4956 bool KnownBase1 = FindBaseOffset(Ptr1, Base1, Offset1);
4957 bool KnownBase2 = FindBaseOffset(Ptr2, Base2, Offset2);
4959 // If they have a same base address then...
4960 if (Base1 == Base2) {
4961 // Check to see if the addresses overlap.
4962 return!((Offset1 + Size1) <= Offset2 || (Offset2 + Size2) <= Offset1);
4965 // If we know both bases then they can't alias.
4966 if (KnownBase1 && KnownBase2) return false;
4968 if (CombinerGlobalAA) {
4969 // Use alias analysis information.
4970 int64_t MinOffset = std::min(SrcValueOffset1, SrcValueOffset2);
4971 int64_t Overlap1 = Size1 + SrcValueOffset1 - MinOffset;
4972 int64_t Overlap2 = Size2 + SrcValueOffset2 - MinOffset;
4973 AliasAnalysis::AliasResult AAResult =
4974 AA.alias(SrcValue1, Overlap1, SrcValue2, Overlap2);
4975 if (AAResult == AliasAnalysis::NoAlias)
4979 // Otherwise we have to assume they alias.
4983 /// FindAliasInfo - Extracts the relevant alias information from the memory
4984 /// node. Returns true if the operand was a load.
4985 bool DAGCombiner::FindAliasInfo(SDNode *N,
4986 SDOperand &Ptr, int64_t &Size,
4987 const Value *&SrcValue, int &SrcValueOffset) {
4988 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
4989 Ptr = LD->getBasePtr();
4990 Size = MVT::getSizeInBits(LD->getLoadedVT()) >> 3;
4991 SrcValue = LD->getSrcValue();
4992 SrcValueOffset = LD->getSrcValueOffset();
4994 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
4995 Ptr = ST->getBasePtr();
4996 Size = MVT::getSizeInBits(ST->getStoredVT()) >> 3;
4997 SrcValue = ST->getSrcValue();
4998 SrcValueOffset = ST->getSrcValueOffset();
5000 assert(0 && "FindAliasInfo expected a memory operand");
5006 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
5007 /// looking for aliasing nodes and adding them to the Aliases vector.
5008 void DAGCombiner::GatherAllAliases(SDNode *N, SDOperand OriginalChain,
5009 SmallVector<SDOperand, 8> &Aliases) {
5010 SmallVector<SDOperand, 8> Chains; // List of chains to visit.
5011 std::set<SDNode *> Visited; // Visited node set.
5013 // Get alias information for node.
5016 const Value *SrcValue;
5018 bool IsLoad = FindAliasInfo(N, Ptr, Size, SrcValue, SrcValueOffset);
5021 Chains.push_back(OriginalChain);
5023 // Look at each chain and determine if it is an alias. If so, add it to the
5024 // aliases list. If not, then continue up the chain looking for the next
5026 while (!Chains.empty()) {
5027 SDOperand Chain = Chains.back();
5030 // Don't bother if we've been before.
5031 if (Visited.find(Chain.Val) != Visited.end()) continue;
5032 Visited.insert(Chain.Val);
5034 switch (Chain.getOpcode()) {
5035 case ISD::EntryToken:
5036 // Entry token is ideal chain operand, but handled in FindBetterChain.
5041 // Get alias information for Chain.
5044 const Value *OpSrcValue;
5045 int OpSrcValueOffset;
5046 bool IsOpLoad = FindAliasInfo(Chain.Val, OpPtr, OpSize,
5047 OpSrcValue, OpSrcValueOffset);
5049 // If chain is alias then stop here.
5050 if (!(IsLoad && IsOpLoad) &&
5051 isAlias(Ptr, Size, SrcValue, SrcValueOffset,
5052 OpPtr, OpSize, OpSrcValue, OpSrcValueOffset)) {
5053 Aliases.push_back(Chain);
5055 // Look further up the chain.
5056 Chains.push_back(Chain.getOperand(0));
5057 // Clean up old chain.
5058 AddToWorkList(Chain.Val);
5063 case ISD::TokenFactor:
5064 // We have to check each of the operands of the token factor, so we queue
5065 // then up. Adding the operands to the queue (stack) in reverse order
5066 // maintains the original order and increases the likelihood that getNode
5067 // will find a matching token factor (CSE.)
5068 for (unsigned n = Chain.getNumOperands(); n;)
5069 Chains.push_back(Chain.getOperand(--n));
5070 // Eliminate the token factor if we can.
5071 AddToWorkList(Chain.Val);
5075 // For all other instructions we will just have to take what we can get.
5076 Aliases.push_back(Chain);
5082 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes, looking
5083 /// for a better chain (aliasing node.)
5084 SDOperand DAGCombiner::FindBetterChain(SDNode *N, SDOperand OldChain) {
5085 SmallVector<SDOperand, 8> Aliases; // Ops for replacing token factor.
5087 // Accumulate all the aliases to this node.
5088 GatherAllAliases(N, OldChain, Aliases);
5090 if (Aliases.size() == 0) {
5091 // If no operands then chain to entry token.
5092 return DAG.getEntryNode();
5093 } else if (Aliases.size() == 1) {
5094 // If a single operand then chain to it. We don't need to revisit it.
5098 // Construct a custom tailored token factor.
5099 SDOperand NewChain = DAG.getNode(ISD::TokenFactor, MVT::Other,
5100 &Aliases[0], Aliases.size());
5102 // Make sure the old chain gets cleaned up.
5103 if (NewChain != OldChain) AddToWorkList(OldChain.Val);
5108 // SelectionDAG::Combine - This is the entry point for the file.
5110 void SelectionDAG::Combine(bool RunningAfterLegalize, AliasAnalysis &AA) {
5111 if (!RunningAfterLegalize && ViewDAGCombine1)
5113 if (RunningAfterLegalize && ViewDAGCombine2)
5115 /// run - This is the main entry point to this class.
5117 DAGCombiner(*this, AA).Run(RunningAfterLegalize);