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 //===----------------------------------------------------------------------===//
15 #define DEBUG_TYPE "dagcombine"
16 #include "llvm/CodeGen/SelectionDAG.h"
17 #include "llvm/CodeGen/MachineFunction.h"
18 #include "llvm/CodeGen/MachineFrameInfo.h"
19 #include "llvm/Analysis/AliasAnalysis.h"
20 #include "llvm/Target/TargetData.h"
21 #include "llvm/Target/TargetFrameInfo.h"
22 #include "llvm/Target/TargetLowering.h"
23 #include "llvm/Target/TargetMachine.h"
24 #include "llvm/Target/TargetOptions.h"
25 #include "llvm/ADT/SmallPtrSet.h"
26 #include "llvm/ADT/Statistic.h"
27 #include "llvm/Support/Compiler.h"
28 #include "llvm/Support/CommandLine.h"
29 #include "llvm/Support/Debug.h"
30 #include "llvm/Support/MathExtras.h"
35 STATISTIC(NodesCombined , "Number of dag nodes combined");
36 STATISTIC(PreIndexedNodes , "Number of pre-indexed nodes created");
37 STATISTIC(PostIndexedNodes, "Number of post-indexed nodes created");
41 CombinerAA("combiner-alias-analysis", cl::Hidden,
42 cl::desc("Turn on alias analysis during testing"));
45 CombinerGlobalAA("combiner-global-alias-analysis", cl::Hidden,
46 cl::desc("Include global information in alias analysis"));
48 //------------------------------ DAGCombiner ---------------------------------//
50 class VISIBILITY_HIDDEN DAGCombiner {
52 const TargetLowering &TLI;
58 // Worklist of all of the nodes that need to be simplified.
59 std::vector<SDNode*> WorkList;
61 // AA - Used for DAG load/store alias analysis.
64 /// AddUsersToWorkList - When an instruction is simplified, add all users of
65 /// the instruction to the work lists because they might get more simplified
68 void AddUsersToWorkList(SDNode *N) {
69 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
74 /// visit - call the node-specific routine that knows how to fold each
75 /// particular type of node.
76 SDValue visit(SDNode *N);
79 /// AddToWorkList - Add to the work list making sure it's instance is at the
80 /// the back (next to be processed.)
81 void AddToWorkList(SDNode *N) {
82 removeFromWorkList(N);
83 WorkList.push_back(N);
86 /// removeFromWorkList - remove all instances of N from the worklist.
88 void removeFromWorkList(SDNode *N) {
89 WorkList.erase(std::remove(WorkList.begin(), WorkList.end(), N),
93 SDValue CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
96 SDValue CombineTo(SDNode *N, SDValue Res, bool AddTo = true) {
97 return CombineTo(N, &Res, 1, AddTo);
100 SDValue CombineTo(SDNode *N, SDValue Res0, SDValue Res1,
102 SDValue To[] = { Res0, Res1 };
103 return CombineTo(N, To, 2, AddTo);
106 void CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO);
110 /// SimplifyDemandedBits - Check the specified integer node value to see if
111 /// it can be simplified or if things it uses can be simplified by bit
112 /// propagation. If so, return true.
113 bool SimplifyDemandedBits(SDValue Op) {
114 APInt Demanded = APInt::getAllOnesValue(Op.getValueSizeInBits());
115 return SimplifyDemandedBits(Op, Demanded);
118 bool SimplifyDemandedBits(SDValue Op, const APInt &Demanded);
120 bool CombineToPreIndexedLoadStore(SDNode *N);
121 bool CombineToPostIndexedLoadStore(SDNode *N);
124 /// combine - call the node-specific routine that knows how to fold each
125 /// particular type of node. If that doesn't do anything, try the
126 /// target-specific DAG combines.
127 SDValue combine(SDNode *N);
129 // Visitation implementation - Implement dag node combining for different
130 // node types. The semantics are as follows:
132 // SDValue.getNode() == 0 - No change was made
133 // SDValue.getNode() == N - N was replaced, is dead and has been handled.
134 // otherwise - N should be replaced by the returned Operand.
136 SDValue visitTokenFactor(SDNode *N);
137 SDValue visitMERGE_VALUES(SDNode *N);
138 SDValue visitADD(SDNode *N);
139 SDValue visitSUB(SDNode *N);
140 SDValue visitADDC(SDNode *N);
141 SDValue visitADDE(SDNode *N);
142 SDValue visitMUL(SDNode *N);
143 SDValue visitSDIV(SDNode *N);
144 SDValue visitUDIV(SDNode *N);
145 SDValue visitSREM(SDNode *N);
146 SDValue visitUREM(SDNode *N);
147 SDValue visitMULHU(SDNode *N);
148 SDValue visitMULHS(SDNode *N);
149 SDValue visitSMUL_LOHI(SDNode *N);
150 SDValue visitUMUL_LOHI(SDNode *N);
151 SDValue visitSDIVREM(SDNode *N);
152 SDValue visitUDIVREM(SDNode *N);
153 SDValue visitAND(SDNode *N);
154 SDValue visitOR(SDNode *N);
155 SDValue visitXOR(SDNode *N);
156 SDValue SimplifyVBinOp(SDNode *N);
157 SDValue visitSHL(SDNode *N);
158 SDValue visitSRA(SDNode *N);
159 SDValue visitSRL(SDNode *N);
160 SDValue visitCTLZ(SDNode *N);
161 SDValue visitCTTZ(SDNode *N);
162 SDValue visitCTPOP(SDNode *N);
163 SDValue visitSELECT(SDNode *N);
164 SDValue visitSELECT_CC(SDNode *N);
165 SDValue visitSETCC(SDNode *N);
166 SDValue visitSIGN_EXTEND(SDNode *N);
167 SDValue visitZERO_EXTEND(SDNode *N);
168 SDValue visitANY_EXTEND(SDNode *N);
169 SDValue visitSIGN_EXTEND_INREG(SDNode *N);
170 SDValue visitTRUNCATE(SDNode *N);
171 SDValue visitBIT_CONVERT(SDNode *N);
172 SDValue visitBUILD_PAIR(SDNode *N);
173 SDValue visitFADD(SDNode *N);
174 SDValue visitFSUB(SDNode *N);
175 SDValue visitFMUL(SDNode *N);
176 SDValue visitFDIV(SDNode *N);
177 SDValue visitFREM(SDNode *N);
178 SDValue visitFCOPYSIGN(SDNode *N);
179 SDValue visitSINT_TO_FP(SDNode *N);
180 SDValue visitUINT_TO_FP(SDNode *N);
181 SDValue visitFP_TO_SINT(SDNode *N);
182 SDValue visitFP_TO_UINT(SDNode *N);
183 SDValue visitFP_ROUND(SDNode *N);
184 SDValue visitFP_ROUND_INREG(SDNode *N);
185 SDValue visitFP_EXTEND(SDNode *N);
186 SDValue visitFNEG(SDNode *N);
187 SDValue visitFABS(SDNode *N);
188 SDValue visitBRCOND(SDNode *N);
189 SDValue visitBR_CC(SDNode *N);
190 SDValue visitLOAD(SDNode *N);
191 SDValue visitSTORE(SDNode *N);
192 SDValue visitINSERT_VECTOR_ELT(SDNode *N);
193 SDValue visitEXTRACT_VECTOR_ELT(SDNode *N);
194 SDValue visitBUILD_VECTOR(SDNode *N);
195 SDValue visitCONCAT_VECTORS(SDNode *N);
196 SDValue visitVECTOR_SHUFFLE(SDNode *N);
198 SDValue XformToShuffleWithZero(SDNode *N);
199 SDValue ReassociateOps(unsigned Opc, DebugLoc DL, SDValue LHS, SDValue RHS);
201 SDValue visitShiftByConstant(SDNode *N, unsigned Amt);
203 bool SimplifySelectOps(SDNode *SELECT, SDValue LHS, SDValue RHS);
204 SDValue SimplifyBinOpWithSameOpcodeHands(SDNode *N);
205 SDValue SimplifySelect(DebugLoc DL, SDValue N0, SDValue N1, SDValue N2);
206 SDValue SimplifySelectCC(DebugLoc DL, SDValue N0, SDValue N1, SDValue N2,
207 SDValue N3, ISD::CondCode CC,
208 bool NotExtCompare = false);
209 SDValue SimplifySetCC(MVT VT, SDValue N0, SDValue N1, ISD::CondCode Cond,
210 DebugLoc DL, bool foldBooleans = true);
211 SDValue SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
213 SDValue CombineConsecutiveLoads(SDNode *N, MVT VT);
214 SDValue ConstantFoldBIT_CONVERTofBUILD_VECTOR(SDNode *, MVT);
215 SDValue BuildSDIV(SDNode *N);
216 SDValue BuildUDIV(SDNode *N);
217 SDNode *MatchRotate(SDValue LHS, SDValue RHS, DebugLoc DL);
218 SDValue ReduceLoadWidth(SDNode *N);
220 SDValue GetDemandedBits(SDValue V, const APInt &Mask);
222 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
223 /// looking for aliasing nodes and adding them to the Aliases vector.
224 void GatherAllAliases(SDNode *N, SDValue OriginalChain,
225 SmallVector<SDValue, 8> &Aliases);
227 /// isAlias - Return true if there is any possibility that the two addresses
229 bool isAlias(SDValue Ptr1, int64_t Size1,
230 const Value *SrcValue1, int SrcValueOffset1,
231 SDValue Ptr2, int64_t Size2,
232 const Value *SrcValue2, int SrcValueOffset2) const;
234 /// FindAliasInfo - Extracts the relevant alias information from the memory
235 /// node. Returns true if the operand was a load.
236 bool FindAliasInfo(SDNode *N,
237 SDValue &Ptr, int64_t &Size,
238 const Value *&SrcValue, int &SrcValueOffset) const;
240 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes,
241 /// looking for a better chain (aliasing node.)
242 SDValue FindBetterChain(SDNode *N, SDValue Chain);
244 /// getShiftAmountTy - Returns a type large enough to hold any valid
245 /// shift amount - before type legalization these can be huge.
246 MVT getShiftAmountTy() {
247 return LegalTypes ? TLI.getShiftAmountTy() : TLI.getPointerTy();
251 DAGCombiner(SelectionDAG &D, AliasAnalysis &A, bool fast)
253 TLI(D.getTargetLoweringInfo()),
255 LegalOperations(false),
260 /// Run - runs the dag combiner on all nodes in the work list
261 void Run(CombineLevel AtLevel);
267 /// WorkListRemover - This class is a DAGUpdateListener that removes any deleted
268 /// nodes from the worklist.
269 class VISIBILITY_HIDDEN WorkListRemover :
270 public SelectionDAG::DAGUpdateListener {
273 explicit WorkListRemover(DAGCombiner &dc) : DC(dc) {}
275 virtual void NodeDeleted(SDNode *N, SDNode *E) {
276 DC.removeFromWorkList(N);
279 virtual void NodeUpdated(SDNode *N) {
285 //===----------------------------------------------------------------------===//
286 // TargetLowering::DAGCombinerInfo implementation
287 //===----------------------------------------------------------------------===//
289 void TargetLowering::DAGCombinerInfo::AddToWorklist(SDNode *N) {
290 ((DAGCombiner*)DC)->AddToWorkList(N);
293 SDValue TargetLowering::DAGCombinerInfo::
294 CombineTo(SDNode *N, const std::vector<SDValue> &To) {
295 return ((DAGCombiner*)DC)->CombineTo(N, &To[0], To.size());
298 SDValue TargetLowering::DAGCombinerInfo::
299 CombineTo(SDNode *N, SDValue Res) {
300 return ((DAGCombiner*)DC)->CombineTo(N, Res);
304 SDValue TargetLowering::DAGCombinerInfo::
305 CombineTo(SDNode *N, SDValue Res0, SDValue Res1) {
306 return ((DAGCombiner*)DC)->CombineTo(N, Res0, Res1);
309 void TargetLowering::DAGCombinerInfo::
310 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
311 return ((DAGCombiner*)DC)->CommitTargetLoweringOpt(TLO);
314 //===----------------------------------------------------------------------===//
316 //===----------------------------------------------------------------------===//
318 /// isNegatibleForFree - Return 1 if we can compute the negated form of the
319 /// specified expression for the same cost as the expression itself, or 2 if we
320 /// can compute the negated form more cheaply than the expression itself.
321 static char isNegatibleForFree(SDValue Op, bool LegalOperations,
322 unsigned Depth = 0) {
323 // No compile time optimizations on this type.
324 if (Op.getValueType() == MVT::ppcf128)
327 // fneg is removable even if it has multiple uses.
328 if (Op.getOpcode() == ISD::FNEG) return 2;
330 // Don't allow anything with multiple uses.
331 if (!Op.hasOneUse()) return 0;
333 // Don't recurse exponentially.
334 if (Depth > 6) return 0;
336 switch (Op.getOpcode()) {
337 default: return false;
338 case ISD::ConstantFP:
339 // Don't invert constant FP values after legalize. The negated constant
340 // isn't necessarily legal.
341 return LegalOperations ? 0 : 1;
343 // FIXME: determine better conditions for this xform.
344 if (!UnsafeFPMath) return 0;
346 // fold (fsub (fadd A, B)) -> (fsub (fneg A), B)
347 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, Depth+1))
349 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
350 return isNegatibleForFree(Op.getOperand(1), LegalOperations, Depth+1);
352 // We can't turn -(A-B) into B-A when we honor signed zeros.
353 if (!UnsafeFPMath) return 0;
355 // fold (fneg (fsub A, B)) -> (fsub B, A)
360 if (HonorSignDependentRoundingFPMath()) return 0;
362 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y) or (fmul X, (fneg Y))
363 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, Depth+1))
366 return isNegatibleForFree(Op.getOperand(1), LegalOperations, Depth+1);
371 return isNegatibleForFree(Op.getOperand(0), LegalOperations, Depth+1);
375 /// GetNegatedExpression - If isNegatibleForFree returns true, this function
376 /// returns the newly negated expression.
377 static SDValue GetNegatedExpression(SDValue Op, SelectionDAG &DAG,
378 bool LegalOperations, unsigned Depth = 0) {
379 // fneg is removable even if it has multiple uses.
380 if (Op.getOpcode() == ISD::FNEG) return Op.getOperand(0);
382 // Don't allow anything with multiple uses.
383 assert(Op.hasOneUse() && "Unknown reuse!");
385 assert(Depth <= 6 && "GetNegatedExpression doesn't match isNegatibleForFree");
386 switch (Op.getOpcode()) {
387 default: assert(0 && "Unknown code");
388 case ISD::ConstantFP: {
389 APFloat V = cast<ConstantFPSDNode>(Op)->getValueAPF();
391 return DAG.getConstantFP(V, Op.getValueType());
394 // FIXME: determine better conditions for this xform.
395 assert(UnsafeFPMath);
397 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
398 if (isNegatibleForFree(Op.getOperand(0), LegalOperations, Depth+1))
399 return DAG.getNode(ISD::FSUB, Op.getDebugLoc(), Op.getValueType(),
400 GetNegatedExpression(Op.getOperand(0), DAG,
401 LegalOperations, Depth+1),
403 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
404 return DAG.getNode(ISD::FSUB, Op.getDebugLoc(), Op.getValueType(),
405 GetNegatedExpression(Op.getOperand(1), DAG,
406 LegalOperations, Depth+1),
409 // We can't turn -(A-B) into B-A when we honor signed zeros.
410 assert(UnsafeFPMath);
412 // fold (fneg (fsub 0, B)) -> B
413 if (ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(Op.getOperand(0)))
414 if (N0CFP->getValueAPF().isZero())
415 return Op.getOperand(1);
417 // fold (fneg (fsub A, B)) -> (fsub B, A)
418 return DAG.getNode(ISD::FSUB, Op.getDebugLoc(), Op.getValueType(),
419 Op.getOperand(1), Op.getOperand(0));
423 assert(!HonorSignDependentRoundingFPMath());
425 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y)
426 if (isNegatibleForFree(Op.getOperand(0), LegalOperations, Depth+1))
427 return DAG.getNode(Op.getOpcode(), Op.getDebugLoc(), Op.getValueType(),
428 GetNegatedExpression(Op.getOperand(0), DAG,
429 LegalOperations, Depth+1),
432 // fold (fneg (fmul X, Y)) -> (fmul X, (fneg Y))
433 return DAG.getNode(Op.getOpcode(), Op.getDebugLoc(), Op.getValueType(),
435 GetNegatedExpression(Op.getOperand(1), DAG,
436 LegalOperations, Depth+1));
440 return DAG.getNode(Op.getOpcode(), Op.getDebugLoc(), Op.getValueType(),
441 GetNegatedExpression(Op.getOperand(0), DAG,
442 LegalOperations, Depth+1));
444 return DAG.getNode(ISD::FP_ROUND, Op.getDebugLoc(), Op.getValueType(),
445 GetNegatedExpression(Op.getOperand(0), DAG,
446 LegalOperations, Depth+1),
452 // isSetCCEquivalent - Return true if this node is a setcc, or is a select_cc
453 // that selects between the values 1 and 0, making it equivalent to a setcc.
454 // Also, set the incoming LHS, RHS, and CC references to the appropriate
455 // nodes based on the type of node we are checking. This simplifies life a
456 // bit for the callers.
457 static bool isSetCCEquivalent(SDValue N, SDValue &LHS, SDValue &RHS,
459 if (N.getOpcode() == ISD::SETCC) {
460 LHS = N.getOperand(0);
461 RHS = N.getOperand(1);
462 CC = N.getOperand(2);
465 if (N.getOpcode() == ISD::SELECT_CC &&
466 N.getOperand(2).getOpcode() == ISD::Constant &&
467 N.getOperand(3).getOpcode() == ISD::Constant &&
468 cast<ConstantSDNode>(N.getOperand(2))->getAPIntValue() == 1 &&
469 cast<ConstantSDNode>(N.getOperand(3))->isNullValue()) {
470 LHS = N.getOperand(0);
471 RHS = N.getOperand(1);
472 CC = N.getOperand(4);
478 // isOneUseSetCC - Return true if this is a SetCC-equivalent operation with only
479 // one use. If this is true, it allows the users to invert the operation for
480 // free when it is profitable to do so.
481 static bool isOneUseSetCC(SDValue N) {
483 if (isSetCCEquivalent(N, N0, N1, N2) && N.getNode()->hasOneUse())
488 SDValue DAGCombiner::ReassociateOps(unsigned Opc, DebugLoc DL,
489 SDValue N0, SDValue N1) {
490 MVT VT = N0.getValueType();
491 if (N0.getOpcode() == Opc && isa<ConstantSDNode>(N0.getOperand(1))) {
492 if (isa<ConstantSDNode>(N1)) {
493 // reassoc. (op (op x, c1), c2) -> (op x, (op c1, c2))
495 DAG.FoldConstantArithmetic(Opc, VT,
496 cast<ConstantSDNode>(N0.getOperand(1)),
497 cast<ConstantSDNode>(N1));
498 return DAG.getNode(Opc, DL, VT, N0.getOperand(0), OpNode);
499 } else if (N0.hasOneUse()) {
500 // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one use
501 SDValue OpNode = DAG.getNode(Opc, N0.getDebugLoc(), VT,
502 N0.getOperand(0), N1);
503 AddToWorkList(OpNode.getNode());
504 return DAG.getNode(Opc, DL, VT, OpNode, N0.getOperand(1));
508 if (N1.getOpcode() == Opc && isa<ConstantSDNode>(N1.getOperand(1))) {
509 if (isa<ConstantSDNode>(N0)) {
510 // reassoc. (op c2, (op x, c1)) -> (op x, (op c1, c2))
512 DAG.FoldConstantArithmetic(Opc, VT,
513 cast<ConstantSDNode>(N1.getOperand(1)),
514 cast<ConstantSDNode>(N0));
515 return DAG.getNode(Opc, DL, VT, N1.getOperand(0), OpNode);
516 } else if (N1.hasOneUse()) {
517 // reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) iff x+c1 has one use
518 SDValue OpNode = DAG.getNode(Opc, N0.getDebugLoc(), VT,
519 N1.getOperand(0), N0);
520 AddToWorkList(OpNode.getNode());
521 return DAG.getNode(Opc, DL, VT, OpNode, N1.getOperand(1));
528 SDValue DAGCombiner::CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
530 assert(N->getNumValues() == NumTo && "Broken CombineTo call!");
532 DOUT << "\nReplacing.1 "; DEBUG(N->dump(&DAG));
533 DOUT << "\nWith: "; DEBUG(To[0].getNode()->dump(&DAG));
534 DOUT << " and " << NumTo-1 << " other values\n";
535 DEBUG(for (unsigned i = 0, e = NumTo; i != e; ++i)
536 assert(N->getValueType(i) == To[i].getValueType() &&
537 "Cannot combine value to value of different type!"));
538 WorkListRemover DeadNodes(*this);
539 DAG.ReplaceAllUsesWith(N, To, &DeadNodes);
542 // Push the new nodes and any users onto the worklist
543 for (unsigned i = 0, e = NumTo; i != e; ++i) {
544 AddToWorkList(To[i].getNode());
545 AddUsersToWorkList(To[i].getNode());
549 // Finally, if the node is now dead, remove it from the graph. The node
550 // may not be dead if the replacement process recursively simplified to
551 // something else needing this node.
552 if (N->use_empty()) {
553 // Nodes can be reintroduced into the worklist. Make sure we do not
554 // process a node that has been replaced.
555 removeFromWorkList(N);
557 // Finally, since the node is now dead, remove it from the graph.
560 return SDValue(N, 0);
564 DAGCombiner::CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &
566 // Replace all uses. If any nodes become isomorphic to other nodes and
567 // are deleted, make sure to remove them from our worklist.
568 WorkListRemover DeadNodes(*this);
569 DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New, &DeadNodes);
571 // Push the new node and any (possibly new) users onto the worklist.
572 AddToWorkList(TLO.New.getNode());
573 AddUsersToWorkList(TLO.New.getNode());
575 // Finally, if the node is now dead, remove it from the graph. The node
576 // may not be dead if the replacement process recursively simplified to
577 // something else needing this node.
578 if (TLO.Old.getNode()->use_empty()) {
579 removeFromWorkList(TLO.Old.getNode());
581 // If the operands of this node are only used by the node, they will now
582 // be dead. Make sure to visit them first to delete dead nodes early.
583 for (unsigned i = 0, e = TLO.Old.getNode()->getNumOperands(); i != e; ++i)
584 if (TLO.Old.getNode()->getOperand(i).getNode()->hasOneUse())
585 AddToWorkList(TLO.Old.getNode()->getOperand(i).getNode());
587 DAG.DeleteNode(TLO.Old.getNode());
591 /// SimplifyDemandedBits - Check the specified integer node value to see if
592 /// it can be simplified or if things it uses can be simplified by bit
593 /// propagation. If so, return true.
594 bool DAGCombiner::SimplifyDemandedBits(SDValue Op, const APInt &Demanded) {
595 TargetLowering::TargetLoweringOpt TLO(DAG);
596 APInt KnownZero, KnownOne;
597 if (!TLI.SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO))
601 AddToWorkList(Op.getNode());
603 // Replace the old value with the new one.
605 DOUT << "\nReplacing.2 "; DEBUG(TLO.Old.getNode()->dump(&DAG));
606 DOUT << "\nWith: "; DEBUG(TLO.New.getNode()->dump(&DAG));
609 CommitTargetLoweringOpt(TLO);
613 //===----------------------------------------------------------------------===//
614 // Main DAG Combiner implementation
615 //===----------------------------------------------------------------------===//
617 void DAGCombiner::Run(CombineLevel AtLevel) {
618 // set the instance variables, so that the various visit routines may use it.
620 LegalOperations = Level >= NoIllegalOperations;
621 LegalTypes = Level >= NoIllegalTypes;
623 // Add all the dag nodes to the worklist.
624 WorkList.reserve(DAG.allnodes_size());
625 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
626 E = DAG.allnodes_end(); I != E; ++I)
627 WorkList.push_back(I);
629 // Create a dummy node (which is not added to allnodes), that adds a reference
630 // to the root node, preventing it from being deleted, and tracking any
631 // changes of the root.
632 HandleSDNode Dummy(DAG.getRoot());
634 // The root of the dag may dangle to deleted nodes until the dag combiner is
635 // done. Set it to null to avoid confusion.
636 DAG.setRoot(SDValue());
638 // while the worklist isn't empty, inspect the node on the end of it and
639 // try and combine it.
640 while (!WorkList.empty()) {
641 SDNode *N = WorkList.back();
644 // If N has no uses, it is dead. Make sure to revisit all N's operands once
645 // N is deleted from the DAG, since they too may now be dead or may have a
646 // reduced number of uses, allowing other xforms.
647 if (N->use_empty() && N != &Dummy) {
648 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
649 AddToWorkList(N->getOperand(i).getNode());
655 SDValue RV = combine(N);
657 if (RV.getNode() == 0)
662 // If we get back the same node we passed in, rather than a new node or
663 // zero, we know that the node must have defined multiple values and
664 // CombineTo was used. Since CombineTo takes care of the worklist
665 // mechanics for us, we have no work to do in this case.
666 if (RV.getNode() == N)
669 assert(N->getOpcode() != ISD::DELETED_NODE &&
670 RV.getNode()->getOpcode() != ISD::DELETED_NODE &&
671 "Node was deleted but visit returned new node!");
673 DOUT << "\nReplacing.3 "; DEBUG(N->dump(&DAG));
674 DOUT << "\nWith: "; DEBUG(RV.getNode()->dump(&DAG));
676 WorkListRemover DeadNodes(*this);
677 if (N->getNumValues() == RV.getNode()->getNumValues())
678 DAG.ReplaceAllUsesWith(N, RV.getNode(), &DeadNodes);
680 assert(N->getValueType(0) == RV.getValueType() &&
681 N->getNumValues() == 1 && "Type mismatch");
683 DAG.ReplaceAllUsesWith(N, &OpV, &DeadNodes);
686 // Push the new node and any users onto the worklist
687 AddToWorkList(RV.getNode());
688 AddUsersToWorkList(RV.getNode());
690 // Add any uses of the old node to the worklist in case this node is the
691 // last one that uses them. They may become dead after this node is
693 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
694 AddToWorkList(N->getOperand(i).getNode());
696 // Finally, if the node is now dead, remove it from the graph. The node
697 // may not be dead if the replacement process recursively simplified to
698 // something else needing this node.
699 if (N->use_empty()) {
700 // Nodes can be reintroduced into the worklist. Make sure we do not
701 // process a node that has been replaced.
702 removeFromWorkList(N);
704 // Finally, since the node is now dead, remove it from the graph.
709 // If the root changed (e.g. it was a dead load, update the root).
710 DAG.setRoot(Dummy.getValue());
713 SDValue DAGCombiner::visit(SDNode *N) {
714 switch(N->getOpcode()) {
716 case ISD::TokenFactor: return visitTokenFactor(N);
717 case ISD::MERGE_VALUES: return visitMERGE_VALUES(N);
718 case ISD::ADD: return visitADD(N);
719 case ISD::SUB: return visitSUB(N);
720 case ISD::ADDC: return visitADDC(N);
721 case ISD::ADDE: return visitADDE(N);
722 case ISD::MUL: return visitMUL(N);
723 case ISD::SDIV: return visitSDIV(N);
724 case ISD::UDIV: return visitUDIV(N);
725 case ISD::SREM: return visitSREM(N);
726 case ISD::UREM: return visitUREM(N);
727 case ISD::MULHU: return visitMULHU(N);
728 case ISD::MULHS: return visitMULHS(N);
729 case ISD::SMUL_LOHI: return visitSMUL_LOHI(N);
730 case ISD::UMUL_LOHI: return visitUMUL_LOHI(N);
731 case ISD::SDIVREM: return visitSDIVREM(N);
732 case ISD::UDIVREM: return visitUDIVREM(N);
733 case ISD::AND: return visitAND(N);
734 case ISD::OR: return visitOR(N);
735 case ISD::XOR: return visitXOR(N);
736 case ISD::SHL: return visitSHL(N);
737 case ISD::SRA: return visitSRA(N);
738 case ISD::SRL: return visitSRL(N);
739 case ISD::CTLZ: return visitCTLZ(N);
740 case ISD::CTTZ: return visitCTTZ(N);
741 case ISD::CTPOP: return visitCTPOP(N);
742 case ISD::SELECT: return visitSELECT(N);
743 case ISD::SELECT_CC: return visitSELECT_CC(N);
744 case ISD::SETCC: return visitSETCC(N);
745 case ISD::SIGN_EXTEND: return visitSIGN_EXTEND(N);
746 case ISD::ZERO_EXTEND: return visitZERO_EXTEND(N);
747 case ISD::ANY_EXTEND: return visitANY_EXTEND(N);
748 case ISD::SIGN_EXTEND_INREG: return visitSIGN_EXTEND_INREG(N);
749 case ISD::TRUNCATE: return visitTRUNCATE(N);
750 case ISD::BIT_CONVERT: return visitBIT_CONVERT(N);
751 case ISD::BUILD_PAIR: return visitBUILD_PAIR(N);
752 case ISD::FADD: return visitFADD(N);
753 case ISD::FSUB: return visitFSUB(N);
754 case ISD::FMUL: return visitFMUL(N);
755 case ISD::FDIV: return visitFDIV(N);
756 case ISD::FREM: return visitFREM(N);
757 case ISD::FCOPYSIGN: return visitFCOPYSIGN(N);
758 case ISD::SINT_TO_FP: return visitSINT_TO_FP(N);
759 case ISD::UINT_TO_FP: return visitUINT_TO_FP(N);
760 case ISD::FP_TO_SINT: return visitFP_TO_SINT(N);
761 case ISD::FP_TO_UINT: return visitFP_TO_UINT(N);
762 case ISD::FP_ROUND: return visitFP_ROUND(N);
763 case ISD::FP_ROUND_INREG: return visitFP_ROUND_INREG(N);
764 case ISD::FP_EXTEND: return visitFP_EXTEND(N);
765 case ISD::FNEG: return visitFNEG(N);
766 case ISD::FABS: return visitFABS(N);
767 case ISD::BRCOND: return visitBRCOND(N);
768 case ISD::BR_CC: return visitBR_CC(N);
769 case ISD::LOAD: return visitLOAD(N);
770 case ISD::STORE: return visitSTORE(N);
771 case ISD::INSERT_VECTOR_ELT: return visitINSERT_VECTOR_ELT(N);
772 case ISD::EXTRACT_VECTOR_ELT: return visitEXTRACT_VECTOR_ELT(N);
773 case ISD::BUILD_VECTOR: return visitBUILD_VECTOR(N);
774 case ISD::CONCAT_VECTORS: return visitCONCAT_VECTORS(N);
775 case ISD::VECTOR_SHUFFLE: return visitVECTOR_SHUFFLE(N);
780 SDValue DAGCombiner::combine(SDNode *N) {
781 SDValue RV = visit(N);
783 // If nothing happened, try a target-specific DAG combine.
