1 //===-- DAGCombiner.cpp - Implement a DAG node combiner -------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This pass combines dag nodes to form fewer, simpler DAG nodes. It can be run
11 // both before and after the DAG is legalized.
13 // This pass is not a substitute for the LLVM IR instcombine pass. This pass is
14 // primarily intended to handle simplification opportunities that are implicit
15 // in the LLVM IR and exposed by the various codegen lowering phases.
17 //===----------------------------------------------------------------------===//
19 #define DEBUG_TYPE "dagcombine"
20 #include "llvm/CodeGen/SelectionDAG.h"
21 #include "llvm/DerivedTypes.h"
22 #include "llvm/LLVMContext.h"
23 #include "llvm/CodeGen/MachineFunction.h"
24 #include "llvm/CodeGen/MachineFrameInfo.h"
25 #include "llvm/Analysis/AliasAnalysis.h"
26 #include "llvm/DataLayout.h"
27 #include "llvm/Target/TargetLowering.h"
28 #include "llvm/Target/TargetMachine.h"
29 #include "llvm/Target/TargetOptions.h"
30 #include "llvm/ADT/SmallPtrSet.h"
31 #include "llvm/ADT/Statistic.h"
32 #include "llvm/Support/CommandLine.h"
33 #include "llvm/Support/Debug.h"
34 #include "llvm/Support/ErrorHandling.h"
35 #include "llvm/Support/MathExtras.h"
36 #include "llvm/Support/raw_ostream.h"
40 STATISTIC(NodesCombined , "Number of dag nodes combined");
41 STATISTIC(PreIndexedNodes , "Number of pre-indexed nodes created");
42 STATISTIC(PostIndexedNodes, "Number of post-indexed nodes created");
43 STATISTIC(OpsNarrowed , "Number of load/op/store narrowed");
44 STATISTIC(LdStFP2Int , "Number of fp load/store pairs transformed to int");
48 CombinerAA("combiner-alias-analysis", cl::Hidden,
49 cl::desc("Turn on alias analysis during testing"));
52 CombinerGlobalAA("combiner-global-alias-analysis", cl::Hidden,
53 cl::desc("Include global information in alias analysis"));
55 //------------------------------ DAGCombiner ---------------------------------//
59 const TargetLowering &TLI;
61 CodeGenOpt::Level OptLevel;
65 // Worklist of all of the nodes that need to be simplified.
67 // This has the semantics that when adding to the worklist,
68 // the item added must be next to be processed. It should
69 // also only appear once. The naive approach to this takes
72 // To reduce the insert/remove time to logarithmic, we use
73 // a set and a vector to maintain our worklist.
75 // The set contains the items on the worklist, but does not
76 // maintain the order they should be visited.
78 // The vector maintains the order nodes should be visited, but may
79 // contain duplicate or removed nodes. When choosing a node to
80 // visit, we pop off the order stack until we find an item that is
81 // also in the contents set. All operations are O(log N).
82 SmallPtrSet<SDNode*, 64> WorkListContents;
83 SmallVector<SDNode*, 64> WorkListOrder;
85 // AA - Used for DAG load/store alias analysis.
88 /// AddUsersToWorkList - When an instruction is simplified, add all users of
89 /// the instruction to the work lists because they might get more simplified
92 void AddUsersToWorkList(SDNode *N) {
93 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
98 /// visit - call the node-specific routine that knows how to fold each
99 /// particular type of node.
100 SDValue visit(SDNode *N);
103 /// AddToWorkList - Add to the work list making sure its instance is at the
104 /// back (next to be processed.)
105 void AddToWorkList(SDNode *N) {
106 WorkListContents.insert(N);
107 WorkListOrder.push_back(N);
110 /// removeFromWorkList - remove all instances of N from the worklist.
112 void removeFromWorkList(SDNode *N) {
113 WorkListContents.erase(N);
116 SDValue CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
119 SDValue CombineTo(SDNode *N, SDValue Res, bool AddTo = true) {
120 return CombineTo(N, &Res, 1, AddTo);
123 SDValue CombineTo(SDNode *N, SDValue Res0, SDValue Res1,
125 SDValue To[] = { Res0, Res1 };
126 return CombineTo(N, To, 2, AddTo);
129 void CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO);
133 /// SimplifyDemandedBits - Check the specified integer node value to see if
134 /// it can be simplified or if things it uses can be simplified by bit
135 /// propagation. If so, return true.
136 bool SimplifyDemandedBits(SDValue Op) {
137 unsigned BitWidth = Op.getValueType().getScalarType().getSizeInBits();
138 APInt Demanded = APInt::getAllOnesValue(BitWidth);
139 return SimplifyDemandedBits(Op, Demanded);
142 bool SimplifyDemandedBits(SDValue Op, const APInt &Demanded);
144 bool CombineToPreIndexedLoadStore(SDNode *N);
145 bool CombineToPostIndexedLoadStore(SDNode *N);
147 void ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad);
148 SDValue PromoteOperand(SDValue Op, EVT PVT, bool &Replace);
149 SDValue SExtPromoteOperand(SDValue Op, EVT PVT);
150 SDValue ZExtPromoteOperand(SDValue Op, EVT PVT);
151 SDValue PromoteIntBinOp(SDValue Op);
152 SDValue PromoteIntShiftOp(SDValue Op);
153 SDValue PromoteExtend(SDValue Op);
154 bool PromoteLoad(SDValue Op);
156 void ExtendSetCCUses(SmallVector<SDNode*, 4> SetCCs,
157 SDValue Trunc, SDValue ExtLoad, DebugLoc DL,
158 ISD::NodeType ExtType);
160 /// combine - call the node-specific routine that knows how to fold each
161 /// particular type of node. If that doesn't do anything, try the
162 /// target-specific DAG combines.
163 SDValue combine(SDNode *N);
165 // Visitation implementation - Implement dag node combining for different
166 // node types. The semantics are as follows:
168 // SDValue.getNode() == 0 - No change was made
169 // SDValue.getNode() == N - N was replaced, is dead and has been handled.
170 // otherwise - N should be replaced by the returned Operand.
172 SDValue visitTokenFactor(SDNode *N);
173 SDValue visitMERGE_VALUES(SDNode *N);
174 SDValue visitADD(SDNode *N);
175 SDValue visitSUB(SDNode *N);
176 SDValue visitADDC(SDNode *N);
177 SDValue visitSUBC(SDNode *N);
178 SDValue visitADDE(SDNode *N);
179 SDValue visitSUBE(SDNode *N);
180 SDValue visitMUL(SDNode *N);
181 SDValue visitSDIV(SDNode *N);
182 SDValue visitUDIV(SDNode *N);
183 SDValue visitSREM(SDNode *N);
184 SDValue visitUREM(SDNode *N);
185 SDValue visitMULHU(SDNode *N);
186 SDValue visitMULHS(SDNode *N);
187 SDValue visitSMUL_LOHI(SDNode *N);
188 SDValue visitUMUL_LOHI(SDNode *N);
189 SDValue visitSMULO(SDNode *N);
190 SDValue visitUMULO(SDNode *N);
191 SDValue visitSDIVREM(SDNode *N);
192 SDValue visitUDIVREM(SDNode *N);
193 SDValue visitAND(SDNode *N);
194 SDValue visitOR(SDNode *N);
195 SDValue visitXOR(SDNode *N);
196 SDValue SimplifyVBinOp(SDNode *N);
197 SDValue SimplifyVUnaryOp(SDNode *N);
198 SDValue visitSHL(SDNode *N);
199 SDValue visitSRA(SDNode *N);
200 SDValue visitSRL(SDNode *N);
201 SDValue visitCTLZ(SDNode *N);
202 SDValue visitCTLZ_ZERO_UNDEF(SDNode *N);
203 SDValue visitCTTZ(SDNode *N);
204 SDValue visitCTTZ_ZERO_UNDEF(SDNode *N);
205 SDValue visitCTPOP(SDNode *N);
206 SDValue visitSELECT(SDNode *N);
207 SDValue visitSELECT_CC(SDNode *N);
208 SDValue visitSETCC(SDNode *N);
209 SDValue visitSIGN_EXTEND(SDNode *N);
210 SDValue visitZERO_EXTEND(SDNode *N);
211 SDValue visitANY_EXTEND(SDNode *N);
212 SDValue visitSIGN_EXTEND_INREG(SDNode *N);
213 SDValue visitTRUNCATE(SDNode *N);
214 SDValue visitBITCAST(SDNode *N);
215 SDValue visitBUILD_PAIR(SDNode *N);
216 SDValue visitFADD(SDNode *N);
217 SDValue visitFSUB(SDNode *N);
218 SDValue visitFMUL(SDNode *N);
219 SDValue visitFMA(SDNode *N);
220 SDValue visitFDIV(SDNode *N);
221 SDValue visitFREM(SDNode *N);
222 SDValue visitFCOPYSIGN(SDNode *N);
223 SDValue visitSINT_TO_FP(SDNode *N);
224 SDValue visitUINT_TO_FP(SDNode *N);
225 SDValue visitFP_TO_SINT(SDNode *N);
226 SDValue visitFP_TO_UINT(SDNode *N);
227 SDValue visitFP_ROUND(SDNode *N);
228 SDValue visitFP_ROUND_INREG(SDNode *N);
229 SDValue visitFP_EXTEND(SDNode *N);
230 SDValue visitFNEG(SDNode *N);
231 SDValue visitFABS(SDNode *N);
232 SDValue visitFCEIL(SDNode *N);
233 SDValue visitFTRUNC(SDNode *N);
234 SDValue visitFFLOOR(SDNode *N);
235 SDValue visitBRCOND(SDNode *N);
236 SDValue visitBR_CC(SDNode *N);
237 SDValue visitLOAD(SDNode *N);
238 SDValue visitSTORE(SDNode *N);
239 SDValue visitINSERT_VECTOR_ELT(SDNode *N);
240 SDValue visitEXTRACT_VECTOR_ELT(SDNode *N);
241 SDValue visitBUILD_VECTOR(SDNode *N);
242 SDValue visitCONCAT_VECTORS(SDNode *N);
243 SDValue visitEXTRACT_SUBVECTOR(SDNode *N);
244 SDValue visitVECTOR_SHUFFLE(SDNode *N);
245 SDValue visitMEMBARRIER(SDNode *N);
247 SDValue XformToShuffleWithZero(SDNode *N);
248 SDValue ReassociateOps(unsigned Opc, DebugLoc DL, SDValue LHS, SDValue RHS);
250 SDValue visitShiftByConstant(SDNode *N, unsigned Amt);
252 bool SimplifySelectOps(SDNode *SELECT, SDValue LHS, SDValue RHS);
253 SDValue SimplifyBinOpWithSameOpcodeHands(SDNode *N);
254 SDValue SimplifySelect(DebugLoc DL, SDValue N0, SDValue N1, SDValue N2);
255 SDValue SimplifySelectCC(DebugLoc DL, SDValue N0, SDValue N1, SDValue N2,
256 SDValue N3, ISD::CondCode CC,
257 bool NotExtCompare = false);
258 SDValue SimplifySetCC(EVT VT, SDValue N0, SDValue N1, ISD::CondCode Cond,
259 DebugLoc DL, bool foldBooleans = true);
260 SDValue SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
262 SDValue CombineConsecutiveLoads(SDNode *N, EVT VT);
263 SDValue ConstantFoldBITCASTofBUILD_VECTOR(SDNode *, EVT);
264 SDValue BuildSDIV(SDNode *N);
265 SDValue BuildUDIV(SDNode *N);
266 SDValue MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
267 bool DemandHighBits = true);
268 SDValue MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1);
269 SDNode *MatchRotate(SDValue LHS, SDValue RHS, DebugLoc DL);
270 SDValue ReduceLoadWidth(SDNode *N);
271 SDValue ReduceLoadOpStoreWidth(SDNode *N);
272 SDValue TransformFPLoadStorePair(SDNode *N);
273 SDValue reduceBuildVecExtToExtBuildVec(SDNode *N);
274 SDValue reduceBuildVecConvertToConvertBuildVec(SDNode *N);
276 SDValue GetDemandedBits(SDValue V, const APInt &Mask);
278 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
279 /// looking for aliasing nodes and adding them to the Aliases vector.
280 void GatherAllAliases(SDNode *N, SDValue OriginalChain,
281 SmallVector<SDValue, 8> &Aliases);
283 /// isAlias - Return true if there is any possibility that the two addresses
285 bool isAlias(SDValue Ptr1, int64_t Size1,
286 const Value *SrcValue1, int SrcValueOffset1,
287 unsigned SrcValueAlign1,
288 const MDNode *TBAAInfo1,
289 SDValue Ptr2, int64_t Size2,
290 const Value *SrcValue2, int SrcValueOffset2,
291 unsigned SrcValueAlign2,
292 const MDNode *TBAAInfo2) const;
294 /// FindAliasInfo - Extracts the relevant alias information from the memory
295 /// node. Returns true if the operand was a load.
296 bool FindAliasInfo(SDNode *N,
297 SDValue &Ptr, int64_t &Size,
298 const Value *&SrcValue, int &SrcValueOffset,
299 unsigned &SrcValueAlignment,
300 const MDNode *&TBAAInfo) const;
302 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes,
303 /// looking for a better chain (aliasing node.)
304 SDValue FindBetterChain(SDNode *N, SDValue Chain);
306 /// Merge consecutive store operations into a wide store.
307 /// This optimization uses wide integers or vectors when possible.
308 /// \return True if some memory operations were changed.
309 bool MergeConsecutiveStores(StoreSDNode *N);
312 DAGCombiner(SelectionDAG &D, AliasAnalysis &A, CodeGenOpt::Level OL)
313 : DAG(D), TLI(D.getTargetLoweringInfo()), Level(BeforeLegalizeTypes),
314 OptLevel(OL), LegalOperations(false), LegalTypes(false), AA(A) {}
316 /// Run - runs the dag combiner on all nodes in the work list
317 void Run(CombineLevel AtLevel);
319 SelectionDAG &getDAG() const { return DAG; }
321 /// getShiftAmountTy - Returns a type large enough to hold any valid
322 /// shift amount - before type legalization these can be huge.
323 EVT getShiftAmountTy(EVT LHSTy) {
324 return LegalTypes ? TLI.getShiftAmountTy(LHSTy) : TLI.getPointerTy();
327 /// isTypeLegal - This method returns true if we are running before type
328 /// legalization or if the specified VT is legal.
329 bool isTypeLegal(const EVT &VT) {
330 if (!LegalTypes) return true;
331 return TLI.isTypeLegal(VT);
338 /// WorkListRemover - This class is a DAGUpdateListener that removes any deleted
339 /// nodes from the worklist.
340 class WorkListRemover : public SelectionDAG::DAGUpdateListener {
343 explicit WorkListRemover(DAGCombiner &dc)
344 : SelectionDAG::DAGUpdateListener(dc.getDAG()), DC(dc) {}
346 virtual void NodeDeleted(SDNode *N, SDNode *E) {
347 DC.removeFromWorkList(N);
352 //===----------------------------------------------------------------------===//
353 // TargetLowering::DAGCombinerInfo implementation
354 //===----------------------------------------------------------------------===//
356 void TargetLowering::DAGCombinerInfo::AddToWorklist(SDNode *N) {
357 ((DAGCombiner*)DC)->AddToWorkList(N);
360 void TargetLowering::DAGCombinerInfo::RemoveFromWorklist(SDNode *N) {
361 ((DAGCombiner*)DC)->removeFromWorkList(N);
364 SDValue TargetLowering::DAGCombinerInfo::
365 CombineTo(SDNode *N, const std::vector<SDValue> &To, bool AddTo) {
366 return ((DAGCombiner*)DC)->CombineTo(N, &To[0], To.size(), AddTo);
369 SDValue TargetLowering::DAGCombinerInfo::
370 CombineTo(SDNode *N, SDValue Res, bool AddTo) {
371 return ((DAGCombiner*)DC)->CombineTo(N, Res, AddTo);
375 SDValue TargetLowering::DAGCombinerInfo::
376 CombineTo(SDNode *N, SDValue Res0, SDValue Res1, bool AddTo) {
377 return ((DAGCombiner*)DC)->CombineTo(N, Res0, Res1, AddTo);
380 void TargetLowering::DAGCombinerInfo::
381 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
382 return ((DAGCombiner*)DC)->CommitTargetLoweringOpt(TLO);
385 //===----------------------------------------------------------------------===//
387 //===----------------------------------------------------------------------===//
389 /// isNegatibleForFree - Return 1 if we can compute the negated form of the
390 /// specified expression for the same cost as the expression itself, or 2 if we
391 /// can compute the negated form more cheaply than the expression itself.
392 static char isNegatibleForFree(SDValue Op, bool LegalOperations,
393 const TargetLowering &TLI,
394 const TargetOptions *Options,
395 unsigned Depth = 0) {
396 // fneg is removable even if it has multiple uses.
397 if (Op.getOpcode() == ISD::FNEG) return 2;
399 // Don't allow anything with multiple uses.
400 if (!Op.hasOneUse()) return 0;
402 // Don't recurse exponentially.
403 if (Depth > 6) return 0;
405 switch (Op.getOpcode()) {
406 default: return false;
407 case ISD::ConstantFP:
408 // Don't invert constant FP values after legalize. The negated constant
409 // isn't necessarily legal.
410 return LegalOperations ? 0 : 1;
412 // FIXME: determine better conditions for this xform.
413 if (!Options->UnsafeFPMath) return 0;
415 // After operation legalization, it might not be legal to create new FSUBs.
416 if (LegalOperations &&
417 !TLI.isOperationLegalOrCustom(ISD::FSUB, Op.getValueType()))
420 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
421 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
424 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
425 return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
428 // We can't turn -(A-B) into B-A when we honor signed zeros.
429 if (!Options->UnsafeFPMath) return 0;
431 // fold (fneg (fsub A, B)) -> (fsub B, A)
436 if (Options->HonorSignDependentRoundingFPMath()) return 0;
438 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y) or (fmul X, (fneg Y))
439 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
443 return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
449 return isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI, Options,
454 /// GetNegatedExpression - If isNegatibleForFree returns true, this function
455 /// returns the newly negated expression.
456 static SDValue GetNegatedExpression(SDValue Op, SelectionDAG &DAG,
457 bool LegalOperations, unsigned Depth = 0) {
458 // fneg is removable even if it has multiple uses.
459 if (Op.getOpcode() == ISD::FNEG) return Op.getOperand(0);
461 // Don't allow anything with multiple uses.
462 assert(Op.hasOneUse() && "Unknown reuse!");
464 assert(Depth <= 6 && "GetNegatedExpression doesn't match isNegatibleForFree");
465 switch (Op.getOpcode()) {
466 default: llvm_unreachable("Unknown code");
467 case ISD::ConstantFP: {
468 APFloat V = cast<ConstantFPSDNode>(Op)->getValueAPF();
470 return DAG.getConstantFP(V, Op.getValueType());
473 // FIXME: determine better conditions for this xform.
474 assert(DAG.getTarget().Options.UnsafeFPMath);
476 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
477 if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
478 DAG.getTargetLoweringInfo(),
479 &DAG.getTarget().Options, Depth+1))
480 return DAG.getNode(ISD::FSUB, Op.getDebugLoc(), Op.getValueType(),
481 GetNegatedExpression(Op.getOperand(0), DAG,
482 LegalOperations, Depth+1),
484 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
485 return DAG.getNode(ISD::FSUB, Op.getDebugLoc(), Op.getValueType(),
486 GetNegatedExpression(Op.getOperand(1), DAG,
487 LegalOperations, Depth+1),
490 // We can't turn -(A-B) into B-A when we honor signed zeros.
491 assert(DAG.getTarget().Options.UnsafeFPMath);
493 // fold (fneg (fsub 0, B)) -> B
494 if (ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(Op.getOperand(0)))
495 if (N0CFP->getValueAPF().isZero())
496 return Op.getOperand(1);
498 // fold (fneg (fsub A, B)) -> (fsub B, A)
499 return DAG.getNode(ISD::FSUB, Op.getDebugLoc(), Op.getValueType(),
500 Op.getOperand(1), Op.getOperand(0));
504 assert(!DAG.getTarget().Options.HonorSignDependentRoundingFPMath());
506 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y)
507 if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
508 DAG.getTargetLoweringInfo(),
509 &DAG.getTarget().Options, Depth+1))
510 return DAG.getNode(Op.getOpcode(), Op.getDebugLoc(), Op.getValueType(),
511 GetNegatedExpression(Op.getOperand(0), DAG,
512 LegalOperations, Depth+1),
515 // fold (fneg (fmul X, Y)) -> (fmul X, (fneg Y))
516 return DAG.getNode(Op.getOpcode(), Op.getDebugLoc(), Op.getValueType(),
518 GetNegatedExpression(Op.getOperand(1), DAG,
519 LegalOperations, Depth+1));
523 return DAG.getNode(Op.getOpcode(), Op.getDebugLoc(), Op.getValueType(),
524 GetNegatedExpression(Op.getOperand(0), DAG,
525 LegalOperations, Depth+1));
527 return DAG.getNode(ISD::FP_ROUND, Op.getDebugLoc(), Op.getValueType(),
528 GetNegatedExpression(Op.getOperand(0), DAG,
529 LegalOperations, Depth+1),
535 // isSetCCEquivalent - Return true if this node is a setcc, or is a select_cc
536 // that selects between the values 1 and 0, making it equivalent to a setcc.
537 // Also, set the incoming LHS, RHS, and CC references to the appropriate
538 // nodes based on the type of node we are checking. This simplifies life a
539 // bit for the callers.
540 static bool isSetCCEquivalent(SDValue N, SDValue &LHS, SDValue &RHS,
542 if (N.getOpcode() == ISD::SETCC) {
543 LHS = N.getOperand(0);
544 RHS = N.getOperand(1);
545 CC = N.getOperand(2);
548 if (N.getOpcode() == ISD::SELECT_CC &&
549 N.getOperand(2).getOpcode() == ISD::Constant &&
550 N.getOperand(3).getOpcode() == ISD::Constant &&
551 cast<ConstantSDNode>(N.getOperand(2))->getAPIntValue() == 1 &&
552 cast<ConstantSDNode>(N.getOperand(3))->isNullValue()) {
553 LHS = N.getOperand(0);
554 RHS = N.getOperand(1);
555 CC = N.getOperand(4);
561 // isOneUseSetCC - Return true if this is a SetCC-equivalent operation with only
562 // one use. If this is true, it allows the users to invert the operation for
563 // free when it is profitable to do so.
564 static bool isOneUseSetCC(SDValue N) {
566 if (isSetCCEquivalent(N, N0, N1, N2) && N.getNode()->hasOneUse())
571 SDValue DAGCombiner::ReassociateOps(unsigned Opc, DebugLoc DL,
572 SDValue N0, SDValue N1) {
573 EVT VT = N0.getValueType();
574 if (N0.getOpcode() == Opc && isa<ConstantSDNode>(N0.getOperand(1))) {
575 if (isa<ConstantSDNode>(N1)) {
576 // reassoc. (op (op x, c1), c2) -> (op x, (op c1, c2))
578 DAG.FoldConstantArithmetic(Opc, VT,
579 cast<ConstantSDNode>(N0.getOperand(1)),
580 cast<ConstantSDNode>(N1));
581 return DAG.getNode(Opc, DL, VT, N0.getOperand(0), OpNode);
583 if (N0.hasOneUse()) {
584 // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one use
585 SDValue OpNode = DAG.getNode(Opc, N0.getDebugLoc(), VT,
586 N0.getOperand(0), N1);
587 AddToWorkList(OpNode.getNode());
588 return DAG.getNode(Opc, DL, VT, OpNode, N0.getOperand(1));
592 if (N1.getOpcode() == Opc && isa<ConstantSDNode>(N1.getOperand(1))) {
593 if (isa<ConstantSDNode>(N0)) {
594 // reassoc. (op c2, (op x, c1)) -> (op x, (op c1, c2))
596 DAG.FoldConstantArithmetic(Opc, VT,
597 cast<ConstantSDNode>(N1.getOperand(1)),
598 cast<ConstantSDNode>(N0));
599 return DAG.getNode(Opc, DL, VT, N1.getOperand(0), OpNode);
601 if (N1.hasOneUse()) {
602 // reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) iff x+c1 has one use
603 SDValue OpNode = DAG.getNode(Opc, N0.getDebugLoc(), VT,
604 N1.getOperand(0), N0);
605 AddToWorkList(OpNode.getNode());
606 return DAG.getNode(Opc, DL, VT, OpNode, N1.getOperand(1));
613 SDValue DAGCombiner::CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
615 assert(N->getNumValues() == NumTo && "Broken CombineTo call!");
617 DEBUG(dbgs() << "\nReplacing.1 ";
619 dbgs() << "\nWith: ";
620 To[0].getNode()->dump(&DAG);
621 dbgs() << " and " << NumTo-1 << " other values\n";
622 for (unsigned i = 0, e = NumTo; i != e; ++i)
623 assert((!To[i].getNode() ||
624 N->getValueType(i) == To[i].getValueType()) &&
625 "Cannot combine value to value of different type!"));
626 WorkListRemover DeadNodes(*this);
627 DAG.ReplaceAllUsesWith(N, To);
629 // Push the new nodes and any users onto the worklist
630 for (unsigned i = 0, e = NumTo; i != e; ++i) {
631 if (To[i].getNode()) {
632 AddToWorkList(To[i].getNode());
633 AddUsersToWorkList(To[i].getNode());
638 // Finally, if the node is now dead, remove it from the graph. The node
639 // may not be dead if the replacement process recursively simplified to
640 // something else needing this node.
641 if (N->use_empty()) {
642 // Nodes can be reintroduced into the worklist. Make sure we do not
643 // process a node that has been replaced.
644 removeFromWorkList(N);
646 // Finally, since the node is now dead, remove it from the graph.
649 return SDValue(N, 0);
653 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
654 // Replace all uses. If any nodes become isomorphic to other nodes and
655 // are deleted, make sure to remove them from our worklist.
656 WorkListRemover DeadNodes(*this);
657 DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New);
659 // Push the new node and any (possibly new) users onto the worklist.
660 AddToWorkList(TLO.New.getNode());
661 AddUsersToWorkList(TLO.New.getNode());
663 // Finally, if the node is now dead, remove it from the graph. The node
664 // may not be dead if the replacement process recursively simplified to
665 // something else needing this node.
666 if (TLO.Old.getNode()->use_empty()) {
667 removeFromWorkList(TLO.Old.getNode());
669 // If the operands of this node are only used by the node, they will now
670 // be dead. Make sure to visit them first to delete dead nodes early.
671 for (unsigned i = 0, e = TLO.Old.getNode()->getNumOperands(); i != e; ++i)
672 if (TLO.Old.getNode()->getOperand(i).getNode()->hasOneUse())
673 AddToWorkList(TLO.Old.getNode()->getOperand(i).getNode());
675 DAG.DeleteNode(TLO.Old.getNode());
679 /// SimplifyDemandedBits - Check the specified integer node value to see if
680 /// it can be simplified or if things it uses can be simplified by bit
681 /// propagation. If so, return true.
682 bool DAGCombiner::SimplifyDemandedBits(SDValue Op, const APInt &Demanded) {
683 TargetLowering::TargetLoweringOpt TLO(DAG, LegalTypes, LegalOperations);
684 APInt KnownZero, KnownOne;
685 if (!TLI.SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO))
689 AddToWorkList(Op.getNode());
691 // Replace the old value with the new one.
693 DEBUG(dbgs() << "\nReplacing.2 ";
694 TLO.Old.getNode()->dump(&DAG);
695 dbgs() << "\nWith: ";
696 TLO.New.getNode()->dump(&DAG);
699 CommitTargetLoweringOpt(TLO);
703 void DAGCombiner::ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad) {
704 DebugLoc dl = Load->getDebugLoc();
705 EVT VT = Load->getValueType(0);
706 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, VT, SDValue(ExtLoad, 0));
708 DEBUG(dbgs() << "\nReplacing.9 ";
710 dbgs() << "\nWith: ";
711 Trunc.getNode()->dump(&DAG);
713 WorkListRemover DeadNodes(*this);
714 DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 0), Trunc);
715 DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 1), SDValue(ExtLoad, 1));
716 removeFromWorkList(Load);
717 DAG.DeleteNode(Load);
718 AddToWorkList(Trunc.getNode());
721 SDValue DAGCombiner::PromoteOperand(SDValue Op, EVT PVT, bool &Replace) {
723 DebugLoc dl = Op.getDebugLoc();
724 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Op)) {
725 EVT MemVT = LD->getMemoryVT();
726 ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
727 ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT) ? ISD::ZEXTLOAD
729 : LD->getExtensionType();
731 return DAG.getExtLoad(ExtType, dl, PVT,
732 LD->getChain(), LD->getBasePtr(),
733 LD->getPointerInfo(),
734 MemVT, LD->isVolatile(),
735 LD->isNonTemporal(), LD->getAlignment());
738 unsigned Opc = Op.getOpcode();
741 case ISD::AssertSext:
742 return DAG.getNode(ISD::AssertSext, dl, PVT,
743 SExtPromoteOperand(Op.getOperand(0), PVT),
745 case ISD::AssertZext:
746 return DAG.getNode(ISD::AssertZext, dl, PVT,
747 ZExtPromoteOperand(Op.getOperand(0), PVT),
749 case ISD::Constant: {
751 Op.getValueType().isByteSized() ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
752 return DAG.getNode(ExtOpc, dl, PVT, Op);
756 if (!TLI.isOperationLegal(ISD::ANY_EXTEND, PVT))
758 return DAG.getNode(ISD::ANY_EXTEND, dl, PVT, Op);
761 SDValue DAGCombiner::SExtPromoteOperand(SDValue Op, EVT PVT) {
762 if (!TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, PVT))
764 EVT OldVT = Op.getValueType();
765 DebugLoc dl = Op.getDebugLoc();
766 bool Replace = false;
767 SDValue NewOp = PromoteOperand(Op, PVT, Replace);
768 if (NewOp.getNode() == 0)
770 AddToWorkList(NewOp.getNode());
773 ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
774 return DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, NewOp.getValueType(), NewOp,
775 DAG.getValueType(OldVT));
778 SDValue DAGCombiner::ZExtPromoteOperand(SDValue Op, EVT PVT) {
779 EVT OldVT = Op.getValueType();
780 DebugLoc dl = Op.getDebugLoc();
781 bool Replace = false;
782 SDValue NewOp = PromoteOperand(Op, PVT, Replace);
783 if (NewOp.getNode() == 0)
785 AddToWorkList(NewOp.getNode());
788 ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
789 return DAG.getZeroExtendInReg(NewOp, dl, OldVT);
792 /// PromoteIntBinOp - Promote the specified integer binary operation if the
793 /// target indicates it is beneficial. e.g. On x86, it's usually better to
794 /// promote i16 operations to i32 since i16 instructions are longer.
795 SDValue DAGCombiner::PromoteIntBinOp(SDValue Op) {
796 if (!LegalOperations)
799 EVT VT = Op.getValueType();
800 if (VT.isVector() || !VT.isInteger())
803 // If operation type is 'undesirable', e.g. i16 on x86, consider
805 unsigned Opc = Op.getOpcode();
806 if (TLI.isTypeDesirableForOp(Opc, VT))
810 // Consult target whether it is a good idea to promote this operation and
811 // what's the right type to promote it to.
812 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
813 assert(PVT != VT && "Don't know what type to promote to!");
815 bool Replace0 = false;
816 SDValue N0 = Op.getOperand(0);
817 SDValue NN0 = PromoteOperand(N0, PVT, Replace0);
818 if (NN0.getNode() == 0)
821 bool Replace1 = false;
822 SDValue N1 = Op.getOperand(1);
827 NN1 = PromoteOperand(N1, PVT, Replace1);
828 if (NN1.getNode() == 0)
832 AddToWorkList(NN0.getNode());
834 AddToWorkList(NN1.getNode());
837 ReplaceLoadWithPromotedLoad(N0.getNode(), NN0.getNode());
839 ReplaceLoadWithPromotedLoad(N1.getNode(), NN1.getNode());
841 DEBUG(dbgs() << "\nPromoting ";
842 Op.getNode()->dump(&DAG));
843 DebugLoc dl = Op.getDebugLoc();
844 return DAG.getNode(ISD::TRUNCATE, dl, VT,
845 DAG.getNode(Opc, dl, PVT, NN0, NN1));
850 /// PromoteIntShiftOp - Promote the specified integer shift operation if the
851 /// target indicates it is beneficial. e.g. On x86, it's usually better to
852 /// promote i16 operations to i32 since i16 instructions are longer.
853 SDValue DAGCombiner::PromoteIntShiftOp(SDValue Op) {
854 if (!LegalOperations)
857 EVT VT = Op.getValueType();
858 if (VT.isVector() || !VT.isInteger())
861 // If operation type is 'undesirable', e.g. i16 on x86, consider
863 unsigned Opc = Op.getOpcode();
864 if (TLI.isTypeDesirableForOp(Opc, VT))
868 // Consult target whether it is a good idea to promote this operation and
869 // what's the right type to promote it to.
870 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
871 assert(PVT != VT && "Don't know what type to promote to!");
873 bool Replace = false;
874 SDValue N0 = Op.getOperand(0);
876 N0 = SExtPromoteOperand(Op.getOperand(0), PVT);
877 else if (Opc == ISD::SRL)
878 N0 = ZExtPromoteOperand(Op.getOperand(0), PVT);
880 N0 = PromoteOperand(N0, PVT, Replace);
881 if (N0.getNode() == 0)
884 AddToWorkList(N0.getNode());
886 ReplaceLoadWithPromotedLoad(Op.getOperand(0).getNode(), N0.getNode());
888 DEBUG(dbgs() << "\nPromoting ";
889 Op.getNode()->dump(&DAG));
890 DebugLoc dl = Op.getDebugLoc();
891 return DAG.getNode(ISD::TRUNCATE, dl, VT,
892 DAG.getNode(Opc, dl, PVT, N0, Op.getOperand(1)));
897 SDValue DAGCombiner::PromoteExtend(SDValue Op) {
898 if (!LegalOperations)
901 EVT VT = Op.getValueType();
902 if (VT.isVector() || !VT.isInteger())
905 // If operation type is 'undesirable', e.g. i16 on x86, consider
907 unsigned Opc = Op.getOpcode();
908 if (TLI.isTypeDesirableForOp(Opc, VT))
912 // Consult target whether it is a good idea to promote this operation and
913 // what's the right type to promote it to.
914 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
915 assert(PVT != VT && "Don't know what type to promote to!");
916 // fold (aext (aext x)) -> (aext x)
917 // fold (aext (zext x)) -> (zext x)
918 // fold (aext (sext x)) -> (sext x)
919 DEBUG(dbgs() << "\nPromoting ";
920 Op.getNode()->dump(&DAG));
921 return DAG.getNode(Op.getOpcode(), Op.getDebugLoc(), VT, Op.getOperand(0));
926 bool DAGCombiner::PromoteLoad(SDValue Op) {
927 if (!LegalOperations)
930 EVT VT = Op.getValueType();
931 if (VT.isVector() || !VT.isInteger())
934 // If operation type is 'undesirable', e.g. i16 on x86, consider
936 unsigned Opc = Op.getOpcode();
937 if (TLI.isTypeDesirableForOp(Opc, VT))
941 // Consult target whether it is a good idea to promote this operation and
942 // what's the right type to promote it to.
943 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
944 assert(PVT != VT && "Don't know what type to promote to!");
946 DebugLoc dl = Op.getDebugLoc();
947 SDNode *N = Op.getNode();
948 LoadSDNode *LD = cast<LoadSDNode>(N);
949 EVT MemVT = LD->getMemoryVT();
950 ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
951 ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT) ? ISD::ZEXTLOAD
953 : LD->getExtensionType();
954 SDValue NewLD = DAG.getExtLoad(ExtType, dl, PVT,
955 LD->getChain(), LD->getBasePtr(),
956 LD->getPointerInfo(),
957 MemVT, LD->isVolatile(),
958 LD->isNonTemporal(), LD->getAlignment());
959 SDValue Result = DAG.getNode(ISD::TRUNCATE, dl, VT, NewLD);
961 DEBUG(dbgs() << "\nPromoting ";
964 Result.getNode()->dump(&DAG);
966 WorkListRemover DeadNodes(*this);
967 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result);
968 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), NewLD.getValue(1));
969 removeFromWorkList(N);
971 AddToWorkList(Result.getNode());
978 //===----------------------------------------------------------------------===//
979 // Main DAG Combiner implementation
980 //===----------------------------------------------------------------------===//
982 void DAGCombiner::Run(CombineLevel AtLevel) {
983 // set the instance variables, so that the various visit routines may use it.
985 LegalOperations = Level >= AfterLegalizeVectorOps;
986 LegalTypes = Level >= AfterLegalizeTypes;
988 // Add all the dag nodes to the worklist.
989 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
990 E = DAG.allnodes_end(); I != E; ++I)
993 // Create a dummy node (which is not added to allnodes), that adds a reference
994 // to the root node, preventing it from being deleted, and tracking any
995 // changes of the root.
996 HandleSDNode Dummy(DAG.getRoot());
998 // The root of the dag may dangle to deleted nodes until the dag combiner is
999 // done. Set it to null to avoid confusion.
1000 DAG.setRoot(SDValue());
1002 // while the worklist isn't empty, find a node and
1003 // try and combine it.
1004 while (!WorkListContents.empty()) {
1006 // The WorkListOrder holds the SDNodes in order, but it may contain duplicates.
1007 // In order to avoid a linear scan, we use a set (O(log N)) to hold what the
1008 // worklist *should* contain, and check the node we want to visit is should
1009 // actually be visited.
1011 N = WorkListOrder.pop_back_val();
1012 } while (!WorkListContents.erase(N));
1014 // If N has no uses, it is dead. Make sure to revisit all N's operands once
1015 // N is deleted from the DAG, since they too may now be dead or may have a
1016 // reduced number of uses, allowing other xforms.
1017 if (N->use_empty() && N != &Dummy) {
1018 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1019 AddToWorkList(N->getOperand(i).getNode());
1025 SDValue RV = combine(N);
1027 if (RV.getNode() == 0)
1032 // If we get back the same node we passed in, rather than a new node or
1033 // zero, we know that the node must have defined multiple values and
1034 // CombineTo was used. Since CombineTo takes care of the worklist
1035 // mechanics for us, we have no work to do in this case.
1036 if (RV.getNode() == N)
1039 assert(N->getOpcode() != ISD::DELETED_NODE &&
1040 RV.getNode()->getOpcode() != ISD::DELETED_NODE &&
1041 "Node was deleted but visit returned new node!");
1043 DEBUG(dbgs() << "\nReplacing.3 ";
1045 dbgs() << "\nWith: ";
1046 RV.getNode()->dump(&DAG);
1049 // Transfer debug value.
1050 DAG.TransferDbgValues(SDValue(N, 0), RV);
1051 WorkListRemover DeadNodes(*this);
1052 if (N->getNumValues() == RV.getNode()->getNumValues())
1053 DAG.ReplaceAllUsesWith(N, RV.getNode());
1055 assert(N->getValueType(0) == RV.getValueType() &&
1056 N->getNumValues() == 1 && "Type mismatch");
1058 DAG.ReplaceAllUsesWith(N, &OpV);
1061 // Push the new node and any users onto the worklist
1062 AddToWorkList(RV.getNode());
1063 AddUsersToWorkList(RV.getNode());
1065 // Add any uses of the old node to the worklist in case this node is the
1066 // last one that uses them. They may become dead after this node is
1068 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1069 AddToWorkList(N->getOperand(i).getNode());
1071 // Finally, if the node is now dead, remove it from the graph. The node
1072 // may not be dead if the replacement process recursively simplified to
1073 // something else needing this node.
1074 if (N->use_empty()) {
1075 // Nodes can be reintroduced into the worklist. Make sure we do not
1076 // process a node that has been replaced.
1077 removeFromWorkList(N);
1079 // Finally, since the node is now dead, remove it from the graph.
1084 // If the root changed (e.g. it was a dead load, update the root).
1085 DAG.setRoot(Dummy.getValue());
1086 DAG.RemoveDeadNodes();
1089 SDValue DAGCombiner::visit(SDNode *N) {
1090 switch (N->getOpcode()) {
1092 case ISD::TokenFactor: return visitTokenFactor(N);
1093 case ISD::MERGE_VALUES: return visitMERGE_VALUES(N);
1094 case ISD::ADD: return visitADD(N);
1095 case ISD::SUB: return visitSUB(N);
1096 case ISD::ADDC: return visitADDC(N);
1097 case ISD::SUBC: return visitSUBC(N);
1098 case ISD::ADDE: return visitADDE(N);
1099 case ISD::SUBE: return visitSUBE(N);
1100 case ISD::MUL: return visitMUL(N);
1101 case ISD::SDIV: return visitSDIV(N);
1102 case ISD::UDIV: return visitUDIV(N);
1103 case ISD::SREM: return visitSREM(N);
1104 case ISD::UREM: return visitUREM(N);
1105 case ISD::MULHU: return visitMULHU(N);
1106 case ISD::MULHS: return visitMULHS(N);
1107 case ISD::SMUL_LOHI: return visitSMUL_LOHI(N);
1108 case ISD::UMUL_LOHI: return visitUMUL_LOHI(N);
1109 case ISD::SMULO: return visitSMULO(N);
1110 case ISD::UMULO: return visitUMULO(N);
1111 case ISD::SDIVREM: return visitSDIVREM(N);
1112 case ISD::UDIVREM: return visitUDIVREM(N);
1113 case ISD::AND: return visitAND(N);
1114 case ISD::OR: return visitOR(N);
1115 case ISD::XOR: return visitXOR(N);
1116 case ISD::SHL: return visitSHL(N);
1117 case ISD::SRA: return visitSRA(N);
1118 case ISD::SRL: return visitSRL(N);
1119 case ISD::CTLZ: return visitCTLZ(N);
1120 case ISD::CTLZ_ZERO_UNDEF: return visitCTLZ_ZERO_UNDEF(N);
1121 case ISD::CTTZ: return visitCTTZ(N);
1122 case ISD::CTTZ_ZERO_UNDEF: return visitCTTZ_ZERO_UNDEF(N);
1123 case ISD::CTPOP: return visitCTPOP(N);
1124 case ISD::SELECT: return visitSELECT(N);
1125 case ISD::SELECT_CC: return visitSELECT_CC(N);
1126 case ISD::SETCC: return visitSETCC(N);
1127 case ISD::SIGN_EXTEND: return visitSIGN_EXTEND(N);
1128 case ISD::ZERO_EXTEND: return visitZERO_EXTEND(N);
1129 case ISD::ANY_EXTEND: return visitANY_EXTEND(N);
1130 case ISD::SIGN_EXTEND_INREG: return visitSIGN_EXTEND_INREG(N);
1131 case ISD::TRUNCATE: return visitTRUNCATE(N);
1132 case ISD::BITCAST: return visitBITCAST(N);
1133 case ISD::BUILD_PAIR: return visitBUILD_PAIR(N);
1134 case ISD::FADD: return visitFADD(N);
1135 case ISD::FSUB: return visitFSUB(N);
1136 case ISD::FMUL: return visitFMUL(N);
1137 case ISD::FMA: return visitFMA(N);
1138 case ISD::FDIV: return visitFDIV(N);
1139 case ISD::FREM: return visitFREM(N);
1140 case ISD::FCOPYSIGN: return visitFCOPYSIGN(N);
1141 case ISD::SINT_TO_FP: return visitSINT_TO_FP(N);
1142 case ISD::UINT_TO_FP: return visitUINT_TO_FP(N);
1143 case ISD::FP_TO_SINT: return visitFP_TO_SINT(N);
1144 case ISD::FP_TO_UINT: return visitFP_TO_UINT(N);
1145 case ISD::FP_ROUND: return visitFP_ROUND(N);
1146 case ISD::FP_ROUND_INREG: return visitFP_ROUND_INREG(N);
1147 case ISD::FP_EXTEND: return visitFP_EXTEND(N);
1148 case ISD::FNEG: return visitFNEG(N);
1149 case ISD::FABS: return visitFABS(N);
1150 case ISD::FFLOOR: return visitFFLOOR(N);
1151 case ISD::FCEIL: return visitFCEIL(N);
1152 case ISD::FTRUNC: return visitFTRUNC(N);
1153 case ISD::BRCOND: return visitBRCOND(N);
1154 case ISD::BR_CC: return visitBR_CC(N);
1155 case ISD::LOAD: return visitLOAD(N);
1156 case ISD::STORE: return visitSTORE(N);
1157 case ISD::INSERT_VECTOR_ELT: return visitINSERT_VECTOR_ELT(N);
1158 case ISD::EXTRACT_VECTOR_ELT: return visitEXTRACT_VECTOR_ELT(N);
1159 case ISD::BUILD_VECTOR: return visitBUILD_VECTOR(N);
1160 case ISD::CONCAT_VECTORS: return visitCONCAT_VECTORS(N);
1161 case ISD::EXTRACT_SUBVECTOR: return visitEXTRACT_SUBVECTOR(N);
1162 case ISD::VECTOR_SHUFFLE: return visitVECTOR_SHUFFLE(N);
1163 case ISD::MEMBARRIER: return visitMEMBARRIER(N);
1168 SDValue DAGCombiner::combine(SDNode *N) {
1169 SDValue RV = visit(N);
1171 // If nothing happened, try a target-specific DAG combine.
1172 if (RV.getNode() == 0) {
1173 assert(N->getOpcode() != ISD::DELETED_NODE &&
1174 "Node was deleted but visit returned NULL!");
1176 if (N->getOpcode() >= ISD::BUILTIN_OP_END ||
1177 TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode())) {
1179 // Expose the DAG combiner to the target combiner impls.
1180 TargetLowering::DAGCombinerInfo
1181 DagCombineInfo(DAG, !LegalTypes, !LegalOperations, false, this);
1183 RV = TLI.PerformDAGCombine(N, DagCombineInfo);
1187 // If nothing happened still, try promoting the operation.
1188 if (RV.getNode() == 0) {
1189 switch (N->getOpcode()) {
1197 RV = PromoteIntBinOp(SDValue(N, 0));
1202 RV = PromoteIntShiftOp(SDValue(N, 0));
1204 case ISD::SIGN_EXTEND:
1205 case ISD::ZERO_EXTEND:
1206 case ISD::ANY_EXTEND:
1207 RV = PromoteExtend(SDValue(N, 0));
1210 if (PromoteLoad(SDValue(N, 0)))
1216 // If N is a commutative binary node, try commuting it to enable more
1218 if (RV.getNode() == 0 &&
1219 SelectionDAG::isCommutativeBinOp(N->getOpcode()) &&
1220 N->getNumValues() == 1) {
1221 SDValue N0 = N->getOperand(0);
1222 SDValue N1 = N->getOperand(1);
1224 // Constant operands are canonicalized to RHS.
1225 if (isa<ConstantSDNode>(N0) || !isa<ConstantSDNode>(N1)) {
1226 SDValue Ops[] = { N1, N0 };
1227 SDNode *CSENode = DAG.getNodeIfExists(N->getOpcode(), N->getVTList(),
1230 return SDValue(CSENode, 0);
1237 /// getInputChainForNode - Given a node, return its input chain if it has one,
1238 /// otherwise return a null sd operand.
1239 static SDValue getInputChainForNode(SDNode *N) {
1240 if (unsigned NumOps = N->getNumOperands()) {
1241 if (N->getOperand(0).getValueType() == MVT::Other)
1242 return N->getOperand(0);
1243 else if (N->getOperand(NumOps-1).getValueType() == MVT::Other)
1244 return N->getOperand(NumOps-1);
1245 for (unsigned i = 1; i < NumOps-1; ++i)
1246 if (N->getOperand(i).getValueType() == MVT::Other)
1247 return N->getOperand(i);
1252 SDValue DAGCombiner::visitTokenFactor(SDNode *N) {
1253 // If N has two operands, where one has an input chain equal to the other,
1254 // the 'other' chain is redundant.
1255 if (N->getNumOperands() == 2) {
1256 if (getInputChainForNode(N->getOperand(0).getNode()) == N->getOperand(1))
1257 return N->getOperand(0);
1258 if (getInputChainForNode(N->getOperand(1).getNode()) == N->getOperand(0))
1259 return N->getOperand(1);
1262 SmallVector<SDNode *, 8> TFs; // List of token factors to visit.
1263 SmallVector<SDValue, 8> Ops; // Ops for replacing token factor.
1264 SmallPtrSet<SDNode*, 16> SeenOps;
1265 bool Changed = false; // If we should replace this token factor.
1267 // Start out with this token factor.
1270 // Iterate through token factors. The TFs grows when new token factors are
1272 for (unsigned i = 0; i < TFs.size(); ++i) {
1273 SDNode *TF = TFs[i];
1275 // Check each of the operands.
