1 //===- InstCombineAndOrXor.cpp --------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the visitAnd, visitOr, and visitXor functions.
12 //===----------------------------------------------------------------------===//
14 #include "InstCombine.h"
15 #include "llvm/Intrinsics.h"
16 #include "llvm/Analysis/InstructionSimplify.h"
17 #include "llvm/Support/PatternMatch.h"
19 using namespace PatternMatch;
22 /// AddOne - Add one to a ConstantInt.
23 static Constant *AddOne(Constant *C) {
24 return ConstantExpr::getAdd(C, ConstantInt::get(C->getType(), 1));
26 /// SubOne - Subtract one from a ConstantInt.
27 static Constant *SubOne(ConstantInt *C) {
28 return ConstantInt::get(C->getContext(), C->getValue()-1);
31 /// isFreeToInvert - Return true if the specified value is free to invert (apply
32 /// ~ to). This happens in cases where the ~ can be eliminated.
33 static inline bool isFreeToInvert(Value *V) {
35 if (BinaryOperator::isNot(V))
38 // Constants can be considered to be not'ed values.
39 if (isa<ConstantInt>(V))
42 // Compares can be inverted if they have a single use.
43 if (CmpInst *CI = dyn_cast<CmpInst>(V))
44 return CI->hasOneUse();
49 static inline Value *dyn_castNotVal(Value *V) {
50 // If this is not(not(x)) don't return that this is a not: we want the two
51 // not's to be folded first.
52 if (BinaryOperator::isNot(V)) {
53 Value *Operand = BinaryOperator::getNotArgument(V);
54 if (!isFreeToInvert(Operand))
58 // Constants can be considered to be not'ed values...
59 if (ConstantInt *C = dyn_cast<ConstantInt>(V))
60 return ConstantInt::get(C->getType(), ~C->getValue());
65 /// getICmpCode - Encode a icmp predicate into a three bit mask. These bits
66 /// are carefully arranged to allow folding of expressions such as:
68 /// (A < B) | (A > B) --> (A != B)
70 /// Note that this is only valid if the first and second predicates have the
71 /// same sign. Is illegal to do: (A u< B) | (A s> B)
73 /// Three bits are used to represent the condition, as follows:
78 /// <=> Value Definition
79 /// 000 0 Always false
88 static unsigned getICmpCode(const ICmpInst *ICI) {
89 switch (ICI->getPredicate()) {
91 case ICmpInst::ICMP_UGT: return 1; // 001
92 case ICmpInst::ICMP_SGT: return 1; // 001
93 case ICmpInst::ICMP_EQ: return 2; // 010
94 case ICmpInst::ICMP_UGE: return 3; // 011
95 case ICmpInst::ICMP_SGE: return 3; // 011
96 case ICmpInst::ICMP_ULT: return 4; // 100
97 case ICmpInst::ICMP_SLT: return 4; // 100
98 case ICmpInst::ICMP_NE: return 5; // 101
99 case ICmpInst::ICMP_ULE: return 6; // 110
100 case ICmpInst::ICMP_SLE: return 6; // 110
103 llvm_unreachable("Invalid ICmp predicate!");
108 /// getFCmpCode - Similar to getICmpCode but for FCmpInst. This encodes a fcmp
109 /// predicate into a three bit mask. It also returns whether it is an ordered
110 /// predicate by reference.
111 static unsigned getFCmpCode(FCmpInst::Predicate CC, bool &isOrdered) {
114 case FCmpInst::FCMP_ORD: isOrdered = true; return 0; // 000
115 case FCmpInst::FCMP_UNO: return 0; // 000
116 case FCmpInst::FCMP_OGT: isOrdered = true; return 1; // 001
117 case FCmpInst::FCMP_UGT: return 1; // 001
118 case FCmpInst::FCMP_OEQ: isOrdered = true; return 2; // 010
119 case FCmpInst::FCMP_UEQ: return 2; // 010
120 case FCmpInst::FCMP_OGE: isOrdered = true; return 3; // 011
121 case FCmpInst::FCMP_UGE: return 3; // 011
122 case FCmpInst::FCMP_OLT: isOrdered = true; return 4; // 100
123 case FCmpInst::FCMP_ULT: return 4; // 100
124 case FCmpInst::FCMP_ONE: isOrdered = true; return 5; // 101
125 case FCmpInst::FCMP_UNE: return 5; // 101
126 case FCmpInst::FCMP_OLE: isOrdered = true; return 6; // 110
127 case FCmpInst::FCMP_ULE: return 6; // 110
130 // Not expecting FCMP_FALSE and FCMP_TRUE;
131 llvm_unreachable("Unexpected FCmp predicate!");
136 /// getICmpValue - This is the complement of getICmpCode, which turns an
137 /// opcode and two operands into either a constant true or false, or a brand
138 /// new ICmp instruction. The sign is passed in to determine which kind
139 /// of predicate to use in the new icmp instruction.
140 static Value *getICmpValue(bool Sign, unsigned Code, Value *LHS, Value *RHS,
141 InstCombiner::BuilderTy *Builder) {
142 CmpInst::Predicate Pred;
144 default: assert(0 && "Illegal ICmp code!");
146 return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
147 case 1: Pred = Sign ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT; break;
148 case 2: Pred = ICmpInst::ICMP_EQ; break;
149 case 3: Pred = Sign ? ICmpInst::ICMP_SGE : ICmpInst::ICMP_UGE; break;
150 case 4: Pred = Sign ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT; break;
151 case 5: Pred = ICmpInst::ICMP_NE; break;
152 case 6: Pred = Sign ? ICmpInst::ICMP_SLE : ICmpInst::ICMP_ULE; break;
154 return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 1);
156 return Builder->CreateICmp(Pred, LHS, RHS);
159 /// getFCmpValue - This is the complement of getFCmpCode, which turns an
160 /// opcode and two operands into either a FCmp instruction. isordered is passed
161 /// in to determine which kind of predicate to use in the new fcmp instruction.
162 static Value *getFCmpValue(bool isordered, unsigned code,
163 Value *LHS, Value *RHS,
164 InstCombiner::BuilderTy *Builder) {
165 CmpInst::Predicate Pred;
167 default: assert(0 && "Illegal FCmp code!");
168 case 0: Pred = isordered ? FCmpInst::FCMP_ORD : FCmpInst::FCMP_UNO; break;
169 case 1: Pred = isordered ? FCmpInst::FCMP_OGT : FCmpInst::FCMP_UGT; break;
170 case 2: Pred = isordered ? FCmpInst::FCMP_OEQ : FCmpInst::FCMP_UEQ; break;
171 case 3: Pred = isordered ? FCmpInst::FCMP_OGE : FCmpInst::FCMP_UGE; break;
172 case 4: Pred = isordered ? FCmpInst::FCMP_OLT : FCmpInst::FCMP_ULT; break;
173 case 5: Pred = isordered ? FCmpInst::FCMP_ONE : FCmpInst::FCMP_UNE; break;
174 case 6: Pred = isordered ? FCmpInst::FCMP_OLE : FCmpInst::FCMP_ULE; break;
175 case 7: return ConstantInt::getTrue(LHS->getContext());
177 return Builder->CreateFCmp(Pred, LHS, RHS);
180 /// PredicatesFoldable - Return true if both predicates match sign or if at
181 /// least one of them is an equality comparison (which is signless).
182 static bool PredicatesFoldable(ICmpInst::Predicate p1, ICmpInst::Predicate p2) {
183 return (CmpInst::isSigned(p1) == CmpInst::isSigned(p2)) ||
184 (CmpInst::isSigned(p1) && ICmpInst::isEquality(p2)) ||
185 (CmpInst::isSigned(p2) && ICmpInst::isEquality(p1));
188 // OptAndOp - This handles expressions of the form ((val OP C1) & C2). Where
189 // the Op parameter is 'OP', OpRHS is 'C1', and AndRHS is 'C2'. Op is
190 // guaranteed to be a binary operator.
191 Instruction *InstCombiner::OptAndOp(Instruction *Op,
194 BinaryOperator &TheAnd) {
195 Value *X = Op->getOperand(0);
196 Constant *Together = 0;
198 Together = ConstantExpr::getAnd(AndRHS, OpRHS);
200 switch (Op->getOpcode()) {
201 case Instruction::Xor:
202 if (Op->hasOneUse()) {
203 // (X ^ C1) & C2 --> (X & C2) ^ (C1&C2)
204 Value *And = Builder->CreateAnd(X, AndRHS);
206 return BinaryOperator::CreateXor(And, Together);
209 case Instruction::Or:
210 if (Op->hasOneUse() && Together != OpRHS) {
211 // (X | C1) & C2 --> (X | (C1&C2)) & C2
212 Value *Or = Builder->CreateOr(X, Together);
214 return BinaryOperator::CreateAnd(Or, AndRHS);
217 case Instruction::Add:
218 if (Op->hasOneUse()) {
219 // Adding a one to a single bit bit-field should be turned into an XOR
220 // of the bit. First thing to check is to see if this AND is with a
221 // single bit constant.
222 const APInt &AndRHSV = cast<ConstantInt>(AndRHS)->getValue();
224 // If there is only one bit set.
225 if (AndRHSV.isPowerOf2()) {
226 // Ok, at this point, we know that we are masking the result of the
227 // ADD down to exactly one bit. If the constant we are adding has
228 // no bits set below this bit, then we can eliminate the ADD.