784 if (RV.getNode() == 0) {
785 assert(N->getOpcode() != ISD::DELETED_NODE &&
786 "Node was deleted but visit returned NULL!");
788 if (N->getOpcode() >= ISD::BUILTIN_OP_END ||
789 TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode())) {
791 // Expose the DAG combiner to the target combiner impls.
792 TargetLowering::DAGCombinerInfo
793 DagCombineInfo(DAG, Level == Unrestricted, false, this);
795 RV = TLI.PerformDAGCombine(N, DagCombineInfo);
799 // If N is a commutative binary node, try commuting it to enable more
801 if (RV.getNode() == 0 &&
802 SelectionDAG::isCommutativeBinOp(N->getOpcode()) &&
803 N->getNumValues() == 1) {
804 SDValue N0 = N->getOperand(0);
805 SDValue N1 = N->getOperand(1);
807 // Constant operands are canonicalized to RHS.
808 if (isa<ConstantSDNode>(N0) || !isa<ConstantSDNode>(N1)) {
809 SDValue Ops[] = { N1, N0 };
810 SDNode *CSENode = DAG.getNodeIfExists(N->getOpcode(), N->getVTList(),
813 return SDValue(CSENode, 0);
820 /// getInputChainForNode - Given a node, return its input chain if it has one,
821 /// otherwise return a null sd operand.
822 static SDValue getInputChainForNode(SDNode *N) {
823 if (unsigned NumOps = N->getNumOperands()) {
824 if (N->getOperand(0).getValueType() == MVT::Other)
825 return N->getOperand(0);
826 else if (N->getOperand(NumOps-1).getValueType() == MVT::Other)
827 return N->getOperand(NumOps-1);
828 for (unsigned i = 1; i < NumOps-1; ++i)
829 if (N->getOperand(i).getValueType() == MVT::Other)
830 return N->getOperand(i);
835 SDValue DAGCombiner::visitTokenFactor(SDNode *N) {
836 // If N has two operands, where one has an input chain equal to the other,
837 // the 'other' chain is redundant.
838 if (N->getNumOperands() == 2) {
839 if (getInputChainForNode(N->getOperand(0).getNode()) == N->getOperand(1))
840 return N->getOperand(0);
841 if (getInputChainForNode(N->getOperand(1).getNode()) == N->getOperand(0))
842 return N->getOperand(1);
845 SmallVector<SDNode *, 8> TFs; // List of token factors to visit.
846 SmallVector<SDValue, 8> Ops; // Ops for replacing token factor.
847 SmallPtrSet<SDNode*, 16> SeenOps;
848 bool Changed = false; // If we should replace this token factor.
850 // Start out with this token factor.
853 // Iterate through token factors. The TFs grows when new token factors are
855 for (unsigned i = 0; i < TFs.size(); ++i) {
858 // Check each of the operands.
859 for (unsigned i = 0, ie = TF->getNumOperands(); i != ie; ++i) {
860 SDValue Op = TF->getOperand(i);
862 switch (Op.getOpcode()) {
863 case ISD::EntryToken:
864 // Entry tokens don't need to be added to the list. They are
869 case ISD::TokenFactor:
870 if ((CombinerAA || Op.hasOneUse()) &&
871 std::find(TFs.begin(), TFs.end(), Op.getNode()) == TFs.end()) {
872 // Queue up for processing.
873 TFs.push_back(Op.getNode());
874 // Clean up in case the token factor is removed.
875 AddToWorkList(Op.getNode());
882 // Only add if it isn't already in the list.
883 if (SeenOps.insert(Op.getNode()))
894 // If we've change things around then replace token factor.
897 // The entry token is the only possible outcome.
898 Result = DAG.getEntryNode();
900 // New and improved token factor.
901 Result = DAG.getNode(ISD::TokenFactor, N->getDebugLoc(),
902 MVT::Other, &Ops[0], Ops.size());
905 // Don't add users to work list.
906 return CombineTo(N, Result, false);
912 /// MERGE_VALUES can always be eliminated.
913 SDValue DAGCombiner::visitMERGE_VALUES(SDNode *N) {
914 WorkListRemover DeadNodes(*this);
915 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
916 DAG.ReplaceAllUsesOfValueWith(SDValue(N, i), N->getOperand(i),
918 removeFromWorkList(N);
920 return SDValue(N, 0); // Return N so it doesn't get rechecked!
924 SDValue combineShlAddConstant(DebugLoc DL, SDValue N0, SDValue N1,
926 MVT VT = N0.getValueType();
927 SDValue N00 = N0.getOperand(0);
928 SDValue N01 = N0.getOperand(1);
929 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N01);
931 if (N01C && N00.getOpcode() == ISD::ADD && N00.getNode()->hasOneUse() &&
932 isa<ConstantSDNode>(N00.getOperand(1))) {
933 // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
934 N0 = DAG.getNode(ISD::ADD, N0.getDebugLoc(), VT,
935 DAG.getNode(ISD::SHL, N00.getDebugLoc(), VT,
936 N00.getOperand(0), N01),
937 DAG.getNode(ISD::SHL, N01.getDebugLoc(), VT,
938 N00.getOperand(1), N01));
939 return DAG.getNode(ISD::ADD, DL, VT, N0, N1);
946 SDValue combineSelectAndUse(SDNode *N, SDValue Slct, SDValue OtherOp,
947 SelectionDAG &DAG, const TargetLowering &TLI,
948 bool LegalOperations) {
949 MVT VT = N->getValueType(0);
950 unsigned Opc = N->getOpcode();
951 bool isSlctCC = Slct.getOpcode() == ISD::SELECT_CC;
952 SDValue LHS = isSlctCC ? Slct.getOperand(2) : Slct.getOperand(1);
953 SDValue RHS = isSlctCC ? Slct.getOperand(3) : Slct.getOperand(2);
954 ISD::CondCode CC = ISD::SETCC_INVALID;
957 CC = cast<CondCodeSDNode>(Slct.getOperand(4))->get();
959 SDValue CCOp = Slct.getOperand(0);
960 if (CCOp.getOpcode() == ISD::SETCC)
961 CC = cast<CondCodeSDNode>(CCOp.getOperand(2))->get();
964 bool DoXform = false;
966 assert ((Opc == ISD::ADD || (Opc == ISD::SUB && Slct == N->getOperand(1))) &&
969 if (LHS.getOpcode() == ISD::Constant &&
970 cast<ConstantSDNode>(LHS)->isNullValue()) {
972 } else if (CC != ISD::SETCC_INVALID &&
973 RHS.getOpcode() == ISD::Constant &&
974 cast<ConstantSDNode>(RHS)->isNullValue()) {
976 SDValue Op0 = Slct.getOperand(0);
977 MVT OpVT = isSlctCC ? Op0.getValueType() :
978 Op0.getOperand(0).getValueType();
979 bool isInt = OpVT.isInteger();
980 CC = ISD::getSetCCInverse(CC, isInt);
982 if (LegalOperations && !TLI.isCondCodeLegal(CC, OpVT))
983 return SDValue(); // Inverse operator isn't legal.
990 SDValue Result = DAG.getNode(Opc, RHS.getDebugLoc(), VT, OtherOp, RHS);
992 return DAG.getSelectCC(N->getDebugLoc(), OtherOp, Result,
993 Slct.getOperand(0), Slct.getOperand(1), CC);
994 SDValue CCOp = Slct.getOperand(0);
996 CCOp = DAG.getSetCC(Slct.getDebugLoc(), CCOp.getValueType(),
997 CCOp.getOperand(0), CCOp.getOperand(1), CC);
998 return DAG.getNode(ISD::SELECT, N->getDebugLoc(), VT,
999 CCOp, OtherOp, Result);
1004 SDValue DAGCombiner::visitADD(SDNode *N) {
1005 SDValue N0 = N->getOperand(0);
1006 SDValue N1 = N->getOperand(1);
1007 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1008 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1009 MVT VT = N0.getValueType();
1012 if (VT.isVector()) {
1013 SDValue FoldedVOp = SimplifyVBinOp(N);
1014 if (FoldedVOp.getNode()) return FoldedVOp;
1017 // fold (add x, undef) -> undef
1018 if (N0.getOpcode() == ISD::UNDEF)
1020 if (N1.getOpcode() == ISD::UNDEF)
1022 // fold (add c1, c2) -> c1+c2
1024 return DAG.FoldConstantArithmetic(ISD::ADD, VT, N0C, N1C);
1025 // canonicalize constant to RHS
1027 return DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N1, N0);
1028 // fold (add x, 0) -> x
1029 if (N1C && N1C->isNullValue())
1031 // fold (add Sym, c) -> Sym+c
1032 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1033 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA) && N1C &&
1034 GA->getOpcode() == ISD::GlobalAddress)
1035 return DAG.getGlobalAddress(GA->getGlobal(), VT,
1037 (uint64_t)N1C->getSExtValue());
1038 // fold ((c1-A)+c2) -> (c1+c2)-A
1039 if (N1C && N0.getOpcode() == ISD::SUB)
1040 if (ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getOperand(0)))
1041 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1042 DAG.getConstant(N1C->getAPIntValue()+
1043 N0C->getAPIntValue(), VT),
1046 SDValue RADD = ReassociateOps(ISD::ADD, N->getDebugLoc(), N0, N1);
1047 if (RADD.getNode() != 0)
1049 // fold ((0-A) + B) -> B-A
1050 if (N0.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N0.getOperand(0)) &&
1051 cast<ConstantSDNode>(N0.getOperand(0))->isNullValue())
1052 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N1, N0.getOperand(1));
1053 // fold (A + (0-B)) -> A-B
1054 if (N1.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N1.getOperand(0)) &&
1055 cast<ConstantSDNode>(N1.getOperand(0))->isNullValue())
1056 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0, N1.getOperand(1));
1057 // fold (A+(B-A)) -> B
1058 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(1))
1059 return N1.getOperand(0);
1060 // fold ((B-A)+A) -> B
1061 if (N0.getOpcode() == ISD::SUB && N1 == N0.getOperand(1))
1062 return N0.getOperand(0);
1063 // fold (A+(B-(A+C))) to (B-C)
1064 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1065 N0 == N1.getOperand(1).getOperand(0))
1066 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N1.getOperand(0),
1067 N1.getOperand(1).getOperand(1));
1068 // fold (A+(B-(C+A))) to (B-C)
1069 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1070 N0 == N1.getOperand(1).getOperand(1))
1071 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N1.getOperand(0),
1072 N1.getOperand(1).getOperand(0));
1073 // fold (A+((B-A)+or-C)) to (B+or-C)
1074 if ((N1.getOpcode() == ISD::SUB || N1.getOpcode() == ISD::ADD) &&
1075 N1.getOperand(0).getOpcode() == ISD::SUB &&
1076 N0 == N1.getOperand(0).getOperand(1))
1077 return DAG.getNode(N1.getOpcode(), N->getDebugLoc(), VT,
1078 N1.getOperand(0).getOperand(0), N1.getOperand(1));
1080 // fold (A-B)+(C-D) to (A+C)-(B+D) when A or C is constant
1081 if (N0.getOpcode() == ISD::SUB && N1.getOpcode() == ISD::SUB) {
1082 SDValue N00 = N0.getOperand(0);
1083 SDValue N01 = N0.getOperand(1);
1084 SDValue N10 = N1.getOperand(0);
1085 SDValue N11 = N1.getOperand(1);
1087 if (isa<ConstantSDNode>(N00) || isa<ConstantSDNode>(N10))
1088 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1089 DAG.getNode(ISD::ADD, N0.getDebugLoc(), VT, N00, N10),
1090 DAG.getNode(ISD::ADD, N1.getDebugLoc(), VT, N01, N11));
1093 if (!VT.isVector() && SimplifyDemandedBits(SDValue(N, 0)))
1094 return SDValue(N, 0);
1096 // fold (a+b) -> (a|b) iff a and b share no bits.
1097 if (VT.isInteger() && !VT.isVector()) {
1098 APInt LHSZero, LHSOne;
1099 APInt RHSZero, RHSOne;
1100 APInt Mask = APInt::getAllOnesValue(VT.getSizeInBits());
1101 DAG.ComputeMaskedBits(N0, Mask, LHSZero, LHSOne);
1103 if (LHSZero.getBoolValue()) {
1104 DAG.ComputeMaskedBits(N1, Mask, RHSZero, RHSOne);
1106 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1107 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1108 if ((RHSZero & (~LHSZero & Mask)) == (~LHSZero & Mask) ||
1109 (LHSZero & (~RHSZero & Mask)) == (~RHSZero & Mask))
1110 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N1);
1114 // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
1115 if (N0.getOpcode() == ISD::SHL && N0.getNode()->hasOneUse()) {
1116 SDValue Result = combineShlAddConstant(N->getDebugLoc(), N0, N1, DAG);
1117 if (Result.getNode()) return Result;
1119 if (N1.getOpcode() == ISD::SHL && N1.getNode()->hasOneUse()) {
1120 SDValue Result = combineShlAddConstant(N->getDebugLoc(), N1, N0, DAG);
1121 if (Result.getNode()) return Result;
1124 // fold (add (select cc, 0, c), x) -> (select cc, x, (add, x, c))
1125 if (N0.getOpcode() == ISD::SELECT && N0.getNode()->hasOneUse()) {
1126 SDValue Result = combineSelectAndUse(N, N0, N1, DAG, TLI, LegalOperations);
1127 if (Result.getNode()) return Result;
1129 if (N1.getOpcode() == ISD::SELECT && N1.getNode()->hasOneUse()) {
1130 SDValue Result = combineSelectAndUse(N, N1, N0, DAG, TLI, LegalOperations);
1131 if (Result.getNode()) return Result;
1137 SDValue DAGCombiner::visitADDC(SDNode *N) {
1138 SDValue N0 = N->getOperand(0);
1139 SDValue N1 = N->getOperand(1);
1140 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1141 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1142 MVT VT = N0.getValueType();
1144 // If the flag result is dead, turn this into an ADD.
1145 if (N->hasNUsesOfValue(0, 1))
1146 return CombineTo(N, DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N1, N0),
1147 DAG.getNode(ISD::CARRY_FALSE,
1148 N->getDebugLoc(), MVT::Flag));
1150 // canonicalize constant to RHS.
1152 return DAG.getNode(ISD::ADDC, N->getDebugLoc(), N->getVTList(), N1, N0);
1154 // fold (addc x, 0) -> x + no carry out
1155 if (N1C && N1C->isNullValue())
1156 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE,
1157 N->getDebugLoc(), MVT::Flag));
1159 // fold (addc a, b) -> (or a, b), CARRY_FALSE iff a and b share no bits.
1160 APInt LHSZero, LHSOne;
1161 APInt RHSZero, RHSOne;
1162 APInt Mask = APInt::getAllOnesValue(VT.getSizeInBits());
1163 DAG.ComputeMaskedBits(N0, Mask, LHSZero, LHSOne);
1165 if (LHSZero.getBoolValue()) {
1166 DAG.ComputeMaskedBits(N1, Mask, RHSZero, RHSOne);
1168 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1169 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1170 if ((RHSZero & (~LHSZero & Mask)) == (~LHSZero & Mask) ||
1171 (LHSZero & (~RHSZero & Mask)) == (~RHSZero & Mask))
1172 return CombineTo(N, DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N1),
1173 DAG.getNode(ISD::CARRY_FALSE,
1174 N->getDebugLoc(), MVT::Flag));
1180 SDValue DAGCombiner::visitADDE(SDNode *N) {
1181 SDValue N0 = N->getOperand(0);
1182 SDValue N1 = N->getOperand(1);
1183 SDValue CarryIn = N->getOperand(2);
1184 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1185 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1187 // canonicalize constant to RHS
1189 return DAG.getNode(ISD::ADDE, N->getDebugLoc(), N->getVTList(),
1192 // fold (adde x, y, false) -> (addc x, y)
1193 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
1194 return DAG.getNode(ISD::ADDC, N->getDebugLoc(), N->getVTList(), N1, N0);
1199 SDValue DAGCombiner::visitSUB(SDNode *N) {
1200 SDValue N0 = N->getOperand(0);
1201 SDValue N1 = N->getOperand(1);
1202 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1203 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1204 MVT VT = N0.getValueType();
1207 if (VT.isVector()) {
1208 SDValue FoldedVOp = SimplifyVBinOp(N);
1209 if (FoldedVOp.getNode()) return FoldedVOp;
1212 // fold (sub x, x) -> 0
1214 return DAG.getConstant(0, N->getValueType(0));
1215 // fold (sub c1, c2) -> c1-c2
1217 return DAG.FoldConstantArithmetic(ISD::SUB, VT, N0C, N1C);
1218 // fold (sub x, c) -> (add x, -c)
1220 return DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N0,
1221 DAG.getConstant(-N1C->getAPIntValue(), VT));
1222 // fold (A+B)-A -> B
1223 if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1)
1224 return N0.getOperand(1);
1225 // fold (A+B)-B -> A
1226 if (N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1)
1227 return N0.getOperand(0);
1228 // fold ((A+(B+or-C))-B) -> A+or-C
1229 if (N0.getOpcode() == ISD::ADD &&
1230 (N0.getOperand(1).getOpcode() == ISD::SUB ||
1231 N0.getOperand(1).getOpcode() == ISD::ADD) &&
1232 N0.getOperand(1).getOperand(0) == N1)
1233 return DAG.getNode(N0.getOperand(1).getOpcode(), N->getDebugLoc(), VT,
1234 N0.getOperand(0), N0.getOperand(1).getOperand(1));
1235 // fold ((A+(C+B))-B) -> A+C
1236 if (N0.getOpcode() == ISD::ADD &&
1237 N0.getOperand(1).getOpcode() == ISD::ADD &&
1238 N0.getOperand(1).getOperand(1) == N1)
1239 return DAG.getNode(ISD::ADD, N->getDebugLoc(), VT,
1240 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1241 // fold ((A-(B-C))-C) -> A-B
1242 if (N0.getOpcode() == ISD::SUB &&
1243 N0.getOperand(1).getOpcode() == ISD::SUB &&
1244 N0.getOperand(1).getOperand(1) == N1)
1245 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1246 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1247 // fold (sub x, (select cc, 0, c)) -> (select cc, x, (sub, x, c))
1248 if (N1.getOpcode() == ISD::SELECT && N1.getNode()->hasOneUse()) {
1249 SDValue Result = combineSelectAndUse(N, N1, N0, DAG, TLI, LegalOperations);
1250 if (Result.getNode()) return Result;
1253 // If either operand of a sub is undef, the result is undef
1254 if (N0.getOpcode() == ISD::UNDEF)
1256 if (N1.getOpcode() == ISD::UNDEF)
1259 // If the relocation model supports it, consider symbol offsets.
1260 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1261 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA)) {
1262 // fold (sub Sym, c) -> Sym-c
1263 if (N1C && GA->getOpcode() == ISD::GlobalAddress)
1264 return DAG.getGlobalAddress(GA->getGlobal(), VT,
1266 (uint64_t)N1C->getSExtValue());
1267 // fold (sub Sym+c1, Sym+c2) -> c1-c2
1268 if (GlobalAddressSDNode *GB = dyn_cast<GlobalAddressSDNode>(N1))
1269 if (GA->getGlobal() == GB->getGlobal())
1270 return DAG.getConstant((uint64_t)GA->getOffset() - GB->getOffset(),
1277 SDValue DAGCombiner::visitMUL(SDNode *N) {
1278 SDValue N0 = N->getOperand(0);
1279 SDValue N1 = N->getOperand(1);
1280 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1281 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1282 MVT VT = N0.getValueType();
1285 if (VT.isVector()) {
1286 SDValue FoldedVOp = SimplifyVBinOp(N);
1287 if (FoldedVOp.getNode()) return FoldedVOp;
1290 // fold (mul x, undef) -> 0
1291 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
1292 return DAG.getConstant(0, VT);
1293 // fold (mul c1, c2) -> c1*c2
1295 return DAG.FoldConstantArithmetic(ISD::MUL, VT, N0C, N1C);
1296 // canonicalize constant to RHS
1298 return DAG.getNode(ISD::MUL, N->getDebugLoc(), VT, N1, N0);
1299 // fold (mul x, 0) -> 0
1300 if (N1C && N1C->isNullValue())
1302 // fold (mul x, -1) -> 0-x
1303 if (N1C && N1C->isAllOnesValue())
1304 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1305 DAG.getConstant(0, VT), N0);
1306 // fold (mul x, (1 << c)) -> x << c
1307 if (N1C && N1C->getAPIntValue().isPowerOf2())
1308 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0,
1309 DAG.getConstant(N1C->getAPIntValue().logBase2(),
1310 getShiftAmountTy()));
1311 // fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c
1312 if (N1C && (-N1C->getAPIntValue()).isPowerOf2()) {
1313 unsigned Log2Val = (-N1C->getAPIntValue()).logBase2();
1314 // FIXME: If the input is something that is easily negated (e.g. a
1315 // single-use add), we should put the negate there.
1316 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1317 DAG.getConstant(0, VT),
1318 DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0,
1319 DAG.getConstant(Log2Val, getShiftAmountTy())));
1321 // (mul (shl X, c1), c2) -> (mul X, c2 << c1)
1322 if (N1C && N0.getOpcode() == ISD::SHL &&
1323 isa<ConstantSDNode>(N0.getOperand(1))) {
1324 SDValue C3 = DAG.getNode(ISD::SHL, N->getDebugLoc(), VT,
1325 N1, N0.getOperand(1));
1326 AddToWorkList(C3.getNode());
1327 return DAG.getNode(ISD::MUL, N->getDebugLoc(), VT,
1328 N0.getOperand(0), C3);
1331 // Change (mul (shl X, C), Y) -> (shl (mul X, Y), C) when the shift has one
1334 SDValue Sh(0,0), Y(0,0);
1335 // Check for both (mul (shl X, C), Y) and (mul Y, (shl X, C)).
1336 if (N0.getOpcode() == ISD::SHL && isa<ConstantSDNode>(N0.getOperand(1)) &&
1337 N0.getNode()->hasOneUse()) {
1339 } else if (N1.getOpcode() == ISD::SHL &&
1340 isa<ConstantSDNode>(N1.getOperand(1)) &&
1341 N1.getNode()->hasOneUse()) {
1346 SDValue Mul = DAG.getNode(ISD::MUL, N->getDebugLoc(), VT,
1347 Sh.getOperand(0), Y);
1348 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT,
1349 Mul, Sh.getOperand(1));
1353 // fold (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2)
1354 if (N1C && N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse() &&
1355 isa<ConstantSDNode>(N0.getOperand(1)))
1356 return DAG.getNode(ISD::ADD, N->getDebugLoc(), VT,
1357 DAG.getNode(ISD::MUL, N0.getDebugLoc(), VT,
1358 N0.getOperand(0), N1),
1359 DAG.getNode(ISD::MUL, N1.getDebugLoc(), VT,
1360 N0.getOperand(1), N1));
1363 SDValue RMUL = ReassociateOps(ISD::MUL, N->getDebugLoc(), N0, N1);
1364 if (RMUL.getNode() != 0)
1370 SDValue DAGCombiner::visitSDIV(SDNode *N) {
1371 SDValue N0 = N->getOperand(0);
1372 SDValue N1 = N->getOperand(1);
1373 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1374 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1375 MVT VT = N->getValueType(0);
1378 if (VT.isVector()) {
1379 SDValue FoldedVOp = SimplifyVBinOp(N);
1380 if (FoldedVOp.getNode()) return FoldedVOp;
1383 // fold (sdiv c1, c2) -> c1/c2
1384 if (N0C && N1C && !N1C->isNullValue())
1385 return DAG.FoldConstantArithmetic(ISD::SDIV, VT, N0C, N1C);
1386 // fold (sdiv X, 1) -> X
1387 if (N1C && N1C->getSExtValue() == 1LL)
1389 // fold (sdiv X, -1) -> 0-X
1390 if (N1C && N1C->isAllOnesValue())
1391 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1392 DAG.getConstant(0, VT), N0);
1393 // If we know the sign bits of both operands are zero, strength reduce to a
1394 // udiv instead. Handles (X&15) /s 4 -> X&15 >> 2
1395 if (!VT.isVector()) {
1396 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
1397 return DAG.getNode(ISD::UDIV, N->getDebugLoc(), N1.getValueType(),
1400 // fold (sdiv X, pow2) -> simple ops after legalize
1401 if (N1C && !N1C->isNullValue() && !TLI.isIntDivCheap() &&
1402 (isPowerOf2_64(N1C->getSExtValue()) ||
1403 isPowerOf2_64(-N1C->getSExtValue()))) {
1404 // If dividing by powers of two is cheap, then don't perform the following
1406 if (TLI.isPow2DivCheap())
1409 int64_t pow2 = N1C->getSExtValue();
1410 int64_t abs2 = pow2 > 0 ? pow2 : -pow2;
1411 unsigned lg2 = Log2_64(abs2);
1413 // Splat the sign bit into the register
1414 SDValue SGN = DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, N0,
1415 DAG.getConstant(VT.getSizeInBits()-1,
1416 getShiftAmountTy()));
1417 AddToWorkList(SGN.getNode());
1419 // Add (N0 < 0) ? abs2 - 1 : 0;
1420 SDValue SRL = DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, SGN,
1421 DAG.getConstant(VT.getSizeInBits() - lg2,
1422 getShiftAmountTy()));
1423 SDValue ADD = DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N0, SRL);
1424 AddToWorkList(SRL.getNode());
1425 AddToWorkList(ADD.getNode()); // Divide by pow2
1426 SDValue SRA = DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, ADD,
1427 DAG.getConstant(lg2, getShiftAmountTy()));
1429 // If we're dividing by a positive value, we're done. Otherwise, we must
1430 // negate the result.
1434 AddToWorkList(SRA.getNode());
1435 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1436 DAG.getConstant(0, VT), SRA);
1439 // if integer divide is expensive and we satisfy the requirements, emit an
1440 // alternate sequence.
1441 if (N1C && (N1C->getSExtValue() < -1 || N1C->getSExtValue() > 1) &&
1442 !TLI.isIntDivCheap()) {
1443 SDValue Op = BuildSDIV(N);
1444 if (Op.getNode()) return Op;
1448 if (N0.getOpcode() == ISD::UNDEF)
1449 return DAG.getConstant(0, VT);
1450 // X / undef -> undef
1451 if (N1.getOpcode() == ISD::UNDEF)
1457 SDValue DAGCombiner::visitUDIV(SDNode *N) {
1458 SDValue N0 = N->getOperand(0);
1459 SDValue N1 = N->getOperand(1);
1460 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1461 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1462 MVT VT = N->getValueType(0);
1465 if (VT.isVector()) {
1466 SDValue FoldedVOp = SimplifyVBinOp(N);
1467 if (FoldedVOp.getNode()) return FoldedVOp;
1470 // fold (udiv c1, c2) -> c1/c2
1471 if (N0C && N1C && !N1C->isNullValue())
1472 return DAG.FoldConstantArithmetic(ISD::UDIV, VT, N0C, N1C);
1473 // fold (udiv x, (1 << c)) -> x >>u c
1474 if (N1C && N1C->getAPIntValue().isPowerOf2())
1475 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0,
1476 DAG.getConstant(N1C->getAPIntValue().logBase2(),
1477 getShiftAmountTy()));
1478 // fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) iff c is power of 2
1479 if (N1.getOpcode() == ISD::SHL) {
1480 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
1481 if (SHC->getAPIntValue().isPowerOf2()) {
1482 MVT ADDVT = N1.getOperand(1).getValueType();
1483 SDValue Add = DAG.getNode(ISD::ADD, N->getDebugLoc(), ADDVT,
1485 DAG.getConstant(SHC->getAPIntValue()
1488 AddToWorkList(Add.getNode());
1489 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0, Add);
1493 // fold (udiv x, c) -> alternate
1494 if (N1C && !N1C->isNullValue() && !TLI.isIntDivCheap()) {
1495 SDValue Op = BuildUDIV(N);
1496 if (Op.getNode()) return Op;
1500 if (N0.getOpcode() == ISD::UNDEF)
1501 return DAG.getConstant(0, VT);
1502 // X / undef -> undef
1503 if (N1.getOpcode() == ISD::UNDEF)
1509 SDValue DAGCombiner::visitSREM(SDNode *N) {
1510 SDValue N0 = N->getOperand(0);
1511 SDValue N1 = N->getOperand(1);
1512 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1513 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1514 MVT VT = N->getValueType(0);
1516 // fold (srem c1, c2) -> c1%c2
1517 if (N0C && N1C && !N1C->isNullValue())
1518 return DAG.FoldConstantArithmetic(ISD::SREM, VT, N0C, N1C);
1519 // If we know the sign bits of both operands are zero, strength reduce to a
1520 // urem instead. Handles (X & 0x0FFFFFFF) %s 16 -> X&15
1521 if (!VT.isVector()) {
1522 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
1523 return DAG.getNode(ISD::UREM, N->getDebugLoc(), VT, N0, N1);
1526 // If X/C can be simplified by the division-by-constant logic, lower
1527 // X%C to the equivalent of X-X/C*C.
1528 if (N1C && !N1C->isNullValue()) {
1529 SDValue Div = DAG.getNode(ISD::SDIV, N->getDebugLoc(), VT, N0, N1);
1530 AddToWorkList(Div.getNode());
1531 SDValue OptimizedDiv = combine(Div.getNode());
1532 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
1533 SDValue Mul = DAG.getNode(ISD::MUL, N->getDebugLoc(), VT,
1535 SDValue Sub = DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0, Mul);
1536 AddToWorkList(Mul.getNode());
1542 if (N0.getOpcode() == ISD::UNDEF)
1543 return DAG.getConstant(0, VT);
1544 // X % undef -> undef
1545 if (N1.getOpcode() == ISD::UNDEF)
1551 SDValue DAGCombiner::visitUREM(SDNode *N) {
1552 SDValue N0 = N->getOperand(0);
1553 SDValue N1 = N->getOperand(1);
1554 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1555 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1556 MVT VT = N->getValueType(0);
1558 // fold (urem c1, c2) -> c1%c2
1559 if (N0C && N1C && !N1C->isNullValue())
1560 return DAG.FoldConstantArithmetic(ISD::UREM, VT, N0C, N1C);
1561 // fold (urem x, pow2) -> (and x, pow2-1)
1562 if (N1C && !N1C->isNullValue() && N1C->getAPIntValue().isPowerOf2())
1563 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0,
1564 DAG.getConstant(N1C->getAPIntValue()-1,VT));
1565 // fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1))
1566 if (N1.getOpcode() == ISD::SHL) {
1567 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
1568 if (SHC->getAPIntValue().isPowerOf2()) {
1570 DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N1,
1571 DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()),
1573 AddToWorkList(Add.getNode());
1574 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0, Add);
1579 // If X/C can be simplified by the division-by-constant logic, lower
1580 // X%C to the equivalent of X-X/C*C.