1276 for (unsigned i = 0, ie = TF->getNumOperands(); i != ie; ++i) {
1277 SDValue Op = TF->getOperand(i);
1279 switch (Op.getOpcode()) {
1280 case ISD::EntryToken:
1281 // Entry tokens don't need to be added to the list. They are
1286 case ISD::TokenFactor:
1287 if (Op.hasOneUse() &&
1288 std::find(TFs.begin(), TFs.end(), Op.getNode()) == TFs.end()) {
1289 // Queue up for processing.
1290 TFs.push_back(Op.getNode());
1291 // Clean up in case the token factor is removed.
1292 AddToWorkList(Op.getNode());
1299 // Only add if it isn't already in the list.
1300 if (SeenOps.insert(Op.getNode()))
1311 // If we've change things around then replace token factor.
1314 // The entry token is the only possible outcome.
1315 Result = DAG.getEntryNode();
1317 // New and improved token factor.
1318 Result = DAG.getNode(ISD::TokenFactor, N->getDebugLoc(),
1319 MVT::Other, &Ops[0], Ops.size());
1322 // Don't add users to work list.
1323 return CombineTo(N, Result, false);
1329 /// MERGE_VALUES can always be eliminated.
1330 SDValue DAGCombiner::visitMERGE_VALUES(SDNode *N) {
1331 WorkListRemover DeadNodes(*this);
1332 // Replacing results may cause a different MERGE_VALUES to suddenly
1333 // be CSE'd with N, and carry its uses with it. Iterate until no
1334 // uses remain, to ensure that the node can be safely deleted.
1335 // First add the users of this node to the work list so that they
1336 // can be tried again once they have new operands.
1337 AddUsersToWorkList(N);
1339 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1340 DAG.ReplaceAllUsesOfValueWith(SDValue(N, i), N->getOperand(i));
1341 } while (!N->use_empty());
1342 removeFromWorkList(N);
1344 return SDValue(N, 0); // Return N so it doesn't get rechecked!
1348 SDValue combineShlAddConstant(DebugLoc DL, SDValue N0, SDValue N1,
1349 SelectionDAG &DAG) {
1350 EVT VT = N0.getValueType();
1351 SDValue N00 = N0.getOperand(0);
1352 SDValue N01 = N0.getOperand(1);
1353 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N01);
1355 if (N01C && N00.getOpcode() == ISD::ADD && N00.getNode()->hasOneUse() &&
1356 isa<ConstantSDNode>(N00.getOperand(1))) {
1357 // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
1358 N0 = DAG.getNode(ISD::ADD, N0.getDebugLoc(), VT,
1359 DAG.getNode(ISD::SHL, N00.getDebugLoc(), VT,
1360 N00.getOperand(0), N01),
1361 DAG.getNode(ISD::SHL, N01.getDebugLoc(), VT,
1362 N00.getOperand(1), N01));
1363 return DAG.getNode(ISD::ADD, DL, VT, N0, N1);
1369 SDValue DAGCombiner::visitADD(SDNode *N) {
1370 SDValue N0 = N->getOperand(0);
1371 SDValue N1 = N->getOperand(1);
1372 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1373 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1374 EVT VT = N0.getValueType();
1377 if (VT.isVector()) {
1378 SDValue FoldedVOp = SimplifyVBinOp(N);
1379 if (FoldedVOp.getNode()) return FoldedVOp;
1382 // fold (add x, undef) -> undef
1383 if (N0.getOpcode() == ISD::UNDEF)
1385 if (N1.getOpcode() == ISD::UNDEF)
1387 // fold (add c1, c2) -> c1+c2
1389 return DAG.FoldConstantArithmetic(ISD::ADD, VT, N0C, N1C);
1390 // canonicalize constant to RHS
1392 return DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N1, N0);
1393 // fold (add x, 0) -> x
1394 if (N1C && N1C->isNullValue())
1396 // fold (add Sym, c) -> Sym+c
1397 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1398 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA) && N1C &&
1399 GA->getOpcode() == ISD::GlobalAddress)
1400 return DAG.getGlobalAddress(GA->getGlobal(), N1C->getDebugLoc(), VT,
1402 (uint64_t)N1C->getSExtValue());
1403 // fold ((c1-A)+c2) -> (c1+c2)-A
1404 if (N1C && N0.getOpcode() == ISD::SUB)
1405 if (ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getOperand(0)))
1406 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1407 DAG.getConstant(N1C->getAPIntValue()+
1408 N0C->getAPIntValue(), VT),
1411 SDValue RADD = ReassociateOps(ISD::ADD, N->getDebugLoc(), N0, N1);
1412 if (RADD.getNode() != 0)
1414 // fold ((0-A) + B) -> B-A
1415 if (N0.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N0.getOperand(0)) &&
1416 cast<ConstantSDNode>(N0.getOperand(0))->isNullValue())
1417 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N1, N0.getOperand(1));
1418 // fold (A + (0-B)) -> A-B
1419 if (N1.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N1.getOperand(0)) &&
1420 cast<ConstantSDNode>(N1.getOperand(0))->isNullValue())
1421 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0, N1.getOperand(1));
1422 // fold (A+(B-A)) -> B
1423 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(1))
1424 return N1.getOperand(0);
1425 // fold ((B-A)+A) -> B
1426 if (N0.getOpcode() == ISD::SUB && N1 == N0.getOperand(1))
1427 return N0.getOperand(0);
1428 // fold (A+(B-(A+C))) to (B-C)
1429 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1430 N0 == N1.getOperand(1).getOperand(0))
1431 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N1.getOperand(0),
1432 N1.getOperand(1).getOperand(1));
1433 // fold (A+(B-(C+A))) to (B-C)
1434 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1435 N0 == N1.getOperand(1).getOperand(1))
1436 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N1.getOperand(0),
1437 N1.getOperand(1).getOperand(0));
1438 // fold (A+((B-A)+or-C)) to (B+or-C)
1439 if ((N1.getOpcode() == ISD::SUB || N1.getOpcode() == ISD::ADD) &&
1440 N1.getOperand(0).getOpcode() == ISD::SUB &&
1441 N0 == N1.getOperand(0).getOperand(1))
1442 return DAG.getNode(N1.getOpcode(), N->getDebugLoc(), VT,
1443 N1.getOperand(0).getOperand(0), N1.getOperand(1));
1445 // fold (A-B)+(C-D) to (A+C)-(B+D) when A or C is constant
1446 if (N0.getOpcode() == ISD::SUB && N1.getOpcode() == ISD::SUB) {
1447 SDValue N00 = N0.getOperand(0);
1448 SDValue N01 = N0.getOperand(1);
1449 SDValue N10 = N1.getOperand(0);
1450 SDValue N11 = N1.getOperand(1);
1452 if (isa<ConstantSDNode>(N00) || isa<ConstantSDNode>(N10))
1453 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1454 DAG.getNode(ISD::ADD, N0.getDebugLoc(), VT, N00, N10),
1455 DAG.getNode(ISD::ADD, N1.getDebugLoc(), VT, N01, N11));
1458 if (!VT.isVector() && SimplifyDemandedBits(SDValue(N, 0)))
1459 return SDValue(N, 0);
1461 // fold (a+b) -> (a|b) iff a and b share no bits.
1462 if (VT.isInteger() && !VT.isVector()) {
1463 APInt LHSZero, LHSOne;
1464 APInt RHSZero, RHSOne;
1465 DAG.ComputeMaskedBits(N0, LHSZero, LHSOne);
1467 if (LHSZero.getBoolValue()) {
1468 DAG.ComputeMaskedBits(N1, RHSZero, RHSOne);
1470 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1471 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1472 if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero)
1473 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N1);
1477 // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
1478 if (N0.getOpcode() == ISD::SHL && N0.getNode()->hasOneUse()) {
1479 SDValue Result = combineShlAddConstant(N->getDebugLoc(), N0, N1, DAG);
1480 if (Result.getNode()) return Result;
1482 if (N1.getOpcode() == ISD::SHL && N1.getNode()->hasOneUse()) {
1483 SDValue Result = combineShlAddConstant(N->getDebugLoc(), N1, N0, DAG);
1484 if (Result.getNode()) return Result;
1487 // fold (add x, shl(0 - y, n)) -> sub(x, shl(y, n))
1488 if (N1.getOpcode() == ISD::SHL &&
1489 N1.getOperand(0).getOpcode() == ISD::SUB)
1490 if (ConstantSDNode *C =
1491 dyn_cast<ConstantSDNode>(N1.getOperand(0).getOperand(0)))
1492 if (C->getAPIntValue() == 0)
1493 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0,
1494 DAG.getNode(ISD::SHL, N->getDebugLoc(), VT,
1495 N1.getOperand(0).getOperand(1),
1497 if (N0.getOpcode() == ISD::SHL &&
1498 N0.getOperand(0).getOpcode() == ISD::SUB)
1499 if (ConstantSDNode *C =
1500 dyn_cast<ConstantSDNode>(N0.getOperand(0).getOperand(0)))
1501 if (C->getAPIntValue() == 0)
1502 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N1,
1503 DAG.getNode(ISD::SHL, N->getDebugLoc(), VT,
1504 N0.getOperand(0).getOperand(1),
1507 if (N1.getOpcode() == ISD::AND) {
1508 SDValue AndOp0 = N1.getOperand(0);
1509 ConstantSDNode *AndOp1 = dyn_cast<ConstantSDNode>(N1->getOperand(1));
1510 unsigned NumSignBits = DAG.ComputeNumSignBits(AndOp0);
1511 unsigned DestBits = VT.getScalarType().getSizeInBits();
1513 // (add z, (and (sbbl x, x), 1)) -> (sub z, (sbbl x, x))
1514 // and similar xforms where the inner op is either ~0 or 0.
1515 if (NumSignBits == DestBits && AndOp1 && AndOp1->isOne()) {
1516 DebugLoc DL = N->getDebugLoc();
1517 return DAG.getNode(ISD::SUB, DL, VT, N->getOperand(0), AndOp0);
1521 // add (sext i1), X -> sub X, (zext i1)
1522 if (N0.getOpcode() == ISD::SIGN_EXTEND &&
1523 N0.getOperand(0).getValueType() == MVT::i1 &&
1524 !TLI.isOperationLegal(ISD::SIGN_EXTEND, MVT::i1)) {
1525 DebugLoc DL = N->getDebugLoc();
1526 SDValue ZExt = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0));
1527 return DAG.getNode(ISD::SUB, DL, VT, N1, ZExt);
1533 SDValue DAGCombiner::visitADDC(SDNode *N) {
1534 SDValue N0 = N->getOperand(0);
1535 SDValue N1 = N->getOperand(1);
1536 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1537 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1538 EVT VT = N0.getValueType();
1540 // If the flag result is dead, turn this into an ADD.
1541 if (!N->hasAnyUseOfValue(1))
1542 return CombineTo(N, DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N0, N1),
1543 DAG.getNode(ISD::CARRY_FALSE,
1544 N->getDebugLoc(), MVT::Glue));
1546 // canonicalize constant to RHS.
1548 return DAG.getNode(ISD::ADDC, N->getDebugLoc(), N->getVTList(), N1, N0);
1550 // fold (addc x, 0) -> x + no carry out
1551 if (N1C && N1C->isNullValue())
1552 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE,
1553 N->getDebugLoc(), MVT::Glue));
1555 // fold (addc a, b) -> (or a, b), CARRY_FALSE iff a and b share no bits.
1556 APInt LHSZero, LHSOne;
1557 APInt RHSZero, RHSOne;
1558 DAG.ComputeMaskedBits(N0, LHSZero, LHSOne);
1560 if (LHSZero.getBoolValue()) {
1561 DAG.ComputeMaskedBits(N1, RHSZero, RHSOne);
1563 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1564 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1565 if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero)
1566 return CombineTo(N, DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N1),
1567 DAG.getNode(ISD::CARRY_FALSE,
1568 N->getDebugLoc(), MVT::Glue));
1574 SDValue DAGCombiner::visitADDE(SDNode *N) {
1575 SDValue N0 = N->getOperand(0);
1576 SDValue N1 = N->getOperand(1);
1577 SDValue CarryIn = N->getOperand(2);
1578 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1579 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1581 // canonicalize constant to RHS
1583 return DAG.getNode(ISD::ADDE, N->getDebugLoc(), N->getVTList(),
1586 // fold (adde x, y, false) -> (addc x, y)
1587 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
1588 return DAG.getNode(ISD::ADDC, N->getDebugLoc(), N->getVTList(), N0, N1);
1593 // Since it may not be valid to emit a fold to zero for vector initializers
1594 // check if we can before folding.
1595 static SDValue tryFoldToZero(DebugLoc DL, const TargetLowering &TLI, EVT VT,
1596 SelectionDAG &DAG, bool LegalOperations) {
1597 if (!VT.isVector()) {
1598 return DAG.getConstant(0, VT);
1600 if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)) {
1601 // Produce a vector of zeros.
1602 SDValue El = DAG.getConstant(0, VT.getVectorElementType());
1603 std::vector<SDValue> Ops(VT.getVectorNumElements(), El);
1604 return DAG.getNode(ISD::BUILD_VECTOR, DL, VT,
1605 &Ops[0], Ops.size());
1610 SDValue DAGCombiner::visitSUB(SDNode *N) {
1611 SDValue N0 = N->getOperand(0);
1612 SDValue N1 = N->getOperand(1);
1613 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1614 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1615 ConstantSDNode *N1C1 = N1.getOpcode() != ISD::ADD ? 0 :
1616 dyn_cast<ConstantSDNode>(N1.getOperand(1).getNode());
1617 EVT VT = N0.getValueType();
1620 if (VT.isVector()) {
1621 SDValue FoldedVOp = SimplifyVBinOp(N);
1622 if (FoldedVOp.getNode()) return FoldedVOp;
1625 // fold (sub x, x) -> 0
1626 // FIXME: Refactor this and xor and other similar operations together.
1628 return tryFoldToZero(N->getDebugLoc(), TLI, VT, DAG, LegalOperations);
1629 // fold (sub c1, c2) -> c1-c2
1631 return DAG.FoldConstantArithmetic(ISD::SUB, VT, N0C, N1C);
1632 // fold (sub x, c) -> (add x, -c)
1634 return DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N0,
1635 DAG.getConstant(-N1C->getAPIntValue(), VT));
1636 // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1)
1637 if (N0C && N0C->isAllOnesValue())
1638 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N1, N0);
1639 // fold A-(A-B) -> B
1640 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(0))
1641 return N1.getOperand(1);
1642 // fold (A+B)-A -> B
1643 if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1)
1644 return N0.getOperand(1);
1645 // fold (A+B)-B -> A
1646 if (N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1)
1647 return N0.getOperand(0);
1648 // fold C2-(A+C1) -> (C2-C1)-A
1649 if (N1.getOpcode() == ISD::ADD && N0C && N1C1) {
1650 SDValue NewC = DAG.getConstant(N0C->getAPIntValue() - N1C1->getAPIntValue(),
1652 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, NewC,
1655 // fold ((A+(B+or-C))-B) -> A+or-C
1656 if (N0.getOpcode() == ISD::ADD &&
1657 (N0.getOperand(1).getOpcode() == ISD::SUB ||
1658 N0.getOperand(1).getOpcode() == ISD::ADD) &&
1659 N0.getOperand(1).getOperand(0) == N1)
1660 return DAG.getNode(N0.getOperand(1).getOpcode(), N->getDebugLoc(), VT,
1661 N0.getOperand(0), N0.getOperand(1).getOperand(1));
1662 // fold ((A+(C+B))-B) -> A+C
1663 if (N0.getOpcode() == ISD::ADD &&
1664 N0.getOperand(1).getOpcode() == ISD::ADD &&
1665 N0.getOperand(1).getOperand(1) == N1)
1666 return DAG.getNode(ISD::ADD, N->getDebugLoc(), VT,
1667 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1668 // fold ((A-(B-C))-C) -> A-B
1669 if (N0.getOpcode() == ISD::SUB &&
1670 N0.getOperand(1).getOpcode() == ISD::SUB &&
1671 N0.getOperand(1).getOperand(1) == N1)
1672 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1673 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1675 // If either operand of a sub is undef, the result is undef
1676 if (N0.getOpcode() == ISD::UNDEF)
1678 if (N1.getOpcode() == ISD::UNDEF)
1681 // If the relocation model supports it, consider symbol offsets.
1682 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1683 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA)) {
1684 // fold (sub Sym, c) -> Sym-c
1685 if (N1C && GA->getOpcode() == ISD::GlobalAddress)
1686 return DAG.getGlobalAddress(GA->getGlobal(), N1C->getDebugLoc(), VT,
1688 (uint64_t)N1C->getSExtValue());
1689 // fold (sub Sym+c1, Sym+c2) -> c1-c2
1690 if (GlobalAddressSDNode *GB = dyn_cast<GlobalAddressSDNode>(N1))
1691 if (GA->getGlobal() == GB->getGlobal())
1692 return DAG.getConstant((uint64_t)GA->getOffset() - GB->getOffset(),
1699 SDValue DAGCombiner::visitSUBC(SDNode *N) {
1700 SDValue N0 = N->getOperand(0);
1701 SDValue N1 = N->getOperand(1);
1702 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1703 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1704 EVT VT = N0.getValueType();
1706 // If the flag result is dead, turn this into an SUB.
1707 if (!N->hasAnyUseOfValue(1))
1708 return CombineTo(N, DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0, N1),
1709 DAG.getNode(ISD::CARRY_FALSE, N->getDebugLoc(),
1712 // fold (subc x, x) -> 0 + no borrow
1714 return CombineTo(N, DAG.getConstant(0, VT),
1715 DAG.getNode(ISD::CARRY_FALSE, N->getDebugLoc(),
1718 // fold (subc x, 0) -> x + no borrow
1719 if (N1C && N1C->isNullValue())
1720 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE, N->getDebugLoc(),
1723 // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1) + no borrow
1724 if (N0C && N0C->isAllOnesValue())
1725 return CombineTo(N, DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N1, N0),
1726 DAG.getNode(ISD::CARRY_FALSE, N->getDebugLoc(),
1732 SDValue DAGCombiner::visitSUBE(SDNode *N) {
1733 SDValue N0 = N->getOperand(0);
1734 SDValue N1 = N->getOperand(1);
1735 SDValue CarryIn = N->getOperand(2);
1737 // fold (sube x, y, false) -> (subc x, y)
1738 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
1739 return DAG.getNode(ISD::SUBC, N->getDebugLoc(), N->getVTList(), N0, N1);
1744 SDValue DAGCombiner::visitMUL(SDNode *N) {
1745 SDValue N0 = N->getOperand(0);
1746 SDValue N1 = N->getOperand(1);
1747 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1748 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1749 EVT VT = N0.getValueType();
1752 if (VT.isVector()) {
1753 SDValue FoldedVOp = SimplifyVBinOp(N);
1754 if (FoldedVOp.getNode()) return FoldedVOp;
1757 // fold (mul x, undef) -> 0
1758 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
1759 return DAG.getConstant(0, VT);
1760 // fold (mul c1, c2) -> c1*c2
1762 return DAG.FoldConstantArithmetic(ISD::MUL, VT, N0C, N1C);
1763 // canonicalize constant to RHS
1765 return DAG.getNode(ISD::MUL, N->getDebugLoc(), VT, N1, N0);
1766 // fold (mul x, 0) -> 0
1767 if (N1C && N1C->isNullValue())
1769 // fold (mul x, -1) -> 0-x
1770 if (N1C && N1C->isAllOnesValue())
1771 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1772 DAG.getConstant(0, VT), N0);
1773 // fold (mul x, (1 << c)) -> x << c
1774 if (N1C && N1C->getAPIntValue().isPowerOf2())
1775 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0,
1776 DAG.getConstant(N1C->getAPIntValue().logBase2(),
1777 getShiftAmountTy(N0.getValueType())));
1778 // fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c
1779 if (N1C && (-N1C->getAPIntValue()).isPowerOf2()) {
1780 unsigned Log2Val = (-N1C->getAPIntValue()).logBase2();
1781 // FIXME: If the input is something that is easily negated (e.g. a
1782 // single-use add), we should put the negate there.
1783 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1784 DAG.getConstant(0, VT),
1785 DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0,
1786 DAG.getConstant(Log2Val,
1787 getShiftAmountTy(N0.getValueType()))));
1789 // (mul (shl X, c1), c2) -> (mul X, c2 << c1)
1790 if (N1C && N0.getOpcode() == ISD::SHL &&
1791 isa<ConstantSDNode>(N0.getOperand(1))) {
1792 SDValue C3 = DAG.getNode(ISD::SHL, N->getDebugLoc(), VT,
1793 N1, N0.getOperand(1));
1794 AddToWorkList(C3.getNode());
1795 return DAG.getNode(ISD::MUL, N->getDebugLoc(), VT,
1796 N0.getOperand(0), C3);
1799 // Change (mul (shl X, C), Y) -> (shl (mul X, Y), C) when the shift has one
1802 SDValue Sh(0,0), Y(0,0);
1803 // Check for both (mul (shl X, C), Y) and (mul Y, (shl X, C)).
1804 if (N0.getOpcode() == ISD::SHL && isa<ConstantSDNode>(N0.getOperand(1)) &&
1805 N0.getNode()->hasOneUse()) {
1807 } else if (N1.getOpcode() == ISD::SHL &&
1808 isa<ConstantSDNode>(N1.getOperand(1)) &&
1809 N1.getNode()->hasOneUse()) {
1814 SDValue Mul = DAG.getNode(ISD::MUL, N->getDebugLoc(), VT,
1815 Sh.getOperand(0), Y);
1816 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT,
1817 Mul, Sh.getOperand(1));
1821 // fold (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2)
1822 if (N1C && N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse() &&
1823 isa<ConstantSDNode>(N0.getOperand(1)))
1824 return DAG.getNode(ISD::ADD, N->getDebugLoc(), VT,
1825 DAG.getNode(ISD::MUL, N0.getDebugLoc(), VT,
1826 N0.getOperand(0), N1),
1827 DAG.getNode(ISD::MUL, N1.getDebugLoc(), VT,
1828 N0.getOperand(1), N1));
1831 SDValue RMUL = ReassociateOps(ISD::MUL, N->getDebugLoc(), N0, N1);
1832 if (RMUL.getNode() != 0)
1838 SDValue DAGCombiner::visitSDIV(SDNode *N) {
1839 SDValue N0 = N->getOperand(0);
1840 SDValue N1 = N->getOperand(1);
1841 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1842 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1843 EVT VT = N->getValueType(0);
1846 if (VT.isVector()) {
1847 SDValue FoldedVOp = SimplifyVBinOp(N);
1848 if (FoldedVOp.getNode()) return FoldedVOp;
1851 // fold (sdiv c1, c2) -> c1/c2
1852 if (N0C && N1C && !N1C->isNullValue())
1853 return DAG.FoldConstantArithmetic(ISD::SDIV, VT, N0C, N1C);
1854 // fold (sdiv X, 1) -> X
1855 if (N1C && N1C->getAPIntValue() == 1LL)
1857 // fold (sdiv X, -1) -> 0-X
1858 if (N1C && N1C->isAllOnesValue())
1859 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1860 DAG.getConstant(0, VT), N0);
1861 // If we know the sign bits of both operands are zero, strength reduce to a
1862 // udiv instead. Handles (X&15) /s 4 -> X&15 >> 2
1863 if (!VT.isVector()) {
1864 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
1865 return DAG.getNode(ISD::UDIV, N->getDebugLoc(), N1.getValueType(),
1868 // fold (sdiv X, pow2) -> simple ops after legalize
1869 if (N1C && !N1C->isNullValue() &&
1870 (N1C->getAPIntValue().isPowerOf2() ||
1871 (-N1C->getAPIntValue()).isPowerOf2())) {
1872 // If dividing by powers of two is cheap, then don't perform the following
1874 if (TLI.isPow2DivCheap())
1877 unsigned lg2 = N1C->getAPIntValue().countTrailingZeros();
1879 // Splat the sign bit into the register
1880 SDValue SGN = DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, N0,
1881 DAG.getConstant(VT.getSizeInBits()-1,
1882 getShiftAmountTy(N0.getValueType())));
1883 AddToWorkList(SGN.getNode());
1885 // Add (N0 < 0) ? abs2 - 1 : 0;
1886 SDValue SRL = DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, SGN,
1887 DAG.getConstant(VT.getSizeInBits() - lg2,
1888 getShiftAmountTy(SGN.getValueType())));
1889 SDValue ADD = DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N0, SRL);
1890 AddToWorkList(SRL.getNode());
1891 AddToWorkList(ADD.getNode()); // Divide by pow2
1892 SDValue SRA = DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, ADD,
1893 DAG.getConstant(lg2, getShiftAmountTy(ADD.getValueType())));
1895 // If we're dividing by a positive value, we're done. Otherwise, we must
1896 // negate the result.
1897 if (N1C->getAPIntValue().isNonNegative())
1900 AddToWorkList(SRA.getNode());
1901 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1902 DAG.getConstant(0, VT), SRA);
1905 // if integer divide is expensive and we satisfy the requirements, emit an
1906 // alternate sequence.
1907 if (N1C && !N1C->isNullValue() && !TLI.isIntDivCheap()) {
1908 SDValue Op = BuildSDIV(N);
1909 if (Op.getNode()) return Op;
1913 if (N0.getOpcode() == ISD::UNDEF)
1914 return DAG.getConstant(0, VT);
1915 // X / undef -> undef
1916 if (N1.getOpcode() == ISD::UNDEF)
1922 SDValue DAGCombiner::visitUDIV(SDNode *N) {
1923 SDValue N0 = N->getOperand(0);
1924 SDValue N1 = N->getOperand(1);
1925 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1926 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1927 EVT VT = N->getValueType(0);
1930 if (VT.isVector()) {
1931 SDValue FoldedVOp = SimplifyVBinOp(N);
1932 if (FoldedVOp.getNode()) return FoldedVOp;
1935 // fold (udiv c1, c2) -> c1/c2
1936 if (N0C && N1C && !N1C->isNullValue())
1937 return DAG.FoldConstantArithmetic(ISD::UDIV, VT, N0C, N1C);
1938 // fold (udiv x, (1 << c)) -> x >>u c
1939 if (N1C && N1C->getAPIntValue().isPowerOf2())
1940 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0,
1941 DAG.getConstant(N1C->getAPIntValue().logBase2(),
1942 getShiftAmountTy(N0.getValueType())));
1943 // fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) iff c is power of 2
1944 if (N1.getOpcode() == ISD::SHL) {
1945 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
1946 if (SHC->getAPIntValue().isPowerOf2()) {
1947 EVT ADDVT = N1.getOperand(1).getValueType();
1948 SDValue Add = DAG.getNode(ISD::ADD, N->getDebugLoc(), ADDVT,
1950 DAG.getConstant(SHC->getAPIntValue()
1953 AddToWorkList(Add.getNode());
1954 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0, Add);
1958 // fold (udiv x, c) -> alternate
1959 if (N1C && !N1C->isNullValue() && !TLI.isIntDivCheap()) {
1960 SDValue Op = BuildUDIV(N);
1961 if (Op.getNode()) return Op;
1965 if (N0.getOpcode() == ISD::UNDEF)
1966 return DAG.getConstant(0, VT);
1967 // X / undef -> undef
1968 if (N1.getOpcode() == ISD::UNDEF)
1974 SDValue DAGCombiner::visitSREM(SDNode *N) {
1975 SDValue N0 = N->getOperand(0);
1976 SDValue N1 = N->getOperand(1);
1977 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1978 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1979 EVT VT = N->getValueType(0);
1981 // fold (srem c1, c2) -> c1%c2
1982 if (N0C && N1C && !N1C->isNullValue())
1983 return DAG.FoldConstantArithmetic(ISD::SREM, VT, N0C, N1C);
1984 // If we know the sign bits of both operands are zero, strength reduce to a
1985 // urem instead. Handles (X & 0x0FFFFFFF) %s 16 -> X&15
1986 if (!VT.isVector()) {
1987 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
1988 return DAG.getNode(ISD::UREM, N->getDebugLoc(), VT, N0, N1);
1991 // If X/C can be simplified by the division-by-constant logic, lower
1992 // X%C to the equivalent of X-X/C*C.
1993 if (N1C && !N1C->isNullValue()) {
1994 SDValue Div = DAG.getNode(ISD::SDIV, N->getDebugLoc(), VT, N0, N1);
1995 AddToWorkList(Div.getNode());
1996 SDValue OptimizedDiv = combine(Div.getNode());
1997 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
1998 SDValue Mul = DAG.getNode(ISD::MUL, N->getDebugLoc(), VT,
2000 SDValue Sub = DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0, Mul);
2001 AddToWorkList(Mul.getNode());
2007 if (N0.getOpcode() == ISD::UNDEF)
2008 return DAG.getConstant(0, VT);
2009 // X % undef -> undef
2010 if (N1.getOpcode() == ISD::UNDEF)
2016 SDValue DAGCombiner::visitUREM(SDNode *N) {
2017 SDValue N0 = N->getOperand(0);
2018 SDValue N1 = N->getOperand(1);
2019 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2020 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2021 EVT VT = N->getValueType(0);
2023 // fold (urem c1, c2) -> c1%c2
2024 if (N0C && N1C && !N1C->isNullValue())
2025 return DAG.FoldConstantArithmetic(ISD::UREM, VT, N0C, N1C);
2026 // fold (urem x, pow2) -> (and x, pow2-1)
2027 if (N1C && !N1C->isNullValue() && N1C->getAPIntValue().isPowerOf2())
2028 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0,
2029 DAG.getConstant(N1C->getAPIntValue()-1,VT));
2030 // fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1))
2031 if (N1.getOpcode() == ISD::SHL) {
2032 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
2033 if (SHC->getAPIntValue().isPowerOf2()) {
2035 DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N1,
2036 DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()),
2038 AddToWorkList(Add.getNode());
2039 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0, Add);
2044 // If X/C can be simplified by the division-by-constant logic, lower
2045 // X%C to the equivalent of X-X/C*C.
2046 if (N1C && !N1C->isNullValue()) {
2047 SDValue Div = DAG.getNode(ISD::UDIV, N->getDebugLoc(), VT, N0, N1);
2048 AddToWorkList(Div.getNode());
2049 SDValue OptimizedDiv = combine(Div.getNode());
2050 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
2051 SDValue Mul = DAG.getNode(ISD::MUL, N->getDebugLoc(), VT,
2053 SDValue Sub = DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0, Mul);
2054 AddToWorkList(Mul.getNode());
2060 if (N0.getOpcode() == ISD::UNDEF)
2061 return DAG.getConstant(0, VT);
2062 // X % undef -> undef
2063 if (N1.getOpcode() == ISD::UNDEF)
2069 SDValue DAGCombiner::visitMULHS(SDNode *N) {
2070 SDValue N0 = N->getOperand(0);
2071 SDValue N1 = N->getOperand(1);
2072 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2073 EVT VT = N->getValueType(0);
2074 DebugLoc DL = N->getDebugLoc();
2076 // fold (mulhs x, 0) -> 0
2077 if (N1C && N1C->isNullValue())
2079 // fold (mulhs x, 1) -> (sra x, size(x)-1)
2080 if (N1C && N1C->getAPIntValue() == 1)
2081 return DAG.getNode(ISD::SRA, N->getDebugLoc(), N0.getValueType(), N0,
2082 DAG.getConstant(N0.getValueType().getSizeInBits() - 1,
2083 getShiftAmountTy(N0.getValueType())));
2084 // fold (mulhs x, undef) -> 0
2085 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2086 return DAG.getConstant(0, VT);
2088 // If the type twice as wide is legal, transform the mulhs to a wider multiply
2090 if (VT.isSimple() && !VT.isVector()) {
2091 MVT Simple = VT.getSimpleVT();
2092 unsigned SimpleSize = Simple.getSizeInBits();
2093 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2094 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2095 N0 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N0);
2096 N1 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N1);
2097 N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
2098 N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
2099 DAG.getConstant(SimpleSize, getShiftAmountTy(N1.getValueType())));
2100 return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
2107 SDValue DAGCombiner::visitMULHU(SDNode *N) {
2108 SDValue N0 = N->getOperand(0);
2109 SDValue N1 = N->getOperand(1);
2110 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2111 EVT VT = N->getValueType(0);
2112 DebugLoc DL = N->getDebugLoc();
2114 // fold (mulhu x, 0) -> 0
2115 if (N1C && N1C->isNullValue())
2117 // fold (mulhu x, 1) -> 0
2118 if (N1C && N1C->getAPIntValue() == 1)
2119 return DAG.getConstant(0, N0.getValueType());
2120 // fold (mulhu x, undef) -> 0
2121 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2122 return DAG.getConstant(0, VT);
2124 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2126 if (VT.isSimple() && !VT.isVector()) {
2127 MVT Simple = VT.getSimpleVT();
2128 unsigned SimpleSize = Simple.getSizeInBits();
2129 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2130 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2131 N0 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N0);
2132 N1 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N1);
2133 N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
2134 N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
2135 DAG.getConstant(SimpleSize, getShiftAmountTy(N1.getValueType())));
2136 return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
2143 /// SimplifyNodeWithTwoResults - Perform optimizations common to nodes that
2144 /// compute two values. LoOp and HiOp give the opcodes for the two computations
2145 /// that are being performed. Return true if a simplification was made.
2147 SDValue DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
2149 // If the high half is not needed, just compute the low half.
2150 bool HiExists = N->hasAnyUseOfValue(1);
2152 (!LegalOperations ||
2153 TLI.isOperationLegal(LoOp, N->getValueType(0)))) {
2154 SDValue Res = DAG.getNode(LoOp, N->getDebugLoc(), N->getValueType(0),
2155 N->op_begin(), N->getNumOperands());
2156 return CombineTo(N, Res, Res);
2159 // If the low half is not needed, just compute the high half.
2160 bool LoExists = N->hasAnyUseOfValue(0);
2162 (!LegalOperations ||
2163 TLI.isOperationLegal(HiOp, N->getValueType(1)))) {
2164 SDValue Res = DAG.getNode(HiOp, N->getDebugLoc(), N->getValueType(1),
2165 N->op_begin(), N->getNumOperands());
2166 return CombineTo(N, Res, Res);
2169 // If both halves are used, return as it is.
2170 if (LoExists && HiExists)
2173 // If the two computed results can be simplified separately, separate them.
2175 SDValue Lo = DAG.getNode(LoOp, N->getDebugLoc(), N->getValueType(0),
2176 N->op_begin(), N->getNumOperands());
2177 AddToWorkList(Lo.getNode());
2178 SDValue LoOpt = combine(Lo.getNode());
2179 if (LoOpt.getNode() && LoOpt.getNode() != Lo.getNode() &&
2180 (!LegalOperations ||
2181 TLI.isOperationLegal(LoOpt.getOpcode(), LoOpt.getValueType())))
2182 return CombineTo(N, LoOpt, LoOpt);
2186 SDValue Hi = DAG.getNode(HiOp, N->getDebugLoc(), N->getValueType(1),
2187 N->op_begin(), N->getNumOperands());
2188 AddToWorkList(Hi.getNode());
2189 SDValue HiOpt = combine(Hi.getNode());
2190 if (HiOpt.getNode() && HiOpt != Hi &&
2191 (!LegalOperations ||
2192 TLI.isOperationLegal(HiOpt.getOpcode(), HiOpt.getValueType())))
2193 return CombineTo(N, HiOpt, HiOpt);
2199 SDValue DAGCombiner::visitSMUL_LOHI(SDNode *N) {
2200 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHS);
2201 if (Res.getNode()) return Res;
2203 EVT VT = N->getValueType(0);
2204 DebugLoc DL = N->getDebugLoc();
2206 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2208 if (VT.isSimple() && !VT.isVector()) {
2209 MVT Simple = VT.getSimpleVT();
2210 unsigned SimpleSize = Simple.getSizeInBits();
2211 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2212 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2213 SDValue Lo = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(0));
2214 SDValue Hi = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(1));
2215 Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
2216 // Compute the high part as N1.
2217 Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
2218 DAG.getConstant(SimpleSize, getShiftAmountTy(Lo.getValueType())));
2219 Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
2220 // Compute the low part as N0.
2221 Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
2222 return CombineTo(N, Lo, Hi);
2229 SDValue DAGCombiner::visitUMUL_LOHI(SDNode *N) {
2230 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHU);
2231 if (Res.getNode()) return Res;
2233 EVT VT = N->getValueType(0);
2234 DebugLoc DL = N->getDebugLoc();
2236 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2238 if (VT.isSimple() && !VT.isVector()) {
2239 MVT Simple = VT.getSimpleVT();
2240 unsigned SimpleSize = Simple.getSizeInBits();
2241 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2242 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2243 SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(0));
2244 SDValue Hi = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(1));
2245 Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
2246 // Compute the high part as N1.
2247 Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
2248 DAG.getConstant(SimpleSize, getShiftAmountTy(Lo.getValueType())));
2249 Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
2250 // Compute the low part as N0.
2251 Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
2252 return CombineTo(N, Lo, Hi);
2259 SDValue DAGCombiner::visitSMULO(SDNode *N) {
2260 // (smulo x, 2) -> (saddo x, x)
2261 if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
2262 if (C2->getAPIntValue() == 2)
2263 return DAG.getNode(ISD::SADDO, N->getDebugLoc(), N->getVTList(),
2264 N->getOperand(0), N->getOperand(0));
2269 SDValue DAGCombiner::visitUMULO(SDNode *N) {
2270 // (umulo x, 2) -> (uaddo x, x)
2271 if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
2272 if (C2->getAPIntValue() == 2)
2273 return DAG.getNode(ISD::UADDO, N->getDebugLoc(), N->getVTList(),
2274 N->getOperand(0), N->getOperand(0));
2279 SDValue DAGCombiner::visitSDIVREM(SDNode *N) {
2280 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::SDIV, ISD::SREM);
2281 if (Res.getNode()) return Res;
2286 SDValue DAGCombiner::visitUDIVREM(SDNode *N) {
2287 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::UDIV, ISD::UREM);
2288 if (Res.getNode()) return Res;
2293 /// SimplifyBinOpWithSameOpcodeHands - If this is a binary operator with
2294 /// two operands of the same opcode, try to simplify it.
2295 SDValue DAGCombiner::SimplifyBinOpWithSameOpcodeHands(SDNode *N) {
2296 SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
2297 EVT VT = N0.getValueType();
2298 assert(N0.getOpcode() == N1.getOpcode() && "Bad input!");
2300 // Bail early if none of these transforms apply.
2301 if (N0.getNode()->getNumOperands() == 0) return SDValue();
2303 // For each of OP in AND/OR/XOR:
2304 // fold (OP (zext x), (zext y)) -> (zext (OP x, y))
2305 // fold (OP (sext x), (sext y)) -> (sext (OP x, y))
2306 // fold (OP (aext x), (aext y)) -> (aext (OP x, y))
2307 // fold (OP (trunc x), (trunc y)) -> (trunc (OP x, y)) (if trunc isn't free)
2309 // do not sink logical op inside of a vector extend, since it may combine
2311 EVT Op0VT = N0.getOperand(0).getValueType();
2312 if ((N0.getOpcode() == ISD::ZERO_EXTEND ||
2313 N0.getOpcode() == ISD::SIGN_EXTEND ||
2314 // Avoid infinite looping with PromoteIntBinOp.
2315 (N0.getOpcode() == ISD::ANY_EXTEND &&
2316 (!LegalTypes || TLI.isTypeDesirableForOp(N->getOpcode(), Op0VT))) ||
2317 (N0.getOpcode() == ISD::TRUNCATE &&
2318 (!TLI.isZExtFree(VT, Op0VT) ||
2319 !TLI.isTruncateFree(Op0VT, VT)) &&
2320 TLI.isTypeLegal(Op0VT))) &&
2322 Op0VT == N1.getOperand(0).getValueType() &&
2323 (!LegalOperations || TLI.isOperationLegal(N->getOpcode(), Op0VT))) {
2324 SDValue ORNode = DAG.getNode(N->getOpcode(), N0.getDebugLoc(),
2325 N0.getOperand(0).getValueType(),
2326 N0.getOperand(0), N1.getOperand(0));
2327 AddToWorkList(ORNode.getNode());
2328 return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT, ORNode);
2331 // For each of OP in SHL/SRL/SRA/AND...
2332 // fold (and (OP x, z), (OP y, z)) -> (OP (and x, y), z)
2333 // fold (or (OP x, z), (OP y, z)) -> (OP (or x, y), z)
2334 // fold (xor (OP x, z), (OP y, z)) -> (OP (xor x, y), z)
2335 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL ||
2336 N0.getOpcode() == ISD::SRA || N0.getOpcode() == ISD::AND) &&
2337 N0.getOperand(1) == N1.getOperand(1)) {
2338 SDValue ORNode = DAG.getNode(N->getOpcode(), N0.getDebugLoc(),
2339 N0.getOperand(0).getValueType(),
2340 N0.getOperand(0), N1.getOperand(0));
2341 AddToWorkList(ORNode.getNode());
2342 return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT,
2343 ORNode, N0.getOperand(1));
2346 // Simplify xor/and/or (bitcast(A), bitcast(B)) -> bitcast(op (A,B))
2347 // Only perform this optimization after type legalization and before
2348 // LegalizeVectorOprs. LegalizeVectorOprs promotes vector operations by
2349 // adding bitcasts. For example (xor v4i32) is promoted to (v2i64), and
2350 // we don't want to undo this promotion.
2351 // We also handle SCALAR_TO_VECTOR because xor/or/and operations are cheaper
2353 if ((N0.getOpcode() == ISD::BITCAST ||
2354 N0.getOpcode() == ISD::SCALAR_TO_VECTOR) &&
2355 Level == AfterLegalizeTypes) {
2356 SDValue In0 = N0.getOperand(0);
2357 SDValue In1 = N1.getOperand(0);
2358 EVT In0Ty = In0.getValueType();
2359 EVT In1Ty = In1.getValueType();
2360 DebugLoc DL = N->getDebugLoc();
2361 // If both incoming values are integers, and the original types are the
2363 if (In0Ty.isInteger() && In1Ty.isInteger() && In0Ty == In1Ty) {
2364 SDValue Op = DAG.getNode(N->getOpcode(), DL, In0Ty, In0, In1);
2365 SDValue BC = DAG.getNode(N0.getOpcode(), DL, VT, Op);
2366 AddToWorkList(Op.getNode());
2371 // Xor/and/or are indifferent to the swizzle operation (shuffle of one value).
2372 // Simplify xor/and/or (shuff(A), shuff(B)) -> shuff(op (A,B))
2373 // If both shuffles use the same mask, and both shuffle within a single
2374 // vector, then it is worthwhile to move the swizzle after the operation.
2375 // The type-legalizer generates this pattern when loading illegal
2376 // vector types from memory. In many cases this allows additional shuffle
2378 if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
2379 N0.getOperand(1).getOpcode() == ISD::UNDEF &&
2380 N1.getOperand(1).getOpcode() == ISD::UNDEF) {
2381 ShuffleVectorSDNode *SVN0 = cast<ShuffleVectorSDNode>(N0);
2382 ShuffleVectorSDNode *SVN1 = cast<ShuffleVectorSDNode>(N1);
2384 assert(N0.getOperand(0).getValueType() == N1.getOperand(1).getValueType() &&
2385 "Inputs to shuffles are not the same type");
2387 unsigned NumElts = VT.getVectorNumElements();
2389 // Check that both shuffles use the same mask. The masks are known to be of
2390 // the same length because the result vector type is the same.
2391 bool SameMask = true;
2392 for (unsigned i = 0; i != NumElts; ++i) {
2393 int Idx0 = SVN0->getMaskElt(i);
2394 int Idx1 = SVN1->getMaskElt(i);
2402 SDValue Op = DAG.getNode(N->getOpcode(), N->getDebugLoc(), VT,
2403 N0.getOperand(0), N1.getOperand(0));
2404 AddToWorkList(Op.getNode());
2405 return DAG.getVectorShuffle(VT, N->getDebugLoc(), Op,
2406 DAG.getUNDEF(VT), &SVN0->getMask()[0]);
2413 SDValue DAGCombiner::visitAND(SDNode *N) {
2414 SDValue N0 = N->getOperand(0);
2415 SDValue N1 = N->getOperand(1);
2416 SDValue LL, LR, RL, RR, CC0, CC1;
2417 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2418 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2419 EVT VT = N1.getValueType();
2420 unsigned BitWidth = VT.getScalarType().getSizeInBits();
2423 if (VT.isVector()) {
2424 SDValue FoldedVOp = SimplifyVBinOp(N);
2425 if (FoldedVOp.getNode()) return FoldedVOp;
2428 // fold (and x, undef) -> 0
2429 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2430 return DAG.getConstant(0, VT);
2431 // fold (and c1, c2) -> c1&c2
2433 return DAG.FoldConstantArithmetic(ISD::AND, VT, N0C, N1C);
2434 // canonicalize constant to RHS
2436 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N1, N0);
2437 // fold (and x, -1) -> x
2438 if (N1C && N1C->isAllOnesValue())
2440 // if (and x, c) is known to be zero, return 0
2441 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
2442 APInt::getAllOnesValue(BitWidth)))
2443 return DAG.getConstant(0, VT);
2445 SDValue RAND = ReassociateOps(ISD::AND, N->getDebugLoc(), N0, N1);
2446 if (RAND.getNode() != 0)
2448 // fold (and (or x, C), D) -> D if (C & D) == D
2449 if (N1C && N0.getOpcode() == ISD::OR)
2450 if (ConstantSDNode *ORI = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
2451 if ((ORI->getAPIntValue() & N1C->getAPIntValue()) == N1C->getAPIntValue())
2453 // fold (and (any_ext V), c) -> (zero_ext V) if 'and' only clears top bits.
2454 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
2455 SDValue N0Op0 = N0.getOperand(0);
2456 APInt Mask = ~N1C->getAPIntValue();
2457 Mask = Mask.trunc(N0Op0.getValueSizeInBits());
2458 if (DAG.MaskedValueIsZero(N0Op0, Mask)) {
2459 SDValue Zext = DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(),
2460 N0.getValueType(), N0Op0);
2462 // Replace uses of the AND with uses of the Zero extend node.
2465 // We actually want to replace all uses of the any_extend with the
2466 // zero_extend, to avoid duplicating things. This will later cause this
2467 // AND to be folded.
2468 CombineTo(N0.getNode(), Zext);
2469 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2472 // similarly fold (and (X (load ([non_ext|any_ext|zero_ext] V))), c) ->
2473 // (X (load ([non_ext|zero_ext] V))) if 'and' only clears top bits which must
2474 // already be zero by virtue of the width of the base type of the load.
2476 // the 'X' node here can either be nothing or an extract_vector_elt to catch
2478 if ((N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
2479 N0.getOperand(0).getOpcode() == ISD::LOAD) ||
2480 N0.getOpcode() == ISD::LOAD) {
2481 LoadSDNode *Load = cast<LoadSDNode>( (N0.getOpcode() == ISD::LOAD) ?
2482 N0 : N0.getOperand(0) );
2484 // Get the constant (if applicable) the zero'th operand is being ANDed with.
2485 // This can be a pure constant or a vector splat, in which case we treat the
2486 // vector as a scalar and use the splat value.
2487 APInt Constant = APInt::getNullValue(1);
2488 if (const ConstantSDNode *C = dyn_cast<ConstantSDNode>(N1)) {
2489 Constant = C->getAPIntValue();
2490 } else if (BuildVectorSDNode *Vector = dyn_cast<BuildVectorSDNode>(N1)) {
2491 APInt SplatValue, SplatUndef;
2492 unsigned SplatBitSize;
2494 bool IsSplat = Vector->isConstantSplat(SplatValue, SplatUndef,
2495 SplatBitSize, HasAnyUndefs);
2497 // Undef bits can contribute to a possible optimisation if set, so
2499 SplatValue |= SplatUndef;
2501 // The splat value may be something like "0x00FFFFFF", which means 0 for
2502 // the first vector value and FF for the rest, repeating. We need a mask
2503 // that will apply equally to all members of the vector, so AND all the
2504 // lanes of the constant together.
2505 EVT VT = Vector->getValueType(0);
2506 unsigned BitWidth = VT.getVectorElementType().getSizeInBits();
2508 // If the splat value has been compressed to a bitlength lower
2509 // than the size of the vector lane, we need to re-expand it to
2511 if (BitWidth > SplatBitSize)
2512 for (SplatValue = SplatValue.zextOrTrunc(BitWidth);
2513 SplatBitSize < BitWidth;
2514 SplatBitSize = SplatBitSize * 2)
2515 SplatValue |= SplatValue.shl(SplatBitSize);
2517 Constant = APInt::getAllOnesValue(BitWidth);
2518 for (unsigned i = 0, n = SplatBitSize/BitWidth; i < n; ++i)
2519 Constant &= SplatValue.lshr(i*BitWidth).zextOrTrunc(BitWidth);
2523 // If we want to change an EXTLOAD to a ZEXTLOAD, ensure a ZEXTLOAD is
2524 // actually legal and isn't going to get expanded, else this is a false
2526 bool CanZextLoadProfitably = TLI.isLoadExtLegal(ISD::ZEXTLOAD,
2527 Load->getMemoryVT());
2529 // Resize the constant to the same size as the original memory access before
2530 // extension. If it is still the AllOnesValue then this AND is completely
2533 Constant.zextOrTrunc(Load->getMemoryVT().getScalarType().getSizeInBits());
2536 switch (Load->getExtensionType()) {
2537 default: B = false; break;
2538 case ISD::EXTLOAD: B = CanZextLoadProfitably; break;
2540 case ISD::NON_EXTLOAD: B = true; break;
2543 if (B && Constant.isAllOnesValue()) {
2544 // If the load type was an EXTLOAD, convert to ZEXTLOAD in order to
2545 // preserve semantics once we get rid of the AND.