229 const APInt& AddRHS = cast<ConstantInt>(OpRHS)->getValue();
231 // Check to see if any bits below the one bit set in AndRHSV are set.
232 if ((AddRHS & (AndRHSV-1)) == 0) {
233 // If not, the only thing that can effect the output of the AND is
234 // the bit specified by AndRHSV. If that bit is set, the effect of
235 // the XOR is to toggle the bit. If it is clear, then the ADD has
237 if ((AddRHS & AndRHSV) == 0) { // Bit is not set, noop
238 TheAnd.setOperand(0, X);
241 // Pull the XOR out of the AND.
242 Value *NewAnd = Builder->CreateAnd(X, AndRHS);
243 NewAnd->takeName(Op);
244 return BinaryOperator::CreateXor(NewAnd, AndRHS);
251 case Instruction::Shl: {
252 // We know that the AND will not produce any of the bits shifted in, so if
253 // the anded constant includes them, clear them now!
255 uint32_t BitWidth = AndRHS->getType()->getBitWidth();
256 uint32_t OpRHSVal = OpRHS->getLimitedValue(BitWidth);
257 APInt ShlMask(APInt::getHighBitsSet(BitWidth, BitWidth-OpRHSVal));
258 ConstantInt *CI = ConstantInt::get(AndRHS->getContext(),
259 AndRHS->getValue() & ShlMask);
261 if (CI->getValue() == ShlMask) {
262 // Masking out bits that the shift already masks
263 return ReplaceInstUsesWith(TheAnd, Op); // No need for the and.
264 } else if (CI != AndRHS) { // Reducing bits set in and.
265 TheAnd.setOperand(1, CI);
270 case Instruction::LShr: {
271 // We know that the AND will not produce any of the bits shifted in, so if
272 // the anded constant includes them, clear them now! This only applies to
273 // unsigned shifts, because a signed shr may bring in set bits!
275 uint32_t BitWidth = AndRHS->getType()->getBitWidth();
276 uint32_t OpRHSVal = OpRHS->getLimitedValue(BitWidth);
277 APInt ShrMask(APInt::getLowBitsSet(BitWidth, BitWidth - OpRHSVal));
278 ConstantInt *CI = ConstantInt::get(Op->getContext(),
279 AndRHS->getValue() & ShrMask);
281 if (CI->getValue() == ShrMask) {
282 // Masking out bits that the shift already masks.
283 return ReplaceInstUsesWith(TheAnd, Op);
284 } else if (CI != AndRHS) {
285 TheAnd.setOperand(1, CI); // Reduce bits set in and cst.
290 case Instruction::AShr:
292 // See if this is shifting in some sign extension, then masking it out
294 if (Op->hasOneUse()) {
295 uint32_t BitWidth = AndRHS->getType()->getBitWidth();
296 uint32_t OpRHSVal = OpRHS->getLimitedValue(BitWidth);
297 APInt ShrMask(APInt::getLowBitsSet(BitWidth, BitWidth - OpRHSVal));
298 Constant *C = ConstantInt::get(Op->getContext(),
299 AndRHS->getValue() & ShrMask);
300 if (C == AndRHS) { // Masking out bits shifted in.
301 // (Val ashr C1) & C2 -> (Val lshr C1) & C2
302 // Make the argument unsigned.
303 Value *ShVal = Op->getOperand(0);
304 ShVal = Builder->CreateLShr(ShVal, OpRHS, Op->getName());
305 return BinaryOperator::CreateAnd(ShVal, AndRHS, TheAnd.getName());
314 /// InsertRangeTest - Emit a computation of: (V >= Lo && V < Hi) if Inside is
315 /// true, otherwise (V < Lo || V >= Hi). In pratice, we emit the more efficient
316 /// (V-Lo) <u Hi-Lo. This method expects that Lo <= Hi. isSigned indicates
317 /// whether to treat the V, Lo and HI as signed or not. IB is the location to
318 /// insert new instructions.
319 Value *InstCombiner::InsertRangeTest(Value *V, Constant *Lo, Constant *Hi,
320 bool isSigned, bool Inside) {
321 assert(cast<ConstantInt>(ConstantExpr::getICmp((isSigned ?
322 ICmpInst::ICMP_SLE:ICmpInst::ICMP_ULE), Lo, Hi))->getZExtValue() &&
323 "Lo is not <= Hi in range emission code!");
326 if (Lo == Hi) // Trivially false.
327 return ConstantInt::getFalse(V->getContext());
329 // V >= Min && V < Hi --> V < Hi
330 if (cast<ConstantInt>(Lo)->isMinValue(isSigned)) {
331 ICmpInst::Predicate pred = (isSigned ?
332 ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT);
333 return Builder->CreateICmp(pred, V, Hi);
336 // Emit V-Lo <u Hi-Lo
337 Constant *NegLo = ConstantExpr::getNeg(Lo);
338 Value *Add = Builder->CreateAdd(V, NegLo, V->getName()+".off");
339 Constant *UpperBound = ConstantExpr::getAdd(NegLo, Hi);
340 return Builder->CreateICmpULT(Add, UpperBound);
343 if (Lo == Hi) // Trivially true.
344 return ConstantInt::getTrue(V->getContext());
346 // V < Min || V >= Hi -> V > Hi-1
347 Hi = SubOne(cast<ConstantInt>(Hi));
348 if (cast<ConstantInt>(Lo)->isMinValue(isSigned)) {
349 ICmpInst::Predicate pred = (isSigned ?
350 ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT);
351 return Builder->CreateICmp(pred, V, Hi);
354 // Emit V-Lo >u Hi-1-Lo
355 // Note that Hi has already had one subtracted from it, above.
356 ConstantInt *NegLo = cast<ConstantInt>(ConstantExpr::getNeg(Lo));
357 Value *Add = Builder->CreateAdd(V, NegLo, V->getName()+".off");
358 Constant *LowerBound = ConstantExpr::getAdd(NegLo, Hi);
359 return Builder->CreateICmpUGT(Add, LowerBound);
362 // isRunOfOnes - Returns true iff Val consists of one contiguous run of 1s with
363 // any number of 0s on either side. The 1s are allowed to wrap from LSB to
364 // MSB, so 0x000FFF0, 0x0000FFFF, and 0xFF0000FF are all runs. 0x0F0F0000 is
365 // not, since all 1s are not contiguous.
366 static bool isRunOfOnes(ConstantInt *Val, uint32_t &MB, uint32_t &ME) {
367 const APInt& V = Val->getValue();
368 uint32_t BitWidth = Val->getType()->getBitWidth();
369 if (!APIntOps::isShiftedMask(BitWidth, V)) return false;
371 // look for the first zero bit after the run of ones
372 MB = BitWidth - ((V - 1) ^ V).countLeadingZeros();
373 // look for the first non-zero bit
374 ME = V.getActiveBits();
378 /// FoldLogicalPlusAnd - This is part of an expression (LHS +/- RHS) & Mask,
379 /// where isSub determines whether the operator is a sub. If we can fold one of
380 /// the following xforms:
382 /// ((A & N) +/- B) & Mask -> (A +/- B) & Mask iff N&Mask == Mask
383 /// ((A | N) +/- B) & Mask -> (A +/- B) & Mask iff N&Mask == 0
384 /// ((A ^ N) +/- B) & Mask -> (A +/- B) & Mask iff N&Mask == 0
386 /// return (A +/- B).
388 Value *InstCombiner::FoldLogicalPlusAnd(Value *LHS, Value *RHS,
389 ConstantInt *Mask, bool isSub,
391 Instruction *LHSI = dyn_cast<Instruction>(LHS);
392 if (!LHSI || LHSI->getNumOperands() != 2 ||
393 !isa<ConstantInt>(LHSI->getOperand(1))) return 0;
395 ConstantInt *N = cast<ConstantInt>(LHSI->getOperand(1));
397 switch (LHSI->getOpcode()) {
399 case Instruction::And:
400 if (ConstantExpr::getAnd(N, Mask) == Mask) {
401 // If the AndRHS is a power of two minus one (0+1+), this is simple.
402 if ((Mask->getValue().countLeadingZeros() +
403 Mask->getValue().countPopulation()) ==
404 Mask->getValue().getBitWidth())
407 // Otherwise, if Mask is 0+1+0+, and if B is known to have the low 0+
408 // part, we don't need any explicit masks to take them out of A. If that
409 // is all N is, ignore it.
410 uint32_t MB = 0, ME = 0;
411 if (isRunOfOnes(Mask, MB, ME)) { // begin/end bit of run, inclusive
412 uint32_t BitWidth = cast<IntegerType>(RHS->getType())->getBitWidth();
413 APInt Mask(APInt::getLowBitsSet(BitWidth, MB-1));
414 if (MaskedValueIsZero(RHS, Mask))
419 case Instruction::Or:
420 case Instruction::Xor:
421 // If the AndRHS is a power of two minus one (0+1+), and N&Mask == 0
422 if ((Mask->getValue().countLeadingZeros() +
423 Mask->getValue().countPopulation()) == Mask->getValue().getBitWidth()
424 && ConstantExpr::getAnd(N, Mask)->isNullValue())
430 return Builder->CreateSub(LHSI->getOperand(0), RHS, "fold");
431 return Builder->CreateAdd(LHSI->getOperand(0), RHS, "fold");
434 /// enum for classifying (icmp eq (A & B), C) and (icmp ne (A & B), C)
435 /// One of A and B is considered the mask, the other the value. This is
436 /// described as the "AMask" or "BMask" part of the enum. If the enum
437 /// contains only "Mask", then both A and B can be considered masks.
