1 //===-- DAGCombiner.cpp - Implement a DAG node combiner -------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Nate Begeman and is distributed under the
6 // University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This pass combines dag nodes to form fewer, simpler DAG nodes. It can be run
11 // both before and after the DAG is legalized.
13 // FIXME: Missing folds
14 // sdiv, udiv, srem, urem (X, const) where X is an integer can be expanded into
15 // a sequence of multiplies, shifts, and adds. This should be controlled by
16 // some kind of hint from the target that int div is expensive.
17 // various folds of mulh[s,u] by constants such as -1, powers of 2, etc.
19 // FIXME: select C, pow2, pow2 -> something smart
20 // FIXME: trunc(select X, Y, Z) -> select X, trunc(Y), trunc(Z)
21 // FIXME: Dead stores -> nuke
22 // FIXME: shr X, (and Y,31) -> shr X, Y (TRICKY!)
23 // FIXME: mul (x, const) -> shifts + adds
24 // FIXME: undef values
25 // FIXME: make truncate see through SIGN_EXTEND and AND
26 // FIXME: divide by zero is currently left unfolded. do we want to turn this
28 // FIXME: select ne (select cc, 1, 0), 0, true, false -> select cc, true, false
30 //===----------------------------------------------------------------------===//
32 #define DEBUG_TYPE "dagcombine"
33 #include "llvm/ADT/Statistic.h"
34 #include "llvm/CodeGen/SelectionDAG.h"
35 #include "llvm/Support/Debug.h"
36 #include "llvm/Support/MathExtras.h"
37 #include "llvm/Target/TargetLowering.h"
38 #include "llvm/Support/Visibility.h"
45 static Statistic<> NodesCombined ("dagcombiner",
46 "Number of dag nodes combined");
48 class VISIBILITY_HIDDEN DAGCombiner {
53 // Worklist of all of the nodes that need to be simplified.
54 std::vector<SDNode*> WorkList;
56 /// AddUsersToWorkList - When an instruction is simplified, add all users of
57 /// the instruction to the work lists because they might get more simplified
60 void AddUsersToWorkList(SDNode *N) {
61 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
63 WorkList.push_back(*UI);
66 /// removeFromWorkList - remove all instances of N from the worklist.
68 void removeFromWorkList(SDNode *N) {
69 WorkList.erase(std::remove(WorkList.begin(), WorkList.end(), N),
74 void AddToWorkList(SDNode *N) {
75 WorkList.push_back(N);
78 SDOperand CombineTo(SDNode *N, const std::vector<SDOperand> &To) {
80 DEBUG(std::cerr << "\nReplacing "; N->dump();
81 std::cerr << "\nWith: "; To[0].Val->dump(&DAG);
82 std::cerr << " and " << To.size()-1 << " other values\n");
83 std::vector<SDNode*> NowDead;
84 DAG.ReplaceAllUsesWith(N, To, &NowDead);
86 // Push the new nodes and any users onto the worklist
87 for (unsigned i = 0, e = To.size(); i != e; ++i) {
88 WorkList.push_back(To[i].Val);
89 AddUsersToWorkList(To[i].Val);
92 // Nodes can end up on the worklist more than once. Make sure we do
93 // not process a node that has been replaced.
94 removeFromWorkList(N);
95 for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
96 removeFromWorkList(NowDead[i]);
98 // Finally, since the node is now dead, remove it from the graph.
100 return SDOperand(N, 0);
103 SDOperand CombineTo(SDNode *N, SDOperand Res) {
104 std::vector<SDOperand> To;
106 return CombineTo(N, To);
109 SDOperand CombineTo(SDNode *N, SDOperand Res0, SDOperand Res1) {
110 std::vector<SDOperand> To;
113 return CombineTo(N, To);
117 /// SimplifyDemandedBits - Check the specified integer node value to see if
118 /// it can be simplified or if things it uses can be simplified by bit
119 /// propagation. If so, return true.
120 bool SimplifyDemandedBits(SDOperand Op) {
121 TargetLowering::TargetLoweringOpt TLO(DAG);
122 uint64_t KnownZero, KnownOne;
123 uint64_t Demanded = MVT::getIntVTBitMask(Op.getValueType());
124 if (!TLI.SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO))
128 WorkList.push_back(Op.Val);
130 // Replace the old value with the new one.
132 DEBUG(std::cerr << "\nReplacing "; TLO.Old.Val->dump();
133 std::cerr << "\nWith: "; TLO.New.Val->dump(&DAG));
135 std::vector<SDNode*> NowDead;
136 DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New, NowDead);
138 // Push the new node and any (possibly new) users onto the worklist.
139 WorkList.push_back(TLO.New.Val);
140 AddUsersToWorkList(TLO.New.Val);
142 // Nodes can end up on the worklist more than once. Make sure we do
143 // not process a node that has been replaced.
144 for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
145 removeFromWorkList(NowDead[i]);
147 // Finally, if the node is now dead, remove it from the graph. The node
148 // may not be dead if the replacement process recursively simplified to
149 // something else needing this node.
150 if (TLO.Old.Val->use_empty()) {
151 removeFromWorkList(TLO.Old.Val);
152 DAG.DeleteNode(TLO.Old.Val);
157 /// visit - call the node-specific routine that knows how to fold each
158 /// particular type of node.
159 SDOperand visit(SDNode *N);
161 // Visitation implementation - Implement dag node combining for different
162 // node types. The semantics are as follows:
164 // SDOperand.Val == 0 - No change was made
165 // SDOperand.Val == N - N was replaced, is dead, and is already handled.
166 // otherwise - N should be replaced by the returned Operand.
168 SDOperand visitTokenFactor(SDNode *N);
169 SDOperand visitADD(SDNode *N);
170 SDOperand visitSUB(SDNode *N);
171 SDOperand visitMUL(SDNode *N);
172 SDOperand visitSDIV(SDNode *N);
173 SDOperand visitUDIV(SDNode *N);
174 SDOperand visitSREM(SDNode *N);
175 SDOperand visitUREM(SDNode *N);
176 SDOperand visitMULHU(SDNode *N);
177 SDOperand visitMULHS(SDNode *N);
178 SDOperand visitAND(SDNode *N);
179 SDOperand visitOR(SDNode *N);
180 SDOperand visitXOR(SDNode *N);
181 SDOperand visitVBinOp(SDNode *N, ISD::NodeType IntOp, ISD::NodeType FPOp);
182 SDOperand visitSHL(SDNode *N);
183 SDOperand visitSRA(SDNode *N);
184 SDOperand visitSRL(SDNode *N);
185 SDOperand visitCTLZ(SDNode *N);
186 SDOperand visitCTTZ(SDNode *N);
187 SDOperand visitCTPOP(SDNode *N);
188 SDOperand visitSELECT(SDNode *N);
189 SDOperand visitSELECT_CC(SDNode *N);
190 SDOperand visitSETCC(SDNode *N);
191 SDOperand visitSIGN_EXTEND(SDNode *N);
192 SDOperand visitZERO_EXTEND(SDNode *N);
193 SDOperand visitANY_EXTEND(SDNode *N);
194 SDOperand visitSIGN_EXTEND_INREG(SDNode *N);
195 SDOperand visitTRUNCATE(SDNode *N);
196 SDOperand visitBIT_CONVERT(SDNode *N);
197 SDOperand visitVBIT_CONVERT(SDNode *N);
198 SDOperand visitFADD(SDNode *N);
199 SDOperand visitFSUB(SDNode *N);
200 SDOperand visitFMUL(SDNode *N);
201 SDOperand visitFDIV(SDNode *N);
202 SDOperand visitFREM(SDNode *N);
203 SDOperand visitFCOPYSIGN(SDNode *N);
204 SDOperand visitSINT_TO_FP(SDNode *N);
205 SDOperand visitUINT_TO_FP(SDNode *N);
206 SDOperand visitFP_TO_SINT(SDNode *N);
207 SDOperand visitFP_TO_UINT(SDNode *N);
208 SDOperand visitFP_ROUND(SDNode *N);
209 SDOperand visitFP_ROUND_INREG(SDNode *N);
210 SDOperand visitFP_EXTEND(SDNode *N);
211 SDOperand visitFNEG(SDNode *N);
212 SDOperand visitFABS(SDNode *N);
213 SDOperand visitBRCOND(SDNode *N);
214 SDOperand visitBR_CC(SDNode *N);
215 SDOperand visitLOAD(SDNode *N);
216 SDOperand visitXEXTLOAD(SDNode *N);
217 SDOperand visitSTORE(SDNode *N);
218 SDOperand visitINSERT_VECTOR_ELT(SDNode *N);
219 SDOperand visitVINSERT_VECTOR_ELT(SDNode *N);
220 SDOperand visitVBUILD_VECTOR(SDNode *N);
221 SDOperand visitVECTOR_SHUFFLE(SDNode *N);
222 SDOperand visitVVECTOR_SHUFFLE(SDNode *N);
224 SDOperand XformToShuffleWithZero(SDNode *N);
225 SDOperand ReassociateOps(unsigned Opc, SDOperand LHS, SDOperand RHS);
227 bool SimplifySelectOps(SDNode *SELECT, SDOperand LHS, SDOperand RHS);
228 SDOperand SimplifyBinOpWithSameOpcodeHands(SDNode *N);
229 SDOperand SimplifySelect(SDOperand N0, SDOperand N1, SDOperand N2);
230 SDOperand SimplifySelectCC(SDOperand N0, SDOperand N1, SDOperand N2,
231 SDOperand N3, ISD::CondCode CC);
232 SDOperand SimplifySetCC(MVT::ValueType VT, SDOperand N0, SDOperand N1,
233 ISD::CondCode Cond, bool foldBooleans = true);
234 SDOperand ConstantFoldVBIT_CONVERTofVBUILD_VECTOR(SDNode *, MVT::ValueType);
235 SDOperand BuildSDIV(SDNode *N);
236 SDOperand BuildUDIV(SDNode *N);
238 DAGCombiner(SelectionDAG &D)
239 : DAG(D), TLI(D.getTargetLoweringInfo()), AfterLegalize(false) {}
241 /// Run - runs the dag combiner on all nodes in the work list
242 void Run(bool RunningAfterLegalize);
246 //===----------------------------------------------------------------------===//
247 // TargetLowering::DAGCombinerInfo implementation
248 //===----------------------------------------------------------------------===//
250 void TargetLowering::DAGCombinerInfo::AddToWorklist(SDNode *N) {
251 ((DAGCombiner*)DC)->AddToWorkList(N);
254 SDOperand TargetLowering::DAGCombinerInfo::
255 CombineTo(SDNode *N, const std::vector<SDOperand> &To) {
256 return ((DAGCombiner*)DC)->CombineTo(N, To);
259 SDOperand TargetLowering::DAGCombinerInfo::
260 CombineTo(SDNode *N, SDOperand Res) {
261 return ((DAGCombiner*)DC)->CombineTo(N, Res);
265 SDOperand TargetLowering::DAGCombinerInfo::
266 CombineTo(SDNode *N, SDOperand Res0, SDOperand Res1) {
267 return ((DAGCombiner*)DC)->CombineTo(N, Res0, Res1);
273 //===----------------------------------------------------------------------===//
276 // isSetCCEquivalent - Return true if this node is a setcc, or is a select_cc
277 // that selects between the values 1 and 0, making it equivalent to a setcc.
278 // Also, set the incoming LHS, RHS, and CC references to the appropriate
279 // nodes based on the type of node we are checking. This simplifies life a
280 // bit for the callers.
281 static bool isSetCCEquivalent(SDOperand N, SDOperand &LHS, SDOperand &RHS,
283 if (N.getOpcode() == ISD::SETCC) {
284 LHS = N.getOperand(0);
285 RHS = N.getOperand(1);
286 CC = N.getOperand(2);
289 if (N.getOpcode() == ISD::SELECT_CC &&
290 N.getOperand(2).getOpcode() == ISD::Constant &&
291 N.getOperand(3).getOpcode() == ISD::Constant &&
292 cast<ConstantSDNode>(N.getOperand(2))->getValue() == 1 &&
293 cast<ConstantSDNode>(N.getOperand(3))->isNullValue()) {
294 LHS = N.getOperand(0);
295 RHS = N.getOperand(1);
296 CC = N.getOperand(4);
302 // isOneUseSetCC - Return true if this is a SetCC-equivalent operation with only
303 // one use. If this is true, it allows the users to invert the operation for
304 // free when it is profitable to do so.
305 static bool isOneUseSetCC(SDOperand N) {
306 SDOperand N0, N1, N2;
307 if (isSetCCEquivalent(N, N0, N1, N2) && N.Val->hasOneUse())
312 // FIXME: This should probably go in the ISD class rather than being duplicated
314 static bool isCommutativeBinOp(unsigned Opcode) {
320 case ISD::XOR: return true;
321 default: return false; // FIXME: Need commutative info for user ops!
325 SDOperand DAGCombiner::ReassociateOps(unsigned Opc, SDOperand N0, SDOperand N1){
326 MVT::ValueType VT = N0.getValueType();
327 // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one use
328 // reassoc. (op (op x, c1), c2) -> (op x, (op c1, c2))
329 if (N0.getOpcode() == Opc && isa<ConstantSDNode>(N0.getOperand(1))) {
330 if (isa<ConstantSDNode>(N1)) {
331 SDOperand OpNode = DAG.getNode(Opc, VT, N0.getOperand(1), N1);
332 AddToWorkList(OpNode.Val);
333 return DAG.getNode(Opc, VT, OpNode, N0.getOperand(0));
334 } else if (N0.hasOneUse()) {
335 SDOperand OpNode = DAG.getNode(Opc, VT, N0.getOperand(0), N1);
336 AddToWorkList(OpNode.Val);
337 return DAG.getNode(Opc, VT, OpNode, N0.getOperand(1));
340 // reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) iff x+c1 has one use
341 // reassoc. (op c2, (op x, c1)) -> (op x, (op c1, c2))
342 if (N1.getOpcode() == Opc && isa<ConstantSDNode>(N1.getOperand(1))) {
343 if (isa<ConstantSDNode>(N0)) {
344 SDOperand OpNode = DAG.getNode(Opc, VT, N1.getOperand(1), N0);
345 AddToWorkList(OpNode.Val);
346 return DAG.getNode(Opc, VT, OpNode, N1.getOperand(0));
347 } else if (N1.hasOneUse()) {
348 SDOperand OpNode = DAG.getNode(Opc, VT, N1.getOperand(0), N0);
349 AddToWorkList(OpNode.Val);
350 return DAG.getNode(Opc, VT, OpNode, N1.getOperand(1));
356 void DAGCombiner::Run(bool RunningAfterLegalize) {
357 // set the instance variable, so that the various visit routines may use it.
358 AfterLegalize = RunningAfterLegalize;
360 // Add all the dag nodes to the worklist.
361 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
362 E = DAG.allnodes_end(); I != E; ++I)
363 WorkList.push_back(I);
365 // Create a dummy node (which is not added to allnodes), that adds a reference
366 // to the root node, preventing it from being deleted, and tracking any
367 // changes of the root.
368 HandleSDNode Dummy(DAG.getRoot());
371 /// DagCombineInfo - Expose the DAG combiner to the target combiner impls.
372 TargetLowering::DAGCombinerInfo
373 DagCombineInfo(DAG, !RunningAfterLegalize, this);
375 // while the worklist isn't empty, inspect the node on the end of it and
376 // try and combine it.
377 while (!WorkList.empty()) {
378 SDNode *N = WorkList.back();
381 // If N has no uses, it is dead. Make sure to revisit all N's operands once
382 // N is deleted from the DAG, since they too may now be dead or may have a
383 // reduced number of uses, allowing other xforms.
384 if (N->use_empty() && N != &Dummy) {
385 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
386 WorkList.push_back(N->getOperand(i).Val);
388 removeFromWorkList(N);
393 SDOperand RV = visit(N);
395 // If nothing happened, try a target-specific DAG combine.
397 assert(N->getOpcode() != ISD::DELETED_NODE &&
398 "Node was deleted but visit returned NULL!");
399 if (N->getOpcode() >= ISD::BUILTIN_OP_END ||
400 TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode()))
401 RV = TLI.PerformDAGCombine(N, DagCombineInfo);
406 // If we get back the same node we passed in, rather than a new node or
407 // zero, we know that the node must have defined multiple values and
408 // CombineTo was used. Since CombineTo takes care of the worklist
409 // mechanics for us, we have no work to do in this case.
411 assert(N->getOpcode() != ISD::DELETED_NODE &&
412 RV.Val->getOpcode() != ISD::DELETED_NODE &&
413 "Node was deleted but visit returned new node!");
415 DEBUG(std::cerr << "\nReplacing "; N->dump();
416 std::cerr << "\nWith: "; RV.Val->dump(&DAG);
418 std::vector<SDNode*> NowDead;
419 DAG.ReplaceAllUsesWith(N, std::vector<SDOperand>(1, RV), &NowDead);
421 // Push the new node and any users onto the worklist
422 WorkList.push_back(RV.Val);
423 AddUsersToWorkList(RV.Val);
425 // Nodes can end up on the worklist more than once. Make sure we do
426 // not process a node that has been replaced.
427 removeFromWorkList(N);
428 for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
429 removeFromWorkList(NowDead[i]);
431 // Finally, since the node is now dead, remove it from the graph.
437 // If the root changed (e.g. it was a dead load, update the root).
438 DAG.setRoot(Dummy.getValue());
441 SDOperand DAGCombiner::visit(SDNode *N) {
442 switch(N->getOpcode()) {
444 case ISD::TokenFactor: return visitTokenFactor(N);
445 case ISD::ADD: return visitADD(N);
446 case ISD::SUB: return visitSUB(N);
447 case ISD::MUL: return visitMUL(N);
448 case ISD::SDIV: return visitSDIV(N);
449 case ISD::UDIV: return visitUDIV(N);
450 case ISD::SREM: return visitSREM(N);
451 case ISD::UREM: return visitUREM(N);
452 case ISD::MULHU: return visitMULHU(N);
453 case ISD::MULHS: return visitMULHS(N);
454 case ISD::AND: return visitAND(N);
455 case ISD::OR: return visitOR(N);
456 case ISD::XOR: return visitXOR(N);
457 case ISD::SHL: return visitSHL(N);
458 case ISD::SRA: return visitSRA(N);
459 case ISD::SRL: return visitSRL(N);
460 case ISD::CTLZ: return visitCTLZ(N);
461 case ISD::CTTZ: return visitCTTZ(N);
462 case ISD::CTPOP: return visitCTPOP(N);
463 case ISD::SELECT: return visitSELECT(N);
464 case ISD::SELECT_CC: return visitSELECT_CC(N);
465 case ISD::SETCC: return visitSETCC(N);
466 case ISD::SIGN_EXTEND: return visitSIGN_EXTEND(N);
467 case ISD::ZERO_EXTEND: return visitZERO_EXTEND(N);
468 case ISD::ANY_EXTEND: return visitANY_EXTEND(N);
469 case ISD::SIGN_EXTEND_INREG: return visitSIGN_EXTEND_INREG(N);
470 case ISD::TRUNCATE: return visitTRUNCATE(N);
471 case ISD::BIT_CONVERT: return visitBIT_CONVERT(N);
472 case ISD::VBIT_CONVERT: return visitVBIT_CONVERT(N);
473 case ISD::FADD: return visitFADD(N);
474 case ISD::FSUB: return visitFSUB(N);
475 case ISD::FMUL: return visitFMUL(N);
476 case ISD::FDIV: return visitFDIV(N);
477 case ISD::FREM: return visitFREM(N);
478 case ISD::FCOPYSIGN: return visitFCOPYSIGN(N);
479 case ISD::SINT_TO_FP: return visitSINT_TO_FP(N);
480 case ISD::UINT_TO_FP: return visitUINT_TO_FP(N);
481 case ISD::FP_TO_SINT: return visitFP_TO_SINT(N);
482 case ISD::FP_TO_UINT: return visitFP_TO_UINT(N);
483 case ISD::FP_ROUND: return visitFP_ROUND(N);
484 case ISD::FP_ROUND_INREG: return visitFP_ROUND_INREG(N);
485 case ISD::FP_EXTEND: return visitFP_EXTEND(N);
486 case ISD::FNEG: return visitFNEG(N);
487 case ISD::FABS: return visitFABS(N);
488 case ISD::BRCOND: return visitBRCOND(N);
489 case ISD::BR_CC: return visitBR_CC(N);
490 case ISD::LOAD: return visitLOAD(N);
493 case ISD::ZEXTLOAD: return visitXEXTLOAD(N);
494 case ISD::STORE: return visitSTORE(N);
495 case ISD::INSERT_VECTOR_ELT: return visitINSERT_VECTOR_ELT(N);
496 case ISD::VINSERT_VECTOR_ELT: return visitVINSERT_VECTOR_ELT(N);
497 case ISD::VBUILD_VECTOR: return visitVBUILD_VECTOR(N);
498 case ISD::VECTOR_SHUFFLE: return visitVECTOR_SHUFFLE(N);
499 case ISD::VVECTOR_SHUFFLE: return visitVVECTOR_SHUFFLE(N);
500 case ISD::VADD: return visitVBinOp(N, ISD::ADD , ISD::FADD);
501 case ISD::VSUB: return visitVBinOp(N, ISD::SUB , ISD::FSUB);
502 case ISD::VMUL: return visitVBinOp(N, ISD::MUL , ISD::FMUL);
503 case ISD::VSDIV: return visitVBinOp(N, ISD::SDIV, ISD::FDIV);
504 case ISD::VUDIV: return visitVBinOp(N, ISD::UDIV, ISD::UDIV);
505 case ISD::VAND: return visitVBinOp(N, ISD::AND , ISD::AND);
506 case ISD::VOR: return visitVBinOp(N, ISD::OR , ISD::OR);
507 case ISD::VXOR: return visitVBinOp(N, ISD::XOR , ISD::XOR);
512 SDOperand DAGCombiner::visitTokenFactor(SDNode *N) {
513 std::vector<SDOperand> Ops;
514 bool Changed = false;
516 // If the token factor has two operands and one is the entry token, replace
517 // the token factor with the other operand.