1581 if (N1C && !N1C->isNullValue()) {
1582 SDValue Div = DAG.getNode(ISD::UDIV, N->getDebugLoc(), VT, N0, N1);
1583 AddToWorkList(Div.getNode());
1584 SDValue OptimizedDiv = combine(Div.getNode());
1585 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
1586 SDValue Mul = DAG.getNode(ISD::MUL, N->getDebugLoc(), VT,
1588 SDValue Sub = DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0, Mul);
1589 AddToWorkList(Mul.getNode());
1595 if (N0.getOpcode() == ISD::UNDEF)
1596 return DAG.getConstant(0, VT);
1597 // X % undef -> undef
1598 if (N1.getOpcode() == ISD::UNDEF)
1604 SDValue DAGCombiner::visitMULHS(SDNode *N) {
1605 SDValue N0 = N->getOperand(0);
1606 SDValue N1 = N->getOperand(1);
1607 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1608 MVT VT = N->getValueType(0);
1610 // fold (mulhs x, 0) -> 0
1611 if (N1C && N1C->isNullValue())
1613 // fold (mulhs x, 1) -> (sra x, size(x)-1)
1614 if (N1C && N1C->getAPIntValue() == 1)
1615 return DAG.getNode(ISD::SRA, N->getDebugLoc(), N0.getValueType(), N0,
1616 DAG.getConstant(N0.getValueType().getSizeInBits() - 1,
1617 getShiftAmountTy()));
1618 // fold (mulhs x, undef) -> 0
1619 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
1620 return DAG.getConstant(0, VT);
1625 SDValue DAGCombiner::visitMULHU(SDNode *N) {
1626 SDValue N0 = N->getOperand(0);
1627 SDValue N1 = N->getOperand(1);
1628 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1629 MVT VT = N->getValueType(0);
1631 // fold (mulhu x, 0) -> 0
1632 if (N1C && N1C->isNullValue())
1634 // fold (mulhu x, 1) -> 0
1635 if (N1C && N1C->getAPIntValue() == 1)
1636 return DAG.getConstant(0, N0.getValueType());
1637 // fold (mulhu x, undef) -> 0
1638 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
1639 return DAG.getConstant(0, VT);
1644 /// SimplifyNodeWithTwoResults - Perform optimizations common to nodes that
1645 /// compute two values. LoOp and HiOp give the opcodes for the two computations
1646 /// that are being performed. Return true if a simplification was made.
1648 SDValue DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
1650 // If the high half is not needed, just compute the low half.
1651 bool HiExists = N->hasAnyUseOfValue(1);
1653 (!LegalOperations ||
1654 TLI.isOperationLegal(LoOp, N->getValueType(0)))) {
1655 SDValue Res = DAG.getNode(LoOp, N->getDebugLoc(), N->getValueType(0),
1656 N->op_begin(), N->getNumOperands());
1657 return CombineTo(N, Res, Res);
1660 // If the low half is not needed, just compute the high half.
1661 bool LoExists = N->hasAnyUseOfValue(0);
1663 (!LegalOperations ||
1664 TLI.isOperationLegal(HiOp, N->getValueType(1)))) {
1665 SDValue Res = DAG.getNode(HiOp, N->getDebugLoc(), N->getValueType(1),
1666 N->op_begin(), N->getNumOperands());
1667 return CombineTo(N, Res, Res);
1670 // If both halves are used, return as it is.
1671 if (LoExists && HiExists)
1674 // If the two computed results can be simplified separately, separate them.
1676 SDValue Lo = DAG.getNode(LoOp, N->getDebugLoc(), N->getValueType(0),
1677 N->op_begin(), N->getNumOperands());
1678 AddToWorkList(Lo.getNode());
1679 SDValue LoOpt = combine(Lo.getNode());
1680 if (LoOpt.getNode() && LoOpt.getNode() != Lo.getNode() &&
1681 (!LegalOperations ||
1682 TLI.isOperationLegal(LoOpt.getOpcode(), LoOpt.getValueType())))
1683 return CombineTo(N, LoOpt, LoOpt);
1687 SDValue Hi = DAG.getNode(HiOp, N->getDebugLoc(), N->getValueType(1),
1688 N->op_begin(), N->getNumOperands());
1689 AddToWorkList(Hi.getNode());
1690 SDValue HiOpt = combine(Hi.getNode());
1691 if (HiOpt.getNode() && HiOpt != Hi &&
1692 (!LegalOperations ||
1693 TLI.isOperationLegal(HiOpt.getOpcode(), HiOpt.getValueType())))
1694 return CombineTo(N, HiOpt, HiOpt);
1700 SDValue DAGCombiner::visitSMUL_LOHI(SDNode *N) {
1701 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHS);
1702 if (Res.getNode()) return Res;
1707 SDValue DAGCombiner::visitUMUL_LOHI(SDNode *N) {
1708 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHU);
1709 if (Res.getNode()) return Res;
1714 SDValue DAGCombiner::visitSDIVREM(SDNode *N) {
1715 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::SDIV, ISD::SREM);
1716 if (Res.getNode()) return Res;
1721 SDValue DAGCombiner::visitUDIVREM(SDNode *N) {
1722 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::UDIV, ISD::UREM);
1723 if (Res.getNode()) return Res;
1728 /// SimplifyBinOpWithSameOpcodeHands - If this is a binary operator with
1729 /// two operands of the same opcode, try to simplify it.
1730 SDValue DAGCombiner::SimplifyBinOpWithSameOpcodeHands(SDNode *N) {
1731 SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
1732 MVT VT = N0.getValueType();
1733 assert(N0.getOpcode() == N1.getOpcode() && "Bad input!");
1735 // For each of OP in AND/OR/XOR:
1736 // fold (OP (zext x), (zext y)) -> (zext (OP x, y))
1737 // fold (OP (sext x), (sext y)) -> (sext (OP x, y))
1738 // fold (OP (aext x), (aext y)) -> (aext (OP x, y))
1739 // fold (OP (trunc x), (trunc y)) -> (trunc (OP x, y))
1740 if ((N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND||
1741 N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::TRUNCATE) &&
1742 N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType()) {
1743 SDValue ORNode = DAG.getNode(N->getOpcode(), N0.getDebugLoc(),
1744 N0.getOperand(0).getValueType(),
1745 N0.getOperand(0), N1.getOperand(0));
1746 AddToWorkList(ORNode.getNode());
1747 return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT, ORNode);
1750 // For each of OP in SHL/SRL/SRA/AND...
1751 // fold (and (OP x, z), (OP y, z)) -> (OP (and x, y), z)
1752 // fold (or (OP x, z), (OP y, z)) -> (OP (or x, y), z)
1753 // fold (xor (OP x, z), (OP y, z)) -> (OP (xor x, y), z)
1754 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL ||
1755 N0.getOpcode() == ISD::SRA || N0.getOpcode() == ISD::AND) &&
1756 N0.getOperand(1) == N1.getOperand(1)) {
1757 SDValue ORNode = DAG.getNode(N->getOpcode(), N0.getDebugLoc(),
1758 N0.getOperand(0).getValueType(),
1759 N0.getOperand(0), N1.getOperand(0));
1760 AddToWorkList(ORNode.getNode());
1761 return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT,
1762 ORNode, N0.getOperand(1));
1768 SDValue DAGCombiner::visitAND(SDNode *N) {
1769 SDValue N0 = N->getOperand(0);
1770 SDValue N1 = N->getOperand(1);
1771 SDValue LL, LR, RL, RR, CC0, CC1;
1772 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1773 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1774 MVT VT = N1.getValueType();
1775 unsigned BitWidth = VT.getSizeInBits();
1778 if (VT.isVector()) {
1779 SDValue FoldedVOp = SimplifyVBinOp(N);
1780 if (FoldedVOp.getNode()) return FoldedVOp;
1783 // fold (and x, undef) -> 0
1784 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
1785 return DAG.getConstant(0, VT);
1786 // fold (and c1, c2) -> c1&c2
1788 return DAG.FoldConstantArithmetic(ISD::AND, VT, N0C, N1C);
1789 // canonicalize constant to RHS
1791 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N1, N0);
1792 // fold (and x, -1) -> x
1793 if (N1C && N1C->isAllOnesValue())
1795 // if (and x, c) is known to be zero, return 0
1796 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
1797 APInt::getAllOnesValue(BitWidth)))
1798 return DAG.getConstant(0, VT);
1800 SDValue RAND = ReassociateOps(ISD::AND, N->getDebugLoc(), N0, N1);
1801 if (RAND.getNode() != 0)
1803 // fold (and (or x, 0xFFFF), 0xFF) -> 0xFF
1804 if (N1C && N0.getOpcode() == ISD::OR)
1805 if (ConstantSDNode *ORI = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
1806 if ((ORI->getAPIntValue() & N1C->getAPIntValue()) == N1C->getAPIntValue())
1808 // fold (and (any_ext V), c) -> (zero_ext V) if 'and' only clears top bits.
1809 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
1810 SDValue N0Op0 = N0.getOperand(0);
1811 APInt Mask = ~N1C->getAPIntValue();
1812 Mask.trunc(N0Op0.getValueSizeInBits());
1813 if (DAG.MaskedValueIsZero(N0Op0, Mask)) {
1814 SDValue Zext = DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(),
1815 N0.getValueType(), N0Op0);
1817 // Replace uses of the AND with uses of the Zero extend node.
1820 // We actually want to replace all uses of the any_extend with the
1821 // zero_extend, to avoid duplicating things. This will later cause this
1822 // AND to be folded.
1823 CombineTo(N0.getNode(), Zext);
1824 return SDValue(N, 0); // Return N so it doesn't get rechecked!
1827 // fold (and (setcc x), (setcc y)) -> (setcc (and x, y))
1828 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
1829 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
1830 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
1832 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
1833 LL.getValueType().isInteger()) {
1834 // fold (and (seteq X, 0), (seteq Y, 0)) -> (seteq (or X, Y), 0)
1835 if (cast<ConstantSDNode>(LR)->isNullValue() && Op1 == ISD::SETEQ) {
1836 SDValue ORNode = DAG.getNode(ISD::OR, N0.getDebugLoc(),
1837 LR.getValueType(), LL, RL);
1838 AddToWorkList(ORNode.getNode());
1839 return DAG.getSetCC(N->getDebugLoc(), VT, ORNode, LR, Op1);
1841 // fold (and (seteq X, -1), (seteq Y, -1)) -> (seteq (and X, Y), -1)
1842 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETEQ) {
1843 SDValue ANDNode = DAG.getNode(ISD::AND, N0.getDebugLoc(),
1844 LR.getValueType(), LL, RL);
1845 AddToWorkList(ANDNode.getNode());
1846 return DAG.getSetCC(N->getDebugLoc(), VT, ANDNode, LR, Op1);
1848 // fold (and (setgt X, -1), (setgt Y, -1)) -> (setgt (or X, Y), -1)
1849 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETGT) {
1850 SDValue ORNode = DAG.getNode(ISD::OR, N0.getDebugLoc(),
1851 LR.getValueType(), LL, RL);
1852 AddToWorkList(ORNode.getNode());
1853 return DAG.getSetCC(N->getDebugLoc(), VT, ORNode, LR, Op1);
1856 // canonicalize equivalent to ll == rl
1857 if (LL == RR && LR == RL) {
1858 Op1 = ISD::getSetCCSwappedOperands(Op1);
1861 if (LL == RL && LR == RR) {
1862 bool isInteger = LL.getValueType().isInteger();
1863 ISD::CondCode Result = ISD::getSetCCAndOperation(Op0, Op1, isInteger);
1864 if (Result != ISD::SETCC_INVALID &&
1865 (!LegalOperations || TLI.isCondCodeLegal(Result, LL.getValueType())))
1866 return DAG.getSetCC(N->getDebugLoc(), N0.getValueType(),
1871 // Simplify: (and (op x...), (op y...)) -> (op (and x, y))
1872 if (N0.getOpcode() == N1.getOpcode()) {
1873 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
1874 if (Tmp.getNode()) return Tmp;
1877 // fold (and (sign_extend_inreg x, i16 to i32), 1) -> (and x, 1)
1878 // fold (and (sra)) -> (and (srl)) when possible.
1879 if (!VT.isVector() &&
1880 SimplifyDemandedBits(SDValue(N, 0)))
1881 return SDValue(N, 0);
1882 // fold (zext_inreg (extload x)) -> (zextload x)
1883 if (ISD::isEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode())) {
1884 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
1885 MVT EVT = LN0->getMemoryVT();
1886 // If we zero all the possible extended bits, then we can turn this into
1887 // a zextload if we are running before legalize or the operation is legal.
1888 unsigned BitWidth = N1.getValueSizeInBits();
1889 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
1890 BitWidth - EVT.getSizeInBits())) &&
1891 ((!LegalOperations && !LN0->isVolatile()) ||
1892 TLI.isLoadExtLegal(ISD::ZEXTLOAD, EVT))) {
1893 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, N0.getDebugLoc(), VT,
1894 LN0->getChain(), LN0->getBasePtr(),
1896 LN0->getSrcValueOffset(), EVT,
1897 LN0->isVolatile(), LN0->getAlignment());
1899 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
1900 return SDValue(N, 0); // Return N so it doesn't get rechecked!
1903 // fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use
1904 if (ISD::isSEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
1906 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
1907 MVT EVT = LN0->getMemoryVT();
1908 // If we zero all the possible extended bits, then we can turn this into
1909 // a zextload if we are running before legalize or the operation is legal.
1910 unsigned BitWidth = N1.getValueSizeInBits();
1911 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
1912 BitWidth - EVT.getSizeInBits())) &&
1913 ((!LegalOperations && !LN0->isVolatile()) ||
1914 TLI.isLoadExtLegal(ISD::ZEXTLOAD, EVT))) {
1915 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, N0.getDebugLoc(), VT,
1917 LN0->getBasePtr(), LN0->getSrcValue(),
1918 LN0->getSrcValueOffset(), EVT,
1919 LN0->isVolatile(), LN0->getAlignment());
1921 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
1922 return SDValue(N, 0); // Return N so it doesn't get rechecked!
1926 // fold (and (load x), 255) -> (zextload x, i8)
1927 // fold (and (extload x, i16), 255) -> (zextload x, i8)
1928 if (N1C && N0.getOpcode() == ISD::LOAD) {
1929 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
1930 if (LN0->getExtensionType() != ISD::SEXTLOAD &&
1931 LN0->isUnindexed() && N0.hasOneUse() &&
1932 // Do not change the width of a volatile load.
1933 !LN0->isVolatile()) {
1934 MVT EVT = MVT::Other;
1935 uint32_t ActiveBits = N1C->getAPIntValue().getActiveBits();
1936 if (ActiveBits > 0 && APIntOps::isMask(ActiveBits, N1C->getAPIntValue()))
1937 EVT = MVT::getIntegerVT(ActiveBits);
1939 MVT LoadedVT = LN0->getMemoryVT();
1941 // Do not generate loads of non-round integer types since these can
1942 // be expensive (and would be wrong if the type is not byte sized).
1943 if (EVT != MVT::Other && LoadedVT.bitsGT(EVT) && EVT.isRound() &&
1944 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, EVT))) {
1945 MVT PtrType = N0.getOperand(1).getValueType();
1947 // For big endian targets, we need to add an offset to the pointer to
1948 // load the correct bytes. For little endian systems, we merely need to
1949 // read fewer bytes from the same pointer.
1950 unsigned LVTStoreBytes = LoadedVT.getStoreSizeInBits()/8;
1951 unsigned EVTStoreBytes = EVT.getStoreSizeInBits()/8;
1952 unsigned PtrOff = LVTStoreBytes - EVTStoreBytes;
1953 unsigned Alignment = LN0->getAlignment();
1954 SDValue NewPtr = LN0->getBasePtr();
1956 if (TLI.isBigEndian()) {
1957 NewPtr = DAG.getNode(ISD::ADD, LN0->getDebugLoc(), PtrType,
1958 NewPtr, DAG.getConstant(PtrOff, PtrType));
1959 Alignment = MinAlign(Alignment, PtrOff);
1962 AddToWorkList(NewPtr.getNode());
1964 DAG.getExtLoad(ISD::ZEXTLOAD, LN0->getDebugLoc(), VT, LN0->getChain(),
1965 NewPtr, LN0->getSrcValue(), LN0->getSrcValueOffset(),
1966 EVT, LN0->isVolatile(), Alignment);
1968 CombineTo(N0.getNode(), Load, Load.getValue(1));
1969 return SDValue(N, 0); // Return N so it doesn't get rechecked!
1977 SDValue DAGCombiner::visitOR(SDNode *N) {
1978 SDValue N0 = N->getOperand(0);
1979 SDValue N1 = N->getOperand(1);
1980 SDValue LL, LR, RL, RR, CC0, CC1;
1981 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1982 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1983 MVT VT = N1.getValueType();
1986 if (VT.isVector()) {
1987 SDValue FoldedVOp = SimplifyVBinOp(N);
1988 if (FoldedVOp.getNode()) return FoldedVOp;
1991 // fold (or x, undef) -> -1
1992 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
1993 return DAG.getConstant(~0ULL, VT);
1994 // fold (or c1, c2) -> c1|c2
1996 return DAG.FoldConstantArithmetic(ISD::OR, VT, N0C, N1C);
1997 // canonicalize constant to RHS
1999 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N1, N0);
2000 // fold (or x, 0) -> x
2001 if (N1C && N1C->isNullValue())
2003 // fold (or x, -1) -> -1
2004 if (N1C && N1C->isAllOnesValue())
2006 // fold (or x, c) -> c iff (x & ~c) == 0
2007 if (N1C && DAG.MaskedValueIsZero(N0, ~N1C->getAPIntValue()))
2010 SDValue ROR = ReassociateOps(ISD::OR, N->getDebugLoc(), N0, N1);
2011 if (ROR.getNode() != 0)
2013 // Canonicalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2)
2014 if (N1C && N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
2015 isa<ConstantSDNode>(N0.getOperand(1))) {
2016 ConstantSDNode *C1 = cast<ConstantSDNode>(N0.getOperand(1));
2017 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
2018 DAG.getNode(ISD::OR, N0.getDebugLoc(), VT,
2019 N0.getOperand(0), N1),
2020 DAG.FoldConstantArithmetic(ISD::OR, VT, N1C, C1));
2022 // fold (or (setcc x), (setcc y)) -> (setcc (or x, y))
2023 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
2024 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
2025 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
2027 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
2028 LL.getValueType().isInteger()) {
2029 // fold (or (setne X, 0), (setne Y, 0)) -> (setne (or X, Y), 0)
2030 // fold (or (setlt X, 0), (setlt Y, 0)) -> (setne (or X, Y), 0)
2031 if (cast<ConstantSDNode>(LR)->isNullValue() &&
2032 (Op1 == ISD::SETNE || Op1 == ISD::SETLT)) {
2033 SDValue ORNode = DAG.getNode(ISD::OR, LR.getDebugLoc(),
2034 LR.getValueType(), LL, RL);
2035 AddToWorkList(ORNode.getNode());
2036 return DAG.getSetCC(N->getDebugLoc(), VT, ORNode, LR, Op1);
2038 // fold (or (setne X, -1), (setne Y, -1)) -> (setne (and X, Y), -1)
2039 // fold (or (setgt X, -1), (setgt Y -1)) -> (setgt (and X, Y), -1)
2040 if (cast<ConstantSDNode>(LR)->isAllOnesValue() &&
2041 (Op1 == ISD::SETNE || Op1 == ISD::SETGT)) {
2042 SDValue ANDNode = DAG.getNode(ISD::AND, LR.getDebugLoc(),
2043 LR.getValueType(), LL, RL);
2044 AddToWorkList(ANDNode.getNode());
2045 return DAG.getSetCC(N->getDebugLoc(), VT, ANDNode, LR, Op1);
2048 // canonicalize equivalent to ll == rl
2049 if (LL == RR && LR == RL) {
2050 Op1 = ISD::getSetCCSwappedOperands(Op1);
2053 if (LL == RL && LR == RR) {
2054 bool isInteger = LL.getValueType().isInteger();
2055 ISD::CondCode Result = ISD::getSetCCOrOperation(Op0, Op1, isInteger);
2056 if (Result != ISD::SETCC_INVALID &&
2057 (!LegalOperations || TLI.isCondCodeLegal(Result, LL.getValueType())))
2058 return DAG.getSetCC(N->getDebugLoc(), N0.getValueType(),
2063 // Simplify: (or (op x...), (op y...)) -> (op (or x, y))
2064 if (N0.getOpcode() == N1.getOpcode()) {
2065 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
2066 if (Tmp.getNode()) return Tmp;
2069 // (or (and X, C1), (and Y, C2)) -> (and (or X, Y), C3) if possible.
2070 if (N0.getOpcode() == ISD::AND &&
2071 N1.getOpcode() == ISD::AND &&
2072 N0.getOperand(1).getOpcode() == ISD::Constant &&
2073 N1.getOperand(1).getOpcode() == ISD::Constant &&
2074 // Don't increase # computations.
2075 (N0.getNode()->hasOneUse() || N1.getNode()->hasOneUse())) {
2076 // We can only do this xform if we know that bits from X that are set in C2
2077 // but not in C1 are already zero. Likewise for Y.
2078 const APInt &LHSMask =
2079 cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
2080 const APInt &RHSMask =
2081 cast<ConstantSDNode>(N1.getOperand(1))->getAPIntValue();
2083 if (DAG.MaskedValueIsZero(N0.getOperand(0), RHSMask&~LHSMask) &&
2084 DAG.MaskedValueIsZero(N1.getOperand(0), LHSMask&~RHSMask)) {
2085 SDValue X = DAG.getNode(ISD::OR, N0.getDebugLoc(), VT,
2086 N0.getOperand(0), N1.getOperand(0));
2087 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, X,
2088 DAG.getConstant(LHSMask | RHSMask, VT));
2092 // See if this is some rotate idiom.
2093 if (SDNode *Rot = MatchRotate(N0, N1, N->getDebugLoc()))
2094 return SDValue(Rot, 0);
2099 /// MatchRotateHalf - Match "(X shl/srl V1) & V2" where V2 may not be present.
2100 static bool MatchRotateHalf(SDValue Op, SDValue &Shift, SDValue &Mask) {
2101 if (Op.getOpcode() == ISD::AND) {
2102 if (isa<ConstantSDNode>(Op.getOperand(1))) {
2103 Mask = Op.getOperand(1);
2104 Op = Op.getOperand(0);
2110 if (Op.getOpcode() == ISD::SRL || Op.getOpcode() == ISD::SHL) {
2118 // MatchRotate - Handle an 'or' of two operands. If this is one of the many
2119 // idioms for rotate, and if the target supports rotation instructions, generate
2121 SDNode *DAGCombiner::MatchRotate(SDValue LHS, SDValue RHS, DebugLoc DL) {
2122 // Must be a legal type. Expanded 'n promoted things won't work with rotates.
2123 MVT VT = LHS.getValueType();
2124 if (!TLI.isTypeLegal(VT)) return 0;
2126 // The target must have at least one rotate flavor.
2127 bool HasROTL = TLI.isOperationLegalOrCustom(ISD::ROTL, VT);
2128 bool HasROTR = TLI.isOperationLegalOrCustom(ISD::ROTR, VT);
2129 if (!HasROTL && !HasROTR) return 0;
2131 // Match "(X shl/srl V1) & V2" where V2 may not be present.
2132 SDValue LHSShift; // The shift.
2133 SDValue LHSMask; // AND value if any.
2134 if (!MatchRotateHalf(LHS, LHSShift, LHSMask))
2135 return 0; // Not part of a rotate.
2137 SDValue RHSShift; // The shift.
2138 SDValue RHSMask; // AND value if any.
2139 if (!MatchRotateHalf(RHS, RHSShift, RHSMask))
2140 return 0; // Not part of a rotate.
2142 if (LHSShift.getOperand(0) != RHSShift.getOperand(0))
2143 return 0; // Not shifting the same value.
2145 if (LHSShift.getOpcode() == RHSShift.getOpcode())
2146 return 0; // Shifts must disagree.
2148 // Canonicalize shl to left side in a shl/srl pair.
2149 if (RHSShift.getOpcode() == ISD::SHL) {
2150 std::swap(LHS, RHS);
2151 std::swap(LHSShift, RHSShift);
2152 std::swap(LHSMask , RHSMask );
2155 unsigned OpSizeInBits = VT.getSizeInBits();
2156 SDValue LHSShiftArg = LHSShift.getOperand(0);
2157 SDValue LHSShiftAmt = LHSShift.getOperand(1);
2158 SDValue RHSShiftAmt = RHSShift.getOperand(1);
2160 // fold (or (shl x, C1), (srl x, C2)) -> (rotl x, C1)
2161 // fold (or (shl x, C1), (srl x, C2)) -> (rotr x, C2)
2162 if (LHSShiftAmt.getOpcode() == ISD::Constant &&
2163 RHSShiftAmt.getOpcode() == ISD::Constant) {
2164 uint64_t LShVal = cast<ConstantSDNode>(LHSShiftAmt)->getZExtValue();
2165 uint64_t RShVal = cast<ConstantSDNode>(RHSShiftAmt)->getZExtValue();
2166 if ((LShVal + RShVal) != OpSizeInBits)
2171 Rot = DAG.getNode(ISD::ROTL, DL, VT, LHSShiftArg, LHSShiftAmt);
2173 Rot = DAG.getNode(ISD::ROTR, DL, VT, LHSShiftArg, RHSShiftAmt);
2175 // If there is an AND of either shifted operand, apply it to the result.
2176 if (LHSMask.getNode() || RHSMask.getNode()) {
2177 APInt Mask = APInt::getAllOnesValue(OpSizeInBits);
2179 if (LHSMask.getNode()) {
2180 APInt RHSBits = APInt::getLowBitsSet(OpSizeInBits, LShVal);
2181 Mask &= cast<ConstantSDNode>(LHSMask)->getAPIntValue() | RHSBits;
2183 if (RHSMask.getNode()) {
2184 APInt LHSBits = APInt::getHighBitsSet(OpSizeInBits, RShVal);
2185 Mask &= cast<ConstantSDNode>(RHSMask)->getAPIntValue() | LHSBits;
2188 Rot = DAG.getNode(ISD::AND, DL, VT, Rot, DAG.getConstant(Mask, VT));
2191 return Rot.getNode();
2194 // If there is a mask here, and we have a variable shift, we can't be sure
2195 // that we're masking out the right stuff.
2196 if (LHSMask.getNode() || RHSMask.getNode())
2199 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotl x, y)
2200 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotr x, (sub 32, y))
2201 if (RHSShiftAmt.getOpcode() == ISD::SUB &&
2202 LHSShiftAmt == RHSShiftAmt.getOperand(1)) {
2203 if (ConstantSDNode *SUBC =
2204 dyn_cast<ConstantSDNode>(RHSShiftAmt.getOperand(0))) {
2205 if (SUBC->getAPIntValue() == OpSizeInBits) {
2207 return DAG.getNode(ISD::ROTL, DL, VT,
2208 LHSShiftArg, LHSShiftAmt).getNode();
2210 return DAG.getNode(ISD::ROTR, DL, VT,
2211 LHSShiftArg, RHSShiftAmt).getNode();
2216 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotr x, y)
2217 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotl x, (sub 32, y))
2218 if (LHSShiftAmt.getOpcode() == ISD::SUB &&
2219 RHSShiftAmt == LHSShiftAmt.getOperand(1)) {
2220 if (ConstantSDNode *SUBC =
2221 dyn_cast<ConstantSDNode>(LHSShiftAmt.getOperand(0))) {
2222 if (SUBC->getAPIntValue() == OpSizeInBits) {
2224 return DAG.getNode(ISD::ROTR, DL, VT,
2225 LHSShiftArg, RHSShiftAmt).getNode();
2227 return DAG.getNode(ISD::ROTL, DL, VT,
2228 LHSShiftArg, LHSShiftAmt).getNode();
2233 // Look for sign/zext/any-extended or truncate cases:
2234 if ((LHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND
2235 || LHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND
2236 || LHSShiftAmt.getOpcode() == ISD::ANY_EXTEND
2237 || LHSShiftAmt.getOpcode() == ISD::TRUNCATE) &&
2238 (RHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND
2239 || RHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND
2240 || RHSShiftAmt.getOpcode() == ISD::ANY_EXTEND
2241 || RHSShiftAmt.getOpcode() == ISD::TRUNCATE)) {
2242 SDValue LExtOp0 = LHSShiftAmt.getOperand(0);
2243 SDValue RExtOp0 = RHSShiftAmt.getOperand(0);
2244 if (RExtOp0.getOpcode() == ISD::SUB &&
2245 RExtOp0.getOperand(1) == LExtOp0) {
2246 // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
2248 // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
2249 // (rotr x, (sub 32, y))
2250 if (ConstantSDNode *SUBC =
2251 dyn_cast<ConstantSDNode>(RExtOp0.getOperand(0))) {
2252 if (SUBC->getAPIntValue() == OpSizeInBits) {
2253 return DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT,
2255 HasROTL ? LHSShiftAmt : RHSShiftAmt).getNode();
2258 } else if (LExtOp0.getOpcode() == ISD::SUB &&
2259 RExtOp0 == LExtOp0.getOperand(1)) {
2260 // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext y))) ->
2262 // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext y))) ->
2263 // (rotl x, (sub 32, y))
2264 if (ConstantSDNode *SUBC =
2265 dyn_cast<ConstantSDNode>(LExtOp0.getOperand(0))) {
2266 if (SUBC->getAPIntValue() == OpSizeInBits) {
2267 return DAG.getNode(HasROTR ? ISD::ROTR : ISD::ROTL, DL, VT,
2269 HasROTR ? RHSShiftAmt : LHSShiftAmt).getNode();
2278 SDValue DAGCombiner::visitXOR(SDNode *N) {
2279 SDValue N0 = N->getOperand(0);
2280 SDValue N1 = N->getOperand(1);
2281 SDValue LHS, RHS, CC;
2282 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2283 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2284 MVT VT = N0.getValueType();
2287 if (VT.isVector()) {
2288 SDValue FoldedVOp = SimplifyVBinOp(N);
2289 if (FoldedVOp.getNode()) return FoldedVOp;
2292 // fold (xor undef, undef) -> 0. This is a common idiom (misuse).