438 /// If A is the mask, then it was proven, that (A & C) == C. This
439 /// is trivial if C == A, or C == 0. If both A and C are constants, this
440 /// proof is also easy.
441 /// For the following explanations we assume that A is the mask.
442 /// The part "AllOnes" declares, that the comparison is true only
443 /// if (A & B) == A, or all bits of A are set in B.
444 /// Example: (icmp eq (A & 3), 3) -> FoldMskICmp_AMask_AllOnes
445 /// The part "AllZeroes" declares, that the comparison is true only
446 /// if (A & B) == 0, or all bits of A are cleared in B.
447 /// Example: (icmp eq (A & 3), 0) -> FoldMskICmp_Mask_AllZeroes
448 /// The part "Mixed" declares, that (A & B) == C and C might or might not
449 /// contain any number of one bits and zero bits.
450 /// Example: (icmp eq (A & 3), 1) -> FoldMskICmp_AMask_Mixed
451 /// The Part "Not" means, that in above descriptions "==" should be replaced
453 /// Example: (icmp ne (A & 3), 3) -> FoldMskICmp_AMask_NotAllOnes
454 /// If the mask A contains a single bit, then the following is equivalent:
455 /// (icmp eq (A & B), A) equals (icmp ne (A & B), 0)
456 /// (icmp ne (A & B), A) equals (icmp eq (A & B), 0)
457 enum MaskedICmpType {
458 FoldMskICmp_AMask_AllOnes = 1,
459 FoldMskICmp_AMask_NotAllOnes = 2,
460 FoldMskICmp_BMask_AllOnes = 4,
461 FoldMskICmp_BMask_NotAllOnes = 8,
462 FoldMskICmp_Mask_AllZeroes = 16,
463 FoldMskICmp_Mask_NotAllZeroes = 32,
464 FoldMskICmp_AMask_Mixed = 64,
465 FoldMskICmp_AMask_NotMixed = 128,
466 FoldMskICmp_BMask_Mixed = 256,
467 FoldMskICmp_BMask_NotMixed = 512
470 /// return the set of pattern classes (from MaskedICmpType)
471 /// that (icmp SCC (A & B), C) satisfies
472 static unsigned getTypeOfMaskedICmp(Value* A, Value* B, Value* C,
473 ICmpInst::Predicate SCC)
475 ConstantInt *ACst = dyn_cast<ConstantInt>(A);
476 ConstantInt *BCst = dyn_cast<ConstantInt>(B);
477 ConstantInt *CCst = dyn_cast<ConstantInt>(C);
478 bool icmp_eq = (SCC == ICmpInst::ICMP_EQ);
479 bool icmp_abit = (ACst != 0 && !ACst->isZero() &&
480 ACst->getValue().isPowerOf2());
481 bool icmp_bbit = (BCst != 0 && !BCst->isZero() &&
482 BCst->getValue().isPowerOf2());
484 if (CCst != 0 && CCst->isZero()) {
485 // if C is zero, then both A and B qualify as mask
486 result |= (icmp_eq ? (FoldMskICmp_Mask_AllZeroes |
487 FoldMskICmp_Mask_AllZeroes |
488 FoldMskICmp_AMask_Mixed |
489 FoldMskICmp_BMask_Mixed)
490 : (FoldMskICmp_Mask_NotAllZeroes |
491 FoldMskICmp_Mask_NotAllZeroes |
492 FoldMskICmp_AMask_NotMixed |
493 FoldMskICmp_BMask_NotMixed));
495 result |= (icmp_eq ? (FoldMskICmp_AMask_NotAllOnes |
496 FoldMskICmp_AMask_NotMixed)
497 : (FoldMskICmp_AMask_AllOnes |
498 FoldMskICmp_AMask_Mixed));
500 result |= (icmp_eq ? (FoldMskICmp_BMask_NotAllOnes |
501 FoldMskICmp_BMask_NotMixed)
502 : (FoldMskICmp_BMask_AllOnes |
503 FoldMskICmp_BMask_Mixed));
507 result |= (icmp_eq ? (FoldMskICmp_AMask_AllOnes |
508 FoldMskICmp_AMask_Mixed)
509 : (FoldMskICmp_AMask_NotAllOnes |
510 FoldMskICmp_AMask_NotMixed));
512 result |= (icmp_eq ? (FoldMskICmp_Mask_NotAllZeroes |
513 FoldMskICmp_AMask_NotMixed)
514 : (FoldMskICmp_Mask_AllZeroes |
515 FoldMskICmp_AMask_Mixed));
517 else if (ACst != 0 && CCst != 0 &&
518 ConstantExpr::getAnd(ACst, CCst) == CCst) {
519 result |= (icmp_eq ? FoldMskICmp_AMask_Mixed
520 : FoldMskICmp_AMask_NotMixed);
524 result |= (icmp_eq ? (FoldMskICmp_BMask_AllOnes |
525 FoldMskICmp_BMask_Mixed)
526 : (FoldMskICmp_BMask_NotAllOnes |
527 FoldMskICmp_BMask_NotMixed));
529 result |= (icmp_eq ? (FoldMskICmp_Mask_NotAllZeroes |
530 FoldMskICmp_BMask_NotMixed)
531 : (FoldMskICmp_Mask_AllZeroes |
532 FoldMskICmp_BMask_Mixed));
534 else if (BCst != 0 && CCst != 0 &&
535 ConstantExpr::getAnd(BCst, CCst) == CCst) {
536 result |= (icmp_eq ? FoldMskICmp_BMask_Mixed
537 : FoldMskICmp_BMask_NotMixed);
542 /// foldLogOpOfMaskedICmpsHelper:
543 /// handle (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E)
544 /// return the set of pattern classes (from MaskedICmpType)
545 /// that both LHS and RHS satisfy
546 static unsigned foldLogOpOfMaskedICmpsHelper(Value*& A,
547 Value*& B, Value*& C,
548 Value*& D, Value*& E,
549 ICmpInst *LHS, ICmpInst *RHS) {
550 ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate();
551 if (LHSCC != ICmpInst::ICMP_EQ && LHSCC != ICmpInst::ICMP_NE) return 0;
552 if (RHSCC != ICmpInst::ICMP_EQ && RHSCC != ICmpInst::ICMP_NE) return 0;
553 if (LHS->getOperand(0)->getType() != RHS->getOperand(0)->getType()) return 0;
554 // vectors are not (yet?) supported
555 if (LHS->getOperand(0)->getType()->isVectorTy()) return 0;
557 // Here comes the tricky part:
558 // LHS might be of the form L11 & L12 == X, X == L21 & L22,
559 // and L11 & L12 == L21 & L22. The same goes for RHS.
560 // Now we must find those components L** and R**, that are equal, so
561 // that we can extract the parameters A, B, C, D, and E for the canonical
563 Value *L1 = LHS->getOperand(0);
564 Value *L2 = LHS->getOperand(1);
565 Value *L11,*L12,*L21,*L22;
566 if (match(L1, m_And(m_Value(L11), m_Value(L12)))) {
567 if (!match(L2, m_And(m_Value(L21), m_Value(L22))))
571 if (!match(L2, m_And(m_Value(L11), m_Value(L12))))
577 Value *R1 = RHS->getOperand(0);
578 Value *R2 = RHS->getOperand(1);
581 if (match(R1, m_And(m_Value(R11), m_Value(R12)))) {
582 if (R11 != 0 && (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22)) {
583 A = R11; D = R12; E = R2; ok = true;
586 if (R12 != 0 && (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22)) {
587 A = R12; D = R11; E = R2; ok = true;
590 if (!ok && match(R2, m_And(m_Value(R11), m_Value(R12)))) {
591 if (R11 != 0 && (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22)) {
592 A = R11; D = R12; E = R1; ok = true;
595 if (R12 != 0 && (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22)) {
596 A = R12; D = R11; E = R1; ok = true;
617 unsigned left_type = getTypeOfMaskedICmp(A, B, C, LHSCC);
618 unsigned right_type = getTypeOfMaskedICmp(A, D, E, RHSCC);
619 return left_type & right_type;
621 /// foldLogOpOfMaskedICmps:
622 /// try to fold (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E)
623 /// into a single (icmp(A & X) ==/!= Y)
624 static Value* foldLogOpOfMaskedICmps(ICmpInst *LHS, ICmpInst *RHS,
625 ICmpInst::Predicate NEWCC,
626 llvm::InstCombiner::BuilderTy* Builder) {
627 Value *A = 0, *B = 0, *C = 0, *D = 0, *E = 0;
628 unsigned mask = foldLogOpOfMaskedICmpsHelper(A, B, C, D, E, LHS, RHS);
629 if (mask == 0) return 0;
631 if (NEWCC == ICmpInst::ICMP_NE)
632 mask >>= 1; // treat "Not"-states as normal states
634 if (mask & FoldMskICmp_Mask_AllZeroes) {
635 // (icmp eq (A & B), 0) & (icmp eq (A & D), 0)
636 // -> (icmp eq (A & (B|D)), 0)
637 Value* newOr = Builder->CreateOr(B, D);
638 Value* newAnd = Builder->CreateAnd(A, newOr);
639 // we can't use C as zero, because we might actually handle
640 // (icmp ne (A & B), B) & (icmp ne (A & D), D)
641 // with B and D, having a single bit set
642 Value* zero = Constant::getNullValue(A->getType());
643 return Builder->CreateICmp(NEWCC, newAnd, zero);
645 else if (mask & FoldMskICmp_BMask_AllOnes) {
646 // (icmp eq (A & B), B) & (icmp eq (A & D), D)
647 // -> (icmp eq (A & (B|D)), (B|D))
648 Value* newOr = Builder->CreateOr(B, D);
649 Value* newAnd = Builder->CreateAnd(A, newOr);
650 return Builder->CreateICmp(NEWCC, newAnd, newOr);
652 else if (mask & FoldMskICmp_AMask_AllOnes) {
653 // (icmp eq (A & B), A) & (icmp eq (A & D), A)
654 // -> (icmp eq (A & (B&D)), A)
655 Value* newAnd1 = Builder->CreateAnd(B, D);
656 Value* newAnd = Builder->CreateAnd(A, newAnd1);
657 return Builder->CreateICmp(NEWCC, newAnd, A);
659 else if (mask & FoldMskICmp_BMask_Mixed) {
660 // (icmp eq (A & B), C) & (icmp eq (A & D), E)
661 // We already know that B & C == C && D & E == E.