518 if (N->getNumOperands() == 2) {
519 if (N->getOperand(0).getOpcode() == ISD::EntryToken ||
520 N->getOperand(0) == N->getOperand(1))
521 return N->getOperand(1);
522 if (N->getOperand(1).getOpcode() == ISD::EntryToken)
523 return N->getOperand(0);
526 // fold (tokenfactor (tokenfactor)) -> tokenfactor
527 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
528 SDOperand Op = N->getOperand(i);
529 if (Op.getOpcode() == ISD::TokenFactor && Op.hasOneUse()) {
530 AddToWorkList(Op.Val); // Remove dead node.
532 for (unsigned j = 0, e = Op.getNumOperands(); j != e; ++j)
533 Ops.push_back(Op.getOperand(j));
534 } else if (i == 0 || N->getOperand(i) != N->getOperand(i-1)) {
537 // Deleted an operand that was the same as the last one.
542 return DAG.getNode(ISD::TokenFactor, MVT::Other, Ops);
546 SDOperand DAGCombiner::visitADD(SDNode *N) {
547 SDOperand N0 = N->getOperand(0);
548 SDOperand N1 = N->getOperand(1);
549 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
550 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
551 MVT::ValueType VT = N0.getValueType();
553 // fold (add c1, c2) -> c1+c2
555 return DAG.getNode(ISD::ADD, VT, N0, N1);
556 // canonicalize constant to RHS
558 return DAG.getNode(ISD::ADD, VT, N1, N0);
559 // fold (add x, 0) -> x
560 if (N1C && N1C->isNullValue())
562 // fold ((c1-A)+c2) -> (c1+c2)-A
563 if (N1C && N0.getOpcode() == ISD::SUB)
564 if (ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getOperand(0)))
565 return DAG.getNode(ISD::SUB, VT,
566 DAG.getConstant(N1C->getValue()+N0C->getValue(), VT),
569 SDOperand RADD = ReassociateOps(ISD::ADD, N0, N1);
572 // fold ((0-A) + B) -> B-A
573 if (N0.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N0.getOperand(0)) &&
574 cast<ConstantSDNode>(N0.getOperand(0))->isNullValue())
575 return DAG.getNode(ISD::SUB, VT, N1, N0.getOperand(1));
576 // fold (A + (0-B)) -> A-B
577 if (N1.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N1.getOperand(0)) &&
578 cast<ConstantSDNode>(N1.getOperand(0))->isNullValue())
579 return DAG.getNode(ISD::SUB, VT, N0, N1.getOperand(1));
580 // fold (A+(B-A)) -> B
581 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(1))
582 return N1.getOperand(0);
584 if (!MVT::isVector(VT) && SimplifyDemandedBits(SDOperand(N, 0)))
585 return SDOperand(N, 0);
587 // fold (a+b) -> (a|b) iff a and b share no bits.
588 if (MVT::isInteger(VT) && !MVT::isVector(VT)) {
589 uint64_t LHSZero, LHSOne;
590 uint64_t RHSZero, RHSOne;
591 uint64_t Mask = MVT::getIntVTBitMask(VT);
592 TLI.ComputeMaskedBits(N0, Mask, LHSZero, LHSOne);
594 TLI.ComputeMaskedBits(N1, Mask, RHSZero, RHSOne);
596 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
597 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
598 if ((RHSZero & (~LHSZero & Mask)) == (~LHSZero & Mask) ||
599 (LHSZero & (~RHSZero & Mask)) == (~RHSZero & Mask))
600 return DAG.getNode(ISD::OR, VT, N0, N1);
607 SDOperand DAGCombiner::visitSUB(SDNode *N) {
608 SDOperand N0 = N->getOperand(0);
609 SDOperand N1 = N->getOperand(1);
610 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.Val);
611 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
612 MVT::ValueType VT = N0.getValueType();
614 // fold (sub x, x) -> 0
616 return DAG.getConstant(0, N->getValueType(0));
617 // fold (sub c1, c2) -> c1-c2
619 return DAG.getNode(ISD::SUB, VT, N0, N1);
620 // fold (sub x, c) -> (add x, -c)
622 return DAG.getNode(ISD::ADD, VT, N0, DAG.getConstant(-N1C->getValue(), VT));
624 if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1)
625 return N0.getOperand(1);
627 if (N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1)
628 return N0.getOperand(0);
632 SDOperand DAGCombiner::visitMUL(SDNode *N) {
633 SDOperand N0 = N->getOperand(0);
634 SDOperand N1 = N->getOperand(1);
635 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
636 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
637 MVT::ValueType VT = N0.getValueType();
639 // fold (mul c1, c2) -> c1*c2
641 return DAG.getNode(ISD::MUL, VT, N0, N1);
642 // canonicalize constant to RHS
644 return DAG.getNode(ISD::MUL, VT, N1, N0);
645 // fold (mul x, 0) -> 0
646 if (N1C && N1C->isNullValue())
648 // fold (mul x, -1) -> 0-x
649 if (N1C && N1C->isAllOnesValue())
650 return DAG.getNode(ISD::SUB, VT, DAG.getConstant(0, VT), N0);
651 // fold (mul x, (1 << c)) -> x << c
652 if (N1C && isPowerOf2_64(N1C->getValue()))
653 return DAG.getNode(ISD::SHL, VT, N0,
654 DAG.getConstant(Log2_64(N1C->getValue()),
655 TLI.getShiftAmountTy()));
656 // fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c
657 if (N1C && isPowerOf2_64(-N1C->getSignExtended())) {
658 // FIXME: If the input is something that is easily negated (e.g. a
659 // single-use add), we should put the negate there.
660 return DAG.getNode(ISD::SUB, VT, DAG.getConstant(0, VT),
661 DAG.getNode(ISD::SHL, VT, N0,
662 DAG.getConstant(Log2_64(-N1C->getSignExtended()),
663 TLI.getShiftAmountTy())));
666 // (mul (shl X, c1), c2) -> (mul X, c2 << c1)
667 if (N1C && N0.getOpcode() == ISD::SHL &&
668 isa<ConstantSDNode>(N0.getOperand(1))) {
669 SDOperand C3 = DAG.getNode(ISD::SHL, VT, N1, N0.getOperand(1));
670 AddToWorkList(C3.Val);
671 return DAG.getNode(ISD::MUL, VT, N0.getOperand(0), C3);
674 // Change (mul (shl X, C), Y) -> (shl (mul X, Y), C) when the shift has one
677 SDOperand Sh(0,0), Y(0,0);
678 // Check for both (mul (shl X, C), Y) and (mul Y, (shl X, C)).
679 if (N0.getOpcode() == ISD::SHL && isa<ConstantSDNode>(N0.getOperand(1)) &&
680 N0.Val->hasOneUse()) {
682 } else if (N1.getOpcode() == ISD::SHL &&
683 isa<ConstantSDNode>(N1.getOperand(1)) && N1.Val->hasOneUse()) {
687 SDOperand Mul = DAG.getNode(ISD::MUL, VT, Sh.getOperand(0), Y);
688 return DAG.getNode(ISD::SHL, VT, Mul, Sh.getOperand(1));
691 // fold (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2)
692 if (N1C && N0.getOpcode() == ISD::ADD && N0.Val->hasOneUse() &&
693 isa<ConstantSDNode>(N0.getOperand(1))) {
694 return DAG.getNode(ISD::ADD, VT,
695 DAG.getNode(ISD::MUL, VT, N0.getOperand(0), N1),
696 DAG.getNode(ISD::MUL, VT, N0.getOperand(1), N1));
700 SDOperand RMUL = ReassociateOps(ISD::MUL, N0, N1);
706 SDOperand DAGCombiner::visitSDIV(SDNode *N) {
707 SDOperand N0 = N->getOperand(0);
708 SDOperand N1 = N->getOperand(1);
709 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.Val);
710 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
711 MVT::ValueType VT = N->getValueType(0);
713 // fold (sdiv c1, c2) -> c1/c2
714 if (N0C && N1C && !N1C->isNullValue())
715 return DAG.getNode(ISD::SDIV, VT, N0, N1);
716 // fold (sdiv X, 1) -> X
717 if (N1C && N1C->getSignExtended() == 1LL)
719 // fold (sdiv X, -1) -> 0-X
720 if (N1C && N1C->isAllOnesValue())
721 return DAG.getNode(ISD::SUB, VT, DAG.getConstant(0, VT), N0);
722 // If we know the sign bits of both operands are zero, strength reduce to a
723 // udiv instead. Handles (X&15) /s 4 -> X&15 >> 2
724 uint64_t SignBit = 1ULL << (MVT::getSizeInBits(VT)-1);
725 if (TLI.MaskedValueIsZero(N1, SignBit) &&
726 TLI.MaskedValueIsZero(N0, SignBit))
727 return DAG.getNode(ISD::UDIV, N1.getValueType(), N0, N1);
728 // fold (sdiv X, pow2) -> simple ops after legalize
729 if (N1C && N1C->getValue() && !TLI.isIntDivCheap() &&
730 (isPowerOf2_64(N1C->getSignExtended()) ||
731 isPowerOf2_64(-N1C->getSignExtended()))) {
732 // If dividing by powers of two is cheap, then don't perform the following
734 if (TLI.isPow2DivCheap())
736 int64_t pow2 = N1C->getSignExtended();
737 int64_t abs2 = pow2 > 0 ? pow2 : -pow2;
738 unsigned lg2 = Log2_64(abs2);
739 // Splat the sign bit into the register
740 SDOperand SGN = DAG.getNode(ISD::SRA, VT, N0,
741 DAG.getConstant(MVT::getSizeInBits(VT)-1,
742 TLI.getShiftAmountTy()));
743 AddToWorkList(SGN.Val);
744 // Add (N0 < 0) ? abs2 - 1 : 0;
745 SDOperand SRL = DAG.getNode(ISD::SRL, VT, SGN,
746 DAG.getConstant(MVT::getSizeInBits(VT)-lg2,
747 TLI.getShiftAmountTy()));
748 SDOperand ADD = DAG.getNode(ISD::ADD, VT, N0, SRL);
749 AddToWorkList(SRL.Val);
750 AddToWorkList(ADD.Val); // Divide by pow2
751 SDOperand SRA = DAG.getNode(ISD::SRA, VT, ADD,
752 DAG.getConstant(lg2, TLI.getShiftAmountTy()));
753 // If we're dividing by a positive value, we're done. Otherwise, we must
754 // negate the result.
757 AddToWorkList(SRA.Val);
758 return DAG.getNode(ISD::SUB, VT, DAG.getConstant(0, VT), SRA);
760 // if integer divide is expensive and we satisfy the requirements, emit an
761 // alternate sequence.
762 if (N1C && (N1C->getSignExtended() < -1 || N1C->getSignExtended() > 1) &&
763 !TLI.isIntDivCheap()) {
764 SDOperand Op = BuildSDIV(N);
765 if (Op.Val) return Op;
770 SDOperand DAGCombiner::visitUDIV(SDNode *N) {
771 SDOperand N0 = N->getOperand(0);
772 SDOperand N1 = N->getOperand(1);
773 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.Val);
774 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
775 MVT::ValueType VT = N->getValueType(0);
777 // fold (udiv c1, c2) -> c1/c2
778 if (N0C && N1C && !N1C->isNullValue())
779 return DAG.getNode(ISD::UDIV, VT, N0, N1);
780 // fold (udiv x, (1 << c)) -> x >>u c
781 if (N1C && isPowerOf2_64(N1C->getValue()))
782 return DAG.getNode(ISD::SRL, VT, N0,
783 DAG.getConstant(Log2_64(N1C->getValue()),
784 TLI.getShiftAmountTy()));
785 // fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) iff c is power of 2
786 if (N1.getOpcode() == ISD::SHL) {
787 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
788 if (isPowerOf2_64(SHC->getValue())) {
789 MVT::ValueType ADDVT = N1.getOperand(1).getValueType();
790 SDOperand Add = DAG.getNode(ISD::ADD, ADDVT, N1.getOperand(1),
791 DAG.getConstant(Log2_64(SHC->getValue()),
793 AddToWorkList(Add.Val);
794 return DAG.getNode(ISD::SRL, VT, N0, Add);
798 // fold (udiv x, c) -> alternate
799 if (N1C && N1C->getValue() && !TLI.isIntDivCheap()) {
800 SDOperand Op = BuildUDIV(N);
801 if (Op.Val) return Op;
806 SDOperand DAGCombiner::visitSREM(SDNode *N) {
807 SDOperand N0 = N->getOperand(0);
808 SDOperand N1 = N->getOperand(1);
809 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
810 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
811 MVT::ValueType VT = N->getValueType(0);
813 // fold (srem c1, c2) -> c1%c2
814 if (N0C && N1C && !N1C->isNullValue())
815 return DAG.getNode(ISD::SREM, VT, N0, N1);
816 // If we know the sign bits of both operands are zero, strength reduce to a
817 // urem instead. Handles (X & 0x0FFFFFFF) %s 16 -> X&15
818 uint64_t SignBit = 1ULL << (MVT::getSizeInBits(VT)-1);
819 if (TLI.MaskedValueIsZero(N1, SignBit) &&
820 TLI.MaskedValueIsZero(N0, SignBit))
821 return DAG.getNode(ISD::UREM, VT, N0, N1);
825 SDOperand DAGCombiner::visitUREM(SDNode *N) {
826 SDOperand N0 = N->getOperand(0);
827 SDOperand N1 = N->getOperand(1);
828 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
829 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
830 MVT::ValueType VT = N->getValueType(0);
832 // fold (urem c1, c2) -> c1%c2
833 if (N0C && N1C && !N1C->isNullValue())
834 return DAG.getNode(ISD::UREM, VT, N0, N1);
835 // fold (urem x, pow2) -> (and x, pow2-1)
836 if (N1C && !N1C->isNullValue() && isPowerOf2_64(N1C->getValue()))
837 return DAG.getNode(ISD::AND, VT, N0, DAG.getConstant(N1C->getValue()-1,VT));
838 // fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1))
839 if (N1.getOpcode() == ISD::SHL) {
840 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
841 if (isPowerOf2_64(SHC->getValue())) {
842 SDOperand Add = DAG.getNode(ISD::ADD, VT, N1,DAG.getConstant(~0ULL,VT));
843 AddToWorkList(Add.Val);
844 return DAG.getNode(ISD::AND, VT, N0, Add);
851 SDOperand DAGCombiner::visitMULHS(SDNode *N) {
852 SDOperand N0 = N->getOperand(0);
853 SDOperand N1 = N->getOperand(1);
854 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
856 // fold (mulhs x, 0) -> 0
857 if (N1C && N1C->isNullValue())
859 // fold (mulhs x, 1) -> (sra x, size(x)-1)
860 if (N1C && N1C->getValue() == 1)
861 return DAG.getNode(ISD::SRA, N0.getValueType(), N0,
862 DAG.getConstant(MVT::getSizeInBits(N0.getValueType())-1,
863 TLI.getShiftAmountTy()));
867 SDOperand DAGCombiner::visitMULHU(SDNode *N) {
868 SDOperand N0 = N->getOperand(0);
869 SDOperand N1 = N->getOperand(1);
870 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
872 // fold (mulhu x, 0) -> 0
873 if (N1C && N1C->isNullValue())
875 // fold (mulhu x, 1) -> 0
876 if (N1C && N1C->getValue() == 1)
877 return DAG.getConstant(0, N0.getValueType());
881 /// SimplifyBinOpWithSameOpcodeHands - If this is a binary operator with
882 /// two operands of the same opcode, try to simplify it.
883 SDOperand DAGCombiner::SimplifyBinOpWithSameOpcodeHands(SDNode *N) {
884 SDOperand N0 = N->getOperand(0), N1 = N->getOperand(1);
885 MVT::ValueType VT = N0.getValueType();
886 assert(N0.getOpcode() == N1.getOpcode() && "Bad input!");
888 // For each of OP in AND/OR/XOR:
889 // fold (OP (zext x), (zext y)) -> (zext (OP x, y))
890 // fold (OP (sext x), (sext y)) -> (sext (OP x, y))
891 // fold (OP (aext x), (aext y)) -> (aext (OP x, y))
892 // fold (OP (trunc x), (trunc y)) -> (trunc (OP x, y))
893 if ((N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND||
894 N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::TRUNCATE) &&
895 N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType()) {
896 SDOperand ORNode = DAG.getNode(N->getOpcode(),
897 N0.getOperand(0).getValueType(),
898 N0.getOperand(0), N1.getOperand(0));
899 AddToWorkList(ORNode.Val);
900 return DAG.getNode(N0.getOpcode(), VT, ORNode);
903 // For each of OP in SHL/SRL/SRA/AND...
904 // fold (and (OP x, z), (OP y, z)) -> (OP (and x, y), z)
905 // fold (or (OP x, z), (OP y, z)) -> (OP (or x, y), z)
906 // fold (xor (OP x, z), (OP y, z)) -> (OP (xor x, y), z)
907 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL ||
908 N0.getOpcode() == ISD::SRA || N0.getOpcode() == ISD::AND) &&
909 N0.getOperand(1) == N1.getOperand(1)) {
910 SDOperand ORNode = DAG.getNode(N->getOpcode(),
911 N0.getOperand(0).getValueType(),
912 N0.getOperand(0), N1.getOperand(0));
913 AddToWorkList(ORNode.Val);
914 return DAG.getNode(N0.getOpcode(), VT, ORNode, N0.getOperand(1));
920 SDOperand DAGCombiner::visitAND(SDNode *N) {
921 SDOperand N0 = N->getOperand(0);
922 SDOperand N1 = N->getOperand(1);
923 SDOperand LL, LR, RL, RR, CC0, CC1;
924 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
925 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
926 MVT::ValueType VT = N1.getValueType();
927 unsigned OpSizeInBits = MVT::getSizeInBits(VT);
929 // fold (and c1, c2) -> c1&c2
931 return DAG.getNode(ISD::AND, VT, N0, N1);
932 // canonicalize constant to RHS
934 return DAG.getNode(ISD::AND, VT, N1, N0);
935 // fold (and x, -1) -> x
936 if (N1C && N1C->isAllOnesValue())
938 // if (and x, c) is known to be zero, return 0
939 if (N1C && TLI.MaskedValueIsZero(SDOperand(N, 0), MVT::getIntVTBitMask(VT)))
940 return DAG.getConstant(0, VT);
942 SDOperand RAND = ReassociateOps(ISD::AND, N0, N1);
945 // fold (and (or x, 0xFFFF), 0xFF) -> 0xFF
946 if (N1C && N0.getOpcode() == ISD::OR)
947 if (ConstantSDNode *ORI = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
948 if ((ORI->getValue() & N1C->getValue()) == N1C->getValue())
950 // fold (and (any_ext V), c) -> (zero_ext V) if 'and' only clears top bits.