2546 SDValue NewLoad(Load, 0);
2547 if (Load->getExtensionType() == ISD::EXTLOAD) {
2548 NewLoad = DAG.getLoad(Load->getAddressingMode(), ISD::ZEXTLOAD,
2549 Load->getValueType(0), Load->getDebugLoc(),
2550 Load->getChain(), Load->getBasePtr(),
2551 Load->getOffset(), Load->getMemoryVT(),
2552 Load->getMemOperand());
2553 // Replace uses of the EXTLOAD with the new ZEXTLOAD.
2554 if (Load->getNumValues() == 3) {
2555 // PRE/POST_INC loads have 3 values.
2556 SDValue To[] = { NewLoad.getValue(0), NewLoad.getValue(1),
2557 NewLoad.getValue(2) };
2558 CombineTo(Load, To, 3, true);
2560 CombineTo(Load, NewLoad.getValue(0), NewLoad.getValue(1));
2564 // Fold the AND away, taking care not to fold to the old load node if we
2566 CombineTo(N, (N0.getNode() == Load) ? NewLoad : N0);
2568 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2571 // fold (and (setcc x), (setcc y)) -> (setcc (and x, y))
2572 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
2573 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
2574 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
2576 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
2577 LL.getValueType().isInteger()) {
2578 // fold (and (seteq X, 0), (seteq Y, 0)) -> (seteq (or X, Y), 0)
2579 if (cast<ConstantSDNode>(LR)->isNullValue() && Op1 == ISD::SETEQ) {
2580 SDValue ORNode = DAG.getNode(ISD::OR, N0.getDebugLoc(),
2581 LR.getValueType(), LL, RL);
2582 AddToWorkList(ORNode.getNode());
2583 return DAG.getSetCC(N->getDebugLoc(), VT, ORNode, LR, Op1);
2585 // fold (and (seteq X, -1), (seteq Y, -1)) -> (seteq (and X, Y), -1)
2586 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETEQ) {
2587 SDValue ANDNode = DAG.getNode(ISD::AND, N0.getDebugLoc(),
2588 LR.getValueType(), LL, RL);
2589 AddToWorkList(ANDNode.getNode());
2590 return DAG.getSetCC(N->getDebugLoc(), VT, ANDNode, LR, Op1);
2592 // fold (and (setgt X, -1), (setgt Y, -1)) -> (setgt (or X, Y), -1)
2593 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETGT) {
2594 SDValue ORNode = DAG.getNode(ISD::OR, N0.getDebugLoc(),
2595 LR.getValueType(), LL, RL);
2596 AddToWorkList(ORNode.getNode());
2597 return DAG.getSetCC(N->getDebugLoc(), VT, ORNode, LR, Op1);
2600 // canonicalize equivalent to ll == rl
2601 if (LL == RR && LR == RL) {
2602 Op1 = ISD::getSetCCSwappedOperands(Op1);
2605 if (LL == RL && LR == RR) {
2606 bool isInteger = LL.getValueType().isInteger();
2607 ISD::CondCode Result = ISD::getSetCCAndOperation(Op0, Op1, isInteger);
2608 if (Result != ISD::SETCC_INVALID &&
2609 (!LegalOperations || TLI.isCondCodeLegal(Result, LL.getValueType())))
2610 return DAG.getSetCC(N->getDebugLoc(), N0.getValueType(),
2615 // Simplify: (and (op x...), (op y...)) -> (op (and x, y))
2616 if (N0.getOpcode() == N1.getOpcode()) {
2617 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
2618 if (Tmp.getNode()) return Tmp;
2621 // fold (and (sign_extend_inreg x, i16 to i32), 1) -> (and x, 1)
2622 // fold (and (sra)) -> (and (srl)) when possible.
2623 if (!VT.isVector() &&
2624 SimplifyDemandedBits(SDValue(N, 0)))
2625 return SDValue(N, 0);
2627 // fold (zext_inreg (extload x)) -> (zextload x)
2628 if (ISD::isEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode())) {
2629 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2630 EVT MemVT = LN0->getMemoryVT();
2631 // If we zero all the possible extended bits, then we can turn this into
2632 // a zextload if we are running before legalize or the operation is legal.
2633 unsigned BitWidth = N1.getValueType().getScalarType().getSizeInBits();
2634 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
2635 BitWidth - MemVT.getScalarType().getSizeInBits())) &&
2636 ((!LegalOperations && !LN0->isVolatile()) ||
2637 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT))) {
2638 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, N0.getDebugLoc(), VT,
2639 LN0->getChain(), LN0->getBasePtr(),
2640 LN0->getPointerInfo(), MemVT,
2641 LN0->isVolatile(), LN0->isNonTemporal(),
2642 LN0->getAlignment());
2644 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
2645 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2648 // fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use
2649 if (ISD::isSEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
2651 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2652 EVT MemVT = LN0->getMemoryVT();
2653 // If we zero all the possible extended bits, then we can turn this into
2654 // a zextload if we are running before legalize or the operation is legal.
2655 unsigned BitWidth = N1.getValueType().getScalarType().getSizeInBits();
2656 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
2657 BitWidth - MemVT.getScalarType().getSizeInBits())) &&
2658 ((!LegalOperations && !LN0->isVolatile()) ||
2659 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT))) {
2660 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, N0.getDebugLoc(), VT,
2662 LN0->getBasePtr(), LN0->getPointerInfo(),
2664 LN0->isVolatile(), LN0->isNonTemporal(),
2665 LN0->getAlignment());
2667 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
2668 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2672 // fold (and (load x), 255) -> (zextload x, i8)
2673 // fold (and (extload x, i16), 255) -> (zextload x, i8)
2674 // fold (and (any_ext (extload x, i16)), 255) -> (zextload x, i8)
2675 if (N1C && (N0.getOpcode() == ISD::LOAD ||
2676 (N0.getOpcode() == ISD::ANY_EXTEND &&
2677 N0.getOperand(0).getOpcode() == ISD::LOAD))) {
2678 bool HasAnyExt = N0.getOpcode() == ISD::ANY_EXTEND;
2679 LoadSDNode *LN0 = HasAnyExt
2680 ? cast<LoadSDNode>(N0.getOperand(0))
2681 : cast<LoadSDNode>(N0);
2682 if (LN0->getExtensionType() != ISD::SEXTLOAD &&
2683 LN0->isUnindexed() && N0.hasOneUse() && LN0->hasOneUse()) {
2684 uint32_t ActiveBits = N1C->getAPIntValue().getActiveBits();
2685 if (ActiveBits > 0 && APIntOps::isMask(ActiveBits, N1C->getAPIntValue())){
2686 EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), ActiveBits);
2687 EVT LoadedVT = LN0->getMemoryVT();
2689 if (ExtVT == LoadedVT &&
2690 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, ExtVT))) {
2691 EVT LoadResultTy = HasAnyExt ? LN0->getValueType(0) : VT;
2694 DAG.getExtLoad(ISD::ZEXTLOAD, LN0->getDebugLoc(), LoadResultTy,
2695 LN0->getChain(), LN0->getBasePtr(),
2696 LN0->getPointerInfo(),
2697 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
2698 LN0->getAlignment());
2700 CombineTo(LN0, NewLoad, NewLoad.getValue(1));
2701 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2704 // Do not change the width of a volatile load.
2705 // Do not generate loads of non-round integer types since these can
2706 // be expensive (and would be wrong if the type is not byte sized).
2707 if (!LN0->isVolatile() && LoadedVT.bitsGT(ExtVT) && ExtVT.isRound() &&
2708 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, ExtVT))) {
2709 EVT PtrType = LN0->getOperand(1).getValueType();
2711 unsigned Alignment = LN0->getAlignment();
2712 SDValue NewPtr = LN0->getBasePtr();
2714 // For big endian targets, we need to add an offset to the pointer
2715 // to load the correct bytes. For little endian systems, we merely
2716 // need to read fewer bytes from the same pointer.
2717 if (TLI.isBigEndian()) {
2718 unsigned LVTStoreBytes = LoadedVT.getStoreSize();
2719 unsigned EVTStoreBytes = ExtVT.getStoreSize();
2720 unsigned PtrOff = LVTStoreBytes - EVTStoreBytes;
2721 NewPtr = DAG.getNode(ISD::ADD, LN0->getDebugLoc(), PtrType,
2722 NewPtr, DAG.getConstant(PtrOff, PtrType));
2723 Alignment = MinAlign(Alignment, PtrOff);
2726 AddToWorkList(NewPtr.getNode());
2728 EVT LoadResultTy = HasAnyExt ? LN0->getValueType(0) : VT;
2730 DAG.getExtLoad(ISD::ZEXTLOAD, LN0->getDebugLoc(), LoadResultTy,
2731 LN0->getChain(), NewPtr,
2732 LN0->getPointerInfo(),
2733 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
2736 CombineTo(LN0, Load, Load.getValue(1));
2737 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2743 if (N0.getOpcode() == ISD::ADD && N1.getOpcode() == ISD::SRL &&
2744 VT.getSizeInBits() <= 64) {
2745 if (ConstantSDNode *ADDI = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
2746 APInt ADDC = ADDI->getAPIntValue();
2747 if (!TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
2748 // Look for (and (add x, c1), (lshr y, c2)). If C1 wasn't a legal
2749 // immediate for an add, but it is legal if its top c2 bits are set,
2750 // transform the ADD so the immediate doesn't need to be materialized
2752 if (ConstantSDNode *SRLI = dyn_cast<ConstantSDNode>(N1.getOperand(1))) {
2753 APInt Mask = APInt::getHighBitsSet(VT.getSizeInBits(),
2754 SRLI->getZExtValue());
2755 if (DAG.MaskedValueIsZero(N0.getOperand(1), Mask)) {
2757 if (TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
2759 DAG.getNode(ISD::ADD, N0.getDebugLoc(), VT,
2760 N0.getOperand(0), DAG.getConstant(ADDC, VT));
2761 CombineTo(N0.getNode(), NewAdd);
2762 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2774 /// MatchBSwapHWord - Match (a >> 8) | (a << 8) as (bswap a) >> 16
2776 SDValue DAGCombiner::MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
2777 bool DemandHighBits) {
2778 if (!LegalOperations)
2781 EVT VT = N->getValueType(0);
2782 if (VT != MVT::i64 && VT != MVT::i32 && VT != MVT::i16)
2784 if (!TLI.isOperationLegal(ISD::BSWAP, VT))
2787 // Recognize (and (shl a, 8), 0xff), (and (srl a, 8), 0xff00)
2788 bool LookPassAnd0 = false;
2789 bool LookPassAnd1 = false;
2790 if (N0.getOpcode() == ISD::AND && N0.getOperand(0).getOpcode() == ISD::SRL)
2792 if (N1.getOpcode() == ISD::AND && N1.getOperand(0).getOpcode() == ISD::SHL)
2794 if (N0.getOpcode() == ISD::AND) {
2795 if (!N0.getNode()->hasOneUse())
2797 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2798 if (!N01C || N01C->getZExtValue() != 0xFF00)
2800 N0 = N0.getOperand(0);
2801 LookPassAnd0 = true;
2804 if (N1.getOpcode() == ISD::AND) {
2805 if (!N1.getNode()->hasOneUse())
2807 ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
2808 if (!N11C || N11C->getZExtValue() != 0xFF)
2810 N1 = N1.getOperand(0);
2811 LookPassAnd1 = true;
2814 if (N0.getOpcode() == ISD::SRL && N1.getOpcode() == ISD::SHL)
2816 if (N0.getOpcode() != ISD::SHL || N1.getOpcode() != ISD::SRL)
2818 if (!N0.getNode()->hasOneUse() ||
2819 !N1.getNode()->hasOneUse())
2822 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2823 ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
2826 if (N01C->getZExtValue() != 8 || N11C->getZExtValue() != 8)
2829 // Look for (shl (and a, 0xff), 8), (srl (and a, 0xff00), 8)
2830 SDValue N00 = N0->getOperand(0);
2831 if (!LookPassAnd0 && N00.getOpcode() == ISD::AND) {
2832 if (!N00.getNode()->hasOneUse())
2834 ConstantSDNode *N001C = dyn_cast<ConstantSDNode>(N00.getOperand(1));
2835 if (!N001C || N001C->getZExtValue() != 0xFF)
2837 N00 = N00.getOperand(0);
2838 LookPassAnd0 = true;
2841 SDValue N10 = N1->getOperand(0);
2842 if (!LookPassAnd1 && N10.getOpcode() == ISD::AND) {
2843 if (!N10.getNode()->hasOneUse())
2845 ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N10.getOperand(1));
2846 if (!N101C || N101C->getZExtValue() != 0xFF00)
2848 N10 = N10.getOperand(0);
2849 LookPassAnd1 = true;
2855 // Make sure everything beyond the low halfword is zero since the SRL 16
2856 // will clear the top bits.
2857 unsigned OpSizeInBits = VT.getSizeInBits();
2858 if (DemandHighBits && OpSizeInBits > 16 &&
2859 (!LookPassAnd0 || !LookPassAnd1) &&
2860 !DAG.MaskedValueIsZero(N10, APInt::getHighBitsSet(OpSizeInBits, 16)))
2863 SDValue Res = DAG.getNode(ISD::BSWAP, N->getDebugLoc(), VT, N00);
2864 if (OpSizeInBits > 16)
2865 Res = DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, Res,
2866 DAG.getConstant(OpSizeInBits-16, getShiftAmountTy(VT)));
2870 /// isBSwapHWordElement - Return true if the specified node is an element
2871 /// that makes up a 32-bit packed halfword byteswap. i.e.
2872 /// ((x&0xff)<<8)|((x&0xff00)>>8)|((x&0x00ff0000)<<8)|((x&0xff000000)>>8)
2873 static bool isBSwapHWordElement(SDValue N, SmallVector<SDNode*,4> &Parts) {
2874 if (!N.getNode()->hasOneUse())
2877 unsigned Opc = N.getOpcode();
2878 if (Opc != ISD::AND && Opc != ISD::SHL && Opc != ISD::SRL)
2881 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N.getOperand(1));
2886 switch (N1C->getZExtValue()) {
2889 case 0xFF: Num = 0; break;
2890 case 0xFF00: Num = 1; break;
2891 case 0xFF0000: Num = 2; break;
2892 case 0xFF000000: Num = 3; break;
2895 // Look for (x & 0xff) << 8 as well as ((x << 8) & 0xff00).
2896 SDValue N0 = N.getOperand(0);
2897 if (Opc == ISD::AND) {
2898 if (Num == 0 || Num == 2) {
2900 // (x >> 8) & 0xff0000
2901 if (N0.getOpcode() != ISD::SRL)
2903 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2904 if (!C || C->getZExtValue() != 8)
2907 // (x << 8) & 0xff00
2908 // (x << 8) & 0xff000000
2909 if (N0.getOpcode() != ISD::SHL)
2911 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2912 if (!C || C->getZExtValue() != 8)
2915 } else if (Opc == ISD::SHL) {
2917 // (x & 0xff0000) << 8
2918 if (Num != 0 && Num != 2)
2920 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
2921 if (!C || C->getZExtValue() != 8)
2923 } else { // Opc == ISD::SRL
2924 // (x & 0xff00) >> 8
2925 // (x & 0xff000000) >> 8
2926 if (Num != 1 && Num != 3)
2928 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
2929 if (!C || C->getZExtValue() != 8)
2936 Parts[Num] = N0.getOperand(0).getNode();
2940 /// MatchBSwapHWord - Match a 32-bit packed halfword bswap. That is
2941 /// ((x&0xff)<<8)|((x&0xff00)>>8)|((x&0x00ff0000)<<8)|((x&0xff000000)>>8)
2942 /// => (rotl (bswap x), 16)
2943 SDValue DAGCombiner::MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1) {
2944 if (!LegalOperations)
2947 EVT VT = N->getValueType(0);
2950 if (!TLI.isOperationLegal(ISD::BSWAP, VT))
2953 SmallVector<SDNode*,4> Parts(4, (SDNode*)0);
2955 // (or (or (and), (and)), (or (and), (and)))
2956 // (or (or (or (and), (and)), (and)), (and))
2957 if (N0.getOpcode() != ISD::OR)
2959 SDValue N00 = N0.getOperand(0);
2960 SDValue N01 = N0.getOperand(1);
2962 if (N1.getOpcode() == ISD::OR) {
2963 // (or (or (and), (and)), (or (and), (and)))
2964 SDValue N000 = N00.getOperand(0);
2965 if (!isBSwapHWordElement(N000, Parts))
2968 SDValue N001 = N00.getOperand(1);
2969 if (!isBSwapHWordElement(N001, Parts))
2971 SDValue N010 = N01.getOperand(0);
2972 if (!isBSwapHWordElement(N010, Parts))
2974 SDValue N011 = N01.getOperand(1);
2975 if (!isBSwapHWordElement(N011, Parts))
2978 // (or (or (or (and), (and)), (and)), (and))
2979 if (!isBSwapHWordElement(N1, Parts))
2981 if (!isBSwapHWordElement(N01, Parts))
2983 if (N00.getOpcode() != ISD::OR)
2985 SDValue N000 = N00.getOperand(0);
2986 if (!isBSwapHWordElement(N000, Parts))
2988 SDValue N001 = N00.getOperand(1);
2989 if (!isBSwapHWordElement(N001, Parts))
2993 // Make sure the parts are all coming from the same node.
2994 if (Parts[0] != Parts[1] || Parts[0] != Parts[2] || Parts[0] != Parts[3])
2997 SDValue BSwap = DAG.getNode(ISD::BSWAP, N->getDebugLoc(), VT,
2998 SDValue(Parts[0],0));
3000 // Result of the bswap should be rotated by 16. If it's not legal, than
3001 // do (x << 16) | (x >> 16).
3002 SDValue ShAmt = DAG.getConstant(16, getShiftAmountTy(VT));
3003 if (TLI.isOperationLegalOrCustom(ISD::ROTL, VT))
3004 return DAG.getNode(ISD::ROTL, N->getDebugLoc(), VT, BSwap, ShAmt);
3005 if (TLI.isOperationLegalOrCustom(ISD::ROTR, VT))
3006 return DAG.getNode(ISD::ROTR, N->getDebugLoc(), VT, BSwap, ShAmt);
3007 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT,
3008 DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, BSwap, ShAmt),
3009 DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, BSwap, ShAmt));
3012 SDValue DAGCombiner::visitOR(SDNode *N) {
3013 SDValue N0 = N->getOperand(0);
3014 SDValue N1 = N->getOperand(1);
3015 SDValue LL, LR, RL, RR, CC0, CC1;
3016 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3017 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3018 EVT VT = N1.getValueType();
3021 if (VT.isVector()) {
3022 SDValue FoldedVOp = SimplifyVBinOp(N);
3023 if (FoldedVOp.getNode()) return FoldedVOp;
3026 // fold (or x, undef) -> -1
3027 if (!LegalOperations &&
3028 (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)) {
3029 EVT EltVT = VT.isVector() ? VT.getVectorElementType() : VT;
3030 return DAG.getConstant(APInt::getAllOnesValue(EltVT.getSizeInBits()), VT);
3032 // fold (or c1, c2) -> c1|c2
3034 return DAG.FoldConstantArithmetic(ISD::OR, VT, N0C, N1C);
3035 // canonicalize constant to RHS
3037 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N1, N0);
3038 // fold (or x, 0) -> x
3039 if (N1C && N1C->isNullValue())
3041 // fold (or x, -1) -> -1
3042 if (N1C && N1C->isAllOnesValue())
3044 // fold (or x, c) -> c iff (x & ~c) == 0
3045 if (N1C && DAG.MaskedValueIsZero(N0, ~N1C->getAPIntValue()))
3048 // Recognize halfword bswaps as (bswap + rotl 16) or (bswap + shl 16)
3049 SDValue BSwap = MatchBSwapHWord(N, N0, N1);
3050 if (BSwap.getNode() != 0)
3052 BSwap = MatchBSwapHWordLow(N, N0, N1);
3053 if (BSwap.getNode() != 0)
3057 SDValue ROR = ReassociateOps(ISD::OR, N->getDebugLoc(), N0, N1);
3058 if (ROR.getNode() != 0)
3060 // Canonicalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2)
3061 // iff (c1 & c2) == 0.
3062 if (N1C && N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
3063 isa<ConstantSDNode>(N0.getOperand(1))) {
3064 ConstantSDNode *C1 = cast<ConstantSDNode>(N0.getOperand(1));
3065 if ((C1->getAPIntValue() & N1C->getAPIntValue()) != 0)
3066 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
3067 DAG.getNode(ISD::OR, N0.getDebugLoc(), VT,
3068 N0.getOperand(0), N1),
3069 DAG.FoldConstantArithmetic(ISD::OR, VT, N1C, C1));
3071 // fold (or (setcc x), (setcc y)) -> (setcc (or x, y))
3072 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
3073 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
3074 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
3076 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
3077 LL.getValueType().isInteger()) {
3078 // fold (or (setne X, 0), (setne Y, 0)) -> (setne (or X, Y), 0)
3079 // fold (or (setlt X, 0), (setlt Y, 0)) -> (setne (or X, Y), 0)
3080 if (cast<ConstantSDNode>(LR)->isNullValue() &&
3081 (Op1 == ISD::SETNE || Op1 == ISD::SETLT)) {
3082 SDValue ORNode = DAG.getNode(ISD::OR, LR.getDebugLoc(),
3083 LR.getValueType(), LL, RL);
3084 AddToWorkList(ORNode.getNode());
3085 return DAG.getSetCC(N->getDebugLoc(), VT, ORNode, LR, Op1);
3087 // fold (or (setne X, -1), (setne Y, -1)) -> (setne (and X, Y), -1)
3088 // fold (or (setgt X, -1), (setgt Y -1)) -> (setgt (and X, Y), -1)
3089 if (cast<ConstantSDNode>(LR)->isAllOnesValue() &&
3090 (Op1 == ISD::SETNE || Op1 == ISD::SETGT)) {
3091 SDValue ANDNode = DAG.getNode(ISD::AND, LR.getDebugLoc(),
3092 LR.getValueType(), LL, RL);
3093 AddToWorkList(ANDNode.getNode());
3094 return DAG.getSetCC(N->getDebugLoc(), VT, ANDNode, LR, Op1);
3097 // canonicalize equivalent to ll == rl
3098 if (LL == RR && LR == RL) {
3099 Op1 = ISD::getSetCCSwappedOperands(Op1);
3102 if (LL == RL && LR == RR) {
3103 bool isInteger = LL.getValueType().isInteger();
3104 ISD::CondCode Result = ISD::getSetCCOrOperation(Op0, Op1, isInteger);
3105 if (Result != ISD::SETCC_INVALID &&
3106 (!LegalOperations || TLI.isCondCodeLegal(Result, LL.getValueType())))
3107 return DAG.getSetCC(N->getDebugLoc(), N0.getValueType(),
3112 // Simplify: (or (op x...), (op y...)) -> (op (or x, y))
3113 if (N0.getOpcode() == N1.getOpcode()) {
3114 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
3115 if (Tmp.getNode()) return Tmp;
3118 // (or (and X, C1), (and Y, C2)) -> (and (or X, Y), C3) if possible.
3119 if (N0.getOpcode() == ISD::AND &&
3120 N1.getOpcode() == ISD::AND &&
3121 N0.getOperand(1).getOpcode() == ISD::Constant &&
3122 N1.getOperand(1).getOpcode() == ISD::Constant &&
3123 // Don't increase # computations.
3124 (N0.getNode()->hasOneUse() || N1.getNode()->hasOneUse())) {
3125 // We can only do this xform if we know that bits from X that are set in C2
3126 // but not in C1 are already zero. Likewise for Y.
3127 const APInt &LHSMask =
3128 cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
3129 const APInt &RHSMask =
3130 cast<ConstantSDNode>(N1.getOperand(1))->getAPIntValue();
3132 if (DAG.MaskedValueIsZero(N0.getOperand(0), RHSMask&~LHSMask) &&
3133 DAG.MaskedValueIsZero(N1.getOperand(0), LHSMask&~RHSMask)) {
3134 SDValue X = DAG.getNode(ISD::OR, N0.getDebugLoc(), VT,
3135 N0.getOperand(0), N1.getOperand(0));
3136 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, X,
3137 DAG.getConstant(LHSMask | RHSMask, VT));
3141 // See if this is some rotate idiom.
3142 if (SDNode *Rot = MatchRotate(N0, N1, N->getDebugLoc()))
3143 return SDValue(Rot, 0);
3145 // Simplify the operands using demanded-bits information.
3146 if (!VT.isVector() &&
3147 SimplifyDemandedBits(SDValue(N, 0)))
3148 return SDValue(N, 0);
3153 /// MatchRotateHalf - Match "(X shl/srl V1) & V2" where V2 may not be present.
3154 static bool MatchRotateHalf(SDValue Op, SDValue &Shift, SDValue &Mask) {
3155 if (Op.getOpcode() == ISD::AND) {
3156 if (isa<ConstantSDNode>(Op.getOperand(1))) {
3157 Mask = Op.getOperand(1);
3158 Op = Op.getOperand(0);
3164 if (Op.getOpcode() == ISD::SRL || Op.getOpcode() == ISD::SHL) {
3172 // MatchRotate - Handle an 'or' of two operands. If this is one of the many
3173 // idioms for rotate, and if the target supports rotation instructions, generate
3175 SDNode *DAGCombiner::MatchRotate(SDValue LHS, SDValue RHS, DebugLoc DL) {
3176 // Must be a legal type. Expanded 'n promoted things won't work with rotates.
3177 EVT VT = LHS.getValueType();
3178 if (!TLI.isTypeLegal(VT)) return 0;
3180 // The target must have at least one rotate flavor.
3181 bool HasROTL = TLI.isOperationLegalOrCustom(ISD::ROTL, VT);
3182 bool HasROTR = TLI.isOperationLegalOrCustom(ISD::ROTR, VT);
3183 if (!HasROTL && !HasROTR) return 0;
3185 // Match "(X shl/srl V1) & V2" where V2 may not be present.
3186 SDValue LHSShift; // The shift.
3187 SDValue LHSMask; // AND value if any.
3188 if (!MatchRotateHalf(LHS, LHSShift, LHSMask))
3189 return 0; // Not part of a rotate.
3191 SDValue RHSShift; // The shift.
3192 SDValue RHSMask; // AND value if any.
3193 if (!MatchRotateHalf(RHS, RHSShift, RHSMask))
3194 return 0; // Not part of a rotate.
3196 if (LHSShift.getOperand(0) != RHSShift.getOperand(0))
3197 return 0; // Not shifting the same value.
3199 if (LHSShift.getOpcode() == RHSShift.getOpcode())
3200 return 0; // Shifts must disagree.
3202 // Canonicalize shl to left side in a shl/srl pair.
3203 if (RHSShift.getOpcode() == ISD::SHL) {
3204 std::swap(LHS, RHS);
3205 std::swap(LHSShift, RHSShift);
3206 std::swap(LHSMask , RHSMask );
3209 unsigned OpSizeInBits = VT.getSizeInBits();
3210 SDValue LHSShiftArg = LHSShift.getOperand(0);
3211 SDValue LHSShiftAmt = LHSShift.getOperand(1);
3212 SDValue RHSShiftAmt = RHSShift.getOperand(1);
3214 // fold (or (shl x, C1), (srl x, C2)) -> (rotl x, C1)
3215 // fold (or (shl x, C1), (srl x, C2)) -> (rotr x, C2)
3216 if (LHSShiftAmt.getOpcode() == ISD::Constant &&
3217 RHSShiftAmt.getOpcode() == ISD::Constant) {
3218 uint64_t LShVal = cast<ConstantSDNode>(LHSShiftAmt)->getZExtValue();
3219 uint64_t RShVal = cast<ConstantSDNode>(RHSShiftAmt)->getZExtValue();
3220 if ((LShVal + RShVal) != OpSizeInBits)
3223 SDValue Rot = DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT,
3224 LHSShiftArg, HasROTL ? LHSShiftAmt : RHSShiftAmt);
3226 // If there is an AND of either shifted operand, apply it to the result.
3227 if (LHSMask.getNode() || RHSMask.getNode()) {
3228 APInt Mask = APInt::getAllOnesValue(OpSizeInBits);
3230 if (LHSMask.getNode()) {
3231 APInt RHSBits = APInt::getLowBitsSet(OpSizeInBits, LShVal);
3232 Mask &= cast<ConstantSDNode>(LHSMask)->getAPIntValue() | RHSBits;
3234 if (RHSMask.getNode()) {
3235 APInt LHSBits = APInt::getHighBitsSet(OpSizeInBits, RShVal);
3236 Mask &= cast<ConstantSDNode>(RHSMask)->getAPIntValue() | LHSBits;
3239 Rot = DAG.getNode(ISD::AND, DL, VT, Rot, DAG.getConstant(Mask, VT));
3242 return Rot.getNode();
3245 // If there is a mask here, and we have a variable shift, we can't be sure
3246 // that we're masking out the right stuff.
3247 if (LHSMask.getNode() || RHSMask.getNode())
3250 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotl x, y)
3251 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotr x, (sub 32, y))
3252 if (RHSShiftAmt.getOpcode() == ISD::SUB &&
3253 LHSShiftAmt == RHSShiftAmt.getOperand(1)) {
3254 if (ConstantSDNode *SUBC =
3255 dyn_cast<ConstantSDNode>(RHSShiftAmt.getOperand(0))) {
3256 if (SUBC->getAPIntValue() == OpSizeInBits) {
3257 return DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT, LHSShiftArg,
3258 HasROTL ? LHSShiftAmt : RHSShiftAmt).getNode();
3263 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotr x, y)
3264 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotl x, (sub 32, y))
3265 if (LHSShiftAmt.getOpcode() == ISD::SUB &&
3266 RHSShiftAmt == LHSShiftAmt.getOperand(1)) {
3267 if (ConstantSDNode *SUBC =
3268 dyn_cast<ConstantSDNode>(LHSShiftAmt.getOperand(0))) {
3269 if (SUBC->getAPIntValue() == OpSizeInBits) {
3270 return DAG.getNode(HasROTR ? ISD::ROTR : ISD::ROTL, DL, VT, LHSShiftArg,
3271 HasROTR ? RHSShiftAmt : LHSShiftAmt).getNode();
3276 // Look for sign/zext/any-extended or truncate cases:
3277 if ((LHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
3278 LHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
3279 LHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
3280 LHSShiftAmt.getOpcode() == ISD::TRUNCATE) &&
3281 (RHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
3282 RHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
3283 RHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
3284 RHSShiftAmt.getOpcode() == ISD::TRUNCATE)) {
3285 SDValue LExtOp0 = LHSShiftAmt.getOperand(0);
3286 SDValue RExtOp0 = RHSShiftAmt.getOperand(0);
3287 if (RExtOp0.getOpcode() == ISD::SUB &&
3288 RExtOp0.getOperand(1) == LExtOp0) {
3289 // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
3291 // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
3292 // (rotr x, (sub 32, y))
3293 if (ConstantSDNode *SUBC =
3294 dyn_cast<ConstantSDNode>(RExtOp0.getOperand(0))) {
3295 if (SUBC->getAPIntValue() == OpSizeInBits) {
3296 return DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT,
3298 HasROTL ? LHSShiftAmt : RHSShiftAmt).getNode();
3301 } else if (LExtOp0.getOpcode() == ISD::SUB &&
3302 RExtOp0 == LExtOp0.getOperand(1)) {
3303 // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext y))) ->
3305 // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext y))) ->
3306 // (rotl x, (sub 32, y))
3307 if (ConstantSDNode *SUBC =
3308 dyn_cast<ConstantSDNode>(LExtOp0.getOperand(0))) {
3309 if (SUBC->getAPIntValue() == OpSizeInBits) {
3310 return DAG.getNode(HasROTR ? ISD::ROTR : ISD::ROTL, DL, VT,
3312 HasROTR ? RHSShiftAmt : LHSShiftAmt).getNode();
3321 SDValue DAGCombiner::visitXOR(SDNode *N) {
3322 SDValue N0 = N->getOperand(0);
3323 SDValue N1 = N->getOperand(1);
3324 SDValue LHS, RHS, CC;
3325 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3326 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3327 EVT VT = N0.getValueType();
3330 if (VT.isVector()) {
3331 SDValue FoldedVOp = SimplifyVBinOp(N);
3332 if (FoldedVOp.getNode()) return FoldedVOp;
3335 // fold (xor undef, undef) -> 0. This is a common idiom (misuse).
3336 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
3337 return DAG.getConstant(0, VT);
3338 // fold (xor x, undef) -> undef
3339 if (N0.getOpcode() == ISD::UNDEF)
3341 if (N1.getOpcode() == ISD::UNDEF)
3343 // fold (xor c1, c2) -> c1^c2
3345 return DAG.FoldConstantArithmetic(ISD::XOR, VT, N0C, N1C);
3346 // canonicalize constant to RHS
3348 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N1, N0);
3349 // fold (xor x, 0) -> x
3350 if (N1C && N1C->isNullValue())
3353 SDValue RXOR = ReassociateOps(ISD::XOR, N->getDebugLoc(), N0, N1);
3354 if (RXOR.getNode() != 0)
3357 // fold !(x cc y) -> (x !cc y)
3358 if (N1C && N1C->getAPIntValue() == 1 && isSetCCEquivalent(N0, LHS, RHS, CC)) {
3359 bool isInt = LHS.getValueType().isInteger();
3360 ISD::CondCode NotCC = ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
3363 if (!LegalOperations || TLI.isCondCodeLegal(NotCC, LHS.getValueType())) {
3364 switch (N0.getOpcode()) {
3366 llvm_unreachable("Unhandled SetCC Equivalent!");
3368 return DAG.getSetCC(N->getDebugLoc(), VT, LHS, RHS, NotCC);
3369 case ISD::SELECT_CC:
3370 return DAG.getSelectCC(N->getDebugLoc(), LHS, RHS, N0.getOperand(2),
3371 N0.getOperand(3), NotCC);
3376 // fold (not (zext (setcc x, y))) -> (zext (not (setcc x, y)))
3377 if (N1C && N1C->getAPIntValue() == 1 && N0.getOpcode() == ISD::ZERO_EXTEND &&
3378 N0.getNode()->hasOneUse() &&
3379 isSetCCEquivalent(N0.getOperand(0), LHS, RHS, CC)){
3380 SDValue V = N0.getOperand(0);
3381 V = DAG.getNode(ISD::XOR, N0.getDebugLoc(), V.getValueType(), V,
3382 DAG.getConstant(1, V.getValueType()));
3383 AddToWorkList(V.getNode());
3384 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, V);
3387 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are setcc
3388 if (N1C && N1C->getAPIntValue() == 1 && VT == MVT::i1 &&
3389 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
3390 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
3391 if (isOneUseSetCC(RHS) || isOneUseSetCC(LHS)) {
3392 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
3393 LHS = DAG.getNode(ISD::XOR, LHS.getDebugLoc(), VT, LHS, N1); // LHS = ~LHS
3394 RHS = DAG.getNode(ISD::XOR, RHS.getDebugLoc(), VT, RHS, N1); // RHS = ~RHS
3395 AddToWorkList(LHS.getNode()); AddToWorkList(RHS.getNode());
3396 return DAG.getNode(NewOpcode, N->getDebugLoc(), VT, LHS, RHS);
3399 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are constants
3400 if (N1C && N1C->isAllOnesValue() &&
3401 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
3402 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
3403 if (isa<ConstantSDNode>(RHS) || isa<ConstantSDNode>(LHS)) {
3404 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
3405 LHS = DAG.getNode(ISD::XOR, LHS.getDebugLoc(), VT, LHS, N1); // LHS = ~LHS
3406 RHS = DAG.getNode(ISD::XOR, RHS.getDebugLoc(), VT, RHS, N1); // RHS = ~RHS
3407 AddToWorkList(LHS.getNode()); AddToWorkList(RHS.getNode());
3408 return DAG.getNode(NewOpcode, N->getDebugLoc(), VT, LHS, RHS);
3411 // fold (xor (xor x, c1), c2) -> (xor x, (xor c1, c2))
3412 if (N1C && N0.getOpcode() == ISD::XOR) {
3413 ConstantSDNode *N00C = dyn_cast<ConstantSDNode>(N0.getOperand(0));
3414 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3416 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N0.getOperand(1),
3417 DAG.getConstant(N1C->getAPIntValue() ^
3418 N00C->getAPIntValue(), VT));
3420 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N0.getOperand(0),
3421 DAG.getConstant(N1C->getAPIntValue() ^
3422 N01C->getAPIntValue(), VT));
3424 // fold (xor x, x) -> 0
3426 return tryFoldToZero(N->getDebugLoc(), TLI, VT, DAG, LegalOperations);
3428 // Simplify: xor (op x...), (op y...) -> (op (xor x, y))
3429 if (N0.getOpcode() == N1.getOpcode()) {
3430 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
3431 if (Tmp.getNode()) return Tmp;
3434 // Simplify the expression using non-local knowledge.
3435 if (!VT.isVector() &&
3436 SimplifyDemandedBits(SDValue(N, 0)))
3437 return SDValue(N, 0);
3442 /// visitShiftByConstant - Handle transforms common to the three shifts, when
3443 /// the shift amount is a constant.
3444 SDValue DAGCombiner::visitShiftByConstant(SDNode *N, unsigned Amt) {
3445 SDNode *LHS = N->getOperand(0).getNode();
3446 if (!LHS->hasOneUse()) return SDValue();
3448 // We want to pull some binops through shifts, so that we have (and (shift))
3449 // instead of (shift (and)), likewise for add, or, xor, etc. This sort of
3450 // thing happens with address calculations, so it's important to canonicalize
3452 bool HighBitSet = false; // Can we transform this if the high bit is set?
3454 switch (LHS->getOpcode()) {
3455 default: return SDValue();
3458 HighBitSet = false; // We can only transform sra if the high bit is clear.
3461 HighBitSet = true; // We can only transform sra if the high bit is set.
3464 if (N->getOpcode() != ISD::SHL)
3465 return SDValue(); // only shl(add) not sr[al](add).
3466 HighBitSet = false; // We can only transform sra if the high bit is clear.
3470 // We require the RHS of the binop to be a constant as well.
3471 ConstantSDNode *BinOpCst = dyn_cast<ConstantSDNode>(LHS->getOperand(1));
3472 if (!BinOpCst) return SDValue();
3474 // FIXME: disable this unless the input to the binop is a shift by a constant.
3475 // If it is not a shift, it pessimizes some common cases like:
3477 // void foo(int *X, int i) { X[i & 1235] = 1; }
3478 // int bar(int *X, int i) { return X[i & 255]; }
3479 SDNode *BinOpLHSVal = LHS->getOperand(0).getNode();
3480 if ((BinOpLHSVal->getOpcode() != ISD::SHL &&
3481 BinOpLHSVal->getOpcode() != ISD::SRA &&
3482 BinOpLHSVal->getOpcode() != ISD::SRL) ||
3483 !isa<ConstantSDNode>(BinOpLHSVal->getOperand(1)))
3486 EVT VT = N->getValueType(0);
3488 // If this is a signed shift right, and the high bit is modified by the
3489 // logical operation, do not perform the transformation. The highBitSet
3490 // boolean indicates the value of the high bit of the constant which would
3491 // cause it to be modified for this operation.
3492 if (N->getOpcode() == ISD::SRA) {
3493 bool BinOpRHSSignSet = BinOpCst->getAPIntValue().isNegative();
3494 if (BinOpRHSSignSet != HighBitSet)
3498 // Fold the constants, shifting the binop RHS by the shift amount.
3499 SDValue NewRHS = DAG.getNode(N->getOpcode(), LHS->getOperand(1).getDebugLoc(),
3501 LHS->getOperand(1), N->getOperand(1));
3503 // Create the new shift.
3504 SDValue NewShift = DAG.getNode(N->getOpcode(),
3505 LHS->getOperand(0).getDebugLoc(),
3506 VT, LHS->getOperand(0), N->getOperand(1));
3508 // Create the new binop.
3509 return DAG.getNode(LHS->getOpcode(), N->getDebugLoc(), VT, NewShift, NewRHS);
3512 SDValue DAGCombiner::visitSHL(SDNode *N) {
3513 SDValue N0 = N->getOperand(0);
3514 SDValue N1 = N->getOperand(1);
3515 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3516 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3517 EVT VT = N0.getValueType();
3518 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
3520 // fold (shl c1, c2) -> c1<<c2
3522 return DAG.FoldConstantArithmetic(ISD::SHL, VT, N0C, N1C);
3523 // fold (shl 0, x) -> 0
3524 if (N0C && N0C->isNullValue())
3526 // fold (shl x, c >= size(x)) -> undef
3527 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
3528 return DAG.getUNDEF(VT);
3529 // fold (shl x, 0) -> x
3530 if (N1C && N1C->isNullValue())
3532 // fold (shl undef, x) -> 0
3533 if (N0.getOpcode() == ISD::UNDEF)
3534 return DAG.getConstant(0, VT);
3535 // if (shl x, c) is known to be zero, return 0
3536 if (DAG.MaskedValueIsZero(SDValue(N, 0),
3537 APInt::getAllOnesValue(OpSizeInBits)))
3538 return DAG.getConstant(0, VT);
3539 // fold (shl x, (trunc (and y, c))) -> (shl x, (and (trunc y), (trunc c))).
3540 if (N1.getOpcode() == ISD::TRUNCATE &&
3541 N1.getOperand(0).getOpcode() == ISD::AND &&
3542 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
3543 SDValue N101 = N1.getOperand(0).getOperand(1);
3544 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
3545 EVT TruncVT = N1.getValueType();
3546 SDValue N100 = N1.getOperand(0).getOperand(0);
3547 APInt TruncC = N101C->getAPIntValue();
3548 TruncC = TruncC.trunc(TruncVT.getSizeInBits());
3549 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0,
3550 DAG.getNode(ISD::AND, N->getDebugLoc(), TruncVT,
3551 DAG.getNode(ISD::TRUNCATE,
3554 DAG.getConstant(TruncC, TruncVT)));
3558 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
3559 return SDValue(N, 0);
3561 // fold (shl (shl x, c1), c2) -> 0 or (shl x, (add c1, c2))
3562 if (N1C && N0.getOpcode() == ISD::SHL &&
3563 N0.getOperand(1).getOpcode() == ISD::Constant) {
3564 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
3565 uint64_t c2 = N1C->getZExtValue();
3566 if (c1 + c2 >= OpSizeInBits)
3567 return DAG.getConstant(0, VT);
3568 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0.getOperand(0),
3569 DAG.getConstant(c1 + c2, N1.getValueType()));
3572 // fold (shl (ext (shl x, c1)), c2) -> (ext (shl x, (add c1, c2)))
3573 // For this to be valid, the second form must not preserve any of the bits
3574 // that are shifted out by the inner shift in the first form. This means
3575 // the outer shift size must be >= the number of bits added by the ext.
3576 // As a corollary, we don't care what kind of ext it is.
3577 if (N1C && (N0.getOpcode() == ISD::ZERO_EXTEND ||
3578 N0.getOpcode() == ISD::ANY_EXTEND ||
3579 N0.getOpcode() == ISD::SIGN_EXTEND) &&
3580 N0.getOperand(0).getOpcode() == ISD::SHL &&
3581 isa<ConstantSDNode>(N0.getOperand(0)->getOperand(1))) {
3583 cast<ConstantSDNode>(N0.getOperand(0)->getOperand(1))->getZExtValue();
3584 uint64_t c2 = N1C->getZExtValue();
3585 EVT InnerShiftVT = N0.getOperand(0).getValueType();
3586 uint64_t InnerShiftSize = InnerShiftVT.getScalarType().getSizeInBits();
3587 if (c2 >= OpSizeInBits - InnerShiftSize) {
3588 if (c1 + c2 >= OpSizeInBits)
3589 return DAG.getConstant(0, VT);
3590 return DAG.getNode(ISD::SHL, N0->getDebugLoc(), VT,
3591 DAG.getNode(N0.getOpcode(), N0->getDebugLoc(), VT,
3592 N0.getOperand(0)->getOperand(0)),
3593 DAG.getConstant(c1 + c2, N1.getValueType()));
3597 // fold (shl (srl x, c1), c2) -> (and (shl x, (sub c2, c1), MASK) or
3598 // (and (srl x, (sub c1, c2), MASK)
3599 // Only fold this if the inner shift has no other uses -- if it does, folding
3600 // this will increase the total number of instructions.
3601 if (N1C && N0.getOpcode() == ISD::SRL && N0.hasOneUse() &&
3602 N0.getOperand(1).getOpcode() == ISD::Constant) {
3603 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
3604 if (c1 < VT.getSizeInBits()) {
3605 uint64_t c2 = N1C->getZExtValue();
3606 APInt Mask = APInt::getHighBitsSet(VT.getSizeInBits(),
3607 VT.getSizeInBits() - c1);
3610 Mask = Mask.shl(c2-c1);
3611 Shift = DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0.getOperand(0),
3612 DAG.getConstant(c2-c1, N1.getValueType()));
3614 Mask = Mask.lshr(c1-c2);
3615 Shift = DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0.getOperand(0),
3616 DAG.getConstant(c1-c2, N1.getValueType()));
3618 return DAG.getNode(ISD::AND, N0.getDebugLoc(), VT, Shift,
3619 DAG.getConstant(Mask, VT));
3622 // fold (shl (sra x, c1), c1) -> (and x, (shl -1, c1))
3623 if (N1C && N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1)) {
3624 SDValue HiBitsMask =
3625 DAG.getConstant(APInt::getHighBitsSet(VT.getSizeInBits(),
3626 VT.getSizeInBits() -
3627 N1C->getZExtValue()),
3629 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0.getOperand(0),
3634 SDValue NewSHL = visitShiftByConstant(N, N1C->getZExtValue());
3635 if (NewSHL.getNode())
3642 SDValue DAGCombiner::visitSRA(SDNode *N) {
3643 SDValue N0 = N->getOperand(0);
3644 SDValue N1 = N->getOperand(1);
3645 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3646 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3647 EVT VT = N0.getValueType();
3648 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
3650 // fold (sra c1, c2) -> (sra c1, c2)
3652 return DAG.FoldConstantArithmetic(ISD::SRA, VT, N0C, N1C);
3653 // fold (sra 0, x) -> 0
3654 if (N0C && N0C->isNullValue())
3656 // fold (sra -1, x) -> -1
3657 if (N0C && N0C->isAllOnesValue())
3659 // fold (sra x, (setge c, size(x))) -> undef
3660 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
3661 return DAG.getUNDEF(VT);
3662 // fold (sra x, 0) -> x
3663 if (N1C && N1C->isNullValue())
3665 // fold (sra (shl x, c1), c1) -> sext_inreg for some c1 and target supports
3667 if (N1C && N0.getOpcode() == ISD::SHL && N1 == N0.getOperand(1)) {
3668 unsigned LowBits = OpSizeInBits - (unsigned)N1C->getZExtValue();
3669 EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), LowBits);
3671 ExtVT = EVT::getVectorVT(*DAG.getContext(),
3672 ExtVT, VT.getVectorNumElements());
3673 if ((!LegalOperations ||
3674 TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, ExtVT)))
3675 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT,
3676 N0.getOperand(0), DAG.getValueType(ExtVT));
3679 // fold (sra (sra x, c1), c2) -> (sra x, (add c1, c2))
3680 if (N1C && N0.getOpcode() == ISD::SRA) {
3681 if (ConstantSDNode *C1 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
3682 unsigned Sum = N1C->getZExtValue() + C1->getZExtValue();
3683 if (Sum >= OpSizeInBits) Sum = OpSizeInBits-1;
3684 return DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, N0.getOperand(0),
3685 DAG.getConstant(Sum, N1C->getValueType(0)));
3689 // fold (sra (shl X, m), (sub result_size, n))
3690 // -> (sign_extend (trunc (shl X, (sub (sub result_size, n), m)))) for
3691 // result_size - n != m.
3692 // If truncate is free for the target sext(shl) is likely to result in better
3694 if (N0.getOpcode() == ISD::SHL) {
3695 // Get the two constanst of the shifts, CN0 = m, CN = n.
3696 const ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3698 // Determine what the truncate's result bitsize and type would be.