662 // If we can prove that (B & D) & (C ^ E) == 0, that is, the bits of
663 // C and E, which are shared by both the mask B and the mask D, don't
664 // contradict, then we can transform to
665 // -> (icmp eq (A & (B|D)), (C|E))
666 // Currently, we only handle the case of B, C, D, and E being constant.
667 ConstantInt *BCst = dyn_cast<ConstantInt>(B);
668 if (BCst == 0) return 0;
669 ConstantInt *DCst = dyn_cast<ConstantInt>(D);
670 if (DCst == 0) return 0;
671 // we can't simply use C and E, because we might actually handle
672 // (icmp ne (A & B), B) & (icmp eq (A & D), D)
673 // with B and D, having a single bit set
675 ConstantInt *CCst = dyn_cast<ConstantInt>(C);
676 if (CCst == 0) return 0;
677 if (LHS->getPredicate() != NEWCC)
678 CCst = dyn_cast<ConstantInt>( ConstantExpr::getXor(BCst, CCst) );
679 ConstantInt *ECst = dyn_cast<ConstantInt>(E);
680 if (ECst == 0) return 0;
681 if (RHS->getPredicate() != NEWCC)
682 ECst = dyn_cast<ConstantInt>( ConstantExpr::getXor(DCst, ECst) );
683 ConstantInt* MCst = dyn_cast<ConstantInt>(
684 ConstantExpr::getAnd(ConstantExpr::getAnd(BCst, DCst),
685 ConstantExpr::getXor(CCst, ECst)) );
686 // if there is a conflict we should actually return a false for the
690 Value* newOr1 = Builder->CreateOr(B, D);
691 Value* newOr2 = ConstantExpr::getOr(CCst, ECst);
692 Value* newAnd = Builder->CreateAnd(A, newOr1);
693 return Builder->CreateICmp(NEWCC, newAnd, newOr2);
698 /// FoldAndOfICmps - Fold (icmp)&(icmp) if possible.
699 Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
700 ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate();
702 // (icmp1 A, B) & (icmp2 A, B) --> (icmp3 A, B)
703 if (PredicatesFoldable(LHSCC, RHSCC)) {
704 if (LHS->getOperand(0) == RHS->getOperand(1) &&
705 LHS->getOperand(1) == RHS->getOperand(0))
707 if (LHS->getOperand(0) == RHS->getOperand(0) &&
708 LHS->getOperand(1) == RHS->getOperand(1)) {
709 Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
710 unsigned Code = getICmpCode(LHS) & getICmpCode(RHS);
711 bool isSigned = LHS->isSigned() || RHS->isSigned();
712 return getICmpValue(isSigned, Code, Op0, Op1, Builder);
718 // (icmp eq (A & B), C) & (icmp eq (A & D), E)
719 Value* fold = foldLogOpOfMaskedICmps(LHS, RHS, ICmpInst::ICMP_EQ, Builder);
720 if (fold) return fold;
723 // This only handles icmp of constants: (icmp1 A, C1) & (icmp2 B, C2).
724 Value *Val = LHS->getOperand(0), *Val2 = RHS->getOperand(0);
725 ConstantInt *LHSCst = dyn_cast<ConstantInt>(LHS->getOperand(1));
726 ConstantInt *RHSCst = dyn_cast<ConstantInt>(RHS->getOperand(1));
727 if (LHSCst == 0 || RHSCst == 0) return 0;
729 if (LHSCst == RHSCst && LHSCC == RHSCC) {
730 // (icmp ult A, C) & (icmp ult B, C) --> (icmp ult (A|B), C)
731 // where C is a power of 2
732 if (LHSCC == ICmpInst::ICMP_ULT &&
733 LHSCst->getValue().isPowerOf2()) {
734 Value *NewOr = Builder->CreateOr(Val, Val2);
735 return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
738 // (icmp eq A, 0) & (icmp eq B, 0) --> (icmp eq (A|B), 0)
739 if (LHSCC == ICmpInst::ICMP_EQ && LHSCst->isZero()) {
740 Value *NewOr = Builder->CreateOr(Val, Val2);
741 return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
745 // From here on, we only handle:
746 // (icmp1 A, C1) & (icmp2 A, C2) --> something simpler.
747 if (Val != Val2) return 0;
749 // ICMP_[US][GL]E X, CST is folded to ICMP_[US][GL]T elsewhere.
750 if (LHSCC == ICmpInst::ICMP_UGE || LHSCC == ICmpInst::ICMP_ULE ||
751 RHSCC == ICmpInst::ICMP_UGE || RHSCC == ICmpInst::ICMP_ULE ||
752 LHSCC == ICmpInst::ICMP_SGE || LHSCC == ICmpInst::ICMP_SLE ||
753 RHSCC == ICmpInst::ICMP_SGE || RHSCC == ICmpInst::ICMP_SLE)
756 // We can't fold (ugt x, C) & (sgt x, C2).
757 if (!PredicatesFoldable(LHSCC, RHSCC))
760 // Ensure that the larger constant is on the RHS.
762 if (CmpInst::isSigned(LHSCC) ||
763 (ICmpInst::isEquality(LHSCC) &&
764 CmpInst::isSigned(RHSCC)))
765 ShouldSwap = LHSCst->getValue().sgt(RHSCst->getValue());
767 ShouldSwap = LHSCst->getValue().ugt(RHSCst->getValue());
771 std::swap(LHSCst, RHSCst);
772 std::swap(LHSCC, RHSCC);
775 // At this point, we know we have two icmp instructions
776 // comparing a value against two constants and and'ing the result
777 // together. Because of the above check, we know that we only have
778 // icmp eq, icmp ne, icmp [su]lt, and icmp [SU]gt here. We also know
779 // (from the icmp folding check above), that the two constants
780 // are not equal and that the larger constant is on the RHS
781 assert(LHSCst != RHSCst && "Compares not folded above?");
784 default: llvm_unreachable("Unknown integer condition code!");
785 case ICmpInst::ICMP_EQ:
787 default: llvm_unreachable("Unknown integer condition code!");
788 case ICmpInst::ICMP_EQ: // (X == 13 & X == 15) -> false
789 case ICmpInst::ICMP_UGT: // (X == 13 & X > 15) -> false
790 case ICmpInst::ICMP_SGT: // (X == 13 & X > 15) -> false
791 return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
792 case ICmpInst::ICMP_NE: // (X == 13 & X != 15) -> X == 13
793 case ICmpInst::ICMP_ULT: // (X == 13 & X < 15) -> X == 13
794 case ICmpInst::ICMP_SLT: // (X == 13 & X < 15) -> X == 13
797 case ICmpInst::ICMP_NE:
799 default: llvm_unreachable("Unknown integer condition code!");
800 case ICmpInst::ICMP_ULT:
801 if (LHSCst == SubOne(RHSCst)) // (X != 13 & X u< 14) -> X < 13
802 return Builder->CreateICmpULT(Val, LHSCst);
803 break; // (X != 13 & X u< 15) -> no change
804 case ICmpInst::ICMP_SLT:
805 if (LHSCst == SubOne(RHSCst)) // (X != 13 & X s< 14) -> X < 13
806 return Builder->CreateICmpSLT(Val, LHSCst);
807 break; // (X != 13 & X s< 15) -> no change
808 case ICmpInst::ICMP_EQ: // (X != 13 & X == 15) -> X == 15
809 case ICmpInst::ICMP_UGT: // (X != 13 & X u> 15) -> X u> 15
810 case ICmpInst::ICMP_SGT: // (X != 13 & X s> 15) -> X s> 15
812 case ICmpInst::ICMP_NE:
813 if (LHSCst == SubOne(RHSCst)){// (X != 13 & X != 14) -> X-13 >u 1
814 Constant *AddCST = ConstantExpr::getNeg(LHSCst);
815 Value *Add = Builder->CreateAdd(Val, AddCST, Val->getName()+".off");
816 return Builder->CreateICmpUGT(Add, ConstantInt::get(Add->getType(), 1));
818 break; // (X != 13 & X != 15) -> no change
821 case ICmpInst::ICMP_ULT:
823 default: llvm_unreachable("Unknown integer condition code!");
824 case ICmpInst::ICMP_EQ: // (X u< 13 & X == 15) -> false
825 case ICmpInst::ICMP_UGT: // (X u< 13 & X u> 15) -> false
826 return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
827 case ICmpInst::ICMP_SGT: // (X u< 13 & X s> 15) -> no change
829 case ICmpInst::ICMP_NE: // (X u< 13 & X != 15) -> X u< 13