2293 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
2294 return DAG.getConstant(0, VT);
2295 // fold (xor x, undef) -> undef
2296 if (N0.getOpcode() == ISD::UNDEF)
2298 if (N1.getOpcode() == ISD::UNDEF)
2300 // fold (xor c1, c2) -> c1^c2
2302 return DAG.FoldConstantArithmetic(ISD::XOR, VT, N0C, N1C);
2303 // canonicalize constant to RHS
2305 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N1, N0);
2306 // fold (xor x, 0) -> x
2307 if (N1C && N1C->isNullValue())
2310 SDValue RXOR = ReassociateOps(ISD::XOR, N->getDebugLoc(), N0, N1);
2311 if (RXOR.getNode() != 0)
2314 // fold !(x cc y) -> (x !cc y)
2315 if (N1C && N1C->getAPIntValue() == 1 && isSetCCEquivalent(N0, LHS, RHS, CC)) {
2316 bool isInt = LHS.getValueType().isInteger();
2317 ISD::CondCode NotCC = ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
2320 if (!LegalOperations || TLI.isCondCodeLegal(NotCC, LHS.getValueType())) {
2321 switch (N0.getOpcode()) {
2323 assert(0 && "Unhandled SetCC Equivalent!");
2326 return DAG.getSetCC(N->getDebugLoc(), VT, LHS, RHS, NotCC);
2327 case ISD::SELECT_CC:
2328 return DAG.getSelectCC(N->getDebugLoc(), LHS, RHS, N0.getOperand(2),
2329 N0.getOperand(3), NotCC);
2334 // fold (not (zext (setcc x, y))) -> (zext (not (setcc x, y)))
2335 if (N1C && N1C->getAPIntValue() == 1 && N0.getOpcode() == ISD::ZERO_EXTEND &&
2336 N0.getNode()->hasOneUse() &&
2337 isSetCCEquivalent(N0.getOperand(0), LHS, RHS, CC)){
2338 SDValue V = N0.getOperand(0);
2339 V = DAG.getNode(ISD::XOR, N0.getDebugLoc(), V.getValueType(), V,
2340 DAG.getConstant(1, V.getValueType()));
2341 AddToWorkList(V.getNode());
2342 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, V);
2345 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are setcc
2346 if (N1C && N1C->getAPIntValue() == 1 && VT == MVT::i1 &&
2347 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
2348 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
2349 if (isOneUseSetCC(RHS) || isOneUseSetCC(LHS)) {
2350 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
2351 LHS = DAG.getNode(ISD::XOR, LHS.getDebugLoc(), VT, LHS, N1); // LHS = ~LHS
2352 RHS = DAG.getNode(ISD::XOR, RHS.getDebugLoc(), VT, RHS, N1); // RHS = ~RHS
2353 AddToWorkList(LHS.getNode()); AddToWorkList(RHS.getNode());
2354 return DAG.getNode(NewOpcode, N->getDebugLoc(), VT, LHS, RHS);
2357 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are constants
2358 if (N1C && N1C->isAllOnesValue() &&
2359 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
2360 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
2361 if (isa<ConstantSDNode>(RHS) || isa<ConstantSDNode>(LHS)) {
2362 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
2363 LHS = DAG.getNode(ISD::XOR, LHS.getDebugLoc(), VT, LHS, N1); // LHS = ~LHS
2364 RHS = DAG.getNode(ISD::XOR, RHS.getDebugLoc(), VT, RHS, N1); // RHS = ~RHS
2365 AddToWorkList(LHS.getNode()); AddToWorkList(RHS.getNode());
2366 return DAG.getNode(NewOpcode, N->getDebugLoc(), VT, LHS, RHS);
2369 // fold (xor (xor x, c1), c2) -> (xor x, (xor c1, c2))
2370 if (N1C && N0.getOpcode() == ISD::XOR) {
2371 ConstantSDNode *N00C = dyn_cast<ConstantSDNode>(N0.getOperand(0));
2372 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2374 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N0.getOperand(1),
2375 DAG.getConstant(N1C->getAPIntValue() ^
2376 N00C->getAPIntValue(), VT));
2378 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N0.getOperand(0),
2379 DAG.getConstant(N1C->getAPIntValue() ^
2380 N01C->getAPIntValue(), VT));
2382 // fold (xor x, x) -> 0
2384 if (!VT.isVector()) {
2385 return DAG.getConstant(0, VT);
2386 } else if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)){
2387 // Produce a vector of zeros.
2388 SDValue El = DAG.getConstant(0, VT.getVectorElementType());
2389 std::vector<SDValue> Ops(VT.getVectorNumElements(), El);
2390 return DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(), VT,
2391 &Ops[0], Ops.size());
2395 // Simplify: xor (op x...), (op y...) -> (op (xor x, y))
2396 if (N0.getOpcode() == N1.getOpcode()) {
2397 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
2398 if (Tmp.getNode()) return Tmp;
2401 // Simplify the expression using non-local knowledge.
2402 if (!VT.isVector() &&
2403 SimplifyDemandedBits(SDValue(N, 0)))
2404 return SDValue(N, 0);
2409 /// visitShiftByConstant - Handle transforms common to the three shifts, when
2410 /// the shift amount is a constant.
2411 SDValue DAGCombiner::visitShiftByConstant(SDNode *N, unsigned Amt) {
2412 SDNode *LHS = N->getOperand(0).getNode();
2413 if (!LHS->hasOneUse()) return SDValue();
2415 // We want to pull some binops through shifts, so that we have (and (shift))
2416 // instead of (shift (and)), likewise for add, or, xor, etc. This sort of
2417 // thing happens with address calculations, so it's important to canonicalize
2419 bool HighBitSet = false; // Can we transform this if the high bit is set?
2421 switch (LHS->getOpcode()) {
2422 default: return SDValue();
2425 HighBitSet = false; // We can only transform sra if the high bit is clear.
2428 HighBitSet = true; // We can only transform sra if the high bit is set.
2431 if (N->getOpcode() != ISD::SHL)
2432 return SDValue(); // only shl(add) not sr[al](add).
2433 HighBitSet = false; // We can only transform sra if the high bit is clear.
2437 // We require the RHS of the binop to be a constant as well.
2438 ConstantSDNode *BinOpCst = dyn_cast<ConstantSDNode>(LHS->getOperand(1));
2439 if (!BinOpCst) return SDValue();
2441 // FIXME: disable this unless the input to the binop is a shift by a constant.
2442 // If it is not a shift, it pessimizes some common cases like:
2444 // void foo(int *X, int i) { X[i & 1235] = 1; }
2445 // int bar(int *X, int i) { return X[i & 255]; }
2446 SDNode *BinOpLHSVal = LHS->getOperand(0).getNode();
2447 if ((BinOpLHSVal->getOpcode() != ISD::SHL &&
2448 BinOpLHSVal->getOpcode() != ISD::SRA &&
2449 BinOpLHSVal->getOpcode() != ISD::SRL) ||
2450 !isa<ConstantSDNode>(BinOpLHSVal->getOperand(1)))
2453 MVT VT = N->getValueType(0);
2455 // If this is a signed shift right, and the high bit is modified by the
2456 // logical operation, do not perform the transformation. The highBitSet
2457 // boolean indicates the value of the high bit of the constant which would
2458 // cause it to be modified for this operation.
2459 if (N->getOpcode() == ISD::SRA) {
2460 bool BinOpRHSSignSet = BinOpCst->getAPIntValue().isNegative();
2461 if (BinOpRHSSignSet != HighBitSet)
2465 // Fold the constants, shifting the binop RHS by the shift amount.
2466 SDValue NewRHS = DAG.getNode(N->getOpcode(), LHS->getOperand(1).getDebugLoc(),
2468 LHS->getOperand(1), N->getOperand(1));
2470 // Create the new shift.
2471 SDValue NewShift = DAG.getNode(N->getOpcode(), LHS->getOperand(0).getDebugLoc(),
2472 VT, LHS->getOperand(0), N->getOperand(1));
2474 // Create the new binop.
2475 return DAG.getNode(LHS->getOpcode(), N->getDebugLoc(), VT, NewShift, NewRHS);
2478 SDValue DAGCombiner::visitSHL(SDNode *N) {
2479 SDValue N0 = N->getOperand(0);
2480 SDValue N1 = N->getOperand(1);
2481 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2482 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2483 MVT VT = N0.getValueType();
2484 unsigned OpSizeInBits = VT.getSizeInBits();
2486 // fold (shl c1, c2) -> c1<<c2
2488 return DAG.FoldConstantArithmetic(ISD::SHL, VT, N0C, N1C);
2489 // fold (shl 0, x) -> 0
2490 if (N0C && N0C->isNullValue())
2492 // fold (shl x, c >= size(x)) -> undef
2493 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
2494 return DAG.getUNDEF(VT);
2495 // fold (shl x, 0) -> x
2496 if (N1C && N1C->isNullValue())
2498 // if (shl x, c) is known to be zero, return 0
2499 if (DAG.MaskedValueIsZero(SDValue(N, 0),
2500 APInt::getAllOnesValue(VT.getSizeInBits())))
2501 return DAG.getConstant(0, VT);
2502 // fold (shl x, (trunc (and y, c))) -> (shl x, (and (trunc y), (trunc c))).
2503 if (N1.getOpcode() == ISD::TRUNCATE &&
2504 N1.getOperand(0).getOpcode() == ISD::AND &&
2505 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
2506 SDValue N101 = N1.getOperand(0).getOperand(1);
2507 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
2508 MVT TruncVT = N1.getValueType();
2509 SDValue N100 = N1.getOperand(0).getOperand(0);
2510 APInt TruncC = N101C->getAPIntValue();
2511 TruncC.trunc(TruncVT.getSizeInBits());
2512 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0,
2513 DAG.getNode(ISD::AND, N->getDebugLoc(), TruncVT,
2514 DAG.getNode(ISD::TRUNCATE,
2517 DAG.getConstant(TruncC, TruncVT)));
2521 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
2522 return SDValue(N, 0);
2524 // fold (shl (shl x, c1), c2) -> 0 or (shl x, (add c1, c2))
2525 if (N1C && N0.getOpcode() == ISD::SHL &&
2526 N0.getOperand(1).getOpcode() == ISD::Constant) {
2527 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
2528 uint64_t c2 = N1C->getZExtValue();
2529 if (c1 + c2 > OpSizeInBits)
2530 return DAG.getConstant(0, VT);
2531 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0.getOperand(0),
2532 DAG.getConstant(c1 + c2, N1.getValueType()));
2534 // fold (shl (srl x, c1), c2) -> (shl (and x, (shl -1, c1)), (sub c2, c1)) or
2535 // (srl (and x, (shl -1, c1)), (sub c1, c2))
2536 if (N1C && N0.getOpcode() == ISD::SRL &&
2537 N0.getOperand(1).getOpcode() == ISD::Constant) {
2538 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
2539 uint64_t c2 = N1C->getZExtValue();
2540 SDValue Mask = DAG.getNode(ISD::AND, N0.getDebugLoc(), VT, N0.getOperand(0),
2541 DAG.getConstant(~0ULL << c1, VT));
2543 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, Mask,
2544 DAG.getConstant(c2-c1, N1.getValueType()));
2546 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, Mask,
2547 DAG.getConstant(c1-c2, N1.getValueType()));
2549 // fold (shl (sra x, c1), c1) -> (and x, (shl -1, c1))
2550 if (N1C && N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1))
2551 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0.getOperand(0),
2552 DAG.getConstant(~0ULL << N1C->getZExtValue(), VT));
2554 return N1C ? visitShiftByConstant(N, N1C->getZExtValue()) : SDValue();
2557 SDValue DAGCombiner::visitSRA(SDNode *N) {
2558 SDValue N0 = N->getOperand(0);
2559 SDValue N1 = N->getOperand(1);
2560 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2561 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2562 MVT VT = N0.getValueType();
2564 // fold (sra c1, c2) -> (sra c1, c2)
2566 return DAG.FoldConstantArithmetic(ISD::SRA, VT, N0C, N1C);
2567 // fold (sra 0, x) -> 0
2568 if (N0C && N0C->isNullValue())
2570 // fold (sra -1, x) -> -1
2571 if (N0C && N0C->isAllOnesValue())
2573 // fold (sra x, (setge c, size(x))) -> undef
2574 if (N1C && N1C->getZExtValue() >= VT.getSizeInBits())
2575 return DAG.getUNDEF(VT);
2576 // fold (sra x, 0) -> x
2577 if (N1C && N1C->isNullValue())
2579 // fold (sra (shl x, c1), c1) -> sext_inreg for some c1 and target supports
2581 if (N1C && N0.getOpcode() == ISD::SHL && N1 == N0.getOperand(1)) {
2582 unsigned LowBits = VT.getSizeInBits() - (unsigned)N1C->getZExtValue();
2583 MVT EVT = MVT::getIntegerVT(LowBits);
2584 if ((!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, EVT)))
2585 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT,
2586 N0.getOperand(0), DAG.getValueType(EVT));
2589 // fold (sra (sra x, c1), c2) -> (sra x, (add c1, c2))
2590 if (N1C && N0.getOpcode() == ISD::SRA) {
2591 if (ConstantSDNode *C1 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
2592 unsigned Sum = N1C->getZExtValue() + C1->getZExtValue();
2593 if (Sum >= VT.getSizeInBits()) Sum = VT.getSizeInBits()-1;
2594 return DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, N0.getOperand(0),
2595 DAG.getConstant(Sum, N1C->getValueType(0)));
2599 // fold (sra (shl X, m), (sub result_size, n))
2600 // -> (sign_extend (trunc (shl X, (sub (sub result_size, n), m)))) for
2601 // result_size - n != m.
2602 // If truncate is free for the target sext(shl) is likely to result in better
2604 if (N0.getOpcode() == ISD::SHL) {
2605 // Get the two constanst of the shifts, CN0 = m, CN = n.
2606 const ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2608 // Determine what the truncate's result bitsize and type would be.
2609 unsigned VTValSize = VT.getSizeInBits();
2611 MVT::getIntegerVT(VTValSize - N1C->getZExtValue());
2612 // Determine the residual right-shift amount.
2613 unsigned ShiftAmt = N1C->getZExtValue() - N01C->getZExtValue();
2615 // If the shift is not a no-op (in which case this should be just a sign
2616 // extend already), the truncated to type is legal, sign_extend is legal
2617 // on that type, and the the truncate to that type is both legal and free,
2618 // perform the transform.
2620 TLI.isOperationLegalOrCustom(ISD::SIGN_EXTEND, TruncVT) &&
2621 TLI.isOperationLegalOrCustom(ISD::TRUNCATE, VT) &&
2622 TLI.isTruncateFree(VT, TruncVT)) {
2624 SDValue Amt = DAG.getConstant(ShiftAmt, getShiftAmountTy());
2625 SDValue Shift = DAG.getNode(ISD::SRL, N0.getDebugLoc(), VT,
2626 N0.getOperand(0), Amt);
2627 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(), TruncVT,
2629 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(),
2630 N->getValueType(0), Trunc);
2635 // fold (sra x, (trunc (and y, c))) -> (sra x, (and (trunc y), (trunc c))).
2636 if (N1.getOpcode() == ISD::TRUNCATE &&
2637 N1.getOperand(0).getOpcode() == ISD::AND &&
2638 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
2639 SDValue N101 = N1.getOperand(0).getOperand(1);
2640 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
2641 MVT TruncVT = N1.getValueType();
2642 SDValue N100 = N1.getOperand(0).getOperand(0);
2643 APInt TruncC = N101C->getAPIntValue();
2644 TruncC.trunc(TruncVT.getSizeInBits());
2645 return DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, N0,
2646 DAG.getNode(ISD::AND, N->getDebugLoc(),
2648 DAG.getNode(ISD::TRUNCATE,
2651 DAG.getConstant(TruncC, TruncVT)));
2655 // Simplify, based on bits shifted out of the LHS.
2656 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
2657 return SDValue(N, 0);
2660 // If the sign bit is known to be zero, switch this to a SRL.
2661 if (DAG.SignBitIsZero(N0))
2662 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0, N1);
2664 return N1C ? visitShiftByConstant(N, N1C->getZExtValue()) : SDValue();
2667 SDValue DAGCombiner::visitSRL(SDNode *N) {
2668 SDValue N0 = N->getOperand(0);
2669 SDValue N1 = N->getOperand(1);
2670 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2671 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2672 MVT VT = N0.getValueType();
2673 unsigned OpSizeInBits = VT.getSizeInBits();
2675 // fold (srl c1, c2) -> c1 >>u c2
2677 return DAG.FoldConstantArithmetic(ISD::SRL, VT, N0C, N1C);
2678 // fold (srl 0, x) -> 0
2679 if (N0C && N0C->isNullValue())
2681 // fold (srl x, c >= size(x)) -> undef
2682 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
2683 return DAG.getUNDEF(VT);
2684 // fold (srl x, 0) -> x
2685 if (N1C && N1C->isNullValue())
2687 // if (srl x, c) is known to be zero, return 0
2688 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
2689 APInt::getAllOnesValue(OpSizeInBits)))
2690 return DAG.getConstant(0, VT);
2692 // fold (srl (srl x, c1), c2) -> 0 or (srl x, (add c1, c2))
2693 if (N1C && N0.getOpcode() == ISD::SRL &&
2694 N0.getOperand(1).getOpcode() == ISD::Constant) {
2695 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
2696 uint64_t c2 = N1C->getZExtValue();
2697 if (c1 + c2 > OpSizeInBits)
2698 return DAG.getConstant(0, VT);
2699 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0.getOperand(0),
2700 DAG.getConstant(c1 + c2, N1.getValueType()));
2703 // fold (srl (anyextend x), c) -> (anyextend (srl x, c))
2704 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
2705 // Shifting in all undef bits?
2706 MVT SmallVT = N0.getOperand(0).getValueType();
2707 if (N1C->getZExtValue() >= SmallVT.getSizeInBits())
2708 return DAG.getUNDEF(VT);
2710 SDValue SmallShift = DAG.getNode(ISD::SRL, N0.getDebugLoc(), SmallVT,
2711 N0.getOperand(0), N1);
2712 AddToWorkList(SmallShift.getNode());
2713 return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, SmallShift);
2716 // fold (srl (sra X, Y), 31) -> (srl X, 31). This srl only looks at the sign
2717 // bit, which is unmodified by sra.
2718 if (N1C && N1C->getZExtValue() + 1 == VT.getSizeInBits()) {
2719 if (N0.getOpcode() == ISD::SRA)
2720 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0.getOperand(0), N1);
2723 // fold (srl (ctlz x), "5") -> x iff x has one bit set (the low bit).
2724 if (N1C && N0.getOpcode() == ISD::CTLZ &&
2725 N1C->getAPIntValue() == Log2_32(VT.getSizeInBits())) {
2726 APInt KnownZero, KnownOne;
2727 APInt Mask = APInt::getAllOnesValue(VT.getSizeInBits());
2728 DAG.ComputeMaskedBits(N0.getOperand(0), Mask, KnownZero, KnownOne);
2730 // If any of the input bits are KnownOne, then the input couldn't be all
2731 // zeros, thus the result of the srl will always be zero.
2732 if (KnownOne.getBoolValue()) return DAG.getConstant(0, VT);
2734 // If all of the bits input the to ctlz node are known to be zero, then
2735 // the result of the ctlz is "32" and the result of the shift is one.
2736 APInt UnknownBits = ~KnownZero & Mask;
2737 if (UnknownBits == 0) return DAG.getConstant(1, VT);
2739 // Otherwise, check to see if there is exactly one bit input to the ctlz.
2740 if ((UnknownBits & (UnknownBits - 1)) == 0) {
2741 // Okay, we know that only that the single bit specified by UnknownBits
2742 // could be set on input to the CTLZ node. If this bit is set, the SRL
2743 // will return 0, if it is clear, it returns 1. Change the CTLZ/SRL pair
2744 // to an SRL/XOR pair, which is likely to simplify more.
2745 unsigned ShAmt = UnknownBits.countTrailingZeros();
2746 SDValue Op = N0.getOperand(0);
2749 Op = DAG.getNode(ISD::SRL, N0.getDebugLoc(), VT, Op,
2750 DAG.getConstant(ShAmt, getShiftAmountTy()));
2751 AddToWorkList(Op.getNode());
2754 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT,
2755 Op, DAG.getConstant(1, VT));
2759 // fold (srl x, (trunc (and y, c))) -> (srl x, (and (trunc y), (trunc c))).
2760 if (N1.getOpcode() == ISD::TRUNCATE &&
2761 N1.getOperand(0).getOpcode() == ISD::AND &&
2762 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
2763 SDValue N101 = N1.getOperand(0).getOperand(1);
2764 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
2765 MVT TruncVT = N1.getValueType();
2766 SDValue N100 = N1.getOperand(0).getOperand(0);
2767 APInt TruncC = N101C->getAPIntValue();
2768 TruncC.trunc(TruncVT.getSizeInBits());
2769 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0,
2770 DAG.getNode(ISD::AND, N->getDebugLoc(),
2772 DAG.getNode(ISD::TRUNCATE,
2775 DAG.getConstant(TruncC, TruncVT)));
2779 // fold operands of srl based on knowledge that the low bits are not
2781 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
2782 return SDValue(N, 0);
2784 return N1C ? visitShiftByConstant(N, N1C->getZExtValue()) : SDValue();
2787 SDValue DAGCombiner::visitCTLZ(SDNode *N) {
2788 SDValue N0 = N->getOperand(0);
2789 MVT VT = N->getValueType(0);
2791 // fold (ctlz c1) -> c2
2792 if (isa<ConstantSDNode>(N0))
2793 return DAG.getNode(ISD::CTLZ, N->getDebugLoc(), VT, N0);
2797 SDValue DAGCombiner::visitCTTZ(SDNode *N) {
2798 SDValue N0 = N->getOperand(0);
2799 MVT VT = N->getValueType(0);
2801 // fold (cttz c1) -> c2
2802 if (isa<ConstantSDNode>(N0))
2803 return DAG.getNode(ISD::CTTZ, N->getDebugLoc(), VT, N0);
2807 SDValue DAGCombiner::visitCTPOP(SDNode *N) {
2808 SDValue N0 = N->getOperand(0);
2809 MVT VT = N->getValueType(0);
2811 // fold (ctpop c1) -> c2
2812 if (isa<ConstantSDNode>(N0))
2813 return DAG.getNode(ISD::CTPOP, N->getDebugLoc(), VT, N0);
2817 SDValue DAGCombiner::visitSELECT(SDNode *N) {
2818 SDValue N0 = N->getOperand(0);
2819 SDValue N1 = N->getOperand(1);
2820 SDValue N2 = N->getOperand(2);
2821 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2822 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2823 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2);
2824 MVT VT = N->getValueType(0);
2825 MVT VT0 = N0.getValueType();
2827 // fold (select C, X, X) -> X
2830 // fold (select true, X, Y) -> X
2831 if (N0C && !N0C->isNullValue())
2833 // fold (select false, X, Y) -> Y
2834 if (N0C && N0C->isNullValue())
2836 // fold (select C, 1, X) -> (or C, X)
2837 if (VT == MVT::i1 && N1C && N1C->getAPIntValue() == 1)
2838 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N2);
2839 // fold (select C, 0, 1) -> (xor C, 1)
2840 if (VT.isInteger() &&
2843 TLI.getBooleanContents() == TargetLowering::ZeroOrOneBooleanContent)) &&
2844 N1C && N2C && N1C->isNullValue() && N2C->getAPIntValue() == 1) {
2847 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT0,
2848 N0, DAG.getConstant(1, VT0));
2849 XORNode = DAG.getNode(ISD::XOR, N0.getDebugLoc(), VT0,
2850 N0, DAG.getConstant(1, VT0));
2851 AddToWorkList(XORNode.getNode());
2853 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, XORNode);
2854 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, XORNode);
2856 // fold (select C, 0, X) -> (and (not C), X)
2857 if (VT == VT0 && VT == MVT::i1 && N1C && N1C->isNullValue()) {
2858 SDValue NOTNode = DAG.getNOT(N0.getDebugLoc(), N0, VT);
2859 AddToWorkList(NOTNode.getNode());
2860 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, NOTNode, N2);
2862 // fold (select C, X, 1) -> (or (not C), X)
2863 if (VT == VT0 && VT == MVT::i1 && N2C && N2C->getAPIntValue() == 1) {
2864 SDValue NOTNode = DAG.getNOT(N0.getDebugLoc(), N0, VT);
2865 AddToWorkList(NOTNode.getNode());
2866 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, NOTNode, N1);
2868 // fold (select C, X, 0) -> (and C, X)
2869 if (VT == MVT::i1 && N2C && N2C->isNullValue())
2870 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0, N1);
2871 // fold (select X, X, Y) -> (or X, Y)
2872 // fold (select X, 1, Y) -> (or X, Y)
2873 if (VT == MVT::i1 && (N0 == N1 || (N1C && N1C->getAPIntValue() == 1)))
2874 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N2);
2875 // fold (select X, Y, X) -> (and X, Y)
2876 // fold (select X, Y, 0) -> (and X, Y)
2877 if (VT == MVT::i1 && (N0 == N2 || (N2C && N2C->getAPIntValue() == 0)))
2878 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0, N1);
2880 // If we can fold this based on the true/false value, do so.
2881 if (SimplifySelectOps(N, N1, N2))
2882 return SDValue(N, 0); // Don't revisit N.
2884 // fold selects based on a setcc into other things, such as min/max/abs
2885 if (N0.getOpcode() == ISD::SETCC) {
2887 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
2888 // having to say they don't support SELECT_CC on every type the DAG knows
2889 // about, since there is no way to mark an opcode illegal at all value types
2890 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other))
2891 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT,
2892 N0.getOperand(0), N0.getOperand(1),
2893 N1, N2, N0.getOperand(2));
2895 return SimplifySelect(N->getDebugLoc(), N0, N1, N2);
2901 SDValue DAGCombiner::visitSELECT_CC(SDNode *N) {
2902 SDValue N0 = N->getOperand(0);
2903 SDValue N1 = N->getOperand(1);
2904 SDValue N2 = N->getOperand(2);
2905 SDValue N3 = N->getOperand(3);
2906 SDValue N4 = N->getOperand(4);
2907 ISD::CondCode CC = cast<CondCodeSDNode>(N4)->get();
2909 // fold select_cc lhs, rhs, x, x, cc -> x
2913 // Determine if the condition we're dealing with is constant
2914 SDValue SCC = SimplifySetCC(TLI.getSetCCResultType(N0.getValueType()),
2915 N0, N1, CC, N->getDebugLoc(), false);
2916 if (SCC.getNode()) AddToWorkList(SCC.getNode());
2918 if (ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.getNode())) {
2919 if (!SCCC->isNullValue())
2920 return N2; // cond always true -> true val
2922 return N3; // cond always false -> false val
2925 // Fold to a simpler select_cc
2926 if (SCC.getNode() && SCC.getOpcode() == ISD::SETCC)
2927 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), N2.getValueType(),
2928 SCC.getOperand(0), SCC.getOperand(1), N2, N3,
2931 // If we can fold this based on the true/false value, do so.
2932 if (SimplifySelectOps(N, N2, N3))
2933 return SDValue(N, 0); // Don't revisit N.
2935 // fold select_cc into other things, such as min/max/abs
2936 return SimplifySelectCC(N->getDebugLoc(), N0, N1, N2, N3, CC);
2939 SDValue DAGCombiner::visitSETCC(SDNode *N) {
2940 return SimplifySetCC(N->getValueType(0), N->getOperand(0), N->getOperand(1),
2941 cast<CondCodeSDNode>(N->getOperand(2))->get(),
2945 // ExtendUsesToFormExtLoad - Trying to extend uses of a load to enable this:
2946 // "fold ({s|z}ext (load x)) -> ({s|z}ext (truncate ({s|z}extload x)))"
2947 // transformation. Returns true if extension are possible and the above
2948 // mentioned transformation is profitable.
2949 static bool ExtendUsesToFormExtLoad(SDNode *N, SDValue N0,
2951 SmallVector<SDNode*, 4> &ExtendNodes,
2952 const TargetLowering &TLI) {
2953 bool HasCopyToRegUses = false;
2954 bool isTruncFree = TLI.isTruncateFree(N->getValueType(0), N0.getValueType());
2955 for (SDNode::use_iterator UI = N0.getNode()->use_begin(),
2956 UE = N0.getNode()->use_end();
2961 // FIXME: Only extend SETCC N, N and SETCC N, c for now.
2962 if (User->getOpcode() == ISD::SETCC) {
2963 ISD::CondCode CC = cast<CondCodeSDNode>(User->getOperand(2))->get();
2964 if (ExtOpc == ISD::ZERO_EXTEND && ISD::isSignedIntSetCC(CC))
2965 // Sign bits will be lost after a zext.
2968 for (unsigned i = 0; i != 2; ++i) {
2969 SDValue UseOp = User->getOperand(i);
2972 if (!isa<ConstantSDNode>(UseOp))
2977 ExtendNodes.push_back(User);
2979 for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) {
2980 SDValue UseOp = User->getOperand(i);
2982 // If truncate from extended type to original load type is free
2983 // on this target, then it's ok to extend a CopyToReg.
2984 if (isTruncFree && User->getOpcode() == ISD::CopyToReg)
2985 HasCopyToRegUses = true;
2993 if (HasCopyToRegUses) {
2994 bool BothLiveOut = false;
2995 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
2998 for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) {
2999 SDValue UseOp = User->getOperand(i);
3000 if (UseOp.getNode() == N && UseOp.getResNo() == 0) {
3007 // Both unextended and extended values are live out. There had better be
3008 // good a reason for the transformation.
3009 return ExtendNodes.size();
3014 SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
3015 SDValue N0 = N->getOperand(0);
3016 MVT VT = N->getValueType(0);
3018 // fold (sext c1) -> c1
3019 if (isa<ConstantSDNode>(N0))
3020 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, N0);
3022 // fold (sext (sext x)) -> (sext x)
3023 // fold (sext (aext x)) -> (sext x)
3024 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
3025 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT,
3028 if (N0.getOpcode() == ISD::TRUNCATE) {
3029 // fold (sext (truncate (load x))) -> (sext (smaller load x))
3030 // fold (sext (truncate (srl (load x), c))) -> (sext (smaller load (x+c/n)))
3031 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
3032 if (NarrowLoad.getNode()) {
3033 if (NarrowLoad.getNode() != N0.getNode())
3034 CombineTo(N0.getNode(), NarrowLoad);
3035 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, NarrowLoad);
3038 // See if the value being truncated is already sign extended. If so, just
3039 // eliminate the trunc/sext pair.
3040 SDValue Op = N0.getOperand(0);
3041 unsigned OpBits = Op.getValueType().getSizeInBits();
3042 unsigned MidBits = N0.getValueType().getSizeInBits();
3043 unsigned DestBits = VT.getSizeInBits();
3044 unsigned NumSignBits = DAG.ComputeNumSignBits(Op);
3046 if (OpBits == DestBits) {
3047 // Op is i32, Mid is i8, and Dest is i32. If Op has more than 24 sign
3048 // bits, it is already ready.