3700 EVT::getIntegerVT(*DAG.getContext(),
3701 OpSizeInBits - N1C->getZExtValue());
3702 // Determine the residual right-shift amount.
3703 signed ShiftAmt = N1C->getZExtValue() - N01C->getZExtValue();
3705 // If the shift is not a no-op (in which case this should be just a sign
3706 // extend already), the truncated to type is legal, sign_extend is legal
3707 // on that type, and the truncate to that type is both legal and free,
3708 // perform the transform.
3709 if ((ShiftAmt > 0) &&
3710 TLI.isOperationLegalOrCustom(ISD::SIGN_EXTEND, TruncVT) &&
3711 TLI.isOperationLegalOrCustom(ISD::TRUNCATE, VT) &&
3712 TLI.isTruncateFree(VT, TruncVT)) {
3714 SDValue Amt = DAG.getConstant(ShiftAmt,
3715 getShiftAmountTy(N0.getOperand(0).getValueType()));
3716 SDValue Shift = DAG.getNode(ISD::SRL, N0.getDebugLoc(), VT,
3717 N0.getOperand(0), Amt);
3718 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(), TruncVT,
3720 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(),
3721 N->getValueType(0), Trunc);
3726 // fold (sra x, (trunc (and y, c))) -> (sra x, (and (trunc y), (trunc c))).
3727 if (N1.getOpcode() == ISD::TRUNCATE &&
3728 N1.getOperand(0).getOpcode() == ISD::AND &&
3729 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
3730 SDValue N101 = N1.getOperand(0).getOperand(1);
3731 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
3732 EVT TruncVT = N1.getValueType();
3733 SDValue N100 = N1.getOperand(0).getOperand(0);
3734 APInt TruncC = N101C->getAPIntValue();
3735 TruncC = TruncC.trunc(TruncVT.getScalarType().getSizeInBits());
3736 return DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, N0,
3737 DAG.getNode(ISD::AND, N->getDebugLoc(),
3739 DAG.getNode(ISD::TRUNCATE,
3742 DAG.getConstant(TruncC, TruncVT)));
3746 // fold (sra (trunc (sr x, c1)), c2) -> (trunc (sra x, c1+c2))
3747 // if c1 is equal to the number of bits the trunc removes
3748 if (N0.getOpcode() == ISD::TRUNCATE &&
3749 (N0.getOperand(0).getOpcode() == ISD::SRL ||
3750 N0.getOperand(0).getOpcode() == ISD::SRA) &&
3751 N0.getOperand(0).hasOneUse() &&
3752 N0.getOperand(0).getOperand(1).hasOneUse() &&
3753 N1C && isa<ConstantSDNode>(N0.getOperand(0).getOperand(1))) {
3754 EVT LargeVT = N0.getOperand(0).getValueType();
3755 ConstantSDNode *LargeShiftAmt =
3756 cast<ConstantSDNode>(N0.getOperand(0).getOperand(1));
3758 if (LargeVT.getScalarType().getSizeInBits() - OpSizeInBits ==
3759 LargeShiftAmt->getZExtValue()) {
3761 DAG.getConstant(LargeShiftAmt->getZExtValue() + N1C->getZExtValue(),
3762 getShiftAmountTy(N0.getOperand(0).getOperand(0).getValueType()));
3763 SDValue SRA = DAG.getNode(ISD::SRA, N->getDebugLoc(), LargeVT,
3764 N0.getOperand(0).getOperand(0), Amt);
3765 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, SRA);
3769 // Simplify, based on bits shifted out of the LHS.
3770 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
3771 return SDValue(N, 0);
3774 // If the sign bit is known to be zero, switch this to a SRL.
3775 if (DAG.SignBitIsZero(N0))
3776 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0, N1);
3779 SDValue NewSRA = visitShiftByConstant(N, N1C->getZExtValue());
3780 if (NewSRA.getNode())
3787 SDValue DAGCombiner::visitSRL(SDNode *N) {
3788 SDValue N0 = N->getOperand(0);
3789 SDValue N1 = N->getOperand(1);
3790 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3791 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3792 EVT VT = N0.getValueType();
3793 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
3795 // fold (srl c1, c2) -> c1 >>u c2
3797 return DAG.FoldConstantArithmetic(ISD::SRL, VT, N0C, N1C);
3798 // fold (srl 0, x) -> 0
3799 if (N0C && N0C->isNullValue())
3801 // fold (srl x, c >= size(x)) -> undef
3802 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
3803 return DAG.getUNDEF(VT);
3804 // fold (srl x, 0) -> x
3805 if (N1C && N1C->isNullValue())
3807 // if (srl x, c) is known to be zero, return 0
3808 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
3809 APInt::getAllOnesValue(OpSizeInBits)))
3810 return DAG.getConstant(0, VT);
3812 // fold (srl (srl x, c1), c2) -> 0 or (srl x, (add c1, c2))
3813 if (N1C && N0.getOpcode() == ISD::SRL &&
3814 N0.getOperand(1).getOpcode() == ISD::Constant) {
3815 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
3816 uint64_t c2 = N1C->getZExtValue();
3817 if (c1 + c2 >= OpSizeInBits)
3818 return DAG.getConstant(0, VT);
3819 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0.getOperand(0),
3820 DAG.getConstant(c1 + c2, N1.getValueType()));
3823 // fold (srl (trunc (srl x, c1)), c2) -> 0 or (trunc (srl x, (add c1, c2)))
3824 if (N1C && N0.getOpcode() == ISD::TRUNCATE &&
3825 N0.getOperand(0).getOpcode() == ISD::SRL &&
3826 isa<ConstantSDNode>(N0.getOperand(0)->getOperand(1))) {
3828 cast<ConstantSDNode>(N0.getOperand(0)->getOperand(1))->getZExtValue();
3829 uint64_t c2 = N1C->getZExtValue();
3830 EVT InnerShiftVT = N0.getOperand(0).getValueType();
3831 EVT ShiftCountVT = N0.getOperand(0)->getOperand(1).getValueType();
3832 uint64_t InnerShiftSize = InnerShiftVT.getScalarType().getSizeInBits();
3833 // This is only valid if the OpSizeInBits + c1 = size of inner shift.
3834 if (c1 + OpSizeInBits == InnerShiftSize) {
3835 if (c1 + c2 >= InnerShiftSize)
3836 return DAG.getConstant(0, VT);
3837 return DAG.getNode(ISD::TRUNCATE, N0->getDebugLoc(), VT,
3838 DAG.getNode(ISD::SRL, N0->getDebugLoc(), InnerShiftVT,
3839 N0.getOperand(0)->getOperand(0),
3840 DAG.getConstant(c1 + c2, ShiftCountVT)));
3844 // fold (srl (shl x, c), c) -> (and x, cst2)
3845 if (N1C && N0.getOpcode() == ISD::SHL && N0.getOperand(1) == N1 &&
3846 N0.getValueSizeInBits() <= 64) {
3847 uint64_t ShAmt = N1C->getZExtValue()+64-N0.getValueSizeInBits();
3848 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0.getOperand(0),
3849 DAG.getConstant(~0ULL >> ShAmt, VT));
3853 // fold (srl (anyextend x), c) -> (anyextend (srl x, c))
3854 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
3855 // Shifting in all undef bits?
3856 EVT SmallVT = N0.getOperand(0).getValueType();
3857 if (N1C->getZExtValue() >= SmallVT.getSizeInBits())
3858 return DAG.getUNDEF(VT);
3860 if (!LegalTypes || TLI.isTypeDesirableForOp(ISD::SRL, SmallVT)) {
3861 uint64_t ShiftAmt = N1C->getZExtValue();
3862 SDValue SmallShift = DAG.getNode(ISD::SRL, N0.getDebugLoc(), SmallVT,
3864 DAG.getConstant(ShiftAmt, getShiftAmountTy(SmallVT)));
3865 AddToWorkList(SmallShift.getNode());
3866 return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, SmallShift);
3870 // fold (srl (sra X, Y), 31) -> (srl X, 31). This srl only looks at the sign
3871 // bit, which is unmodified by sra.
3872 if (N1C && N1C->getZExtValue() + 1 == VT.getSizeInBits()) {
3873 if (N0.getOpcode() == ISD::SRA)
3874 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0.getOperand(0), N1);
3877 // fold (srl (ctlz x), "5") -> x iff x has one bit set (the low bit).
3878 if (N1C && N0.getOpcode() == ISD::CTLZ &&
3879 N1C->getAPIntValue() == Log2_32(VT.getSizeInBits())) {
3880 APInt KnownZero, KnownOne;
3881 DAG.ComputeMaskedBits(N0.getOperand(0), KnownZero, KnownOne);
3883 // If any of the input bits are KnownOne, then the input couldn't be all
3884 // zeros, thus the result of the srl will always be zero.
3885 if (KnownOne.getBoolValue()) return DAG.getConstant(0, VT);
3887 // If all of the bits input the to ctlz node are known to be zero, then
3888 // the result of the ctlz is "32" and the result of the shift is one.
3889 APInt UnknownBits = ~KnownZero;
3890 if (UnknownBits == 0) return DAG.getConstant(1, VT);
3892 // Otherwise, check to see if there is exactly one bit input to the ctlz.
3893 if ((UnknownBits & (UnknownBits - 1)) == 0) {
3894 // Okay, we know that only that the single bit specified by UnknownBits
3895 // could be set on input to the CTLZ node. If this bit is set, the SRL
3896 // will return 0, if it is clear, it returns 1. Change the CTLZ/SRL pair
3897 // to an SRL/XOR pair, which is likely to simplify more.
3898 unsigned ShAmt = UnknownBits.countTrailingZeros();
3899 SDValue Op = N0.getOperand(0);
3902 Op = DAG.getNode(ISD::SRL, N0.getDebugLoc(), VT, Op,
3903 DAG.getConstant(ShAmt, getShiftAmountTy(Op.getValueType())));
3904 AddToWorkList(Op.getNode());
3907 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT,
3908 Op, DAG.getConstant(1, VT));
3912 // fold (srl x, (trunc (and y, c))) -> (srl x, (and (trunc y), (trunc c))).
3913 if (N1.getOpcode() == ISD::TRUNCATE &&
3914 N1.getOperand(0).getOpcode() == ISD::AND &&
3915 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
3916 SDValue N101 = N1.getOperand(0).getOperand(1);
3917 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
3918 EVT TruncVT = N1.getValueType();
3919 SDValue N100 = N1.getOperand(0).getOperand(0);
3920 APInt TruncC = N101C->getAPIntValue();
3921 TruncC = TruncC.trunc(TruncVT.getSizeInBits());
3922 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0,
3923 DAG.getNode(ISD::AND, N->getDebugLoc(),
3925 DAG.getNode(ISD::TRUNCATE,
3928 DAG.getConstant(TruncC, TruncVT)));
3932 // fold operands of srl based on knowledge that the low bits are not
3934 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
3935 return SDValue(N, 0);
3938 SDValue NewSRL = visitShiftByConstant(N, N1C->getZExtValue());
3939 if (NewSRL.getNode())
3943 // Attempt to convert a srl of a load into a narrower zero-extending load.
3944 SDValue NarrowLoad = ReduceLoadWidth(N);
3945 if (NarrowLoad.getNode())
3948 // Here is a common situation. We want to optimize:
3951 // %b = and i32 %a, 2
3952 // %c = srl i32 %b, 1
3953 // brcond i32 %c ...
3959 // %c = setcc eq %b, 0
3962 // However when after the source operand of SRL is optimized into AND, the SRL
3963 // itself may not be optimized further. Look for it and add the BRCOND into
3965 if (N->hasOneUse()) {
3966 SDNode *Use = *N->use_begin();
3967 if (Use->getOpcode() == ISD::BRCOND)
3969 else if (Use->getOpcode() == ISD::TRUNCATE && Use->hasOneUse()) {
3970 // Also look pass the truncate.
3971 Use = *Use->use_begin();
3972 if (Use->getOpcode() == ISD::BRCOND)
3980 SDValue DAGCombiner::visitCTLZ(SDNode *N) {
3981 SDValue N0 = N->getOperand(0);
3982 EVT VT = N->getValueType(0);
3984 // fold (ctlz c1) -> c2
3985 if (isa<ConstantSDNode>(N0))
3986 return DAG.getNode(ISD::CTLZ, N->getDebugLoc(), VT, N0);
3990 SDValue DAGCombiner::visitCTLZ_ZERO_UNDEF(SDNode *N) {
3991 SDValue N0 = N->getOperand(0);
3992 EVT VT = N->getValueType(0);
3994 // fold (ctlz_zero_undef c1) -> c2
3995 if (isa<ConstantSDNode>(N0))
3996 return DAG.getNode(ISD::CTLZ_ZERO_UNDEF, N->getDebugLoc(), VT, N0);
4000 SDValue DAGCombiner::visitCTTZ(SDNode *N) {
4001 SDValue N0 = N->getOperand(0);
4002 EVT VT = N->getValueType(0);
4004 // fold (cttz c1) -> c2
4005 if (isa<ConstantSDNode>(N0))
4006 return DAG.getNode(ISD::CTTZ, N->getDebugLoc(), VT, N0);
4010 SDValue DAGCombiner::visitCTTZ_ZERO_UNDEF(SDNode *N) {
4011 SDValue N0 = N->getOperand(0);
4012 EVT VT = N->getValueType(0);
4014 // fold (cttz_zero_undef c1) -> c2
4015 if (isa<ConstantSDNode>(N0))
4016 return DAG.getNode(ISD::CTTZ_ZERO_UNDEF, N->getDebugLoc(), VT, N0);
4020 SDValue DAGCombiner::visitCTPOP(SDNode *N) {
4021 SDValue N0 = N->getOperand(0);
4022 EVT VT = N->getValueType(0);
4024 // fold (ctpop c1) -> c2
4025 if (isa<ConstantSDNode>(N0))
4026 return DAG.getNode(ISD::CTPOP, N->getDebugLoc(), VT, N0);
4030 SDValue DAGCombiner::visitSELECT(SDNode *N) {
4031 SDValue N0 = N->getOperand(0);
4032 SDValue N1 = N->getOperand(1);
4033 SDValue N2 = N->getOperand(2);
4034 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
4035 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
4036 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2);
4037 EVT VT = N->getValueType(0);
4038 EVT VT0 = N0.getValueType();
4040 // fold (select C, X, X) -> X
4043 // fold (select true, X, Y) -> X
4044 if (N0C && !N0C->isNullValue())
4046 // fold (select false, X, Y) -> Y
4047 if (N0C && N0C->isNullValue())
4049 // fold (select C, 1, X) -> (or C, X)
4050 if (VT == MVT::i1 && N1C && N1C->getAPIntValue() == 1)
4051 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N2);
4052 // fold (select C, 0, 1) -> (xor C, 1)
4053 if (VT.isInteger() &&
4056 TLI.getBooleanContents(false) ==
4057 TargetLowering::ZeroOrOneBooleanContent)) &&
4058 N1C && N2C && N1C->isNullValue() && N2C->getAPIntValue() == 1) {
4061 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT0,
4062 N0, DAG.getConstant(1, VT0));
4063 XORNode = DAG.getNode(ISD::XOR, N0.getDebugLoc(), VT0,
4064 N0, DAG.getConstant(1, VT0));
4065 AddToWorkList(XORNode.getNode());
4067 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, XORNode);
4068 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, XORNode);
4070 // fold (select C, 0, X) -> (and (not C), X)
4071 if (VT == VT0 && VT == MVT::i1 && N1C && N1C->isNullValue()) {
4072 SDValue NOTNode = DAG.getNOT(N0.getDebugLoc(), N0, VT);
4073 AddToWorkList(NOTNode.getNode());
4074 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, NOTNode, N2);
4076 // fold (select C, X, 1) -> (or (not C), X)
4077 if (VT == VT0 && VT == MVT::i1 && N2C && N2C->getAPIntValue() == 1) {
4078 SDValue NOTNode = DAG.getNOT(N0.getDebugLoc(), N0, VT);
4079 AddToWorkList(NOTNode.getNode());
4080 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, NOTNode, N1);
4082 // fold (select C, X, 0) -> (and C, X)
4083 if (VT == MVT::i1 && N2C && N2C->isNullValue())
4084 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0, N1);
4085 // fold (select X, X, Y) -> (or X, Y)
4086 // fold (select X, 1, Y) -> (or X, Y)
4087 if (VT == MVT::i1 && (N0 == N1 || (N1C && N1C->getAPIntValue() == 1)))
4088 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N2);
4089 // fold (select X, Y, X) -> (and X, Y)
4090 // fold (select X, Y, 0) -> (and X, Y)
4091 if (VT == MVT::i1 && (N0 == N2 || (N2C && N2C->getAPIntValue() == 0)))
4092 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0, N1);
4094 // If we can fold this based on the true/false value, do so.
4095 if (SimplifySelectOps(N, N1, N2))
4096 return SDValue(N, 0); // Don't revisit N.
4098 // fold selects based on a setcc into other things, such as min/max/abs
4099 if (N0.getOpcode() == ISD::SETCC) {
4101 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
4102 // having to say they don't support SELECT_CC on every type the DAG knows
4103 // about, since there is no way to mark an opcode illegal at all value types
4104 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other) &&
4105 TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT))
4106 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT,
4107 N0.getOperand(0), N0.getOperand(1),
4108 N1, N2, N0.getOperand(2));
4109 return SimplifySelect(N->getDebugLoc(), N0, N1, N2);
4115 SDValue DAGCombiner::visitSELECT_CC(SDNode *N) {
4116 SDValue N0 = N->getOperand(0);
4117 SDValue N1 = N->getOperand(1);
4118 SDValue N2 = N->getOperand(2);
4119 SDValue N3 = N->getOperand(3);
4120 SDValue N4 = N->getOperand(4);
4121 ISD::CondCode CC = cast<CondCodeSDNode>(N4)->get();
4123 // fold select_cc lhs, rhs, x, x, cc -> x
4127 // Determine if the condition we're dealing with is constant
4128 SDValue SCC = SimplifySetCC(TLI.getSetCCResultType(N0.getValueType()),
4129 N0, N1, CC, N->getDebugLoc(), false);
4130 if (SCC.getNode()) AddToWorkList(SCC.getNode());
4132 if (ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.getNode())) {
4133 if (!SCCC->isNullValue())
4134 return N2; // cond always true -> true val
4136 return N3; // cond always false -> false val
4139 // Fold to a simpler select_cc
4140 if (SCC.getNode() && SCC.getOpcode() == ISD::SETCC)
4141 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), N2.getValueType(),
4142 SCC.getOperand(0), SCC.getOperand(1), N2, N3,
4145 // If we can fold this based on the true/false value, do so.
4146 if (SimplifySelectOps(N, N2, N3))
4147 return SDValue(N, 0); // Don't revisit N.
4149 // fold select_cc into other things, such as min/max/abs
4150 return SimplifySelectCC(N->getDebugLoc(), N0, N1, N2, N3, CC);
4153 SDValue DAGCombiner::visitSETCC(SDNode *N) {
4154 return SimplifySetCC(N->getValueType(0), N->getOperand(0), N->getOperand(1),
4155 cast<CondCodeSDNode>(N->getOperand(2))->get(),
4159 // ExtendUsesToFormExtLoad - Trying to extend uses of a load to enable this:
4160 // "fold ({s|z|a}ext (load x)) -> ({s|z|a}ext (truncate ({s|z|a}extload x)))"
4161 // transformation. Returns true if extension are possible and the above
4162 // mentioned transformation is profitable.
4163 static bool ExtendUsesToFormExtLoad(SDNode *N, SDValue N0,
4165 SmallVector<SDNode*, 4> &ExtendNodes,
4166 const TargetLowering &TLI) {
4167 bool HasCopyToRegUses = false;
4168 bool isTruncFree = TLI.isTruncateFree(N->getValueType(0), N0.getValueType());
4169 for (SDNode::use_iterator UI = N0.getNode()->use_begin(),
4170 UE = N0.getNode()->use_end();
4175 if (UI.getUse().getResNo() != N0.getResNo())
4177 // FIXME: Only extend SETCC N, N and SETCC N, c for now.
4178 if (ExtOpc != ISD::ANY_EXTEND && User->getOpcode() == ISD::SETCC) {
4179 ISD::CondCode CC = cast<CondCodeSDNode>(User->getOperand(2))->get();
4180 if (ExtOpc == ISD::ZERO_EXTEND && ISD::isSignedIntSetCC(CC))
4181 // Sign bits will be lost after a zext.
4184 for (unsigned i = 0; i != 2; ++i) {
4185 SDValue UseOp = User->getOperand(i);
4188 if (!isa<ConstantSDNode>(UseOp))
4193 ExtendNodes.push_back(User);
4196 // If truncates aren't free and there are users we can't
4197 // extend, it isn't worthwhile.
4200 // Remember if this value is live-out.
4201 if (User->getOpcode() == ISD::CopyToReg)
4202 HasCopyToRegUses = true;
4205 if (HasCopyToRegUses) {
4206 bool BothLiveOut = false;
4207 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
4209 SDUse &Use = UI.getUse();
4210 if (Use.getResNo() == 0 && Use.getUser()->getOpcode() == ISD::CopyToReg) {
4216 // Both unextended and extended values are live out. There had better be
4217 // a good reason for the transformation.
4218 return ExtendNodes.size();
4223 void DAGCombiner::ExtendSetCCUses(SmallVector<SDNode*, 4> SetCCs,
4224 SDValue Trunc, SDValue ExtLoad, DebugLoc DL,
4225 ISD::NodeType ExtType) {
4226 // Extend SetCC uses if necessary.
4227 for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
4228 SDNode *SetCC = SetCCs[i];
4229 SmallVector<SDValue, 4> Ops;
4231 for (unsigned j = 0; j != 2; ++j) {
4232 SDValue SOp = SetCC->getOperand(j);
4234 Ops.push_back(ExtLoad);
4236 Ops.push_back(DAG.getNode(ExtType, DL, ExtLoad->getValueType(0), SOp));
4239 Ops.push_back(SetCC->getOperand(2));
4240 CombineTo(SetCC, DAG.getNode(ISD::SETCC, DL, SetCC->getValueType(0),
4241 &Ops[0], Ops.size()));
4245 SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
4246 SDValue N0 = N->getOperand(0);
4247 EVT VT = N->getValueType(0);
4249 // fold (sext c1) -> c1
4250 if (isa<ConstantSDNode>(N0))
4251 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, N0);
4253 // fold (sext (sext x)) -> (sext x)
4254 // fold (sext (aext x)) -> (sext x)
4255 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
4256 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT,
4259 if (N0.getOpcode() == ISD::TRUNCATE) {
4260 // fold (sext (truncate (load x))) -> (sext (smaller load x))
4261 // fold (sext (truncate (srl (load x), c))) -> (sext (smaller load (x+c/n)))
4262 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4263 if (NarrowLoad.getNode()) {
4264 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4265 if (NarrowLoad.getNode() != N0.getNode()) {
4266 CombineTo(N0.getNode(), NarrowLoad);
4267 // CombineTo deleted the truncate, if needed, but not what's under it.
4270 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4273 // See if the value being truncated is already sign extended. If so, just
4274 // eliminate the trunc/sext pair.
4275 SDValue Op = N0.getOperand(0);
4276 unsigned OpBits = Op.getValueType().getScalarType().getSizeInBits();
4277 unsigned MidBits = N0.getValueType().getScalarType().getSizeInBits();
4278 unsigned DestBits = VT.getScalarType().getSizeInBits();
4279 unsigned NumSignBits = DAG.ComputeNumSignBits(Op);
4281 if (OpBits == DestBits) {
4282 // Op is i32, Mid is i8, and Dest is i32. If Op has more than 24 sign
4283 // bits, it is already ready.
4284 if (NumSignBits > DestBits-MidBits)
4286 } else if (OpBits < DestBits) {
4287 // Op is i32, Mid is i8, and Dest is i64. If Op has more than 24 sign
4288 // bits, just sext from i32.
4289 if (NumSignBits > OpBits-MidBits)
4290 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, Op);
4292 // Op is i64, Mid is i8, and Dest is i32. If Op has more than 56 sign
4293 // bits, just truncate to i32.
4294 if (NumSignBits > OpBits-MidBits)
4295 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, Op);
4298 // fold (sext (truncate x)) -> (sextinreg x).
4299 if (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG,
4300 N0.getValueType())) {
4301 if (OpBits < DestBits)
4302 Op = DAG.getNode(ISD::ANY_EXTEND, N0.getDebugLoc(), VT, Op);
4303 else if (OpBits > DestBits)
4304 Op = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(), VT, Op);
4305 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT, Op,
4306 DAG.getValueType(N0.getValueType()));
4310 // fold (sext (load x)) -> (sext (truncate (sextload x)))
4311 // None of the supported targets knows how to perform load and sign extend
4312 // on vectors in one instruction. We only perform this transformation on
4314 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
4315 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
4316 TLI.isLoadExtLegal(ISD::SEXTLOAD, N0.getValueType()))) {
4317 bool DoXform = true;
4318 SmallVector<SDNode*, 4> SetCCs;
4319 if (!N0.hasOneUse())
4320 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::SIGN_EXTEND, SetCCs, TLI);
4322 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4323 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, N->getDebugLoc(), VT,
4325 LN0->getBasePtr(), LN0->getPointerInfo(),
4327 LN0->isVolatile(), LN0->isNonTemporal(),
4328 LN0->getAlignment());
4329 CombineTo(N, ExtLoad);
4330 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
4331 N0.getValueType(), ExtLoad);
4332 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
4333 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
4335 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4339 // fold (sext (sextload x)) -> (sext (truncate (sextload x)))
4340 // fold (sext ( extload x)) -> (sext (truncate (sextload x)))
4341 if ((ISD::isSEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
4342 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
4343 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4344 EVT MemVT = LN0->getMemoryVT();
4345 if ((!LegalOperations && !LN0->isVolatile()) ||
4346 TLI.isLoadExtLegal(ISD::SEXTLOAD, MemVT)) {
4347 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, N->getDebugLoc(), VT,
4349 LN0->getBasePtr(), LN0->getPointerInfo(),
4351 LN0->isVolatile(), LN0->isNonTemporal(),
4352 LN0->getAlignment());
4353 CombineTo(N, ExtLoad);
4354 CombineTo(N0.getNode(),
4355 DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
4356 N0.getValueType(), ExtLoad),
4357 ExtLoad.getValue(1));
4358 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4362 // fold (sext (and/or/xor (load x), cst)) ->
4363 // (and/or/xor (sextload x), (sext cst))
4364 if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
4365 N0.getOpcode() == ISD::XOR) &&
4366 isa<LoadSDNode>(N0.getOperand(0)) &&
4367 N0.getOperand(1).getOpcode() == ISD::Constant &&
4368 TLI.isLoadExtLegal(ISD::SEXTLOAD, N0.getValueType()) &&
4369 (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
4370 LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
4371 if (LN0->getExtensionType() != ISD::ZEXTLOAD) {
4372 bool DoXform = true;
4373 SmallVector<SDNode*, 4> SetCCs;
4374 if (!N0.hasOneUse())
4375 DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::SIGN_EXTEND,
4378 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, LN0->getDebugLoc(), VT,
4379 LN0->getChain(), LN0->getBasePtr(),
4380 LN0->getPointerInfo(),
4383 LN0->isNonTemporal(),
4384 LN0->getAlignment());
4385 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4386 Mask = Mask.sext(VT.getSizeInBits());
4387 SDValue And = DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT,
4388 ExtLoad, DAG.getConstant(Mask, VT));
4389 SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
4390 N0.getOperand(0).getDebugLoc(),
4391 N0.getOperand(0).getValueType(), ExtLoad);
4393 CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
4394 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
4396 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4401 if (N0.getOpcode() == ISD::SETCC) {
4402 // sext(setcc) -> sext_in_reg(vsetcc) for vectors.
4403 // Only do this before legalize for now.
4404 if (VT.isVector() && !LegalOperations) {
4405 EVT N0VT = N0.getOperand(0).getValueType();
4406 // On some architectures (such as SSE/NEON/etc) the SETCC result type is
4407 // of the same size as the compared operands. Only optimize sext(setcc())
4408 // if this is the case.
4409 EVT SVT = TLI.getSetCCResultType(N0VT);
4411 // We know that the # elements of the results is the same as the
4412 // # elements of the compare (and the # elements of the compare result
4413 // for that matter). Check to see that they are the same size. If so,
4414 // we know that the element size of the sext'd result matches the
4415 // element size of the compare operands.
4416 if (VT.getSizeInBits() == SVT.getSizeInBits())
4417 return DAG.getSetCC(N->getDebugLoc(), VT, N0.getOperand(0),
4419 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4420 // If the desired elements are smaller or larger than the source
4421 // elements we can use a matching integer vector type and then
4422 // truncate/sign extend
4423 EVT MatchingElementType =
4424 EVT::getIntegerVT(*DAG.getContext(),
4425 N0VT.getScalarType().getSizeInBits());
4426 EVT MatchingVectorType =
4427 EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
4428 N0VT.getVectorNumElements());
4430 if (SVT == MatchingVectorType) {
4431 SDValue VsetCC = DAG.getSetCC(N->getDebugLoc(), MatchingVectorType,
4432 N0.getOperand(0), N0.getOperand(1),
4433 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4434 return DAG.getSExtOrTrunc(VsetCC, N->getDebugLoc(), VT);
4438 // sext(setcc x, y, cc) -> (select_cc x, y, -1, 0, cc)
4439 unsigned ElementWidth = VT.getScalarType().getSizeInBits();
4441 DAG.getConstant(APInt::getAllOnesValue(ElementWidth), VT);
4443 SimplifySelectCC(N->getDebugLoc(), N0.getOperand(0), N0.getOperand(1),
4444 NegOne, DAG.getConstant(0, VT),
4445 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
4446 if (SCC.getNode()) return SCC;
4447 if (!LegalOperations ||
4448 TLI.isOperationLegal(ISD::SETCC, TLI.getSetCCResultType(VT)))
4449 return DAG.getNode(ISD::SELECT, N->getDebugLoc(), VT,
4450 DAG.getSetCC(N->getDebugLoc(),
4451 TLI.getSetCCResultType(VT),
4452 N0.getOperand(0), N0.getOperand(1),
4453 cast<CondCodeSDNode>(N0.getOperand(2))->get()),
4454 NegOne, DAG.getConstant(0, VT));
4457 // fold (sext x) -> (zext x) if the sign bit is known zero.
4458 if ((!LegalOperations || TLI.isOperationLegal(ISD::ZERO_EXTEND, VT)) &&
4459 DAG.SignBitIsZero(N0))
4460 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, N0);
4465 // isTruncateOf - If N is a truncate of some other value, return true, record
4466 // the value being truncated in Op and which of Op's bits are zero in KnownZero.
4467 // This function computes KnownZero to avoid a duplicated call to
4468 // ComputeMaskedBits in the caller.
4469 static bool isTruncateOf(SelectionDAG &DAG, SDValue N, SDValue &Op,
4472 if (N->getOpcode() == ISD::TRUNCATE) {
4473 Op = N->getOperand(0);
4474 DAG.ComputeMaskedBits(Op, KnownZero, KnownOne);
4478 if (N->getOpcode() != ISD::SETCC || N->getValueType(0) != MVT::i1 ||
4479 cast<CondCodeSDNode>(N->getOperand(2))->get() != ISD::SETNE)
4482 SDValue Op0 = N->getOperand(0);
4483 SDValue Op1 = N->getOperand(1);
4484 assert(Op0.getValueType() == Op1.getValueType());
4486 ConstantSDNode *COp0 = dyn_cast<ConstantSDNode>(Op0);
4487 ConstantSDNode *COp1 = dyn_cast<ConstantSDNode>(Op1);
4488 if (COp0 && COp0->isNullValue())
4490 else if (COp1 && COp1->isNullValue())
4495 DAG.ComputeMaskedBits(Op, KnownZero, KnownOne);
4497 if (!(KnownZero | APInt(Op.getValueSizeInBits(), 1)).isAllOnesValue())
4503 SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) {
4504 SDValue N0 = N->getOperand(0);
4505 EVT VT = N->getValueType(0);
4507 // fold (zext c1) -> c1
4508 if (isa<ConstantSDNode>(N0))
4509 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, N0);
4510 // fold (zext (zext x)) -> (zext x)
4511 // fold (zext (aext x)) -> (zext x)
4512 if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
4513 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT,
4516 // fold (zext (truncate x)) -> (zext x) or
4517 // (zext (truncate x)) -> (truncate x)
4518 // This is valid when the truncated bits of x are already zero.
4519 // FIXME: We should extend this to work for vectors too.
4522 if (!VT.isVector() && isTruncateOf(DAG, N0, Op, KnownZero)) {
4523 APInt TruncatedBits =
4524 (Op.getValueSizeInBits() == N0.getValueSizeInBits()) ?
4525 APInt(Op.getValueSizeInBits(), 0) :
4526 APInt::getBitsSet(Op.getValueSizeInBits(),
4527 N0.getValueSizeInBits(),
4528 std::min(Op.getValueSizeInBits(),
4529 VT.getSizeInBits()));
4530 if (TruncatedBits == (KnownZero & TruncatedBits)) {
4531 if (VT.bitsGT(Op.getValueType()))
4532 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, Op);
4533 if (VT.bitsLT(Op.getValueType()))
4534 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, Op);
4540 // fold (zext (truncate (load x))) -> (zext (smaller load x))
4541 // fold (zext (truncate (srl (load x), c))) -> (zext (small load (x+c/n)))
4542 if (N0.getOpcode() == ISD::TRUNCATE) {
4543 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4544 if (NarrowLoad.getNode()) {
4545 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4546 if (NarrowLoad.getNode() != N0.getNode()) {
4547 CombineTo(N0.getNode(), NarrowLoad);
4548 // CombineTo deleted the truncate, if needed, but not what's under it.
4551 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4555 // fold (zext (truncate x)) -> (and x, mask)
4556 if (N0.getOpcode() == ISD::TRUNCATE &&
4557 (!LegalOperations || TLI.isOperationLegal(ISD::AND, VT))) {
4559 // fold (zext (truncate (load x))) -> (zext (smaller load x))
4560 // fold (zext (truncate (srl (load x), c))) -> (zext (smaller load (x+c/n)))
4561 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4562 if (NarrowLoad.getNode()) {
4563 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4564 if (NarrowLoad.getNode() != N0.getNode()) {
4565 CombineTo(N0.getNode(), NarrowLoad);
4566 // CombineTo deleted the truncate, if needed, but not what's under it.
4569 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4572 SDValue Op = N0.getOperand(0);
4573 if (Op.getValueType().bitsLT(VT)) {
4574 Op = DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, Op);
4575 AddToWorkList(Op.getNode());
4576 } else if (Op.getValueType().bitsGT(VT)) {
4577 Op = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, Op);
4578 AddToWorkList(Op.getNode());
4580 return DAG.getZeroExtendInReg(Op, N->getDebugLoc(),
4581 N0.getValueType().getScalarType());
4584 // Fold (zext (and (trunc x), cst)) -> (and x, cst),
4585 // if either of the casts is not free.
4586 if (N0.getOpcode() == ISD::AND &&
4587 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
4588 N0.getOperand(1).getOpcode() == ISD::Constant &&
4589 (!TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
4590 N0.getValueType()) ||
4591 !TLI.isZExtFree(N0.getValueType(), VT))) {
4592 SDValue X = N0.getOperand(0).getOperand(0);
4593 if (X.getValueType().bitsLT(VT)) {
4594 X = DAG.getNode(ISD::ANY_EXTEND, X.getDebugLoc(), VT, X);
4595 } else if (X.getValueType().bitsGT(VT)) {
4596 X = DAG.getNode(ISD::TRUNCATE, X.getDebugLoc(), VT, X);
4598 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4599 Mask = Mask.zext(VT.getSizeInBits());
4600 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
4601 X, DAG.getConstant(Mask, VT));
4604 // fold (zext (load x)) -> (zext (truncate (zextload x)))
4605 // None of the supported targets knows how to perform load and vector_zext
4606 // on vectors in one instruction. We only perform this transformation on
4608 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
4609 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
4610 TLI.isLoadExtLegal(ISD::ZEXTLOAD, N0.getValueType()))) {
4611 bool DoXform = true;
4612 SmallVector<SDNode*, 4> SetCCs;
4613 if (!N0.hasOneUse())
4614 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ZERO_EXTEND, SetCCs, TLI);
4616 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4617 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, N->getDebugLoc(), VT,
4619 LN0->getBasePtr(), LN0->getPointerInfo(),
4621 LN0->isVolatile(), LN0->isNonTemporal(),
4622 LN0->getAlignment());
4623 CombineTo(N, ExtLoad);
4624 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
4625 N0.getValueType(), ExtLoad);
4626 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
4628 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
4630 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4634 // fold (zext (and/or/xor (load x), cst)) ->
4635 // (and/or/xor (zextload x), (zext cst))
4636 if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
4637 N0.getOpcode() == ISD::XOR) &&
4638 isa<LoadSDNode>(N0.getOperand(0)) &&
4639 N0.getOperand(1).getOpcode() == ISD::Constant &&
4640 TLI.isLoadExtLegal(ISD::ZEXTLOAD, N0.getValueType()) &&
4641 (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
4642 LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
4643 if (LN0->getExtensionType() != ISD::SEXTLOAD) {
4644 bool DoXform = true;
4645 SmallVector<SDNode*, 4> SetCCs;
4646 if (!N0.hasOneUse())
4647 DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::ZERO_EXTEND,
4650 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, LN0->getDebugLoc(), VT,
4651 LN0->getChain(), LN0->getBasePtr(),
4652 LN0->getPointerInfo(),
4655 LN0->isNonTemporal(),
4656 LN0->getAlignment());
4657 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4658 Mask = Mask.zext(VT.getSizeInBits());
4659 SDValue And = DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT,
4660 ExtLoad, DAG.getConstant(Mask, VT));
4661 SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
4662 N0.getOperand(0).getDebugLoc(),
4663 N0.getOperand(0).getValueType(), ExtLoad);
4665 CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
4666 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
4668 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4673 // fold (zext (zextload x)) -> (zext (truncate (zextload x)))
4674 // fold (zext ( extload x)) -> (zext (truncate (zextload x)))
4675 if ((ISD::isZEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
4676 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
4677 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4678 EVT MemVT = LN0->getMemoryVT();
4679 if ((!LegalOperations && !LN0->isVolatile()) ||
4680 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT)) {
4681 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, N->getDebugLoc(), VT,
4683 LN0->getBasePtr(), LN0->getPointerInfo(),
4685 LN0->isVolatile(), LN0->isNonTemporal(),
4686 LN0->getAlignment());
4687 CombineTo(N, ExtLoad);
4688 CombineTo(N0.getNode(),
4689 DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(), N0.getValueType(),
4691 ExtLoad.getValue(1));
4692 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4696 if (N0.getOpcode() == ISD::SETCC) {
4697 if (!LegalOperations && VT.isVector()) {
4698 // zext(setcc) -> (and (vsetcc), (1, 1, ...) for vectors.
4699 // Only do this before legalize for now.
4700 EVT N0VT = N0.getOperand(0).getValueType();
4701 EVT EltVT = VT.getVectorElementType();
4702 SmallVector<SDValue,8> OneOps(VT.getVectorNumElements(),
4703 DAG.getConstant(1, EltVT));
4704 if (VT.getSizeInBits() == N0VT.getSizeInBits())
4705 // We know that the # elements of the results is the same as the
4706 // # elements of the compare (and the # elements of the compare result
4707 // for that matter). Check to see that they are the same size. If so,
4708 // we know that the element size of the sext'd result matches the
4709 // element size of the compare operands.
4710 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
4711 DAG.getSetCC(N->getDebugLoc(), VT, N0.getOperand(0),
4713 cast<CondCodeSDNode>(N0.getOperand(2))->get()),
4714 DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(), VT,
4715 &OneOps[0], OneOps.size()));
4717 // If the desired elements are smaller or larger than the source
4718 // elements we can use a matching integer vector type and then
4719 // truncate/sign extend
4720 EVT MatchingElementType =
4721 EVT::getIntegerVT(*DAG.getContext(),
4722 N0VT.getScalarType().getSizeInBits());
4723 EVT MatchingVectorType =
4724 EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
4725 N0VT.getVectorNumElements());
4727 DAG.getSetCC(N->getDebugLoc(), MatchingVectorType, N0.getOperand(0),
4729 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4730 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
4731 DAG.getSExtOrTrunc(VsetCC, N->getDebugLoc(), VT),
4732 DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(), VT,
4733 &OneOps[0], OneOps.size()));
4736 // zext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
4738 SimplifySelectCC(N->getDebugLoc(), N0.getOperand(0), N0.getOperand(1),
4739 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
4740 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
4741 if (SCC.getNode()) return SCC;
4744 // (zext (shl (zext x), cst)) -> (shl (zext x), cst)
4745 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL) &&
4746 isa<ConstantSDNode>(N0.getOperand(1)) &&
4747 N0.getOperand(0).getOpcode() == ISD::ZERO_EXTEND &&
4749 SDValue ShAmt = N0.getOperand(1);
4750 unsigned ShAmtVal = cast<ConstantSDNode>(ShAmt)->getZExtValue();
4751 if (N0.getOpcode() == ISD::SHL) {
4752 SDValue InnerZExt = N0.getOperand(0);
4753 // If the original shl may be shifting out bits, do not perform this
4755 unsigned KnownZeroBits = InnerZExt.getValueType().getSizeInBits() -
4756 InnerZExt.getOperand(0).getValueType().getSizeInBits();
4757 if (ShAmtVal > KnownZeroBits)
4761 DebugLoc DL = N->getDebugLoc();
4763 // Ensure that the shift amount is wide enough for the shifted value.
4764 if (VT.getSizeInBits() >= 256)
4765 ShAmt = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, ShAmt);
4767 return DAG.getNode(N0.getOpcode(), DL, VT,
4768 DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0)),
4775 SDValue DAGCombiner::visitANY_EXTEND(SDNode *N) {
4776 SDValue N0 = N->getOperand(0);
4777 EVT VT = N->getValueType(0);
4779 // fold (aext c1) -> c1
4780 if (isa<ConstantSDNode>(N0))
4781 return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, N0);
4782 // fold (aext (aext x)) -> (aext x)
4783 // fold (aext (zext x)) -> (zext x)
4784 // fold (aext (sext x)) -> (sext x)
4785 if (N0.getOpcode() == ISD::ANY_EXTEND ||
4786 N0.getOpcode() == ISD::ZERO_EXTEND ||
4787 N0.getOpcode() == ISD::SIGN_EXTEND)
4788 return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT, N0.getOperand(0));
4790 // fold (aext (truncate (load x))) -> (aext (smaller load x))
4791 // fold (aext (truncate (srl (load x), c))) -> (aext (small load (x+c/n)))
4792 if (N0.getOpcode() == ISD::TRUNCATE) {
4793 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4794 if (NarrowLoad.getNode()) {
4795 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4796 if (NarrowLoad.getNode() != N0.getNode()) {
4797 CombineTo(N0.getNode(), NarrowLoad);
4798 // CombineTo deleted the truncate, if needed, but not what's under it.
4801 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4805 // fold (aext (truncate x))
4806 if (N0.getOpcode() == ISD::TRUNCATE) {
4807 SDValue TruncOp = N0.getOperand(0);
4808 if (TruncOp.getValueType() == VT)
4809 return TruncOp; // x iff x size == zext size.
4810 if (TruncOp.getValueType().bitsGT(VT))
4811 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, TruncOp);
4812 return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, TruncOp);
4815 // Fold (aext (and (trunc x), cst)) -> (and x, cst)
4816 // if the trunc is not free.
4817 if (N0.getOpcode() == ISD::AND &&
4818 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
4819 N0.getOperand(1).getOpcode() == ISD::Constant &&
4820 !TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
4821 N0.getValueType())) {
4822 SDValue X = N0.getOperand(0).getOperand(0);
4823 if (X.getValueType().bitsLT(VT)) {
4824 X = DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, X);
4825 } else if (X.getValueType().bitsGT(VT)) {
4826 X = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, X);
4828 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4829 Mask = Mask.zext(VT.getSizeInBits());
4830 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
4831 X, DAG.getConstant(Mask, VT));
4834 // fold (aext (load x)) -> (aext (truncate (extload x)))
4835 // None of the supported targets knows how to perform load and any_ext
4836 // on vectors in one instruction. We only perform this transformation on
4838 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
4839 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
4840 TLI.isLoadExtLegal(ISD::EXTLOAD, N0.getValueType()))) {
4841 bool DoXform = true;
4842 SmallVector<SDNode*, 4> SetCCs;
4843 if (!N0.hasOneUse())
4844 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ANY_EXTEND, SetCCs, TLI);
4846 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4847 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, N->getDebugLoc(), VT,
4849 LN0->getBasePtr(), LN0->getPointerInfo(),
4851 LN0->isVolatile(), LN0->isNonTemporal(),
4852 LN0->getAlignment());
4853 CombineTo(N, ExtLoad);
4854 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
4855 N0.getValueType(), ExtLoad);
4856 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
4857 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
4859 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4863 // fold (aext (zextload x)) -> (aext (truncate (zextload x)))
4864 // fold (aext (sextload x)) -> (aext (truncate (sextload x)))
4865 // fold (aext ( extload x)) -> (aext (truncate (extload x)))
4866 if (N0.getOpcode() == ISD::LOAD &&
4867 !ISD::isNON_EXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
4869 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4870 EVT MemVT = LN0->getMemoryVT();
4871 SDValue ExtLoad = DAG.getExtLoad(LN0->getExtensionType(), N->getDebugLoc(),
4872 VT, LN0->getChain(), LN0->getBasePtr(),
4873 LN0->getPointerInfo(), MemVT,
4874 LN0->isVolatile(), LN0->isNonTemporal(),
4875 LN0->getAlignment());
4876 CombineTo(N, ExtLoad);
4877 CombineTo(N0.getNode(),
4878 DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
4879 N0.getValueType(), ExtLoad),
4880 ExtLoad.getValue(1));
4881 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4884 if (N0.getOpcode() == ISD::SETCC) {
4885 // aext(setcc) -> sext_in_reg(vsetcc) for vectors.
4886 // Only do this before legalize for now.
4887 if (VT.isVector() && !LegalOperations) {
4888 EVT N0VT = N0.getOperand(0).getValueType();
4889 // We know that the # elements of the results is the same as the
4890 // # elements of the compare (and the # elements of the compare result
4891 // for that matter). Check to see that they are the same size. If so,
4892 // we know that the element size of the sext'd result matches the
4893 // element size of the compare operands.
4894 if (VT.getSizeInBits() == N0VT.getSizeInBits())
4895 return DAG.getSetCC(N->getDebugLoc(), VT, N0.getOperand(0),
4897 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4898 // If the desired elements are smaller or larger than the source
4899 // elements we can use a matching integer vector type and then
4900 // truncate/sign extend
4902 EVT MatchingElementType =
4903 EVT::getIntegerVT(*DAG.getContext(),
4904 N0VT.getScalarType().getSizeInBits());
4905 EVT MatchingVectorType =
4906 EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
4907 N0VT.getVectorNumElements());
4909 DAG.getSetCC(N->getDebugLoc(), MatchingVectorType, N0.getOperand(0),
4911 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4912 return DAG.getSExtOrTrunc(VsetCC, N->getDebugLoc(), VT);
4916 // aext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
4918 SimplifySelectCC(N->getDebugLoc(), N0.getOperand(0), N0.getOperand(1),
4919 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
4920 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
4928 /// GetDemandedBits - See if the specified operand can be simplified with the
4929 /// knowledge that only the bits specified by Mask are used. If so, return the
4930 /// simpler operand, otherwise return a null SDValue.
4931 SDValue DAGCombiner::GetDemandedBits(SDValue V, const APInt &Mask) {
4932 switch (V.getOpcode()) {
4934 case ISD::Constant: {
4935 const ConstantSDNode *CV = cast<ConstantSDNode>(V.getNode());
4936 assert(CV != 0 && "Const value should be ConstSDNode.");
4937 const APInt &CVal = CV->getAPIntValue();
4938 APInt NewVal = CVal & Mask;
4939 if (NewVal != CVal) {
4940 return DAG.getConstant(NewVal, V.getValueType());
4946 // If the LHS or RHS don't contribute bits to the or, drop them.
4947 if (DAG.MaskedValueIsZero(V.getOperand(0), Mask))
4948 return V.getOperand(1);
4949 if (DAG.MaskedValueIsZero(V.getOperand(1), Mask))
4950 return V.getOperand(0);
4953 // Only look at single-use SRLs.
4954 if (!V.getNode()->hasOneUse())
4956 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(V.getOperand(1))) {
4957 // See if we can recursively simplify the LHS.
4958 unsigned Amt = RHSC->getZExtValue();
4960 // Watch out for shift count overflow though.