830 case ICmpInst::ICMP_ULT: // (X u< 13 & X u< 15) -> X u< 13
832 case ICmpInst::ICMP_SLT: // (X u< 13 & X s< 15) -> no change
836 case ICmpInst::ICMP_SLT:
838 default: llvm_unreachable("Unknown integer condition code!");
839 case ICmpInst::ICMP_EQ: // (X s< 13 & X == 15) -> false
840 case ICmpInst::ICMP_SGT: // (X s< 13 & X s> 15) -> false
841 return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
842 case ICmpInst::ICMP_UGT: // (X s< 13 & X u> 15) -> no change
844 case ICmpInst::ICMP_NE: // (X s< 13 & X != 15) -> X < 13
845 case ICmpInst::ICMP_SLT: // (X s< 13 & X s< 15) -> X < 13
847 case ICmpInst::ICMP_ULT: // (X s< 13 & X u< 15) -> no change
851 case ICmpInst::ICMP_UGT:
853 default: llvm_unreachable("Unknown integer condition code!");
854 case ICmpInst::ICMP_EQ: // (X u> 13 & X == 15) -> X == 15
855 case ICmpInst::ICMP_UGT: // (X u> 13 & X u> 15) -> X u> 15
857 case ICmpInst::ICMP_SGT: // (X u> 13 & X s> 15) -> no change
859 case ICmpInst::ICMP_NE:
860 if (RHSCst == AddOne(LHSCst)) // (X u> 13 & X != 14) -> X u> 14
861 return Builder->CreateICmp(LHSCC, Val, RHSCst);
862 break; // (X u> 13 & X != 15) -> no change
863 case ICmpInst::ICMP_ULT: // (X u> 13 & X u< 15) -> (X-14) <u 1
864 return InsertRangeTest(Val, AddOne(LHSCst), RHSCst, false, true);
865 case ICmpInst::ICMP_SLT: // (X u> 13 & X s< 15) -> no change
869 case ICmpInst::ICMP_SGT:
871 default: llvm_unreachable("Unknown integer condition code!");
872 case ICmpInst::ICMP_EQ: // (X s> 13 & X == 15) -> X == 15
873 case ICmpInst::ICMP_SGT: // (X s> 13 & X s> 15) -> X s> 15
875 case ICmpInst::ICMP_UGT: // (X s> 13 & X u> 15) -> no change
877 case ICmpInst::ICMP_NE:
878 if (RHSCst == AddOne(LHSCst)) // (X s> 13 & X != 14) -> X s> 14
879 return Builder->CreateICmp(LHSCC, Val, RHSCst);
880 break; // (X s> 13 & X != 15) -> no change
881 case ICmpInst::ICMP_SLT: // (X s> 13 & X s< 15) -> (X-14) s< 1
882 return InsertRangeTest(Val, AddOne(LHSCst), RHSCst, true, true);
883 case ICmpInst::ICMP_ULT: // (X s> 13 & X u< 15) -> no change
892 /// FoldAndOfFCmps - Optimize (fcmp)&(fcmp). NOTE: Unlike the rest of
893 /// instcombine, this returns a Value which should already be inserted into the
895 Value *InstCombiner::FoldAndOfFCmps(FCmpInst *LHS, FCmpInst *RHS) {
896 if (LHS->getPredicate() == FCmpInst::FCMP_ORD &&
897 RHS->getPredicate() == FCmpInst::FCMP_ORD) {
898 // (fcmp ord x, c) & (fcmp ord y, c) -> (fcmp ord x, y)
899 if (ConstantFP *LHSC = dyn_cast<ConstantFP>(LHS->getOperand(1)))
900 if (ConstantFP *RHSC = dyn_cast<ConstantFP>(RHS->getOperand(1))) {
901 // If either of the constants are nans, then the whole thing returns
903 if (LHSC->getValueAPF().isNaN() || RHSC->getValueAPF().isNaN())
904 return ConstantInt::getFalse(LHS->getContext());
905 return Builder->CreateFCmpORD(LHS->getOperand(0), RHS->getOperand(0));
908 // Handle vector zeros. This occurs because the canonical form of
909 // "fcmp ord x,x" is "fcmp ord x, 0".
910 if (isa<ConstantAggregateZero>(LHS->getOperand(1)) &&
911 isa<ConstantAggregateZero>(RHS->getOperand(1)))
912 return Builder->CreateFCmpORD(LHS->getOperand(0), RHS->getOperand(0));
916 Value *Op0LHS = LHS->getOperand(0), *Op0RHS = LHS->getOperand(1);
917 Value *Op1LHS = RHS->getOperand(0), *Op1RHS = RHS->getOperand(1);
918 FCmpInst::Predicate Op0CC = LHS->getPredicate(), Op1CC = RHS->getPredicate();
921 if (Op0LHS == Op1RHS && Op0RHS == Op1LHS) {
922 // Swap RHS operands to match LHS.
923 Op1CC = FCmpInst::getSwappedPredicate(Op1CC);
924 std::swap(Op1LHS, Op1RHS);
927 if (Op0LHS == Op1LHS && Op0RHS == Op1RHS) {
928 // Simplify (fcmp cc0 x, y) & (fcmp cc1 x, y).
930 return Builder->CreateFCmp((FCmpInst::Predicate)Op0CC, Op0LHS, Op0RHS);
931 if (Op0CC == FCmpInst::FCMP_FALSE || Op1CC == FCmpInst::FCMP_FALSE)
932 return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
933 if (Op0CC == FCmpInst::FCMP_TRUE)
935 if (Op1CC == FCmpInst::FCMP_TRUE)
940 unsigned Op0Pred = getFCmpCode(Op0CC, Op0Ordered);
941 unsigned Op1Pred = getFCmpCode(Op1CC, Op1Ordered);
944 std::swap(Op0Pred, Op1Pred);
945 std::swap(Op0Ordered, Op1Ordered);
948 // uno && ueq -> uno && (uno || eq) -> ueq
949 // ord && olt -> ord && (ord && lt) -> olt
950 if (Op0Ordered == Op1Ordered)
953 // uno && oeq -> uno && (ord && eq) -> false
954 // uno && ord -> false
956 return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
957 // ord && ueq -> ord && (uno || eq) -> oeq
958 return getFCmpValue(true, Op1Pred, Op0LHS, Op0RHS, Builder);
966 Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
967 bool Changed = SimplifyCommutative(I);
968 Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
970 if (Value *V = SimplifyAndInst(Op0, Op1, TD))
971 return ReplaceInstUsesWith(I, V);
973 // See if we can simplify any instructions used by the instruction whose sole
974 // purpose is to compute bits we don't care about.
975 if (SimplifyDemandedInstructionBits(I))
978 if (ConstantInt *AndRHS = dyn_cast<ConstantInt>(Op1)) {
979 const APInt &AndRHSMask = AndRHS->getValue();
980 APInt NotAndRHS(~AndRHSMask);
982 // Optimize a variety of ((val OP C1) & C2) combinations...
983 if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0)) {
984 Value *Op0LHS = Op0I->getOperand(0);
985 Value *Op0RHS = Op0I->getOperand(1);
986 switch (Op0I->getOpcode()) {
988 case Instruction::Xor:
989 case Instruction::Or:
990 // If the mask is only needed on one incoming arm, push it up.
991 if (!Op0I->hasOneUse()) break;
993 if (MaskedValueIsZero(Op0LHS, NotAndRHS)) {
994 // Not masking anything out for the LHS, move to RHS.
995 Value *NewRHS = Builder->CreateAnd(Op0RHS, AndRHS,
996 Op0RHS->getName()+".masked");
997 return BinaryOperator::Create(Op0I->getOpcode(), Op0LHS, NewRHS);
999 if (!isa<Constant>(Op0RHS) &&
1000 MaskedValueIsZero(Op0RHS, NotAndRHS)) {
1001 // Not masking anything out for the RHS, move to LHS.
1002 Value *NewLHS = Builder->CreateAnd(Op0LHS, AndRHS,
1003 Op0LHS->getName()+".masked");
1004 return BinaryOperator::Create(Op0I->getOpcode(), NewLHS, Op0RHS);
1008 case Instruction::Add:
1009 // ((A & N) + B) & AndRHS -> (A + B) & AndRHS iff N&AndRHS == AndRHS.
1010 // ((A | N) + B) & AndRHS -> (A + B) & AndRHS iff N&AndRHS == 0
1011 // ((A ^ N) + B) & AndRHS -> (A + B) & AndRHS iff N&AndRHS == 0
1012 if (Value *V = FoldLogicalPlusAnd(Op0LHS, Op0RHS, AndRHS, false, I))
1013 return BinaryOperator::CreateAnd(V, AndRHS);
1014 if (Value *V = FoldLogicalPlusAnd(Op0RHS, Op0LHS, AndRHS, false, I))
1015 return BinaryOperator::CreateAnd(V, AndRHS); // Add commutes
1018 case Instruction::Sub:
1019 // ((A & N) - B) & AndRHS -> (A - B) & AndRHS iff N&AndRHS == AndRHS.