3049 if (NumSignBits > DestBits-MidBits)
3051 } else if (OpBits < DestBits) {
3052 // Op is i32, Mid is i8, and Dest is i64. If Op has more than 24 sign
3053 // bits, just sext from i32.
3054 if (NumSignBits > OpBits-MidBits)
3055 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, Op);
3057 // Op is i64, Mid is i8, and Dest is i32. If Op has more than 56 sign
3058 // bits, just truncate to i32.
3059 if (NumSignBits > OpBits-MidBits)
3060 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, Op);
3063 // fold (sext (truncate x)) -> (sextinreg x).
3064 if (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG,
3065 N0.getValueType())) {
3066 if (Op.getValueType().bitsLT(VT))
3067 Op = DAG.getNode(ISD::ANY_EXTEND, N0.getDebugLoc(), VT, Op);
3068 else if (Op.getValueType().bitsGT(VT))
3069 Op = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(), VT, Op);
3070 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT, Op,
3071 DAG.getValueType(N0.getValueType()));
3075 // fold (sext (load x)) -> (sext (truncate (sextload x)))
3076 if (ISD::isNON_EXTLoad(N0.getNode()) &&
3077 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
3078 TLI.isLoadExtLegal(ISD::SEXTLOAD, N0.getValueType()))) {
3079 bool DoXform = true;
3080 SmallVector<SDNode*, 4> SetCCs;
3081 if (!N0.hasOneUse())
3082 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::SIGN_EXTEND, SetCCs, TLI);
3084 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3085 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, N->getDebugLoc(),
3086 VT, LN0->getChain(),
3087 LN0->getBasePtr(), LN0->getSrcValue(),
3088 LN0->getSrcValueOffset(),
3090 LN0->isVolatile(), LN0->getAlignment());
3091 CombineTo(N, ExtLoad);
3092 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
3093 N0.getValueType(), ExtLoad);
3094 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
3096 // Extend SetCC uses if necessary.
3097 for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
3098 SDNode *SetCC = SetCCs[i];
3099 SmallVector<SDValue, 4> Ops;
3101 for (unsigned j = 0; j != 2; ++j) {
3102 SDValue SOp = SetCC->getOperand(j);
3104 Ops.push_back(ExtLoad);
3106 Ops.push_back(DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(),
3110 Ops.push_back(SetCC->getOperand(2));
3111 CombineTo(SetCC, DAG.getNode(ISD::SETCC, N->getDebugLoc(),
3112 SetCC->getValueType(0),
3113 &Ops[0], Ops.size()));
3116 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3120 // fold (sext (sextload x)) -> (sext (truncate (sextload x)))
3121 // fold (sext ( extload x)) -> (sext (truncate (sextload x)))
3122 if ((ISD::isSEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
3123 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
3124 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3125 MVT EVT = LN0->getMemoryVT();
3126 if ((!LegalOperations && !LN0->isVolatile()) ||
3127 TLI.isLoadExtLegal(ISD::SEXTLOAD, EVT)) {
3128 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, N->getDebugLoc(), VT,
3130 LN0->getBasePtr(), LN0->getSrcValue(),
3131 LN0->getSrcValueOffset(), EVT,
3132 LN0->isVolatile(), LN0->getAlignment());
3133 CombineTo(N, ExtLoad);
3134 CombineTo(N0.getNode(),
3135 DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
3136 N0.getValueType(), ExtLoad),
3137 ExtLoad.getValue(1));
3138 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3142 // sext(setcc x, y, cc) -> (select_cc x, y, -1, 0, cc)
3143 if (N0.getOpcode() == ISD::SETCC) {
3145 SimplifySelectCC(N->getDebugLoc(), N0.getOperand(0), N0.getOperand(1),
3146 DAG.getConstant(~0ULL, VT), DAG.getConstant(0, VT),
3147 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
3148 if (SCC.getNode()) return SCC;
3151 // fold (sext x) -> (zext x) if the sign bit is known zero.
3152 if ((!LegalOperations || TLI.isOperationLegal(ISD::ZERO_EXTEND, VT)) &&
3153 DAG.SignBitIsZero(N0))
3154 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, N0);
3159 SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) {
3160 SDValue N0 = N->getOperand(0);
3161 MVT VT = N->getValueType(0);
3163 // fold (zext c1) -> c1
3164 if (isa<ConstantSDNode>(N0))
3165 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, N0);
3166 // fold (zext (zext x)) -> (zext x)
3167 // fold (zext (aext x)) -> (zext x)
3168 if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
3169 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT,
3172 // fold (zext (truncate (load x))) -> (zext (smaller load x))
3173 // fold (zext (truncate (srl (load x), c))) -> (zext (small load (x+c/n)))
3174 if (N0.getOpcode() == ISD::TRUNCATE) {
3175 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
3176 if (NarrowLoad.getNode()) {
3177 if (NarrowLoad.getNode() != N0.getNode())
3178 CombineTo(N0.getNode(), NarrowLoad);
3179 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, NarrowLoad);
3183 // fold (zext (truncate x)) -> (and x, mask)
3184 if (N0.getOpcode() == ISD::TRUNCATE &&
3185 (!LegalOperations || TLI.isOperationLegal(ISD::AND, VT))) {
3186 SDValue Op = N0.getOperand(0);
3187 if (Op.getValueType().bitsLT(VT)) {
3188 Op = DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, Op);
3189 } else if (Op.getValueType().bitsGT(VT)) {
3190 Op = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, Op);
3192 return DAG.getZeroExtendInReg(Op, N->getDebugLoc(), N0.getValueType());
3195 // fold (zext (and (trunc x), cst)) -> (and x, cst).
3196 if (N0.getOpcode() == ISD::AND &&
3197 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
3198 N0.getOperand(1).getOpcode() == ISD::Constant) {
3199 SDValue X = N0.getOperand(0).getOperand(0);
3200 if (X.getValueType().bitsLT(VT)) {
3201 X = DAG.getNode(ISD::ANY_EXTEND, X.getDebugLoc(), VT, X);
3202 } else if (X.getValueType().bitsGT(VT)) {
3203 X = DAG.getNode(ISD::TRUNCATE, X.getDebugLoc(), VT, X);
3205 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
3206 Mask.zext(VT.getSizeInBits());
3207 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
3208 X, DAG.getConstant(Mask, VT));
3211 // fold (zext (load x)) -> (zext (truncate (zextload x)))
3212 if (ISD::isNON_EXTLoad(N0.getNode()) &&
3213 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
3214 TLI.isLoadExtLegal(ISD::ZEXTLOAD, N0.getValueType()))) {
3215 bool DoXform = true;
3216 SmallVector<SDNode*, 4> SetCCs;
3217 if (!N0.hasOneUse())
3218 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ZERO_EXTEND, SetCCs, TLI);
3220 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3221 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, N->getDebugLoc(), VT,
3223 LN0->getBasePtr(), LN0->getSrcValue(),
3224 LN0->getSrcValueOffset(),
3226 LN0->isVolatile(), LN0->getAlignment());
3227 CombineTo(N, ExtLoad);
3228 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
3229 N0.getValueType(), ExtLoad);
3230 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
3232 // Extend SetCC uses if necessary.
3233 for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
3234 SDNode *SetCC = SetCCs[i];
3235 SmallVector<SDValue, 4> Ops;
3237 for (unsigned j = 0; j != 2; ++j) {
3238 SDValue SOp = SetCC->getOperand(j);
3240 Ops.push_back(ExtLoad);
3242 Ops.push_back(DAG.getNode(ISD::ZERO_EXTEND,
3243 N->getDebugLoc(), VT, SOp));
3246 Ops.push_back(SetCC->getOperand(2));
3247 CombineTo(SetCC, DAG.getNode(ISD::SETCC, N->getDebugLoc(),
3248 SetCC->getValueType(0),
3249 &Ops[0], Ops.size()));
3252 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3256 // fold (zext (zextload x)) -> (zext (truncate (zextload x)))
3257 // fold (zext ( extload x)) -> (zext (truncate (zextload x)))
3258 if ((ISD::isZEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
3259 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
3260 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3261 MVT EVT = LN0->getMemoryVT();
3262 if ((!LegalOperations && !LN0->isVolatile()) ||
3263 TLI.isLoadExtLegal(ISD::ZEXTLOAD, EVT)) {
3264 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, N->getDebugLoc(), VT,
3266 LN0->getBasePtr(), LN0->getSrcValue(),
3267 LN0->getSrcValueOffset(), EVT,
3268 LN0->isVolatile(), LN0->getAlignment());
3269 CombineTo(N, ExtLoad);
3270 CombineTo(N0.getNode(),
3271 DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(), N0.getValueType(),
3273 ExtLoad.getValue(1));
3274 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3278 // zext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
3279 if (N0.getOpcode() == ISD::SETCC) {
3281 SimplifySelectCC(N->getDebugLoc(), N0.getOperand(0), N0.getOperand(1),
3282 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
3283 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
3284 if (SCC.getNode()) return SCC;
3290 SDValue DAGCombiner::visitANY_EXTEND(SDNode *N) {
3291 SDValue N0 = N->getOperand(0);
3292 MVT VT = N->getValueType(0);
3294 // fold (aext c1) -> c1
3295 if (isa<ConstantSDNode>(N0))
3296 return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, N0);
3297 // fold (aext (aext x)) -> (aext x)
3298 // fold (aext (zext x)) -> (zext x)
3299 // fold (aext (sext x)) -> (sext x)
3300 if (N0.getOpcode() == ISD::ANY_EXTEND ||
3301 N0.getOpcode() == ISD::ZERO_EXTEND ||
3302 N0.getOpcode() == ISD::SIGN_EXTEND)
3303 return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT, N0.getOperand(0));
3305 // fold (aext (truncate (load x))) -> (aext (smaller load x))
3306 // fold (aext (truncate (srl (load x), c))) -> (aext (small load (x+c/n)))
3307 if (N0.getOpcode() == ISD::TRUNCATE) {
3308 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
3309 if (NarrowLoad.getNode()) {
3310 if (NarrowLoad.getNode() != N0.getNode())
3311 CombineTo(N0.getNode(), NarrowLoad);
3312 return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, NarrowLoad);
3316 // fold (aext (truncate x))
3317 if (N0.getOpcode() == ISD::TRUNCATE) {
3318 SDValue TruncOp = N0.getOperand(0);
3319 if (TruncOp.getValueType() == VT)
3320 return TruncOp; // x iff x size == zext size.
3321 if (TruncOp.getValueType().bitsGT(VT))
3322 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, TruncOp);
3323 return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, TruncOp);
3326 // fold (aext (and (trunc x), cst)) -> (and x, cst).
3327 if (N0.getOpcode() == ISD::AND &&
3328 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
3329 N0.getOperand(1).getOpcode() == ISD::Constant) {
3330 SDValue X = N0.getOperand(0).getOperand(0);
3331 if (X.getValueType().bitsLT(VT)) {
3332 X = DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, X);
3333 } else if (X.getValueType().bitsGT(VT)) {
3334 X = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, X);
3336 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
3337 Mask.zext(VT.getSizeInBits());
3338 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
3339 X, DAG.getConstant(Mask, VT));
3342 // fold (aext (load x)) -> (aext (truncate (extload x)))
3343 if (ISD::isNON_EXTLoad(N0.getNode()) && N0.hasOneUse() &&
3344 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
3345 TLI.isLoadExtLegal(ISD::EXTLOAD, N0.getValueType()))) {
3346 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3347 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, N->getDebugLoc(), VT,
3349 LN0->getBasePtr(), LN0->getSrcValue(),
3350 LN0->getSrcValueOffset(),
3352 LN0->isVolatile(), LN0->getAlignment());
3353 CombineTo(N, ExtLoad);
3354 // Redirect any chain users to the new load.
3355 DAG.ReplaceAllUsesOfValueWith(SDValue(LN0, 1),
3356 SDValue(ExtLoad.getNode(), 1));
3357 // If any node needs the original loaded value, recompute it.
3358 if (!LN0->use_empty())
3359 CombineTo(LN0, DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
3360 N0.getValueType(), ExtLoad),
3361 ExtLoad.getValue(1));
3362 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3365 // fold (aext (zextload x)) -> (aext (truncate (zextload x)))
3366 // fold (aext (sextload x)) -> (aext (truncate (sextload x)))
3367 // fold (aext ( extload x)) -> (aext (truncate (extload x)))
3368 if (N0.getOpcode() == ISD::LOAD &&
3369 !ISD::isNON_EXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
3371 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3372 MVT EVT = LN0->getMemoryVT();
3373 SDValue ExtLoad = DAG.getExtLoad(LN0->getExtensionType(), N->getDebugLoc(),
3374 VT, LN0->getChain(), LN0->getBasePtr(),
3376 LN0->getSrcValueOffset(), EVT,
3377 LN0->isVolatile(), LN0->getAlignment());
3378 CombineTo(N, ExtLoad);
3379 CombineTo(N0.getNode(),
3380 DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
3381 N0.getValueType(), ExtLoad),
3382 ExtLoad.getValue(1));
3383 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3386 // aext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
3387 if (N0.getOpcode() == ISD::SETCC) {
3389 SimplifySelectCC(N->getDebugLoc(), N0.getOperand(0), N0.getOperand(1),
3390 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
3391 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
3399 /// GetDemandedBits - See if the specified operand can be simplified with the
3400 /// knowledge that only the bits specified by Mask are used. If so, return the
3401 /// simpler operand, otherwise return a null SDValue.
3402 SDValue DAGCombiner::GetDemandedBits(SDValue V, const APInt &Mask) {
3403 switch (V.getOpcode()) {
3407 // If the LHS or RHS don't contribute bits to the or, drop them.
3408 if (DAG.MaskedValueIsZero(V.getOperand(0), Mask))
3409 return V.getOperand(1);
3410 if (DAG.MaskedValueIsZero(V.getOperand(1), Mask))
3411 return V.getOperand(0);
3414 // Only look at single-use SRLs.
3415 if (!V.getNode()->hasOneUse())
3417 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(V.getOperand(1))) {
3418 // See if we can recursively simplify the LHS.
3419 unsigned Amt = RHSC->getZExtValue();
3421 // Watch out for shift count overflow though.
3422 if (Amt >= Mask.getBitWidth()) break;
3423 APInt NewMask = Mask << Amt;
3424 SDValue SimplifyLHS = GetDemandedBits(V.getOperand(0), NewMask);
3425 if (SimplifyLHS.getNode())
3426 return DAG.getNode(ISD::SRL, V.getDebugLoc(), V.getValueType(),
3427 SimplifyLHS, V.getOperand(1));
3433 /// ReduceLoadWidth - If the result of a wider load is shifted to right of N
3434 /// bits and then truncated to a narrower type and where N is a multiple
3435 /// of number of bits of the narrower type, transform it to a narrower load
3436 /// from address + N / num of bits of new type. If the result is to be
3437 /// extended, also fold the extension to form a extending load.
3438 SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) {
3439 unsigned Opc = N->getOpcode();
3440 ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
3441 SDValue N0 = N->getOperand(0);
3442 MVT VT = N->getValueType(0);
3445 // This transformation isn't valid for vector loads.
3449 // Special case: SIGN_EXTEND_INREG is basically truncating to EVT then
3451 if (Opc == ISD::SIGN_EXTEND_INREG) {
3452 ExtType = ISD::SEXTLOAD;
3453 EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
3454 if (LegalOperations && !TLI.isLoadExtLegal(ISD::SEXTLOAD, EVT))
3458 unsigned EVTBits = EVT.getSizeInBits();
3460 if (N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
3461 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
3462 ShAmt = N01->getZExtValue();
3463 // Is the shift amount a multiple of size of VT?
3464 if ((ShAmt & (EVTBits-1)) == 0) {
3465 N0 = N0.getOperand(0);
3466 if (N0.getValueType().getSizeInBits() <= EVTBits)
3472 // Do not generate loads of non-round integer types since these can
3473 // be expensive (and would be wrong if the type is not byte sized).
3474 if (isa<LoadSDNode>(N0) && N0.hasOneUse() && EVT.isRound() &&
3475 cast<LoadSDNode>(N0)->getMemoryVT().getSizeInBits() > EVTBits &&
3476 // Do not change the width of a volatile load.
3477 !cast<LoadSDNode>(N0)->isVolatile()) {
3478 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3479 MVT PtrType = N0.getOperand(1).getValueType();
3481 // For big endian targets, we need to adjust the offset to the pointer to
3482 // load the correct bytes.
3483 if (TLI.isBigEndian()) {
3484 unsigned LVTStoreBits = LN0->getMemoryVT().getStoreSizeInBits();
3485 unsigned EVTStoreBits = EVT.getStoreSizeInBits();
3486 ShAmt = LVTStoreBits - EVTStoreBits - ShAmt;
3489 uint64_t PtrOff = ShAmt / 8;
3490 unsigned NewAlign = MinAlign(LN0->getAlignment(), PtrOff);
3491 SDValue NewPtr = DAG.getNode(ISD::ADD, LN0->getDebugLoc(),
3492 PtrType, LN0->getBasePtr(),
3493 DAG.getConstant(PtrOff, PtrType));
3494 AddToWorkList(NewPtr.getNode());
3496 SDValue Load = (ExtType == ISD::NON_EXTLOAD)
3497 ? DAG.getLoad(VT, N0.getDebugLoc(), LN0->getChain(), NewPtr,
3498 LN0->getSrcValue(), LN0->getSrcValueOffset() + PtrOff,
3499 LN0->isVolatile(), NewAlign)
3500 : DAG.getExtLoad(ExtType, N0.getDebugLoc(), VT, LN0->getChain(), NewPtr,
3501 LN0->getSrcValue(), LN0->getSrcValueOffset() + PtrOff,
3502 EVT, LN0->isVolatile(), NewAlign);
3504 // Replace the old load's chain with the new load's chain.
3505 WorkListRemover DeadNodes(*this);
3506 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1),
3509 // Return the new loaded value.
3516 SDValue DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
3517 SDValue N0 = N->getOperand(0);
3518 SDValue N1 = N->getOperand(1);
3519 MVT VT = N->getValueType(0);
3520 MVT EVT = cast<VTSDNode>(N1)->getVT();
3521 unsigned VTBits = VT.getSizeInBits();
3522 unsigned EVTBits = EVT.getSizeInBits();
3524 // fold (sext_in_reg c1) -> c1
3525 if (isa<ConstantSDNode>(N0) || N0.getOpcode() == ISD::UNDEF)
3526 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT, N0, N1);
3528 // If the input is already sign extended, just drop the extension.
3529 if (DAG.ComputeNumSignBits(N0) >= VT.getSizeInBits()-EVTBits+1)
3532 // fold (sext_in_reg (sext_in_reg x, VT2), VT1) -> (sext_in_reg x, minVT) pt2
3533 if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
3534 EVT.bitsLT(cast<VTSDNode>(N0.getOperand(1))->getVT())) {
3535 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT,
3536 N0.getOperand(0), N1);
3539 // fold (sext_in_reg (sext x)) -> (sext x)
3540 // fold (sext_in_reg (aext x)) -> (sext x)
3541 // if x is small enough.
3542 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND) {
3543 SDValue N00 = N0.getOperand(0);
3544 if (N00.getValueType().getSizeInBits() < EVTBits)
3545 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, N00, N1);
3548 // fold (sext_in_reg x) -> (zext_in_reg x) if the sign bit is known zero.
3549 if (DAG.MaskedValueIsZero(N0, APInt::getBitsSet(VTBits, EVTBits-1, EVTBits)))
3550 return DAG.getZeroExtendInReg(N0, N->getDebugLoc(), EVT);
3552 // fold operands of sext_in_reg based on knowledge that the top bits are not
3554 if (SimplifyDemandedBits(SDValue(N, 0)))
3555 return SDValue(N, 0);
3557 // fold (sext_in_reg (load x)) -> (smaller sextload x)
3558 // fold (sext_in_reg (srl (load x), c)) -> (smaller sextload (x+c/evtbits))
3559 SDValue NarrowLoad = ReduceLoadWidth(N);
3560 if (NarrowLoad.getNode())
3563 // fold (sext_in_reg (srl X, 24), i8) -> (sra X, 24)
3564 // fold (sext_in_reg (srl X, 23), i8) -> (sra X, 23) iff possible.
3565 // We already fold "(sext_in_reg (srl X, 25), i8) -> srl X, 25" above.
3566 if (N0.getOpcode() == ISD::SRL) {
3567 if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
3568 if (ShAmt->getZExtValue()+EVTBits <= VT.getSizeInBits()) {
3569 // We can turn this into an SRA iff the input to the SRL is already sign
3571 unsigned InSignBits = DAG.ComputeNumSignBits(N0.getOperand(0));
3572 if (VT.getSizeInBits()-(ShAmt->getZExtValue()+EVTBits) < InSignBits)
3573 return DAG.getNode(ISD::SRA, N->getDebugLoc(), VT,
3574 N0.getOperand(0), N0.getOperand(1));
3578 // fold (sext_inreg (extload x)) -> (sextload x)
3579 if (ISD::isEXTLoad(N0.getNode()) &&
3580 ISD::isUNINDEXEDLoad(N0.getNode()) &&
3581 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
3582 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
3583 TLI.isLoadExtLegal(ISD::SEXTLOAD, EVT))) {
3584 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3585 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, N->getDebugLoc(), VT,
3587 LN0->getBasePtr(), LN0->getSrcValue(),
3588 LN0->getSrcValueOffset(), EVT,
3589 LN0->isVolatile(), LN0->getAlignment());
3590 CombineTo(N, ExtLoad);
3591 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
3592 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3594 // fold (sext_inreg (zextload x)) -> (sextload x) iff load has one use
3595 if (ISD::isZEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
3597 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
3598 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
3599 TLI.isLoadExtLegal(ISD::SEXTLOAD, EVT))) {
3600 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3601 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, N->getDebugLoc(), VT,
3603 LN0->getBasePtr(), LN0->getSrcValue(),
3604 LN0->getSrcValueOffset(), EVT,
3605 LN0->isVolatile(), LN0->getAlignment());
3606 CombineTo(N, ExtLoad);
3607 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
3608 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3613 SDValue DAGCombiner::visitTRUNCATE(SDNode *N) {
3614 SDValue N0 = N->getOperand(0);
3615 MVT VT = N->getValueType(0);
3618 if (N0.getValueType() == N->getValueType(0))
3620 // fold (truncate c1) -> c1
3621 if (isa<ConstantSDNode>(N0))
3622 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, N0);
3623 // fold (truncate (truncate x)) -> (truncate x)
3624 if (N0.getOpcode() == ISD::TRUNCATE)
3625 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, N0.getOperand(0));
3626 // fold (truncate (ext x)) -> (ext x) or (truncate x) or x
3627 if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::SIGN_EXTEND||
3628 N0.getOpcode() == ISD::ANY_EXTEND) {
3629 if (N0.getOperand(0).getValueType().bitsLT(VT))
3630 // if the source is smaller than the dest, we still need an extend
3631 return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT,
3633 else if (N0.getOperand(0).getValueType().bitsGT(VT))
3634 // if the source is larger than the dest, than we just need the truncate
3635 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, N0.getOperand(0));
3637 // if the source and dest are the same type, we can drop both the extend
3639 return N0.getOperand(0);
3642 // See if we can simplify the input to this truncate through knowledge that
3643 // only the low bits are being used. For example "trunc (or (shl x, 8), y)"
3646 GetDemandedBits(N0, APInt::getLowBitsSet(N0.getValueSizeInBits(),
3647 VT.getSizeInBits()));
3648 if (Shorter.getNode())
3649 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, Shorter);
3651 // fold (truncate (load x)) -> (smaller load x)
3652 // fold (truncate (srl (load x), c)) -> (smaller load (x+c/evtbits))
3653 return ReduceLoadWidth(N);
3656 static SDNode *getBuildPairElt(SDNode *N, unsigned i) {
3657 SDValue Elt = N->getOperand(i);
3658 if (Elt.getOpcode() != ISD::MERGE_VALUES)
3659 return Elt.getNode();
3660 return Elt.getOperand(Elt.getResNo()).getNode();
3663 /// CombineConsecutiveLoads - build_pair (load, load) -> load
3664 /// if load locations are consecutive.
3665 SDValue DAGCombiner::CombineConsecutiveLoads(SDNode *N, MVT VT) {
3666 assert(N->getOpcode() == ISD::BUILD_PAIR);
3668 SDNode *LD1 = getBuildPairElt(N, 0);
3669 if (!ISD::isNON_EXTLoad(LD1) || !LD1->hasOneUse())
3671 MVT LD1VT = LD1->getValueType(0);
3672 SDNode *LD2 = getBuildPairElt(N, 1);
3673 const MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
3675 if (ISD::isNON_EXTLoad(LD2) &&
3677 // If both are volatile this would reduce the number of volatile loads.
3678 // If one is volatile it might be ok, but play conservative and bail out.
3679 !cast<LoadSDNode>(LD1)->isVolatile() &&
3680 !cast<LoadSDNode>(LD2)->isVolatile() &&
3681 TLI.isConsecutiveLoad(LD2, LD1, LD1VT.getSizeInBits()/8, 1, MFI)) {
3682 LoadSDNode *LD = cast<LoadSDNode>(LD1);
3683 unsigned Align = LD->getAlignment();
3684 unsigned NewAlign = TLI.getTargetData()->
3685 getABITypeAlignment(VT.getTypeForMVT());
3687 if (NewAlign <= Align &&
3688 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT)))
3689 return DAG.getLoad(VT, N->getDebugLoc(), LD->getChain(), LD->getBasePtr(),
3690 LD->getSrcValue(), LD->getSrcValueOffset(),
3697 SDValue DAGCombiner::visitBIT_CONVERT(SDNode *N) {
3698 SDValue N0 = N->getOperand(0);
3699 MVT VT = N->getValueType(0);
3701 // If the input is a BUILD_VECTOR with all constant elements, fold this now.
3702 // Only do this before legalize, since afterward the target may be depending
3703 // on the bitconvert.
3704 // First check to see if this is all constant.
3706 N0.getOpcode() == ISD::BUILD_VECTOR && N0.getNode()->hasOneUse() &&
3708 bool isSimple = true;
3709 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i)
3710 if (N0.getOperand(i).getOpcode() != ISD::UNDEF &&
3711 N0.getOperand(i).getOpcode() != ISD::Constant &&
3712 N0.getOperand(i).getOpcode() != ISD::ConstantFP) {
3717 MVT DestEltVT = N->getValueType(0).getVectorElementType();
3718 assert(!DestEltVT.isVector() &&
3719 "Element type of vector ValueType must not be vector!");
3721 return ConstantFoldBIT_CONVERTofBUILD_VECTOR(N0.getNode(), DestEltVT);
3724 // If the input is a constant, let getNode fold it.
3725 if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
3726 SDValue Res = DAG.getNode(ISD::BIT_CONVERT, N->getDebugLoc(), VT, N0);
3727 if (Res.getNode() != N) return Res;
3730 // (conv (conv x, t1), t2) -> (conv x, t2)
3731 if (N0.getOpcode() == ISD::BIT_CONVERT)
3732 return DAG.getNode(ISD::BIT_CONVERT, N->getDebugLoc(), VT,
3735 // fold (conv (load x)) -> (load (conv*)x)
3736 // If the resultant load doesn't need a higher alignment than the original!
3737 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
3738 // Do not change the width of a volatile load.
3739 !cast<LoadSDNode>(N0)->isVolatile() &&
3740 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT))) {
3741 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3742 unsigned Align = TLI.getTargetData()->
3743 getABITypeAlignment(VT.getTypeForMVT());
3744 unsigned OrigAlign = LN0->getAlignment();
3746 if (Align <= OrigAlign) {
3747 SDValue Load = DAG.getLoad(VT, N->getDebugLoc(), LN0->getChain(),
3749 LN0->getSrcValue(), LN0->getSrcValueOffset(),
3750 LN0->isVolatile(), OrigAlign);
3752 CombineTo(N0.getNode(),
3753 DAG.getNode(ISD::BIT_CONVERT, N0.getDebugLoc(),
3754 N0.getValueType(), Load),
3760 // fold (bitconvert (fneg x)) -> (xor (bitconvert x), signbit)
3761 // fold (bitconvert (fabs x)) -> (and (bitconvert x), (not signbit))
3762 // This often reduces constant pool loads.
3763 if ((N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FABS) &&
3764 N0.getNode()->hasOneUse() && VT.isInteger() && !VT.isVector()) {
3765 SDValue NewConv = DAG.getNode(ISD::BIT_CONVERT, N0.getDebugLoc(), VT,
3767 AddToWorkList(NewConv.getNode());
3769 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
3770 if (N0.getOpcode() == ISD::FNEG)
3771 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT,
3772 NewConv, DAG.getConstant(SignBit, VT));
3773 assert(N0.getOpcode() == ISD::FABS);
3774 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
3775 NewConv, DAG.getConstant(~SignBit, VT));
3778 // fold (bitconvert (fcopysign cst, x)) ->
3779 // (or (and (bitconvert x), sign), (and cst, (not sign)))
3780 // Note that we don't handle (copysign x, cst) because this can always be
3781 // folded to an fneg or fabs.
3782 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse() &&
3783 isa<ConstantFPSDNode>(N0.getOperand(0)) &&
3784 VT.isInteger() && !VT.isVector()) {
3785 unsigned OrigXWidth = N0.getOperand(1).getValueType().getSizeInBits();
3786 MVT IntXVT = MVT::getIntegerVT(OrigXWidth);
3787 if (TLI.isTypeLegal(IntXVT) || !LegalTypes) {
3788 SDValue X = DAG.getNode(ISD::BIT_CONVERT, N0.getDebugLoc(),
3789 IntXVT, N0.getOperand(1));
3790 AddToWorkList(X.getNode());
3792 // If X has a different width than the result/lhs, sext it or truncate it.
3793 unsigned VTWidth = VT.getSizeInBits();
3794 if (OrigXWidth < VTWidth) {
3795 X = DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, X);
3796 AddToWorkList(X.getNode());
3797 } else if (OrigXWidth > VTWidth) {
3798 // To get the sign bit in the right place, we have to shift it right
3799 // before truncating.
3800 X = DAG.getNode(ISD::SRL, X.getDebugLoc(),
3801 X.getValueType(), X,
3802 DAG.getConstant(OrigXWidth-VTWidth, X.getValueType()));
3803 AddToWorkList(X.getNode());
3804 X = DAG.getNode(ISD::TRUNCATE, X.getDebugLoc(), VT, X);
3805 AddToWorkList(X.getNode());
3808 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
3809 X = DAG.getNode(ISD::AND, X.getDebugLoc(), VT,
3810 X, DAG.getConstant(SignBit, VT));
3811 AddToWorkList(X.getNode());
3813 SDValue Cst = DAG.getNode(ISD::BIT_CONVERT, N0.getDebugLoc(),
3814 VT, N0.getOperand(0));
3815 Cst = DAG.getNode(ISD::AND, Cst.getDebugLoc(), VT,
3816 Cst, DAG.getConstant(~SignBit, VT));
3817 AddToWorkList(Cst.getNode());
3819 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, X, Cst);
3823 // bitconvert(build_pair(ld, ld)) -> ld iff load locations are consecutive.