951 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
952 unsigned InMask = MVT::getIntVTBitMask(N0.getOperand(0).getValueType());
953 if (TLI.MaskedValueIsZero(N0.getOperand(0),
954 ~N1C->getValue() & InMask)) {
955 SDOperand Zext = DAG.getNode(ISD::ZERO_EXTEND, N0.getValueType(),
958 // Replace uses of the AND with uses of the Zero extend node.
961 // We actually want to replace all uses of the any_extend with the
962 // zero_extend, to avoid duplicating things. This will later cause this
964 CombineTo(N0.Val, Zext);
965 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
968 // fold (and (setcc x), (setcc y)) -> (setcc (and x, y))
969 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
970 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
971 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
973 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
974 MVT::isInteger(LL.getValueType())) {
975 // fold (X == 0) & (Y == 0) -> (X|Y == 0)
976 if (cast<ConstantSDNode>(LR)->getValue() == 0 && Op1 == ISD::SETEQ) {
977 SDOperand ORNode = DAG.getNode(ISD::OR, LR.getValueType(), LL, RL);
978 AddToWorkList(ORNode.Val);
979 return DAG.getSetCC(VT, ORNode, LR, Op1);
981 // fold (X == -1) & (Y == -1) -> (X&Y == -1)
982 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETEQ) {
983 SDOperand ANDNode = DAG.getNode(ISD::AND, LR.getValueType(), LL, RL);
984 AddToWorkList(ANDNode.Val);
985 return DAG.getSetCC(VT, ANDNode, LR, Op1);
987 // fold (X > -1) & (Y > -1) -> (X|Y > -1)
988 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETGT) {
989 SDOperand ORNode = DAG.getNode(ISD::OR, LR.getValueType(), LL, RL);
990 AddToWorkList(ORNode.Val);
991 return DAG.getSetCC(VT, ORNode, LR, Op1);
994 // canonicalize equivalent to ll == rl
995 if (LL == RR && LR == RL) {
996 Op1 = ISD::getSetCCSwappedOperands(Op1);
999 if (LL == RL && LR == RR) {
1000 bool isInteger = MVT::isInteger(LL.getValueType());
1001 ISD::CondCode Result = ISD::getSetCCAndOperation(Op0, Op1, isInteger);
1002 if (Result != ISD::SETCC_INVALID)
1003 return DAG.getSetCC(N0.getValueType(), LL, LR, Result);
1007 // Simplify: and (op x...), (op y...) -> (op (and x, y))
1008 if (N0.getOpcode() == N1.getOpcode()) {
1009 SDOperand Tmp = SimplifyBinOpWithSameOpcodeHands(N);
1010 if (Tmp.Val) return Tmp;
1013 // fold (and (sign_extend_inreg x, i16 to i32), 1) -> (and x, 1)
1014 // fold (and (sra)) -> (and (srl)) when possible.
1015 if (!MVT::isVector(VT) &&
1016 SimplifyDemandedBits(SDOperand(N, 0)))
1017 return SDOperand(N, 0);
1018 // fold (zext_inreg (extload x)) -> (zextload x)
1019 if (N0.getOpcode() == ISD::EXTLOAD) {
1020 MVT::ValueType EVT = cast<VTSDNode>(N0.getOperand(3))->getVT();
1021 // If we zero all the possible extended bits, then we can turn this into
1022 // a zextload if we are running before legalize or the operation is legal.
1023 if (TLI.MaskedValueIsZero(N1, ~0ULL << MVT::getSizeInBits(EVT)) &&
1024 (!AfterLegalize || TLI.isOperationLegal(ISD::ZEXTLOAD, EVT))) {
1025 SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, N0.getOperand(0),
1026 N0.getOperand(1), N0.getOperand(2),
1029 CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
1030 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1033 // fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use
1034 if (N0.getOpcode() == ISD::SEXTLOAD && N0.hasOneUse()) {
1035 MVT::ValueType EVT = cast<VTSDNode>(N0.getOperand(3))->getVT();
1036 // If we zero all the possible extended bits, then we can turn this into
1037 // a zextload if we are running before legalize or the operation is legal.
1038 if (TLI.MaskedValueIsZero(N1, ~0ULL << MVT::getSizeInBits(EVT)) &&
1039 (!AfterLegalize || TLI.isOperationLegal(ISD::ZEXTLOAD, EVT))) {
1040 SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, N0.getOperand(0),
1041 N0.getOperand(1), N0.getOperand(2),
1044 CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
1045 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1049 // fold (and (load x), 255) -> (zextload x, i8)
1050 // fold (and (extload x, i16), 255) -> (zextload x, i8)
1052 (N0.getOpcode() == ISD::LOAD || N0.getOpcode() == ISD::EXTLOAD ||
1053 N0.getOpcode() == ISD::ZEXTLOAD) &&
1055 MVT::ValueType EVT, LoadedVT;
1056 if (N1C->getValue() == 255)
1058 else if (N1C->getValue() == 65535)
1060 else if (N1C->getValue() == ~0U)
1065 LoadedVT = N0.getOpcode() == ISD::LOAD ? VT :
1066 cast<VTSDNode>(N0.getOperand(3))->getVT();
1067 if (EVT != MVT::Other && LoadedVT > EVT &&
1068 (!AfterLegalize || TLI.isOperationLegal(ISD::ZEXTLOAD, EVT))) {
1069 MVT::ValueType PtrType = N0.getOperand(1).getValueType();
1070 // For big endian targets, we need to add an offset to the pointer to load
1071 // the correct bytes. For little endian systems, we merely need to read
1072 // fewer bytes from the same pointer.
1074 (MVT::getSizeInBits(LoadedVT) - MVT::getSizeInBits(EVT)) / 8;
1075 SDOperand NewPtr = N0.getOperand(1);
1076 if (!TLI.isLittleEndian())
1077 NewPtr = DAG.getNode(ISD::ADD, PtrType, NewPtr,
1078 DAG.getConstant(PtrOff, PtrType));
1079 AddToWorkList(NewPtr.Val);
1081 DAG.getExtLoad(ISD::ZEXTLOAD, VT, N0.getOperand(0), NewPtr,
1082 N0.getOperand(2), EVT);
1084 CombineTo(N0.Val, Load, Load.getValue(1));
1085 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1092 SDOperand DAGCombiner::visitOR(SDNode *N) {
1093 SDOperand N0 = N->getOperand(0);
1094 SDOperand N1 = N->getOperand(1);
1095 SDOperand LL, LR, RL, RR, CC0, CC1;
1096 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1097 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1098 MVT::ValueType VT = N1.getValueType();
1099 unsigned OpSizeInBits = MVT::getSizeInBits(VT);
1101 // fold (or c1, c2) -> c1|c2
1103 return DAG.getNode(ISD::OR, VT, N0, N1);
1104 // canonicalize constant to RHS
1106 return DAG.getNode(ISD::OR, VT, N1, N0);
1107 // fold (or x, 0) -> x
1108 if (N1C && N1C->isNullValue())
1110 // fold (or x, -1) -> -1
1111 if (N1C && N1C->isAllOnesValue())
1113 // fold (or x, c) -> c iff (x & ~c) == 0
1115 TLI.MaskedValueIsZero(N0,~N1C->getValue() & (~0ULL>>(64-OpSizeInBits))))
1118 SDOperand ROR = ReassociateOps(ISD::OR, N0, N1);
1121 // Canonicalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2)
1122 if (N1C && N0.getOpcode() == ISD::AND && N0.Val->hasOneUse() &&
1123 isa<ConstantSDNode>(N0.getOperand(1))) {
1124 ConstantSDNode *C1 = cast<ConstantSDNode>(N0.getOperand(1));
1125 return DAG.getNode(ISD::AND, VT, DAG.getNode(ISD::OR, VT, N0.getOperand(0),
1127 DAG.getConstant(N1C->getValue() | C1->getValue(), VT));
1129 // fold (or (setcc x), (setcc y)) -> (setcc (or x, y))
1130 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
1131 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
1132 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
1134 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
1135 MVT::isInteger(LL.getValueType())) {
1136 // fold (X != 0) | (Y != 0) -> (X|Y != 0)
1137 // fold (X < 0) | (Y < 0) -> (X|Y < 0)
1138 if (cast<ConstantSDNode>(LR)->getValue() == 0 &&
1139 (Op1 == ISD::SETNE || Op1 == ISD::SETLT)) {
1140 SDOperand ORNode = DAG.getNode(ISD::OR, LR.getValueType(), LL, RL);
1141 AddToWorkList(ORNode.Val);
1142 return DAG.getSetCC(VT, ORNode, LR, Op1);
1144 // fold (X != -1) | (Y != -1) -> (X&Y != -1)
1145 // fold (X > -1) | (Y > -1) -> (X&Y > -1)
1146 if (cast<ConstantSDNode>(LR)->isAllOnesValue() &&
1147 (Op1 == ISD::SETNE || Op1 == ISD::SETGT)) {
1148 SDOperand ANDNode = DAG.getNode(ISD::AND, LR.getValueType(), LL, RL);
1149 AddToWorkList(ANDNode.Val);
1150 return DAG.getSetCC(VT, ANDNode, LR, Op1);
1153 // canonicalize equivalent to ll == rl
1154 if (LL == RR && LR == RL) {
1155 Op1 = ISD::getSetCCSwappedOperands(Op1);
1158 if (LL == RL && LR == RR) {
1159 bool isInteger = MVT::isInteger(LL.getValueType());
1160 ISD::CondCode Result = ISD::getSetCCOrOperation(Op0, Op1, isInteger);
1161 if (Result != ISD::SETCC_INVALID)
1162 return DAG.getSetCC(N0.getValueType(), LL, LR, Result);
1166 // Simplify: or (op x...), (op y...) -> (op (or x, y))
1167 if (N0.getOpcode() == N1.getOpcode()) {
1168 SDOperand Tmp = SimplifyBinOpWithSameOpcodeHands(N);
1169 if (Tmp.Val) return Tmp;
1172 // canonicalize shl to left side in a shl/srl pair, to match rotate
1173 if (N0.getOpcode() == ISD::SRL && N1.getOpcode() == ISD::SHL)
1175 // check for rotl, rotr
1176 if (N0.getOpcode() == ISD::SHL && N1.getOpcode() == ISD::SRL &&
1177 N0.getOperand(0) == N1.getOperand(0) &&
1178 TLI.isOperationLegal(ISD::ROTL, VT) && TLI.isTypeLegal(VT)) {
1179 // fold (or (shl x, C1), (srl x, C2)) -> (rotl x, C1)
1180 if (N0.getOperand(1).getOpcode() == ISD::Constant &&
1181 N1.getOperand(1).getOpcode() == ISD::Constant) {
1182 uint64_t c1val = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
1183 uint64_t c2val = cast<ConstantSDNode>(N1.getOperand(1))->getValue();
1184 if ((c1val + c2val) == OpSizeInBits)
1185 return DAG.getNode(ISD::ROTL, VT, N0.getOperand(0), N0.getOperand(1));
1187 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotl x, y)
1188 if (N1.getOperand(1).getOpcode() == ISD::SUB &&
1189 N0.getOperand(1) == N1.getOperand(1).getOperand(1))
1190 if (ConstantSDNode *SUBC =
1191 dyn_cast<ConstantSDNode>(N1.getOperand(1).getOperand(0)))
1192 if (SUBC->getValue() == OpSizeInBits)
1193 return DAG.getNode(ISD::ROTL, VT, N0.getOperand(0), N0.getOperand(1));
1194 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotr x, y)
1195 if (N0.getOperand(1).getOpcode() == ISD::SUB &&
1196 N1.getOperand(1) == N0.getOperand(1).getOperand(1))
1197 if (ConstantSDNode *SUBC =
1198 dyn_cast<ConstantSDNode>(N0.getOperand(1).getOperand(0)))
1199 if (SUBC->getValue() == OpSizeInBits) {
1200 if (TLI.isOperationLegal(ISD::ROTR, VT) && TLI.isTypeLegal(VT))
1201 return DAG.getNode(ISD::ROTR, VT, N0.getOperand(0),
1204 return DAG.getNode(ISD::ROTL, VT, N0.getOperand(0),
1211 SDOperand DAGCombiner::visitXOR(SDNode *N) {
1212 SDOperand N0 = N->getOperand(0);
1213 SDOperand N1 = N->getOperand(1);
1214 SDOperand LHS, RHS, CC;
1215 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1216 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1217 MVT::ValueType VT = N0.getValueType();
1219 // fold (xor c1, c2) -> c1^c2
1221 return DAG.getNode(ISD::XOR, VT, N0, N1);
1222 // canonicalize constant to RHS
1224 return DAG.getNode(ISD::XOR, VT, N1, N0);
1225 // fold (xor x, 0) -> x
1226 if (N1C && N1C->isNullValue())
1229 SDOperand RXOR = ReassociateOps(ISD::XOR, N0, N1);
1232 // fold !(x cc y) -> (x !cc y)
1233 if (N1C && N1C->getValue() == 1 && isSetCCEquivalent(N0, LHS, RHS, CC)) {
1234 bool isInt = MVT::isInteger(LHS.getValueType());
1235 ISD::CondCode NotCC = ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
1237 if (N0.getOpcode() == ISD::SETCC)
1238 return DAG.getSetCC(VT, LHS, RHS, NotCC);
1239 if (N0.getOpcode() == ISD::SELECT_CC)
1240 return DAG.getSelectCC(LHS, RHS, N0.getOperand(2),N0.getOperand(3),NotCC);
1241 assert(0 && "Unhandled SetCC Equivalent!");
1244 // fold !(x or y) -> (!x and !y) iff x or y are setcc
1245 if (N1C && N1C->getValue() == 1 &&
1246 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
1247 SDOperand LHS = N0.getOperand(0), RHS = N0.getOperand(1);
1248 if (isOneUseSetCC(RHS) || isOneUseSetCC(LHS)) {
1249 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
1250 LHS = DAG.getNode(ISD::XOR, VT, LHS, N1); // RHS = ~LHS
1251 RHS = DAG.getNode(ISD::XOR, VT, RHS, N1); // RHS = ~RHS
1252 AddToWorkList(LHS.Val); AddToWorkList(RHS.Val);
1253 return DAG.getNode(NewOpcode, VT, LHS, RHS);
1256 // fold !(x or y) -> (!x and !y) iff x or y are constants
1257 if (N1C && N1C->isAllOnesValue() &&
1258 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
1259 SDOperand LHS = N0.getOperand(0), RHS = N0.getOperand(1);
1260 if (isa<ConstantSDNode>(RHS) || isa<ConstantSDNode>(LHS)) {
1261 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
1262 LHS = DAG.getNode(ISD::XOR, VT, LHS, N1); // RHS = ~LHS
1263 RHS = DAG.getNode(ISD::XOR, VT, RHS, N1); // RHS = ~RHS
1264 AddToWorkList(LHS.Val); AddToWorkList(RHS.Val);
1265 return DAG.getNode(NewOpcode, VT, LHS, RHS);
1268 // fold (xor (xor x, c1), c2) -> (xor x, c1^c2)
1269 if (N1C && N0.getOpcode() == ISD::XOR) {
1270 ConstantSDNode *N00C = dyn_cast<ConstantSDNode>(N0.getOperand(0));
1271 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
1273 return DAG.getNode(ISD::XOR, VT, N0.getOperand(1),
1274 DAG.getConstant(N1C->getValue()^N00C->getValue(), VT));
1276 return DAG.getNode(ISD::XOR, VT, N0.getOperand(0),
1277 DAG.getConstant(N1C->getValue()^N01C->getValue(), VT));
1279 // fold (xor x, x) -> 0
1281 if (!MVT::isVector(VT)) {
1282 return DAG.getConstant(0, VT);
1283 } else if (!AfterLegalize || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)) {
1284 // Produce a vector of zeros.
1285 SDOperand El = DAG.getConstant(0, MVT::getVectorBaseType(VT));
1286 std::vector<SDOperand> Ops(MVT::getVectorNumElements(VT), El);
1287 return DAG.getNode(ISD::BUILD_VECTOR, VT, Ops);
1291 // Simplify: xor (op x...), (op y...) -> (op (xor x, y))
1292 if (N0.getOpcode() == N1.getOpcode()) {
1293 SDOperand Tmp = SimplifyBinOpWithSameOpcodeHands(N);
1294 if (Tmp.Val) return Tmp;
1297 // Simplify the expression using non-local knowledge.
1298 if (!MVT::isVector(VT) &&
1299 SimplifyDemandedBits(SDOperand(N, 0)))
1300 return SDOperand(N, 0);
1305 SDOperand DAGCombiner::visitSHL(SDNode *N) {
1306 SDOperand N0 = N->getOperand(0);
1307 SDOperand N1 = N->getOperand(1);
1308 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1309 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1310 MVT::ValueType VT = N0.getValueType();
1311 unsigned OpSizeInBits = MVT::getSizeInBits(VT);
1313 // fold (shl c1, c2) -> c1<<c2
1315 return DAG.getNode(ISD::SHL, VT, N0, N1);
1316 // fold (shl 0, x) -> 0
1317 if (N0C && N0C->isNullValue())
1319 // fold (shl x, c >= size(x)) -> undef
1320 if (N1C && N1C->getValue() >= OpSizeInBits)
1321 return DAG.getNode(ISD::UNDEF, VT);
1322 // fold (shl x, 0) -> x
1323 if (N1C && N1C->isNullValue())
1325 // if (shl x, c) is known to be zero, return 0
1326 if (TLI.MaskedValueIsZero(SDOperand(N, 0), MVT::getIntVTBitMask(VT)))
1327 return DAG.getConstant(0, VT);
1328 if (SimplifyDemandedBits(SDOperand(N, 0)))
1329 return SDOperand(N, 0);
1330 // fold (shl (shl x, c1), c2) -> 0 or (shl x, c1+c2)
1331 if (N1C && N0.getOpcode() == ISD::SHL &&
1332 N0.getOperand(1).getOpcode() == ISD::Constant) {
1333 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
1334 uint64_t c2 = N1C->getValue();
1335 if (c1 + c2 > OpSizeInBits)
1336 return DAG.getConstant(0, VT);
1337 return DAG.getNode(ISD::SHL, VT, N0.getOperand(0),
1338 DAG.getConstant(c1 + c2, N1.getValueType()));
1340 // fold (shl (srl x, c1), c2) -> (shl (and x, -1 << c1), c2-c1) or
1341 // (srl (and x, -1 << c1), c1-c2)
1342 if (N1C && N0.getOpcode() == ISD::SRL &&
1343 N0.getOperand(1).getOpcode() == ISD::Constant) {
1344 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
1345 uint64_t c2 = N1C->getValue();
1346 SDOperand Mask = DAG.getNode(ISD::AND, VT, N0.getOperand(0),
1347 DAG.getConstant(~0ULL << c1, VT));
1349 return DAG.getNode(ISD::SHL, VT, Mask,
1350 DAG.getConstant(c2-c1, N1.getValueType()));
1352 return DAG.getNode(ISD::SRL, VT, Mask,
1353 DAG.getConstant(c1-c2, N1.getValueType()));
1355 // fold (shl (sra x, c1), c1) -> (and x, -1 << c1)
1356 if (N1C && N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1))
1357 return DAG.getNode(ISD::AND, VT, N0.getOperand(0),
1358 DAG.getConstant(~0ULL << N1C->getValue(), VT));
1359 // fold (shl (add x, c1), c2) -> (add (shl x, c2), c1<<c2)
1360 if (N1C && N0.getOpcode() == ISD::ADD && N0.Val->hasOneUse() &&
1361 isa<ConstantSDNode>(N0.getOperand(1))) {
1362 return DAG.getNode(ISD::ADD, VT,
1363 DAG.getNode(ISD::SHL, VT, N0.getOperand(0), N1),
1364 DAG.getNode(ISD::SHL, VT, N0.getOperand(1), N1));
1369 SDOperand DAGCombiner::visitSRA(SDNode *N) {
1370 SDOperand N0 = N->getOperand(0);
1371 SDOperand N1 = N->getOperand(1);
1372 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1373 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1374 MVT::ValueType VT = N0.getValueType();
1376 // fold (sra c1, c2) -> c1>>c2
1378 return DAG.getNode(ISD::SRA, VT, N0, N1);
1379 // fold (sra 0, x) -> 0
1380 if (N0C && N0C->isNullValue())
1382 // fold (sra -1, x) -> -1
1383 if (N0C && N0C->isAllOnesValue())
1385 // fold (sra x, c >= size(x)) -> undef
1386 if (N1C && N1C->getValue() >= MVT::getSizeInBits(VT))
1387 return DAG.getNode(ISD::UNDEF, VT);
1388 // fold (sra x, 0) -> x
1389 if (N1C && N1C->isNullValue())
1391 // fold (sra (shl x, c1), c1) -> sext_inreg for some c1 and target supports
1393 if (N1C && N0.getOpcode() == ISD::SHL && N1 == N0.getOperand(1)) {
1394 unsigned LowBits = MVT::getSizeInBits(VT) - (unsigned)N1C->getValue();
1397 default: EVT = MVT::Other; break;
1398 case 1: EVT = MVT::i1; break;
1399 case 8: EVT = MVT::i8; break;
1400 case 16: EVT = MVT::i16; break;
1401 case 32: EVT = MVT::i32; break;
1403 if (EVT > MVT::Other && TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, EVT))
1404 return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, N0.getOperand(0),
1405 DAG.getValueType(EVT));
1408 // fold (sra (sra x, c1), c2) -> (sra x, c1+c2)
1409 if (N1C && N0.getOpcode() == ISD::SRA) {
1410 if (ConstantSDNode *C1 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
1411 unsigned Sum = N1C->getValue() + C1->getValue();
1412 if (Sum >= MVT::getSizeInBits(VT)) Sum = MVT::getSizeInBits(VT)-1;
1413 return DAG.getNode(ISD::SRA, VT, N0.getOperand(0),
1414 DAG.getConstant(Sum, N1C->getValueType(0)));
1418 // Simplify, based on bits shifted out of the LHS.