4961 if (Amt >= Mask.getBitWidth()) break;
4962 APInt NewMask = Mask << Amt;
4963 SDValue SimplifyLHS = GetDemandedBits(V.getOperand(0), NewMask);
4964 if (SimplifyLHS.getNode())
4965 return DAG.getNode(ISD::SRL, V.getDebugLoc(), V.getValueType(),
4966 SimplifyLHS, V.getOperand(1));
4972 /// ReduceLoadWidth - If the result of a wider load is shifted to right of N
4973 /// bits and then truncated to a narrower type and where N is a multiple
4974 /// of number of bits of the narrower type, transform it to a narrower load
4975 /// from address + N / num of bits of new type. If the result is to be
4976 /// extended, also fold the extension to form a extending load.
4977 SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) {
4978 unsigned Opc = N->getOpcode();
4980 ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
4981 SDValue N0 = N->getOperand(0);
4982 EVT VT = N->getValueType(0);
4985 // This transformation isn't valid for vector loads.
4989 // Special case: SIGN_EXTEND_INREG is basically truncating to ExtVT then
4991 if (Opc == ISD::SIGN_EXTEND_INREG) {
4992 ExtType = ISD::SEXTLOAD;
4993 ExtVT = cast<VTSDNode>(N->getOperand(1))->getVT();
4994 } else if (Opc == ISD::SRL) {
4995 // Another special-case: SRL is basically zero-extending a narrower value.
4996 ExtType = ISD::ZEXTLOAD;
4998 ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1));
4999 if (!N01) return SDValue();
5000 ExtVT = EVT::getIntegerVT(*DAG.getContext(),
5001 VT.getSizeInBits() - N01->getZExtValue());
5003 if (LegalOperations && !TLI.isLoadExtLegal(ExtType, ExtVT))
5006 unsigned EVTBits = ExtVT.getSizeInBits();
5008 // Do not generate loads of non-round integer types since these can
5009 // be expensive (and would be wrong if the type is not byte sized).
5010 if (!ExtVT.isRound())
5014 if (N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
5015 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
5016 ShAmt = N01->getZExtValue();
5017 // Is the shift amount a multiple of size of VT?
5018 if ((ShAmt & (EVTBits-1)) == 0) {
5019 N0 = N0.getOperand(0);
5020 // Is the load width a multiple of size of VT?
5021 if ((N0.getValueType().getSizeInBits() & (EVTBits-1)) != 0)
5025 // At this point, we must have a load or else we can't do the transform.
5026 if (!isa<LoadSDNode>(N0)) return SDValue();
5028 // If the shift amount is larger than the input type then we're not
5029 // accessing any of the loaded bytes. If the load was a zextload/extload
5030 // then the result of the shift+trunc is zero/undef (handled elsewhere).
5031 // If the load was a sextload then the result is a splat of the sign bit
5032 // of the extended byte. This is not worth optimizing for.
5033 if (ShAmt >= cast<LoadSDNode>(N0)->getMemoryVT().getSizeInBits())
5038 // If the load is shifted left (and the result isn't shifted back right),
5039 // we can fold the truncate through the shift.
5040 unsigned ShLeftAmt = 0;
5041 if (ShAmt == 0 && N0.getOpcode() == ISD::SHL && N0.hasOneUse() &&
5042 ExtVT == VT && TLI.isNarrowingProfitable(N0.getValueType(), VT)) {
5043 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
5044 ShLeftAmt = N01->getZExtValue();
5045 N0 = N0.getOperand(0);
5049 // If we haven't found a load, we can't narrow it. Don't transform one with
5050 // multiple uses, this would require adding a new load.
5051 if (!isa<LoadSDNode>(N0) || !N0.hasOneUse() ||
5052 // Don't change the width of a volatile load.
5053 cast<LoadSDNode>(N0)->isVolatile())
5056 // Verify that we are actually reducing a load width here.
5057 if (cast<LoadSDNode>(N0)->getMemoryVT().getSizeInBits() < EVTBits)
5060 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5061 EVT PtrType = N0.getOperand(1).getValueType();
5063 if (PtrType == MVT::Untyped || PtrType.isExtended())
5064 // It's not possible to generate a constant of extended or untyped type.
5067 // For big endian targets, we need to adjust the offset to the pointer to
5068 // load the correct bytes.
5069 if (TLI.isBigEndian()) {
5070 unsigned LVTStoreBits = LN0->getMemoryVT().getStoreSizeInBits();
5071 unsigned EVTStoreBits = ExtVT.getStoreSizeInBits();
5072 ShAmt = LVTStoreBits - EVTStoreBits - ShAmt;
5075 uint64_t PtrOff = ShAmt / 8;
5076 unsigned NewAlign = MinAlign(LN0->getAlignment(), PtrOff);
5077 SDValue NewPtr = DAG.getNode(ISD::ADD, LN0->getDebugLoc(),
5078 PtrType, LN0->getBasePtr(),
5079 DAG.getConstant(PtrOff, PtrType));
5080 AddToWorkList(NewPtr.getNode());
5083 if (ExtType == ISD::NON_EXTLOAD)
5084 Load = DAG.getLoad(VT, N0.getDebugLoc(), LN0->getChain(), NewPtr,
5085 LN0->getPointerInfo().getWithOffset(PtrOff),
5086 LN0->isVolatile(), LN0->isNonTemporal(),
5087 LN0->isInvariant(), NewAlign);
5089 Load = DAG.getExtLoad(ExtType, N0.getDebugLoc(), VT, LN0->getChain(),NewPtr,
5090 LN0->getPointerInfo().getWithOffset(PtrOff),
5091 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
5094 // Replace the old load's chain with the new load's chain.
5095 WorkListRemover DeadNodes(*this);
5096 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));
5098 // Shift the result left, if we've swallowed a left shift.
5099 SDValue Result = Load;
5100 if (ShLeftAmt != 0) {
5101 EVT ShImmTy = getShiftAmountTy(Result.getValueType());
5102 if (!isUIntN(ShImmTy.getSizeInBits(), ShLeftAmt))
5104 Result = DAG.getNode(ISD::SHL, N0.getDebugLoc(), VT,
5105 Result, DAG.getConstant(ShLeftAmt, ShImmTy));
5108 // Return the new loaded value.
5112 SDValue DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
5113 SDValue N0 = N->getOperand(0);
5114 SDValue N1 = N->getOperand(1);
5115 EVT VT = N->getValueType(0);
5116 EVT EVT = cast<VTSDNode>(N1)->getVT();
5117 unsigned VTBits = VT.getScalarType().getSizeInBits();
5118 unsigned EVTBits = EVT.getScalarType().getSizeInBits();
5120 // fold (sext_in_reg c1) -> c1
5121 if (isa<ConstantSDNode>(N0) || N0.getOpcode() == ISD::UNDEF)
5122 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT, N0, N1);
5124 // If the input is already sign extended, just drop the extension.
5125 if (DAG.ComputeNumSignBits(N0) >= VTBits-EVTBits+1)
5128 // fold (sext_in_reg (sext_in_reg x, VT2), VT1) -> (sext_in_reg x, minVT) pt2
5129 if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
5130 EVT.bitsLT(cast<VTSDNode>(N0.getOperand(1))->getVT())) {
5131 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT,
5132 N0.getOperand(0), N1);
5135 // fold (sext_in_reg (sext x)) -> (sext x)
5136 // fold (sext_in_reg (aext x)) -> (sext x)
5137 // if x is small enough.
5138 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND) {
5139 SDValue N00 = N0.getOperand(0);
5140 if (N00.getValueType().getScalarType().getSizeInBits() <= EVTBits &&
5141 (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND, VT)))
5142 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, N00, N1);
5145 // fold (sext_in_reg x) -> (zext_in_reg x) if the sign bit is known zero.
5146 if (DAG.MaskedValueIsZero(N0, APInt::getBitsSet(VTBits, EVTBits-1, EVTBits)))
5147 return DAG.getZeroExtendInReg(N0, N->getDebugLoc(), EVT);
5149 // fold operands of sext_in_reg based on knowledge that the top bits are not
5151 if (SimplifyDemandedBits(SDValue(N, 0)))
5152 return SDValue(N, 0);
5154 // fold (sext_in_reg (load x)) -> (smaller sextload x)
5155 // fold (sext_in_reg (srl (load x), c)) -> (smaller sextload (x+c/evtbits))
5156 SDValue NarrowLoad = ReduceLoadWidth(N);
5157 if (NarrowLoad.getNode())
5160 // fold (sext_in_reg (srl X, 24), i8) -> (sra X, 24)
5161 // fold (sext_in_reg (srl X, 23), i8) -> (sra X, 23) iff possible.
5162 // We already fold "(sext_in_reg (srl X, 25), i8) -> srl X, 25" above.
5163 if (N0.getOpcode() == ISD::SRL) {
5164 if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
5165 if (ShAmt->getZExtValue()+EVTBits <= VTBits) {
5166 // We can turn this into an SRA iff the input to the SRL is already sign
5168 unsigned InSignBits = DAG.ComputeNumSignBits(N0.getOperand(0));
5169 if (VTBits-(ShAmt->getZExtValue()+EVTBits) < InSignBits)
5170 return DAG.getNode(ISD::SRA, N->getDebugLoc(), VT,
5171 N0.getOperand(0), N0.getOperand(1));
5175 // fold (sext_inreg (extload x)) -> (sextload x)
5176 if (ISD::isEXTLoad(N0.getNode()) &&
5177 ISD::isUNINDEXEDLoad(N0.getNode()) &&
5178 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
5179 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
5180 TLI.isLoadExtLegal(ISD::SEXTLOAD, EVT))) {
5181 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5182 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, N->getDebugLoc(), VT,
5184 LN0->getBasePtr(), LN0->getPointerInfo(),
5186 LN0->isVolatile(), LN0->isNonTemporal(),
5187 LN0->getAlignment());
5188 CombineTo(N, ExtLoad);
5189 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
5190 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5192 // fold (sext_inreg (zextload x)) -> (sextload x) iff load has one use
5193 if (ISD::isZEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
5195 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
5196 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
5197 TLI.isLoadExtLegal(ISD::SEXTLOAD, EVT))) {
5198 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5199 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, N->getDebugLoc(), VT,
5201 LN0->getBasePtr(), LN0->getPointerInfo(),
5203 LN0->isVolatile(), LN0->isNonTemporal(),
5204 LN0->getAlignment());
5205 CombineTo(N, ExtLoad);
5206 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
5207 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5210 // Form (sext_inreg (bswap >> 16)) or (sext_inreg (rotl (bswap) 16))
5211 if (EVTBits <= 16 && N0.getOpcode() == ISD::OR) {
5212 SDValue BSwap = MatchBSwapHWordLow(N0.getNode(), N0.getOperand(0),
5213 N0.getOperand(1), false);
5214 if (BSwap.getNode() != 0)
5215 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT,
5222 SDValue DAGCombiner::visitTRUNCATE(SDNode *N) {
5223 SDValue N0 = N->getOperand(0);
5224 EVT VT = N->getValueType(0);
5225 bool isLE = TLI.isLittleEndian();
5228 if (N0.getValueType() == N->getValueType(0))
5230 // fold (truncate c1) -> c1
5231 if (isa<ConstantSDNode>(N0))
5232 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, N0);
5233 // fold (truncate (truncate x)) -> (truncate x)
5234 if (N0.getOpcode() == ISD::TRUNCATE)
5235 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, N0.getOperand(0));
5236 // fold (truncate (ext x)) -> (ext x) or (truncate x) or x
5237 if (N0.getOpcode() == ISD::ZERO_EXTEND ||
5238 N0.getOpcode() == ISD::SIGN_EXTEND ||
5239 N0.getOpcode() == ISD::ANY_EXTEND) {
5240 if (N0.getOperand(0).getValueType().bitsLT(VT))
5241 // if the source is smaller than the dest, we still need an extend
5242 return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT,
5244 if (N0.getOperand(0).getValueType().bitsGT(VT))
5245 // if the source is larger than the dest, than we just need the truncate
5246 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, N0.getOperand(0));
5247 // if the source and dest are the same type, we can drop both the extend
5248 // and the truncate.
5249 return N0.getOperand(0);
5252 // Fold extract-and-trunc into a narrow extract. For example:
5253 // i64 x = EXTRACT_VECTOR_ELT(v2i64 val, i32 1)
5254 // i32 y = TRUNCATE(i64 x)
5256 // v16i8 b = BITCAST (v2i64 val)
5257 // i8 x = EXTRACT_VECTOR_ELT(v16i8 b, i32 8)
5259 // Note: We only run this optimization after type legalization (which often
5260 // creates this pattern) and before operation legalization after which
5261 // we need to be more careful about the vector instructions that we generate.
5262 if (N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
5263 LegalTypes && !LegalOperations && N0->hasOneUse()) {
5265 EVT VecTy = N0.getOperand(0).getValueType();
5266 EVT ExTy = N0.getValueType();
5267 EVT TrTy = N->getValueType(0);
5269 unsigned NumElem = VecTy.getVectorNumElements();
5270 unsigned SizeRatio = ExTy.getSizeInBits()/TrTy.getSizeInBits();
5272 EVT NVT = EVT::getVectorVT(*DAG.getContext(), TrTy, SizeRatio * NumElem);
5273 assert(NVT.getSizeInBits() == VecTy.getSizeInBits() && "Invalid Size");
5275 SDValue EltNo = N0->getOperand(1);
5276 if (isa<ConstantSDNode>(EltNo) && isTypeLegal(NVT)) {
5277 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
5278 EVT IndexTy = N0->getOperand(1).getValueType();
5279 int Index = isLE ? (Elt*SizeRatio) : (Elt*SizeRatio + (SizeRatio-1));
5281 SDValue V = DAG.getNode(ISD::BITCAST, N->getDebugLoc(),
5282 NVT, N0.getOperand(0));
5284 return DAG.getNode(ISD::EXTRACT_VECTOR_ELT,
5285 N->getDebugLoc(), TrTy, V,
5286 DAG.getConstant(Index, IndexTy));
5290 // See if we can simplify the input to this truncate through knowledge that
5291 // only the low bits are being used.
5292 // For example "trunc (or (shl x, 8), y)" // -> trunc y
5293 // Currently we only perform this optimization on scalars because vectors
5294 // may have different active low bits.
5295 if (!VT.isVector()) {
5297 GetDemandedBits(N0, APInt::getLowBitsSet(N0.getValueSizeInBits(),
5298 VT.getSizeInBits()));
5299 if (Shorter.getNode())
5300 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, Shorter);
5302 // fold (truncate (load x)) -> (smaller load x)
5303 // fold (truncate (srl (load x), c)) -> (smaller load (x+c/evtbits))
5304 if (!LegalTypes || TLI.isTypeDesirableForOp(N0.getOpcode(), VT)) {
5305 SDValue Reduced = ReduceLoadWidth(N);
5306 if (Reduced.getNode())
5309 // fold (trunc (concat ... x ...)) -> (concat ..., (trunc x), ...)),
5310 // where ... are all 'undef'.
5311 if (N0.getOpcode() == ISD::CONCAT_VECTORS && !LegalTypes) {
5312 SmallVector<EVT, 8> VTs;
5315 unsigned NumDefs = 0;
5317 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i) {
5318 SDValue X = N0.getOperand(i);
5319 if (X.getOpcode() != ISD::UNDEF) {
5324 // Stop if more than one members are non-undef.
5327 VTs.push_back(EVT::getVectorVT(*DAG.getContext(),
5328 VT.getVectorElementType(),
5329 X.getValueType().getVectorNumElements()));
5333 return DAG.getUNDEF(VT);
5336 assert(V.getNode() && "The single defined operand is empty!");
5337 SmallVector<SDValue, 8> Opnds;
5338 for (unsigned i = 0, e = VTs.size(); i != e; ++i) {
5340 Opnds.push_back(DAG.getUNDEF(VTs[i]));
5343 SDValue NV = DAG.getNode(ISD::TRUNCATE, V.getDebugLoc(), VTs[i], V);
5344 AddToWorkList(NV.getNode());
5345 Opnds.push_back(NV);
5347 return DAG.getNode(ISD::CONCAT_VECTORS, N->getDebugLoc(), VT,
5348 &Opnds[0], Opnds.size());
5352 // Simplify the operands using demanded-bits information.
5353 if (!VT.isVector() &&
5354 SimplifyDemandedBits(SDValue(N, 0)))
5355 return SDValue(N, 0);
5360 static SDNode *getBuildPairElt(SDNode *N, unsigned i) {
5361 SDValue Elt = N->getOperand(i);
5362 if (Elt.getOpcode() != ISD::MERGE_VALUES)
5363 return Elt.getNode();
5364 return Elt.getOperand(Elt.getResNo()).getNode();
5367 /// CombineConsecutiveLoads - build_pair (load, load) -> load
5368 /// if load locations are consecutive.
5369 SDValue DAGCombiner::CombineConsecutiveLoads(SDNode *N, EVT VT) {
5370 assert(N->getOpcode() == ISD::BUILD_PAIR);
5372 LoadSDNode *LD1 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 0));
5373 LoadSDNode *LD2 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 1));
5374 if (!LD1 || !LD2 || !ISD::isNON_EXTLoad(LD1) || !LD1->hasOneUse() ||
5375 LD1->getPointerInfo().getAddrSpace() !=
5376 LD2->getPointerInfo().getAddrSpace())
5378 EVT LD1VT = LD1->getValueType(0);
5380 if (ISD::isNON_EXTLoad(LD2) &&
5382 // If both are volatile this would reduce the number of volatile loads.
5383 // If one is volatile it might be ok, but play conservative and bail out.
5384 !LD1->isVolatile() &&
5385 !LD2->isVolatile() &&
5386 DAG.isConsecutiveLoad(LD2, LD1, LD1VT.getSizeInBits()/8, 1)) {
5387 unsigned Align = LD1->getAlignment();
5388 unsigned NewAlign = TLI.getDataLayout()->
5389 getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
5391 if (NewAlign <= Align &&
5392 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT)))
5393 return DAG.getLoad(VT, N->getDebugLoc(), LD1->getChain(),
5394 LD1->getBasePtr(), LD1->getPointerInfo(),
5395 false, false, false, Align);
5401 SDValue DAGCombiner::visitBITCAST(SDNode *N) {
5402 SDValue N0 = N->getOperand(0);
5403 EVT VT = N->getValueType(0);
5405 // If the input is a BUILD_VECTOR with all constant elements, fold this now.
5406 // Only do this before legalize, since afterward the target may be depending
5407 // on the bitconvert.
5408 // First check to see if this is all constant.
5410 N0.getOpcode() == ISD::BUILD_VECTOR && N0.getNode()->hasOneUse() &&
5412 bool isSimple = true;
5413 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i)
5414 if (N0.getOperand(i).getOpcode() != ISD::UNDEF &&
5415 N0.getOperand(i).getOpcode() != ISD::Constant &&
5416 N0.getOperand(i).getOpcode() != ISD::ConstantFP) {
5421 EVT DestEltVT = N->getValueType(0).getVectorElementType();
5422 assert(!DestEltVT.isVector() &&
5423 "Element type of vector ValueType must not be vector!");
5425 return ConstantFoldBITCASTofBUILD_VECTOR(N0.getNode(), DestEltVT);
5428 // If the input is a constant, let getNode fold it.
5429 if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
5430 SDValue Res = DAG.getNode(ISD::BITCAST, N->getDebugLoc(), VT, N0);
5431 if (Res.getNode() != N) {
5432 if (!LegalOperations ||
5433 TLI.isOperationLegal(Res.getNode()->getOpcode(), VT))
5436 // Folding it resulted in an illegal node, and it's too late to
5437 // do that. Clean up the old node and forego the transformation.
5438 // Ideally this won't happen very often, because instcombine
5439 // and the earlier dagcombine runs (where illegal nodes are
5440 // permitted) should have folded most of them already.
5441 DAG.DeleteNode(Res.getNode());
5445 // (conv (conv x, t1), t2) -> (conv x, t2)
5446 if (N0.getOpcode() == ISD::BITCAST)
5447 return DAG.getNode(ISD::BITCAST, N->getDebugLoc(), VT,
5450 // fold (conv (load x)) -> (load (conv*)x)
5451 // If the resultant load doesn't need a higher alignment than the original!
5452 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
5453 // Do not change the width of a volatile load.
5454 !cast<LoadSDNode>(N0)->isVolatile() &&
5455 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT))) {
5456 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5457 unsigned Align = TLI.getDataLayout()->
5458 getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
5459 unsigned OrigAlign = LN0->getAlignment();
5461 if (Align <= OrigAlign) {
5462 SDValue Load = DAG.getLoad(VT, N->getDebugLoc(), LN0->getChain(),
5463 LN0->getBasePtr(), LN0->getPointerInfo(),
5464 LN0->isVolatile(), LN0->isNonTemporal(),
5465 LN0->isInvariant(), OrigAlign);
5467 CombineTo(N0.getNode(),
5468 DAG.getNode(ISD::BITCAST, N0.getDebugLoc(),
5469 N0.getValueType(), Load),
5475 // fold (bitconvert (fneg x)) -> (xor (bitconvert x), signbit)
5476 // fold (bitconvert (fabs x)) -> (and (bitconvert x), (not signbit))
5477 // This often reduces constant pool loads.
5478 if (((N0.getOpcode() == ISD::FNEG && !TLI.isFNegFree(VT)) ||
5479 (N0.getOpcode() == ISD::FABS && !TLI.isFAbsFree(VT))) &&
5480 N0.getNode()->hasOneUse() && VT.isInteger() &&
5481 !VT.isVector() && !N0.getValueType().isVector()) {
5482 SDValue NewConv = DAG.getNode(ISD::BITCAST, N0.getDebugLoc(), VT,
5484 AddToWorkList(NewConv.getNode());
5486 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
5487 if (N0.getOpcode() == ISD::FNEG)
5488 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT,
5489 NewConv, DAG.getConstant(SignBit, VT));
5490 assert(N0.getOpcode() == ISD::FABS);
5491 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
5492 NewConv, DAG.getConstant(~SignBit, VT));
5495 // fold (bitconvert (fcopysign cst, x)) ->
5496 // (or (and (bitconvert x), sign), (and cst, (not sign)))
5497 // Note that we don't handle (copysign x, cst) because this can always be
5498 // folded to an fneg or fabs.
5499 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse() &&
5500 isa<ConstantFPSDNode>(N0.getOperand(0)) &&
5501 VT.isInteger() && !VT.isVector()) {
5502 unsigned OrigXWidth = N0.getOperand(1).getValueType().getSizeInBits();
5503 EVT IntXVT = EVT::getIntegerVT(*DAG.getContext(), OrigXWidth);
5504 if (isTypeLegal(IntXVT)) {
5505 SDValue X = DAG.getNode(ISD::BITCAST, N0.getDebugLoc(),
5506 IntXVT, N0.getOperand(1));
5507 AddToWorkList(X.getNode());
5509 // If X has a different width than the result/lhs, sext it or truncate it.
5510 unsigned VTWidth = VT.getSizeInBits();
5511 if (OrigXWidth < VTWidth) {
5512 X = DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, X);
5513 AddToWorkList(X.getNode());
5514 } else if (OrigXWidth > VTWidth) {
5515 // To get the sign bit in the right place, we have to shift it right
5516 // before truncating.
5517 X = DAG.getNode(ISD::SRL, X.getDebugLoc(),
5518 X.getValueType(), X,
5519 DAG.getConstant(OrigXWidth-VTWidth, X.getValueType()));
5520 AddToWorkList(X.getNode());
5521 X = DAG.getNode(ISD::TRUNCATE, X.getDebugLoc(), VT, X);
5522 AddToWorkList(X.getNode());
5525 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
5526 X = DAG.getNode(ISD::AND, X.getDebugLoc(), VT,
5527 X, DAG.getConstant(SignBit, VT));
5528 AddToWorkList(X.getNode());
5530 SDValue Cst = DAG.getNode(ISD::BITCAST, N0.getDebugLoc(),
5531 VT, N0.getOperand(0));
5532 Cst = DAG.getNode(ISD::AND, Cst.getDebugLoc(), VT,
5533 Cst, DAG.getConstant(~SignBit, VT));
5534 AddToWorkList(Cst.getNode());
5536 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, X, Cst);
5540 // bitconvert(build_pair(ld, ld)) -> ld iff load locations are consecutive.
5541 if (N0.getOpcode() == ISD::BUILD_PAIR) {
5542 SDValue CombineLD = CombineConsecutiveLoads(N0.getNode(), VT);
5543 if (CombineLD.getNode())
5550 SDValue DAGCombiner::visitBUILD_PAIR(SDNode *N) {
5551 EVT VT = N->getValueType(0);
5552 return CombineConsecutiveLoads(N, VT);
5555 /// ConstantFoldBITCASTofBUILD_VECTOR - We know that BV is a build_vector
5556 /// node with Constant, ConstantFP or Undef operands. DstEltVT indicates the
5557 /// destination element value type.
5558 SDValue DAGCombiner::
5559 ConstantFoldBITCASTofBUILD_VECTOR(SDNode *BV, EVT DstEltVT) {
5560 EVT SrcEltVT = BV->getValueType(0).getVectorElementType();
5562 // If this is already the right type, we're done.
5563 if (SrcEltVT == DstEltVT) return SDValue(BV, 0);
5565 unsigned SrcBitSize = SrcEltVT.getSizeInBits();
5566 unsigned DstBitSize = DstEltVT.getSizeInBits();
5568 // If this is a conversion of N elements of one type to N elements of another
5569 // type, convert each element. This handles FP<->INT cases.
5570 if (SrcBitSize == DstBitSize) {
5571 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
5572 BV->getValueType(0).getVectorNumElements());
5574 // Due to the FP element handling below calling this routine recursively,
5575 // we can end up with a scalar-to-vector node here.
5576 if (BV->getOpcode() == ISD::SCALAR_TO_VECTOR)
5577 return DAG.getNode(ISD::SCALAR_TO_VECTOR, BV->getDebugLoc(), VT,
5578 DAG.getNode(ISD::BITCAST, BV->getDebugLoc(),
5579 DstEltVT, BV->getOperand(0)));
5581 SmallVector<SDValue, 8> Ops;
5582 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
5583 SDValue Op = BV->getOperand(i);
5584 // If the vector element type is not legal, the BUILD_VECTOR operands
5585 // are promoted and implicitly truncated. Make that explicit here.
5586 if (Op.getValueType() != SrcEltVT)
5587 Op = DAG.getNode(ISD::TRUNCATE, BV->getDebugLoc(), SrcEltVT, Op);
5588 Ops.push_back(DAG.getNode(ISD::BITCAST, BV->getDebugLoc(),
5590 AddToWorkList(Ops.back().getNode());
5592 return DAG.getNode(ISD::BUILD_VECTOR, BV->getDebugLoc(), VT,
5593 &Ops[0], Ops.size());
5596 // Otherwise, we're growing or shrinking the elements. To avoid having to
5597 // handle annoying details of growing/shrinking FP values, we convert them to
5599 if (SrcEltVT.isFloatingPoint()) {
5600 // Convert the input float vector to a int vector where the elements are the
5602 assert((SrcEltVT == MVT::f32 || SrcEltVT == MVT::f64) && "Unknown FP VT!");
5603 EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), SrcEltVT.getSizeInBits());
5604 BV = ConstantFoldBITCASTofBUILD_VECTOR(BV, IntVT).getNode();
5608 // Now we know the input is an integer vector. If the output is a FP type,
5609 // convert to integer first, then to FP of the right size.
5610 if (DstEltVT.isFloatingPoint()) {
5611 assert((DstEltVT == MVT::f32 || DstEltVT == MVT::f64) && "Unknown FP VT!");
5612 EVT TmpVT = EVT::getIntegerVT(*DAG.getContext(), DstEltVT.getSizeInBits());
5613 SDNode *Tmp = ConstantFoldBITCASTofBUILD_VECTOR(BV, TmpVT).getNode();
5615 // Next, convert to FP elements of the same size.
5616 return ConstantFoldBITCASTofBUILD_VECTOR(Tmp, DstEltVT);
5619 // Okay, we know the src/dst types are both integers of differing types.
5620 // Handling growing first.
5621 assert(SrcEltVT.isInteger() && DstEltVT.isInteger());
5622 if (SrcBitSize < DstBitSize) {
5623 unsigned NumInputsPerOutput = DstBitSize/SrcBitSize;
5625 SmallVector<SDValue, 8> Ops;
5626 for (unsigned i = 0, e = BV->getNumOperands(); i != e;
5627 i += NumInputsPerOutput) {
5628 bool isLE = TLI.isLittleEndian();
5629 APInt NewBits = APInt(DstBitSize, 0);
5630 bool EltIsUndef = true;
5631 for (unsigned j = 0; j != NumInputsPerOutput; ++j) {
5632 // Shift the previously computed bits over.
5633 NewBits <<= SrcBitSize;
5634 SDValue Op = BV->getOperand(i+ (isLE ? (NumInputsPerOutput-j-1) : j));
5635 if (Op.getOpcode() == ISD::UNDEF) continue;
5638 NewBits |= cast<ConstantSDNode>(Op)->getAPIntValue().
5639 zextOrTrunc(SrcBitSize).zext(DstBitSize);
5643 Ops.push_back(DAG.getUNDEF(DstEltVT));
5645 Ops.push_back(DAG.getConstant(NewBits, DstEltVT));
5648 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT, Ops.size());
5649 return DAG.getNode(ISD::BUILD_VECTOR, BV->getDebugLoc(), VT,
5650 &Ops[0], Ops.size());
5653 // Finally, this must be the case where we are shrinking elements: each input
5654 // turns into multiple outputs.
5655 bool isS2V = ISD::isScalarToVector(BV);
5656 unsigned NumOutputsPerInput = SrcBitSize/DstBitSize;
5657 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
5658 NumOutputsPerInput*BV->getNumOperands());
5659 SmallVector<SDValue, 8> Ops;
5661 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
5662 if (BV->getOperand(i).getOpcode() == ISD::UNDEF) {
5663 for (unsigned j = 0; j != NumOutputsPerInput; ++j)
5664 Ops.push_back(DAG.getUNDEF(DstEltVT));
5668 APInt OpVal = cast<ConstantSDNode>(BV->getOperand(i))->
5669 getAPIntValue().zextOrTrunc(SrcBitSize);
5671 for (unsigned j = 0; j != NumOutputsPerInput; ++j) {
5672 APInt ThisVal = OpVal.trunc(DstBitSize);
5673 Ops.push_back(DAG.getConstant(ThisVal, DstEltVT));
5674 if (isS2V && i == 0 && j == 0 && ThisVal.zext(SrcBitSize) == OpVal)
5675 // Simply turn this into a SCALAR_TO_VECTOR of the new type.
5676 return DAG.getNode(ISD::SCALAR_TO_VECTOR, BV->getDebugLoc(), VT,
5678 OpVal = OpVal.lshr(DstBitSize);
5681 // For big endian targets, swap the order of the pieces of each element.
5682 if (TLI.isBigEndian())
5683 std::reverse(Ops.end()-NumOutputsPerInput, Ops.end());
5686 return DAG.getNode(ISD::BUILD_VECTOR, BV->getDebugLoc(), VT,
5687 &Ops[0], Ops.size());
5690 SDValue DAGCombiner::visitFADD(SDNode *N) {
5691 SDValue N0 = N->getOperand(0);
5692 SDValue N1 = N->getOperand(1);
5693 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
5694 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
5695 EVT VT = N->getValueType(0);
5698 if (VT.isVector()) {
5699 SDValue FoldedVOp = SimplifyVBinOp(N);
5700 if (FoldedVOp.getNode()) return FoldedVOp;
5703 // fold (fadd c1, c2) -> c1 + c2
5705 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0, N1);
5706 // canonicalize constant to RHS
5707 if (N0CFP && !N1CFP)
5708 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N1, N0);
5709 // fold (fadd A, 0) -> A
5710 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
5711 N1CFP->getValueAPF().isZero())
5713 // fold (fadd A, (fneg B)) -> (fsub A, B)
5714 if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
5715 isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options) == 2)
5716 return DAG.getNode(ISD::FSUB, N->getDebugLoc(), VT, N0,
5717 GetNegatedExpression(N1, DAG, LegalOperations));
5718 // fold (fadd (fneg A), B) -> (fsub B, A)
5719 if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
5720 isNegatibleForFree(N0, LegalOperations, TLI, &DAG.getTarget().Options) == 2)
5721 return DAG.getNode(ISD::FSUB, N->getDebugLoc(), VT, N1,
5722 GetNegatedExpression(N0, DAG, LegalOperations));
5724 // If allowed, fold (fadd (fadd x, c1), c2) -> (fadd x, (fadd c1, c2))
5725 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
5726 N0.getOpcode() == ISD::FADD && N0.getNode()->hasOneUse() &&
5727 isa<ConstantFPSDNode>(N0.getOperand(1)))
5728 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0.getOperand(0),
5729 DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5730 N0.getOperand(1), N1));
5732 // If allow, fold (fadd (fneg x), x) -> 0.0
5733 if (DAG.getTarget().Options.UnsafeFPMath &&
5734 N0.getOpcode() == ISD::FNEG && N0.getOperand(0) == N1) {
5735 return DAG.getConstantFP(0.0, VT);
5738 // If allow, fold (fadd x, (fneg x)) -> 0.0
5739 if (DAG.getTarget().Options.UnsafeFPMath &&
5740 N1.getOpcode() == ISD::FNEG && N1.getOperand(0) == N0) {
5741 return DAG.getConstantFP(0.0, VT);
5744 // In unsafe math mode, we can fold chains of FADD's of the same value
5745 // into multiplications. This transform is not safe in general because
5746 // we are reducing the number of rounding steps.
5747 if (DAG.getTarget().Options.UnsafeFPMath &&
5748 TLI.isOperationLegalOrCustom(ISD::FMUL, VT) &&
5750 if (N0.getOpcode() == ISD::FMUL) {
5751 ConstantFPSDNode *CFP00 = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
5752 ConstantFPSDNode *CFP01 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
5754 // (fadd (fmul c, x), x) -> (fmul c+1, x)
5755 if (CFP00 && !CFP01 && N0.getOperand(1) == N1) {
5756 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5758 DAG.getConstantFP(1.0, VT));
5759 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5763 // (fadd (fmul x, c), x) -> (fmul c+1, x)
5764 if (CFP01 && !CFP00 && N0.getOperand(0) == N1) {
5765 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5767 DAG.getConstantFP(1.0, VT));
5768 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5772 // (fadd (fadd x, x), x) -> (fmul 3.0, x)
5773 if (!CFP00 && !CFP01 && N0.getOperand(0) == N0.getOperand(1) &&
5774 N0.getOperand(0) == N1) {
5775 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5776 N1, DAG.getConstantFP(3.0, VT));
5779 // (fadd (fmul c, x), (fadd x, x)) -> (fmul c+2, x)
5780 if (CFP00 && !CFP01 && N1.getOpcode() == ISD::FADD &&
5781 N1.getOperand(0) == N1.getOperand(1) &&
5782 N0.getOperand(1) == N1.getOperand(0)) {
5783 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5785 DAG.getConstantFP(2.0, VT));
5786 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5787 N0.getOperand(1), NewCFP);
5790 // (fadd (fmul x, c), (fadd x, x)) -> (fmul c+2, x)
5791 if (CFP01 && !CFP00 && N1.getOpcode() == ISD::FADD &&
5792 N1.getOperand(0) == N1.getOperand(1) &&
5793 N0.getOperand(0) == N1.getOperand(0)) {
5794 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5796 DAG.getConstantFP(2.0, VT));
5797 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5798 N0.getOperand(0), NewCFP);
5802 if (N1.getOpcode() == ISD::FMUL) {
5803 ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
5804 ConstantFPSDNode *CFP11 = dyn_cast<ConstantFPSDNode>(N1.getOperand(1));
5806 // (fadd x, (fmul c, x)) -> (fmul c+1, x)
5807 if (CFP10 && !CFP11 && N1.getOperand(1) == N0) {
5808 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5810 DAG.getConstantFP(1.0, VT));
5811 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5815 // (fadd x, (fmul x, c)) -> (fmul c+1, x)
5816 if (CFP11 && !CFP10 && N1.getOperand(0) == N0) {
5817 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5819 DAG.getConstantFP(1.0, VT));
5820 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5824 // (fadd x, (fadd x, x)) -> (fmul 3.0, x)
5825 if (!CFP10 && !CFP11 && N1.getOperand(0) == N1.getOperand(1) &&
5826 N1.getOperand(0) == N0) {
5827 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5828 N0, DAG.getConstantFP(3.0, VT));
5831 // (fadd (fadd x, x), (fmul c, x)) -> (fmul c+2, x)
5832 if (CFP10 && !CFP11 && N1.getOpcode() == ISD::FADD &&
5833 N1.getOperand(0) == N1.getOperand(1) &&
5834 N0.getOperand(1) == N1.getOperand(0)) {
5835 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5837 DAG.getConstantFP(2.0, VT));
5838 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5839 N0.getOperand(1), NewCFP);
5842 // (fadd (fadd x, x), (fmul x, c)) -> (fmul c+2, x)
5843 if (CFP11 && !CFP10 && N1.getOpcode() == ISD::FADD &&
5844 N1.getOperand(0) == N1.getOperand(1) &&
5845 N0.getOperand(0) == N1.getOperand(0)) {
5846 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5848 DAG.getConstantFP(2.0, VT));
5849 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5850 N0.getOperand(0), NewCFP);
5854 // (fadd (fadd x, x), (fadd x, x)) -> (fmul 4.0, x)
5855 if (N0.getOpcode() == ISD::FADD && N1.getOpcode() == ISD::FADD &&
5856 N0.getOperand(0) == N0.getOperand(1) &&
5857 N1.getOperand(0) == N1.getOperand(1) &&
5858 N0.getOperand(0) == N1.getOperand(0)) {
5859 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5861 DAG.getConstantFP(4.0, VT));
5865 // FADD -> FMA combines:
5866 if ((DAG.getTarget().Options.AllowFPOpFusion == FPOpFusion::Fast ||
5867 DAG.getTarget().Options.UnsafeFPMath) &&
5868 DAG.getTarget().getTargetLowering()->isFMAFasterThanMulAndAdd(VT) &&
5869 TLI.isOperationLegalOrCustom(ISD::FMA, VT)) {
5871 // fold (fadd (fmul x, y), z) -> (fma x, y, z)
5872 if (N0.getOpcode() == ISD::FMUL && N0->hasOneUse()) {
5873 return DAG.getNode(ISD::FMA, N->getDebugLoc(), VT,
5874 N0.getOperand(0), N0.getOperand(1), N1);
5877 // fold (fadd x, (fmul y, z)) -> (fma y, z, x)
5878 // Note: Commutes FADD operands.
5879 if (N1.getOpcode() == ISD::FMUL && N1->hasOneUse()) {
5880 return DAG.getNode(ISD::FMA, N->getDebugLoc(), VT,
5881 N1.getOperand(0), N1.getOperand(1), N0);
5888 SDValue DAGCombiner::visitFSUB(SDNode *N) {
5889 SDValue N0 = N->getOperand(0);
5890 SDValue N1 = N->getOperand(1);
5891 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
5892 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
5893 EVT VT = N->getValueType(0);
5894 DebugLoc dl = N->getDebugLoc();
5897 if (VT.isVector()) {
5898 SDValue FoldedVOp = SimplifyVBinOp(N);
5899 if (FoldedVOp.getNode()) return FoldedVOp;
5902 // fold (fsub c1, c2) -> c1-c2
5904 return DAG.getNode(ISD::FSUB, N->getDebugLoc(), VT, N0, N1);
5905 // fold (fsub A, 0) -> A
5906 if (DAG.getTarget().Options.UnsafeFPMath &&
5907 N1CFP && N1CFP->getValueAPF().isZero())
5909 // fold (fsub 0, B) -> -B
5910 if (DAG.getTarget().Options.UnsafeFPMath &&
5911 N0CFP && N0CFP->getValueAPF().isZero()) {
5912 if (isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options))
5913 return GetNegatedExpression(N1, DAG, LegalOperations);
5914 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
5915 return DAG.getNode(ISD::FNEG, dl, VT, N1);
5917 // fold (fsub A, (fneg B)) -> (fadd A, B)
5918 if (isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options))
5919 return DAG.getNode(ISD::FADD, dl, VT, N0,
5920 GetNegatedExpression(N1, DAG, LegalOperations));
5922 // If 'unsafe math' is enabled, fold
5923 // (fsub x, x) -> 0.0 &
5924 // (fsub x, (fadd x, y)) -> (fneg y) &
5925 // (fsub x, (fadd y, x)) -> (fneg y)
5926 if (DAG.getTarget().Options.UnsafeFPMath) {
5928 return DAG.getConstantFP(0.0f, VT);
5930 if (N1.getOpcode() == ISD::FADD) {
5931 SDValue N10 = N1->getOperand(0);
5932 SDValue N11 = N1->getOperand(1);
5934 if (N10 == N0 && isNegatibleForFree(N11, LegalOperations, TLI,
5935 &DAG.getTarget().Options))
5936 return GetNegatedExpression(N11, DAG, LegalOperations);
5937 else if (N11 == N0 && isNegatibleForFree(N10, LegalOperations, TLI,
5938 &DAG.getTarget().Options))
5939 return GetNegatedExpression(N10, DAG, LegalOperations);
5943 // FSUB -> FMA combines:
5944 if ((DAG.getTarget().Options.AllowFPOpFusion == FPOpFusion::Fast ||
5945 DAG.getTarget().Options.UnsafeFPMath) &&
5946 DAG.getTarget().getTargetLowering()->isFMAFasterThanMulAndAdd(VT) &&
5947 TLI.isOperationLegalOrCustom(ISD::FMA, VT)) {
5949 // fold (fsub (fmul x, y), z) -> (fma x, y, (fneg z))
5950 if (N0.getOpcode() == ISD::FMUL && N0->hasOneUse()) {
5951 return DAG.getNode(ISD::FMA, dl, VT,
5952 N0.getOperand(0), N0.getOperand(1),
5953 DAG.getNode(ISD::FNEG, dl, VT, N1));
5956 // fold (fsub x, (fmul y, z)) -> (fma (fneg y), z, x)
5957 // Note: Commutes FSUB operands.
5958 if (N1.getOpcode() == ISD::FMUL && N1->hasOneUse()) {
5959 return DAG.getNode(ISD::FMA, dl, VT,
5960 DAG.getNode(ISD::FNEG, dl, VT,
5962 N1.getOperand(1), N0);
5965 // fold (fsub (-(fmul, x, y)), z) -> (fma (fneg x), y, (fneg z))
5966 if (N0.getOpcode() == ISD::FNEG &&
5967 N0.getOperand(0).getOpcode() == ISD::FMUL &&
5968 N0->hasOneUse() && N0.getOperand(0).hasOneUse()) {
5969 SDValue N00 = N0.getOperand(0).getOperand(0);
5970 SDValue N01 = N0.getOperand(0).getOperand(1);
5971 return DAG.getNode(ISD::FMA, dl, VT,
5972 DAG.getNode(ISD::FNEG, dl, VT, N00), N01,
5973 DAG.getNode(ISD::FNEG, dl, VT, N1));
5980 SDValue DAGCombiner::visitFMUL(SDNode *N) {
5981 SDValue N0 = N->getOperand(0);
5982 SDValue N1 = N->getOperand(1);
5983 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
5984 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
5985 EVT VT = N->getValueType(0);
5986 const TargetLowering &TLI = DAG.getTargetLoweringInfo();
5989 if (VT.isVector()) {
5990 SDValue FoldedVOp = SimplifyVBinOp(N);
5991 if (FoldedVOp.getNode()) return FoldedVOp;
5994 // fold (fmul c1, c2) -> c1*c2
5996 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT, N0, N1);
5997 // canonicalize constant to RHS
5998 if (N0CFP && !N1CFP)
5999 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT, N1, N0);
6000 // fold (fmul A, 0) -> 0
6001 if (DAG.getTarget().Options.UnsafeFPMath &&
6002 N1CFP && N1CFP->getValueAPF().isZero())
6004 // fold (fmul A, 0) -> 0, vector edition.
6005 if (DAG.getTarget().Options.UnsafeFPMath &&
6006 ISD::isBuildVectorAllZeros(N1.getNode()))
6008 // fold (fmul A, 1.0) -> A
6009 if (N1CFP && N1CFP->isExactlyValue(1.0))
6011 // fold (fmul X, 2.0) -> (fadd X, X)
6012 if (N1CFP && N1CFP->isExactlyValue(+2.0))
6013 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0, N0);
6014 // fold (fmul X, -1.0) -> (fneg X)
6015 if (N1CFP && N1CFP->isExactlyValue(-1.0))
6016 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
6017 return DAG.getNode(ISD::FNEG, N->getDebugLoc(), VT, N0);
6019 // fold (fmul (fneg X), (fneg Y)) -> (fmul X, Y)
6020 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI,
6021 &DAG.getTarget().Options)) {
6022 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI,
6023 &DAG.getTarget().Options)) {
6024 // Both can be negated for free, check to see if at least one is cheaper
6026 if (LHSNeg == 2 || RHSNeg == 2)
6027 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
6028 GetNegatedExpression(N0, DAG, LegalOperations),
6029 GetNegatedExpression(N1, DAG, LegalOperations));
6033 // If allowed, fold (fmul (fmul x, c1), c2) -> (fmul x, (fmul c1, c2))
6034 if (DAG.getTarget().Options.UnsafeFPMath &&
6035 N1CFP && N0.getOpcode() == ISD::FMUL &&
6036 N0.getNode()->hasOneUse() && isa<ConstantFPSDNode>(N0.getOperand(1)))
6037 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT, N0.getOperand(0),
6038 DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
6039 N0.getOperand(1), N1));
6044 SDValue DAGCombiner::visitFMA(SDNode *N) {
6045 SDValue N0 = N->getOperand(0);
6046 SDValue N1 = N->getOperand(1);
6047 SDValue N2 = N->getOperand(2);
6048 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6049 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6050 EVT VT = N->getValueType(0);
6051 DebugLoc dl = N->getDebugLoc();
6053 if (DAG.getTarget().Options.UnsafeFPMath) {
6054 if (N0CFP && N0CFP->isZero())
6056 if (N1CFP && N1CFP->isZero())
6059 if (N0CFP && N0CFP->isExactlyValue(1.0))
6060 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N1, N2);
6061 if (N1CFP && N1CFP->isExactlyValue(1.0))
6062 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0, N2);
6064 // Canonicalize (fma c, x, y) -> (fma x, c, y)
6065 if (N0CFP && !N1CFP)
6066 return DAG.getNode(ISD::FMA, N->getDebugLoc(), VT, N1, N0, N2);
6068 // (fma x, c1, (fmul x, c2)) -> (fmul x, c1+c2)
6069 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
6070 N2.getOpcode() == ISD::FMUL &&
6071 N0 == N2.getOperand(0) &&
6072 N2.getOperand(1).getOpcode() == ISD::ConstantFP) {
6073 return DAG.getNode(ISD::FMUL, dl, VT, N0,
6074 DAG.getNode(ISD::FADD, dl, VT, N1, N2.getOperand(1)));
6078 // (fma (fmul x, c1), c2, y) -> (fma x, c1*c2, y)
6079 if (DAG.getTarget().Options.UnsafeFPMath &&
6080 N0.getOpcode() == ISD::FMUL && N1CFP &&
6081 N0.getOperand(1).getOpcode() == ISD::ConstantFP) {
6082 return DAG.getNode(ISD::FMA, dl, VT,
6084 DAG.getNode(ISD::FMUL, dl, VT, N1, N0.getOperand(1)),
6088 // (fma x, 1, y) -> (fadd x, y)
6089 // (fma x, -1, y) -> (fadd (fneg x), y)
6091 if (N1CFP->isExactlyValue(1.0))
6092 return DAG.getNode(ISD::FADD, dl, VT, N0, N2);
6094 if (N1CFP->isExactlyValue(-1.0) &&
6095 (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))) {
6096 SDValue RHSNeg = DAG.getNode(ISD::FNEG, dl, VT, N0);
6097 AddToWorkList(RHSNeg.getNode());
6098 return DAG.getNode(ISD::FADD, dl, VT, N2, RHSNeg);
6102 // (fma x, c, x) -> (fmul x, (c+1))
6103 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP && N0 == N2) {
6104 return DAG.getNode(ISD::FMUL, dl, VT,
6106 DAG.getNode(ISD::FADD, dl, VT,
6107 N1, DAG.getConstantFP(1.0, VT)));
6110 // (fma x, c, (fneg x)) -> (fmul x, (c-1))
6111 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
6112 N2.getOpcode() == ISD::FNEG && N2.getOperand(0) == N0) {
6113 return DAG.getNode(ISD::FMUL, dl, VT,
6115 DAG.getNode(ISD::FADD, dl, VT,
6116 N1, DAG.getConstantFP(-1.0, VT)));
6123 SDValue DAGCombiner::visitFDIV(SDNode *N) {
6124 SDValue N0 = N->getOperand(0);
6125 SDValue N1 = N->getOperand(1);
6126 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6127 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6128 EVT VT = N->getValueType(0);
6129 const TargetLowering &TLI = DAG.getTargetLoweringInfo();
6132 if (VT.isVector()) {
6133 SDValue FoldedVOp = SimplifyVBinOp(N);
6134 if (FoldedVOp.getNode()) return FoldedVOp;
6137 // fold (fdiv c1, c2) -> c1/c2
6139 return DAG.getNode(ISD::FDIV, N->getDebugLoc(), VT, N0, N1);
6141 // fold (fdiv X, c2) -> fmul X, 1/c2 if losing precision is acceptable.