1020 // ((A | N) - B) & AndRHS -> (A - B) & AndRHS iff N&AndRHS == 0
1021 // ((A ^ N) - B) & AndRHS -> (A - B) & AndRHS iff N&AndRHS == 0
1022 if (Value *V = FoldLogicalPlusAnd(Op0LHS, Op0RHS, AndRHS, true, I))
1023 return BinaryOperator::CreateAnd(V, AndRHS);
1025 // (A - N) & AndRHS -> -N & AndRHS iff A&AndRHS==0 and AndRHS
1026 // has 1's for all bits that the subtraction with A might affect.
1027 if (Op0I->hasOneUse()) {
1028 uint32_t BitWidth = AndRHSMask.getBitWidth();
1029 uint32_t Zeros = AndRHSMask.countLeadingZeros();
1030 APInt Mask = APInt::getLowBitsSet(BitWidth, BitWidth - Zeros);
1032 ConstantInt *A = dyn_cast<ConstantInt>(Op0LHS);
1033 if (!(A && A->isZero()) && // avoid infinite recursion.
1034 MaskedValueIsZero(Op0LHS, Mask)) {
1035 Value *NewNeg = Builder->CreateNeg(Op0RHS);
1036 return BinaryOperator::CreateAnd(NewNeg, AndRHS);
1041 case Instruction::Shl:
1042 case Instruction::LShr:
1043 // (1 << x) & 1 --> zext(x == 0)
1044 // (1 >> x) & 1 --> zext(x == 0)
1045 if (AndRHSMask == 1 && Op0LHS == AndRHS) {
1047 Builder->CreateICmpEQ(Op0RHS, Constant::getNullValue(I.getType()));
1048 return new ZExtInst(NewICmp, I.getType());
1053 if (ConstantInt *Op0CI = dyn_cast<ConstantInt>(Op0I->getOperand(1)))
1054 if (Instruction *Res = OptAndOp(Op0I, Op0CI, AndRHS, I))
1056 } else if (CastInst *CI = dyn_cast<CastInst>(Op0)) {
1057 // If this is an integer truncation or change from signed-to-unsigned, and
1058 // if the source is an and/or with immediate, transform it. This
1059 // frequently occurs for bitfield accesses.
1060 if (Instruction *CastOp = dyn_cast<Instruction>(CI->getOperand(0))) {
1061 if ((isa<TruncInst>(CI) || isa<BitCastInst>(CI)) &&
1062 CastOp->getNumOperands() == 2)
1063 if (ConstantInt *AndCI =dyn_cast<ConstantInt>(CastOp->getOperand(1))){
1064 if (CastOp->getOpcode() == Instruction::And) {
1065 // Change: and (cast (and X, C1) to T), C2
1066 // into : and (cast X to T), trunc_or_bitcast(C1)&C2
1067 // This will fold the two constants together, which may allow
1068 // other simplifications.
1069 Value *NewCast = Builder->CreateTruncOrBitCast(
1070 CastOp->getOperand(0), I.getType(),
1071 CastOp->getName()+".shrunk");
1072 // trunc_or_bitcast(C1)&C2
1073 Constant *C3 = ConstantExpr::getTruncOrBitCast(AndCI,I.getType());
1074 C3 = ConstantExpr::getAnd(C3, AndRHS);
1075 return BinaryOperator::CreateAnd(NewCast, C3);
1076 } else if (CastOp->getOpcode() == Instruction::Or) {
1077 // Change: and (cast (or X, C1) to T), C2
1078 // into : trunc(C1)&C2 iff trunc(C1)&C2 == C2
1079 Constant *C3 = ConstantExpr::getTruncOrBitCast(AndCI,I.getType());
1080 if (ConstantExpr::getAnd(C3, AndRHS) == AndRHS)
1082 return ReplaceInstUsesWith(I, AndRHS);
1088 // Try to fold constant and into select arguments.
1089 if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
1090 if (Instruction *R = FoldOpIntoSelect(I, SI))
1092 if (isa<PHINode>(Op0))
1093 if (Instruction *NV = FoldOpIntoPhi(I))
1098 // (~A & ~B) == (~(A | B)) - De Morgan's Law
1099 if (Value *Op0NotVal = dyn_castNotVal(Op0))
1100 if (Value *Op1NotVal = dyn_castNotVal(Op1))
1101 if (Op0->hasOneUse() && Op1->hasOneUse()) {
1102 Value *Or = Builder->CreateOr(Op0NotVal, Op1NotVal,
1103 I.getName()+".demorgan");
1104 return BinaryOperator::CreateNot(Or);
1108 Value *A = 0, *B = 0, *C = 0, *D = 0;
1109 // (A|B) & ~(A&B) -> A^B
1110 if (match(Op0, m_Or(m_Value(A), m_Value(B))) &&
1111 match(Op1, m_Not(m_And(m_Value(C), m_Value(D)))) &&
1112 ((A == C && B == D) || (A == D && B == C)))
1113 return BinaryOperator::CreateXor(A, B);
1115 // ~(A&B) & (A|B) -> A^B
1116 if (match(Op1, m_Or(m_Value(A), m_Value(B))) &&
1117 match(Op0, m_Not(m_And(m_Value(C), m_Value(D)))) &&
1118 ((A == C && B == D) || (A == D && B == C)))
1119 return BinaryOperator::CreateXor(A, B);
1121 if (Op0->hasOneUse() &&
1122 match(Op0, m_Xor(m_Value(A), m_Value(B)))) {
1123 if (A == Op1) { // (A^B)&A -> A&(A^B)
1124 I.swapOperands(); // Simplify below
1125 std::swap(Op0, Op1);
1126 } else if (B == Op1) { // (A^B)&B -> B&(B^A)
1127 cast<BinaryOperator>(Op0)->swapOperands();
1128 I.swapOperands(); // Simplify below
1129 std::swap(Op0, Op1);
1133 if (Op1->hasOneUse() &&
1134 match(Op1, m_Xor(m_Value(A), m_Value(B)))) {
1135 if (B == Op0) { // B&(A^B) -> B&(B^A)
1136 cast<BinaryOperator>(Op1)->swapOperands();
1139 if (A == Op0) // A&(A^B) -> A & ~B
1140 return BinaryOperator::CreateAnd(A, Builder->CreateNot(B, "tmp"));
1143 // (A&((~A)|B)) -> A&B
1144 if (match(Op0, m_Or(m_Not(m_Specific(Op1)), m_Value(A))) ||
1145 match(Op0, m_Or(m_Value(A), m_Not(m_Specific(Op1)))))
1146 return BinaryOperator::CreateAnd(A, Op1);
1147 if (match(Op1, m_Or(m_Not(m_Specific(Op0)), m_Value(A))) ||
1148 match(Op1, m_Or(m_Value(A), m_Not(m_Specific(Op0)))))
1149 return BinaryOperator::CreateAnd(A, Op0);
1152 if (ICmpInst *RHS = dyn_cast<ICmpInst>(Op1))
1153 if (ICmpInst *LHS = dyn_cast<ICmpInst>(Op0))
1154 if (Value *Res = FoldAndOfICmps(LHS, RHS))
1155 return ReplaceInstUsesWith(I, Res);
1157 // If and'ing two fcmp, try combine them into one.
1158 if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0)))
1159 if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
1160 if (Value *Res = FoldAndOfFCmps(LHS, RHS))
1161 return ReplaceInstUsesWith(I, Res);
1164 // fold (and (cast A), (cast B)) -> (cast (and A, B))
1165 if (CastInst *Op0C = dyn_cast<CastInst>(Op0))
1166 if (CastInst *Op1C = dyn_cast<CastInst>(Op1)) {
1167 const Type *SrcTy = Op0C->getOperand(0)->getType();
1168 if (Op0C->getOpcode() == Op1C->getOpcode() && // same cast kind ?
1169 SrcTy == Op1C->getOperand(0)->getType() &&
1170 SrcTy->isIntOrIntVectorTy()) {
1171 Value *Op0COp = Op0C->getOperand(0), *Op1COp = Op1C->getOperand(0);
1173 // Only do this if the casts both really cause code to be generated.
1174 if (ShouldOptimizeCast(Op0C->getOpcode(), Op0COp, I.getType()) &&
1175 ShouldOptimizeCast(Op1C->getOpcode(), Op1COp, I.getType())) {
1176 Value *NewOp = Builder->CreateAnd(Op0COp, Op1COp, I.getName());
1177 return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType());
1180 // If this is and(cast(icmp), cast(icmp)), try to fold this even if the
1181 // cast is otherwise not optimizable. This happens for vector sexts.
1182 if (ICmpInst *RHS = dyn_cast<ICmpInst>(Op1COp))
1183 if (ICmpInst *LHS = dyn_cast<ICmpInst>(Op0COp))
1184 if (Value *Res = FoldAndOfICmps(LHS, RHS))
1185 return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
1187 // If this is and(cast(fcmp), cast(fcmp)), try to fold this even if the
1188 // cast is otherwise not optimizable. This happens for vector sexts.