1419 if (N1C && SimplifyDemandedBits(SDOperand(N, 0)))
1420 return SDOperand(N, 0);
1423 // If the sign bit is known to be zero, switch this to a SRL.
1424 if (TLI.MaskedValueIsZero(N0, MVT::getIntVTSignBit(VT)))
1425 return DAG.getNode(ISD::SRL, VT, N0, N1);
1429 SDOperand DAGCombiner::visitSRL(SDNode *N) {
1430 SDOperand N0 = N->getOperand(0);
1431 SDOperand N1 = N->getOperand(1);
1432 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1433 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1434 MVT::ValueType VT = N0.getValueType();
1435 unsigned OpSizeInBits = MVT::getSizeInBits(VT);
1437 // fold (srl c1, c2) -> c1 >>u c2
1439 return DAG.getNode(ISD::SRL, VT, N0, N1);
1440 // fold (srl 0, x) -> 0
1441 if (N0C && N0C->isNullValue())
1443 // fold (srl x, c >= size(x)) -> undef
1444 if (N1C && N1C->getValue() >= OpSizeInBits)
1445 return DAG.getNode(ISD::UNDEF, VT);
1446 // fold (srl x, 0) -> x
1447 if (N1C && N1C->isNullValue())
1449 // if (srl x, c) is known to be zero, return 0
1450 if (N1C && TLI.MaskedValueIsZero(SDOperand(N, 0), ~0ULL >> (64-OpSizeInBits)))
1451 return DAG.getConstant(0, VT);
1452 // fold (srl (srl x, c1), c2) -> 0 or (srl x, c1+c2)
1453 if (N1C && N0.getOpcode() == ISD::SRL &&
1454 N0.getOperand(1).getOpcode() == ISD::Constant) {
1455 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
1456 uint64_t c2 = N1C->getValue();
1457 if (c1 + c2 > OpSizeInBits)
1458 return DAG.getConstant(0, VT);
1459 return DAG.getNode(ISD::SRL, VT, N0.getOperand(0),
1460 DAG.getConstant(c1 + c2, N1.getValueType()));
1463 // fold (srl (anyextend x), c) -> (anyextend (srl x, c))
1464 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
1465 // Shifting in all undef bits?
1466 MVT::ValueType SmallVT = N0.getOperand(0).getValueType();
1467 if (N1C->getValue() >= MVT::getSizeInBits(SmallVT))
1468 return DAG.getNode(ISD::UNDEF, VT);
1470 SDOperand SmallShift = DAG.getNode(ISD::SRL, SmallVT, N0.getOperand(0), N1);
1471 AddToWorkList(SmallShift.Val);
1472 return DAG.getNode(ISD::ANY_EXTEND, VT, SmallShift);
1475 // fold (srl (ctlz x), "5") -> x iff x has one bit set (the low bit).
1476 if (N1C && N0.getOpcode() == ISD::CTLZ &&
1477 N1C->getValue() == Log2_32(MVT::getSizeInBits(VT))) {
1478 uint64_t KnownZero, KnownOne, Mask = MVT::getIntVTBitMask(VT);
1479 TLI.ComputeMaskedBits(N0.getOperand(0), Mask, KnownZero, KnownOne);
1481 // If any of the input bits are KnownOne, then the input couldn't be all
1482 // zeros, thus the result of the srl will always be zero.
1483 if (KnownOne) return DAG.getConstant(0, VT);
1485 // If all of the bits input the to ctlz node are known to be zero, then
1486 // the result of the ctlz is "32" and the result of the shift is one.
1487 uint64_t UnknownBits = ~KnownZero & Mask;
1488 if (UnknownBits == 0) return DAG.getConstant(1, VT);
1490 // Otherwise, check to see if there is exactly one bit input to the ctlz.
1491 if ((UnknownBits & (UnknownBits-1)) == 0) {
1492 // Okay, we know that only that the single bit specified by UnknownBits
1493 // could be set on input to the CTLZ node. If this bit is set, the SRL
1494 // will return 0, if it is clear, it returns 1. Change the CTLZ/SRL pair
1495 // to an SRL,XOR pair, which is likely to simplify more.
1496 unsigned ShAmt = CountTrailingZeros_64(UnknownBits);
1497 SDOperand Op = N0.getOperand(0);
1499 Op = DAG.getNode(ISD::SRL, VT, Op,
1500 DAG.getConstant(ShAmt, TLI.getShiftAmountTy()));
1501 AddToWorkList(Op.Val);
1503 return DAG.getNode(ISD::XOR, VT, Op, DAG.getConstant(1, VT));
1510 SDOperand DAGCombiner::visitCTLZ(SDNode *N) {
1511 SDOperand N0 = N->getOperand(0);
1512 MVT::ValueType VT = N->getValueType(0);
1514 // fold (ctlz c1) -> c2
1515 if (isa<ConstantSDNode>(N0))
1516 return DAG.getNode(ISD::CTLZ, VT, N0);
1520 SDOperand DAGCombiner::visitCTTZ(SDNode *N) {
1521 SDOperand N0 = N->getOperand(0);
1522 MVT::ValueType VT = N->getValueType(0);
1524 // fold (cttz c1) -> c2
1525 if (isa<ConstantSDNode>(N0))
1526 return DAG.getNode(ISD::CTTZ, VT, N0);
1530 SDOperand DAGCombiner::visitCTPOP(SDNode *N) {
1531 SDOperand N0 = N->getOperand(0);
1532 MVT::ValueType VT = N->getValueType(0);
1534 // fold (ctpop c1) -> c2
1535 if (isa<ConstantSDNode>(N0))
1536 return DAG.getNode(ISD::CTPOP, VT, N0);
1540 SDOperand DAGCombiner::visitSELECT(SDNode *N) {
1541 SDOperand N0 = N->getOperand(0);
1542 SDOperand N1 = N->getOperand(1);
1543 SDOperand N2 = N->getOperand(2);
1544 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1545 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1546 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2);
1547 MVT::ValueType VT = N->getValueType(0);
1549 // fold select C, X, X -> X
1552 // fold select true, X, Y -> X
1553 if (N0C && !N0C->isNullValue())
1555 // fold select false, X, Y -> Y
1556 if (N0C && N0C->isNullValue())
1558 // fold select C, 1, X -> C | X
1559 if (MVT::i1 == VT && N1C && N1C->getValue() == 1)
1560 return DAG.getNode(ISD::OR, VT, N0, N2);
1561 // fold select C, 0, X -> ~C & X
1562 // FIXME: this should check for C type == X type, not i1?
1563 if (MVT::i1 == VT && N1C && N1C->isNullValue()) {
1564 SDOperand XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(1, VT));
1565 AddToWorkList(XORNode.Val);
1566 return DAG.getNode(ISD::AND, VT, XORNode, N2);
1568 // fold select C, X, 1 -> ~C | X
1569 if (MVT::i1 == VT && N2C && N2C->getValue() == 1) {
1570 SDOperand XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(1, VT));
1571 AddToWorkList(XORNode.Val);
1572 return DAG.getNode(ISD::OR, VT, XORNode, N1);
1574 // fold select C, X, 0 -> C & X
1575 // FIXME: this should check for C type == X type, not i1?
1576 if (MVT::i1 == VT && N2C && N2C->isNullValue())
1577 return DAG.getNode(ISD::AND, VT, N0, N1);
1578 // fold X ? X : Y --> X ? 1 : Y --> X | Y
1579 if (MVT::i1 == VT && N0 == N1)
1580 return DAG.getNode(ISD::OR, VT, N0, N2);
1581 // fold X ? Y : X --> X ? Y : 0 --> X & Y
1582 if (MVT::i1 == VT && N0 == N2)
1583 return DAG.getNode(ISD::AND, VT, N0, N1);
1585 // If we can fold this based on the true/false value, do so.
1586 if (SimplifySelectOps(N, N1, N2))
1587 return SDOperand(N, 0); // Don't revisit N.
1589 // fold selects based on a setcc into other things, such as min/max/abs
1590 if (N0.getOpcode() == ISD::SETCC)
1592 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
1593 // having to say they don't support SELECT_CC on every type the DAG knows
1594 // about, since there is no way to mark an opcode illegal at all value types
1595 if (TLI.isOperationLegal(ISD::SELECT_CC, MVT::Other))
1596 return DAG.getNode(ISD::SELECT_CC, VT, N0.getOperand(0), N0.getOperand(1),
1597 N1, N2, N0.getOperand(2));
1599 return SimplifySelect(N0, N1, N2);
1603 SDOperand DAGCombiner::visitSELECT_CC(SDNode *N) {
1604 SDOperand N0 = N->getOperand(0);
1605 SDOperand N1 = N->getOperand(1);
1606 SDOperand N2 = N->getOperand(2);
1607 SDOperand N3 = N->getOperand(3);
1608 SDOperand N4 = N->getOperand(4);
1609 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1610 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1611 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2);
1612 ISD::CondCode CC = cast<CondCodeSDNode>(N4)->get();
1614 // Determine if the condition we're dealing with is constant
1615 SDOperand SCC = SimplifySetCC(TLI.getSetCCResultTy(), N0, N1, CC, false);
1616 //ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.Val);
1618 // fold select_cc lhs, rhs, x, x, cc -> x
1622 // If we can fold this based on the true/false value, do so.
1623 if (SimplifySelectOps(N, N2, N3))
1624 return SDOperand(N, 0); // Don't revisit N.
1626 // fold select_cc into other things, such as min/max/abs
1627 return SimplifySelectCC(N0, N1, N2, N3, CC);
1630 SDOperand DAGCombiner::visitSETCC(SDNode *N) {
1631 return SimplifySetCC(N->getValueType(0), N->getOperand(0), N->getOperand(1),
1632 cast<CondCodeSDNode>(N->getOperand(2))->get());
1635 SDOperand DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
1636 SDOperand N0 = N->getOperand(0);
1637 MVT::ValueType VT = N->getValueType(0);
1639 // fold (sext c1) -> c1
1640 if (ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0))
1641 return DAG.getNode(ISD::SIGN_EXTEND, VT, N0);
1643 // fold (sext (sext x)) -> (sext x)
1644 // fold (sext (aext x)) -> (sext x)
1645 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
1646 return DAG.getNode(ISD::SIGN_EXTEND, VT, N0.getOperand(0));
1648 // fold (sext (truncate x)) -> (sextinreg x) iff x size == sext size.
1649 if (N0.getOpcode() == ISD::TRUNCATE && N0.getOperand(0).getValueType() == VT&&
1651 TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, N0.getValueType())))
1652 return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, N0.getOperand(0),
1653 DAG.getValueType(N0.getValueType()));
1655 // fold (sext (load x)) -> (sext (truncate (sextload x)))
1656 if (N0.getOpcode() == ISD::LOAD && N0.hasOneUse() &&
1657 (!AfterLegalize||TLI.isOperationLegal(ISD::SEXTLOAD, N0.getValueType()))){
1658 SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, N0.getOperand(0),
1659 N0.getOperand(1), N0.getOperand(2),
1661 CombineTo(N, ExtLoad);
1662 CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
1663 ExtLoad.getValue(1));
1664 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1667 // fold (sext (sextload x)) -> (sext (truncate (sextload x)))
1668 // fold (sext ( extload x)) -> (sext (truncate (sextload x)))
1669 if ((N0.getOpcode() == ISD::SEXTLOAD || N0.getOpcode() == ISD::EXTLOAD) &&
1671 MVT::ValueType EVT = cast<VTSDNode>(N0.getOperand(3))->getVT();
1672 SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, N0.getOperand(0),
1673 N0.getOperand(1), N0.getOperand(2), EVT);
1674 CombineTo(N, ExtLoad);
1675 CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
1676 ExtLoad.getValue(1));
1677 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1683 SDOperand DAGCombiner::visitZERO_EXTEND(SDNode *N) {
1684 SDOperand N0 = N->getOperand(0);
1685 MVT::ValueType VT = N->getValueType(0);
1687 // fold (zext c1) -> c1
1688 if (ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0))
1689 return DAG.getNode(ISD::ZERO_EXTEND, VT, N0);
1690 // fold (zext (zext x)) -> (zext x)
1691 // fold (zext (aext x)) -> (zext x)
1692 if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
1693 return DAG.getNode(ISD::ZERO_EXTEND, VT, N0.getOperand(0));
1694 // fold (zext (truncate x)) -> (zextinreg x) iff x size == zext size.
1695 if (N0.getOpcode() == ISD::TRUNCATE && N0.getOperand(0).getValueType() == VT&&
1696 (!AfterLegalize || TLI.isOperationLegal(ISD::AND, N0.getValueType())))
1697 return DAG.getZeroExtendInReg(N0.getOperand(0), N0.getValueType());
1698 // fold (zext (load x)) -> (zext (truncate (zextload x)))
1699 if (N0.getOpcode() == ISD::LOAD && N0.hasOneUse() &&
1700 (!AfterLegalize||TLI.isOperationLegal(ISD::ZEXTLOAD, N0.getValueType()))){
1701 SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, N0.getOperand(0),
1702 N0.getOperand(1), N0.getOperand(2),
1704 CombineTo(N, ExtLoad);
1705 CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
1706 ExtLoad.getValue(1));
1707 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1710 // fold (zext (zextload x)) -> (zext (truncate (zextload x)))
1711 // fold (zext ( extload x)) -> (zext (truncate (zextload x)))
1712 if ((N0.getOpcode() == ISD::ZEXTLOAD || N0.getOpcode() == ISD::EXTLOAD) &&
1714 MVT::ValueType EVT = cast<VTSDNode>(N0.getOperand(3))->getVT();
1715 SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, N0.getOperand(0),
1716 N0.getOperand(1), N0.getOperand(2), EVT);
1717 CombineTo(N, ExtLoad);
1718 CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
1719 ExtLoad.getValue(1));
1720 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1725 SDOperand DAGCombiner::visitANY_EXTEND(SDNode *N) {
1726 SDOperand N0 = N->getOperand(0);
1727 MVT::ValueType VT = N->getValueType(0);
1729 // fold (aext c1) -> c1
1730 if (isa<ConstantSDNode>(N0))
1731 return DAG.getNode(ISD::ANY_EXTEND, VT, N0);
1732 // fold (aext (aext x)) -> (aext x)
1733 // fold (aext (zext x)) -> (zext x)
1734 // fold (aext (sext x)) -> (sext x)
1735 if (N0.getOpcode() == ISD::ANY_EXTEND ||
1736 N0.getOpcode() == ISD::ZERO_EXTEND ||
1737 N0.getOpcode() == ISD::SIGN_EXTEND)
1738 return DAG.getNode(N0.getOpcode(), VT, N0.getOperand(0));
1740 // fold (aext (truncate x)) -> x iff x size == zext size.
1741 if (N0.getOpcode() == ISD::TRUNCATE && N0.getOperand(0).getValueType() == VT)
1742 return N0.getOperand(0);
1743 // fold (aext (load x)) -> (aext (truncate (extload x)))
1744 if (N0.getOpcode() == ISD::LOAD && N0.hasOneUse() &&
1745 (!AfterLegalize||TLI.isOperationLegal(ISD::EXTLOAD, N0.getValueType()))) {
1746 SDOperand ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, VT, N0.getOperand(0),
1747 N0.getOperand(1), N0.getOperand(2),
1749 CombineTo(N, ExtLoad);
1750 CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
1751 ExtLoad.getValue(1));
1752 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1755 // fold (aext (zextload x)) -> (aext (truncate (zextload x)))
1756 // fold (aext (sextload x)) -> (aext (truncate (sextload x)))
1757 // fold (aext ( extload x)) -> (aext (truncate (extload x)))
1758 if ((N0.getOpcode() == ISD::ZEXTLOAD || N0.getOpcode() == ISD::EXTLOAD ||
1759 N0.getOpcode() == ISD::SEXTLOAD) &&
1761 MVT::ValueType EVT = cast<VTSDNode>(N0.getOperand(3))->getVT();
1762 SDOperand ExtLoad = DAG.getExtLoad(N0.getOpcode(), VT, N0.getOperand(0),
1763 N0.getOperand(1), N0.getOperand(2), EVT);
1764 CombineTo(N, ExtLoad);
1765 CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
1766 ExtLoad.getValue(1));
1767 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1773 SDOperand DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
1774 SDOperand N0 = N->getOperand(0);
1775 SDOperand N1 = N->getOperand(1);
1776 MVT::ValueType VT = N->getValueType(0);
1777 MVT::ValueType EVT = cast<VTSDNode>(N1)->getVT();
1778 unsigned EVTBits = MVT::getSizeInBits(EVT);
1780 // fold (sext_in_reg c1) -> c1
1781 if (isa<ConstantSDNode>(N0) || N0.getOpcode() == ISD::UNDEF)
1782 return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, N0, N1);
1784 // If the input is already sign extended, just drop the extension.
1785 if (TLI.ComputeNumSignBits(N0) >= MVT::getSizeInBits(VT)-EVTBits+1)
1788 // fold (sext_in_reg (sext_in_reg x, VT2), VT1) -> (sext_in_reg x, minVT) pt2
1789 if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
1790 EVT < cast<VTSDNode>(N0.getOperand(1))->getVT()) {
1791 return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, N0.getOperand(0), N1);
1794 // fold (sext_in_reg x) -> (zext_in_reg x) if the sign bit is zero
1795 if (TLI.MaskedValueIsZero(N0, 1ULL << (EVTBits-1)))
1796 return DAG.getZeroExtendInReg(N0, EVT);
1798 // fold (sext_in_reg (srl X, 24), i8) -> sra X, 24
1799 // fold (sext_in_reg (srl X, 23), i8) -> sra X, 23 iff possible.