3824 if (N0.getOpcode() == ISD::BUILD_PAIR) {
3825 SDValue CombineLD = CombineConsecutiveLoads(N0.getNode(), VT);
3826 if (CombineLD.getNode())
3833 SDValue DAGCombiner::visitBUILD_PAIR(SDNode *N) {
3834 MVT VT = N->getValueType(0);
3835 return CombineConsecutiveLoads(N, VT);
3838 /// ConstantFoldBIT_CONVERTofBUILD_VECTOR - We know that BV is a build_vector
3839 /// node with Constant, ConstantFP or Undef operands. DstEltVT indicates the
3840 /// destination element value type.
3841 SDValue DAGCombiner::
3842 ConstantFoldBIT_CONVERTofBUILD_VECTOR(SDNode *BV, MVT DstEltVT) {
3843 MVT SrcEltVT = BV->getOperand(0).getValueType();
3845 // If this is already the right type, we're done.
3846 if (SrcEltVT == DstEltVT) return SDValue(BV, 0);
3848 unsigned SrcBitSize = SrcEltVT.getSizeInBits();
3849 unsigned DstBitSize = DstEltVT.getSizeInBits();
3851 // If this is a conversion of N elements of one type to N elements of another
3852 // type, convert each element. This handles FP<->INT cases.
3853 if (SrcBitSize == DstBitSize) {
3854 SmallVector<SDValue, 8> Ops;
3855 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
3856 Ops.push_back(DAG.getNode(ISD::BIT_CONVERT, BV->getDebugLoc(),
3857 DstEltVT, BV->getOperand(i)));
3858 AddToWorkList(Ops.back().getNode());
3860 MVT VT = MVT::getVectorVT(DstEltVT,
3861 BV->getValueType(0).getVectorNumElements());
3862 return DAG.getNode(ISD::BUILD_VECTOR, BV->getDebugLoc(), VT,
3863 &Ops[0], Ops.size());
3866 // Otherwise, we're growing or shrinking the elements. To avoid having to
3867 // handle annoying details of growing/shrinking FP values, we convert them to
3869 if (SrcEltVT.isFloatingPoint()) {
3870 // Convert the input float vector to a int vector where the elements are the
3872 assert((SrcEltVT == MVT::f32 || SrcEltVT == MVT::f64) && "Unknown FP VT!");
3873 MVT IntVT = MVT::getIntegerVT(SrcEltVT.getSizeInBits());
3874 BV = ConstantFoldBIT_CONVERTofBUILD_VECTOR(BV, IntVT).getNode();
3878 // Now we know the input is an integer vector. If the output is a FP type,
3879 // convert to integer first, then to FP of the right size.
3880 if (DstEltVT.isFloatingPoint()) {
3881 assert((DstEltVT == MVT::f32 || DstEltVT == MVT::f64) && "Unknown FP VT!");
3882 MVT TmpVT = MVT::getIntegerVT(DstEltVT.getSizeInBits());
3883 SDNode *Tmp = ConstantFoldBIT_CONVERTofBUILD_VECTOR(BV, TmpVT).getNode();
3885 // Next, convert to FP elements of the same size.
3886 return ConstantFoldBIT_CONVERTofBUILD_VECTOR(Tmp, DstEltVT);
3889 // Okay, we know the src/dst types are both integers of differing types.
3890 // Handling growing first.
3891 assert(SrcEltVT.isInteger() && DstEltVT.isInteger());
3892 if (SrcBitSize < DstBitSize) {
3893 unsigned NumInputsPerOutput = DstBitSize/SrcBitSize;
3895 SmallVector<SDValue, 8> Ops;
3896 for (unsigned i = 0, e = BV->getNumOperands(); i != e;
3897 i += NumInputsPerOutput) {
3898 bool isLE = TLI.isLittleEndian();
3899 APInt NewBits = APInt(DstBitSize, 0);
3900 bool EltIsUndef = true;
3901 for (unsigned j = 0; j != NumInputsPerOutput; ++j) {
3902 // Shift the previously computed bits over.
3903 NewBits <<= SrcBitSize;
3904 SDValue Op = BV->getOperand(i+ (isLE ? (NumInputsPerOutput-j-1) : j));
3905 if (Op.getOpcode() == ISD::UNDEF) continue;
3909 APInt(cast<ConstantSDNode>(Op)->getAPIntValue()).zext(DstBitSize);
3913 Ops.push_back(DAG.getUNDEF(DstEltVT));
3915 Ops.push_back(DAG.getConstant(NewBits, DstEltVT));
3918 MVT VT = MVT::getVectorVT(DstEltVT, Ops.size());
3919 return DAG.getNode(ISD::BUILD_VECTOR, BV->getDebugLoc(), VT,
3920 &Ops[0], Ops.size());
3923 // Finally, this must be the case where we are shrinking elements: each input
3924 // turns into multiple outputs.
3925 bool isS2V = ISD::isScalarToVector(BV);
3926 unsigned NumOutputsPerInput = SrcBitSize/DstBitSize;
3927 MVT VT = MVT::getVectorVT(DstEltVT, NumOutputsPerInput*BV->getNumOperands());
3928 SmallVector<SDValue, 8> Ops;
3930 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
3931 if (BV->getOperand(i).getOpcode() == ISD::UNDEF) {
3932 for (unsigned j = 0; j != NumOutputsPerInput; ++j)
3933 Ops.push_back(DAG.getUNDEF(DstEltVT));
3937 APInt OpVal = cast<ConstantSDNode>(BV->getOperand(i))->getAPIntValue();
3939 for (unsigned j = 0; j != NumOutputsPerInput; ++j) {
3940 APInt ThisVal = APInt(OpVal).trunc(DstBitSize);
3941 Ops.push_back(DAG.getConstant(ThisVal, DstEltVT));
3942 if (isS2V && i == 0 && j == 0 && APInt(ThisVal).zext(SrcBitSize) == OpVal)
3943 // Simply turn this into a SCALAR_TO_VECTOR of the new type.
3944 return DAG.getNode(ISD::SCALAR_TO_VECTOR, BV->getDebugLoc(), VT,
3946 OpVal = OpVal.lshr(DstBitSize);
3949 // For big endian targets, swap the order of the pieces of each element.
3950 if (TLI.isBigEndian())
3951 std::reverse(Ops.end()-NumOutputsPerInput, Ops.end());
3954 return DAG.getNode(ISD::BUILD_VECTOR, BV->getDebugLoc(), VT,
3955 &Ops[0], Ops.size());
3958 SDValue DAGCombiner::visitFADD(SDNode *N) {
3959 SDValue N0 = N->getOperand(0);
3960 SDValue N1 = N->getOperand(1);
3961 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3962 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
3963 MVT VT = N->getValueType(0);
3966 if (VT.isVector()) {
3967 SDValue FoldedVOp = SimplifyVBinOp(N);
3968 if (FoldedVOp.getNode()) return FoldedVOp;
3971 // fold (fadd c1, c2) -> (fadd c1, c2)
3972 if (N0CFP && N1CFP && VT != MVT::ppcf128)
3973 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0, N1);
3974 // canonicalize constant to RHS
3975 if (N0CFP && !N1CFP)
3976 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N1, N0);
3977 // fold (fadd A, 0) -> A
3978 if (UnsafeFPMath && N1CFP && N1CFP->getValueAPF().isZero())
3980 // fold (fadd A, (fneg B)) -> (fsub A, B)
3981 if (isNegatibleForFree(N1, LegalOperations) == 2)
3982 return DAG.getNode(ISD::FSUB, N->getDebugLoc(), VT, N0,
3983 GetNegatedExpression(N1, DAG, LegalOperations));
3984 // fold (fadd (fneg A), B) -> (fsub B, A)
3985 if (isNegatibleForFree(N0, LegalOperations) == 2)
3986 return DAG.getNode(ISD::FSUB, N->getDebugLoc(), VT, N1,
3987 GetNegatedExpression(N0, DAG, LegalOperations));
3989 // If allowed, fold (fadd (fadd x, c1), c2) -> (fadd x, (fadd c1, c2))
3990 if (UnsafeFPMath && N1CFP && N0.getOpcode() == ISD::FADD &&
3991 N0.getNode()->hasOneUse() && isa<ConstantFPSDNode>(N0.getOperand(1)))
3992 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0.getOperand(0),
3993 DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
3994 N0.getOperand(1), N1));
3999 SDValue DAGCombiner::visitFSUB(SDNode *N) {
4000 SDValue N0 = N->getOperand(0);
4001 SDValue N1 = N->getOperand(1);
4002 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
4003 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
4004 MVT VT = N->getValueType(0);
4007 if (VT.isVector()) {
4008 SDValue FoldedVOp = SimplifyVBinOp(N);
4009 if (FoldedVOp.getNode()) return FoldedVOp;
4012 // fold (fsub c1, c2) -> c1-c2
4013 if (N0CFP && N1CFP && VT != MVT::ppcf128)
4014 return DAG.getNode(ISD::FSUB, N->getDebugLoc(), VT, N0, N1);
4015 // fold (fsub A, 0) -> A
4016 if (UnsafeFPMath && N1CFP && N1CFP->getValueAPF().isZero())
4018 // fold (fsub 0, B) -> -B
4019 if (UnsafeFPMath && N0CFP && N0CFP->getValueAPF().isZero()) {
4020 if (isNegatibleForFree(N1, LegalOperations))
4021 return GetNegatedExpression(N1, DAG, LegalOperations);
4022 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
4023 return DAG.getNode(ISD::FNEG, N->getDebugLoc(), VT, N1);
4025 // fold (fsub A, (fneg B)) -> (fadd A, B)
4026 if (isNegatibleForFree(N1, LegalOperations))
4027 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0,
4028 GetNegatedExpression(N1, DAG, LegalOperations));
4033 SDValue DAGCombiner::visitFMUL(SDNode *N) {
4034 SDValue N0 = N->getOperand(0);
4035 SDValue N1 = N->getOperand(1);
4036 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
4037 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
4038 MVT VT = N->getValueType(0);
4041 if (VT.isVector()) {
4042 SDValue FoldedVOp = SimplifyVBinOp(N);
4043 if (FoldedVOp.getNode()) return FoldedVOp;
4046 // fold (fmul c1, c2) -> c1*c2
4047 if (N0CFP && N1CFP && VT != MVT::ppcf128)
4048 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT, N0, N1);
4049 // canonicalize constant to RHS
4050 if (N0CFP && !N1CFP)
4051 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT, N1, N0);
4052 // fold (fmul A, 0) -> 0
4053 if (UnsafeFPMath && N1CFP && N1CFP->getValueAPF().isZero())
4055 // fold (fmul X, 2.0) -> (fadd X, X)
4056 if (N1CFP && N1CFP->isExactlyValue(+2.0))
4057 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0, N0);
4058 // fold (fmul X, (fneg 1.0)) -> (fneg X)
4059 if (N1CFP && N1CFP->isExactlyValue(-1.0))
4060 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
4061 return DAG.getNode(ISD::FNEG, N->getDebugLoc(), VT, N0);
4063 // fold (fmul (fneg X), (fneg Y)) -> (fmul X, Y)
4064 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations)) {
4065 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations)) {
4066 // Both can be negated for free, check to see if at least one is cheaper
4068 if (LHSNeg == 2 || RHSNeg == 2)
4069 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
4070 GetNegatedExpression(N0, DAG, LegalOperations),
4071 GetNegatedExpression(N1, DAG, LegalOperations));
4075 // If allowed, fold (fmul (fmul x, c1), c2) -> (fmul x, (fmul c1, c2))
4076 if (UnsafeFPMath && N1CFP && N0.getOpcode() == ISD::FMUL &&
4077 N0.getNode()->hasOneUse() && isa<ConstantFPSDNode>(N0.getOperand(1)))
4078 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT, N0.getOperand(0),
4079 DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
4080 N0.getOperand(1), N1));
4085 SDValue DAGCombiner::visitFDIV(SDNode *N) {
4086 SDValue N0 = N->getOperand(0);
4087 SDValue N1 = N->getOperand(1);
4088 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
4089 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
4090 MVT VT = N->getValueType(0);
4093 if (VT.isVector()) {
4094 SDValue FoldedVOp = SimplifyVBinOp(N);
4095 if (FoldedVOp.getNode()) return FoldedVOp;
4098 // fold (fdiv c1, c2) -> c1/c2
4099 if (N0CFP && N1CFP && VT != MVT::ppcf128)
4100 return DAG.getNode(ISD::FDIV, N->getDebugLoc(), VT, N0, N1);
4103 // (fdiv (fneg X), (fneg Y)) -> (fdiv X, Y)
4104 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations)) {
4105 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations)) {
4106 // Both can be negated for free, check to see if at least one is cheaper
4108 if (LHSNeg == 2 || RHSNeg == 2)
4109 return DAG.getNode(ISD::FDIV, N->getDebugLoc(), VT,
4110 GetNegatedExpression(N0, DAG, LegalOperations),
4111 GetNegatedExpression(N1, DAG, LegalOperations));
4118 SDValue DAGCombiner::visitFREM(SDNode *N) {
4119 SDValue N0 = N->getOperand(0);
4120 SDValue N1 = N->getOperand(1);
4121 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
4122 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
4123 MVT VT = N->getValueType(0);
4125 // fold (frem c1, c2) -> fmod(c1,c2)
4126 if (N0CFP && N1CFP && VT != MVT::ppcf128)
4127 return DAG.getNode(ISD::FREM, N->getDebugLoc(), VT, N0, N1);
4132 SDValue DAGCombiner::visitFCOPYSIGN(SDNode *N) {
4133 SDValue N0 = N->getOperand(0);
4134 SDValue N1 = N->getOperand(1);
4135 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
4136 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
4137 MVT VT = N->getValueType(0);
4139 if (N0CFP && N1CFP && VT != MVT::ppcf128) // Constant fold
4140 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT, N0, N1);
4143 const APFloat& V = N1CFP->getValueAPF();
4144 // copysign(x, c1) -> fabs(x) iff ispos(c1)
4145 // copysign(x, c1) -> fneg(fabs(x)) iff isneg(c1)
4146 if (!V.isNegative()) {
4147 if (!LegalOperations || TLI.isOperationLegal(ISD::FABS, VT))
4148 return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0);
4150 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
4151 return DAG.getNode(ISD::FNEG, N->getDebugLoc(), VT,
4152 DAG.getNode(ISD::FABS, N0.getDebugLoc(), VT, N0));
4156 // copysign(fabs(x), y) -> copysign(x, y)
4157 // copysign(fneg(x), y) -> copysign(x, y)
4158 // copysign(copysign(x,z), y) -> copysign(x, y)
4159 if (N0.getOpcode() == ISD::FABS || N0.getOpcode() == ISD::FNEG ||
4160 N0.getOpcode() == ISD::FCOPYSIGN)
4161 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT,
4162 N0.getOperand(0), N1);
4164 // copysign(x, abs(y)) -> abs(x)
4165 if (N1.getOpcode() == ISD::FABS)
4166 return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0);
4168 // copysign(x, copysign(y,z)) -> copysign(x, z)
4169 if (N1.getOpcode() == ISD::FCOPYSIGN)
4170 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT,
4171 N0, N1.getOperand(1));
4173 // copysign(x, fp_extend(y)) -> copysign(x, y)
4174 // copysign(x, fp_round(y)) -> copysign(x, y)
4175 if (N1.getOpcode() == ISD::FP_EXTEND || N1.getOpcode() == ISD::FP_ROUND)
4176 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT,
4177 N0, N1.getOperand(0));
4182 SDValue DAGCombiner::visitSINT_TO_FP(SDNode *N) {
4183 SDValue N0 = N->getOperand(0);
4184 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
4185 MVT VT = N->getValueType(0);
4186 MVT OpVT = N0.getValueType();
4188 // fold (sint_to_fp c1) -> c1fp
4189 if (N0C && OpVT != MVT::ppcf128)
4190 return DAG.getNode(ISD::SINT_TO_FP, N->getDebugLoc(), VT, N0);
4192 // If the input is a legal type, and SINT_TO_FP is not legal on this target,
4193 // but UINT_TO_FP is legal on this target, try to convert.
4194 if (!TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT) &&
4195 TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT)) {
4196 // If the sign bit is known to be zero, we can change this to UINT_TO_FP.
4197 if (DAG.SignBitIsZero(N0))
4198 return DAG.getNode(ISD::UINT_TO_FP, N->getDebugLoc(), VT, N0);
4204 SDValue DAGCombiner::visitUINT_TO_FP(SDNode *N) {
4205 SDValue N0 = N->getOperand(0);
4206 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
4207 MVT VT = N->getValueType(0);
4208 MVT OpVT = N0.getValueType();
4210 // fold (uint_to_fp c1) -> c1fp
4211 if (N0C && OpVT != MVT::ppcf128)
4212 return DAG.getNode(ISD::UINT_TO_FP, N->getDebugLoc(), VT, N0);
4214 // If the input is a legal type, and UINT_TO_FP is not legal on this target,
4215 // but SINT_TO_FP is legal on this target, try to convert.
4216 if (!TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT) &&
4217 TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT)) {
4218 // If the sign bit is known to be zero, we can change this to SINT_TO_FP.
4219 if (DAG.SignBitIsZero(N0))
4220 return DAG.getNode(ISD::SINT_TO_FP, N->getDebugLoc(), VT, N0);
4226 SDValue DAGCombiner::visitFP_TO_SINT(SDNode *N) {
4227 SDValue N0 = N->getOperand(0);
4228 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
4229 MVT VT = N->getValueType(0);
4231 // fold (fp_to_sint c1fp) -> c1
4233 return DAG.getNode(ISD::FP_TO_SINT, N->getDebugLoc(), VT, N0);
4238 SDValue DAGCombiner::visitFP_TO_UINT(SDNode *N) {
4239 SDValue N0 = N->getOperand(0);
4240 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
4241 MVT VT = N->getValueType(0);
4243 // fold (fp_to_uint c1fp) -> c1
4244 if (N0CFP && VT != MVT::ppcf128)
4245 return DAG.getNode(ISD::FP_TO_UINT, N->getDebugLoc(), VT, N0);
4250 SDValue DAGCombiner::visitFP_ROUND(SDNode *N) {
4251 SDValue N0 = N->getOperand(0);
4252 SDValue N1 = N->getOperand(1);
4253 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
4254 MVT VT = N->getValueType(0);
4256 // fold (fp_round c1fp) -> c1fp
4257 if (N0CFP && N0.getValueType() != MVT::ppcf128)
4258 return DAG.getNode(ISD::FP_ROUND, N->getDebugLoc(), VT, N0, N1);
4260 // fold (fp_round (fp_extend x)) -> x
4261 if (N0.getOpcode() == ISD::FP_EXTEND && VT == N0.getOperand(0).getValueType())
4262 return N0.getOperand(0);
4264 // fold (fp_round (fp_round x)) -> (fp_round x)
4265 if (N0.getOpcode() == ISD::FP_ROUND) {
4266 // This is a value preserving truncation if both round's are.
4267 bool IsTrunc = N->getConstantOperandVal(1) == 1 &&
4268 N0.getNode()->getConstantOperandVal(1) == 1;
4269 return DAG.getNode(ISD::FP_ROUND, N->getDebugLoc(), VT, N0.getOperand(0),
4270 DAG.getIntPtrConstant(IsTrunc));
4273 // fold (fp_round (copysign X, Y)) -> (copysign (fp_round X), Y)
4274 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse()) {
4275 SDValue Tmp = DAG.getNode(ISD::FP_ROUND, N0.getDebugLoc(), VT,
4276 N0.getOperand(0), N1);
4277 AddToWorkList(Tmp.getNode());
4278 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT,
4279 Tmp, N0.getOperand(1));
4285 SDValue DAGCombiner::visitFP_ROUND_INREG(SDNode *N) {
4286 SDValue N0 = N->getOperand(0);
4287 MVT VT = N->getValueType(0);
4288 MVT EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
4289 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
4291 // fold (fp_round_inreg c1fp) -> c1fp
4292 if (N0CFP && (TLI.isTypeLegal(EVT) || !LegalTypes)) {
4293 SDValue Round = DAG.getConstantFP(*N0CFP->getConstantFPValue(), EVT);
4294 return DAG.getNode(ISD::FP_EXTEND, N->getDebugLoc(), VT, Round);
4300 SDValue DAGCombiner::visitFP_EXTEND(SDNode *N) {
4301 SDValue N0 = N->getOperand(0);
4302 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
4303 MVT VT = N->getValueType(0);
4305 // If this is fp_round(fpextend), don't fold it, allow ourselves to be folded.
4306 if (N->hasOneUse() &&
4307 N->use_begin()->getOpcode() == ISD::FP_ROUND)
4310 // fold (fp_extend c1fp) -> c1fp
4311 if (N0CFP && VT != MVT::ppcf128)
4312 return DAG.getNode(ISD::FP_EXTEND, N->getDebugLoc(), VT, N0);
4314 // Turn fp_extend(fp_round(X, 1)) -> x since the fp_round doesn't affect the
4316 if (N0.getOpcode() == ISD::FP_ROUND
4317 && N0.getNode()->getConstantOperandVal(1) == 1) {
4318 SDValue In = N0.getOperand(0);
4319 if (In.getValueType() == VT) return In;
4320 if (VT.bitsLT(In.getValueType()))
4321 return DAG.getNode(ISD::FP_ROUND, N->getDebugLoc(), VT,
4322 In, N0.getOperand(1));
4323 return DAG.getNode(ISD::FP_EXTEND, N->getDebugLoc(), VT, In);
4326 // fold (fpext (load x)) -> (fpext (fptrunc (extload x)))
4327 if (ISD::isNON_EXTLoad(N0.getNode()) && N0.hasOneUse() &&
4328 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
4329 TLI.isLoadExtLegal(ISD::EXTLOAD, N0.getValueType()))) {
4330 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4331 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, N->getDebugLoc(), VT,
4333 LN0->getBasePtr(), LN0->getSrcValue(),
4334 LN0->getSrcValueOffset(),
4336 LN0->isVolatile(), LN0->getAlignment());
4337 CombineTo(N, ExtLoad);
4338 CombineTo(N0.getNode(),
4339 DAG.getNode(ISD::FP_ROUND, N0.getDebugLoc(),
4340 N0.getValueType(), ExtLoad, DAG.getIntPtrConstant(1)),
4341 ExtLoad.getValue(1));
4342 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4348 SDValue DAGCombiner::visitFNEG(SDNode *N) {
4349 SDValue N0 = N->getOperand(0);
4351 if (isNegatibleForFree(N0, LegalOperations))
4352 return GetNegatedExpression(N0, DAG, LegalOperations);
4354 // Transform fneg(bitconvert(x)) -> bitconvert(x^sign) to avoid loading
4355 // constant pool values.
4356 if (N0.getOpcode() == ISD::BIT_CONVERT && N0.getNode()->hasOneUse() &&
4357 N0.getOperand(0).getValueType().isInteger() &&
4358 !N0.getOperand(0).getValueType().isVector()) {
4359 SDValue Int = N0.getOperand(0);
4360 MVT IntVT = Int.getValueType();
4361 if (IntVT.isInteger() && !IntVT.isVector()) {
4362 Int = DAG.getNode(ISD::XOR, N0.getDebugLoc(), IntVT, Int,
4363 DAG.getConstant(APInt::getSignBit(IntVT.getSizeInBits()), IntVT));
4364 AddToWorkList(Int.getNode());
4365 return DAG.getNode(ISD::BIT_CONVERT, N->getDebugLoc(),
4366 N->getValueType(0), Int);
4373 SDValue DAGCombiner::visitFABS(SDNode *N) {
4374 SDValue N0 = N->getOperand(0);
4375 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
4376 MVT VT = N->getValueType(0);
4378 // fold (fabs c1) -> fabs(c1)
4379 if (N0CFP && VT != MVT::ppcf128)
4380 return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0);
4381 // fold (fabs (fabs x)) -> (fabs x)
4382 if (N0.getOpcode() == ISD::FABS)
4383 return N->getOperand(0);
4384 // fold (fabs (fneg x)) -> (fabs x)
4385 // fold (fabs (fcopysign x, y)) -> (fabs x)
4386 if (N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FCOPYSIGN)
4387 return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0.getOperand(0));
4389 // Transform fabs(bitconvert(x)) -> bitconvert(x&~sign) to avoid loading
4390 // constant pool values.
4391 if (N0.getOpcode() == ISD::BIT_CONVERT && N0.getNode()->hasOneUse() &&
4392 N0.getOperand(0).getValueType().isInteger() &&
4393 !N0.getOperand(0).getValueType().isVector()) {
4394 SDValue Int = N0.getOperand(0);
4395 MVT IntVT = Int.getValueType();
4396 if (IntVT.isInteger() && !IntVT.isVector()) {
4397 Int = DAG.getNode(ISD::AND, N0.getDebugLoc(), IntVT, Int,
4398 DAG.getConstant(~APInt::getSignBit(IntVT.getSizeInBits()), IntVT));
4399 AddToWorkList(Int.getNode());
4400 return DAG.getNode(ISD::BIT_CONVERT, N->getDebugLoc(),
4401 N->getValueType(0), Int);
4408 SDValue DAGCombiner::visitBRCOND(SDNode *N) {
4409 SDValue Chain = N->getOperand(0);
4410 SDValue N1 = N->getOperand(1);
4411 SDValue N2 = N->getOperand(2);
4412 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
4414 // never taken branch, fold to chain
4415 if (N1C && N1C->isNullValue())
4417 // unconditional branch
4418 if (N1C && N1C->getAPIntValue() == 1)
4419 return DAG.getNode(ISD::BR, N->getDebugLoc(), MVT::Other, Chain, N2);
4420 // fold a brcond with a setcc condition into a BR_CC node if BR_CC is legal
4422 if (N1.getOpcode() == ISD::SETCC &&
4423 TLI.isOperationLegalOrCustom(ISD::BR_CC, MVT::Other)) {
4424 return DAG.getNode(ISD::BR_CC, N->getDebugLoc(), MVT::Other,
4425 Chain, N1.getOperand(2),
4426 N1.getOperand(0), N1.getOperand(1), N2);
4432 // Operand List for BR_CC: Chain, CondCC, CondLHS, CondRHS, DestBB.
4434 SDValue DAGCombiner::visitBR_CC(SDNode *N) {
4435 CondCodeSDNode *CC = cast<CondCodeSDNode>(N->getOperand(1));
4436 SDValue CondLHS = N->getOperand(2), CondRHS = N->getOperand(3);
4438 // Use SimplifySetCC to simplify SETCC's.
4439 SDValue Simp = SimplifySetCC(TLI.getSetCCResultType(CondLHS.getValueType()),
4440 CondLHS, CondRHS, CC->get(), N->getDebugLoc(),
4442 if (Simp.getNode()) AddToWorkList(Simp.getNode());
4444 ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(Simp.getNode());
4446 // fold br_cc true, dest -> br dest (unconditional branch)
4447 if (SCCC && !SCCC->isNullValue())
4448 return DAG.getNode(ISD::BR, N->getDebugLoc(), MVT::Other,
4449 N->getOperand(0), N->getOperand(4));
4450 // fold br_cc false, dest -> unconditional fall through
4451 if (SCCC && SCCC->isNullValue())
4452 return N->getOperand(0);
4454 // fold to a simpler setcc
4455 if (Simp.getNode() && Simp.getOpcode() == ISD::SETCC)
4456 return DAG.getNode(ISD::BR_CC, N->getDebugLoc(), MVT::Other,
4457 N->getOperand(0), Simp.getOperand(2),
4458 Simp.getOperand(0), Simp.getOperand(1),
4464 /// CombineToPreIndexedLoadStore - Try turning a load / store into a
4465 /// pre-indexed load / store when the base pointer is an add or subtract
4466 /// and it has other uses besides the load / store. After the
4467 /// transformation, the new indexed load / store has effectively folded
4468 /// the add / subtract in and all of its other uses are redirected to the
4469 /// new load / store.
4470 bool DAGCombiner::CombineToPreIndexedLoadStore(SDNode *N) {
4471 if (!LegalOperations)
4477 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
4478 if (LD->isIndexed())
4480 VT = LD->getMemoryVT();
4481 if (!TLI.isIndexedLoadLegal(ISD::PRE_INC, VT) &&
4482 !TLI.isIndexedLoadLegal(ISD::PRE_DEC, VT))
4484 Ptr = LD->getBasePtr();
4485 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
4486 if (ST->isIndexed())
4488 VT = ST->getMemoryVT();
4489 if (!TLI.isIndexedStoreLegal(ISD::PRE_INC, VT) &&
4490 !TLI.isIndexedStoreLegal(ISD::PRE_DEC, VT))
4492 Ptr = ST->getBasePtr();
4498 // If the pointer is not an add/sub, or if it doesn't have multiple uses, bail
4499 // out. There is no reason to make this a preinc/predec.
4500 if ((Ptr.getOpcode() != ISD::ADD && Ptr.getOpcode() != ISD::SUB) ||
4501 Ptr.getNode()->hasOneUse())
4504 // Ask the target to do addressing mode selection.
4507 ISD::MemIndexedMode AM = ISD::UNINDEXED;
4508 if (!TLI.getPreIndexedAddressParts(N, BasePtr, Offset, AM, DAG))
4510 // Don't create a indexed load / store with zero offset.
4511 if (isa<ConstantSDNode>(Offset) &&
4512 cast<ConstantSDNode>(Offset)->isNullValue())
4515 // Try turning it into a pre-indexed load / store except when:
4516 // 1) The new base ptr is a frame index.
4517 // 2) If N is a store and the new base ptr is either the same as or is a
4518 // predecessor of the value being stored.
4519 // 3) Another use of old base ptr is a predecessor of N. If ptr is folded
4520 // that would create a cycle.
4521 // 4) All uses are load / store ops that use it as old base ptr.
4523 // Check #1. Preinc'ing a frame index would require copying the stack pointer
4524 // (plus the implicit offset) to a register to preinc anyway.
4525 if (isa<FrameIndexSDNode>(BasePtr))
4530 SDValue Val = cast<StoreSDNode>(N)->getValue();
4531 if (Val == BasePtr || BasePtr.getNode()->isPredecessorOf(Val.getNode()))
4535 // Now check for #3 and #4.