6142 if (N1CFP && DAG.getTarget().Options.UnsafeFPMath) {
6143 // Compute the reciprocal 1.0 / c2.
6144 APFloat N1APF = N1CFP->getValueAPF();
6145 APFloat Recip(N1APF.getSemantics(), 1); // 1.0
6146 APFloat::opStatus st = Recip.divide(N1APF, APFloat::rmNearestTiesToEven);
6147 // Only do the transform if the reciprocal is a legal fp immediate that
6148 // isn't too nasty (eg NaN, denormal, ...).
6149 if ((st == APFloat::opOK || st == APFloat::opInexact) && // Not too nasty
6150 (!LegalOperations ||
6151 // FIXME: custom lowering of ConstantFP might fail (see e.g. ARM
6152 // backend)... we should handle this gracefully after Legalize.
6153 // TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT) ||
6154 TLI.isOperationLegal(llvm::ISD::ConstantFP, VT) ||
6155 TLI.isFPImmLegal(Recip, VT)))
6156 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT, N0,
6157 DAG.getConstantFP(Recip, VT));
6160 // (fdiv (fneg X), (fneg Y)) -> (fdiv X, Y)
6161 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI,
6162 &DAG.getTarget().Options)) {
6163 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI,
6164 &DAG.getTarget().Options)) {
6165 // Both can be negated for free, check to see if at least one is cheaper
6167 if (LHSNeg == 2 || RHSNeg == 2)
6168 return DAG.getNode(ISD::FDIV, N->getDebugLoc(), VT,
6169 GetNegatedExpression(N0, DAG, LegalOperations),
6170 GetNegatedExpression(N1, DAG, LegalOperations));
6177 SDValue DAGCombiner::visitFREM(SDNode *N) {
6178 SDValue N0 = N->getOperand(0);
6179 SDValue N1 = N->getOperand(1);
6180 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6181 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6182 EVT VT = N->getValueType(0);
6184 // fold (frem c1, c2) -> fmod(c1,c2)
6186 return DAG.getNode(ISD::FREM, N->getDebugLoc(), VT, N0, N1);
6191 SDValue DAGCombiner::visitFCOPYSIGN(SDNode *N) {
6192 SDValue N0 = N->getOperand(0);
6193 SDValue N1 = N->getOperand(1);
6194 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6195 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6196 EVT VT = N->getValueType(0);
6198 if (N0CFP && N1CFP) // Constant fold
6199 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT, N0, N1);
6202 const APFloat& V = N1CFP->getValueAPF();
6203 // copysign(x, c1) -> fabs(x) iff ispos(c1)
6204 // copysign(x, c1) -> fneg(fabs(x)) iff isneg(c1)
6205 if (!V.isNegative()) {
6206 if (!LegalOperations || TLI.isOperationLegal(ISD::FABS, VT))
6207 return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0);
6209 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
6210 return DAG.getNode(ISD::FNEG, N->getDebugLoc(), VT,
6211 DAG.getNode(ISD::FABS, N0.getDebugLoc(), VT, N0));
6215 // copysign(fabs(x), y) -> copysign(x, y)
6216 // copysign(fneg(x), y) -> copysign(x, y)
6217 // copysign(copysign(x,z), y) -> copysign(x, y)
6218 if (N0.getOpcode() == ISD::FABS || N0.getOpcode() == ISD::FNEG ||
6219 N0.getOpcode() == ISD::FCOPYSIGN)
6220 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT,
6221 N0.getOperand(0), N1);
6223 // copysign(x, abs(y)) -> abs(x)
6224 if (N1.getOpcode() == ISD::FABS)
6225 return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0);
6227 // copysign(x, copysign(y,z)) -> copysign(x, z)
6228 if (N1.getOpcode() == ISD::FCOPYSIGN)
6229 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT,
6230 N0, N1.getOperand(1));
6232 // copysign(x, fp_extend(y)) -> copysign(x, y)
6233 // copysign(x, fp_round(y)) -> copysign(x, y)
6234 if (N1.getOpcode() == ISD::FP_EXTEND || N1.getOpcode() == ISD::FP_ROUND)
6235 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT,
6236 N0, N1.getOperand(0));
6241 SDValue DAGCombiner::visitSINT_TO_FP(SDNode *N) {
6242 SDValue N0 = N->getOperand(0);
6243 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
6244 EVT VT = N->getValueType(0);
6245 EVT OpVT = N0.getValueType();
6247 // fold (sint_to_fp c1) -> c1fp
6249 // ...but only if the target supports immediate floating-point values
6250 (!LegalOperations ||
6251 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT)))
6252 return DAG.getNode(ISD::SINT_TO_FP, N->getDebugLoc(), VT, N0);
6254 // If the input is a legal type, and SINT_TO_FP is not legal on this target,
6255 // but UINT_TO_FP is legal on this target, try to convert.
6256 if (!TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT) &&
6257 TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT)) {
6258 // If the sign bit is known to be zero, we can change this to UINT_TO_FP.
6259 if (DAG.SignBitIsZero(N0))
6260 return DAG.getNode(ISD::UINT_TO_FP, N->getDebugLoc(), VT, N0);
6263 // The next optimizations are desireable only if SELECT_CC can be lowered.
6264 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
6265 // having to say they don't support SELECT_CC on every type the DAG knows
6266 // about, since there is no way to mark an opcode illegal at all value types
6267 // (See also visitSELECT)
6268 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other)) {
6269 // fold (sint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
6270 if (N0.getOpcode() == ISD::SETCC && N0.getValueType() == MVT::i1 &&
6272 (!LegalOperations ||
6273 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
6275 { N0.getOperand(0), N0.getOperand(1),
6276 DAG.getConstantFP(-1.0, VT) , DAG.getConstantFP(0.0, VT),
6278 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT, Ops, 5);
6281 // fold (sint_to_fp (zext (setcc x, y, cc))) ->
6282 // (select_cc x, y, 1.0, 0.0,, cc)
6283 if (N0.getOpcode() == ISD::ZERO_EXTEND &&
6284 N0.getOperand(0).getOpcode() == ISD::SETCC &&!VT.isVector() &&
6285 (!LegalOperations ||
6286 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
6288 { N0.getOperand(0).getOperand(0), N0.getOperand(0).getOperand(1),
6289 DAG.getConstantFP(1.0, VT) , DAG.getConstantFP(0.0, VT),
6290 N0.getOperand(0).getOperand(2) };
6291 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT, Ops, 5);
6298 SDValue DAGCombiner::visitUINT_TO_FP(SDNode *N) {
6299 SDValue N0 = N->getOperand(0);
6300 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
6301 EVT VT = N->getValueType(0);
6302 EVT OpVT = N0.getValueType();
6304 // fold (uint_to_fp c1) -> c1fp
6306 // ...but only if the target supports immediate floating-point values
6307 (!LegalOperations ||
6308 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT)))
6309 return DAG.getNode(ISD::UINT_TO_FP, N->getDebugLoc(), VT, N0);
6311 // If the input is a legal type, and UINT_TO_FP is not legal on this target,
6312 // but SINT_TO_FP is legal on this target, try to convert.
6313 if (!TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT) &&
6314 TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT)) {
6315 // If the sign bit is known to be zero, we can change this to SINT_TO_FP.
6316 if (DAG.SignBitIsZero(N0))
6317 return DAG.getNode(ISD::SINT_TO_FP, N->getDebugLoc(), VT, N0);
6320 // The next optimizations are desireable only if SELECT_CC can be lowered.
6321 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
6322 // having to say they don't support SELECT_CC on every type the DAG knows
6323 // about, since there is no way to mark an opcode illegal at all value types
6324 // (See also visitSELECT)
6325 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other)) {
6326 // fold (uint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
6328 if (N0.getOpcode() == ISD::SETCC && !VT.isVector() &&
6329 (!LegalOperations ||
6330 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
6332 { N0.getOperand(0), N0.getOperand(1),
6333 DAG.getConstantFP(1.0, VT), DAG.getConstantFP(0.0, VT),
6335 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT, Ops, 5);
6342 SDValue DAGCombiner::visitFP_TO_SINT(SDNode *N) {
6343 SDValue N0 = N->getOperand(0);
6344 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6345 EVT VT = N->getValueType(0);
6347 // fold (fp_to_sint c1fp) -> c1
6349 return DAG.getNode(ISD::FP_TO_SINT, N->getDebugLoc(), VT, N0);
6354 SDValue DAGCombiner::visitFP_TO_UINT(SDNode *N) {
6355 SDValue N0 = N->getOperand(0);
6356 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6357 EVT VT = N->getValueType(0);
6359 // fold (fp_to_uint c1fp) -> c1
6361 return DAG.getNode(ISD::FP_TO_UINT, N->getDebugLoc(), VT, N0);
6366 SDValue DAGCombiner::visitFP_ROUND(SDNode *N) {
6367 SDValue N0 = N->getOperand(0);
6368 SDValue N1 = N->getOperand(1);
6369 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6370 EVT VT = N->getValueType(0);
6372 // fold (fp_round c1fp) -> c1fp
6374 return DAG.getNode(ISD::FP_ROUND, N->getDebugLoc(), VT, N0, N1);
6376 // fold (fp_round (fp_extend x)) -> x
6377 if (N0.getOpcode() == ISD::FP_EXTEND && VT == N0.getOperand(0).getValueType())
6378 return N0.getOperand(0);
6380 // fold (fp_round (fp_round x)) -> (fp_round x)
6381 if (N0.getOpcode() == ISD::FP_ROUND) {
6382 // This is a value preserving truncation if both round's are.
6383 bool IsTrunc = N->getConstantOperandVal(1) == 1 &&
6384 N0.getNode()->getConstantOperandVal(1) == 1;
6385 return DAG.getNode(ISD::FP_ROUND, N->getDebugLoc(), VT, N0.getOperand(0),
6386 DAG.getIntPtrConstant(IsTrunc));
6389 // fold (fp_round (copysign X, Y)) -> (copysign (fp_round X), Y)
6390 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse()) {
6391 SDValue Tmp = DAG.getNode(ISD::FP_ROUND, N0.getDebugLoc(), VT,
6392 N0.getOperand(0), N1);
6393 AddToWorkList(Tmp.getNode());
6394 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT,
6395 Tmp, N0.getOperand(1));
6401 SDValue DAGCombiner::visitFP_ROUND_INREG(SDNode *N) {
6402 SDValue N0 = N->getOperand(0);
6403 EVT VT = N->getValueType(0);
6404 EVT EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
6405 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6407 // fold (fp_round_inreg c1fp) -> c1fp
6408 if (N0CFP && isTypeLegal(EVT)) {
6409 SDValue Round = DAG.getConstantFP(*N0CFP->getConstantFPValue(), EVT);
6410 return DAG.getNode(ISD::FP_EXTEND, N->getDebugLoc(), VT, Round);
6416 SDValue DAGCombiner::visitFP_EXTEND(SDNode *N) {
6417 SDValue N0 = N->getOperand(0);
6418 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6419 EVT VT = N->getValueType(0);
6421 // If this is fp_round(fpextend), don't fold it, allow ourselves to be folded.
6422 if (N->hasOneUse() &&
6423 N->use_begin()->getOpcode() == ISD::FP_ROUND)
6426 // fold (fp_extend c1fp) -> c1fp
6428 return DAG.getNode(ISD::FP_EXTEND, N->getDebugLoc(), VT, N0);
6430 // Turn fp_extend(fp_round(X, 1)) -> x since the fp_round doesn't affect the
6432 if (N0.getOpcode() == ISD::FP_ROUND
6433 && N0.getNode()->getConstantOperandVal(1) == 1) {
6434 SDValue In = N0.getOperand(0);
6435 if (In.getValueType() == VT) return In;
6436 if (VT.bitsLT(In.getValueType()))
6437 return DAG.getNode(ISD::FP_ROUND, N->getDebugLoc(), VT,
6438 In, N0.getOperand(1));
6439 return DAG.getNode(ISD::FP_EXTEND, N->getDebugLoc(), VT, In);
6442 // fold (fpext (load x)) -> (fpext (fptrunc (extload x)))
6443 if (ISD::isNON_EXTLoad(N0.getNode()) && N0.hasOneUse() &&
6444 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
6445 TLI.isLoadExtLegal(ISD::EXTLOAD, N0.getValueType()))) {
6446 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6447 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, N->getDebugLoc(), VT,
6449 LN0->getBasePtr(), LN0->getPointerInfo(),
6451 LN0->isVolatile(), LN0->isNonTemporal(),
6452 LN0->getAlignment());
6453 CombineTo(N, ExtLoad);
6454 CombineTo(N0.getNode(),
6455 DAG.getNode(ISD::FP_ROUND, N0.getDebugLoc(),
6456 N0.getValueType(), ExtLoad, DAG.getIntPtrConstant(1)),
6457 ExtLoad.getValue(1));
6458 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6464 SDValue DAGCombiner::visitFNEG(SDNode *N) {
6465 SDValue N0 = N->getOperand(0);
6466 EVT VT = N->getValueType(0);
6468 if (VT.isVector()) {
6469 SDValue FoldedVOp = SimplifyVUnaryOp(N);
6470 if (FoldedVOp.getNode()) return FoldedVOp;
6473 if (isNegatibleForFree(N0, LegalOperations, DAG.getTargetLoweringInfo(),
6474 &DAG.getTarget().Options))
6475 return GetNegatedExpression(N0, DAG, LegalOperations);
6477 // Transform fneg(bitconvert(x)) -> bitconvert(x^sign) to avoid loading
6478 // constant pool values.
6479 if (!TLI.isFNegFree(VT) && N0.getOpcode() == ISD::BITCAST &&
6481 N0.getNode()->hasOneUse() &&
6482 N0.getOperand(0).getValueType().isInteger()) {
6483 SDValue Int = N0.getOperand(0);
6484 EVT IntVT = Int.getValueType();
6485 if (IntVT.isInteger() && !IntVT.isVector()) {
6486 Int = DAG.getNode(ISD::XOR, N0.getDebugLoc(), IntVT, Int,
6487 DAG.getConstant(APInt::getSignBit(IntVT.getSizeInBits()), IntVT));
6488 AddToWorkList(Int.getNode());
6489 return DAG.getNode(ISD::BITCAST, N->getDebugLoc(),
6494 // (fneg (fmul c, x)) -> (fmul -c, x)
6495 if (N0.getOpcode() == ISD::FMUL) {
6496 ConstantFPSDNode *CFP1 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
6498 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
6500 DAG.getNode(ISD::FNEG, N->getDebugLoc(), VT,
6508 SDValue DAGCombiner::visitFCEIL(SDNode *N) {
6509 SDValue N0 = N->getOperand(0);
6510 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6511 EVT VT = N->getValueType(0);
6513 // fold (fceil c1) -> fceil(c1)
6515 return DAG.getNode(ISD::FCEIL, N->getDebugLoc(), VT, N0);
6520 SDValue DAGCombiner::visitFTRUNC(SDNode *N) {
6521 SDValue N0 = N->getOperand(0);
6522 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6523 EVT VT = N->getValueType(0);
6525 // fold (ftrunc c1) -> ftrunc(c1)
6527 return DAG.getNode(ISD::FTRUNC, N->getDebugLoc(), VT, N0);
6532 SDValue DAGCombiner::visitFFLOOR(SDNode *N) {
6533 SDValue N0 = N->getOperand(0);
6534 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6535 EVT VT = N->getValueType(0);
6537 // fold (ffloor c1) -> ffloor(c1)
6539 return DAG.getNode(ISD::FFLOOR, N->getDebugLoc(), VT, N0);
6544 SDValue DAGCombiner::visitFABS(SDNode *N) {
6545 SDValue N0 = N->getOperand(0);
6546 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6547 EVT VT = N->getValueType(0);
6549 if (VT.isVector()) {
6550 SDValue FoldedVOp = SimplifyVUnaryOp(N);
6551 if (FoldedVOp.getNode()) return FoldedVOp;
6554 // fold (fabs c1) -> fabs(c1)
6556 return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0);
6557 // fold (fabs (fabs x)) -> (fabs x)
6558 if (N0.getOpcode() == ISD::FABS)
6559 return N->getOperand(0);
6560 // fold (fabs (fneg x)) -> (fabs x)
6561 // fold (fabs (fcopysign x, y)) -> (fabs x)
6562 if (N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FCOPYSIGN)
6563 return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0.getOperand(0));
6565 // Transform fabs(bitconvert(x)) -> bitconvert(x&~sign) to avoid loading
6566 // constant pool values.
6567 if (!TLI.isFAbsFree(VT) &&
6568 N0.getOpcode() == ISD::BITCAST && N0.getNode()->hasOneUse() &&
6569 N0.getOperand(0).getValueType().isInteger() &&
6570 !N0.getOperand(0).getValueType().isVector()) {
6571 SDValue Int = N0.getOperand(0);
6572 EVT IntVT = Int.getValueType();
6573 if (IntVT.isInteger() && !IntVT.isVector()) {
6574 Int = DAG.getNode(ISD::AND, N0.getDebugLoc(), IntVT, Int,
6575 DAG.getConstant(~APInt::getSignBit(IntVT.getSizeInBits()), IntVT));
6576 AddToWorkList(Int.getNode());
6577 return DAG.getNode(ISD::BITCAST, N->getDebugLoc(),
6578 N->getValueType(0), Int);
6585 SDValue DAGCombiner::visitBRCOND(SDNode *N) {
6586 SDValue Chain = N->getOperand(0);
6587 SDValue N1 = N->getOperand(1);
6588 SDValue N2 = N->getOperand(2);
6590 // If N is a constant we could fold this into a fallthrough or unconditional
6591 // branch. However that doesn't happen very often in normal code, because
6592 // Instcombine/SimplifyCFG should have handled the available opportunities.
6593 // If we did this folding here, it would be necessary to update the
6594 // MachineBasicBlock CFG, which is awkward.
6596 // fold a brcond with a setcc condition into a BR_CC node if BR_CC is legal
6598 if (N1.getOpcode() == ISD::SETCC &&
6599 TLI.isOperationLegalOrCustom(ISD::BR_CC, MVT::Other)) {
6600 return DAG.getNode(ISD::BR_CC, N->getDebugLoc(), MVT::Other,
6601 Chain, N1.getOperand(2),
6602 N1.getOperand(0), N1.getOperand(1), N2);
6605 if ((N1.hasOneUse() && N1.getOpcode() == ISD::SRL) ||
6606 ((N1.getOpcode() == ISD::TRUNCATE && N1.hasOneUse()) &&
6607 (N1.getOperand(0).hasOneUse() &&
6608 N1.getOperand(0).getOpcode() == ISD::SRL))) {
6610 if (N1.getOpcode() == ISD::TRUNCATE) {
6611 // Look pass the truncate.
6612 Trunc = N1.getNode();
6613 N1 = N1.getOperand(0);
6616 // Match this pattern so that we can generate simpler code:
6619 // %b = and i32 %a, 2
6620 // %c = srl i32 %b, 1
6621 // brcond i32 %c ...
6626 // %b = and i32 %a, 2
6627 // %c = setcc eq %b, 0
6630 // This applies only when the AND constant value has one bit set and the
6631 // SRL constant is equal to the log2 of the AND constant. The back-end is
6632 // smart enough to convert the result into a TEST/JMP sequence.
6633 SDValue Op0 = N1.getOperand(0);
6634 SDValue Op1 = N1.getOperand(1);
6636 if (Op0.getOpcode() == ISD::AND &&
6637 Op1.getOpcode() == ISD::Constant) {
6638 SDValue AndOp1 = Op0.getOperand(1);
6640 if (AndOp1.getOpcode() == ISD::Constant) {
6641 const APInt &AndConst = cast<ConstantSDNode>(AndOp1)->getAPIntValue();
6643 if (AndConst.isPowerOf2() &&
6644 cast<ConstantSDNode>(Op1)->getAPIntValue()==AndConst.logBase2()) {
6646 DAG.getSetCC(N->getDebugLoc(),
6647 TLI.getSetCCResultType(Op0.getValueType()),
6648 Op0, DAG.getConstant(0, Op0.getValueType()),
6651 SDValue NewBRCond = DAG.getNode(ISD::BRCOND, N->getDebugLoc(),
6652 MVT::Other, Chain, SetCC, N2);
6653 // Don't add the new BRCond into the worklist or else SimplifySelectCC
6654 // will convert it back to (X & C1) >> C2.
6655 CombineTo(N, NewBRCond, false);
6656 // Truncate is dead.
6658 removeFromWorkList(Trunc);
6659 DAG.DeleteNode(Trunc);
6661 // Replace the uses of SRL with SETCC
6662 WorkListRemover DeadNodes(*this);
6663 DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
6664 removeFromWorkList(N1.getNode());
6665 DAG.DeleteNode(N1.getNode());
6666 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6672 // Restore N1 if the above transformation doesn't match.
6673 N1 = N->getOperand(1);
6676 // Transform br(xor(x, y)) -> br(x != y)
6677 // Transform br(xor(xor(x,y), 1)) -> br (x == y)
6678 if (N1.hasOneUse() && N1.getOpcode() == ISD::XOR) {
6679 SDNode *TheXor = N1.getNode();
6680 SDValue Op0 = TheXor->getOperand(0);
6681 SDValue Op1 = TheXor->getOperand(1);
6682 if (Op0.getOpcode() == Op1.getOpcode()) {
6683 // Avoid missing important xor optimizations.
6684 SDValue Tmp = visitXOR(TheXor);
6685 if (Tmp.getNode() && Tmp.getNode() != TheXor) {
6686 DEBUG(dbgs() << "\nReplacing.8 ";
6688 dbgs() << "\nWith: ";
6689 Tmp.getNode()->dump(&DAG);
6691 WorkListRemover DeadNodes(*this);
6692 DAG.ReplaceAllUsesOfValueWith(N1, Tmp);
6693 removeFromWorkList(TheXor);
6694 DAG.DeleteNode(TheXor);
6695 return DAG.getNode(ISD::BRCOND, N->getDebugLoc(),
6696 MVT::Other, Chain, Tmp, N2);
6700 if (Op0.getOpcode() != ISD::SETCC && Op1.getOpcode() != ISD::SETCC) {
6702 if (ConstantSDNode *RHSCI = dyn_cast<ConstantSDNode>(Op0))
6703 if (RHSCI->getAPIntValue() == 1 && Op0.hasOneUse() &&
6704 Op0.getOpcode() == ISD::XOR) {
6705 TheXor = Op0.getNode();
6709 EVT SetCCVT = N1.getValueType();
6711 SetCCVT = TLI.getSetCCResultType(SetCCVT);
6712 SDValue SetCC = DAG.getSetCC(TheXor->getDebugLoc(),
6715 Equal ? ISD::SETEQ : ISD::SETNE);
6716 // Replace the uses of XOR with SETCC
6717 WorkListRemover DeadNodes(*this);
6718 DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
6719 removeFromWorkList(N1.getNode());
6720 DAG.DeleteNode(N1.getNode());
6721 return DAG.getNode(ISD::BRCOND, N->getDebugLoc(),
6722 MVT::Other, Chain, SetCC, N2);
6729 // Operand List for BR_CC: Chain, CondCC, CondLHS, CondRHS, DestBB.
6731 SDValue DAGCombiner::visitBR_CC(SDNode *N) {
6732 CondCodeSDNode *CC = cast<CondCodeSDNode>(N->getOperand(1));
6733 SDValue CondLHS = N->getOperand(2), CondRHS = N->getOperand(3);
6735 // If N is a constant we could fold this into a fallthrough or unconditional
6736 // branch. However that doesn't happen very often in normal code, because
6737 // Instcombine/SimplifyCFG should have handled the available opportunities.
6738 // If we did this folding here, it would be necessary to update the
6739 // MachineBasicBlock CFG, which is awkward.
6741 // Use SimplifySetCC to simplify SETCC's.
6742 SDValue Simp = SimplifySetCC(TLI.getSetCCResultType(CondLHS.getValueType()),
6743 CondLHS, CondRHS, CC->get(), N->getDebugLoc(),
6745 if (Simp.getNode()) AddToWorkList(Simp.getNode());
6747 // fold to a simpler setcc
6748 if (Simp.getNode() && Simp.getOpcode() == ISD::SETCC)
6749 return DAG.getNode(ISD::BR_CC, N->getDebugLoc(), MVT::Other,
6750 N->getOperand(0), Simp.getOperand(2),
6751 Simp.getOperand(0), Simp.getOperand(1),
6757 /// canFoldInAddressingMode - Return true if 'Use' is a load or a store that
6758 /// uses N as its base pointer and that N may be folded in the load / store
6759 /// addressing mode.
6760 static bool canFoldInAddressingMode(SDNode *N, SDNode *Use,
6762 const TargetLowering &TLI) {
6764 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Use)) {
6765 if (LD->isIndexed() || LD->getBasePtr().getNode() != N)
6767 VT = Use->getValueType(0);
6768 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(Use)) {
6769 if (ST->isIndexed() || ST->getBasePtr().getNode() != N)
6771 VT = ST->getValue().getValueType();
6776 if (N->getOpcode() == ISD::ADD) {
6777 ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
6780 AM.BaseOffs = Offset->getSExtValue();
6784 } else if (N->getOpcode() == ISD::SUB) {
6785 ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
6788 AM.BaseOffs = -Offset->getSExtValue();
6795 return TLI.isLegalAddressingMode(AM, VT.getTypeForEVT(*DAG.getContext()));
6798 /// CombineToPreIndexedLoadStore - Try turning a load / store into a
6799 /// pre-indexed load / store when the base pointer is an add or subtract
6800 /// and it has other uses besides the load / store. After the
6801 /// transformation, the new indexed load / store has effectively folded
6802 /// the add / subtract in and all of its other uses are redirected to the
6803 /// new load / store.
6804 bool DAGCombiner::CombineToPreIndexedLoadStore(SDNode *N) {
6805 if (Level < AfterLegalizeDAG)
6811 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
6812 if (LD->isIndexed())
6814 VT = LD->getMemoryVT();
6815 if (!TLI.isIndexedLoadLegal(ISD::PRE_INC, VT) &&
6816 !TLI.isIndexedLoadLegal(ISD::PRE_DEC, VT))
6818 Ptr = LD->getBasePtr();
6819 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
6820 if (ST->isIndexed())
6822 VT = ST->getMemoryVT();
6823 if (!TLI.isIndexedStoreLegal(ISD::PRE_INC, VT) &&
6824 !TLI.isIndexedStoreLegal(ISD::PRE_DEC, VT))
6826 Ptr = ST->getBasePtr();
6832 // If the pointer is not an add/sub, or if it doesn't have multiple uses, bail
6833 // out. There is no reason to make this a preinc/predec.
6834 if ((Ptr.getOpcode() != ISD::ADD && Ptr.getOpcode() != ISD::SUB) ||
6835 Ptr.getNode()->hasOneUse())
6838 // Ask the target to do addressing mode selection.
6841 ISD::MemIndexedMode AM = ISD::UNINDEXED;
6842 if (!TLI.getPreIndexedAddressParts(N, BasePtr, Offset, AM, DAG))
6844 // Don't create a indexed load / store with zero offset.
6845 if (isa<ConstantSDNode>(Offset) &&
6846 cast<ConstantSDNode>(Offset)->isNullValue())
6849 // Try turning it into a pre-indexed load / store except when:
6850 // 1) The new base ptr is a frame index.
6851 // 2) If N is a store and the new base ptr is either the same as or is a
6852 // predecessor of the value being stored.
6853 // 3) Another use of old base ptr is a predecessor of N. If ptr is folded
6854 // that would create a cycle.
6855 // 4) All uses are load / store ops that use it as old base ptr.
6857 // Check #1. Preinc'ing a frame index would require copying the stack pointer
6858 // (plus the implicit offset) to a register to preinc anyway.
6859 if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
6864 SDValue Val = cast<StoreSDNode>(N)->getValue();
6865 if (Val == BasePtr || BasePtr.getNode()->isPredecessorOf(Val.getNode()))
6869 // Now check for #3 and #4.
6870 bool RealUse = false;
6872 // Caches for hasPredecessorHelper
6873 SmallPtrSet<const SDNode *, 32> Visited;
6874 SmallVector<const SDNode *, 16> Worklist;
6876 for (SDNode::use_iterator I = Ptr.getNode()->use_begin(),
6877 E = Ptr.getNode()->use_end(); I != E; ++I) {
6881 if (N->hasPredecessorHelper(Use, Visited, Worklist))
6884 // If Ptr may be folded in addressing mode of other use, then it's
6885 // not profitable to do this transformation.
6886 if (!canFoldInAddressingMode(Ptr.getNode(), Use, DAG, TLI))
6895 Result = DAG.getIndexedLoad(SDValue(N,0), N->getDebugLoc(),
6896 BasePtr, Offset, AM);
6898 Result = DAG.getIndexedStore(SDValue(N,0), N->getDebugLoc(),
6899 BasePtr, Offset, AM);
6902 DEBUG(dbgs() << "\nReplacing.4 ";
6904 dbgs() << "\nWith: ";
6905 Result.getNode()->dump(&DAG);
6907 WorkListRemover DeadNodes(*this);
6909 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
6910 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
6912 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
6915 // Finally, since the node is now dead, remove it from the graph.
6918 // Replace the uses of Ptr with uses of the updated base value.
6919 DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0));
6920 removeFromWorkList(Ptr.getNode());
6921 DAG.DeleteNode(Ptr.getNode());
6926 /// CombineToPostIndexedLoadStore - Try to combine a load / store with a
6927 /// add / sub of the base pointer node into a post-indexed load / store.
6928 /// The transformation folded the add / subtract into the new indexed
6929 /// load / store effectively and all of its uses are redirected to the
6930 /// new load / store.
6931 bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
6932 if (Level < AfterLegalizeDAG)
6938 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
6939 if (LD->isIndexed())
6941 VT = LD->getMemoryVT();
6942 if (!TLI.isIndexedLoadLegal(ISD::POST_INC, VT) &&
6943 !TLI.isIndexedLoadLegal(ISD::POST_DEC, VT))
6945 Ptr = LD->getBasePtr();
6946 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
6947 if (ST->isIndexed())
6949 VT = ST->getMemoryVT();
6950 if (!TLI.isIndexedStoreLegal(ISD::POST_INC, VT) &&
6951 !TLI.isIndexedStoreLegal(ISD::POST_DEC, VT))
6953 Ptr = ST->getBasePtr();
6959 if (Ptr.getNode()->hasOneUse())
6962 for (SDNode::use_iterator I = Ptr.getNode()->use_begin(),
6963 E = Ptr.getNode()->use_end(); I != E; ++I) {
6966 (Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB))
6971 ISD::MemIndexedMode AM = ISD::UNINDEXED;
6972 if (TLI.getPostIndexedAddressParts(N, Op, BasePtr, Offset, AM, DAG)) {
6973 // Don't create a indexed load / store with zero offset.
6974 if (isa<ConstantSDNode>(Offset) &&
6975 cast<ConstantSDNode>(Offset)->isNullValue())
6978 // Try turning it into a post-indexed load / store except when
6979 // 1) All uses are load / store ops that use it as base ptr (and
6980 // it may be folded as addressing mmode).
6981 // 2) Op must be independent of N, i.e. Op is neither a predecessor
6982 // nor a successor of N. Otherwise, if Op is folded that would
6985 if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
6989 bool TryNext = false;
6990 for (SDNode::use_iterator II = BasePtr.getNode()->use_begin(),
6991 EE = BasePtr.getNode()->use_end(); II != EE; ++II) {
6993 if (Use == Ptr.getNode())
6996 // If all the uses are load / store addresses, then don't do the
6998 if (Use->getOpcode() == ISD::ADD || Use->getOpcode() == ISD::SUB){
6999 bool RealUse = false;
7000 for (SDNode::use_iterator III = Use->use_begin(),
7001 EEE = Use->use_end(); III != EEE; ++III) {
7002 SDNode *UseUse = *III;
7003 if (!canFoldInAddressingMode(Use, UseUse, DAG, TLI))
7018 if (!Op->isPredecessorOf(N) && !N->isPredecessorOf(Op)) {
7019 SDValue Result = isLoad
7020 ? DAG.getIndexedLoad(SDValue(N,0), N->getDebugLoc(),
7021 BasePtr, Offset, AM)
7022 : DAG.getIndexedStore(SDValue(N,0), N->getDebugLoc(),
7023 BasePtr, Offset, AM);
7026 DEBUG(dbgs() << "\nReplacing.5 ";
7028 dbgs() << "\nWith: ";
7029 Result.getNode()->dump(&DAG);
7031 WorkListRemover DeadNodes(*this);
7033 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
7034 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
7036 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
7039 // Finally, since the node is now dead, remove it from the graph.
7042 // Replace the uses of Use with uses of the updated base value.
7043 DAG.ReplaceAllUsesOfValueWith(SDValue(Op, 0),
7044 Result.getValue(isLoad ? 1 : 0));
7045 removeFromWorkList(Op);
7055 SDValue DAGCombiner::visitLOAD(SDNode *N) {
7056 LoadSDNode *LD = cast<LoadSDNode>(N);
7057 SDValue Chain = LD->getChain();
7058 SDValue Ptr = LD->getBasePtr();
7060 // If load is not volatile and there are no uses of the loaded value (and
7061 // the updated indexed value in case of indexed loads), change uses of the
7062 // chain value into uses of the chain input (i.e. delete the dead load).
7063 if (!LD->isVolatile()) {
7064 if (N->getValueType(1) == MVT::Other) {
7066 if (!N->hasAnyUseOfValue(0)) {
7067 // It's not safe to use the two value CombineTo variant here. e.g.
7068 // v1, chain2 = load chain1, loc
7069 // v2, chain3 = load chain2, loc
7071 // Now we replace use of chain2 with chain1. This makes the second load
7072 // isomorphic to the one we are deleting, and thus makes this load live.
7073 DEBUG(dbgs() << "\nReplacing.6 ";
7075 dbgs() << "\nWith chain: ";
7076 Chain.getNode()->dump(&DAG);
7078 WorkListRemover DeadNodes(*this);
7079 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain);
7081 if (N->use_empty()) {
7082 removeFromWorkList(N);
7086 return SDValue(N, 0); // Return N so it doesn't get rechecked!
7090 assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?");
7091 if (!N->hasAnyUseOfValue(0) && !N->hasAnyUseOfValue(1)) {
7092 SDValue Undef = DAG.getUNDEF(N->getValueType(0));
7093 DEBUG(dbgs() << "\nReplacing.7 ";
7095 dbgs() << "\nWith: ";
7096 Undef.getNode()->dump(&DAG);
7097 dbgs() << " and 2 other values\n");
7098 WorkListRemover DeadNodes(*this);
7099 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Undef);
7100 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1),
7101 DAG.getUNDEF(N->getValueType(1)));
7102 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 2), Chain);
7103 removeFromWorkList(N);
7105 return SDValue(N, 0); // Return N so it doesn't get rechecked!
7110 // If this load is directly stored, replace the load value with the stored
7112 // TODO: Handle store large -> read small portion.
7113 // TODO: Handle TRUNCSTORE/LOADEXT
7114 if (ISD::isNormalLoad(N) && !LD->isVolatile()) {
7115 if (ISD::isNON_TRUNCStore(Chain.getNode())) {
7116 StoreSDNode *PrevST = cast<StoreSDNode>(Chain);
7117 if (PrevST->getBasePtr() == Ptr &&
7118 PrevST->getValue().getValueType() == N->getValueType(0))
7119 return CombineTo(N, Chain.getOperand(1), Chain);
7123 // Try to infer better alignment information than the load already has.
7124 if (OptLevel != CodeGenOpt::None && LD->isUnindexed()) {
7125 if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
7126 if (Align > LD->getAlignment())
7127 return DAG.getExtLoad(LD->getExtensionType(), N->getDebugLoc(),
7128 LD->getValueType(0),
7129 Chain, Ptr, LD->getPointerInfo(),
7131 LD->isVolatile(), LD->isNonTemporal(), Align);
7136 // Walk up chain skipping non-aliasing memory nodes.
7137 SDValue BetterChain = FindBetterChain(N, Chain);
7139 // If there is a better chain.
7140 if (Chain != BetterChain) {
7143 // Replace the chain to void dependency.
7144 if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
7145 ReplLoad = DAG.getLoad(N->getValueType(0), LD->getDebugLoc(),
7146 BetterChain, Ptr, LD->getPointerInfo(),
7147 LD->isVolatile(), LD->isNonTemporal(),
7148 LD->isInvariant(), LD->getAlignment());
7150 ReplLoad = DAG.getExtLoad(LD->getExtensionType(), LD->getDebugLoc(),
7151 LD->getValueType(0),
7152 BetterChain, Ptr, LD->getPointerInfo(),
7155 LD->isNonTemporal(),
7156 LD->getAlignment());
7159 // Create token factor to keep old chain connected.
7160 SDValue Token = DAG.getNode(ISD::TokenFactor, N->getDebugLoc(),
7161 MVT::Other, Chain, ReplLoad.getValue(1));
7163 // Make sure the new and old chains are cleaned up.
7164 AddToWorkList(Token.getNode());
7166 // Replace uses with load result and token factor. Don't add users
7168 return CombineTo(N, ReplLoad.getValue(0), Token, false);
7172 // Try transforming N to an indexed load.
7173 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
7174 return SDValue(N, 0);
7179 /// CheckForMaskedLoad - Check to see if V is (and load (ptr), imm), where the
7180 /// load is having specific bytes cleared out. If so, return the byte size
7181 /// being masked out and the shift amount.
7182 static std::pair<unsigned, unsigned>
7183 CheckForMaskedLoad(SDValue V, SDValue Ptr, SDValue Chain) {
7184 std::pair<unsigned, unsigned> Result(0, 0);
7186 // Check for the structure we're looking for.
7187 if (V->getOpcode() != ISD::AND ||
7188 !isa<ConstantSDNode>(V->getOperand(1)) ||
7189 !ISD::isNormalLoad(V->getOperand(0).getNode()))
7192 // Check the chain and pointer.
7193 LoadSDNode *LD = cast<LoadSDNode>(V->getOperand(0));
7194 if (LD->getBasePtr() != Ptr) return Result; // Not from same pointer.
7196 // The store should be chained directly to the load or be an operand of a
7198 if (LD == Chain.getNode())
7200 else if (Chain->getOpcode() != ISD::TokenFactor)
7201 return Result; // Fail.
7204 for (unsigned i = 0, e = Chain->getNumOperands(); i != e; ++i)
7205 if (Chain->getOperand(i).getNode() == LD) {
7209 if (!isOk) return Result;
7212 // This only handles simple types.
7213 if (V.getValueType() != MVT::i16 &&
7214 V.getValueType() != MVT::i32 &&
7215 V.getValueType() != MVT::i64)
7218 // Check the constant mask. Invert it so that the bits being masked out are
7219 // 0 and the bits being kept are 1. Use getSExtValue so that leading bits
7220 // follow the sign bit for uniformity.
7221 uint64_t NotMask = ~cast<ConstantSDNode>(V->getOperand(1))->getSExtValue();
7222 unsigned NotMaskLZ = CountLeadingZeros_64(NotMask);
7223 if (NotMaskLZ & 7) return Result; // Must be multiple of a byte.
7224 unsigned NotMaskTZ = CountTrailingZeros_64(NotMask);
7225 if (NotMaskTZ & 7) return Result; // Must be multiple of a byte.
7226 if (NotMaskLZ == 64) return Result; // All zero mask.
7228 // See if we have a continuous run of bits. If so, we have 0*1+0*
7229 if (CountTrailingOnes_64(NotMask >> NotMaskTZ)+NotMaskTZ+NotMaskLZ != 64)
7232 // Adjust NotMaskLZ down to be from the actual size of the int instead of i64.
7233 if (V.getValueType() != MVT::i64 && NotMaskLZ)
7234 NotMaskLZ -= 64-V.getValueSizeInBits();
7236 unsigned MaskedBytes = (V.getValueSizeInBits()-NotMaskLZ-NotMaskTZ)/8;
7237 switch (MaskedBytes) {
7241 default: return Result; // All one mask, or 5-byte mask.
7244 // Verify that the first bit starts at a multiple of mask so that the access
7245 // is aligned the same as the access width.
7246 if (NotMaskTZ && NotMaskTZ/8 % MaskedBytes) return Result;
7248 Result.first = MaskedBytes;
7249 Result.second = NotMaskTZ/8;
7254 /// ShrinkLoadReplaceStoreWithStore - Check to see if IVal is something that
7255 /// provides a value as specified by MaskInfo. If so, replace the specified
7256 /// store with a narrower store of truncated IVal.
7258 ShrinkLoadReplaceStoreWithStore(const std::pair<unsigned, unsigned> &MaskInfo,
7259 SDValue IVal, StoreSDNode *St,
7261 unsigned NumBytes = MaskInfo.first;
7262 unsigned ByteShift = MaskInfo.second;
7263 SelectionDAG &DAG = DC->getDAG();
7265 // Check to see if IVal is all zeros in the part being masked in by the 'or'
7266 // that uses this. If not, this is not a replacement.
7267 APInt Mask = ~APInt::getBitsSet(IVal.getValueSizeInBits(),
7268 ByteShift*8, (ByteShift+NumBytes)*8);
7269 if (!DAG.MaskedValueIsZero(IVal, Mask)) return 0;
7271 // Check that it is legal on the target to do this. It is legal if the new
7272 // VT we're shrinking to (i8/i16/i32) is legal or we're still before type
7274 MVT VT = MVT::getIntegerVT(NumBytes*8);
7275 if (!DC->isTypeLegal(VT))
7278 // Okay, we can do this! Replace the 'St' store with a store of IVal that is
7279 // shifted by ByteShift and truncated down to NumBytes.
7281 IVal = DAG.getNode(ISD::SRL, IVal->getDebugLoc(), IVal.getValueType(), IVal,
7282 DAG.getConstant(ByteShift*8,
7283 DC->getShiftAmountTy(IVal.getValueType())));
7285 // Figure out the offset for the store and the alignment of the access.
7287 unsigned NewAlign = St->getAlignment();
7289 if (DAG.getTargetLoweringInfo().isLittleEndian())
7290 StOffset = ByteShift;
7292 StOffset = IVal.getValueType().getStoreSize() - ByteShift - NumBytes;
7294 SDValue Ptr = St->getBasePtr();
7296 Ptr = DAG.getNode(ISD::ADD, IVal->getDebugLoc(), Ptr.getValueType(),
7297 Ptr, DAG.getConstant(StOffset, Ptr.getValueType()));
7298 NewAlign = MinAlign(NewAlign, StOffset);
7301 // Truncate down to the new size.
7302 IVal = DAG.getNode(ISD::TRUNCATE, IVal->getDebugLoc(), VT, IVal);
7305 return DAG.getStore(St->getChain(), St->getDebugLoc(), IVal, Ptr,
7306 St->getPointerInfo().getWithOffset(StOffset),
7307 false, false, NewAlign).getNode();
7311 /// ReduceLoadOpStoreWidth - Look for sequence of load / op / store where op is
7312 /// one of 'or', 'xor', and 'and' of immediates. If 'op' is only touching some
7313 /// of the loaded bits, try narrowing the load and store if it would end up
7314 /// being a win for performance or code size.
7315 SDValue DAGCombiner::ReduceLoadOpStoreWidth(SDNode *N) {
7316 StoreSDNode *ST = cast<StoreSDNode>(N);
7317 if (ST->isVolatile())
7320 SDValue Chain = ST->getChain();
7321 SDValue Value = ST->getValue();
7322 SDValue Ptr = ST->getBasePtr();
7323 EVT VT = Value.getValueType();
7325 if (ST->isTruncatingStore() || VT.isVector() || !Value.hasOneUse())
7328 unsigned Opc = Value.getOpcode();
7330 // If this is "store (or X, Y), P" and X is "(and (load P), cst)", where cst
7331 // is a byte mask indicating a consecutive number of bytes, check to see if
7332 // Y is known to provide just those bytes. If so, we try to replace the
7333 // load + replace + store sequence with a single (narrower) store, which makes
7335 if (Opc == ISD::OR) {
7336 std::pair<unsigned, unsigned> MaskedLoad;
7337 MaskedLoad = CheckForMaskedLoad(Value.getOperand(0), Ptr, Chain);
7338 if (MaskedLoad.first)
7339 if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
7340 Value.getOperand(1), ST,this))
7341 return SDValue(NewST, 0);
7343 // Or is commutative, so try swapping X and Y.
7344 MaskedLoad = CheckForMaskedLoad(Value.getOperand(1), Ptr, Chain);
7345 if (MaskedLoad.first)
7346 if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
7347 Value.getOperand(0), ST,this))
7348 return SDValue(NewST, 0);
7351 if ((Opc != ISD::OR && Opc != ISD::XOR && Opc != ISD::AND) ||
7352 Value.getOperand(1).getOpcode() != ISD::Constant)
7355 SDValue N0 = Value.getOperand(0);
7356 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
7357 Chain == SDValue(N0.getNode(), 1)) {
7358 LoadSDNode *LD = cast<LoadSDNode>(N0);
7359 if (LD->getBasePtr() != Ptr ||
7360 LD->getPointerInfo().getAddrSpace() !=
7361 ST->getPointerInfo().getAddrSpace())
7364 // Find the type to narrow it the load / op / store to.
7365 SDValue N1 = Value.getOperand(1);
7366 unsigned BitWidth = N1.getValueSizeInBits();
7367 APInt Imm = cast<ConstantSDNode>(N1)->getAPIntValue();
7368 if (Opc == ISD::AND)
7369 Imm ^= APInt::getAllOnesValue(BitWidth);
7370 if (Imm == 0 || Imm.isAllOnesValue())
7372 unsigned ShAmt = Imm.countTrailingZeros();
7373 unsigned MSB = BitWidth - Imm.countLeadingZeros() - 1;
7374 unsigned NewBW = NextPowerOf2(MSB - ShAmt);
7375 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
7376 while (NewBW < BitWidth &&
7377 !(TLI.isOperationLegalOrCustom(Opc, NewVT) &&
7378 TLI.isNarrowingProfitable(VT, NewVT))) {
7379 NewBW = NextPowerOf2(NewBW);
7380 NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
7382 if (NewBW >= BitWidth)
7385 // If the lsb changed does not start at the type bitwidth boundary,
7386 // start at the previous one.
7388 ShAmt = (((ShAmt + NewBW - 1) / NewBW) * NewBW) - NewBW;
7389 APInt Mask = APInt::getBitsSet(BitWidth, ShAmt, ShAmt + NewBW);
7390 if ((Imm & Mask) == Imm) {
7391 APInt NewImm = (Imm & Mask).lshr(ShAmt).trunc(NewBW);
7392 if (Opc == ISD::AND)
7393 NewImm ^= APInt::getAllOnesValue(NewBW);
7394 uint64_t PtrOff = ShAmt / 8;
7395 // For big endian targets, we need to adjust the offset to the pointer to
7396 // load the correct bytes.
7397 if (TLI.isBigEndian())
7398 PtrOff = (BitWidth + 7 - NewBW) / 8 - PtrOff;
7400 unsigned NewAlign = MinAlign(LD->getAlignment(), PtrOff);
7401 Type *NewVTTy = NewVT.getTypeForEVT(*DAG.getContext());
7402 if (NewAlign < TLI.getDataLayout()->getABITypeAlignment(NewVTTy))
7405 SDValue NewPtr = DAG.getNode(ISD::ADD, LD->getDebugLoc(),
7406 Ptr.getValueType(), Ptr,
7407 DAG.getConstant(PtrOff, Ptr.getValueType()));
7408 SDValue NewLD = DAG.getLoad(NewVT, N0.getDebugLoc(),
7409 LD->getChain(), NewPtr,
7410 LD->getPointerInfo().getWithOffset(PtrOff),
7411 LD->isVolatile(), LD->isNonTemporal(),
7412 LD->isInvariant(), NewAlign);
7413 SDValue NewVal = DAG.getNode(Opc, Value.getDebugLoc(), NewVT, NewLD,
7414 DAG.getConstant(NewImm, NewVT));
7415 SDValue NewST = DAG.getStore(Chain, N->getDebugLoc(),
7417 ST->getPointerInfo().getWithOffset(PtrOff),
7418 false, false, NewAlign);
7420 AddToWorkList(NewPtr.getNode());
7421 AddToWorkList(NewLD.getNode());
7422 AddToWorkList(NewVal.getNode());
7423 WorkListRemover DeadNodes(*this);
7424 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), NewLD.getValue(1));
7433 /// TransformFPLoadStorePair - For a given floating point load / store pair,
7434 /// if the load value isn't used by any other operations, then consider
7435 /// transforming the pair to integer load / store operations if the target
7436 /// deems the transformation profitable.