1189 if (FCmpInst *RHS = dyn_cast<FCmpInst>(Op1COp))
1190 if (FCmpInst *LHS = dyn_cast<FCmpInst>(Op0COp))
1191 if (Value *Res = FoldAndOfFCmps(LHS, RHS))
1192 return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
1196 // (X >> Z) & (Y >> Z) -> (X&Y) >> Z for all shifts.
1197 if (BinaryOperator *SI1 = dyn_cast<BinaryOperator>(Op1)) {
1198 if (BinaryOperator *SI0 = dyn_cast<BinaryOperator>(Op0))
1199 if (SI0->isShift() && SI0->getOpcode() == SI1->getOpcode() &&
1200 SI0->getOperand(1) == SI1->getOperand(1) &&
1201 (SI0->hasOneUse() || SI1->hasOneUse())) {
1203 Builder->CreateAnd(SI0->getOperand(0), SI1->getOperand(0),
1205 return BinaryOperator::Create(SI1->getOpcode(), NewOp,
1206 SI1->getOperand(1));
1210 return Changed ? &I : 0;
1213 /// CollectBSwapParts - Analyze the specified subexpression and see if it is
1214 /// capable of providing pieces of a bswap. The subexpression provides pieces
1215 /// of a bswap if it is proven that each of the non-zero bytes in the output of
1216 /// the expression came from the corresponding "byte swapped" byte in some other
1217 /// value. For example, if the current subexpression is "(shl i32 %X, 24)" then
1218 /// we know that the expression deposits the low byte of %X into the high byte
1219 /// of the bswap result and that all other bytes are zero. This expression is
1220 /// accepted, the high byte of ByteValues is set to X to indicate a correct
1223 /// This function returns true if the match was unsuccessful and false if so.
1224 /// On entry to the function the "OverallLeftShift" is a signed integer value
1225 /// indicating the number of bytes that the subexpression is later shifted. For
1226 /// example, if the expression is later right shifted by 16 bits, the
1227 /// OverallLeftShift value would be -2 on entry. This is used to specify which
1228 /// byte of ByteValues is actually being set.
1230 /// Similarly, ByteMask is a bitmask where a bit is clear if its corresponding
1231 /// byte is masked to zero by a user. For example, in (X & 255), X will be
1232 /// processed with a bytemask of 1. Because bytemask is 32-bits, this limits
1233 /// this function to working on up to 32-byte (256 bit) values. ByteMask is
1234 /// always in the local (OverallLeftShift) coordinate space.
1236 static bool CollectBSwapParts(Value *V, int OverallLeftShift, uint32_t ByteMask,
1237 SmallVector<Value*, 8> &ByteValues) {
1238 if (Instruction *I = dyn_cast<Instruction>(V)) {
1239 // If this is an or instruction, it may be an inner node of the bswap.
1240 if (I->getOpcode() == Instruction::Or) {
1241 return CollectBSwapParts(I->getOperand(0), OverallLeftShift, ByteMask,
1243 CollectBSwapParts(I->getOperand(1), OverallLeftShift, ByteMask,
1247 // If this is a logical shift by a constant multiple of 8, recurse with
1248 // OverallLeftShift and ByteMask adjusted.
1249 if (I->isLogicalShift() && isa<ConstantInt>(I->getOperand(1))) {
1251 cast<ConstantInt>(I->getOperand(1))->getLimitedValue(~0U);
1252 // Ensure the shift amount is defined and of a byte value.
1253 if ((ShAmt & 7) || (ShAmt > 8*ByteValues.size()))
1256 unsigned ByteShift = ShAmt >> 3;
1257 if (I->getOpcode() == Instruction::Shl) {
1258 // X << 2 -> collect(X, +2)
1259 OverallLeftShift += ByteShift;
1260 ByteMask >>= ByteShift;
1262 // X >>u 2 -> collect(X, -2)
1263 OverallLeftShift -= ByteShift;
1264 ByteMask <<= ByteShift;
1265 ByteMask &= (~0U >> (32-ByteValues.size()));
1268 if (OverallLeftShift >= (int)ByteValues.size()) return true;
1269 if (OverallLeftShift <= -(int)ByteValues.size()) return true;
1271 return CollectBSwapParts(I->getOperand(0), OverallLeftShift, ByteMask,
1275 // If this is a logical 'and' with a mask that clears bytes, clear the
1276 // corresponding bytes in ByteMask.
1277 if (I->getOpcode() == Instruction::And &&
1278 isa<ConstantInt>(I->getOperand(1))) {
1279 // Scan every byte of the and mask, seeing if the byte is either 0 or 255.
1280 unsigned NumBytes = ByteValues.size();
1281 APInt Byte(I->getType()->getPrimitiveSizeInBits(), 255);
1282 const APInt &AndMask = cast<ConstantInt>(I->getOperand(1))->getValue();
1284 for (unsigned i = 0; i != NumBytes; ++i, Byte <<= 8) {
1285 // If this byte is masked out by a later operation, we don't care what
1287 if ((ByteMask & (1 << i)) == 0)
1290 // If the AndMask is all zeros for this byte, clear the bit.
1291 APInt MaskB = AndMask & Byte;
1293 ByteMask &= ~(1U << i);
1297 // If the AndMask is not all ones for this byte, it's not a bytezap.
1301 // Otherwise, this byte is kept.
1304 return CollectBSwapParts(I->getOperand(0), OverallLeftShift, ByteMask,
1309 // Okay, we got to something that isn't a shift, 'or' or 'and'. This must be
1310 // the input value to the bswap. Some observations: 1) if more than one byte
1311 // is demanded from this input, then it could not be successfully assembled
1312 // into a byteswap. At least one of the two bytes would not be aligned with
1313 // their ultimate destination.
1314 if (!isPowerOf2_32(ByteMask)) return true;
1315 unsigned InputByteNo = CountTrailingZeros_32(ByteMask);
1317 // 2) The input and ultimate destinations must line up: if byte 3 of an i32
1318 // is demanded, it needs to go into byte 0 of the result. This means that the
1319 // byte needs to be shifted until it lands in the right byte bucket. The
1320 // shift amount depends on the position: if the byte is coming from the high
1321 // part of the value (e.g. byte 3) then it must be shifted right. If from the
1322 // low part, it must be shifted left.
1323 unsigned DestByteNo = InputByteNo + OverallLeftShift;
1324 if (InputByteNo < ByteValues.size()/2) {
1325 if (ByteValues.size()-1-DestByteNo != InputByteNo)
1328 if (ByteValues.size()-1-DestByteNo != InputByteNo)
1332 // If the destination byte value is already defined, the values are or'd
1333 // together, which isn't a bswap (unless it's an or of the same bits).
1334 if (ByteValues[DestByteNo] && ByteValues[DestByteNo] != V)
1336 ByteValues[DestByteNo] = V;
1340 /// MatchBSwap - Given an OR instruction, check to see if this is a bswap idiom.
1341 /// If so, insert the new bswap intrinsic and return it.
1342 Instruction *InstCombiner::MatchBSwap(BinaryOperator &I) {
1343 const IntegerType *ITy = dyn_cast<IntegerType>(I.getType());
1344 if (!ITy || ITy->getBitWidth() % 16 ||
1345 // ByteMask only allows up to 32-byte values.
1346 ITy->getBitWidth() > 32*8)
1347 return 0; // Can only bswap pairs of bytes. Can't do vectors.
1349 /// ByteValues - For each byte of the result, we keep track of which value
1350 /// defines each byte.
1351 SmallVector<Value*, 8> ByteValues;
1352 ByteValues.resize(ITy->getBitWidth()/8);
1354 // Try to find all the pieces corresponding to the bswap.
1355 uint32_t ByteMask = ~0U >> (32-ByteValues.size());
1356 if (CollectBSwapParts(&I, 0, ByteMask, ByteValues))
1359 // Check to see if all of the bytes come from the same value.
1360 Value *V = ByteValues[0];
1361 if (V == 0) return 0; // Didn't find a byte? Must be zero.
1363 // Check to make sure that all of the bytes come from the same value.
1364 for (unsigned i = 1, e = ByteValues.size(); i != e; ++i)
1365 if (ByteValues[i] != V)
1367 const Type *Tys[] = { ITy };
1368 Module *M = I.getParent()->getParent()->getParent();
1369 Function *F = Intrinsic::getDeclaration(M, Intrinsic::bswap, Tys, 1);
1370 return CallInst::Create(F, V);
1373 /// MatchSelectFromAndOr - We have an expression of the form (A&C)|(B&D). Check
1374 /// If A is (cond?-1:0) and either B or D is ~(cond?-1,0) or (cond?0,-1), then
1375 /// we can simplify this expression to "cond ? C : D or B".
1376 static Instruction *MatchSelectFromAndOr(Value *A, Value *B,
1377 Value *C, Value *D) {
1378 // If A is not a select of -1/0, this cannot match.
1380 if (!match(A, m_SExt(m_Value(Cond))) ||
1381 !Cond->getType()->isIntegerTy(1))
1384 // ((cond?-1:0)&C) | (B&(cond?0:-1)) -> cond ? C : B.
1385 if (match(D, m_Not(m_SExt(m_Specific(Cond)))))
1386 return SelectInst::Create(Cond, C, B);
1387 if (match(D, m_SExt(m_Not(m_Specific(Cond)))))
1388 return SelectInst::Create(Cond, C, B);
1390 // ((cond?-1:0)&C) | ((cond?0:-1)&D) -> cond ? C : D.