1800 // We already fold "(sext_in_reg (srl X, 25), i8) -> srl X, 25" above.
1801 if (N0.getOpcode() == ISD::SRL) {
1802 if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
1803 if (ShAmt->getValue()+EVTBits <= MVT::getSizeInBits(VT)) {
1804 // We can turn this into an SRA iff the input to the SRL is already sign
1806 unsigned InSignBits = TLI.ComputeNumSignBits(N0.getOperand(0));
1807 if (MVT::getSizeInBits(VT)-(ShAmt->getValue()+EVTBits) < InSignBits)
1808 return DAG.getNode(ISD::SRA, VT, N0.getOperand(0), N0.getOperand(1));
1812 // fold (sext_inreg (extload x)) -> (sextload x)
1813 if (N0.getOpcode() == ISD::EXTLOAD &&
1814 EVT == cast<VTSDNode>(N0.getOperand(3))->getVT() &&
1815 (!AfterLegalize || TLI.isOperationLegal(ISD::SEXTLOAD, EVT))) {
1816 SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, N0.getOperand(0),
1817 N0.getOperand(1), N0.getOperand(2),
1819 CombineTo(N, ExtLoad);
1820 CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
1821 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1823 // fold (sext_inreg (zextload x)) -> (sextload x) iff load has one use
1824 if (N0.getOpcode() == ISD::ZEXTLOAD && N0.hasOneUse() &&
1825 EVT == cast<VTSDNode>(N0.getOperand(3))->getVT() &&
1826 (!AfterLegalize || TLI.isOperationLegal(ISD::SEXTLOAD, EVT))) {
1827 SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, N0.getOperand(0),
1828 N0.getOperand(1), N0.getOperand(2),
1830 CombineTo(N, ExtLoad);
1831 CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
1832 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1837 SDOperand DAGCombiner::visitTRUNCATE(SDNode *N) {
1838 SDOperand N0 = N->getOperand(0);
1839 MVT::ValueType VT = N->getValueType(0);
1842 if (N0.getValueType() == N->getValueType(0))
1844 // fold (truncate c1) -> c1
1845 if (isa<ConstantSDNode>(N0))
1846 return DAG.getNode(ISD::TRUNCATE, VT, N0);
1847 // fold (truncate (truncate x)) -> (truncate x)
1848 if (N0.getOpcode() == ISD::TRUNCATE)
1849 return DAG.getNode(ISD::TRUNCATE, VT, N0.getOperand(0));
1850 // fold (truncate (ext x)) -> (ext x) or (truncate x) or x
1851 if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::SIGN_EXTEND||
1852 N0.getOpcode() == ISD::ANY_EXTEND) {
1853 if (N0.getValueType() < VT)
1854 // if the source is smaller than the dest, we still need an extend
1855 return DAG.getNode(N0.getOpcode(), VT, N0.getOperand(0));
1856 else if (N0.getValueType() > VT)
1857 // if the source is larger than the dest, than we just need the truncate
1858 return DAG.getNode(ISD::TRUNCATE, VT, N0.getOperand(0));
1860 // if the source and dest are the same type, we can drop both the extend
1862 return N0.getOperand(0);
1864 // fold (truncate (load x)) -> (smaller load x)
1865 if (N0.getOpcode() == ISD::LOAD && N0.hasOneUse()) {
1866 assert(MVT::getSizeInBits(N0.getValueType()) > MVT::getSizeInBits(VT) &&
1867 "Cannot truncate to larger type!");
1868 MVT::ValueType PtrType = N0.getOperand(1).getValueType();
1869 // For big endian targets, we need to add an offset to the pointer to load
1870 // the correct bytes. For little endian systems, we merely need to read
1871 // fewer bytes from the same pointer.
1873 (MVT::getSizeInBits(N0.getValueType()) - MVT::getSizeInBits(VT)) / 8;
1874 SDOperand NewPtr = TLI.isLittleEndian() ? N0.getOperand(1) :
1875 DAG.getNode(ISD::ADD, PtrType, N0.getOperand(1),
1876 DAG.getConstant(PtrOff, PtrType));
1877 AddToWorkList(NewPtr.Val);
1878 SDOperand Load = DAG.getLoad(VT, N0.getOperand(0), NewPtr,N0.getOperand(2));
1880 CombineTo(N0.Val, Load, Load.getValue(1));
1881 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1886 SDOperand DAGCombiner::visitBIT_CONVERT(SDNode *N) {
1887 SDOperand N0 = N->getOperand(0);
1888 MVT::ValueType VT = N->getValueType(0);
1890 // If the input is a constant, let getNode() fold it.
1891 if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
1892 SDOperand Res = DAG.getNode(ISD::BIT_CONVERT, VT, N0);
1893 if (Res.Val != N) return Res;
1896 if (N0.getOpcode() == ISD::BIT_CONVERT) // conv(conv(x,t1),t2) -> conv(x,t2)
1897 return DAG.getNode(ISD::BIT_CONVERT, VT, N0.getOperand(0));
1899 // fold (conv (load x)) -> (load (conv*)x)
1900 // FIXME: These xforms need to know that the resultant load doesn't need a
1901 // higher alignment than the original!
1902 if (0 && N0.getOpcode() == ISD::LOAD && N0.hasOneUse()) {
1903 SDOperand Load = DAG.getLoad(VT, N0.getOperand(0), N0.getOperand(1),
1906 CombineTo(N0.Val, DAG.getNode(ISD::BIT_CONVERT, N0.getValueType(), Load),
1914 SDOperand DAGCombiner::visitVBIT_CONVERT(SDNode *N) {
1915 SDOperand N0 = N->getOperand(0);
1916 MVT::ValueType VT = N->getValueType(0);
1918 // If the input is a VBUILD_VECTOR with all constant elements, fold this now.
1919 // First check to see if this is all constant.
1920 if (N0.getOpcode() == ISD::VBUILD_VECTOR && N0.Val->hasOneUse() &&
1921 VT == MVT::Vector) {
1922 bool isSimple = true;
1923 for (unsigned i = 0, e = N0.getNumOperands()-2; i != e; ++i)
1924 if (N0.getOperand(i).getOpcode() != ISD::UNDEF &&
1925 N0.getOperand(i).getOpcode() != ISD::Constant &&
1926 N0.getOperand(i).getOpcode() != ISD::ConstantFP) {
1931 MVT::ValueType DestEltVT = cast<VTSDNode>(N->getOperand(2))->getVT();
1932 if (isSimple && !MVT::isVector(DestEltVT)) {
1933 return ConstantFoldVBIT_CONVERTofVBUILD_VECTOR(N0.Val, DestEltVT);
1940 /// ConstantFoldVBIT_CONVERTofVBUILD_VECTOR - We know that BV is a vbuild_vector
1941 /// node with Constant, ConstantFP or Undef operands. DstEltVT indicates the
1942 /// destination element value type.
1943 SDOperand DAGCombiner::
1944 ConstantFoldVBIT_CONVERTofVBUILD_VECTOR(SDNode *BV, MVT::ValueType DstEltVT) {
1945 MVT::ValueType SrcEltVT = BV->getOperand(0).getValueType();
1947 // If this is already the right type, we're done.
1948 if (SrcEltVT == DstEltVT) return SDOperand(BV, 0);
1950 unsigned SrcBitSize = MVT::getSizeInBits(SrcEltVT);
1951 unsigned DstBitSize = MVT::getSizeInBits(DstEltVT);
1953 // If this is a conversion of N elements of one type to N elements of another
1954 // type, convert each element. This handles FP<->INT cases.
1955 if (SrcBitSize == DstBitSize) {
1956 std::vector<SDOperand> Ops;
1957 for (unsigned i = 0, e = BV->getNumOperands()-2; i != e; ++i) {
1958 Ops.push_back(DAG.getNode(ISD::BIT_CONVERT, DstEltVT, BV->getOperand(i)));
1959 AddToWorkList(Ops.back().Val);
1961 Ops.push_back(*(BV->op_end()-2)); // Add num elements.
1962 Ops.push_back(DAG.getValueType(DstEltVT));
1963 return DAG.getNode(ISD::VBUILD_VECTOR, MVT::Vector, Ops);
1966 // Otherwise, we're growing or shrinking the elements. To avoid having to
1967 // handle annoying details of growing/shrinking FP values, we convert them to
1969 if (MVT::isFloatingPoint(SrcEltVT)) {
1970 // Convert the input float vector to a int vector where the elements are the
1972 assert((SrcEltVT == MVT::f32 || SrcEltVT == MVT::f64) && "Unknown FP VT!");
1973 MVT::ValueType IntVT = SrcEltVT == MVT::f32 ? MVT::i32 : MVT::i64;
1974 BV = ConstantFoldVBIT_CONVERTofVBUILD_VECTOR(BV, IntVT).Val;
1978 // Now we know the input is an integer vector. If the output is a FP type,
1979 // convert to integer first, then to FP of the right size.
1980 if (MVT::isFloatingPoint(DstEltVT)) {
1981 assert((DstEltVT == MVT::f32 || DstEltVT == MVT::f64) && "Unknown FP VT!");
1982 MVT::ValueType TmpVT = DstEltVT == MVT::f32 ? MVT::i32 : MVT::i64;
1983 SDNode *Tmp = ConstantFoldVBIT_CONVERTofVBUILD_VECTOR(BV, TmpVT).Val;
1985 // Next, convert to FP elements of the same size.
1986 return ConstantFoldVBIT_CONVERTofVBUILD_VECTOR(Tmp, DstEltVT);
1989 // Okay, we know the src/dst types are both integers of differing types.
1990 // Handling growing first.
1991 assert(MVT::isInteger(SrcEltVT) && MVT::isInteger(DstEltVT));
1992 if (SrcBitSize < DstBitSize) {
1993 unsigned NumInputsPerOutput = DstBitSize/SrcBitSize;
1995 std::vector<SDOperand> Ops;
1996 for (unsigned i = 0, e = BV->getNumOperands()-2; i != e;
1997 i += NumInputsPerOutput) {
1998 bool isLE = TLI.isLittleEndian();
1999 uint64_t NewBits = 0;
2000 bool EltIsUndef = true;
2001 for (unsigned j = 0; j != NumInputsPerOutput; ++j) {
2002 // Shift the previously computed bits over.
2003 NewBits <<= SrcBitSize;
2004 SDOperand Op = BV->getOperand(i+ (isLE ? (NumInputsPerOutput-j-1) : j));
2005 if (Op.getOpcode() == ISD::UNDEF) continue;
2008 NewBits |= cast<ConstantSDNode>(Op)->getValue();
2012 Ops.push_back(DAG.getNode(ISD::UNDEF, DstEltVT));
2014 Ops.push_back(DAG.getConstant(NewBits, DstEltVT));
2017 Ops.push_back(DAG.getConstant(Ops.size(), MVT::i32)); // Add num elements.
2018 Ops.push_back(DAG.getValueType(DstEltVT)); // Add element size.
2019 return DAG.getNode(ISD::VBUILD_VECTOR, MVT::Vector, Ops);
2022 // Finally, this must be the case where we are shrinking elements: each input
2023 // turns into multiple outputs.
2024 unsigned NumOutputsPerInput = SrcBitSize/DstBitSize;
2025 std::vector<SDOperand> Ops;
2026 for (unsigned i = 0, e = BV->getNumOperands()-2; i != e; ++i) {
2027 if (BV->getOperand(i).getOpcode() == ISD::UNDEF) {
2028 for (unsigned j = 0; j != NumOutputsPerInput; ++j)
2029 Ops.push_back(DAG.getNode(ISD::UNDEF, DstEltVT));
2032 uint64_t OpVal = cast<ConstantSDNode>(BV->getOperand(i))->getValue();
2034 for (unsigned j = 0; j != NumOutputsPerInput; ++j) {
2035 unsigned ThisVal = OpVal & ((1ULL << DstBitSize)-1);
2036 OpVal >>= DstBitSize;
2037 Ops.push_back(DAG.getConstant(ThisVal, DstEltVT));
2040 // For big endian targets, swap the order of the pieces of each element.
2041 if (!TLI.isLittleEndian())
2042 std::reverse(Ops.end()-NumOutputsPerInput, Ops.end());
2044 Ops.push_back(DAG.getConstant(Ops.size(), MVT::i32)); // Add num elements.
2045 Ops.push_back(DAG.getValueType(DstEltVT)); // Add element size.
2046 return DAG.getNode(ISD::VBUILD_VECTOR, MVT::Vector, Ops);
2051 SDOperand DAGCombiner::visitFADD(SDNode *N) {
2052 SDOperand N0 = N->getOperand(0);
2053 SDOperand N1 = N->getOperand(1);
2054 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
2055 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
2056 MVT::ValueType VT = N->getValueType(0);
2058 // fold (fadd c1, c2) -> c1+c2
2060 return DAG.getNode(ISD::FADD, VT, N0, N1);
2061 // canonicalize constant to RHS
2062 if (N0CFP && !N1CFP)
2063 return DAG.getNode(ISD::FADD, VT, N1, N0);
2064 // fold (A + (-B)) -> A-B
2065 if (N1.getOpcode() == ISD::FNEG)
2066 return DAG.getNode(ISD::FSUB, VT, N0, N1.getOperand(0));
2067 // fold ((-A) + B) -> B-A
2068 if (N0.getOpcode() == ISD::FNEG)
2069 return DAG.getNode(ISD::FSUB, VT, N1, N0.getOperand(0));
2073 SDOperand DAGCombiner::visitFSUB(SDNode *N) {
2074 SDOperand N0 = N->getOperand(0);
2075 SDOperand N1 = N->getOperand(1);
2076 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
2077 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
2078 MVT::ValueType VT = N->getValueType(0);
2080 // fold (fsub c1, c2) -> c1-c2
2082 return DAG.getNode(ISD::FSUB, VT, N0, N1);
2083 // fold (A-(-B)) -> A+B
2084 if (N1.getOpcode() == ISD::FNEG)
2085 return DAG.getNode(ISD::FADD, VT, N0, N1.getOperand(0));
2089 SDOperand DAGCombiner::visitFMUL(SDNode *N) {
2090 SDOperand N0 = N->getOperand(0);
2091 SDOperand N1 = N->getOperand(1);
2092 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
2093 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
2094 MVT::ValueType VT = N->getValueType(0);
2096 // fold (fmul c1, c2) -> c1*c2
2098 return DAG.getNode(ISD::FMUL, VT, N0, N1);
2099 // canonicalize constant to RHS
2100 if (N0CFP && !N1CFP)
2101 return DAG.getNode(ISD::FMUL, VT, N1, N0);
2102 // fold (fmul X, 2.0) -> (fadd X, X)
2103 if (N1CFP && N1CFP->isExactlyValue(+2.0))
2104 return DAG.getNode(ISD::FADD, VT, N0, N0);
2108 SDOperand DAGCombiner::visitFDIV(SDNode *N) {
2109 SDOperand N0 = N->getOperand(0);
2110 SDOperand N1 = N->getOperand(1);
2111 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
2112 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
2113 MVT::ValueType VT = N->getValueType(0);
2115 // fold (fdiv c1, c2) -> c1/c2
2117 return DAG.getNode(ISD::FDIV, VT, N0, N1);
2121 SDOperand DAGCombiner::visitFREM(SDNode *N) {
2122 SDOperand N0 = N->getOperand(0);
2123 SDOperand N1 = N->getOperand(1);
2124 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
2125 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
2126 MVT::ValueType VT = N->getValueType(0);
2128 // fold (frem c1, c2) -> fmod(c1,c2)
2130 return DAG.getNode(ISD::FREM, VT, N0, N1);
2134 SDOperand DAGCombiner::visitFCOPYSIGN(SDNode *N) {
2135 SDOperand N0 = N->getOperand(0);
2136 SDOperand N1 = N->getOperand(1);
2137 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
2138 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
2139 MVT::ValueType VT = N->getValueType(0);
2141 if (N0CFP && N1CFP) // Constant fold
2142 return DAG.getNode(ISD::FCOPYSIGN, VT, N0, N1);
2145 // copysign(x, c1) -> fabs(x) iff ispos(c1)
2146 // copysign(x, c1) -> fneg(fabs(x)) iff isneg(c1)
2151 u.d = N1CFP->getValue();
2153 return DAG.getNode(ISD::FABS, VT, N0);
2155 return DAG.getNode(ISD::FNEG, VT, DAG.getNode(ISD::FABS, VT, N0));
2158 // copysign(fabs(x), y) -> copysign(x, y)
2159 // copysign(fneg(x), y) -> copysign(x, y)
2160 // copysign(copysign(x,z), y) -> copysign(x, y)
2161 if (N0.getOpcode() == ISD::FABS || N0.getOpcode() == ISD::FNEG ||
2162 N0.getOpcode() == ISD::FCOPYSIGN)
2163 return DAG.getNode(ISD::FCOPYSIGN, VT, N0.getOperand(0), N1);
2165 // copysign(x, abs(y)) -> abs(x)
2166 if (N1.getOpcode() == ISD::FABS)
2167 return DAG.getNode(ISD::FABS, VT, N0);
2169 // copysign(x, copysign(y,z)) -> copysign(x, z)
2170 if (N1.getOpcode() == ISD::FCOPYSIGN)
2171 return DAG.getNode(ISD::FCOPYSIGN, VT, N0, N1.getOperand(1));
2173 // copysign(x, fp_extend(y)) -> copysign(x, y)
2174 // copysign(x, fp_round(y)) -> copysign(x, y)
2175 if (N1.getOpcode() == ISD::FP_EXTEND || N1.getOpcode() == ISD::FP_ROUND)
2176 return DAG.getNode(ISD::FCOPYSIGN, VT, N0, N1.getOperand(0));
2183 SDOperand DAGCombiner::visitSINT_TO_FP(SDNode *N) {
2184 SDOperand N0 = N->getOperand(0);
2185 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2186 MVT::ValueType VT = N->getValueType(0);
2188 // fold (sint_to_fp c1) -> c1fp
2190 return DAG.getNode(ISD::SINT_TO_FP, VT, N0);
2194 SDOperand DAGCombiner::visitUINT_TO_FP(SDNode *N) {
2195 SDOperand N0 = N->getOperand(0);
2196 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2197 MVT::ValueType VT = N->getValueType(0);
2199 // fold (uint_to_fp c1) -> c1fp
2201 return DAG.getNode(ISD::UINT_TO_FP, VT, N0);
2205 SDOperand DAGCombiner::visitFP_TO_SINT(SDNode *N) {
2206 SDOperand N0 = N->getOperand(0);
2207 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
2208 MVT::ValueType VT = N->getValueType(0);
2210 // fold (fp_to_sint c1fp) -> c1
2212 return DAG.getNode(ISD::FP_TO_SINT, VT, N0);
2216 SDOperand DAGCombiner::visitFP_TO_UINT(SDNode *N) {
2217 SDOperand N0 = N->getOperand(0);
2218 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
2219 MVT::ValueType VT = N->getValueType(0);
2221 // fold (fp_to_uint c1fp) -> c1
2223 return DAG.getNode(ISD::FP_TO_UINT, VT, N0);
2227 SDOperand DAGCombiner::visitFP_ROUND(SDNode *N) {
2228 SDOperand N0 = N->getOperand(0);
2229 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
2230 MVT::ValueType VT = N->getValueType(0);
2232 // fold (fp_round c1fp) -> c1fp
2234 return DAG.getNode(ISD::FP_ROUND, VT, N0);
2236 // fold (fp_round (fp_extend x)) -> x
2237 if (N0.getOpcode() == ISD::FP_EXTEND && VT == N0.getOperand(0).getValueType())
2238 return N0.getOperand(0);
2240 // fold (fp_round (copysign X, Y)) -> (copysign (fp_round X), Y)
2241 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.Val->hasOneUse()) {
2242 SDOperand Tmp = DAG.getNode(ISD::FP_ROUND, VT, N0.getOperand(0));
2243 AddToWorkList(Tmp.Val);
2244 return DAG.getNode(ISD::FCOPYSIGN, VT, Tmp, N0.getOperand(1));
2250 SDOperand DAGCombiner::visitFP_ROUND_INREG(SDNode *N) {
2251 SDOperand N0 = N->getOperand(0);
2252 MVT::ValueType VT = N->getValueType(0);
2253 MVT::ValueType EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
2254 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
2256 // fold (fp_round_inreg c1fp) -> c1fp
2258 SDOperand Round = DAG.getConstantFP(N0CFP->getValue(), EVT);
2259 return DAG.getNode(ISD::FP_EXTEND, VT, Round);
2264 SDOperand DAGCombiner::visitFP_EXTEND(SDNode *N) {
2265 SDOperand N0 = N->getOperand(0);
2266 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
2267 MVT::ValueType VT = N->getValueType(0);
2269 // fold (fp_extend c1fp) -> c1fp
2271 return DAG.getNode(ISD::FP_EXTEND, VT, N0);
2273 // fold (fpext (load x)) -> (fpext (fpround (extload x)))
2274 if (N0.getOpcode() == ISD::LOAD && N0.hasOneUse() &&
2275 (!AfterLegalize||TLI.isOperationLegal(ISD::EXTLOAD, N0.getValueType()))) {
2276 SDOperand ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, VT, N0.getOperand(0),
2277 N0.getOperand(1), N0.getOperand(2),
2279 CombineTo(N, ExtLoad);
2280 CombineTo(N0.Val, DAG.getNode(ISD::FP_ROUND, N0.getValueType(), ExtLoad),
2281 ExtLoad.getValue(1));
2282 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
2289 SDOperand DAGCombiner::visitFNEG(SDNode *N) {
2290 SDOperand N0 = N->getOperand(0);
2291 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
2292 MVT::ValueType VT = N->getValueType(0);
2294 // fold (fneg c1) -> -c1
2296 return DAG.getNode(ISD::FNEG, VT, N0);
2297 // fold (fneg (sub x, y)) -> (sub y, x)
2298 if (N0.getOpcode() == ISD::SUB)
2299 return DAG.getNode(ISD::SUB, VT, N0.getOperand(1), N0.getOperand(0));
2300 // fold (fneg (fneg x)) -> x
2301 if (N0.getOpcode() == ISD::FNEG)
2302 return N0.getOperand(0);
2306 SDOperand DAGCombiner::visitFABS(SDNode *N) {
2307 SDOperand N0 = N->getOperand(0);
2308 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
2309 MVT::ValueType VT = N->getValueType(0);
2311 // fold (fabs c1) -> fabs(c1)
2313 return DAG.getNode(ISD::FABS, VT, N0);
2314 // fold (fabs (fabs x)) -> (fabs x)
2315 if (N0.getOpcode() == ISD::FABS)
2316 return N->getOperand(0);
2317 // fold (fabs (fneg x)) -> (fabs x)
2318 // fold (fabs (fcopysign x, y)) -> (fabs x)
2319 if (N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FCOPYSIGN)
2320 return DAG.getNode(ISD::FABS, VT, N0.getOperand(0));
2325 SDOperand DAGCombiner::visitBRCOND(SDNode *N) {
2326 SDOperand Chain = N->getOperand(0);
2327 SDOperand N1 = N->getOperand(1);
2328 SDOperand N2 = N->getOperand(2);
2329 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2331 // never taken branch, fold to chain
2332 if (N1C && N1C->isNullValue())
2334 // unconditional branch
2335 if (N1C && N1C->getValue() == 1)
2336 return DAG.getNode(ISD::BR, MVT::Other, Chain, N2);
2337 // fold a brcond with a setcc condition into a BR_CC node if BR_CC is legal
2339 if (N1.getOpcode() == ISD::SETCC &&
2340 TLI.isOperationLegal(ISD::BR_CC, MVT::Other)) {
2341 return DAG.getNode(ISD::BR_CC, MVT::Other, Chain, N1.getOperand(2),
2342 N1.getOperand(0), N1.getOperand(1), N2);
2347 // Operand List for BR_CC: Chain, CondCC, CondLHS, CondRHS, DestBB.