4536 bool RealUse = false;
4537 for (SDNode::use_iterator I = Ptr.getNode()->use_begin(),
4538 E = Ptr.getNode()->use_end(); I != E; ++I) {
4542 if (Use->isPredecessorOf(N))
4545 if (!((Use->getOpcode() == ISD::LOAD &&
4546 cast<LoadSDNode>(Use)->getBasePtr() == Ptr) ||
4547 (Use->getOpcode() == ISD::STORE &&
4548 cast<StoreSDNode>(Use)->getBasePtr() == Ptr)))
4557 Result = DAG.getIndexedLoad(SDValue(N,0), N->getDebugLoc(),
4558 BasePtr, Offset, AM);
4560 Result = DAG.getIndexedStore(SDValue(N,0), N->getDebugLoc(),
4561 BasePtr, Offset, AM);
4564 DOUT << "\nReplacing.4 "; DEBUG(N->dump(&DAG));
4565 DOUT << "\nWith: "; DEBUG(Result.getNode()->dump(&DAG));
4567 WorkListRemover DeadNodes(*this);
4569 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0),
4571 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2),
4574 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1),
4578 // Finally, since the node is now dead, remove it from the graph.
4581 // Replace the uses of Ptr with uses of the updated base value.
4582 DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0),
4584 removeFromWorkList(Ptr.getNode());
4585 DAG.DeleteNode(Ptr.getNode());
4590 /// CombineToPostIndexedLoadStore - Try to combine a load / store with a
4591 /// add / sub of the base pointer node into a post-indexed load / store.
4592 /// The transformation folded the add / subtract into the new indexed
4593 /// load / store effectively and all of its uses are redirected to the
4594 /// new load / store.
4595 bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
4596 if (!LegalOperations)
4602 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
4603 if (LD->isIndexed())
4605 VT = LD->getMemoryVT();
4606 if (!TLI.isIndexedLoadLegal(ISD::POST_INC, VT) &&
4607 !TLI.isIndexedLoadLegal(ISD::POST_DEC, VT))
4609 Ptr = LD->getBasePtr();
4610 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
4611 if (ST->isIndexed())
4613 VT = ST->getMemoryVT();
4614 if (!TLI.isIndexedStoreLegal(ISD::POST_INC, VT) &&
4615 !TLI.isIndexedStoreLegal(ISD::POST_DEC, VT))
4617 Ptr = ST->getBasePtr();
4623 if (Ptr.getNode()->hasOneUse())
4626 for (SDNode::use_iterator I = Ptr.getNode()->use_begin(),
4627 E = Ptr.getNode()->use_end(); I != E; ++I) {
4630 (Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB))
4635 ISD::MemIndexedMode AM = ISD::UNINDEXED;
4636 if (TLI.getPostIndexedAddressParts(N, Op, BasePtr, Offset, AM, DAG)) {
4638 std::swap(BasePtr, Offset);
4641 // Don't create a indexed load / store with zero offset.
4642 if (isa<ConstantSDNode>(Offset) &&
4643 cast<ConstantSDNode>(Offset)->isNullValue())
4646 // Try turning it into a post-indexed load / store except when
4647 // 1) All uses are load / store ops that use it as base ptr.
4648 // 2) Op must be independent of N, i.e. Op is neither a predecessor
4649 // nor a successor of N. Otherwise, if Op is folded that would
4653 bool TryNext = false;
4654 for (SDNode::use_iterator II = BasePtr.getNode()->use_begin(),
4655 EE = BasePtr.getNode()->use_end(); II != EE; ++II) {
4657 if (Use == Ptr.getNode())
4660 // If all the uses are load / store addresses, then don't do the
4662 if (Use->getOpcode() == ISD::ADD || Use->getOpcode() == ISD::SUB){
4663 bool RealUse = false;
4664 for (SDNode::use_iterator III = Use->use_begin(),
4665 EEE = Use->use_end(); III != EEE; ++III) {
4666 SDNode *UseUse = *III;
4667 if (!((UseUse->getOpcode() == ISD::LOAD &&
4668 cast<LoadSDNode>(UseUse)->getBasePtr().getNode() == Use) ||
4669 (UseUse->getOpcode() == ISD::STORE &&
4670 cast<StoreSDNode>(UseUse)->getBasePtr().getNode() == Use)))
4685 if (!Op->isPredecessorOf(N) && !N->isPredecessorOf(Op)) {
4686 SDValue Result = isLoad
4687 ? DAG.getIndexedLoad(SDValue(N,0), N->getDebugLoc(),
4688 BasePtr, Offset, AM)
4689 : DAG.getIndexedStore(SDValue(N,0), N->getDebugLoc(),
4690 BasePtr, Offset, AM);
4693 DOUT << "\nReplacing.5 "; DEBUG(N->dump(&DAG));
4694 DOUT << "\nWith: "; DEBUG(Result.getNode()->dump(&DAG));
4696 WorkListRemover DeadNodes(*this);
4698 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0),
4700 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2),
4703 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1),
4707 // Finally, since the node is now dead, remove it from the graph.
4710 // Replace the uses of Use with uses of the updated base value.
4711 DAG.ReplaceAllUsesOfValueWith(SDValue(Op, 0),
4712 Result.getValue(isLoad ? 1 : 0),
4714 removeFromWorkList(Op);
4724 /// InferAlignment - If we can infer some alignment information from this
4725 /// pointer, return it.
4726 static unsigned InferAlignment(SDValue Ptr, SelectionDAG &DAG) {
4727 // If this is a direct reference to a stack slot, use information about the
4728 // stack slot's alignment.
4729 int FrameIdx = 1 << 31;
4730 int64_t FrameOffset = 0;
4731 if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Ptr)) {
4732 FrameIdx = FI->getIndex();
4733 } else if (Ptr.getOpcode() == ISD::ADD &&
4734 isa<ConstantSDNode>(Ptr.getOperand(1)) &&
4735 isa<FrameIndexSDNode>(Ptr.getOperand(0))) {
4736 FrameIdx = cast<FrameIndexSDNode>(Ptr.getOperand(0))->getIndex();
4737 FrameOffset = Ptr.getConstantOperandVal(1);
4740 if (FrameIdx != (1 << 31)) {
4741 // FIXME: Handle FI+CST.
4742 const MachineFrameInfo &MFI = *DAG.getMachineFunction().getFrameInfo();
4743 if (MFI.isFixedObjectIndex(FrameIdx)) {
4744 int64_t ObjectOffset = MFI.getObjectOffset(FrameIdx) + FrameOffset;
4746 // The alignment of the frame index can be determined from its offset from
4747 // the incoming frame position. If the frame object is at offset 32 and
4748 // the stack is guaranteed to be 16-byte aligned, then we know that the
4749 // object is 16-byte aligned.
4750 unsigned StackAlign = DAG.getTarget().getFrameInfo()->getStackAlignment();
4751 unsigned Align = MinAlign(ObjectOffset, StackAlign);
4753 // Finally, the frame object itself may have a known alignment. Factor
4754 // the alignment + offset into a new alignment. For example, if we know
4755 // the FI is 8 byte aligned, but the pointer is 4 off, we really have a
4756 // 4-byte alignment of the resultant pointer. Likewise align 4 + 4-byte
4757 // offset = 4-byte alignment, align 4 + 1-byte offset = align 1, etc.
4758 unsigned FIInfoAlign = MinAlign(MFI.getObjectAlignment(FrameIdx),
4760 return std::max(Align, FIInfoAlign);
4767 SDValue DAGCombiner::visitLOAD(SDNode *N) {
4768 LoadSDNode *LD = cast<LoadSDNode>(N);
4769 SDValue Chain = LD->getChain();
4770 SDValue Ptr = LD->getBasePtr();
4772 // Try to infer better alignment information than the load already has.
4773 if (!Fast && LD->isUnindexed()) {
4774 if (unsigned Align = InferAlignment(Ptr, DAG)) {
4775 if (Align > LD->getAlignment())
4776 return DAG.getExtLoad(LD->getExtensionType(), N->getDebugLoc(),
4777 LD->getValueType(0),
4778 Chain, Ptr, LD->getSrcValue(),
4779 LD->getSrcValueOffset(), LD->getMemoryVT(),
4780 LD->isVolatile(), Align);
4784 // If load is not volatile and there are no uses of the loaded value (and
4785 // the updated indexed value in case of indexed loads), change uses of the
4786 // chain value into uses of the chain input (i.e. delete the dead load).
4787 if (!LD->isVolatile()) {
4788 if (N->getValueType(1) == MVT::Other) {
4790 if (N->hasNUsesOfValue(0, 0)) {
4791 // It's not safe to use the two value CombineTo variant here. e.g.
4792 // v1, chain2 = load chain1, loc
4793 // v2, chain3 = load chain2, loc
4795 // Now we replace use of chain2 with chain1. This makes the second load
4796 // isomorphic to the one we are deleting, and thus makes this load live.
4797 DOUT << "\nReplacing.6 "; DEBUG(N->dump(&DAG));
4798 DOUT << "\nWith chain: "; DEBUG(Chain.getNode()->dump(&DAG));
4800 WorkListRemover DeadNodes(*this);
4801 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain, &DeadNodes);
4803 if (N->use_empty()) {
4804 removeFromWorkList(N);
4808 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4812 assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?");
4813 if (N->hasNUsesOfValue(0, 0) && N->hasNUsesOfValue(0, 1)) {
4814 SDValue Undef = DAG.getUNDEF(N->getValueType(0));
4815 DOUT << "\nReplacing.6 "; DEBUG(N->dump(&DAG));
4816 DOUT << "\nWith: "; DEBUG(Undef.getNode()->dump(&DAG));
4817 DOUT << " and 2 other values\n";
4818 WorkListRemover DeadNodes(*this);
4819 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Undef, &DeadNodes);
4820 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1),
4821 DAG.getUNDEF(N->getValueType(1)),
4823 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 2), Chain, &DeadNodes);
4824 removeFromWorkList(N);
4826 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4831 // If this load is directly stored, replace the load value with the stored
4833 // TODO: Handle store large -> read small portion.
4834 // TODO: Handle TRUNCSTORE/LOADEXT
4835 if (LD->getExtensionType() == ISD::NON_EXTLOAD &&
4836 !LD->isVolatile()) {
4837 if (ISD::isNON_TRUNCStore(Chain.getNode())) {
4838 StoreSDNode *PrevST = cast<StoreSDNode>(Chain);
4839 if (PrevST->getBasePtr() == Ptr &&
4840 PrevST->getValue().getValueType() == N->getValueType(0))
4841 return CombineTo(N, Chain.getOperand(1), Chain);
4846 // Walk up chain skipping non-aliasing memory nodes.
4847 SDValue BetterChain = FindBetterChain(N, Chain);
4849 // If there is a better chain.
4850 if (Chain != BetterChain) {
4853 // Replace the chain to void dependency.
4854 if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
4855 ReplLoad = DAG.getLoad(N->getValueType(0), LD->getDebugLoc(),
4857 LD->getSrcValue(), LD->getSrcValueOffset(),
4858 LD->isVolatile(), LD->getAlignment());
4860 ReplLoad = DAG.getExtLoad(LD->getExtensionType(), LD->getDebugLoc(),
4861 LD->getValueType(0),
4862 BetterChain, Ptr, LD->getSrcValue(),
4863 LD->getSrcValueOffset(),
4866 LD->getAlignment());
4869 // Create token factor to keep old chain connected.
4870 SDValue Token = DAG.getNode(ISD::TokenFactor, N->getDebugLoc(),
4871 MVT::Other, Chain, ReplLoad.getValue(1));
4873 // Replace uses with load result and token factor. Don't add users
4875 return CombineTo(N, ReplLoad.getValue(0), Token, false);
4879 // Try transforming N to an indexed load.
4880 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
4881 return SDValue(N, 0);
4886 SDValue DAGCombiner::visitSTORE(SDNode *N) {
4887 StoreSDNode *ST = cast<StoreSDNode>(N);
4888 SDValue Chain = ST->getChain();
4889 SDValue Value = ST->getValue();
4890 SDValue Ptr = ST->getBasePtr();
4892 // Try to infer better alignment information than the store already has.
4893 if (!Fast && ST->isUnindexed()) {
4894 if (unsigned Align = InferAlignment(Ptr, DAG)) {
4895 if (Align > ST->getAlignment())
4896 return DAG.getTruncStore(Chain, N->getDebugLoc(), Value,
4897 Ptr, ST->getSrcValue(),
4898 ST->getSrcValueOffset(), ST->getMemoryVT(),
4899 ST->isVolatile(), Align);
4903 // If this is a store of a bit convert, store the input value if the
4904 // resultant store does not need a higher alignment than the original.
4905 if (Value.getOpcode() == ISD::BIT_CONVERT && !ST->isTruncatingStore() &&
4906 ST->isUnindexed()) {
4907 unsigned OrigAlign = ST->getAlignment();
4908 MVT SVT = Value.getOperand(0).getValueType();
4909 unsigned Align = TLI.getTargetData()->
4910 getABITypeAlignment(SVT.getTypeForMVT());
4911 if (Align <= OrigAlign &&
4912 ((!LegalOperations && !ST->isVolatile()) ||
4913 TLI.isOperationLegalOrCustom(ISD::STORE, SVT)))
4914 return DAG.getStore(Chain, N->getDebugLoc(), Value.getOperand(0),
4915 Ptr, ST->getSrcValue(),
4916 ST->getSrcValueOffset(), ST->isVolatile(), OrigAlign);
4919 // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
4920 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Value)) {
4921 // NOTE: If the original store is volatile, this transform must not increase
4922 // the number of stores. For example, on x86-32 an f64 can be stored in one
4923 // processor operation but an i64 (which is not legal) requires two. So the
4924 // transform should not be done in this case.
4925 if (Value.getOpcode() != ISD::TargetConstantFP) {
4927 switch (CFP->getValueType(0).getSimpleVT()) {
4928 default: assert(0 && "Unknown FP type");
4929 case MVT::f80: // We don't do this for these yet.
4934 if (((TLI.isTypeLegal(MVT::i32) || !LegalTypes) && !LegalOperations &&
4935 !ST->isVolatile()) ||
4936 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
4937 Tmp = DAG.getConstant((uint32_t)CFP->getValueAPF().
4938 bitcastToAPInt().getZExtValue(), MVT::i32);
4939 return DAG.getStore(Chain, N->getDebugLoc(), Tmp,
4940 Ptr, ST->getSrcValue(),
4941 ST->getSrcValueOffset(), ST->isVolatile(),
4942 ST->getAlignment());
4946 if (((TLI.isTypeLegal(MVT::i64) || !LegalTypes) && !LegalOperations &&
4947 !ST->isVolatile()) ||
4948 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i64)) {
4949 Tmp = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
4950 getZExtValue(), MVT::i64);
4951 return DAG.getStore(Chain, N->getDebugLoc(), Tmp,
4952 Ptr, ST->getSrcValue(),
4953 ST->getSrcValueOffset(), ST->isVolatile(),
4954 ST->getAlignment());
4955 } else if (!ST->isVolatile() &&
4956 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
4957 // Many FP stores are not made apparent until after legalize, e.g. for
4958 // argument passing. Since this is so common, custom legalize the
4959 // 64-bit integer store into two 32-bit stores.
4960 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
4961 SDValue Lo = DAG.getConstant(Val & 0xFFFFFFFF, MVT::i32);
4962 SDValue Hi = DAG.getConstant(Val >> 32, MVT::i32);
4963 if (TLI.isBigEndian()) std::swap(Lo, Hi);
4965 int SVOffset = ST->getSrcValueOffset();
4966 unsigned Alignment = ST->getAlignment();
4967 bool isVolatile = ST->isVolatile();
4969 SDValue St0 = DAG.getStore(Chain, ST->getDebugLoc(), Lo,
4970 Ptr, ST->getSrcValue(),
4971 ST->getSrcValueOffset(),
4972 isVolatile, ST->getAlignment());
4973 Ptr = DAG.getNode(ISD::ADD, N->getDebugLoc(), Ptr.getValueType(), Ptr,
4974 DAG.getConstant(4, Ptr.getValueType()));
4976 Alignment = MinAlign(Alignment, 4U);
4977 SDValue St1 = DAG.getStore(Chain, ST->getDebugLoc(), Hi,
4978 Ptr, ST->getSrcValue(),
4979 SVOffset, isVolatile, Alignment);
4980 return DAG.getNode(ISD::TokenFactor, N->getDebugLoc(), MVT::Other,
4990 // Walk up chain skipping non-aliasing memory nodes.
4991 SDValue BetterChain = FindBetterChain(N, Chain);
4993 // If there is a better chain.
4994 if (Chain != BetterChain) {
4995 // Replace the chain to avoid dependency.
4997 if (ST->isTruncatingStore()) {
4998 ReplStore = DAG.getTruncStore(BetterChain, N->getDebugLoc(), Value, Ptr,
4999 ST->getSrcValue(),ST->getSrcValueOffset(),
5001 ST->isVolatile(), ST->getAlignment());
5003 ReplStore = DAG.getStore(BetterChain, N->getDebugLoc(), Value, Ptr,
5004 ST->getSrcValue(), ST->getSrcValueOffset(),
5005 ST->isVolatile(), ST->getAlignment());
5008 // Create token to keep both nodes around.
5009 SDValue Token = DAG.getNode(ISD::TokenFactor, N->getDebugLoc(),
5010 MVT::Other, Chain, ReplStore);
5012 // Don't add users to work list.
5013 return CombineTo(N, Token, false);
5017 // Try transforming N to an indexed store.
5018 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
5019 return SDValue(N, 0);
5021 // FIXME: is there such a thing as a truncating indexed store?
5022 if (ST->isTruncatingStore() && ST->isUnindexed() &&
5023 Value.getValueType().isInteger()) {
5024 // See if we can simplify the input to this truncstore with knowledge that
5025 // only the low bits are being used. For example:
5026 // "truncstore (or (shl x, 8), y), i8" -> "truncstore y, i8"
5028 GetDemandedBits(Value,
5029 APInt::getLowBitsSet(Value.getValueSizeInBits(),
5030 ST->getMemoryVT().getSizeInBits()));
5031 AddToWorkList(Value.getNode());
5032 if (Shorter.getNode())
5033 return DAG.getTruncStore(Chain, N->getDebugLoc(), Shorter,
5034 Ptr, ST->getSrcValue(),
5035 ST->getSrcValueOffset(), ST->getMemoryVT(),
5036 ST->isVolatile(), ST->getAlignment());
5038 // Otherwise, see if we can simplify the operation with
5039 // SimplifyDemandedBits, which only works if the value has a single use.
5040 if (SimplifyDemandedBits(Value,
5041 APInt::getLowBitsSet(
5042 Value.getValueSizeInBits(),
5043 ST->getMemoryVT().getSizeInBits())))
5044 return SDValue(N, 0);
5047 // If this is a load followed by a store to the same location, then the store
5049 if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Value)) {
5050 if (Ld->getBasePtr() == Ptr && ST->getMemoryVT() == Ld->getMemoryVT() &&
5051 ST->isUnindexed() && !ST->isVolatile() &&
5052 // There can't be any side effects between the load and store, such as
5054 Chain.reachesChainWithoutSideEffects(SDValue(Ld, 1))) {
5055 // The store is dead, remove it.
5060 // If this is an FP_ROUND or TRUNC followed by a store, fold this into a
5061 // truncating store. We can do this even if this is already a truncstore.
5062 if ((Value.getOpcode() == ISD::FP_ROUND || Value.getOpcode() == ISD::TRUNCATE)
5063 && Value.getNode()->hasOneUse() && ST->isUnindexed() &&
5064 TLI.isTruncStoreLegal(Value.getOperand(0).getValueType(),
5065 ST->getMemoryVT())) {
5066 return DAG.getTruncStore(Chain, N->getDebugLoc(), Value.getOperand(0),
5067 Ptr, ST->getSrcValue(),
5068 ST->getSrcValueOffset(), ST->getMemoryVT(),
5069 ST->isVolatile(), ST->getAlignment());
5075 SDValue DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) {
5076 SDValue InVec = N->getOperand(0);
5077 SDValue InVal = N->getOperand(1);
5078 SDValue EltNo = N->getOperand(2);
5080 // If the invec is a BUILD_VECTOR and if EltNo is a constant, build a new
5081 // vector with the inserted element.
5082 if (InVec.getOpcode() == ISD::BUILD_VECTOR && isa<ConstantSDNode>(EltNo)) {
5083 unsigned Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
5084 SmallVector<SDValue, 8> Ops(InVec.getNode()->op_begin(),
5085 InVec.getNode()->op_end());
5086 if (Elt < Ops.size())
5088 return DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(),
5089 InVec.getValueType(), &Ops[0], Ops.size());
5095 SDValue DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) {
5096 // (vextract (scalar_to_vector val, 0) -> val
5097 SDValue InVec = N->getOperand(0);
5099 if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR)
5100 return InVec.getOperand(0);
5102 // Perform only after legalization to ensure build_vector / vector_shuffle
5103 // optimizations have already been done.
5104 if (!LegalOperations) return SDValue();
5106 // (vextract (v4f32 load $addr), c) -> (f32 load $addr+c*size)
5107 // (vextract (v4f32 s2v (f32 load $addr)), c) -> (f32 load $addr+c*size)
5108 // (vextract (v4f32 shuffle (load $addr), <1,u,u,u>), 0) -> (f32 load $addr)
5109 SDValue EltNo = N->getOperand(1);
5111 if (isa<ConstantSDNode>(EltNo)) {
5112 unsigned Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
5113 bool NewLoad = false;
5114 bool BCNumEltsChanged = false;
5115 MVT VT = InVec.getValueType();
5116 MVT EVT = VT.getVectorElementType();
5119 if (InVec.getOpcode() == ISD::BIT_CONVERT) {
5120 MVT BCVT = InVec.getOperand(0).getValueType();
5121 if (!BCVT.isVector() || EVT.bitsGT(BCVT.getVectorElementType()))
5123 if (VT.getVectorNumElements() != BCVT.getVectorNumElements())
5124 BCNumEltsChanged = true;
5125 InVec = InVec.getOperand(0);
5126 EVT = BCVT.getVectorElementType();
5130 LoadSDNode *LN0 = NULL;
5131 if (ISD::isNormalLoad(InVec.getNode())) {
5132 LN0 = cast<LoadSDNode>(InVec);
5133 } else if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR &&
5134 InVec.getOperand(0).getValueType() == EVT &&
5135 ISD::isNormalLoad(InVec.getOperand(0).getNode())) {
5136 LN0 = cast<LoadSDNode>(InVec.getOperand(0));
5137 } else if (InVec.getOpcode() == ISD::VECTOR_SHUFFLE) {
5138 // (vextract (vector_shuffle (load $addr), v2, <1, u, u, u>), 1)
5140 // (load $addr+1*size)
5142 // If the bit convert changed the number of elements, it is unsafe
5143 // to examine the mask.
5144 if (BCNumEltsChanged)
5146 unsigned Idx = cast<ConstantSDNode>(InVec.getOperand(2).
5147 getOperand(Elt))->getZExtValue();
5148 unsigned NumElems = InVec.getOperand(2).getNumOperands();
5149 InVec = (Idx < NumElems) ? InVec.getOperand(0) : InVec.getOperand(1);
5150 if (InVec.getOpcode() == ISD::BIT_CONVERT)
5151 InVec = InVec.getOperand(0);
5152 if (ISD::isNormalLoad(InVec.getNode())) {
5153 LN0 = cast<LoadSDNode>(InVec);
5154 Elt = (Idx < NumElems) ? Idx : Idx - NumElems;
5158 if (!LN0 || !LN0->hasOneUse() || LN0->isVolatile())
5161 unsigned Align = LN0->getAlignment();
5163 // Check the resultant load doesn't need a higher alignment than the
5166 TLI.getTargetData()->getABITypeAlignment(LVT.getTypeForMVT());
5168 if (NewAlign > Align || !TLI.isOperationLegalOrCustom(ISD::LOAD, LVT))
5174 SDValue NewPtr = LN0->getBasePtr();
5176 unsigned PtrOff = LVT.getSizeInBits() * Elt / 8;
5177 MVT PtrType = NewPtr.getValueType();
5178 if (TLI.isBigEndian())
5179 PtrOff = VT.getSizeInBits() / 8 - PtrOff;
5180 NewPtr = DAG.getNode(ISD::ADD, N->getDebugLoc(), PtrType, NewPtr,
5181 DAG.getConstant(PtrOff, PtrType));
5184 return DAG.getLoad(LVT, N->getDebugLoc(), LN0->getChain(), NewPtr,
5185 LN0->getSrcValue(), LN0->getSrcValueOffset(),
5186 LN0->isVolatile(), Align);
5192 SDValue DAGCombiner::visitBUILD_VECTOR(SDNode *N) {
5193 unsigned NumInScalars = N->getNumOperands();
5194 MVT VT = N->getValueType(0);
5195 unsigned NumElts = VT.getVectorNumElements();
5196 MVT EltType = VT.getVectorElementType();
5198 // Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT
5199 // operations. If so, and if the EXTRACT_VECTOR_ELT vector inputs come from
5200 // at most two distinct vectors, turn this into a shuffle node.
5201 SDValue VecIn1, VecIn2;
5202 for (unsigned i = 0; i != NumInScalars; ++i) {
5203 // Ignore undef inputs.
5204 if (N->getOperand(i).getOpcode() == ISD::UNDEF) continue;
5206 // If this input is something other than a EXTRACT_VECTOR_ELT with a
5207 // constant index, bail out.
5208 if (N->getOperand(i).getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
5209 !isa<ConstantSDNode>(N->getOperand(i).getOperand(1))) {
5210 VecIn1 = VecIn2 = SDValue(0, 0);
5214 // If the input vector type disagrees with the result of the build_vector,
5215 // we can't make a shuffle.
5216 SDValue ExtractedFromVec = N->getOperand(i).getOperand(0);
5217 if (ExtractedFromVec.getValueType() != VT) {
5218 VecIn1 = VecIn2 = SDValue(0, 0);
5222 // Otherwise, remember this. We allow up to two distinct input vectors.
5223 if (ExtractedFromVec == VecIn1 || ExtractedFromVec == VecIn2)
5226 if (VecIn1.getNode() == 0) {
5227 VecIn1 = ExtractedFromVec;
5228 } else if (VecIn2.getNode() == 0) {
5229 VecIn2 = ExtractedFromVec;
5232 VecIn1 = VecIn2 = SDValue(0, 0);
5237 // If everything is good, we can make a shuffle operation.
5238 if (VecIn1.getNode()) {
5239 SmallVector<SDValue, 8> BuildVecIndices;
5240 for (unsigned i = 0; i != NumInScalars; ++i) {
5241 if (N->getOperand(i).getOpcode() == ISD::UNDEF) {
5242 BuildVecIndices.push_back(DAG.getUNDEF(TLI.getPointerTy()));
5246 SDValue Extract = N->getOperand(i);
5248 // If extracting from the first vector, just use the index directly.
5249 if (Extract.getOperand(0) == VecIn1) {
5250 BuildVecIndices.push_back(Extract.getOperand(1));
5254 // Otherwise, use InIdx + VecSize
5256 cast<ConstantSDNode>(Extract.getOperand(1))->getZExtValue();
5257 BuildVecIndices.push_back(DAG.getIntPtrConstant(Idx+NumInScalars));
5260 // Add count and size info.
5261 MVT IndexVT = MVT::getIntegerVT(EltType.getSizeInBits());
5262 MVT BuildVecVT = MVT::getVectorVT(IndexVT, NumElts);
5263 if (!TLI.isTypeLegal(BuildVecVT) && LegalTypes)
5266 // Return the new VECTOR_SHUFFLE node.
5269 if (VecIn2.getNode()) {
5272 // Use an undef build_vector as input for the second operand.
5273 std::vector<SDValue> UnOps(NumInScalars,
5274 DAG.getUNDEF(EltType));
5275 Ops[1] = DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(), VT,
5276 &UnOps[0], UnOps.size());
5277 AddToWorkList(Ops[1].getNode());
5280 Ops[2] = DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(), BuildVecVT,
5281 &BuildVecIndices[0], BuildVecIndices.size());
5282 return DAG.getNode(ISD::VECTOR_SHUFFLE, N->getDebugLoc(), VT, Ops, 3);
5288 SDValue DAGCombiner::visitCONCAT_VECTORS(SDNode *N) {
5289 // TODO: Check to see if this is a CONCAT_VECTORS of a bunch of
5290 // EXTRACT_SUBVECTOR operations. If so, and if the EXTRACT_SUBVECTOR vector
5291 // inputs come from at most two distinct vectors, turn this into a shuffle
5294 // If we only have one input vector, we don't need to do any concatenation.
5295 if (N->getNumOperands() == 1)
5296 return N->getOperand(0);
5301 SDValue DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
5302 SDValue ShufMask = N->getOperand(2);
5303 unsigned NumElts = ShufMask.getNumOperands();
5305 SDValue N0 = N->getOperand(0);
5306 SDValue N1 = N->getOperand(1);
5308 assert(N0.getValueType().getVectorNumElements() == NumElts &&
5309 "Vector shuffle must be normalized in DAG");
5311 // If the shuffle mask is an identity operation on the LHS, return the LHS.
5312 bool isIdentity = true;
5313 for (unsigned i = 0; i != NumElts; ++i) {
5314 if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF &&
5315 cast<ConstantSDNode>(ShufMask.getOperand(i))->getZExtValue() != i) {
5320 if (isIdentity) return N->getOperand(0);
5322 // If the shuffle mask is an identity operation on the RHS, return the RHS.
5324 for (unsigned i = 0; i != NumElts; ++i) {
5325 if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF &&
5326 cast<ConstantSDNode>(ShufMask.getOperand(i))->getZExtValue() !=
5332 if (isIdentity) return N->getOperand(1);
5334 // Check if the shuffle is a unary shuffle, i.e. one of the vectors is not
5336 bool isUnary = true;
5337 bool isSplat = true;
5339 unsigned BaseIdx = 0;
5340 for (unsigned i = 0; i != NumElts; ++i)
5341 if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF) {
5342 unsigned Idx=cast<ConstantSDNode>(ShufMask.getOperand(i))->getZExtValue();
5343 int V = (Idx < NumElts) ? 0 : 1;
5357 // Normalize unary shuffle so the RHS is undef.
5358 if (isUnary && VecNum == 1)
5361 // If it is a splat, check if the argument vector is a build_vector with
5362 // all scalar elements the same.
5364 SDNode *V = N0.getNode();
5366 // If this is a bit convert that changes the element type of the vector but
5367 // not the number of vector elements, look through it. Be careful not to
5368 // look though conversions that change things like v4f32 to v2f64.