7437 SDValue DAGCombiner::TransformFPLoadStorePair(SDNode *N) {
7438 StoreSDNode *ST = cast<StoreSDNode>(N);
7439 SDValue Chain = ST->getChain();
7440 SDValue Value = ST->getValue();
7441 if (ISD::isNormalStore(ST) && ISD::isNormalLoad(Value.getNode()) &&
7442 Value.hasOneUse() &&
7443 Chain == SDValue(Value.getNode(), 1)) {
7444 LoadSDNode *LD = cast<LoadSDNode>(Value);
7445 EVT VT = LD->getMemoryVT();
7446 if (!VT.isFloatingPoint() ||
7447 VT != ST->getMemoryVT() ||
7448 LD->isNonTemporal() ||
7449 ST->isNonTemporal() ||
7450 LD->getPointerInfo().getAddrSpace() != 0 ||
7451 ST->getPointerInfo().getAddrSpace() != 0)
7454 EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits());
7455 if (!TLI.isOperationLegal(ISD::LOAD, IntVT) ||
7456 !TLI.isOperationLegal(ISD::STORE, IntVT) ||
7457 !TLI.isDesirableToTransformToIntegerOp(ISD::LOAD, VT) ||
7458 !TLI.isDesirableToTransformToIntegerOp(ISD::STORE, VT))
7461 unsigned LDAlign = LD->getAlignment();
7462 unsigned STAlign = ST->getAlignment();
7463 Type *IntVTTy = IntVT.getTypeForEVT(*DAG.getContext());
7464 unsigned ABIAlign = TLI.getDataLayout()->getABITypeAlignment(IntVTTy);
7465 if (LDAlign < ABIAlign || STAlign < ABIAlign)
7468 SDValue NewLD = DAG.getLoad(IntVT, Value.getDebugLoc(),
7469 LD->getChain(), LD->getBasePtr(),
7470 LD->getPointerInfo(),
7471 false, false, false, LDAlign);
7473 SDValue NewST = DAG.getStore(NewLD.getValue(1), N->getDebugLoc(),
7474 NewLD, ST->getBasePtr(),
7475 ST->getPointerInfo(),
7476 false, false, STAlign);
7478 AddToWorkList(NewLD.getNode());
7479 AddToWorkList(NewST.getNode());
7480 WorkListRemover DeadNodes(*this);
7481 DAG.ReplaceAllUsesOfValueWith(Value.getValue(1), NewLD.getValue(1));
7489 /// Returns the base pointer and an integer offset from that object.
7490 static std::pair<SDValue, int64_t> GetPointerBaseAndOffset(SDValue Ptr) {
7491 if (Ptr->getOpcode() == ISD::ADD && isa<ConstantSDNode>(Ptr->getOperand(1))) {
7492 int64_t Offset = cast<ConstantSDNode>(Ptr->getOperand(1))->getSExtValue();
7493 SDValue Base = Ptr->getOperand(0);
7494 return std::make_pair(Base, Offset);
7497 return std::make_pair(Ptr, 0);
7500 /// Holds a pointer to an LSBaseSDNode as well as information on where it
7501 /// is located in a sequence of memory operations connected by a chain.
7503 MemOpLink (LSBaseSDNode *N, int64_t Offset, unsigned Seq):
7504 MemNode(N), OffsetFromBase(Offset), SequenceNum(Seq) { }
7505 // Ptr to the mem node.
7506 LSBaseSDNode *MemNode;
7507 // Offset from the base ptr.
7508 int64_t OffsetFromBase;
7509 // What is the sequence number of this mem node.
7510 // Lowest mem operand in the DAG starts at zero.
7511 unsigned SequenceNum;
7514 /// Sorts store nodes in a link according to their offset from a shared
7516 struct ConsecutiveMemoryChainSorter {
7517 bool operator()(MemOpLink LHS, MemOpLink RHS) {
7518 return LHS.OffsetFromBase < RHS.OffsetFromBase;
7522 bool DAGCombiner::MergeConsecutiveStores(StoreSDNode* St) {
7523 EVT MemVT = St->getMemoryVT();
7524 int64_t ElementSizeBytes = MemVT.getSizeInBits()/8;
7526 // Don't merge vectors into wider inputs.
7527 if (MemVT.isVector() || !MemVT.isSimple())
7530 // Perform an early exit check. Do not bother looking at stored values that
7531 // are not constants or loads.
7532 SDValue StoredVal = St->getValue();
7533 bool IsLoadSrc = isa<LoadSDNode>(StoredVal);
7534 if (!isa<ConstantSDNode>(StoredVal) && !isa<ConstantFPSDNode>(StoredVal) &&
7538 // Only look at ends of store sequences.
7539 SDValue Chain = SDValue(St, 1);
7540 if (Chain->hasOneUse() && Chain->use_begin()->getOpcode() == ISD::STORE)
7543 // This holds the base pointer and the offset in bytes from the base pointer.
7544 std::pair<SDValue, int64_t> BasePtr =
7545 GetPointerBaseAndOffset(St->getBasePtr());
7547 // We must have a base and an offset.
7548 if (!BasePtr.first.getNode())
7551 // Do not handle stores to undef base pointers.
7552 if (BasePtr.first.getOpcode() == ISD::UNDEF)
7555 SmallVector<MemOpLink, 8> StoreNodes;
7556 // Walk up the chain and look for nodes with offsets from the same
7557 // base pointer. Stop when reaching an instruction with a different kind
7558 // or instruction which has a different base pointer.
7560 StoreSDNode *Index = St;
7562 // If the chain has more than one use, then we can't reorder the mem ops.
7563 if (Index != St && !SDValue(Index, 1)->hasOneUse())
7566 // Find the base pointer and offset for this memory node.
7567 std::pair<SDValue, int64_t> Ptr =
7568 GetPointerBaseAndOffset(Index->getBasePtr());
7570 // Check that the base pointer is the same as the original one.
7571 if (Ptr.first.getNode() != BasePtr.first.getNode())
7574 // Check that the alignment is the same.
7575 if (Index->getAlignment() != St->getAlignment())
7578 // The memory operands must not be volatile.
7579 if (Index->isVolatile() || Index->isIndexed())
7583 if (StoreSDNode *St = dyn_cast<StoreSDNode>(Index))
7584 if (St->isTruncatingStore())
7587 // The stored memory type must be the same.
7588 if (Index->getMemoryVT() != MemVT)
7591 // We do not allow unaligned stores because we want to prevent overriding
7593 if (Index->getAlignment()*8 != MemVT.getSizeInBits())
7596 // We found a potential memory operand to merge.
7597 StoreNodes.push_back(MemOpLink(Index, Ptr.second, Seq++));
7599 // Move up the chain to the next memory operation.
7600 Index = dyn_cast<StoreSDNode>(Index->getChain().getNode());
7603 // Check if there is anything to merge.
7604 if (StoreNodes.size() < 2)
7607 // Sort the memory operands according to their distance from the base pointer.
7608 std::sort(StoreNodes.begin(), StoreNodes.end(),
7609 ConsecutiveMemoryChainSorter());
7611 // Scan the memory operations on the chain and find the first non-consecutive
7612 // store memory address.
7613 unsigned LastConsecutiveStore = 0;
7614 int64_t StartAddress = StoreNodes[0].OffsetFromBase;
7615 for (unsigned i=1; i<StoreNodes.size(); ++i) {
7616 int64_t CurrAddress = StoreNodes[i].OffsetFromBase;
7617 if (CurrAddress - StartAddress != (ElementSizeBytes * i))
7620 // Mark this node as useful.
7621 LastConsecutiveStore = i;
7624 // The node with the lowest store address.
7625 LSBaseSDNode *FirstInChain = StoreNodes[0].MemNode;
7627 // Store the constants into memory as one consecutive store.
7629 unsigned LastLegalType = 0;
7630 unsigned LastLegalVectorType = 0;
7631 bool NonZero = false;
7632 for (unsigned i=0; i<LastConsecutiveStore+1; ++i) {
7633 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
7634 SDValue StoredVal = St->getValue();
7636 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(StoredVal)) {
7637 NonZero |= !C->isNullValue();
7638 } else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(StoredVal)) {
7639 NonZero |= !C->getConstantFPValue()->isNullValue();
7645 // Find a legal type for the constant store.
7646 unsigned StoreBW = (i+1) * ElementSizeBytes * 8;
7647 EVT StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
7648 if (TLI.isTypeLegal(StoreTy))
7649 LastLegalType = i+1;
7651 // Find a legal type for the vector store.
7652 EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
7653 if (TLI.isTypeLegal(Ty))
7654 LastLegalVectorType = i + 1;
7657 // We only use vectors if the constant is known to be zero.
7659 LastLegalVectorType = 0;
7661 // Check if we found a legal integer type to store.
7662 if (LastLegalType == 0 && LastLegalVectorType == 0)
7665 bool UseVector = LastLegalVectorType > LastLegalType;
7666 unsigned NumElem = UseVector ? LastLegalVectorType : LastLegalType;
7668 // Make sure we have something to merge.
7672 unsigned EarliestNodeUsed = 0;
7673 for (unsigned i=0; i < NumElem; ++i) {
7674 // Find a chain for the new wide-store operand. Notice that some
7675 // of the store nodes that we found may not be selected for inclusion
7676 // in the wide store. The chain we use needs to be the chain of the
7677 // earliest store node which is *used* and replaced by the wide store.
7678 if (StoreNodes[i].SequenceNum > StoreNodes[EarliestNodeUsed].SequenceNum)
7679 EarliestNodeUsed = i;
7682 // The earliest Node in the DAG.
7683 LSBaseSDNode *EarliestOp = StoreNodes[EarliestNodeUsed].MemNode;
7684 DebugLoc DL = StoreNodes[0].MemNode->getDebugLoc();
7688 // Find a legal type for the vector store.
7689 EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem);
7690 assert(TLI.isTypeLegal(Ty) && "Illegal vector store");
7691 StoredVal = DAG.getConstant(0, Ty);
7693 unsigned StoreBW = NumElem * ElementSizeBytes * 8;
7694 APInt StoreInt(StoreBW, 0);
7696 // Construct a single integer constant which is made of the smaller
7698 bool IsLE = TLI.isLittleEndian();
7699 for (unsigned i = 0; i < NumElem ; ++i) {
7700 unsigned Idx = IsLE ?(NumElem - 1 - i) : i;
7701 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[Idx].MemNode);
7702 SDValue Val = St->getValue();
7703 StoreInt<<=ElementSizeBytes*8;
7704 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Val)) {
7705 StoreInt|=C->getAPIntValue().zext(StoreBW);
7706 } else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Val)) {
7707 StoreInt|= C->getValueAPF().bitcastToAPInt().zext(StoreBW);
7709 assert(false && "Invalid constant element type");
7713 // Create the new Load and Store operations.
7714 EVT StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
7715 StoredVal = DAG.getConstant(StoreInt, StoreTy);
7718 SDValue NewStore = DAG.getStore(EarliestOp->getChain(), DL, StoredVal,
7719 FirstInChain->getBasePtr(),
7720 FirstInChain->getPointerInfo(),
7722 FirstInChain->getAlignment());
7724 // Replace the first store with the new store
7725 CombineTo(EarliestOp, NewStore);
7726 // Erase all other stores.
7727 for (unsigned i = 0; i < NumElem ; ++i) {
7728 if (StoreNodes[i].MemNode == EarliestOp)
7730 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
7731 // ReplaceAllUsesWith will replace all uses that existed when it was
7732 // called, but graph optimizations may cause new ones to appear. For
7733 // example, the case in pr14333 looks like
7735 // St's chain -> St -> another store -> X
7737 // And the only difference from St to the other store is the chain.
7738 // When we change it's chain to be St's chain they become identical,
7739 // get CSEed and the net result is that X is now a use of St.
7740 // Since we know that St is redundant, just iterate.
7741 while (!St->use_empty())
7742 DAG.ReplaceAllUsesWith(SDValue(St, 0), St->getChain());
7743 removeFromWorkList(St);
7750 // Below we handle the case of multiple consecutive stores that
7751 // come from multiple consecutive loads. We merge them into a single
7752 // wide load and a single wide store.
7754 // Look for load nodes which are used by the stored values.
7755 SmallVector<MemOpLink, 8> LoadNodes;
7757 // Find acceptable loads. Loads need to have the same chain (token factor),
7758 // must not be zext, volatile, indexed, and they must be consecutive.
7760 for (unsigned i=0; i<LastConsecutiveStore+1; ++i) {
7761 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
7762 LoadSDNode *Ld = dyn_cast<LoadSDNode>(St->getValue());
7765 // Loads must only have one use.
7766 if (!Ld->hasNUsesOfValue(1, 0))
7769 // Check that the alignment is the same as the stores.
7770 if (Ld->getAlignment() != St->getAlignment())
7773 // The memory operands must not be volatile.
7774 if (Ld->isVolatile() || Ld->isIndexed())
7777 // We do not accept ext loads.
7778 if (Ld->getExtensionType() != ISD::NON_EXTLOAD)
7781 // The stored memory type must be the same.
7782 if (Ld->getMemoryVT() != MemVT)
7785 std::pair<SDValue, int64_t> LdPtr =
7786 GetPointerBaseAndOffset(Ld->getBasePtr());
7788 // If this is not the first ptr that we check.
7789 if (LdBasePtr.getNode()) {
7790 // The base ptr must be the same.
7791 if (LdPtr.first != LdBasePtr)
7794 // Check that all other base pointers are the same as this one.
7795 LdBasePtr = LdPtr.first;
7798 // We found a potential memory operand to merge.
7799 LoadNodes.push_back(MemOpLink(Ld, LdPtr.second, 0));
7802 if (LoadNodes.size() < 2)
7805 // Scan the memory operations on the chain and find the first non-consecutive
7806 // load memory address. These variables hold the index in the store node
7808 unsigned LastConsecutiveLoad = 0;
7809 // This variable refers to the size and not index in the array.
7810 unsigned LastLegalVectorType = 0;
7811 unsigned LastLegalIntegerType = 0;
7812 StartAddress = LoadNodes[0].OffsetFromBase;
7813 SDValue FirstChain = LoadNodes[0].MemNode->getChain();
7814 for (unsigned i = 1; i < LoadNodes.size(); ++i) {
7815 // All loads much share the same chain.
7816 if (LoadNodes[i].MemNode->getChain() != FirstChain)
7819 int64_t CurrAddress = LoadNodes[i].OffsetFromBase;
7820 if (CurrAddress - StartAddress != (ElementSizeBytes * i))
7822 LastConsecutiveLoad = i;
7824 // Find a legal type for the vector store.
7825 EVT StoreTy = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
7826 if (TLI.isTypeLegal(StoreTy))
7827 LastLegalVectorType = i + 1;
7829 // Find a legal type for the integer store.
7830 unsigned StoreBW = (i+1) * ElementSizeBytes * 8;
7831 StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
7832 if (TLI.isTypeLegal(StoreTy))
7833 LastLegalIntegerType = i + 1;
7836 // Only use vector types if the vector type is larger than the integer type.
7837 // If they are the same, use integers.
7838 bool UseVectorTy = LastLegalVectorType > LastLegalIntegerType;
7839 unsigned LastLegalType = std::max(LastLegalVectorType, LastLegalIntegerType);
7841 // We add +1 here because the LastXXX variables refer to location while
7842 // the NumElem refers to array/index size.
7843 unsigned NumElem = std::min(LastConsecutiveStore, LastConsecutiveLoad) + 1;
7844 NumElem = std::min(LastLegalType, NumElem);
7849 // The earliest Node in the DAG.
7850 unsigned EarliestNodeUsed = 0;
7851 LSBaseSDNode *EarliestOp = StoreNodes[EarliestNodeUsed].MemNode;
7852 for (unsigned i=1; i<NumElem; ++i) {
7853 // Find a chain for the new wide-store operand. Notice that some
7854 // of the store nodes that we found may not be selected for inclusion
7855 // in the wide store. The chain we use needs to be the chain of the
7856 // earliest store node which is *used* and replaced by the wide store.
7857 if (StoreNodes[i].SequenceNum > StoreNodes[EarliestNodeUsed].SequenceNum)
7858 EarliestNodeUsed = i;
7861 // Find if it is better to use vectors or integers to load and store
7865 JointMemOpVT = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem);
7867 unsigned StoreBW = NumElem * ElementSizeBytes * 8;
7868 JointMemOpVT = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
7871 DebugLoc LoadDL = LoadNodes[0].MemNode->getDebugLoc();
7872 DebugLoc StoreDL = StoreNodes[0].MemNode->getDebugLoc();
7874 LoadSDNode *FirstLoad = cast<LoadSDNode>(LoadNodes[0].MemNode);
7875 SDValue NewLoad = DAG.getLoad(JointMemOpVT, LoadDL,
7876 FirstLoad->getChain(),
7877 FirstLoad->getBasePtr(),
7878 FirstLoad->getPointerInfo(),
7879 false, false, false,
7880 FirstLoad->getAlignment());
7882 SDValue NewStore = DAG.getStore(EarliestOp->getChain(), StoreDL, NewLoad,
7883 FirstInChain->getBasePtr(),
7884 FirstInChain->getPointerInfo(), false, false,
7885 FirstInChain->getAlignment());
7887 // Replace one of the loads with the new load.
7888 LoadSDNode *Ld = cast<LoadSDNode>(LoadNodes[0].MemNode);
7889 DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1),
7890 SDValue(NewLoad.getNode(), 1));
7892 // Remove the rest of the load chains.
7893 for (unsigned i = 1; i < NumElem ; ++i) {
7894 // Replace all chain users of the old load nodes with the chain of the new
7896 LoadSDNode *Ld = cast<LoadSDNode>(LoadNodes[i].MemNode);
7897 DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1), Ld->getChain());
7900 // Replace the first store with the new store.
7901 CombineTo(EarliestOp, NewStore);
7902 // Erase all other stores.
7903 for (unsigned i = 0; i < NumElem ; ++i) {
7904 // Remove all Store nodes.
7905 if (StoreNodes[i].MemNode == EarliestOp)
7907 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
7908 DAG.ReplaceAllUsesOfValueWith(SDValue(St, 0), St->getChain());
7909 removeFromWorkList(St);
7916 SDValue DAGCombiner::visitSTORE(SDNode *N) {
7917 StoreSDNode *ST = cast<StoreSDNode>(N);
7918 SDValue Chain = ST->getChain();
7919 SDValue Value = ST->getValue();
7920 SDValue Ptr = ST->getBasePtr();
7922 // If this is a store of a bit convert, store the input value if the
7923 // resultant store does not need a higher alignment than the original.
7924 if (Value.getOpcode() == ISD::BITCAST && !ST->isTruncatingStore() &&
7925 ST->isUnindexed()) {
7926 unsigned OrigAlign = ST->getAlignment();
7927 EVT SVT = Value.getOperand(0).getValueType();
7928 unsigned Align = TLI.getDataLayout()->
7929 getABITypeAlignment(SVT.getTypeForEVT(*DAG.getContext()));
7930 if (Align <= OrigAlign &&
7931 ((!LegalOperations && !ST->isVolatile()) ||
7932 TLI.isOperationLegalOrCustom(ISD::STORE, SVT)))
7933 return DAG.getStore(Chain, N->getDebugLoc(), Value.getOperand(0),
7934 Ptr, ST->getPointerInfo(), ST->isVolatile(),
7935 ST->isNonTemporal(), OrigAlign);
7938 // Turn 'store undef, Ptr' -> nothing.
7939 if (Value.getOpcode() == ISD::UNDEF && ST->isUnindexed())
7942 // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
7943 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Value)) {
7944 // NOTE: If the original store is volatile, this transform must not increase
7945 // the number of stores. For example, on x86-32 an f64 can be stored in one
7946 // processor operation but an i64 (which is not legal) requires two. So the
7947 // transform should not be done in this case.
7948 if (Value.getOpcode() != ISD::TargetConstantFP) {
7950 switch (CFP->getValueType(0).getSimpleVT().SimpleTy) {
7951 default: llvm_unreachable("Unknown FP type");
7952 case MVT::f16: // We don't do this for these yet.
7958 if ((isTypeLegal(MVT::i32) && !LegalOperations && !ST->isVolatile()) ||
7959 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
7960 Tmp = DAG.getConstant((uint32_t)CFP->getValueAPF().
7961 bitcastToAPInt().getZExtValue(), MVT::i32);
7962 return DAG.getStore(Chain, N->getDebugLoc(), Tmp,
7963 Ptr, ST->getPointerInfo(), ST->isVolatile(),
7964 ST->isNonTemporal(), ST->getAlignment());
7968 if ((TLI.isTypeLegal(MVT::i64) && !LegalOperations &&
7969 !ST->isVolatile()) ||
7970 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i64)) {
7971 Tmp = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
7972 getZExtValue(), MVT::i64);
7973 return DAG.getStore(Chain, N->getDebugLoc(), Tmp,
7974 Ptr, ST->getPointerInfo(), ST->isVolatile(),
7975 ST->isNonTemporal(), ST->getAlignment());
7978 if (!ST->isVolatile() &&
7979 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
7980 // Many FP stores are not made apparent until after legalize, e.g. for
7981 // argument passing. Since this is so common, custom legalize the
7982 // 64-bit integer store into two 32-bit stores.
7983 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
7984 SDValue Lo = DAG.getConstant(Val & 0xFFFFFFFF, MVT::i32);
7985 SDValue Hi = DAG.getConstant(Val >> 32, MVT::i32);
7986 if (TLI.isBigEndian()) std::swap(Lo, Hi);
7988 unsigned Alignment = ST->getAlignment();
7989 bool isVolatile = ST->isVolatile();
7990 bool isNonTemporal = ST->isNonTemporal();
7992 SDValue St0 = DAG.getStore(Chain, ST->getDebugLoc(), Lo,
7993 Ptr, ST->getPointerInfo(),
7994 isVolatile, isNonTemporal,
7995 ST->getAlignment());
7996 Ptr = DAG.getNode(ISD::ADD, N->getDebugLoc(), Ptr.getValueType(), Ptr,
7997 DAG.getConstant(4, Ptr.getValueType()));
7998 Alignment = MinAlign(Alignment, 4U);
7999 SDValue St1 = DAG.getStore(Chain, ST->getDebugLoc(), Hi,
8000 Ptr, ST->getPointerInfo().getWithOffset(4),
8001 isVolatile, isNonTemporal,
8003 return DAG.getNode(ISD::TokenFactor, N->getDebugLoc(), MVT::Other,
8012 // Try to infer better alignment information than the store already has.
8013 if (OptLevel != CodeGenOpt::None && ST->isUnindexed()) {
8014 if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
8015 if (Align > ST->getAlignment())
8016 return DAG.getTruncStore(Chain, N->getDebugLoc(), Value,
8017 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
8018 ST->isVolatile(), ST->isNonTemporal(), Align);
8022 // Try transforming a pair floating point load / store ops to integer
8023 // load / store ops.
8024 SDValue NewST = TransformFPLoadStorePair(N);
8025 if (NewST.getNode())
8029 // Walk up chain skipping non-aliasing memory nodes.
8030 SDValue BetterChain = FindBetterChain(N, Chain);
8032 // If there is a better chain.
8033 if (Chain != BetterChain) {
8036 // Replace the chain to avoid dependency.
8037 if (ST->isTruncatingStore()) {
8038 ReplStore = DAG.getTruncStore(BetterChain, N->getDebugLoc(), Value, Ptr,
8039 ST->getPointerInfo(),
8040 ST->getMemoryVT(), ST->isVolatile(),
8041 ST->isNonTemporal(), ST->getAlignment());
8043 ReplStore = DAG.getStore(BetterChain, N->getDebugLoc(), Value, Ptr,
8044 ST->getPointerInfo(),
8045 ST->isVolatile(), ST->isNonTemporal(),
8046 ST->getAlignment());
8049 // Create token to keep both nodes around.
8050 SDValue Token = DAG.getNode(ISD::TokenFactor, N->getDebugLoc(),
8051 MVT::Other, Chain, ReplStore);
8053 // Make sure the new and old chains are cleaned up.
8054 AddToWorkList(Token.getNode());
8056 // Don't add users to work list.
8057 return CombineTo(N, Token, false);
8061 // Try transforming N to an indexed store.
8062 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
8063 return SDValue(N, 0);
8065 // FIXME: is there such a thing as a truncating indexed store?
8066 if (ST->isTruncatingStore() && ST->isUnindexed() &&
8067 Value.getValueType().isInteger()) {
8068 // See if we can simplify the input to this truncstore with knowledge that
8069 // only the low bits are being used. For example:
8070 // "truncstore (or (shl x, 8), y), i8" -> "truncstore y, i8"
8072 GetDemandedBits(Value,
8073 APInt::getLowBitsSet(
8074 Value.getValueType().getScalarType().getSizeInBits(),
8075 ST->getMemoryVT().getScalarType().getSizeInBits()));
8076 AddToWorkList(Value.getNode());
8077 if (Shorter.getNode())
8078 return DAG.getTruncStore(Chain, N->getDebugLoc(), Shorter,
8079 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
8080 ST->isVolatile(), ST->isNonTemporal(),
8081 ST->getAlignment());
8083 // Otherwise, see if we can simplify the operation with
8084 // SimplifyDemandedBits, which only works if the value has a single use.
8085 if (SimplifyDemandedBits(Value,
8086 APInt::getLowBitsSet(
8087 Value.getValueType().getScalarType().getSizeInBits(),
8088 ST->getMemoryVT().getScalarType().getSizeInBits())))
8089 return SDValue(N, 0);
8092 // If this is a load followed by a store to the same location, then the store
8094 if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Value)) {
8095 if (Ld->getBasePtr() == Ptr && ST->getMemoryVT() == Ld->getMemoryVT() &&
8096 ST->isUnindexed() && !ST->isVolatile() &&
8097 // There can't be any side effects between the load and store, such as
8099 Chain.reachesChainWithoutSideEffects(SDValue(Ld, 1))) {
8100 // The store is dead, remove it.
8105 // If this is an FP_ROUND or TRUNC followed by a store, fold this into a
8106 // truncating store. We can do this even if this is already a truncstore.
8107 if ((Value.getOpcode() == ISD::FP_ROUND || Value.getOpcode() == ISD::TRUNCATE)
8108 && Value.getNode()->hasOneUse() && ST->isUnindexed() &&
8109 TLI.isTruncStoreLegal(Value.getOperand(0).getValueType(),
8110 ST->getMemoryVT())) {
8111 return DAG.getTruncStore(Chain, N->getDebugLoc(), Value.getOperand(0),
8112 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
8113 ST->isVolatile(), ST->isNonTemporal(),
8114 ST->getAlignment());
8117 // Only perform this optimization before the types are legal, because we
8118 // don't want to perform this optimization on every DAGCombine invocation.
8119 if (!LegalTypes && MergeConsecutiveStores(ST))
8120 return SDValue(N, 0);
8122 return ReduceLoadOpStoreWidth(N);
8125 SDValue DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) {
8126 SDValue InVec = N->getOperand(0);
8127 SDValue InVal = N->getOperand(1);
8128 SDValue EltNo = N->getOperand(2);
8129 DebugLoc dl = N->getDebugLoc();
8131 // If the inserted element is an UNDEF, just use the input vector.
8132 if (InVal.getOpcode() == ISD::UNDEF)
8135 EVT VT = InVec.getValueType();
8137 // If we can't generate a legal BUILD_VECTOR, exit
8138 if (LegalOperations && !TLI.isOperationLegal(ISD::BUILD_VECTOR, VT))
8141 // Check that we know which element is being inserted
8142 if (!isa<ConstantSDNode>(EltNo))
8144 unsigned Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
8146 // Check that the operand is a BUILD_VECTOR (or UNDEF, which can essentially
8147 // be converted to a BUILD_VECTOR). Fill in the Ops vector with the
8149 SmallVector<SDValue, 8> Ops;
8150 if (InVec.getOpcode() == ISD::BUILD_VECTOR) {
8151 Ops.append(InVec.getNode()->op_begin(),
8152 InVec.getNode()->op_end());
8153 } else if (InVec.getOpcode() == ISD::UNDEF) {
8154 unsigned NElts = VT.getVectorNumElements();
8155 Ops.append(NElts, DAG.getUNDEF(InVal.getValueType()));
8160 // Insert the element
8161 if (Elt < Ops.size()) {
8162 // All the operands of BUILD_VECTOR must have the same type;
8163 // we enforce that here.
8164 EVT OpVT = Ops[0].getValueType();
8165 if (InVal.getValueType() != OpVT)
8166 InVal = OpVT.bitsGT(InVal.getValueType()) ?
8167 DAG.getNode(ISD::ANY_EXTEND, dl, OpVT, InVal) :
8168 DAG.getNode(ISD::TRUNCATE, dl, OpVT, InVal);
8172 // Return the new vector
8173 return DAG.getNode(ISD::BUILD_VECTOR, dl,
8174 VT, &Ops[0], Ops.size());
8177 SDValue DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) {
8178 // (vextract (scalar_to_vector val, 0) -> val
8179 SDValue InVec = N->getOperand(0);
8180 EVT VT = InVec.getValueType();
8181 EVT NVT = N->getValueType(0);
8183 if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR) {
8184 // Check if the result type doesn't match the inserted element type. A
8185 // SCALAR_TO_VECTOR may truncate the inserted element and the
8186 // EXTRACT_VECTOR_ELT may widen the extracted vector.
8187 SDValue InOp = InVec.getOperand(0);
8188 if (InOp.getValueType() != NVT) {
8189 assert(InOp.getValueType().isInteger() && NVT.isInteger());
8190 return DAG.getSExtOrTrunc(InOp, InVec.getDebugLoc(), NVT);
8195 SDValue EltNo = N->getOperand(1);
8196 bool ConstEltNo = isa<ConstantSDNode>(EltNo);
8198 // Transform: (EXTRACT_VECTOR_ELT( VECTOR_SHUFFLE )) -> EXTRACT_VECTOR_ELT.
8199 // We only perform this optimization before the op legalization phase because
8200 // we may introduce new vector instructions which are not backed by TD
8201 // patterns. For example on AVX, extracting elements from a wide vector
8202 // without using extract_subvector.
8203 if (InVec.getOpcode() == ISD::VECTOR_SHUFFLE
8204 && ConstEltNo && !LegalOperations) {
8205 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
8206 int NumElem = VT.getVectorNumElements();
8207 ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(InVec);
8208 // Find the new index to extract from.
8209 int OrigElt = SVOp->getMaskElt(Elt);
8211 // Extracting an undef index is undef.
8213 return DAG.getUNDEF(NVT);
8215 // Select the right vector half to extract from.
8216 if (OrigElt < NumElem) {
8217 InVec = InVec->getOperand(0);
8219 InVec = InVec->getOperand(1);
8223 EVT IndexTy = N->getOperand(1).getValueType();
8224 return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, N->getDebugLoc(), NVT,
8225 InVec, DAG.getConstant(OrigElt, IndexTy));
8228 // Perform only after legalization to ensure build_vector / vector_shuffle
8229 // optimizations have already been done.
8230 if (!LegalOperations) return SDValue();
8232 // (vextract (v4f32 load $addr), c) -> (f32 load $addr+c*size)
8233 // (vextract (v4f32 s2v (f32 load $addr)), c) -> (f32 load $addr+c*size)
8234 // (vextract (v4f32 shuffle (load $addr), <1,u,u,u>), 0) -> (f32 load $addr)
8237 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
8238 bool NewLoad = false;
8239 bool BCNumEltsChanged = false;
8240 EVT ExtVT = VT.getVectorElementType();
8243 // If the result of load has to be truncated, then it's not necessarily
8245 if (NVT.bitsLT(LVT) && !TLI.isTruncateFree(LVT, NVT))
8248 if (InVec.getOpcode() == ISD::BITCAST) {
8249 // Don't duplicate a load with other uses.
8250 if (!InVec.hasOneUse())
8253 EVT BCVT = InVec.getOperand(0).getValueType();
8254 if (!BCVT.isVector() || ExtVT.bitsGT(BCVT.getVectorElementType()))
8256 if (VT.getVectorNumElements() != BCVT.getVectorNumElements())
8257 BCNumEltsChanged = true;
8258 InVec = InVec.getOperand(0);
8259 ExtVT = BCVT.getVectorElementType();
8263 LoadSDNode *LN0 = NULL;
8264 const ShuffleVectorSDNode *SVN = NULL;
8265 if (ISD::isNormalLoad(InVec.getNode())) {
8266 LN0 = cast<LoadSDNode>(InVec);
8267 } else if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR &&
8268 InVec.getOperand(0).getValueType() == ExtVT &&
8269 ISD::isNormalLoad(InVec.getOperand(0).getNode())) {
8270 // Don't duplicate a load with other uses.
8271 if (!InVec.hasOneUse())
8274 LN0 = cast<LoadSDNode>(InVec.getOperand(0));
8275 } else if ((SVN = dyn_cast<ShuffleVectorSDNode>(InVec))) {
8276 // (vextract (vector_shuffle (load $addr), v2, <1, u, u, u>), 1)
8278 // (load $addr+1*size)
8280 // Don't duplicate a load with other uses.
8281 if (!InVec.hasOneUse())
8284 // If the bit convert changed the number of elements, it is unsafe
8285 // to examine the mask.
8286 if (BCNumEltsChanged)
8289 // Select the input vector, guarding against out of range extract vector.
8290 unsigned NumElems = VT.getVectorNumElements();
8291 int Idx = (Elt > (int)NumElems) ? -1 : SVN->getMaskElt(Elt);
8292 InVec = (Idx < (int)NumElems) ? InVec.getOperand(0) : InVec.getOperand(1);
8294 if (InVec.getOpcode() == ISD::BITCAST) {
8295 // Don't duplicate a load with other uses.
8296 if (!InVec.hasOneUse())
8299 InVec = InVec.getOperand(0);
8301 if (ISD::isNormalLoad(InVec.getNode())) {
8302 LN0 = cast<LoadSDNode>(InVec);
8303 Elt = (Idx < (int)NumElems) ? Idx : Idx - (int)NumElems;
8307 // Make sure we found a non-volatile load and the extractelement is
8309 if (!LN0 || !LN0->hasNUsesOfValue(1,0) || LN0->isVolatile())
8312 // If Idx was -1 above, Elt is going to be -1, so just return undef.
8314 return DAG.getUNDEF(LVT);
8316 unsigned Align = LN0->getAlignment();
8318 // Check the resultant load doesn't need a higher alignment than the
8322 ->getABITypeAlignment(LVT.getTypeForEVT(*DAG.getContext()));
8324 if (NewAlign > Align || !TLI.isOperationLegalOrCustom(ISD::LOAD, LVT))
8330 SDValue NewPtr = LN0->getBasePtr();
8331 unsigned PtrOff = 0;
8334 PtrOff = LVT.getSizeInBits() * Elt / 8;
8335 EVT PtrType = NewPtr.getValueType();
8336 if (TLI.isBigEndian())
8337 PtrOff = VT.getSizeInBits() / 8 - PtrOff;
8338 NewPtr = DAG.getNode(ISD::ADD, N->getDebugLoc(), PtrType, NewPtr,
8339 DAG.getConstant(PtrOff, PtrType));
8342 // The replacement we need to do here is a little tricky: we need to
8343 // replace an extractelement of a load with a load.
8344 // Use ReplaceAllUsesOfValuesWith to do the replacement.
8345 // Note that this replacement assumes that the extractvalue is the only
8346 // use of the load; that's okay because we don't want to perform this
8347 // transformation in other cases anyway.
8350 if (NVT.bitsGT(LVT)) {
8351 // If the result type of vextract is wider than the load, then issue an
8352 // extending load instead.
8353 ISD::LoadExtType ExtType = TLI.isLoadExtLegal(ISD::ZEXTLOAD, LVT)
8354 ? ISD::ZEXTLOAD : ISD::EXTLOAD;
8355 Load = DAG.getExtLoad(ExtType, N->getDebugLoc(), NVT, LN0->getChain(),
8356 NewPtr, LN0->getPointerInfo().getWithOffset(PtrOff),
8357 LVT, LN0->isVolatile(), LN0->isNonTemporal(),Align);
8358 Chain = Load.getValue(1);
8360 Load = DAG.getLoad(LVT, N->getDebugLoc(), LN0->getChain(), NewPtr,
8361 LN0->getPointerInfo().getWithOffset(PtrOff),
8362 LN0->isVolatile(), LN0->isNonTemporal(),
8363 LN0->isInvariant(), Align);
8364 Chain = Load.getValue(1);
8365 if (NVT.bitsLT(LVT))
8366 Load = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), NVT, Load);
8368 Load = DAG.getNode(ISD::BITCAST, N->getDebugLoc(), NVT, Load);
8370 WorkListRemover DeadNodes(*this);
8371 SDValue From[] = { SDValue(N, 0), SDValue(LN0,1) };
8372 SDValue To[] = { Load, Chain };
8373 DAG.ReplaceAllUsesOfValuesWith(From, To, 2);
8374 // Since we're explcitly calling ReplaceAllUses, add the new node to the
8375 // worklist explicitly as well.
8376 AddToWorkList(Load.getNode());
8377 AddUsersToWorkList(Load.getNode()); // Add users too
8378 // Make sure to revisit this node to clean it up; it will usually be dead.
8380 return SDValue(N, 0);
8386 // Simplify (build_vec (ext )) to (bitcast (build_vec ))
8387 SDValue DAGCombiner::reduceBuildVecExtToExtBuildVec(SDNode *N) {
8388 // We perform this optimization post type-legalization because
8389 // the type-legalizer often scalarizes integer-promoted vectors.
8390 // Performing this optimization before may create bit-casts which
8391 // will be type-legalized to complex code sequences.
8392 // We perform this optimization only before the operation legalizer because we
8393 // may introduce illegal operations.
8394 if (Level != AfterLegalizeVectorOps && Level != AfterLegalizeTypes)
8397 unsigned NumInScalars = N->getNumOperands();
8398 DebugLoc dl = N->getDebugLoc();
8399 EVT VT = N->getValueType(0);
8401 // Check to see if this is a BUILD_VECTOR of a bunch of values
8402 // which come from any_extend or zero_extend nodes. If so, we can create
8403 // a new BUILD_VECTOR using bit-casts which may enable other BUILD_VECTOR
8404 // optimizations. We do not handle sign-extend because we can't fill the sign
8406 EVT SourceType = MVT::Other;
8407 bool AllAnyExt = true;
8409 for (unsigned i = 0; i != NumInScalars; ++i) {
8410 SDValue In = N->getOperand(i);
8411 // Ignore undef inputs.
8412 if (In.getOpcode() == ISD::UNDEF) continue;
8414 bool AnyExt = In.getOpcode() == ISD::ANY_EXTEND;
8415 bool ZeroExt = In.getOpcode() == ISD::ZERO_EXTEND;
8417 // Abort if the element is not an extension.
8418 if (!ZeroExt && !AnyExt) {
8419 SourceType = MVT::Other;
8423 // The input is a ZeroExt or AnyExt. Check the original type.
8424 EVT InTy = In.getOperand(0).getValueType();
8426 // Check that all of the widened source types are the same.
8427 if (SourceType == MVT::Other)
8430 else if (InTy != SourceType) {
8431 // Multiple income types. Abort.
8432 SourceType = MVT::Other;
8436 // Check if all of the extends are ANY_EXTENDs.
8437 AllAnyExt &= AnyExt;
8440 // In order to have valid types, all of the inputs must be extended from the
8441 // same source type and all of the inputs must be any or zero extend.
8442 // Scalar sizes must be a power of two.
8443 EVT OutScalarTy = VT.getScalarType();
8444 bool ValidTypes = SourceType != MVT::Other &&
8445 isPowerOf2_32(OutScalarTy.getSizeInBits()) &&
8446 isPowerOf2_32(SourceType.getSizeInBits());
8448 // Create a new simpler BUILD_VECTOR sequence which other optimizations can
8449 // turn into a single shuffle instruction.
8453 bool isLE = TLI.isLittleEndian();
8454 unsigned ElemRatio = OutScalarTy.getSizeInBits()/SourceType.getSizeInBits();
8455 assert(ElemRatio > 1 && "Invalid element size ratio");
8456 SDValue Filler = AllAnyExt ? DAG.getUNDEF(SourceType):
8457 DAG.getConstant(0, SourceType);
8459 unsigned NewBVElems = ElemRatio * VT.getVectorNumElements();
8460 SmallVector<SDValue, 8> Ops(NewBVElems, Filler);
8462 // Populate the new build_vector
8463 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
8464 SDValue Cast = N->getOperand(i);
8465 assert((Cast.getOpcode() == ISD::ANY_EXTEND ||
8466 Cast.getOpcode() == ISD::ZERO_EXTEND ||
8467 Cast.getOpcode() == ISD::UNDEF) && "Invalid cast opcode");
8469 if (Cast.getOpcode() == ISD::UNDEF)
8470 In = DAG.getUNDEF(SourceType);
8472 In = Cast->getOperand(0);
8473 unsigned Index = isLE ? (i * ElemRatio) :
8474 (i * ElemRatio + (ElemRatio - 1));
8476 assert(Index < Ops.size() && "Invalid index");
8480 // The type of the new BUILD_VECTOR node.
8481 EVT VecVT = EVT::getVectorVT(*DAG.getContext(), SourceType, NewBVElems);
8482 assert(VecVT.getSizeInBits() == VT.getSizeInBits() &&
8483 "Invalid vector size");
8484 // Check if the new vector type is legal.
8485 if (!isTypeLegal(VecVT)) return SDValue();
8487 // Make the new BUILD_VECTOR.
8488 SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, dl, VecVT, &Ops[0], Ops.size());
8490 // The new BUILD_VECTOR node has the potential to be further optimized.
8491 AddToWorkList(BV.getNode());
8492 // Bitcast to the desired type.
8493 return DAG.getNode(ISD::BITCAST, dl, VT, BV);
8496 SDValue DAGCombiner::reduceBuildVecConvertToConvertBuildVec(SDNode *N) {
8497 EVT VT = N->getValueType(0);
8499 unsigned NumInScalars = N->getNumOperands();
8500 DebugLoc dl = N->getDebugLoc();
8502 EVT SrcVT = MVT::Other;
8503 unsigned Opcode = ISD::DELETED_NODE;
8504 unsigned NumDefs = 0;
8506 for (unsigned i = 0; i != NumInScalars; ++i) {
8507 SDValue In = N->getOperand(i);
8508 unsigned Opc = In.getOpcode();
8510 if (Opc == ISD::UNDEF)
8513 // If all scalar values are floats and converted from integers.
8514 if (Opcode == ISD::DELETED_NODE &&
8515 (Opc == ISD::UINT_TO_FP || Opc == ISD::SINT_TO_FP)) {
8517 // If not supported by target, bail out.
8518 if (TLI.getOperationAction(Opcode, VT) != TargetLowering::Legal &&
8519 TLI.getOperationAction(Opcode, VT) != TargetLowering::Custom)
8525 EVT InVT = In.getOperand(0).getValueType();
8527 // If all scalar values are typed differently, bail out. It's chosen to
8528 // simplify BUILD_VECTOR of integer types.
8529 if (SrcVT == MVT::Other)
8536 // If the vector has just one element defined, it's not worth to fold it into
8537 // a vectorized one.
8541 assert((Opcode == ISD::UINT_TO_FP || Opcode == ISD::SINT_TO_FP)
8542 && "Should only handle conversion from integer to float.");
8543 assert(SrcVT != MVT::Other && "Cannot determine source type!");
8545 EVT NVT = EVT::getVectorVT(*DAG.getContext(), SrcVT, NumInScalars);
8546 SmallVector<SDValue, 8> Opnds;
8547 for (unsigned i = 0; i != NumInScalars; ++i) {
8548 SDValue In = N->getOperand(i);
8550 if (In.getOpcode() == ISD::UNDEF)
8551 Opnds.push_back(DAG.getUNDEF(SrcVT));
8553 Opnds.push_back(In.getOperand(0));
8555 SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT,
8556 &Opnds[0], Opnds.size());
8557 AddToWorkList(BV.getNode());
8559 return DAG.getNode(Opcode, dl, VT, BV);
8562 SDValue DAGCombiner::visitBUILD_VECTOR(SDNode *N) {
8563 unsigned NumInScalars = N->getNumOperands();
8564 DebugLoc dl = N->getDebugLoc();
8565 EVT VT = N->getValueType(0);
8567 // A vector built entirely of undefs is undef.
8568 if (ISD::allOperandsUndef(N))
8569 return DAG.getUNDEF(VT);
8571 SDValue V = reduceBuildVecExtToExtBuildVec(N);
8575 V = reduceBuildVecConvertToConvertBuildVec(N);
8579 // Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT
8580 // operations. If so, and if the EXTRACT_VECTOR_ELT vector inputs come from
8581 // at most two distinct vectors, turn this into a shuffle node.
8583 // May only combine to shuffle after legalize if shuffle is legal.
8584 if (LegalOperations &&
8585 !TLI.isOperationLegalOrCustom(ISD::VECTOR_SHUFFLE, VT))
8588 SDValue VecIn1, VecIn2;
8589 for (unsigned i = 0; i != NumInScalars; ++i) {
8590 // Ignore undef inputs.
8591 if (N->getOperand(i).getOpcode() == ISD::UNDEF) continue;
8593 // If this input is something other than a EXTRACT_VECTOR_ELT with a
8594 // constant index, bail out.
8595 if (N->getOperand(i).getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
8596 !isa<ConstantSDNode>(N->getOperand(i).getOperand(1))) {
8597 VecIn1 = VecIn2 = SDValue(0, 0);
8601 // We allow up to two distinct input vectors.
8602 SDValue ExtractedFromVec = N->getOperand(i).getOperand(0);
8603 if (ExtractedFromVec == VecIn1 || ExtractedFromVec == VecIn2)
8606 if (VecIn1.getNode() == 0) {
8607 VecIn1 = ExtractedFromVec;
8608 } else if (VecIn2.getNode() == 0) {
8609 VecIn2 = ExtractedFromVec;
8612 VecIn1 = VecIn2 = SDValue(0, 0);
8617 // If everything is good, we can make a shuffle operation.
8618 if (VecIn1.getNode()) {
8619 SmallVector<int, 8> Mask;
8620 for (unsigned i = 0; i != NumInScalars; ++i) {
8621 if (N->getOperand(i).getOpcode() == ISD::UNDEF) {
8626 // If extracting from the first vector, just use the index directly.
8627 SDValue Extract = N->getOperand(i);
8628 SDValue ExtVal = Extract.getOperand(1);
8629 if (Extract.getOperand(0) == VecIn1) {
8630 unsigned ExtIndex = cast<ConstantSDNode>(ExtVal)->getZExtValue();
8631 if (ExtIndex > VT.getVectorNumElements())
8634 Mask.push_back(ExtIndex);
8638 // Otherwise, use InIdx + VecSize
8639 unsigned Idx = cast<ConstantSDNode>(ExtVal)->getZExtValue();
8640 Mask.push_back(Idx+NumInScalars);
8643 // We can't generate a shuffle node with mismatched input and output types.
8644 // Attempt to transform a single input vector to the correct type.
8645 if ((VT != VecIn1.getValueType())) {
8646 // We don't support shuffeling between TWO values of different types.
8647 if (VecIn2.getNode() != 0)
8650 // We only support widening of vectors which are half the size of the
8651 // output registers. For example XMM->YMM widening on X86 with AVX.
8652 if (VecIn1.getValueType().getSizeInBits()*2 != VT.getSizeInBits())
8655 // If the input vector type has a different base type to the output
8656 // vector type, bail out.
8657 if (VecIn1.getValueType().getVectorElementType() !=
8658 VT.getVectorElementType())
8661 // Widen the input vector by adding undef values.
8662 VecIn1 = DAG.getNode(ISD::CONCAT_VECTORS, dl, VT,
8663 VecIn1, DAG.getUNDEF(VecIn1.getValueType()));
8666 // If VecIn2 is unused then change it to undef.
8667 VecIn2 = VecIn2.getNode() ? VecIn2 : DAG.getUNDEF(VT);
8669 // Check that we were able to transform all incoming values to the same
8671 if (VecIn2.getValueType() != VecIn1.getValueType() ||
8672 VecIn1.getValueType() != VT)
8675 // Only type-legal BUILD_VECTOR nodes are converted to shuffle nodes.
8676 if (!isTypeLegal(VT))
8679 // Return the new VECTOR_SHUFFLE node.
8683 return DAG.getVectorShuffle(VT, dl, Ops[0], Ops[1], &Mask[0]);
8689 SDValue DAGCombiner::visitCONCAT_VECTORS(SDNode *N) {
8690 // TODO: Check to see if this is a CONCAT_VECTORS of a bunch of
8691 // EXTRACT_SUBVECTOR operations. If so, and if the EXTRACT_SUBVECTOR vector
8692 // inputs come from at most two distinct vectors, turn this into a shuffle
8695 // If we only have one input vector, we don't need to do any concatenation.