2349 SDOperand DAGCombiner::visitBR_CC(SDNode *N) {
2350 CondCodeSDNode *CC = cast<CondCodeSDNode>(N->getOperand(1));
2351 SDOperand CondLHS = N->getOperand(2), CondRHS = N->getOperand(3);
2353 // Use SimplifySetCC to simplify SETCC's.
2354 SDOperand Simp = SimplifySetCC(MVT::i1, CondLHS, CondRHS, CC->get(), false);
2355 ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(Simp.Val);
2357 // fold br_cc true, dest -> br dest (unconditional branch)
2358 if (SCCC && SCCC->getValue())
2359 return DAG.getNode(ISD::BR, MVT::Other, N->getOperand(0),
2361 // fold br_cc false, dest -> unconditional fall through
2362 if (SCCC && SCCC->isNullValue())
2363 return N->getOperand(0);
2364 // fold to a simpler setcc
2365 if (Simp.Val && Simp.getOpcode() == ISD::SETCC)
2366 return DAG.getNode(ISD::BR_CC, MVT::Other, N->getOperand(0),
2367 Simp.getOperand(2), Simp.getOperand(0),
2368 Simp.getOperand(1), N->getOperand(4));
2372 SDOperand DAGCombiner::visitLOAD(SDNode *N) {
2373 SDOperand Chain = N->getOperand(0);
2374 SDOperand Ptr = N->getOperand(1);
2375 SDOperand SrcValue = N->getOperand(2);
2377 // If there are no uses of the loaded value, change uses of the chain value
2378 // into uses of the chain input (i.e. delete the dead load).
2379 if (N->hasNUsesOfValue(0, 0))
2380 return CombineTo(N, DAG.getNode(ISD::UNDEF, N->getValueType(0)), Chain);
2382 // If this load is directly stored, replace the load value with the stored
2384 // TODO: Handle store large -> read small portion.
2385 // TODO: Handle TRUNCSTORE/EXTLOAD
2386 if (Chain.getOpcode() == ISD::STORE && Chain.getOperand(2) == Ptr &&
2387 Chain.getOperand(1).getValueType() == N->getValueType(0))
2388 return CombineTo(N, Chain.getOperand(1), Chain);
2393 /// visitXEXTLOAD - Handle EXTLOAD/ZEXTLOAD/SEXTLOAD.
2394 SDOperand DAGCombiner::visitXEXTLOAD(SDNode *N) {
2395 SDOperand Chain = N->getOperand(0);
2396 SDOperand Ptr = N->getOperand(1);
2397 SDOperand SrcValue = N->getOperand(2);
2398 SDOperand EVT = N->getOperand(3);
2400 // If there are no uses of the loaded value, change uses of the chain value
2401 // into uses of the chain input (i.e. delete the dead load).
2402 if (N->hasNUsesOfValue(0, 0))
2403 return CombineTo(N, DAG.getNode(ISD::UNDEF, N->getValueType(0)), Chain);
2408 SDOperand DAGCombiner::visitSTORE(SDNode *N) {
2409 SDOperand Chain = N->getOperand(0);
2410 SDOperand Value = N->getOperand(1);
2411 SDOperand Ptr = N->getOperand(2);
2412 SDOperand SrcValue = N->getOperand(3);
2414 // If this is a store that kills a previous store, remove the previous store.
2415 if (Chain.getOpcode() == ISD::STORE && Chain.getOperand(2) == Ptr &&
2416 Chain.Val->hasOneUse() /* Avoid introducing DAG cycles */ &&
2417 // Make sure that these stores are the same value type:
2418 // FIXME: we really care that the second store is >= size of the first.
2419 Value.getValueType() == Chain.getOperand(1).getValueType()) {
2420 // Create a new store of Value that replaces both stores.
2421 SDNode *PrevStore = Chain.Val;
2422 if (PrevStore->getOperand(1) == Value) // Same value multiply stored.
2424 SDOperand NewStore = DAG.getNode(ISD::STORE, MVT::Other,
2425 PrevStore->getOperand(0), Value, Ptr,
2427 CombineTo(N, NewStore); // Nuke this store.
2428 CombineTo(PrevStore, NewStore); // Nuke the previous store.
2429 return SDOperand(N, 0);
2432 // If this is a store of a bit convert, store the input value.
2433 // FIXME: This needs to know that the resultant store does not need a
2434 // higher alignment than the original.
2435 if (0 && Value.getOpcode() == ISD::BIT_CONVERT)
2436 return DAG.getNode(ISD::STORE, MVT::Other, Chain, Value.getOperand(0),
2442 SDOperand DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) {
2443 SDOperand InVec = N->getOperand(0);
2444 SDOperand InVal = N->getOperand(1);
2445 SDOperand EltNo = N->getOperand(2);
2447 // If the invec is a BUILD_VECTOR and if EltNo is a constant, build a new
2448 // vector with the inserted element.
2449 if (InVec.getOpcode() == ISD::BUILD_VECTOR && isa<ConstantSDNode>(EltNo)) {
2450 unsigned Elt = cast<ConstantSDNode>(EltNo)->getValue();
2451 std::vector<SDOperand> Ops(InVec.Val->op_begin(), InVec.Val->op_end());
2452 if (Elt < Ops.size())
2454 return DAG.getNode(ISD::BUILD_VECTOR, InVec.getValueType(), Ops);
2460 SDOperand DAGCombiner::visitVINSERT_VECTOR_ELT(SDNode *N) {
2461 SDOperand InVec = N->getOperand(0);
2462 SDOperand InVal = N->getOperand(1);
2463 SDOperand EltNo = N->getOperand(2);
2464 SDOperand NumElts = N->getOperand(3);
2465 SDOperand EltType = N->getOperand(4);
2467 // If the invec is a VBUILD_VECTOR and if EltNo is a constant, build a new
2468 // vector with the inserted element.
2469 if (InVec.getOpcode() == ISD::VBUILD_VECTOR && isa<ConstantSDNode>(EltNo)) {
2470 unsigned Elt = cast<ConstantSDNode>(EltNo)->getValue();
2471 std::vector<SDOperand> Ops(InVec.Val->op_begin(), InVec.Val->op_end());
2472 if (Elt < Ops.size()-2)
2474 return DAG.getNode(ISD::VBUILD_VECTOR, InVec.getValueType(), Ops);
2480 SDOperand DAGCombiner::visitVBUILD_VECTOR(SDNode *N) {
2481 unsigned NumInScalars = N->getNumOperands()-2;
2482 SDOperand NumElts = N->getOperand(NumInScalars);
2483 SDOperand EltType = N->getOperand(NumInScalars+1);
2485 // Check to see if this is a VBUILD_VECTOR of a bunch of VEXTRACT_VECTOR_ELT
2486 // operations. If so, and if the EXTRACT_ELT vector inputs come from at most
2487 // two distinct vectors, turn this into a shuffle node.
2488 SDOperand VecIn1, VecIn2;
2489 for (unsigned i = 0; i != NumInScalars; ++i) {
2490 // Ignore undef inputs.
2491 if (N->getOperand(i).getOpcode() == ISD::UNDEF) continue;
2493 // If this input is something other than a VEXTRACT_VECTOR_ELT with a
2494 // constant index, bail out.
2495 if (N->getOperand(i).getOpcode() != ISD::VEXTRACT_VECTOR_ELT ||
2496 !isa<ConstantSDNode>(N->getOperand(i).getOperand(1))) {
2497 VecIn1 = VecIn2 = SDOperand(0, 0);
2501 // If the input vector type disagrees with the result of the vbuild_vector,
2502 // we can't make a shuffle.
2503 SDOperand ExtractedFromVec = N->getOperand(i).getOperand(0);
2504 if (*(ExtractedFromVec.Val->op_end()-2) != NumElts ||
2505 *(ExtractedFromVec.Val->op_end()-1) != EltType) {
2506 VecIn1 = VecIn2 = SDOperand(0, 0);
2510 // Otherwise, remember this. We allow up to two distinct input vectors.
2511 if (ExtractedFromVec == VecIn1 || ExtractedFromVec == VecIn2)
2514 if (VecIn1.Val == 0) {
2515 VecIn1 = ExtractedFromVec;
2516 } else if (VecIn2.Val == 0) {
2517 VecIn2 = ExtractedFromVec;
2520 VecIn1 = VecIn2 = SDOperand(0, 0);
2525 // If everything is good, we can make a shuffle operation.
2527 std::vector<SDOperand> BuildVecIndices;
2528 for (unsigned i = 0; i != NumInScalars; ++i) {
2529 if (N->getOperand(i).getOpcode() == ISD::UNDEF) {
2530 BuildVecIndices.push_back(DAG.getNode(ISD::UNDEF, MVT::i32));
2534 SDOperand Extract = N->getOperand(i);
2536 // If extracting from the first vector, just use the index directly.
2537 if (Extract.getOperand(0) == VecIn1) {
2538 BuildVecIndices.push_back(Extract.getOperand(1));
2542 // Otherwise, use InIdx + VecSize
2543 unsigned Idx = cast<ConstantSDNode>(Extract.getOperand(1))->getValue();
2544 BuildVecIndices.push_back(DAG.getConstant(Idx+NumInScalars, MVT::i32));
2547 // Add count and size info.
2548 BuildVecIndices.push_back(NumElts);
2549 BuildVecIndices.push_back(DAG.getValueType(MVT::i32));
2551 // Return the new VVECTOR_SHUFFLE node.
2552 std::vector<SDOperand> Ops;
2553 Ops.push_back(VecIn1);
2555 Ops.push_back(VecIn2);
2557 // Use an undef vbuild_vector as input for the second operand.
2558 std::vector<SDOperand> UnOps(NumInScalars,
2559 DAG.getNode(ISD::UNDEF,
2560 cast<VTSDNode>(EltType)->getVT()));
2561 UnOps.push_back(NumElts);
2562 UnOps.push_back(EltType);
2563 Ops.push_back(DAG.getNode(ISD::VBUILD_VECTOR, MVT::Vector, UnOps));
2564 AddToWorkList(Ops.back().Val);
2566 Ops.push_back(DAG.getNode(ISD::VBUILD_VECTOR,MVT::Vector, BuildVecIndices));
2567 Ops.push_back(NumElts);
2568 Ops.push_back(EltType);
2569 return DAG.getNode(ISD::VVECTOR_SHUFFLE, MVT::Vector, Ops);
2575 SDOperand DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
2576 SDOperand ShufMask = N->getOperand(2);
2577 unsigned NumElts = ShufMask.getNumOperands();
2579 // If the shuffle mask is an identity operation on the LHS, return the LHS.
2580 bool isIdentity = true;
2581 for (unsigned i = 0; i != NumElts; ++i) {
2582 if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF &&
2583 cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() != i) {
2588 if (isIdentity) return N->getOperand(0);
2590 // If the shuffle mask is an identity operation on the RHS, return the RHS.
2592 for (unsigned i = 0; i != NumElts; ++i) {
2593 if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF &&
2594 cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() != i+NumElts) {
2599 if (isIdentity) return N->getOperand(1);
2601 // Check if the shuffle is a unary shuffle, i.e. one of the vectors is not
2603 bool isUnary = true;
2604 bool isSplat = true;
2606 unsigned BaseIdx = 0;
2607 for (unsigned i = 0; i != NumElts; ++i)
2608 if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF) {
2609 unsigned Idx = cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue();
2610 int V = (Idx < NumElts) ? 0 : 1;
2624 SDOperand N0 = N->getOperand(0);
2625 SDOperand N1 = N->getOperand(1);
2626 // Normalize unary shuffle so the RHS is undef.
2627 if (isUnary && VecNum == 1)
2630 // If it is a splat, check if the argument vector is a build_vector with
2631 // all scalar elements the same.
2634 if (V->getOpcode() == ISD::BIT_CONVERT)
2635 V = V->getOperand(0).Val;
2636 if (V->getOpcode() == ISD::BUILD_VECTOR) {
2637 unsigned NumElems = V->getNumOperands()-2;
2638 if (NumElems > BaseIdx) {
2640 bool AllSame = true;
2641 for (unsigned i = 0; i != NumElems; ++i) {
2642 if (V->getOperand(i).getOpcode() != ISD::UNDEF) {
2643 Base = V->getOperand(i);
2647 // Splat of <u, u, u, u>, return <u, u, u, u>
2650 for (unsigned i = 0; i != NumElems; ++i) {
2651 if (V->getOperand(i).getOpcode() != ISD::UNDEF &&
2652 V->getOperand(i) != Base) {
2657 // Splat of <x, x, x, x>, return <x, x, x, x>
2664 // If it is a unary or the LHS and the RHS are the same node, turn the RHS
2666 if (isUnary || N0 == N1) {
2667 if (N0.getOpcode() == ISD::UNDEF)
2668 return DAG.getNode(ISD::UNDEF, N->getValueType(0));
2669 // Check the SHUFFLE mask, mapping any inputs from the 2nd operand into the
2671 std::vector<SDOperand> MappedOps;
2672 for (unsigned i = 0, e = ShufMask.getNumOperands(); i != e; ++i) {
2673 if (ShufMask.getOperand(i).getOpcode() == ISD::UNDEF ||
2674 cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() < NumElts) {
2675 MappedOps.push_back(ShufMask.getOperand(i));
2678 cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() - NumElts;
2679 MappedOps.push_back(DAG.getConstant(NewIdx, MVT::i32));
2682 ShufMask = DAG.getNode(ISD::BUILD_VECTOR, ShufMask.getValueType(),
2684 AddToWorkList(ShufMask.Val);
2685 return DAG.getNode(ISD::VECTOR_SHUFFLE, N->getValueType(0),
2687 DAG.getNode(ISD::UNDEF, N->getValueType(0)),
2694 SDOperand DAGCombiner::visitVVECTOR_SHUFFLE(SDNode *N) {
2695 SDOperand ShufMask = N->getOperand(2);
2696 unsigned NumElts = ShufMask.getNumOperands()-2;
2698 // If the shuffle mask is an identity operation on the LHS, return the LHS.
2699 bool isIdentity = true;
2700 for (unsigned i = 0; i != NumElts; ++i) {
2701 if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF &&
2702 cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() != i) {
2707 if (isIdentity) return N->getOperand(0);
2709 // If the shuffle mask is an identity operation on the RHS, return the RHS.
2711 for (unsigned i = 0; i != NumElts; ++i) {
2712 if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF &&
2713 cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() != i+NumElts) {
2718 if (isIdentity) return N->getOperand(1);
2720 // Check if the shuffle is a unary shuffle, i.e. one of the vectors is not
2722 bool isUnary = true;
2723 bool isSplat = true;
2725 unsigned BaseIdx = 0;
2726 for (unsigned i = 0; i != NumElts; ++i)
2727 if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF) {
2728 unsigned Idx = cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue();
2729 int V = (Idx < NumElts) ? 0 : 1;
2743 SDOperand N0 = N->getOperand(0);
2744 SDOperand N1 = N->getOperand(1);
2745 // Normalize unary shuffle so the RHS is undef.
2746 if (isUnary && VecNum == 1)
2749 // If it is a splat, check if the argument vector is a build_vector with
2750 // all scalar elements the same.
2753 if (V->getOpcode() == ISD::VBIT_CONVERT)
2754 V = V->getOperand(0).Val;
2755 if (V->getOpcode() == ISD::VBUILD_VECTOR) {
2756 unsigned NumElems = V->getNumOperands()-2;
2757 if (NumElems > BaseIdx) {
2759 bool AllSame = true;
2760 for (unsigned i = 0; i != NumElems; ++i) {
2761 if (V->getOperand(i).getOpcode() != ISD::UNDEF) {
2762 Base = V->getOperand(i);
2766 // Splat of <u, u, u, u>, return <u, u, u, u>
2769 for (unsigned i = 0; i != NumElems; ++i) {
2770 if (V->getOperand(i).getOpcode() != ISD::UNDEF &&
2771 V->getOperand(i) != Base) {
2776 // Splat of <x, x, x, x>, return <x, x, x, x>
2783 // If it is a unary or the LHS and the RHS are the same node, turn the RHS
2785 if (isUnary || N0 == N1) {
2786 // Check the SHUFFLE mask, mapping any inputs from the 2nd operand into the
2788 std::vector<SDOperand> MappedOps;
2789 for (unsigned i = 0; i != NumElts; ++i) {
2790 if (ShufMask.getOperand(i).getOpcode() == ISD::UNDEF ||
2791 cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() < NumElts) {
2792 MappedOps.push_back(ShufMask.getOperand(i));
2795 cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() - NumElts;
2796 MappedOps.push_back(DAG.getConstant(NewIdx, MVT::i32));
2799 // Add the type/#elts values.