5369 if (V->getOpcode() == ISD::BIT_CONVERT) {
5370 SDValue ConvInput = V->getOperand(0);
5371 if (ConvInput.getValueType().isVector() &&
5372 ConvInput.getValueType().getVectorNumElements() == NumElts)
5373 V = ConvInput.getNode();
5376 if (V->getOpcode() == ISD::BUILD_VECTOR) {
5377 unsigned NumElems = V->getNumOperands();
5378 if (NumElems > BaseIdx) {
5380 bool AllSame = true;
5381 for (unsigned i = 0; i != NumElems; ++i) {
5382 if (V->getOperand(i).getOpcode() != ISD::UNDEF) {
5383 Base = V->getOperand(i);
5387 // Splat of <u, u, u, u>, return <u, u, u, u>
5388 if (!Base.getNode())
5390 for (unsigned i = 0; i != NumElems; ++i) {
5391 if (V->getOperand(i) != Base) {
5396 // Splat of <x, x, x, x>, return <x, x, x, x>
5403 // If it is a unary or the LHS and the RHS are the same node, turn the RHS
5405 if (isUnary || N0 == N1) {
5406 // Check the SHUFFLE mask, mapping any inputs from the 2nd operand into the
5408 SmallVector<SDValue, 8> MappedOps;
5410 for (unsigned i = 0; i != NumElts; ++i) {
5411 if (ShufMask.getOperand(i).getOpcode() == ISD::UNDEF ||
5412 cast<ConstantSDNode>(ShufMask.getOperand(i))->getZExtValue() <
5414 MappedOps.push_back(ShufMask.getOperand(i));
5417 cast<ConstantSDNode>(ShufMask.getOperand(i))->getZExtValue() -
5419 MappedOps.push_back(DAG.getConstant(NewIdx,
5420 ShufMask.getOperand(i).getValueType()));
5424 ShufMask = DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(),
5425 ShufMask.getValueType(),
5426 &MappedOps[0], MappedOps.size());
5427 AddToWorkList(ShufMask.getNode());
5428 return DAG.getNode(ISD::VECTOR_SHUFFLE, N->getDebugLoc(),
5429 N->getValueType(0), N0,
5430 DAG.getUNDEF(N->getValueType(0)),
5437 /// XformToShuffleWithZero - Returns a vector_shuffle if it able to transform
5438 /// an AND to a vector_shuffle with the destination vector and a zero vector.
5439 /// e.g. AND V, <0xffffffff, 0, 0xffffffff, 0>. ==>
5440 /// vector_shuffle V, Zero, <0, 4, 2, 4>
5441 SDValue DAGCombiner::XformToShuffleWithZero(SDNode *N) {
5442 SDValue LHS = N->getOperand(0);
5443 SDValue RHS = N->getOperand(1);
5444 if (N->getOpcode() == ISD::AND) {
5445 if (RHS.getOpcode() == ISD::BIT_CONVERT)
5446 RHS = RHS.getOperand(0);
5447 if (RHS.getOpcode() == ISD::BUILD_VECTOR) {
5448 std::vector<SDValue> IdxOps;
5449 unsigned NumOps = RHS.getNumOperands();
5450 unsigned NumElts = NumOps;
5451 for (unsigned i = 0; i != NumElts; ++i) {
5452 SDValue Elt = RHS.getOperand(i);
5453 if (!isa<ConstantSDNode>(Elt))
5455 else if (cast<ConstantSDNode>(Elt)->isAllOnesValue())
5456 IdxOps.push_back(DAG.getIntPtrConstant(i));
5457 else if (cast<ConstantSDNode>(Elt)->isNullValue())
5458 IdxOps.push_back(DAG.getIntPtrConstant(NumElts));
5463 // Let's see if the target supports this vector_shuffle.
5464 if (!TLI.isVectorClearMaskLegal(IdxOps, TLI.getPointerTy(), DAG))
5467 // Return the new VECTOR_SHUFFLE node.
5468 MVT EVT = RHS.getValueType().getVectorElementType();
5469 MVT VT = MVT::getVectorVT(EVT, NumElts);
5470 MVT MaskVT = MVT::getVectorVT(TLI.getPointerTy(), NumElts);
5471 std::vector<SDValue> Ops;
5472 LHS = DAG.getNode(ISD::BIT_CONVERT, LHS.getDebugLoc(), VT, LHS);
5474 AddToWorkList(LHS.getNode());
5475 std::vector<SDValue> ZeroOps(NumElts, DAG.getConstant(0, EVT));
5476 Ops.push_back(DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(),
5477 VT, &ZeroOps[0], ZeroOps.size()));
5478 Ops.push_back(DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(),
5479 MaskVT, &IdxOps[0], IdxOps.size()));
5480 SDValue Result = DAG.getNode(ISD::VECTOR_SHUFFLE, N->getDebugLoc(),
5481 VT, &Ops[0], Ops.size());
5483 if (VT != N->getValueType(0))
5484 Result = DAG.getNode(ISD::BIT_CONVERT, N->getDebugLoc(),
5485 N->getValueType(0), Result);
5494 /// SimplifyVBinOp - Visit a binary vector operation, like ADD.
5495 SDValue DAGCombiner::SimplifyVBinOp(SDNode *N) {
5496 // After legalize, the target may be depending on adds and other
5497 // binary ops to provide legal ways to construct constants or other
5498 // things. Simplifying them may result in a loss of legality.
5499 if (LegalOperations) return SDValue();
5501 MVT VT = N->getValueType(0);
5502 assert(VT.isVector() && "SimplifyVBinOp only works on vectors!");
5504 MVT EltType = VT.getVectorElementType();
5505 SDValue LHS = N->getOperand(0);
5506 SDValue RHS = N->getOperand(1);
5507 SDValue Shuffle = XformToShuffleWithZero(N);
5508 if (Shuffle.getNode()) return Shuffle;
5510 // If the LHS and RHS are BUILD_VECTOR nodes, see if we can constant fold
5512 if (LHS.getOpcode() == ISD::BUILD_VECTOR &&
5513 RHS.getOpcode() == ISD::BUILD_VECTOR) {
5514 SmallVector<SDValue, 8> Ops;
5515 for (unsigned i = 0, e = LHS.getNumOperands(); i != e; ++i) {
5516 SDValue LHSOp = LHS.getOperand(i);
5517 SDValue RHSOp = RHS.getOperand(i);
5518 // If these two elements can't be folded, bail out.
5519 if ((LHSOp.getOpcode() != ISD::UNDEF &&
5520 LHSOp.getOpcode() != ISD::Constant &&
5521 LHSOp.getOpcode() != ISD::ConstantFP) ||
5522 (RHSOp.getOpcode() != ISD::UNDEF &&
5523 RHSOp.getOpcode() != ISD::Constant &&
5524 RHSOp.getOpcode() != ISD::ConstantFP))
5527 // Can't fold divide by zero.
5528 if (N->getOpcode() == ISD::SDIV || N->getOpcode() == ISD::UDIV ||
5529 N->getOpcode() == ISD::FDIV) {
5530 if ((RHSOp.getOpcode() == ISD::Constant &&
5531 cast<ConstantSDNode>(RHSOp.getNode())->isNullValue()) ||
5532 (RHSOp.getOpcode() == ISD::ConstantFP &&
5533 cast<ConstantFPSDNode>(RHSOp.getNode())->getValueAPF().isZero()))
5537 Ops.push_back(DAG.getNode(N->getOpcode(), LHS.getDebugLoc(),
5538 EltType, LHSOp, RHSOp));
5539 AddToWorkList(Ops.back().getNode());
5540 assert((Ops.back().getOpcode() == ISD::UNDEF ||
5541 Ops.back().getOpcode() == ISD::Constant ||
5542 Ops.back().getOpcode() == ISD::ConstantFP) &&
5543 "Scalar binop didn't fold!");
5546 if (Ops.size() == LHS.getNumOperands()) {
5547 MVT VT = LHS.getValueType();
5548 return DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(), VT,
5549 &Ops[0], Ops.size());
5556 SDValue DAGCombiner::SimplifySelect(DebugLoc DL, SDValue N0,
5557 SDValue N1, SDValue N2){
5558 assert(N0.getOpcode() ==ISD::SETCC && "First argument must be a SetCC node!");
5560 SDValue SCC = SimplifySelectCC(DL, N0.getOperand(0), N0.getOperand(1), N1, N2,
5561 cast<CondCodeSDNode>(N0.getOperand(2))->get());
5563 // If we got a simplified select_cc node back from SimplifySelectCC, then
5564 // break it down into a new SETCC node, and a new SELECT node, and then return
5565 // the SELECT node, since we were called with a SELECT node.
5566 if (SCC.getNode()) {
5567 // Check to see if we got a select_cc back (to turn into setcc/select).
5568 // Otherwise, just return whatever node we got back, like fabs.
5569 if (SCC.getOpcode() == ISD::SELECT_CC) {
5570 SDValue SETCC = DAG.getNode(ISD::SETCC, N0.getDebugLoc(),
5572 SCC.getOperand(0), SCC.getOperand(1),
5574 AddToWorkList(SETCC.getNode());
5575 return DAG.getNode(ISD::SELECT, SCC.getDebugLoc(), SCC.getValueType(),
5576 SCC.getOperand(2), SCC.getOperand(3), SETCC);
5584 /// SimplifySelectOps - Given a SELECT or a SELECT_CC node, where LHS and RHS
5585 /// are the two values being selected between, see if we can simplify the
5586 /// select. Callers of this should assume that TheSelect is deleted if this
5587 /// returns true. As such, they should return the appropriate thing (e.g. the
5588 /// node) back to the top-level of the DAG combiner loop to avoid it being
5590 bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS,
5593 // If this is a select from two identical things, try to pull the operation
5594 // through the select.
5595 if (LHS.getOpcode() == RHS.getOpcode() && LHS.hasOneUse() && RHS.hasOneUse()){
5596 // If this is a load and the token chain is identical, replace the select
5597 // of two loads with a load through a select of the address to load from.
5598 // This triggers in things like "select bool X, 10.0, 123.0" after the FP
5599 // constants have been dropped into the constant pool.
5600 if (LHS.getOpcode() == ISD::LOAD &&
5601 // Do not let this transformation reduce the number of volatile loads.
5602 !cast<LoadSDNode>(LHS)->isVolatile() &&
5603 !cast<LoadSDNode>(RHS)->isVolatile() &&
5604 // Token chains must be identical.
5605 LHS.getOperand(0) == RHS.getOperand(0)) {
5606 LoadSDNode *LLD = cast<LoadSDNode>(LHS);
5607 LoadSDNode *RLD = cast<LoadSDNode>(RHS);
5609 // If this is an EXTLOAD, the VT's must match.
5610 if (LLD->getMemoryVT() == RLD->getMemoryVT()) {
5611 // FIXME: this conflates two src values, discarding one. This is not
5612 // the right thing to do, but nothing uses srcvalues now. When they do,
5613 // turn SrcValue into a list of locations.
5615 if (TheSelect->getOpcode() == ISD::SELECT) {
5616 // Check that the condition doesn't reach either load. If so, folding
5617 // this will induce a cycle into the DAG.
5618 if (!LLD->isPredecessorOf(TheSelect->getOperand(0).getNode()) &&
5619 !RLD->isPredecessorOf(TheSelect->getOperand(0).getNode())) {
5620 Addr = DAG.getNode(ISD::SELECT, TheSelect->getDebugLoc(),
5621 LLD->getBasePtr().getValueType(),
5622 TheSelect->getOperand(0), LLD->getBasePtr(),
5626 // Check that the condition doesn't reach either load. If so, folding
5627 // this will induce a cycle into the DAG.
5628 if (!LLD->isPredecessorOf(TheSelect->getOperand(0).getNode()) &&
5629 !RLD->isPredecessorOf(TheSelect->getOperand(0).getNode()) &&
5630 !LLD->isPredecessorOf(TheSelect->getOperand(1).getNode()) &&
5631 !RLD->isPredecessorOf(TheSelect->getOperand(1).getNode())) {
5632 Addr = DAG.getNode(ISD::SELECT_CC, TheSelect->getDebugLoc(),
5633 LLD->getBasePtr().getValueType(),
5634 TheSelect->getOperand(0),
5635 TheSelect->getOperand(1),
5636 LLD->getBasePtr(), RLD->getBasePtr(),
5637 TheSelect->getOperand(4));
5641 if (Addr.getNode()) {
5643 if (LLD->getExtensionType() == ISD::NON_EXTLOAD) {
5644 Load = DAG.getLoad(TheSelect->getValueType(0),
5645 TheSelect->getDebugLoc(),
5647 Addr,LLD->getSrcValue(),
5648 LLD->getSrcValueOffset(),
5650 LLD->getAlignment());
5652 Load = DAG.getExtLoad(LLD->getExtensionType(),
5653 TheSelect->getDebugLoc(),
5654 TheSelect->getValueType(0),
5655 LLD->getChain(), Addr, LLD->getSrcValue(),
5656 LLD->getSrcValueOffset(),
5659 LLD->getAlignment());
5662 // Users of the select now use the result of the load.
5663 CombineTo(TheSelect, Load);
5665 // Users of the old loads now use the new load's chain. We know the
5666 // old-load value is dead now.
5667 CombineTo(LHS.getNode(), Load.getValue(0), Load.getValue(1));
5668 CombineTo(RHS.getNode(), Load.getValue(0), Load.getValue(1));
5678 SDValue DAGCombiner::SimplifySelectCC(DebugLoc DL, SDValue N0, SDValue N1,
5679 SDValue N2, SDValue N3,
5680 ISD::CondCode CC, bool NotExtCompare) {
5681 MVT VT = N2.getValueType();
5682 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
5683 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.getNode());
5684 ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N3.getNode());
5686 // Determine if the condition we're dealing with is constant
5687 SDValue SCC = SimplifySetCC(TLI.getSetCCResultType(N0.getValueType()),
5688 N0, N1, CC, DL, false);
5689 if (SCC.getNode()) AddToWorkList(SCC.getNode());
5690 ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.getNode());
5692 // fold select_cc true, x, y -> x
5693 if (SCCC && !SCCC->isNullValue())
5695 // fold select_cc false, x, y -> y
5696 if (SCCC && SCCC->isNullValue())
5699 // Check to see if we can simplify the select into an fabs node
5700 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1)) {
5701 // Allow either -0.0 or 0.0
5702 if (CFP->getValueAPF().isZero()) {
5703 // select (setg[te] X, +/-0.0), X, fneg(X) -> fabs
5704 if ((CC == ISD::SETGE || CC == ISD::SETGT) &&
5705 N0 == N2 && N3.getOpcode() == ISD::FNEG &&
5706 N2 == N3.getOperand(0))
5707 return DAG.getNode(ISD::FABS, DL, VT, N0);
5709 // select (setl[te] X, +/-0.0), fneg(X), X -> fabs
5710 if ((CC == ISD::SETLT || CC == ISD::SETLE) &&
5711 N0 == N3 && N2.getOpcode() == ISD::FNEG &&
5712 N2.getOperand(0) == N3)
5713 return DAG.getNode(ISD::FABS, DL, VT, N3);
5717 // Check to see if we can perform the "gzip trick", transforming
5718 // (select_cc setlt X, 0, A, 0) -> (and (sra X, (sub size(X), 1), A)
5719 if (N1C && N3C && N3C->isNullValue() && CC == ISD::SETLT &&
5720 N0.getValueType().isInteger() &&
5721 N2.getValueType().isInteger() &&
5722 (N1C->isNullValue() || // (a < 0) ? b : 0
5723 (N1C->getAPIntValue() == 1 && N0 == N2))) { // (a < 1) ? a : 0
5724 MVT XType = N0.getValueType();
5725 MVT AType = N2.getValueType();
5726 if (XType.bitsGE(AType)) {
5727 // and (sra X, size(X)-1, A) -> "and (srl X, C2), A" iff A is a
5728 // single-bit constant.
5729 if (N2C && ((N2C->getAPIntValue() & (N2C->getAPIntValue()-1)) == 0)) {
5730 unsigned ShCtV = N2C->getAPIntValue().logBase2();
5731 ShCtV = XType.getSizeInBits()-ShCtV-1;
5732 SDValue ShCt = DAG.getConstant(ShCtV, getShiftAmountTy());
5733 SDValue Shift = DAG.getNode(ISD::SRL, N0.getDebugLoc(),
5735 AddToWorkList(Shift.getNode());
5737 if (XType.bitsGT(AType)) {
5738 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
5739 AddToWorkList(Shift.getNode());
5742 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
5745 SDValue Shift = DAG.getNode(ISD::SRA, N0.getDebugLoc(),
5747 DAG.getConstant(XType.getSizeInBits()-1,
5748 getShiftAmountTy()));
5749 AddToWorkList(Shift.getNode());
5751 if (XType.bitsGT(AType)) {
5752 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
5753 AddToWorkList(Shift.getNode());
5756 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
5760 // fold select C, 16, 0 -> shl C, 4
5761 if (N2C && N3C && N3C->isNullValue() && N2C->getAPIntValue().isPowerOf2() &&
5762 TLI.getBooleanContents() == TargetLowering::ZeroOrOneBooleanContent) {
5764 // If the caller doesn't want us to simplify this into a zext of a compare,
5766 if (NotExtCompare && N2C->getAPIntValue() == 1)
5769 // Get a SetCC of the condition
5770 // FIXME: Should probably make sure that setcc is legal if we ever have a
5771 // target where it isn't.
5773 // cast from setcc result type to select result type
5775 SCC = DAG.getSetCC(DL, TLI.getSetCCResultType(N0.getValueType()),
5777 if (N2.getValueType().bitsLT(SCC.getValueType()))
5778 Temp = DAG.getZeroExtendInReg(SCC, N2.getDebugLoc(), N2.getValueType());
5780 Temp = DAG.getNode(ISD::ZERO_EXTEND, N2.getDebugLoc(),
5781 N2.getValueType(), SCC);
5783 SCC = DAG.getSetCC(N0.getDebugLoc(), MVT::i1, N0, N1, CC);
5784 Temp = DAG.getNode(ISD::ZERO_EXTEND, N2.getDebugLoc(),
5785 N2.getValueType(), SCC);
5788 AddToWorkList(SCC.getNode());
5789 AddToWorkList(Temp.getNode());
5791 if (N2C->getAPIntValue() == 1)
5794 // shl setcc result by log2 n2c
5795 return DAG.getNode(ISD::SHL, DL, N2.getValueType(), Temp,
5796 DAG.getConstant(N2C->getAPIntValue().logBase2(),
5797 getShiftAmountTy()));
5800 // Check to see if this is the equivalent of setcc
5801 // FIXME: Turn all of these into setcc if setcc if setcc is legal
5802 // otherwise, go ahead with the folds.
5803 if (0 && N3C && N3C->isNullValue() && N2C && (N2C->getAPIntValue() == 1ULL)) {
5804 MVT XType = N0.getValueType();
5805 if (!LegalOperations ||
5806 TLI.isOperationLegal(ISD::SETCC, TLI.getSetCCResultType(XType))) {
5807 SDValue Res = DAG.getSetCC(DL, TLI.getSetCCResultType(XType), N0, N1, CC);
5808 if (Res.getValueType() != VT)
5809 Res = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Res);
5813 // fold (seteq X, 0) -> (srl (ctlz X, log2(size(X))))
5814 if (N1C && N1C->isNullValue() && CC == ISD::SETEQ &&
5815 (!LegalOperations ||
5816 TLI.isOperationLegal(ISD::CTLZ, XType))) {
5817 SDValue Ctlz = DAG.getNode(ISD::CTLZ, N0.getDebugLoc(), XType, N0);
5818 return DAG.getNode(ISD::SRL, DL, XType, Ctlz,
5819 DAG.getConstant(Log2_32(XType.getSizeInBits()),
5820 getShiftAmountTy()));
5822 // fold (setgt X, 0) -> (srl (and (-X, ~X), size(X)-1))
5823 if (N1C && N1C->isNullValue() && CC == ISD::SETGT) {
5824 SDValue NegN0 = DAG.getNode(ISD::SUB, N0.getDebugLoc(),
5825 XType, DAG.getConstant(0, XType), N0);
5826 SDValue NotN0 = DAG.getNOT(N0.getDebugLoc(), N0, XType);
5827 return DAG.getNode(ISD::SRL, DL, XType,
5828 DAG.getNode(ISD::AND, DL, XType, NegN0, NotN0),
5829 DAG.getConstant(XType.getSizeInBits()-1,
5830 getShiftAmountTy()));
5832 // fold (setgt X, -1) -> (xor (srl (X, size(X)-1), 1))
5833 if (N1C && N1C->isAllOnesValue() && CC == ISD::SETGT) {
5834 SDValue Sign = DAG.getNode(ISD::SRL, N0.getDebugLoc(), XType, N0,
5835 DAG.getConstant(XType.getSizeInBits()-1,
5836 getShiftAmountTy()));
5837 return DAG.getNode(ISD::XOR, DL, XType, Sign, DAG.getConstant(1, XType));
5841 // Check to see if this is an integer abs. select_cc setl[te] X, 0, -X, X ->
5842 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
5843 if (N1C && N1C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE) &&
5844 N0 == N3 && N2.getOpcode() == ISD::SUB && N0 == N2.getOperand(1) &&
5845 N2.getOperand(0) == N1 && N0.getValueType().isInteger()) {
5846 MVT XType = N0.getValueType();
5847 SDValue Shift = DAG.getNode(ISD::SRA, N0.getDebugLoc(), XType, N0,
5848 DAG.getConstant(XType.getSizeInBits()-1,
5849 getShiftAmountTy()));
5850 SDValue Add = DAG.getNode(ISD::ADD, N0.getDebugLoc(), XType,
5852 AddToWorkList(Shift.getNode());
5853 AddToWorkList(Add.getNode());
5854 return DAG.getNode(ISD::XOR, DL, XType, Add, Shift);
5856 // Check to see if this is an integer abs. select_cc setgt X, -1, X, -X ->
5857 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
5858 if (N1C && N1C->isAllOnesValue() && CC == ISD::SETGT &&
5859 N0 == N2 && N3.getOpcode() == ISD::SUB && N0 == N3.getOperand(1)) {
5860 if (ConstantSDNode *SubC = dyn_cast<ConstantSDNode>(N3.getOperand(0))) {
5861 MVT XType = N0.getValueType();
5862 if (SubC->isNullValue() && XType.isInteger()) {
5863 SDValue Shift = DAG.getNode(ISD::SRA, N0.getDebugLoc(), XType,
5865 DAG.getConstant(XType.getSizeInBits()-1,
5866 getShiftAmountTy()));
5867 SDValue Add = DAG.getNode(ISD::ADD, N0.getDebugLoc(),
5869 AddToWorkList(Shift.getNode());
5870 AddToWorkList(Add.getNode());
5871 return DAG.getNode(ISD::XOR, DL, XType, Add, Shift);
5879 /// SimplifySetCC - This is a stub for TargetLowering::SimplifySetCC.
5880 SDValue DAGCombiner::SimplifySetCC(MVT VT, SDValue N0,
5881 SDValue N1, ISD::CondCode Cond,
5882 DebugLoc DL, bool foldBooleans) {
5883 TargetLowering::DAGCombinerInfo
5884 DagCombineInfo(DAG, Level == Unrestricted, false, this);
5885 return TLI.SimplifySetCC(VT, N0, N1, Cond, foldBooleans, DagCombineInfo, DL);
5888 /// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
5889 /// return a DAG expression to select that will generate the same value by
5890 /// multiplying by a magic number. See:
5891 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
5892 SDValue DAGCombiner::BuildSDIV(SDNode *N) {
5893 std::vector<SDNode*> Built;
5894 SDValue S = TLI.BuildSDIV(N, DAG, &Built);
5896 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
5902 /// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant,
5903 /// return a DAG expression to select that will generate the same value by
5904 /// multiplying by a magic number. See:
5905 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
5906 SDValue DAGCombiner::BuildUDIV(SDNode *N) {
5907 std::vector<SDNode*> Built;
5908 SDValue S = TLI.BuildUDIV(N, DAG, &Built);
5910 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
5916 /// FindBaseOffset - Return true if base is known not to alias with anything
5917 /// but itself. Provides base object and offset as results.
5918 static bool FindBaseOffset(SDValue Ptr, SDValue &Base, int64_t &Offset) {
5919 // Assume it is a primitive operation.
5920 Base = Ptr; Offset = 0;
5922 // If it's an adding a simple constant then integrate the offset.
5923 if (Base.getOpcode() == ISD::ADD) {
5924 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Base.getOperand(1))) {
5925 Base = Base.getOperand(0);
5926 Offset += C->getZExtValue();
5930 // If it's any of the following then it can't alias with anything but itself.
5931 return isa<FrameIndexSDNode>(Base) ||
5932 isa<ConstantPoolSDNode>(Base) ||
5933 isa<GlobalAddressSDNode>(Base);
5936 /// isAlias - Return true if there is any possibility that the two addresses
5938 bool DAGCombiner::isAlias(SDValue Ptr1, int64_t Size1,
5939 const Value *SrcValue1, int SrcValueOffset1,
5940 SDValue Ptr2, int64_t Size2,
5941 const Value *SrcValue2, int SrcValueOffset2) const {
5942 // If they are the same then they must be aliases.
5943 if (Ptr1 == Ptr2) return true;
5945 // Gather base node and offset information.
5946 SDValue Base1, Base2;
5947 int64_t Offset1, Offset2;
5948 bool KnownBase1 = FindBaseOffset(Ptr1, Base1, Offset1);
5949 bool KnownBase2 = FindBaseOffset(Ptr2, Base2, Offset2);
5951 // If they have a same base address then...
5953 // Check to see if the addresses overlap.
5954 return !((Offset1 + Size1) <= Offset2 || (Offset2 + Size2) <= Offset1);
5956 // If we know both bases then they can't alias.
5957 if (KnownBase1 && KnownBase2) return false;
5959 if (CombinerGlobalAA) {
5960 // Use alias analysis information.
5961 int64_t MinOffset = std::min(SrcValueOffset1, SrcValueOffset2);
5962 int64_t Overlap1 = Size1 + SrcValueOffset1 - MinOffset;
5963 int64_t Overlap2 = Size2 + SrcValueOffset2 - MinOffset;
5964 AliasAnalysis::AliasResult AAResult =
5965 AA.alias(SrcValue1, Overlap1, SrcValue2, Overlap2);
5966 if (AAResult == AliasAnalysis::NoAlias)
5970 // Otherwise we have to assume they alias.
5974 /// FindAliasInfo - Extracts the relevant alias information from the memory
5975 /// node. Returns true if the operand was a load.
5976 bool DAGCombiner::FindAliasInfo(SDNode *N,
5977 SDValue &Ptr, int64_t &Size,
5978 const Value *&SrcValue, int &SrcValueOffset) const {
5979 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
5980 Ptr = LD->getBasePtr();
5981 Size = LD->getMemoryVT().getSizeInBits() >> 3;
5982 SrcValue = LD->getSrcValue();
5983 SrcValueOffset = LD->getSrcValueOffset();
5985 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
5986 Ptr = ST->getBasePtr();
5987 Size = ST->getMemoryVT().getSizeInBits() >> 3;
5988 SrcValue = ST->getSrcValue();
5989 SrcValueOffset = ST->getSrcValueOffset();
5991 assert(0 && "FindAliasInfo expected a memory operand");
5997 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
5998 /// looking for aliasing nodes and adding them to the Aliases vector.
5999 void DAGCombiner::GatherAllAliases(SDNode *N, SDValue OriginalChain,
6000 SmallVector<SDValue, 8> &Aliases) {
6001 SmallVector<SDValue, 8> Chains; // List of chains to visit.
6002 std::set<SDNode *> Visited; // Visited node set.
6004 // Get alias information for node.
6007 const Value *SrcValue;
6009 bool IsLoad = FindAliasInfo(N, Ptr, Size, SrcValue, SrcValueOffset);
6012 Chains.push_back(OriginalChain);
6014 // Look at each chain and determine if it is an alias. If so, add it to the
6015 // aliases list. If not, then continue up the chain looking for the next
6017 while (!Chains.empty()) {
6018 SDValue Chain = Chains.back();
6021 // Don't bother if we've been before.
6022 if (Visited.find(Chain.getNode()) != Visited.end()) continue;
6023 Visited.insert(Chain.getNode());
6025 switch (Chain.getOpcode()) {
6026 case ISD::EntryToken:
6027 // Entry token is ideal chain operand, but handled in FindBetterChain.
6032 // Get alias information for Chain.
6035 const Value *OpSrcValue;
6036 int OpSrcValueOffset;
6037 bool IsOpLoad = FindAliasInfo(Chain.getNode(), OpPtr, OpSize,
6038 OpSrcValue, OpSrcValueOffset);
6040 // If chain is alias then stop here.
6041 if (!(IsLoad && IsOpLoad) &&
6042 isAlias(Ptr, Size, SrcValue, SrcValueOffset,
6043 OpPtr, OpSize, OpSrcValue, OpSrcValueOffset)) {
6044 Aliases.push_back(Chain);
6046 // Look further up the chain.
6047 Chains.push_back(Chain.getOperand(0));
6048 // Clean up old chain.
6049 AddToWorkList(Chain.getNode());
6054 case ISD::TokenFactor:
6055 // We have to check each of the operands of the token factor, so we queue
6056 // then up. Adding the operands to the queue (stack) in reverse order
6057 // maintains the original order and increases the likelihood that getNode
6058 // will find a matching token factor (CSE.)
6059 for (unsigned n = Chain.getNumOperands(); n;)
6060 Chains.push_back(Chain.getOperand(--n));
6061 // Eliminate the token factor if we can.
6062 AddToWorkList(Chain.getNode());
6066 // For all other instructions we will just have to take what we can get.
6067 Aliases.push_back(Chain);
6073 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes, looking
6074 /// for a better chain (aliasing node.)
6075 SDValue DAGCombiner::FindBetterChain(SDNode *N, SDValue OldChain) {
6076 SmallVector<SDValue, 8> Aliases; // Ops for replacing token factor.
6078 // Accumulate all the aliases to this node.
6079 GatherAllAliases(N, OldChain, Aliases);
6081 if (Aliases.size() == 0) {
6082 // If no operands then chain to entry token.
6083 return DAG.getEntryNode();
6084 } else if (Aliases.size() == 1) {
6085 // If a single operand then chain to it. We don't need to revisit it.
6089 // Construct a custom tailored token factor.
6090 SDValue NewChain = DAG.getNode(ISD::TokenFactor, N->getDebugLoc(), MVT::Other,
6091 &Aliases[0], Aliases.size());
6093 // Make sure the old chain gets cleaned up.
6094 if (NewChain != OldChain) AddToWorkList(OldChain.getNode());
6099 // SelectionDAG::Combine - This is the entry point for the file.
6101 void SelectionDAG::Combine(CombineLevel Level, AliasAnalysis &AA, bool Fast) {
6102 /// run - This is the main entry point to this class.
6104 DAGCombiner(*this, AA, Fast).Run(Level);