8696 if (N->getNumOperands() == 1)
8697 return N->getOperand(0);
8699 // Check if all of the operands are undefs.
8700 if (ISD::allOperandsUndef(N))
8701 return DAG.getUNDEF(N->getValueType(0));
8706 SDValue DAGCombiner::visitEXTRACT_SUBVECTOR(SDNode* N) {
8707 EVT NVT = N->getValueType(0);
8708 SDValue V = N->getOperand(0);
8710 if (V->getOpcode() == ISD::INSERT_SUBVECTOR) {
8711 // Handle only simple case where vector being inserted and vector
8712 // being extracted are of same type, and are half size of larger vectors.
8713 EVT BigVT = V->getOperand(0).getValueType();
8714 EVT SmallVT = V->getOperand(1).getValueType();
8715 if (NVT != SmallVT || NVT.getSizeInBits()*2 != BigVT.getSizeInBits())
8718 // Only handle cases where both indexes are constants with the same type.
8719 ConstantSDNode *ExtIdx = dyn_cast<ConstantSDNode>(N->getOperand(1));
8720 ConstantSDNode *InsIdx = dyn_cast<ConstantSDNode>(V->getOperand(2));
8722 if (InsIdx && ExtIdx &&
8723 InsIdx->getValueType(0).getSizeInBits() <= 64 &&
8724 ExtIdx->getValueType(0).getSizeInBits() <= 64) {
8726 // (extract_subvec (insert_subvec V1, V2, InsIdx), ExtIdx)
8728 // indices are equal => V1
8729 // otherwise => (extract_subvec V1, ExtIdx)
8730 if (InsIdx->getZExtValue() == ExtIdx->getZExtValue())
8731 return V->getOperand(1);
8732 return DAG.getNode(ISD::EXTRACT_SUBVECTOR, N->getDebugLoc(), NVT,
8733 V->getOperand(0), N->getOperand(1));
8737 if (V->getOpcode() == ISD::CONCAT_VECTORS) {
8739 // (extract_subvec (concat V1, V2, ...), i)
8742 // Only operand 0 is checked as 'concat' assumes all inputs of the same type.
8743 if (V->getOperand(0).getValueType() != NVT)
8745 unsigned Idx = dyn_cast<ConstantSDNode>(N->getOperand(1))->getZExtValue();
8746 unsigned NumElems = NVT.getVectorNumElements();
8747 assert((Idx % NumElems) == 0 &&
8748 "IDX in concat is not a multiple of the result vector length.");
8749 return V->getOperand(Idx / NumElems);
8755 SDValue DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
8756 EVT VT = N->getValueType(0);
8757 unsigned NumElts = VT.getVectorNumElements();
8759 SDValue N0 = N->getOperand(0);
8760 SDValue N1 = N->getOperand(1);
8762 assert(N0.getValueType() == VT && "Vector shuffle must be normalized in DAG");
8764 // Canonicalize shuffle undef, undef -> undef
8765 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
8766 return DAG.getUNDEF(VT);
8768 ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
8770 // Canonicalize shuffle v, v -> v, undef
8772 SmallVector<int, 8> NewMask;
8773 for (unsigned i = 0; i != NumElts; ++i) {
8774 int Idx = SVN->getMaskElt(i);
8775 if (Idx >= (int)NumElts) Idx -= NumElts;
8776 NewMask.push_back(Idx);
8778 return DAG.getVectorShuffle(VT, N->getDebugLoc(), N0, DAG.getUNDEF(VT),
8782 // Canonicalize shuffle undef, v -> v, undef. Commute the shuffle mask.
8783 if (N0.getOpcode() == ISD::UNDEF) {
8784 SmallVector<int, 8> NewMask;
8785 for (unsigned i = 0; i != NumElts; ++i) {
8786 int Idx = SVN->getMaskElt(i);
8788 if (Idx < (int)NumElts)
8793 NewMask.push_back(Idx);
8795 return DAG.getVectorShuffle(VT, N->getDebugLoc(), N1, DAG.getUNDEF(VT),
8799 // Remove references to rhs if it is undef
8800 if (N1.getOpcode() == ISD::UNDEF) {
8801 bool Changed = false;
8802 SmallVector<int, 8> NewMask;
8803 for (unsigned i = 0; i != NumElts; ++i) {
8804 int Idx = SVN->getMaskElt(i);
8805 if (Idx >= (int)NumElts) {
8809 NewMask.push_back(Idx);
8812 return DAG.getVectorShuffle(VT, N->getDebugLoc(), N0, N1, &NewMask[0]);
8815 // If it is a splat, check if the argument vector is another splat or a
8816 // build_vector with all scalar elements the same.
8817 if (SVN->isSplat() && SVN->getSplatIndex() < (int)NumElts) {
8818 SDNode *V = N0.getNode();
8820 // If this is a bit convert that changes the element type of the vector but
8821 // not the number of vector elements, look through it. Be careful not to
8822 // look though conversions that change things like v4f32 to v2f64.
8823 if (V->getOpcode() == ISD::BITCAST) {
8824 SDValue ConvInput = V->getOperand(0);
8825 if (ConvInput.getValueType().isVector() &&
8826 ConvInput.getValueType().getVectorNumElements() == NumElts)
8827 V = ConvInput.getNode();
8830 if (V->getOpcode() == ISD::BUILD_VECTOR) {
8831 assert(V->getNumOperands() == NumElts &&
8832 "BUILD_VECTOR has wrong number of operands");
8834 bool AllSame = true;
8835 for (unsigned i = 0; i != NumElts; ++i) {
8836 if (V->getOperand(i).getOpcode() != ISD::UNDEF) {
8837 Base = V->getOperand(i);
8841 // Splat of <u, u, u, u>, return <u, u, u, u>
8842 if (!Base.getNode())
8844 for (unsigned i = 0; i != NumElts; ++i) {
8845 if (V->getOperand(i) != Base) {
8850 // Splat of <x, x, x, x>, return <x, x, x, x>
8856 // If this shuffle node is simply a swizzle of another shuffle node,
8857 // and it reverses the swizzle of the previous shuffle then we can
8858 // optimize shuffle(shuffle(x, undef), undef) -> x.
8859 if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
8860 N1.getOpcode() == ISD::UNDEF) {
8862 ShuffleVectorSDNode *OtherSV = cast<ShuffleVectorSDNode>(N0);
8864 // Shuffle nodes can only reverse shuffles with a single non-undef value.
8865 if (N0.getOperand(1).getOpcode() != ISD::UNDEF)
8868 // The incoming shuffle must be of the same type as the result of the
8870 assert(OtherSV->getOperand(0).getValueType() == VT &&
8871 "Shuffle types don't match");
8873 for (unsigned i = 0; i != NumElts; ++i) {
8874 int Idx = SVN->getMaskElt(i);
8875 assert(Idx < (int)NumElts && "Index references undef operand");
8876 // Next, this index comes from the first value, which is the incoming
8877 // shuffle. Adopt the incoming index.
8879 Idx = OtherSV->getMaskElt(Idx);
8881 // The combined shuffle must map each index to itself.
8882 if (Idx >= 0 && (unsigned)Idx != i)
8886 return OtherSV->getOperand(0);
8892 SDValue DAGCombiner::visitMEMBARRIER(SDNode* N) {
8893 if (!TLI.getShouldFoldAtomicFences())
8896 SDValue atomic = N->getOperand(0);
8897 switch (atomic.getOpcode()) {
8898 case ISD::ATOMIC_CMP_SWAP:
8899 case ISD::ATOMIC_SWAP:
8900 case ISD::ATOMIC_LOAD_ADD:
8901 case ISD::ATOMIC_LOAD_SUB:
8902 case ISD::ATOMIC_LOAD_AND:
8903 case ISD::ATOMIC_LOAD_OR:
8904 case ISD::ATOMIC_LOAD_XOR:
8905 case ISD::ATOMIC_LOAD_NAND:
8906 case ISD::ATOMIC_LOAD_MIN:
8907 case ISD::ATOMIC_LOAD_MAX:
8908 case ISD::ATOMIC_LOAD_UMIN:
8909 case ISD::ATOMIC_LOAD_UMAX:
8915 SDValue fence = atomic.getOperand(0);
8916 if (fence.getOpcode() != ISD::MEMBARRIER)
8919 switch (atomic.getOpcode()) {
8920 case ISD::ATOMIC_CMP_SWAP:
8921 return SDValue(DAG.UpdateNodeOperands(atomic.getNode(),
8922 fence.getOperand(0),
8923 atomic.getOperand(1), atomic.getOperand(2),
8924 atomic.getOperand(3)), atomic.getResNo());
8925 case ISD::ATOMIC_SWAP:
8926 case ISD::ATOMIC_LOAD_ADD:
8927 case ISD::ATOMIC_LOAD_SUB:
8928 case ISD::ATOMIC_LOAD_AND:
8929 case ISD::ATOMIC_LOAD_OR:
8930 case ISD::ATOMIC_LOAD_XOR:
8931 case ISD::ATOMIC_LOAD_NAND:
8932 case ISD::ATOMIC_LOAD_MIN:
8933 case ISD::ATOMIC_LOAD_MAX:
8934 case ISD::ATOMIC_LOAD_UMIN:
8935 case ISD::ATOMIC_LOAD_UMAX:
8936 return SDValue(DAG.UpdateNodeOperands(atomic.getNode(),
8937 fence.getOperand(0),
8938 atomic.getOperand(1), atomic.getOperand(2)),
8945 /// XformToShuffleWithZero - Returns a vector_shuffle if it able to transform
8946 /// an AND to a vector_shuffle with the destination vector and a zero vector.
8947 /// e.g. AND V, <0xffffffff, 0, 0xffffffff, 0>. ==>
8948 /// vector_shuffle V, Zero, <0, 4, 2, 4>
8949 SDValue DAGCombiner::XformToShuffleWithZero(SDNode *N) {
8950 EVT VT = N->getValueType(0);
8951 DebugLoc dl = N->getDebugLoc();
8952 SDValue LHS = N->getOperand(0);
8953 SDValue RHS = N->getOperand(1);
8954 if (N->getOpcode() == ISD::AND) {
8955 if (RHS.getOpcode() == ISD::BITCAST)
8956 RHS = RHS.getOperand(0);
8957 if (RHS.getOpcode() == ISD::BUILD_VECTOR) {
8958 SmallVector<int, 8> Indices;
8959 unsigned NumElts = RHS.getNumOperands();
8960 for (unsigned i = 0; i != NumElts; ++i) {
8961 SDValue Elt = RHS.getOperand(i);
8962 if (!isa<ConstantSDNode>(Elt))
8965 if (cast<ConstantSDNode>(Elt)->isAllOnesValue())
8966 Indices.push_back(i);
8967 else if (cast<ConstantSDNode>(Elt)->isNullValue())
8968 Indices.push_back(NumElts);
8973 // Let's see if the target supports this vector_shuffle.
8974 EVT RVT = RHS.getValueType();
8975 if (!TLI.isVectorClearMaskLegal(Indices, RVT))
8978 // Return the new VECTOR_SHUFFLE node.
8979 EVT EltVT = RVT.getVectorElementType();
8980 SmallVector<SDValue,8> ZeroOps(RVT.getVectorNumElements(),
8981 DAG.getConstant(0, EltVT));
8982 SDValue Zero = DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(),
8983 RVT, &ZeroOps[0], ZeroOps.size());
8984 LHS = DAG.getNode(ISD::BITCAST, dl, RVT, LHS);
8985 SDValue Shuf = DAG.getVectorShuffle(RVT, dl, LHS, Zero, &Indices[0]);
8986 return DAG.getNode(ISD::BITCAST, dl, VT, Shuf);
8993 /// SimplifyVBinOp - Visit a binary vector operation, like ADD.
8994 SDValue DAGCombiner::SimplifyVBinOp(SDNode *N) {
8995 // After legalize, the target may be depending on adds and other
8996 // binary ops to provide legal ways to construct constants or other
8997 // things. Simplifying them may result in a loss of legality.
8998 if (LegalOperations) return SDValue();
9000 assert(N->getValueType(0).isVector() &&
9001 "SimplifyVBinOp only works on vectors!");
9003 SDValue LHS = N->getOperand(0);
9004 SDValue RHS = N->getOperand(1);
9005 SDValue Shuffle = XformToShuffleWithZero(N);
9006 if (Shuffle.getNode()) return Shuffle;
9008 // If the LHS and RHS are BUILD_VECTOR nodes, see if we can constant fold
9010 if (LHS.getOpcode() == ISD::BUILD_VECTOR &&
9011 RHS.getOpcode() == ISD::BUILD_VECTOR) {
9012 SmallVector<SDValue, 8> Ops;
9013 for (unsigned i = 0, e = LHS.getNumOperands(); i != e; ++i) {
9014 SDValue LHSOp = LHS.getOperand(i);
9015 SDValue RHSOp = RHS.getOperand(i);
9016 // If these two elements can't be folded, bail out.
9017 if ((LHSOp.getOpcode() != ISD::UNDEF &&
9018 LHSOp.getOpcode() != ISD::Constant &&
9019 LHSOp.getOpcode() != ISD::ConstantFP) ||
9020 (RHSOp.getOpcode() != ISD::UNDEF &&
9021 RHSOp.getOpcode() != ISD::Constant &&
9022 RHSOp.getOpcode() != ISD::ConstantFP))
9025 // Can't fold divide by zero.
9026 if (N->getOpcode() == ISD::SDIV || N->getOpcode() == ISD::UDIV ||
9027 N->getOpcode() == ISD::FDIV) {
9028 if ((RHSOp.getOpcode() == ISD::Constant &&
9029 cast<ConstantSDNode>(RHSOp.getNode())->isNullValue()) ||
9030 (RHSOp.getOpcode() == ISD::ConstantFP &&
9031 cast<ConstantFPSDNode>(RHSOp.getNode())->getValueAPF().isZero()))
9035 EVT VT = LHSOp.getValueType();
9036 EVT RVT = RHSOp.getValueType();
9038 // Integer BUILD_VECTOR operands may have types larger than the element
9039 // size (e.g., when the element type is not legal). Prior to type
9040 // legalization, the types may not match between the two BUILD_VECTORS.
9041 // Truncate one of the operands to make them match.
9042 if (RVT.getSizeInBits() > VT.getSizeInBits()) {
9043 RHSOp = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, RHSOp);
9045 LHSOp = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), RVT, LHSOp);
9049 SDValue FoldOp = DAG.getNode(N->getOpcode(), LHS.getDebugLoc(), VT,
9051 if (FoldOp.getOpcode() != ISD::UNDEF &&
9052 FoldOp.getOpcode() != ISD::Constant &&
9053 FoldOp.getOpcode() != ISD::ConstantFP)
9055 Ops.push_back(FoldOp);
9056 AddToWorkList(FoldOp.getNode());
9059 if (Ops.size() == LHS.getNumOperands())
9060 return DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(),
9061 LHS.getValueType(), &Ops[0], Ops.size());
9067 /// SimplifyVUnaryOp - Visit a binary vector operation, like FABS/FNEG.
9068 SDValue DAGCombiner::SimplifyVUnaryOp(SDNode *N) {
9069 // After legalize, the target may be depending on adds and other
9070 // binary ops to provide legal ways to construct constants or other
9071 // things. Simplifying them may result in a loss of legality.
9072 if (LegalOperations) return SDValue();
9074 assert(N->getValueType(0).isVector() &&
9075 "SimplifyVUnaryOp only works on vectors!");
9077 SDValue N0 = N->getOperand(0);
9079 if (N0.getOpcode() != ISD::BUILD_VECTOR)
9082 // Operand is a BUILD_VECTOR node, see if we can constant fold it.
9083 SmallVector<SDValue, 8> Ops;
9084 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i) {
9085 SDValue Op = N0.getOperand(i);
9086 if (Op.getOpcode() != ISD::UNDEF &&
9087 Op.getOpcode() != ISD::ConstantFP)
9089 EVT EltVT = Op.getValueType();
9090 SDValue FoldOp = DAG.getNode(N->getOpcode(), N0.getDebugLoc(), EltVT, Op);
9091 if (FoldOp.getOpcode() != ISD::UNDEF &&
9092 FoldOp.getOpcode() != ISD::ConstantFP)
9094 Ops.push_back(FoldOp);
9095 AddToWorkList(FoldOp.getNode());
9098 if (Ops.size() != N0.getNumOperands())
9101 return DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(),
9102 N0.getValueType(), &Ops[0], Ops.size());
9105 SDValue DAGCombiner::SimplifySelect(DebugLoc DL, SDValue N0,
9106 SDValue N1, SDValue N2){
9107 assert(N0.getOpcode() ==ISD::SETCC && "First argument must be a SetCC node!");
9109 SDValue SCC = SimplifySelectCC(DL, N0.getOperand(0), N0.getOperand(1), N1, N2,
9110 cast<CondCodeSDNode>(N0.getOperand(2))->get());
9112 // If we got a simplified select_cc node back from SimplifySelectCC, then
9113 // break it down into a new SETCC node, and a new SELECT node, and then return
9114 // the SELECT node, since we were called with a SELECT node.
9115 if (SCC.getNode()) {
9116 // Check to see if we got a select_cc back (to turn into setcc/select).
9117 // Otherwise, just return whatever node we got back, like fabs.
9118 if (SCC.getOpcode() == ISD::SELECT_CC) {
9119 SDValue SETCC = DAG.getNode(ISD::SETCC, N0.getDebugLoc(),
9121 SCC.getOperand(0), SCC.getOperand(1),
9123 AddToWorkList(SETCC.getNode());
9124 return DAG.getNode(ISD::SELECT, SCC.getDebugLoc(), SCC.getValueType(),
9125 SCC.getOperand(2), SCC.getOperand(3), SETCC);
9133 /// SimplifySelectOps - Given a SELECT or a SELECT_CC node, where LHS and RHS
9134 /// are the two values being selected between, see if we can simplify the
9135 /// select. Callers of this should assume that TheSelect is deleted if this
9136 /// returns true. As such, they should return the appropriate thing (e.g. the
9137 /// node) back to the top-level of the DAG combiner loop to avoid it being
9139 bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS,
9142 // Cannot simplify select with vector condition
9143 if (TheSelect->getOperand(0).getValueType().isVector()) return false;
9145 // If this is a select from two identical things, try to pull the operation
9146 // through the select.
9147 if (LHS.getOpcode() != RHS.getOpcode() ||
9148 !LHS.hasOneUse() || !RHS.hasOneUse())
9151 // If this is a load and the token chain is identical, replace the select
9152 // of two loads with a load through a select of the address to load from.
9153 // This triggers in things like "select bool X, 10.0, 123.0" after the FP
9154 // constants have been dropped into the constant pool.
9155 if (LHS.getOpcode() == ISD::LOAD) {
9156 LoadSDNode *LLD = cast<LoadSDNode>(LHS);
9157 LoadSDNode *RLD = cast<LoadSDNode>(RHS);
9159 // Token chains must be identical.
9160 if (LHS.getOperand(0) != RHS.getOperand(0) ||
9161 // Do not let this transformation reduce the number of volatile loads.
9162 LLD->isVolatile() || RLD->isVolatile() ||
9163 // If this is an EXTLOAD, the VT's must match.
9164 LLD->getMemoryVT() != RLD->getMemoryVT() ||
9165 // If this is an EXTLOAD, the kind of extension must match.
9166 (LLD->getExtensionType() != RLD->getExtensionType() &&
9167 // The only exception is if one of the extensions is anyext.
9168 LLD->getExtensionType() != ISD::EXTLOAD &&
9169 RLD->getExtensionType() != ISD::EXTLOAD) ||
9170 // FIXME: this discards src value information. This is
9171 // over-conservative. It would be beneficial to be able to remember
9172 // both potential memory locations. Since we are discarding
9173 // src value info, don't do the transformation if the memory
9174 // locations are not in the default address space.
9175 LLD->getPointerInfo().getAddrSpace() != 0 ||
9176 RLD->getPointerInfo().getAddrSpace() != 0)
9179 // Check that the select condition doesn't reach either load. If so,
9180 // folding this will induce a cycle into the DAG. If not, this is safe to
9181 // xform, so create a select of the addresses.
9183 if (TheSelect->getOpcode() == ISD::SELECT) {
9184 SDNode *CondNode = TheSelect->getOperand(0).getNode();
9185 if ((LLD->hasAnyUseOfValue(1) && LLD->isPredecessorOf(CondNode)) ||
9186 (RLD->hasAnyUseOfValue(1) && RLD->isPredecessorOf(CondNode)))
9188 // The loads must not depend on one another.
9189 if (LLD->isPredecessorOf(RLD) ||
9190 RLD->isPredecessorOf(LLD))
9192 Addr = DAG.getNode(ISD::SELECT, TheSelect->getDebugLoc(),
9193 LLD->getBasePtr().getValueType(),
9194 TheSelect->getOperand(0), LLD->getBasePtr(),
9196 } else { // Otherwise SELECT_CC
9197 SDNode *CondLHS = TheSelect->getOperand(0).getNode();
9198 SDNode *CondRHS = TheSelect->getOperand(1).getNode();
9200 if ((LLD->hasAnyUseOfValue(1) &&
9201 (LLD->isPredecessorOf(CondLHS) || LLD->isPredecessorOf(CondRHS))) ||
9202 (RLD->hasAnyUseOfValue(1) &&
9203 (RLD->isPredecessorOf(CondLHS) || RLD->isPredecessorOf(CondRHS))))
9206 Addr = DAG.getNode(ISD::SELECT_CC, TheSelect->getDebugLoc(),
9207 LLD->getBasePtr().getValueType(),
9208 TheSelect->getOperand(0),
9209 TheSelect->getOperand(1),
9210 LLD->getBasePtr(), RLD->getBasePtr(),
9211 TheSelect->getOperand(4));
9215 if (LLD->getExtensionType() == ISD::NON_EXTLOAD) {
9216 Load = DAG.getLoad(TheSelect->getValueType(0),
9217 TheSelect->getDebugLoc(),
9218 // FIXME: Discards pointer info.
9219 LLD->getChain(), Addr, MachinePointerInfo(),
9220 LLD->isVolatile(), LLD->isNonTemporal(),
9221 LLD->isInvariant(), LLD->getAlignment());
9223 Load = DAG.getExtLoad(LLD->getExtensionType() == ISD::EXTLOAD ?
9224 RLD->getExtensionType() : LLD->getExtensionType(),
9225 TheSelect->getDebugLoc(),
9226 TheSelect->getValueType(0),
9227 // FIXME: Discards pointer info.
9228 LLD->getChain(), Addr, MachinePointerInfo(),
9229 LLD->getMemoryVT(), LLD->isVolatile(),
9230 LLD->isNonTemporal(), LLD->getAlignment());
9233 // Users of the select now use the result of the load.
9234 CombineTo(TheSelect, Load);
9236 // Users of the old loads now use the new load's chain. We know the
9237 // old-load value is dead now.
9238 CombineTo(LHS.getNode(), Load.getValue(0), Load.getValue(1));
9239 CombineTo(RHS.getNode(), Load.getValue(0), Load.getValue(1));
9246 /// SimplifySelectCC - Simplify an expression of the form (N0 cond N1) ? N2 : N3
9247 /// where 'cond' is the comparison specified by CC.
9248 SDValue DAGCombiner::SimplifySelectCC(DebugLoc DL, SDValue N0, SDValue N1,
9249 SDValue N2, SDValue N3,
9250 ISD::CondCode CC, bool NotExtCompare) {
9251 // (x ? y : y) -> y.
9252 if (N2 == N3) return N2;
9254 EVT VT = N2.getValueType();
9255 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
9256 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.getNode());
9257 ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N3.getNode());
9259 // Determine if the condition we're dealing with is constant
9260 SDValue SCC = SimplifySetCC(TLI.getSetCCResultType(N0.getValueType()),
9261 N0, N1, CC, DL, false);
9262 if (SCC.getNode()) AddToWorkList(SCC.getNode());
9263 ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.getNode());
9265 // fold select_cc true, x, y -> x
9266 if (SCCC && !SCCC->isNullValue())
9268 // fold select_cc false, x, y -> y
9269 if (SCCC && SCCC->isNullValue())
9272 // Check to see if we can simplify the select into an fabs node
9273 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1)) {
9274 // Allow either -0.0 or 0.0
9275 if (CFP->getValueAPF().isZero()) {
9276 // select (setg[te] X, +/-0.0), X, fneg(X) -> fabs
9277 if ((CC == ISD::SETGE || CC == ISD::SETGT) &&
9278 N0 == N2 && N3.getOpcode() == ISD::FNEG &&
9279 N2 == N3.getOperand(0))
9280 return DAG.getNode(ISD::FABS, DL, VT, N0);
9282 // select (setl[te] X, +/-0.0), fneg(X), X -> fabs
9283 if ((CC == ISD::SETLT || CC == ISD::SETLE) &&
9284 N0 == N3 && N2.getOpcode() == ISD::FNEG &&
9285 N2.getOperand(0) == N3)
9286 return DAG.getNode(ISD::FABS, DL, VT, N3);
9290 // Turn "(a cond b) ? 1.0f : 2.0f" into "load (tmp + ((a cond b) ? 0 : 4)"
9291 // where "tmp" is a constant pool entry containing an array with 1.0 and 2.0
9292 // in it. This is a win when the constant is not otherwise available because
9293 // it replaces two constant pool loads with one. We only do this if the FP
9294 // type is known to be legal, because if it isn't, then we are before legalize
9295 // types an we want the other legalization to happen first (e.g. to avoid
9296 // messing with soft float) and if the ConstantFP is not legal, because if
9297 // it is legal, we may not need to store the FP constant in a constant pool.
9298 if (ConstantFPSDNode *TV = dyn_cast<ConstantFPSDNode>(N2))
9299 if (ConstantFPSDNode *FV = dyn_cast<ConstantFPSDNode>(N3)) {
9300 if (TLI.isTypeLegal(N2.getValueType()) &&
9301 (TLI.getOperationAction(ISD::ConstantFP, N2.getValueType()) !=
9302 TargetLowering::Legal) &&
9303 // If both constants have multiple uses, then we won't need to do an
9304 // extra load, they are likely around in registers for other users.
9305 (TV->hasOneUse() || FV->hasOneUse())) {
9306 Constant *Elts[] = {
9307 const_cast<ConstantFP*>(FV->getConstantFPValue()),
9308 const_cast<ConstantFP*>(TV->getConstantFPValue())
9310 Type *FPTy = Elts[0]->getType();
9311 const DataLayout &TD = *TLI.getDataLayout();
9313 // Create a ConstantArray of the two constants.
9314 Constant *CA = ConstantArray::get(ArrayType::get(FPTy, 2), Elts);
9315 SDValue CPIdx = DAG.getConstantPool(CA, TLI.getPointerTy(),
9316 TD.getPrefTypeAlignment(FPTy));
9317 unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
9319 // Get the offsets to the 0 and 1 element of the array so that we can
9320 // select between them.
9321 SDValue Zero = DAG.getIntPtrConstant(0);
9322 unsigned EltSize = (unsigned)TD.getTypeAllocSize(Elts[0]->getType());
9323 SDValue One = DAG.getIntPtrConstant(EltSize);
9325 SDValue Cond = DAG.getSetCC(DL,
9326 TLI.getSetCCResultType(N0.getValueType()),
9328 AddToWorkList(Cond.getNode());
9329 SDValue CstOffset = DAG.getNode(ISD::SELECT, DL, Zero.getValueType(),
9331 AddToWorkList(CstOffset.getNode());
9332 CPIdx = DAG.getNode(ISD::ADD, DL, TLI.getPointerTy(), CPIdx,
9334 AddToWorkList(CPIdx.getNode());
9335 return DAG.getLoad(TV->getValueType(0), DL, DAG.getEntryNode(), CPIdx,
9336 MachinePointerInfo::getConstantPool(), false,
9337 false, false, Alignment);
9342 // Check to see if we can perform the "gzip trick", transforming
9343 // (select_cc setlt X, 0, A, 0) -> (and (sra X, (sub size(X), 1), A)
9344 if (N1C && N3C && N3C->isNullValue() && CC == ISD::SETLT &&
9345 (N1C->isNullValue() || // (a < 0) ? b : 0
9346 (N1C->getAPIntValue() == 1 && N0 == N2))) { // (a < 1) ? a : 0
9347 EVT XType = N0.getValueType();
9348 EVT AType = N2.getValueType();
9349 if (XType.bitsGE(AType)) {
9350 // and (sra X, size(X)-1, A) -> "and (srl X, C2), A" iff A is a
9351 // single-bit constant.
9352 if (N2C && ((N2C->getAPIntValue() & (N2C->getAPIntValue()-1)) == 0)) {
9353 unsigned ShCtV = N2C->getAPIntValue().logBase2();
9354 ShCtV = XType.getSizeInBits()-ShCtV-1;
9355 SDValue ShCt = DAG.getConstant(ShCtV,
9356 getShiftAmountTy(N0.getValueType()));
9357 SDValue Shift = DAG.getNode(ISD::SRL, N0.getDebugLoc(),
9359 AddToWorkList(Shift.getNode());
9361 if (XType.bitsGT(AType)) {
9362 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
9363 AddToWorkList(Shift.getNode());
9366 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
9369 SDValue Shift = DAG.getNode(ISD::SRA, N0.getDebugLoc(),
9371 DAG.getConstant(XType.getSizeInBits()-1,
9372 getShiftAmountTy(N0.getValueType())));
9373 AddToWorkList(Shift.getNode());
9375 if (XType.bitsGT(AType)) {
9376 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
9377 AddToWorkList(Shift.getNode());
9380 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
9384 // fold (select_cc seteq (and x, y), 0, 0, A) -> (and (shr (shl x)) A)
9385 // where y is has a single bit set.
9386 // A plaintext description would be, we can turn the SELECT_CC into an AND
9387 // when the condition can be materialized as an all-ones register. Any
9388 // single bit-test can be materialized as an all-ones register with
9389 // shift-left and shift-right-arith.
9390 if (CC == ISD::SETEQ && N0->getOpcode() == ISD::AND &&
9391 N0->getValueType(0) == VT &&
9392 N1C && N1C->isNullValue() &&
9393 N2C && N2C->isNullValue()) {
9394 SDValue AndLHS = N0->getOperand(0);
9395 ConstantSDNode *ConstAndRHS = dyn_cast<ConstantSDNode>(N0->getOperand(1));
9396 if (ConstAndRHS && ConstAndRHS->getAPIntValue().countPopulation() == 1) {
9397 // Shift the tested bit over the sign bit.
9398 APInt AndMask = ConstAndRHS->getAPIntValue();
9400 DAG.getConstant(AndMask.countLeadingZeros(),
9401 getShiftAmountTy(AndLHS.getValueType()));
9402 SDValue Shl = DAG.getNode(ISD::SHL, N0.getDebugLoc(), VT, AndLHS, ShlAmt);
9404 // Now arithmetic right shift it all the way over, so the result is either
9405 // all-ones, or zero.
9407 DAG.getConstant(AndMask.getBitWidth()-1,
9408 getShiftAmountTy(Shl.getValueType()));
9409 SDValue Shr = DAG.getNode(ISD::SRA, N0.getDebugLoc(), VT, Shl, ShrAmt);
9411 return DAG.getNode(ISD::AND, DL, VT, Shr, N3);
9415 // fold select C, 16, 0 -> shl C, 4
9416 if (N2C && N3C && N3C->isNullValue() && N2C->getAPIntValue().isPowerOf2() &&
9417 TLI.getBooleanContents(N0.getValueType().isVector()) ==
9418 TargetLowering::ZeroOrOneBooleanContent) {
9420 // If the caller doesn't want us to simplify this into a zext of a compare,
9422 if (NotExtCompare && N2C->getAPIntValue() == 1)
9425 // Get a SetCC of the condition
9426 // NOTE: Don't create a SETCC if it's not legal on this target.
9427 if (!LegalOperations ||
9428 TLI.isOperationLegal(ISD::SETCC,
9429 LegalTypes ? TLI.getSetCCResultType(N0.getValueType()) : MVT::i1)) {
9431 // cast from setcc result type to select result type
9433 SCC = DAG.getSetCC(DL, TLI.getSetCCResultType(N0.getValueType()),
9435 if (N2.getValueType().bitsLT(SCC.getValueType()))
9436 Temp = DAG.getZeroExtendInReg(SCC, N2.getDebugLoc(),
9439 Temp = DAG.getNode(ISD::ZERO_EXTEND, N2.getDebugLoc(),
9440 N2.getValueType(), SCC);
9442 SCC = DAG.getSetCC(N0.getDebugLoc(), MVT::i1, N0, N1, CC);
9443 Temp = DAG.getNode(ISD::ZERO_EXTEND, N2.getDebugLoc(),
9444 N2.getValueType(), SCC);
9447 AddToWorkList(SCC.getNode());
9448 AddToWorkList(Temp.getNode());
9450 if (N2C->getAPIntValue() == 1)
9453 // shl setcc result by log2 n2c
9454 return DAG.getNode(ISD::SHL, DL, N2.getValueType(), Temp,
9455 DAG.getConstant(N2C->getAPIntValue().logBase2(),
9456 getShiftAmountTy(Temp.getValueType())));
9460 // Check to see if this is the equivalent of setcc
9461 // FIXME: Turn all of these into setcc if setcc if setcc is legal
9462 // otherwise, go ahead with the folds.
9463 if (0 && N3C && N3C->isNullValue() && N2C && (N2C->getAPIntValue() == 1ULL)) {
9464 EVT XType = N0.getValueType();
9465 if (!LegalOperations ||
9466 TLI.isOperationLegal(ISD::SETCC, TLI.getSetCCResultType(XType))) {
9467 SDValue Res = DAG.getSetCC(DL, TLI.getSetCCResultType(XType), N0, N1, CC);
9468 if (Res.getValueType() != VT)
9469 Res = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Res);
9473 // fold (seteq X, 0) -> (srl (ctlz X, log2(size(X))))
9474 if (N1C && N1C->isNullValue() && CC == ISD::SETEQ &&
9475 (!LegalOperations ||
9476 TLI.isOperationLegal(ISD::CTLZ, XType))) {
9477 SDValue Ctlz = DAG.getNode(ISD::CTLZ, N0.getDebugLoc(), XType, N0);
9478 return DAG.getNode(ISD::SRL, DL, XType, Ctlz,
9479 DAG.getConstant(Log2_32(XType.getSizeInBits()),
9480 getShiftAmountTy(Ctlz.getValueType())));
9482 // fold (setgt X, 0) -> (srl (and (-X, ~X), size(X)-1))
9483 if (N1C && N1C->isNullValue() && CC == ISD::SETGT) {
9484 SDValue NegN0 = DAG.getNode(ISD::SUB, N0.getDebugLoc(),
9485 XType, DAG.getConstant(0, XType), N0);
9486 SDValue NotN0 = DAG.getNOT(N0.getDebugLoc(), N0, XType);
9487 return DAG.getNode(ISD::SRL, DL, XType,
9488 DAG.getNode(ISD::AND, DL, XType, NegN0, NotN0),
9489 DAG.getConstant(XType.getSizeInBits()-1,
9490 getShiftAmountTy(XType)));
9492 // fold (setgt X, -1) -> (xor (srl (X, size(X)-1), 1))
9493 if (N1C && N1C->isAllOnesValue() && CC == ISD::SETGT) {
9494 SDValue Sign = DAG.getNode(ISD::SRL, N0.getDebugLoc(), XType, N0,
9495 DAG.getConstant(XType.getSizeInBits()-1,
9496 getShiftAmountTy(N0.getValueType())));
9497 return DAG.getNode(ISD::XOR, DL, XType, Sign, DAG.getConstant(1, XType));
9501 // Check to see if this is an integer abs.
9502 // select_cc setg[te] X, 0, X, -X ->
9503 // select_cc setgt X, -1, X, -X ->
9504 // select_cc setl[te] X, 0, -X, X ->
9505 // select_cc setlt X, 1, -X, X ->
9506 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
9508 ConstantSDNode *SubC = NULL;
9509 if (((N1C->isNullValue() && (CC == ISD::SETGT || CC == ISD::SETGE)) ||
9510 (N1C->isAllOnesValue() && CC == ISD::SETGT)) &&
9511 N0 == N2 && N3.getOpcode() == ISD::SUB && N0 == N3.getOperand(1))
9512 SubC = dyn_cast<ConstantSDNode>(N3.getOperand(0));
9513 else if (((N1C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE)) ||
9514 (N1C->isOne() && CC == ISD::SETLT)) &&
9515 N0 == N3 && N2.getOpcode() == ISD::SUB && N0 == N2.getOperand(1))
9516 SubC = dyn_cast<ConstantSDNode>(N2.getOperand(0));
9518 EVT XType = N0.getValueType();
9519 if (SubC && SubC->isNullValue() && XType.isInteger()) {
9520 SDValue Shift = DAG.getNode(ISD::SRA, N0.getDebugLoc(), XType,
9522 DAG.getConstant(XType.getSizeInBits()-1,
9523 getShiftAmountTy(N0.getValueType())));
9524 SDValue Add = DAG.getNode(ISD::ADD, N0.getDebugLoc(),
9526 AddToWorkList(Shift.getNode());
9527 AddToWorkList(Add.getNode());
9528 return DAG.getNode(ISD::XOR, DL, XType, Add, Shift);
9535 /// SimplifySetCC - This is a stub for TargetLowering::SimplifySetCC.
9536 SDValue DAGCombiner::SimplifySetCC(EVT VT, SDValue N0,
9537 SDValue N1, ISD::CondCode Cond,
9538 DebugLoc DL, bool foldBooleans) {
9539 TargetLowering::DAGCombinerInfo
9540 DagCombineInfo(DAG, !LegalTypes, !LegalOperations, false, this);
9541 return TLI.SimplifySetCC(VT, N0, N1, Cond, foldBooleans, DagCombineInfo, DL);
9544 /// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
9545 /// return a DAG expression to select that will generate the same value by
9546 /// multiplying by a magic number. See:
9547 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
9548 SDValue DAGCombiner::BuildSDIV(SDNode *N) {
9549 std::vector<SDNode*> Built;
9550 SDValue S = TLI.BuildSDIV(N, DAG, LegalOperations, &Built);
9552 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
9558 /// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant,
9559 /// return a DAG expression to select that will generate the same value by
9560 /// multiplying by a magic number. See:
9561 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
9562 SDValue DAGCombiner::BuildUDIV(SDNode *N) {
9563 std::vector<SDNode*> Built;
9564 SDValue S = TLI.BuildUDIV(N, DAG, LegalOperations, &Built);
9566 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
9572 /// FindBaseOffset - Return true if base is a frame index, which is known not
9573 // to alias with anything but itself. Provides base object and offset as
9575 static bool FindBaseOffset(SDValue Ptr, SDValue &Base, int64_t &Offset,
9576 const GlobalValue *&GV, const void *&CV) {
9577 // Assume it is a primitive operation.
9578 Base = Ptr; Offset = 0; GV = 0; CV = 0;
9580 // If it's an adding a simple constant then integrate the offset.
9581 if (Base.getOpcode() == ISD::ADD) {
9582 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Base.getOperand(1))) {
9583 Base = Base.getOperand(0);
9584 Offset += C->getZExtValue();
9588 // Return the underlying GlobalValue, and update the Offset. Return false
9589 // for GlobalAddressSDNode since the same GlobalAddress may be represented
9590 // by multiple nodes with different offsets.
9591 if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Base)) {
9592 GV = G->getGlobal();
9593 Offset += G->getOffset();
9597 // Return the underlying Constant value, and update the Offset. Return false
9598 // for ConstantSDNodes since the same constant pool entry may be represented
9599 // by multiple nodes with different offsets.
9600 if (ConstantPoolSDNode *C = dyn_cast<ConstantPoolSDNode>(Base)) {
9601 CV = C->isMachineConstantPoolEntry() ? (const void *)C->getMachineCPVal()
9602 : (const void *)C->getConstVal();
9603 Offset += C->getOffset();
9606 // If it's any of the following then it can't alias with anything but itself.
9607 return isa<FrameIndexSDNode>(Base);
9610 /// isAlias - Return true if there is any possibility that the two addresses
9612 bool DAGCombiner::isAlias(SDValue Ptr1, int64_t Size1,
9613 const Value *SrcValue1, int SrcValueOffset1,
9614 unsigned SrcValueAlign1,
9615 const MDNode *TBAAInfo1,
9616 SDValue Ptr2, int64_t Size2,
9617 const Value *SrcValue2, int SrcValueOffset2,
9618 unsigned SrcValueAlign2,
9619 const MDNode *TBAAInfo2) const {
9620 // If they are the same then they must be aliases.
9621 if (Ptr1 == Ptr2) return true;
9623 // Gather base node and offset information.
9624 SDValue Base1, Base2;
9625 int64_t Offset1, Offset2;
9626 const GlobalValue *GV1, *GV2;
9627 const void *CV1, *CV2;
9628 bool isFrameIndex1 = FindBaseOffset(Ptr1, Base1, Offset1, GV1, CV1);
9629 bool isFrameIndex2 = FindBaseOffset(Ptr2, Base2, Offset2, GV2, CV2);
9631 // If they have a same base address then check to see if they overlap.
9632 if (Base1 == Base2 || (GV1 && (GV1 == GV2)) || (CV1 && (CV1 == CV2)))
9633 return !((Offset1 + Size1) <= Offset2 || (Offset2 + Size2) <= Offset1);
9635 // It is possible for different frame indices to alias each other, mostly
9636 // when tail call optimization reuses return address slots for arguments.
9637 // To catch this case, look up the actual index of frame indices to compute
9638 // the real alias relationship.
9639 if (isFrameIndex1 && isFrameIndex2) {
9640 MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
9641 Offset1 += MFI->getObjectOffset(cast<FrameIndexSDNode>(Base1)->getIndex());
9642 Offset2 += MFI->getObjectOffset(cast<FrameIndexSDNode>(Base2)->getIndex());
9643 return !((Offset1 + Size1) <= Offset2 || (Offset2 + Size2) <= Offset1);
9646 // Otherwise, if we know what the bases are, and they aren't identical, then
9647 // we know they cannot alias.
9648 if ((isFrameIndex1 || CV1 || GV1) && (isFrameIndex2 || CV2 || GV2))
9651 // If we know required SrcValue1 and SrcValue2 have relatively large alignment
9652 // compared to the size and offset of the access, we may be able to prove they
9653 // do not alias. This check is conservative for now to catch cases created by
9654 // splitting vector types.
9655 if ((SrcValueAlign1 == SrcValueAlign2) &&
9656 (SrcValueOffset1 != SrcValueOffset2) &&
9657 (Size1 == Size2) && (SrcValueAlign1 > Size1)) {
9658 int64_t OffAlign1 = SrcValueOffset1 % SrcValueAlign1;
9659 int64_t OffAlign2 = SrcValueOffset2 % SrcValueAlign1;
9661 // There is no overlap between these relatively aligned accesses of similar
9662 // size, return no alias.
9663 if ((OffAlign1 + Size1) <= OffAlign2 || (OffAlign2 + Size2) <= OffAlign1)
9667 if (CombinerGlobalAA) {
9668 // Use alias analysis information.
9669 int64_t MinOffset = std::min(SrcValueOffset1, SrcValueOffset2);
9670 int64_t Overlap1 = Size1 + SrcValueOffset1 - MinOffset;
9671 int64_t Overlap2 = Size2 + SrcValueOffset2 - MinOffset;
9672 AliasAnalysis::AliasResult AAResult =
9673 AA.alias(AliasAnalysis::Location(SrcValue1, Overlap1, TBAAInfo1),
9674 AliasAnalysis::Location(SrcValue2, Overlap2, TBAAInfo2));
9675 if (AAResult == AliasAnalysis::NoAlias)
9679 // Otherwise we have to assume they alias.
9683 /// FindAliasInfo - Extracts the relevant alias information from the memory
9684 /// node. Returns true if the operand was a load.
9685 bool DAGCombiner::FindAliasInfo(SDNode *N,
9686 SDValue &Ptr, int64_t &Size,
9687 const Value *&SrcValue,
9688 int &SrcValueOffset,
9689 unsigned &SrcValueAlign,
9690 const MDNode *&TBAAInfo) const {
9691 LSBaseSDNode *LS = cast<LSBaseSDNode>(N);
9693 Ptr = LS->getBasePtr();
9694 Size = LS->getMemoryVT().getSizeInBits() >> 3;
9695 SrcValue = LS->getSrcValue();
9696 SrcValueOffset = LS->getSrcValueOffset();
9697 SrcValueAlign = LS->getOriginalAlignment();
9698 TBAAInfo = LS->getTBAAInfo();
9699 return isa<LoadSDNode>(LS);
9702 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
9703 /// looking for aliasing nodes and adding them to the Aliases vector.
9704 void DAGCombiner::GatherAllAliases(SDNode *N, SDValue OriginalChain,
9705 SmallVector<SDValue, 8> &Aliases) {
9706 SmallVector<SDValue, 8> Chains; // List of chains to visit.
9707 SmallPtrSet<SDNode *, 16> Visited; // Visited node set.
9709 // Get alias information for node.
9712 const Value *SrcValue;
9714 unsigned SrcValueAlign;
9715 const MDNode *SrcTBAAInfo;
9716 bool IsLoad = FindAliasInfo(N, Ptr, Size, SrcValue, SrcValueOffset,
9717 SrcValueAlign, SrcTBAAInfo);
9720 Chains.push_back(OriginalChain);
9723 // Look at each chain and determine if it is an alias. If so, add it to the
9724 // aliases list. If not, then continue up the chain looking for the next
9726 while (!Chains.empty()) {
9727 SDValue Chain = Chains.back();
9730 // For TokenFactor nodes, look at each operand and only continue up the
9731 // chain until we find two aliases. If we've seen two aliases, assume we'll
9732 // find more and revert to original chain since the xform is unlikely to be
9735 // FIXME: The depth check could be made to return the last non-aliasing
9736 // chain we found before we hit a tokenfactor rather than the original
9738 if (Depth > 6 || Aliases.size() == 2) {
9740 Aliases.push_back(OriginalChain);
9744 // Don't bother if we've been before.
9745 if (!Visited.insert(Chain.getNode()))
9748 switch (Chain.getOpcode()) {
9749 case ISD::EntryToken:
9750 // Entry token is ideal chain operand, but handled in FindBetterChain.
9755 // Get alias information for Chain.
9758 const Value *OpSrcValue;
9759 int OpSrcValueOffset;
9760 unsigned OpSrcValueAlign;
9761 const MDNode *OpSrcTBAAInfo;
9762 bool IsOpLoad = FindAliasInfo(Chain.getNode(), OpPtr, OpSize,
9763 OpSrcValue, OpSrcValueOffset,
9767 // If chain is alias then stop here.
9768 if (!(IsLoad && IsOpLoad) &&
9769 isAlias(Ptr, Size, SrcValue, SrcValueOffset, SrcValueAlign,
9771 OpPtr, OpSize, OpSrcValue, OpSrcValueOffset,
9772 OpSrcValueAlign, OpSrcTBAAInfo)) {
9773 Aliases.push_back(Chain);
9775 // Look further up the chain.
9776 Chains.push_back(Chain.getOperand(0));
9782 case ISD::TokenFactor:
9783 // We have to check each of the operands of the token factor for "small"
9784 // token factors, so we queue them up. Adding the operands to the queue
9785 // (stack) in reverse order maintains the original order and increases the
9786 // likelihood that getNode will find a matching token factor (CSE.)
9787 if (Chain.getNumOperands() > 16) {
9788 Aliases.push_back(Chain);
9791 for (unsigned n = Chain.getNumOperands(); n;)
9792 Chains.push_back(Chain.getOperand(--n));
9797 // For all other instructions we will just have to take what we can get.
9798 Aliases.push_back(Chain);
9804 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes, looking
9805 /// for a better chain (aliasing node.)
9806 SDValue DAGCombiner::FindBetterChain(SDNode *N, SDValue OldChain) {
9807 SmallVector<SDValue, 8> Aliases; // Ops for replacing token factor.
9809 // Accumulate all the aliases to this node.
9810 GatherAllAliases(N, OldChain, Aliases);
9812 // If no operands then chain to entry token.
9813 if (Aliases.size() == 0)
9814 return DAG.getEntryNode();
9816 // If a single operand then chain to it. We don't need to revisit it.
9817 if (Aliases.size() == 1)
9820 // Construct a custom tailored token factor.
9821 return DAG.getNode(ISD::TokenFactor, N->getDebugLoc(), MVT::Other,
9822 &Aliases[0], Aliases.size());
9825 // SelectionDAG::Combine - This is the entry point for the file.
9827 void SelectionDAG::Combine(CombineLevel Level, AliasAnalysis &AA,
9828 CodeGenOpt::Level OptLevel) {
9829 /// run - This is the main entry point to this class.
9831 DAGCombiner(*this, AA, OptLevel).Run(Level);