2800 MappedOps.push_back(ShufMask.getOperand(NumElts));
2801 MappedOps.push_back(ShufMask.getOperand(NumElts+1));
2803 ShufMask = DAG.getNode(ISD::VBUILD_VECTOR, ShufMask.getValueType(),
2805 AddToWorkList(ShufMask.Val);
2807 // Build the undef vector.
2808 SDOperand UDVal = DAG.getNode(ISD::UNDEF, MappedOps[0].getValueType());
2809 for (unsigned i = 0; i != NumElts; ++i)
2810 MappedOps[i] = UDVal;
2811 MappedOps[NumElts ] = *(N0.Val->op_end()-2);
2812 MappedOps[NumElts+1] = *(N0.Val->op_end()-1);
2813 UDVal = DAG.getNode(ISD::VBUILD_VECTOR, MVT::Vector, MappedOps);
2815 return DAG.getNode(ISD::VVECTOR_SHUFFLE, MVT::Vector,
2816 N0, UDVal, ShufMask,
2817 MappedOps[NumElts], MappedOps[NumElts+1]);
2823 /// XformToShuffleWithZero - Returns a vector_shuffle if it able to transform
2824 /// a VAND to a vector_shuffle with the destination vector and a zero vector.
2825 /// e.g. VAND V, <0xffffffff, 0, 0xffffffff, 0>. ==>
2826 /// vector_shuffle V, Zero, <0, 4, 2, 4>
2827 SDOperand DAGCombiner::XformToShuffleWithZero(SDNode *N) {
2828 SDOperand LHS = N->getOperand(0);
2829 SDOperand RHS = N->getOperand(1);
2830 if (N->getOpcode() == ISD::VAND) {
2831 SDOperand DstVecSize = *(LHS.Val->op_end()-2);
2832 SDOperand DstVecEVT = *(LHS.Val->op_end()-1);
2833 if (RHS.getOpcode() == ISD::VBIT_CONVERT)
2834 RHS = RHS.getOperand(0);
2835 if (RHS.getOpcode() == ISD::VBUILD_VECTOR) {
2836 std::vector<SDOperand> IdxOps;
2837 unsigned NumOps = RHS.getNumOperands();
2838 unsigned NumElts = NumOps-2;
2839 MVT::ValueType EVT = cast<VTSDNode>(RHS.getOperand(NumOps-1))->getVT();
2840 for (unsigned i = 0; i != NumElts; ++i) {
2841 SDOperand Elt = RHS.getOperand(i);
2842 if (!isa<ConstantSDNode>(Elt))
2844 else if (cast<ConstantSDNode>(Elt)->isAllOnesValue())
2845 IdxOps.push_back(DAG.getConstant(i, EVT));
2846 else if (cast<ConstantSDNode>(Elt)->isNullValue())
2847 IdxOps.push_back(DAG.getConstant(NumElts, EVT));
2852 // Let's see if the target supports this vector_shuffle.
2853 if (!TLI.isVectorClearMaskLegal(IdxOps, EVT, DAG))
2856 // Return the new VVECTOR_SHUFFLE node.
2857 SDOperand NumEltsNode = DAG.getConstant(NumElts, MVT::i32);
2858 SDOperand EVTNode = DAG.getValueType(EVT);
2859 std::vector<SDOperand> Ops;
2860 LHS = DAG.getNode(ISD::VBIT_CONVERT, MVT::Vector, LHS, NumEltsNode, EVTNode);
2862 AddToWorkList(LHS.Val);
2863 std::vector<SDOperand> ZeroOps(NumElts, DAG.getConstant(0, EVT));
2864 ZeroOps.push_back(NumEltsNode);
2865 ZeroOps.push_back(EVTNode);
2866 Ops.push_back(DAG.getNode(ISD::VBUILD_VECTOR, MVT::Vector, ZeroOps));
2867 IdxOps.push_back(NumEltsNode);
2868 IdxOps.push_back(EVTNode);
2869 Ops.push_back(DAG.getNode(ISD::VBUILD_VECTOR, MVT::Vector, IdxOps));
2870 Ops.push_back(NumEltsNode);
2871 Ops.push_back(EVTNode);
2872 SDOperand Result = DAG.getNode(ISD::VVECTOR_SHUFFLE, MVT::Vector, Ops);
2873 if (NumEltsNode != DstVecSize || EVTNode != DstVecEVT) {
2874 Result = DAG.getNode(ISD::VBIT_CONVERT, MVT::Vector, Result,
2875 DstVecSize, DstVecEVT);
2883 /// visitVBinOp - Visit a binary vector operation, like VADD. IntOp indicates
2884 /// the scalar operation of the vop if it is operating on an integer vector
2885 /// (e.g. ADD) and FPOp indicates the FP version (e.g. FADD).
2886 SDOperand DAGCombiner::visitVBinOp(SDNode *N, ISD::NodeType IntOp,
2887 ISD::NodeType FPOp) {
2888 MVT::ValueType EltType = cast<VTSDNode>(*(N->op_end()-1))->getVT();
2889 ISD::NodeType ScalarOp = MVT::isInteger(EltType) ? IntOp : FPOp;
2890 SDOperand LHS = N->getOperand(0);
2891 SDOperand RHS = N->getOperand(1);
2892 SDOperand Shuffle = XformToShuffleWithZero(N);
2893 if (Shuffle.Val) return Shuffle;
2895 // If the LHS and RHS are VBUILD_VECTOR nodes, see if we can constant fold
2897 if (LHS.getOpcode() == ISD::VBUILD_VECTOR &&
2898 RHS.getOpcode() == ISD::VBUILD_VECTOR) {
2899 std::vector<SDOperand> Ops;
2900 for (unsigned i = 0, e = LHS.getNumOperands()-2; i != e; ++i) {
2901 SDOperand LHSOp = LHS.getOperand(i);
2902 SDOperand RHSOp = RHS.getOperand(i);
2903 // If these two elements can't be folded, bail out.
2904 if ((LHSOp.getOpcode() != ISD::UNDEF &&
2905 LHSOp.getOpcode() != ISD::Constant &&
2906 LHSOp.getOpcode() != ISD::ConstantFP) ||
2907 (RHSOp.getOpcode() != ISD::UNDEF &&
2908 RHSOp.getOpcode() != ISD::Constant &&
2909 RHSOp.getOpcode() != ISD::ConstantFP))
2911 // Can't fold divide by zero.
2912 if (N->getOpcode() == ISD::VSDIV || N->getOpcode() == ISD::VUDIV) {
2913 if ((RHSOp.getOpcode() == ISD::Constant &&
2914 cast<ConstantSDNode>(RHSOp.Val)->isNullValue()) ||
2915 (RHSOp.getOpcode() == ISD::ConstantFP &&
2916 !cast<ConstantFPSDNode>(RHSOp.Val)->getValue()))
2919 Ops.push_back(DAG.getNode(ScalarOp, EltType, LHSOp, RHSOp));
2920 AddToWorkList(Ops.back().Val);
2921 assert((Ops.back().getOpcode() == ISD::UNDEF ||
2922 Ops.back().getOpcode() == ISD::Constant ||
2923 Ops.back().getOpcode() == ISD::ConstantFP) &&
2924 "Scalar binop didn't fold!");
2927 if (Ops.size() == LHS.getNumOperands()-2) {
2928 Ops.push_back(*(LHS.Val->op_end()-2));
2929 Ops.push_back(*(LHS.Val->op_end()-1));
2930 return DAG.getNode(ISD::VBUILD_VECTOR, MVT::Vector, Ops);
2937 SDOperand DAGCombiner::SimplifySelect(SDOperand N0, SDOperand N1, SDOperand N2){
2938 assert(N0.getOpcode() ==ISD::SETCC && "First argument must be a SetCC node!");
2940 SDOperand SCC = SimplifySelectCC(N0.getOperand(0), N0.getOperand(1), N1, N2,
2941 cast<CondCodeSDNode>(N0.getOperand(2))->get());
2942 // If we got a simplified select_cc node back from SimplifySelectCC, then
2943 // break it down into a new SETCC node, and a new SELECT node, and then return
2944 // the SELECT node, since we were called with a SELECT node.
2946 // Check to see if we got a select_cc back (to turn into setcc/select).
2947 // Otherwise, just return whatever node we got back, like fabs.
2948 if (SCC.getOpcode() == ISD::SELECT_CC) {
2949 SDOperand SETCC = DAG.getNode(ISD::SETCC, N0.getValueType(),
2950 SCC.getOperand(0), SCC.getOperand(1),
2952 AddToWorkList(SETCC.Val);
2953 return DAG.getNode(ISD::SELECT, SCC.getValueType(), SCC.getOperand(2),
2954 SCC.getOperand(3), SETCC);
2961 /// SimplifySelectOps - Given a SELECT or a SELECT_CC node, where LHS and RHS
2962 /// are the two values being selected between, see if we can simplify the
2963 /// select. Callers of this should assume that TheSelect is deleted if this
2964 /// returns true. As such, they should return the appropriate thing (e.g. the
2965 /// node) back to the top-level of the DAG combiner loop to avoid it being
2968 bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDOperand LHS,
2971 // If this is a select from two identical things, try to pull the operation
2972 // through the select.
2973 if (LHS.getOpcode() == RHS.getOpcode() && LHS.hasOneUse() && RHS.hasOneUse()){
2975 std::cerr << "SELECT: ["; LHS.Val->dump();
2976 std::cerr << "] ["; RHS.Val->dump();
2980 // If this is a load and the token chain is identical, replace the select
2981 // of two loads with a load through a select of the address to load from.
2982 // This triggers in things like "select bool X, 10.0, 123.0" after the FP
2983 // constants have been dropped into the constant pool.
2984 if ((LHS.getOpcode() == ISD::LOAD ||
2985 LHS.getOpcode() == ISD::EXTLOAD ||
2986 LHS.getOpcode() == ISD::ZEXTLOAD ||
2987 LHS.getOpcode() == ISD::SEXTLOAD) &&
2988 // Token chains must be identical.
2989 LHS.getOperand(0) == RHS.getOperand(0) &&
2990 // If this is an EXTLOAD, the VT's must match.
2991 (LHS.getOpcode() == ISD::LOAD ||
2992 LHS.getOperand(3) == RHS.getOperand(3))) {
2993 // FIXME: this conflates two src values, discarding one. This is not
2994 // the right thing to do, but nothing uses srcvalues now. When they do,
2995 // turn SrcValue into a list of locations.
2997 if (TheSelect->getOpcode() == ISD::SELECT)
2998 Addr = DAG.getNode(ISD::SELECT, LHS.getOperand(1).getValueType(),
2999 TheSelect->getOperand(0), LHS.getOperand(1),
3002 Addr = DAG.getNode(ISD::SELECT_CC, LHS.getOperand(1).getValueType(),
3003 TheSelect->getOperand(0),
3004 TheSelect->getOperand(1),
3005 LHS.getOperand(1), RHS.getOperand(1),
3006 TheSelect->getOperand(4));
3009 if (LHS.getOpcode() == ISD::LOAD)
3010 Load = DAG.getLoad(TheSelect->getValueType(0), LHS.getOperand(0),
3011 Addr, LHS.getOperand(2));
3013 Load = DAG.getExtLoad(LHS.getOpcode(), TheSelect->getValueType(0),
3014 LHS.getOperand(0), Addr, LHS.getOperand(2),
3015 cast<VTSDNode>(LHS.getOperand(3))->getVT());
3016 // Users of the select now use the result of the load.
3017 CombineTo(TheSelect, Load);
3019 // Users of the old loads now use the new load's chain. We know the
3020 // old-load value is dead now.
3021 CombineTo(LHS.Val, Load.getValue(0), Load.getValue(1));
3022 CombineTo(RHS.Val, Load.getValue(0), Load.getValue(1));
3030 SDOperand DAGCombiner::SimplifySelectCC(SDOperand N0, SDOperand N1,
3031 SDOperand N2, SDOperand N3,
3034 MVT::ValueType VT = N2.getValueType();
3035 //ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.Val);
3036 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
3037 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val);
3038 ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N3.Val);
3040 // Determine if the condition we're dealing with is constant
3041 SDOperand SCC = SimplifySetCC(TLI.getSetCCResultTy(), N0, N1, CC, false);
3042 ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.Val);
3044 // fold select_cc true, x, y -> x
3045 if (SCCC && SCCC->getValue())
3047 // fold select_cc false, x, y -> y
3048 if (SCCC && SCCC->getValue() == 0)
3051 // Check to see if we can simplify the select into an fabs node
3052 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1)) {
3053 // Allow either -0.0 or 0.0
3054 if (CFP->getValue() == 0.0) {
3055 // select (setg[te] X, +/-0.0), X, fneg(X) -> fabs
3056 if ((CC == ISD::SETGE || CC == ISD::SETGT) &&
3057 N0 == N2 && N3.getOpcode() == ISD::FNEG &&
3058 N2 == N3.getOperand(0))
3059 return DAG.getNode(ISD::FABS, VT, N0);
3061 // select (setl[te] X, +/-0.0), fneg(X), X -> fabs
3062 if ((CC == ISD::SETLT || CC == ISD::SETLE) &&
3063 N0 == N3 && N2.getOpcode() == ISD::FNEG &&
3064 N2.getOperand(0) == N3)
3065 return DAG.getNode(ISD::FABS, VT, N3);
3069 // Check to see if we can perform the "gzip trick", transforming
3070 // select_cc setlt X, 0, A, 0 -> and (sra X, size(X)-1), A
3071 if (N1C && N1C->isNullValue() && N3C && N3C->isNullValue() &&
3072 MVT::isInteger(N0.getValueType()) &&
3073 MVT::isInteger(N2.getValueType()) && CC == ISD::SETLT) {
3074 MVT::ValueType XType = N0.getValueType();
3075 MVT::ValueType AType = N2.getValueType();
3076 if (XType >= AType) {
3077 // and (sra X, size(X)-1, A) -> "and (srl X, C2), A" iff A is a
3078 // single-bit constant.
3079 if (N2C && ((N2C->getValue() & (N2C->getValue()-1)) == 0)) {
3080 unsigned ShCtV = Log2_64(N2C->getValue());
3081 ShCtV = MVT::getSizeInBits(XType)-ShCtV-1;
3082 SDOperand ShCt = DAG.getConstant(ShCtV, TLI.getShiftAmountTy());
3083 SDOperand Shift = DAG.getNode(ISD::SRL, XType, N0, ShCt);
3084 AddToWorkList(Shift.Val);
3085 if (XType > AType) {
3086 Shift = DAG.getNode(ISD::TRUNCATE, AType, Shift);
3087 AddToWorkList(Shift.Val);
3089 return DAG.getNode(ISD::AND, AType, Shift, N2);
3091 SDOperand Shift = DAG.getNode(ISD::SRA, XType, N0,
3092 DAG.getConstant(MVT::getSizeInBits(XType)-1,
3093 TLI.getShiftAmountTy()));
3094 AddToWorkList(Shift.Val);
3095 if (XType > AType) {
3096 Shift = DAG.getNode(ISD::TRUNCATE, AType, Shift);
3097 AddToWorkList(Shift.Val);
3099 return DAG.getNode(ISD::AND, AType, Shift, N2);
3103 // fold select C, 16, 0 -> shl C, 4
3104 if (N2C && N3C && N3C->isNullValue() && isPowerOf2_64(N2C->getValue()) &&
3105 TLI.getSetCCResultContents() == TargetLowering::ZeroOrOneSetCCResult) {
3106 // Get a SetCC of the condition
3107 // FIXME: Should probably make sure that setcc is legal if we ever have a
3108 // target where it isn't.
3109 SDOperand Temp, SCC;
3110 // cast from setcc result type to select result type
3111 if (AfterLegalize) {
3112 SCC = DAG.getSetCC(TLI.getSetCCResultTy(), N0, N1, CC);
3113 Temp = DAG.getZeroExtendInReg(SCC, N2.getValueType());
3115 SCC = DAG.getSetCC(MVT::i1, N0, N1, CC);
3116 Temp = DAG.getNode(ISD::ZERO_EXTEND, N2.getValueType(), SCC);
3118 AddToWorkList(SCC.Val);
3119 AddToWorkList(Temp.Val);
3120 // shl setcc result by log2 n2c
3121 return DAG.getNode(ISD::SHL, N2.getValueType(), Temp,
3122 DAG.getConstant(Log2_64(N2C->getValue()),
3123 TLI.getShiftAmountTy()));
3126 // Check to see if this is the equivalent of setcc
3127 // FIXME: Turn all of these into setcc if setcc if setcc is legal
3128 // otherwise, go ahead with the folds.
3129 if (0 && N3C && N3C->isNullValue() && N2C && (N2C->getValue() == 1ULL)) {
3130 MVT::ValueType XType = N0.getValueType();
3131 if (TLI.isOperationLegal(ISD::SETCC, TLI.getSetCCResultTy())) {
3132 SDOperand Res = DAG.getSetCC(TLI.getSetCCResultTy(), N0, N1, CC);
3133 if (Res.getValueType() != VT)
3134 Res = DAG.getNode(ISD::ZERO_EXTEND, VT, Res);
3138 // seteq X, 0 -> srl (ctlz X, log2(size(X)))
3139 if (N1C && N1C->isNullValue() && CC == ISD::SETEQ &&
3140 TLI.isOperationLegal(ISD::CTLZ, XType)) {
3141 SDOperand Ctlz = DAG.getNode(ISD::CTLZ, XType, N0);
3142 return DAG.getNode(ISD::SRL, XType, Ctlz,
3143 DAG.getConstant(Log2_32(MVT::getSizeInBits(XType)),
3144 TLI.getShiftAmountTy()));
3146 // setgt X, 0 -> srl (and (-X, ~X), size(X)-1)
3147 if (N1C && N1C->isNullValue() && CC == ISD::SETGT) {
3148 SDOperand NegN0 = DAG.getNode(ISD::SUB, XType, DAG.getConstant(0, XType),
3150 SDOperand NotN0 = DAG.getNode(ISD::XOR, XType, N0,
3151 DAG.getConstant(~0ULL, XType));
3152 return DAG.getNode(ISD::SRL, XType,
3153 DAG.getNode(ISD::AND, XType, NegN0, NotN0),
3154 DAG.getConstant(MVT::getSizeInBits(XType)-1,
3155 TLI.getShiftAmountTy()));
3157 // setgt X, -1 -> xor (srl (X, size(X)-1), 1)
3158 if (N1C && N1C->isAllOnesValue() && CC == ISD::SETGT) {
3159 SDOperand Sign = DAG.getNode(ISD::SRL, XType, N0,
3160 DAG.getConstant(MVT::getSizeInBits(XType)-1,
3161 TLI.getShiftAmountTy()));
3162 return DAG.getNode(ISD::XOR, XType, Sign, DAG.getConstant(1, XType));
3166 // Check to see if this is an integer abs. select_cc setl[te] X, 0, -X, X ->
3167 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
3168 if (N1C && N1C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE) &&
3169 N0 == N3 && N2.getOpcode() == ISD::SUB && N0 == N2.getOperand(1)) {
3170 if (ConstantSDNode *SubC = dyn_cast<ConstantSDNode>(N2.getOperand(0))) {
3171 MVT::ValueType XType = N0.getValueType();
3172 if (SubC->isNullValue() && MVT::isInteger(XType)) {
3173 SDOperand Shift = DAG.getNode(ISD::SRA, XType, N0,
3174 DAG.getConstant(MVT::getSizeInBits(XType)-1,
3175 TLI.getShiftAmountTy()));
3176 SDOperand Add = DAG.getNode(ISD::ADD, XType, N0, Shift);
3177 AddToWorkList(Shift.Val);
3178 AddToWorkList(Add.Val);
3179 return DAG.getNode(ISD::XOR, XType, Add, Shift);
3187 SDOperand DAGCombiner::SimplifySetCC(MVT::ValueType VT, SDOperand N0,
3188 SDOperand N1, ISD::CondCode Cond,
3189 bool foldBooleans) {
3190 // These setcc operations always fold.
3194 case ISD::SETFALSE2: return DAG.getConstant(0, VT);
3196 case ISD::SETTRUE2: return DAG.getConstant(1, VT);
3199 if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val)) {
3200 uint64_t C1 = N1C->getValue();
3201 if (ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.Val)) {
3202 uint64_t C0 = N0C->getValue();
3204 // Sign extend the operands if required
3205 if (ISD::isSignedIntSetCC(Cond)) {
3206 C0 = N0C->getSignExtended();
3207 C1 = N1C->getSignExtended();
3211 default: assert(0 && "Unknown integer setcc!");
3212 case ISD::SETEQ: return DAG.getConstant(C0 == C1, VT);
3213 case ISD::SETNE: return DAG.getConstant(C0 != C1, VT);
3214 case ISD::SETULT: return DAG.getConstant(C0 < C1, VT);
3215 case ISD::SETUGT: return DAG.getConstant(C0 > C1, VT);
3216 case ISD::SETULE: return DAG.getConstant(C0 <= C1, VT);
3217 case ISD::SETUGE: return DAG.getConstant(C0 >= C1, VT);
3218 case ISD::SETLT: return DAG.getConstant((int64_t)C0 < (int64_t)C1, VT);
3219 case ISD::SETGT: return DAG.getConstant((int64_t)C0 > (int64_t)C1, VT);
3220 case ISD::SETLE: return DAG.getConstant((int64_t)C0 <= (int64_t)C1, VT);
3221 case ISD::SETGE: return DAG.getConstant((int64_t)C0 >= (int64_t)C1, VT);
3224 // If the LHS is a ZERO_EXTEND, perform the comparison on the input.
3225 if (N0.getOpcode() == ISD::ZERO_EXTEND) {
3226 unsigned InSize = MVT::getSizeInBits(N0.getOperand(0).getValueType());
3228 // If the comparison constant has bits in the upper part, the
3229 // zero-extended value could never match.
3230 if (C1 & (~0ULL << InSize)) {
3231 unsigned VSize = MVT::getSizeInBits(N0.getValueType());
3235 case ISD::SETEQ: return DAG.getConstant(0, VT);
3238 case ISD::SETNE: return DAG.getConstant(1, VT);
3241 // True if the sign bit of C1 is set.
3242 return DAG.getConstant((C1 & (1ULL << VSize)) != 0, VT);
3245 // True if the sign bit of C1 isn't set.
3246 return DAG.getConstant((C1 & (1ULL << VSize)) == 0, VT);
3252 // Otherwise, we can perform the comparison with the low bits.
3260 return DAG.getSetCC(VT, N0.getOperand(0),
3261 DAG.getConstant(C1, N0.getOperand(0).getValueType()),
3264 break; // todo, be more careful with signed comparisons
3266 } else if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
3267 (Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
3268 MVT::ValueType ExtSrcTy = cast<VTSDNode>(N0.getOperand(1))->getVT();
3269 unsigned ExtSrcTyBits = MVT::getSizeInBits(ExtSrcTy);
3270 MVT::ValueType ExtDstTy = N0.getValueType();
3271 unsigned ExtDstTyBits = MVT::getSizeInBits(ExtDstTy);
3273 // If the extended part has any inconsistent bits, it cannot ever
3274 // compare equal. In other words, they have to be all ones or all
3277 (~0ULL >> (64-ExtSrcTyBits)) & (~0ULL << (ExtDstTyBits-1));
3278 if ((C1 & ExtBits) != 0 && (C1 & ExtBits) != ExtBits)
3279 return DAG.getConstant(Cond == ISD::SETNE, VT);
3282 MVT::ValueType Op0Ty = N0.getOperand(0).getValueType();
3283 if (Op0Ty == ExtSrcTy) {
3284 ZextOp = N0.getOperand(0);
3286 int64_t Imm = ~0ULL >> (64-ExtSrcTyBits);
3287 ZextOp = DAG.getNode(ISD::AND, Op0Ty, N0.getOperand(0),
3288 DAG.getConstant(Imm, Op0Ty));
3290 AddToWorkList(ZextOp.Val);
3291 // Otherwise, make this a use of a zext.
3292 return DAG.getSetCC(VT, ZextOp,
3293 DAG.getConstant(C1 & (~0ULL>>(64-ExtSrcTyBits)),
3296 } else if ((N1C->getValue() == 0 || N1C->getValue() == 1) &&
3297 (Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
3298 (N0.getOpcode() == ISD::XOR ||
3299 (N0.getOpcode() == ISD::AND &&
3300 N0.getOperand(0).getOpcode() == ISD::XOR &&
3301 N0.getOperand(1) == N0.getOperand(0).getOperand(1))) &&
3302 isa<ConstantSDNode>(N0.getOperand(1)) &&
3303 cast<ConstantSDNode>(N0.getOperand(1))->getValue() == 1) {
3304 // If this is (X^1) == 0/1, swap the RHS and eliminate the xor. We can
3305 // only do this if the top bits are known zero.
3306 if (TLI.MaskedValueIsZero(N1,
3307 MVT::getIntVTBitMask(N0.getValueType())-1)) {
3308 // Okay, get the un-inverted input value.
3310 if (N0.getOpcode() == ISD::XOR)
3311 Val = N0.getOperand(0);
3313 assert(N0.getOpcode() == ISD::AND &&
3314 N0.getOperand(0).getOpcode() == ISD::XOR);
3315 // ((X^1)&1)^1 -> X & 1
3316 Val = DAG.getNode(ISD::AND, N0.getValueType(),
3317 N0.getOperand(0).getOperand(0), N0.getOperand(1));
3319 return DAG.getSetCC(VT, Val, N1,
3320 Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
3324 uint64_t MinVal, MaxVal;
3325 unsigned OperandBitSize = MVT::getSizeInBits(N1C->getValueType(0));
3326 if (ISD::isSignedIntSetCC(Cond)) {
3327 MinVal = 1ULL << (OperandBitSize-1);
3328 if (OperandBitSize != 1) // Avoid X >> 64, which is undefined.
3329 MaxVal = ~0ULL >> (65-OperandBitSize);
3334 MaxVal = ~0ULL >> (64-OperandBitSize);
3337 // Canonicalize GE/LE comparisons to use GT/LT comparisons.
3338 if (Cond == ISD::SETGE || Cond == ISD::SETUGE) {
3339 if (C1 == MinVal) return DAG.getConstant(1, VT); // X >= MIN --> true
3340 --C1; // X >= C0 --> X > (C0-1)
3341 return DAG.getSetCC(VT, N0, DAG.getConstant(C1, N1.getValueType()),
3342 (Cond == ISD::SETGE) ? ISD::SETGT : ISD::SETUGT);
3345 if (Cond == ISD::SETLE || Cond == ISD::SETULE) {
3346 if (C1 == MaxVal) return DAG.getConstant(1, VT); // X <= MAX --> true
3347 ++C1; // X <= C0 --> X < (C0+1)
3348 return DAG.getSetCC(VT, N0, DAG.getConstant(C1, N1.getValueType()),
3349 (Cond == ISD::SETLE) ? ISD::SETLT : ISD::SETULT);
3352 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal)
3353 return DAG.getConstant(0, VT); // X < MIN --> false
3355 // Canonicalize setgt X, Min --> setne X, Min
3356 if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MinVal)
3357 return DAG.getSetCC(VT, N0, N1, ISD::SETNE);
3358 // Canonicalize setlt X, Max --> setne X, Max
3359 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MaxVal)
3360 return DAG.getSetCC(VT, N0, N1, ISD::SETNE);
3362 // If we have setult X, 1, turn it into seteq X, 0
3363 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal+1)
3364 return DAG.getSetCC(VT, N0, DAG.getConstant(MinVal, N0.getValueType()),
3366 // If we have setugt X, Max-1, turn it into seteq X, Max
3367 else if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal-1)
3368 return DAG.getSetCC(VT, N0, DAG.getConstant(MaxVal, N0.getValueType()),
3371 // If we have "setcc X, C0", check to see if we can shrink the immediate
3374 // SETUGT X, SINTMAX -> SETLT X, 0
3375 if (Cond == ISD::SETUGT && OperandBitSize != 1 &&
3376 C1 == (~0ULL >> (65-OperandBitSize)))
3377 return DAG.getSetCC(VT, N0, DAG.getConstant(0, N1.getValueType()),
3380 // FIXME: Implement the rest of these.
3382 // Fold bit comparisons when we can.
3383 if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
3384 VT == N0.getValueType() && N0.getOpcode() == ISD::AND)
3385 if (ConstantSDNode *AndRHS =
3386 dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
3387 if (Cond == ISD::SETNE && C1 == 0) {// (X & 8) != 0 --> (X & 8) >> 3
3388 // Perform the xform if the AND RHS is a single bit.
3389 if ((AndRHS->getValue() & (AndRHS->getValue()-1)) == 0) {
3390 return DAG.getNode(ISD::SRL, VT, N0,
3391 DAG.getConstant(Log2_64(AndRHS->getValue()),
3392 TLI.getShiftAmountTy()));
3394 } else if (Cond == ISD::SETEQ && C1 == AndRHS->getValue()) {
3395 // (X & 8) == 8 --> (X & 8) >> 3
3396 // Perform the xform if C1 is a single bit.
3397 if ((C1 & (C1-1)) == 0) {
3398 return DAG.getNode(ISD::SRL, VT, N0,
3399 DAG.getConstant(Log2_64(C1),TLI.getShiftAmountTy()));
3404 } else if (isa<ConstantSDNode>(N0.Val)) {
3405 // Ensure that the constant occurs on the RHS.
3406 return DAG.getSetCC(VT, N1, N0, ISD::getSetCCSwappedOperands(Cond));
3409 if (ConstantFPSDNode *N0C = dyn_cast<ConstantFPSDNode>(N0.Val))
3410 if (ConstantFPSDNode *N1C = dyn_cast<ConstantFPSDNode>(N1.Val)) {
3411 double C0 = N0C->getValue(), C1 = N1C->getValue();
3414 default: break; // FIXME: Implement the rest of these!
3415 case ISD::SETEQ: return DAG.getConstant(C0 == C1, VT);
3416 case ISD::SETNE: return DAG.getConstant(C0 != C1, VT);
3417 case ISD::SETLT: return DAG.getConstant(C0 < C1, VT);
3418 case ISD::SETGT: return DAG.getConstant(C0 > C1, VT);
3419 case ISD::SETLE: return DAG.getConstant(C0 <= C1, VT);
3420 case ISD::SETGE: return DAG.getConstant(C0 >= C1, VT);
3423 // Ensure that the constant occurs on the RHS.
3424 return DAG.getSetCC(VT, N1, N0, ISD::getSetCCSwappedOperands(Cond));
3428 // We can always fold X == Y for integer setcc's.
3429 if (MVT::isInteger(N0.getValueType()))
3430 return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT);
3431 unsigned UOF = ISD::getUnorderedFlavor(Cond);
3432 if (UOF == 2) // FP operators that are undefined on NaNs.
3433 return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT);
3434 if (UOF == unsigned(ISD::isTrueWhenEqual(Cond)))
3435 return DAG.getConstant(UOF, VT);
3436 // Otherwise, we can't fold it. However, we can simplify it to SETUO/SETO
3437 // if it is not already.
3438 ISD::CondCode NewCond = UOF == 0 ? ISD::SETO : ISD::SETUO;
3439 if (NewCond != Cond)
3440 return DAG.getSetCC(VT, N0, N1, NewCond);
3443 if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
3444 MVT::isInteger(N0.getValueType())) {
3445 if (N0.getOpcode() == ISD::ADD || N0.getOpcode() == ISD::SUB ||
3446 N0.getOpcode() == ISD::XOR) {
3447 // Simplify (X+Y) == (X+Z) --> Y == Z
3448 if (N0.getOpcode() == N1.getOpcode()) {
3449 if (N0.getOperand(0) == N1.getOperand(0))
3450 return DAG.getSetCC(VT, N0.getOperand(1), N1.getOperand(1), Cond);
3451 if (N0.getOperand(1) == N1.getOperand(1))
3452 return DAG.getSetCC(VT, N0.getOperand(0), N1.getOperand(0), Cond);
3453 if (isCommutativeBinOp(N0.getOpcode())) {
3454 // If X op Y == Y op X, try other combinations.
3455 if (N0.getOperand(0) == N1.getOperand(1))
3456 return DAG.getSetCC(VT, N0.getOperand(1), N1.getOperand(0), Cond);
3457 if (N0.getOperand(1) == N1.getOperand(0))
3458 return DAG.getSetCC(VT, N0.getOperand(0), N1.getOperand(1), Cond);
3462 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(N1)) {
3463 if (ConstantSDNode *LHSR = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
3464 // Turn (X+C1) == C2 --> X == C2-C1
3465 if (N0.getOpcode() == ISD::ADD && N0.Val->hasOneUse()) {
3466 return DAG.getSetCC(VT, N0.getOperand(0),
3467 DAG.getConstant(RHSC->getValue()-LHSR->getValue(),
3468 N0.getValueType()), Cond);
3471 // Turn (X^C1) == C2 into X == C1^C2 iff X&~C1 = 0.
3472 if (N0.getOpcode() == ISD::XOR)
3473 // If we know that all of the inverted bits are zero, don't bother
3474 // performing the inversion.
3475 if (TLI.MaskedValueIsZero(N0.getOperand(0), ~LHSR->getValue()))
3476 return DAG.getSetCC(VT, N0.getOperand(0),
3477 DAG.getConstant(LHSR->getValue()^RHSC->getValue(),
3478 N0.getValueType()), Cond);
3481 // Turn (C1-X) == C2 --> X == C1-C2
3482 if (ConstantSDNode *SUBC = dyn_cast<ConstantSDNode>(N0.getOperand(0))) {
3483 if (N0.getOpcode() == ISD::SUB && N0.Val->hasOneUse()) {
3484 return DAG.getSetCC(VT, N0.getOperand(1),
3485 DAG.getConstant(SUBC->getValue()-RHSC->getValue(),
3486 N0.getValueType()), Cond);
3491 // Simplify (X+Z) == X --> Z == 0
3492 if (N0.getOperand(0) == N1)
3493 return DAG.getSetCC(VT, N0.getOperand(1),
3494 DAG.getConstant(0, N0.getValueType()), Cond);
3495 if (N0.getOperand(1) == N1) {
3496 if (isCommutativeBinOp(N0.getOpcode()))
3497 return DAG.getSetCC(VT, N0.getOperand(0),
3498 DAG.getConstant(0, N0.getValueType()), Cond);
3500 assert(N0.getOpcode() == ISD::SUB && "Unexpected operation!");
3501 // (Z-X) == X --> Z == X<<1
3502 SDOperand SH = DAG.getNode(ISD::SHL, N1.getValueType(),
3504 DAG.getConstant(1,TLI.getShiftAmountTy()));
3505 AddToWorkList(SH.Val);
3506 return DAG.getSetCC(VT, N0.getOperand(0), SH, Cond);
3511 if (N1.getOpcode() == ISD::ADD || N1.getOpcode() == ISD::SUB ||
3512 N1.getOpcode() == ISD::XOR) {
3513 // Simplify X == (X+Z) --> Z == 0
3514 if (N1.getOperand(0) == N0) {
3515 return DAG.getSetCC(VT, N1.getOperand(1),
3516 DAG.getConstant(0, N1.getValueType()), Cond);
3517 } else if (N1.getOperand(1) == N0) {
3518 if (isCommutativeBinOp(N1.getOpcode())) {
3519 return DAG.getSetCC(VT, N1.getOperand(0),
3520 DAG.getConstant(0, N1.getValueType()), Cond);
3522 assert(N1.getOpcode() == ISD::SUB && "Unexpected operation!");
3523 // X == (Z-X) --> X<<1 == Z
3524 SDOperand SH = DAG.getNode(ISD::SHL, N1.getValueType(), N0,
3525 DAG.getConstant(1,TLI.getShiftAmountTy()));
3526 AddToWorkList(SH.Val);
3527 return DAG.getSetCC(VT, SH, N1.getOperand(0), Cond);
3533 // Fold away ALL boolean setcc's.
3535 if (N0.getValueType() == MVT::i1 && foldBooleans) {
3537 default: assert(0 && "Unknown integer setcc!");
3538 case ISD::SETEQ: // X == Y -> (X^Y)^1
3539 Temp = DAG.getNode(ISD::XOR, MVT::i1, N0, N1);
3540 N0 = DAG.getNode(ISD::XOR, MVT::i1, Temp, DAG.getConstant(1, MVT::i1));
3541 AddToWorkList(Temp.Val);
3543 case ISD::SETNE: // X != Y --> (X^Y)
3544 N0 = DAG.getNode(ISD::XOR, MVT::i1, N0, N1);
3546 case ISD::SETGT: // X >s Y --> X == 0 & Y == 1 --> X^1 & Y
3547 case ISD::SETULT: // X <u Y --> X == 0 & Y == 1 --> X^1 & Y
3548 Temp = DAG.getNode(ISD::XOR, MVT::i1, N0, DAG.getConstant(1, MVT::i1));
3549 N0 = DAG.getNode(ISD::AND, MVT::i1, N1, Temp);
3550 AddToWorkList(Temp.Val);
3552 case ISD::SETLT: // X <s Y --> X == 1 & Y == 0 --> Y^1 & X
3553 case ISD::SETUGT: // X >u Y --> X == 1 & Y == 0 --> Y^1 & X
3554 Temp = DAG.getNode(ISD::XOR, MVT::i1, N1, DAG.getConstant(1, MVT::i1));
3555 N0 = DAG.getNode(ISD::AND, MVT::i1, N0, Temp);
3556 AddToWorkList(Temp.Val);
3558 case ISD::SETULE: // X <=u Y --> X == 0 | Y == 1 --> X^1 | Y
3559 case ISD::SETGE: // X >=s Y --> X == 0 | Y == 1 --> X^1 | Y
3560 Temp = DAG.getNode(ISD::XOR, MVT::i1, N0, DAG.getConstant(1, MVT::i1));
3561 N0 = DAG.getNode(ISD::OR, MVT::i1, N1, Temp);
3562 AddToWorkList(Temp.Val);
3564 case ISD::SETUGE: // X >=u Y --> X == 1 | Y == 0 --> Y^1 | X
3565 case ISD::SETLE: // X <=s Y --> X == 1 | Y == 0 --> Y^1 | X
3566 Temp = DAG.getNode(ISD::XOR, MVT::i1, N1, DAG.getConstant(1, MVT::i1));
3567 N0 = DAG.getNode(ISD::OR, MVT::i1, N0, Temp);
3570 if (VT != MVT::i1) {
3571 AddToWorkList(N0.Val);
3572 // FIXME: If running after legalize, we probably can't do this.
3573 N0 = DAG.getNode(ISD::ZERO_EXTEND, VT, N0);
3578 // Could not fold it.
3582 /// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
3583 /// return a DAG expression to select that will generate the same value by
3584 /// multiplying by a magic number. See:
3585 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
3586 SDOperand DAGCombiner::BuildSDIV(SDNode *N) {
3587 std::vector<SDNode*> Built;
3588 SDOperand S = TLI.BuildSDIV(N, DAG, &Built);
3590 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
3596 /// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant,
3597 /// return a DAG expression to select that will generate the same value by
3598 /// multiplying by a magic number. See:
3599 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
3600 SDOperand DAGCombiner::BuildUDIV(SDNode *N) {
3601 std::vector<SDNode*> Built;
3602 SDOperand S = TLI.BuildUDIV(N, DAG, &Built);
3604 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
3610 // SelectionDAG::Combine - This is the entry point for the file.
3612 void SelectionDAG::Combine(bool RunningAfterLegalize) {
3613 /// run - This is the main entry point to this class.
3615 DAGCombiner(*this).Run(RunningAfterLegalize);