1391 if (match(B, m_Not(m_SExt(m_Specific(Cond)))))
1392 return SelectInst::Create(Cond, C, D);
1393 if (match(B, m_SExt(m_Not(m_Specific(Cond)))))
1394 return SelectInst::Create(Cond, C, D);
1398 /// FoldOrOfICmps - Fold (icmp)|(icmp) if possible.
1399 Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
1400 ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate();
1402 // (icmp1 A, B) | (icmp2 A, B) --> (icmp3 A, B)
1403 if (PredicatesFoldable(LHSCC, RHSCC)) {
1404 if (LHS->getOperand(0) == RHS->getOperand(1) &&
1405 LHS->getOperand(1) == RHS->getOperand(0))
1406 LHS->swapOperands();
1407 if (LHS->getOperand(0) == RHS->getOperand(0) &&
1408 LHS->getOperand(1) == RHS->getOperand(1)) {
1409 Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
1410 unsigned Code = getICmpCode(LHS) | getICmpCode(RHS);
1411 bool isSigned = LHS->isSigned() || RHS->isSigned();
1412 return getICmpValue(isSigned, Code, Op0, Op1, Builder);
1417 // handle (roughly):
1418 // (icmp ne (A & B), C) | (icmp ne (A & D), E)
1419 Value* fold = foldLogOpOfMaskedICmps(LHS, RHS, ICmpInst::ICMP_NE, Builder);
1420 if (fold) return fold;
1423 // This only handles icmp of constants: (icmp1 A, C1) | (icmp2 B, C2).
1424 Value *Val = LHS->getOperand(0), *Val2 = RHS->getOperand(0);
1425 ConstantInt *LHSCst = dyn_cast<ConstantInt>(LHS->getOperand(1));
1426 ConstantInt *RHSCst = dyn_cast<ConstantInt>(RHS->getOperand(1));
1427 if (LHSCst == 0 || RHSCst == 0) return 0;
1429 if (LHSCst == RHSCst && LHSCC == RHSCC) {
1430 // (icmp ne A, 0) | (icmp ne B, 0) --> (icmp ne (A|B), 0)
1431 if (LHSCC == ICmpInst::ICMP_NE && LHSCst->isZero()) {
1432 Value *NewOr = Builder->CreateOr(Val, Val2);
1433 return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
1437 // From here on, we only handle:
1438 // (icmp1 A, C1) | (icmp2 A, C2) --> something simpler.
1439 if (Val != Val2) return 0;
1441 // ICMP_[US][GL]E X, CST is folded to ICMP_[US][GL]T elsewhere.
1442 if (LHSCC == ICmpInst::ICMP_UGE || LHSCC == ICmpInst::ICMP_ULE ||
1443 RHSCC == ICmpInst::ICMP_UGE || RHSCC == ICmpInst::ICMP_ULE ||
1444 LHSCC == ICmpInst::ICMP_SGE || LHSCC == ICmpInst::ICMP_SLE ||
1445 RHSCC == ICmpInst::ICMP_SGE || RHSCC == ICmpInst::ICMP_SLE)
1448 // We can't fold (ugt x, C) | (sgt x, C2).
1449 if (!PredicatesFoldable(LHSCC, RHSCC))
1452 // Ensure that the larger constant is on the RHS.
1454 if (CmpInst::isSigned(LHSCC) ||
1455 (ICmpInst::isEquality(LHSCC) &&
1456 CmpInst::isSigned(RHSCC)))
1457 ShouldSwap = LHSCst->getValue().sgt(RHSCst->getValue());
1459 ShouldSwap = LHSCst->getValue().ugt(RHSCst->getValue());
1462 std::swap(LHS, RHS);
1463 std::swap(LHSCst, RHSCst);
1464 std::swap(LHSCC, RHSCC);
1467 // At this point, we know we have two icmp instructions
1468 // comparing a value against two constants and or'ing the result
1469 // together. Because of the above check, we know that we only have
1470 // ICMP_EQ, ICMP_NE, ICMP_LT, and ICMP_GT here. We also know (from the
1471 // icmp folding check above), that the two constants are not
1473 assert(LHSCst != RHSCst && "Compares not folded above?");
1476 default: llvm_unreachable("Unknown integer condition code!");
1477 case ICmpInst::ICMP_EQ:
1479 default: llvm_unreachable("Unknown integer condition code!");
1480 case ICmpInst::ICMP_EQ:
1481 if (LHSCst == SubOne(RHSCst)) {
1482 // (X == 13 | X == 14) -> X-13 <u 2
1483 Constant *AddCST = ConstantExpr::getNeg(LHSCst);
1484 Value *Add = Builder->CreateAdd(Val, AddCST, Val->getName()+".off");
1485 AddCST = ConstantExpr::getSub(AddOne(RHSCst), LHSCst);
1486 return Builder->CreateICmpULT(Add, AddCST);
1488 break; // (X == 13 | X == 15) -> no change
1489 case ICmpInst::ICMP_UGT: // (X == 13 | X u> 14) -> no change
1490 case ICmpInst::ICMP_SGT: // (X == 13 | X s> 14) -> no change
1492 case ICmpInst::ICMP_NE: // (X == 13 | X != 15) -> X != 15
1493 case ICmpInst::ICMP_ULT: // (X == 13 | X u< 15) -> X u< 15
1494 case ICmpInst::ICMP_SLT: // (X == 13 | X s< 15) -> X s< 15
1498 case ICmpInst::ICMP_NE:
1500 default: llvm_unreachable("Unknown integer condition code!");
1501 case ICmpInst::ICMP_EQ: // (X != 13 | X == 15) -> X != 13
1502 case ICmpInst::ICMP_UGT: // (X != 13 | X u> 15) -> X != 13
1503 case ICmpInst::ICMP_SGT: // (X != 13 | X s> 15) -> X != 13
1505 case ICmpInst::ICMP_NE: // (X != 13 | X != 15) -> true
1506 case ICmpInst::ICMP_ULT: // (X != 13 | X u< 15) -> true
1507 case ICmpInst::ICMP_SLT: // (X != 13 | X s< 15) -> true
1508 return ConstantInt::getTrue(LHS->getContext());
1511 case ICmpInst::ICMP_ULT:
1513 default: llvm_unreachable("Unknown integer condition code!");
1514 case ICmpInst::ICMP_EQ: // (X u< 13 | X == 14) -> no change
1516 case ICmpInst::ICMP_UGT: // (X u< 13 | X u> 15) -> (X-13) u> 2
1517 // If RHSCst is [us]MAXINT, it is always false. Not handling
1518 // this can cause overflow.
1519 if (RHSCst->isMaxValue(false))
1521 return InsertRangeTest(Val, LHSCst, AddOne(RHSCst), false, false);
1522 case ICmpInst::ICMP_SGT: // (X u< 13 | X s> 15) -> no change
1524 case ICmpInst::ICMP_NE: // (X u< 13 | X != 15) -> X != 15
1525 case ICmpInst::ICMP_ULT: // (X u< 13 | X u< 15) -> X u< 15
1527 case ICmpInst::ICMP_SLT: // (X u< 13 | X s< 15) -> no change
1531 case ICmpInst::ICMP_SLT:
1533 default: llvm_unreachable("Unknown integer condition code!");
1534 case ICmpInst::ICMP_EQ: // (X s< 13 | X == 14) -> no change
1536 case ICmpInst::ICMP_SGT: // (X s< 13 | X s> 15) -> (X-13) s> 2
1537 // If RHSCst is [us]MAXINT, it is always false. Not handling
1538 // this can cause overflow.
1539 if (RHSCst->isMaxValue(true))
1541 return InsertRangeTest(Val, LHSCst, AddOne(RHSCst), true, false);
1542 case ICmpInst::ICMP_UGT: // (X s< 13 | X u> 15) -> no change
1544 case ICmpInst::ICMP_NE: // (X s< 13 | X != 15) -> X != 15
1545 case ICmpInst::ICMP_SLT: // (X s< 13 | X s< 15) -> X s< 15
1547 case ICmpInst::ICMP_ULT: // (X s< 13 | X u< 15) -> no change
1551 case ICmpInst::ICMP_UGT:
1553 default: llvm_unreachable("Unknown integer condition code!");
1554 case ICmpInst::ICMP_EQ: // (X u> 13 | X == 15) -> X u> 13
1555 case ICmpInst::ICMP_UGT: // (X u> 13 | X u> 15) -> X u> 13
1557 case ICmpInst::ICMP_SGT: // (X u> 13 | X s> 15) -> no change
1559 case ICmpInst::ICMP_NE: // (X u> 13 | X != 15) -> true
1560 case ICmpInst::ICMP_ULT: // (X u> 13 | X u< 15) -> true
1561 return ConstantInt::getTrue(LHS->getContext());
1562 case ICmpInst::ICMP_SLT: // (X u> 13 | X s< 15) -> no change
1566 case ICmpInst::ICMP_SGT:
1568 default: llvm_unreachable("Unknown integer condition code!");
1569 case ICmpInst::ICMP_EQ: // (X s> 13 | X == 15) -> X > 13
1570 case ICmpInst::ICMP_SGT: // (X s> 13 | X s> 15) -> X > 13
1572 case ICmpInst::ICMP_UGT: // (X s> 13 | X u> 15) -> no change
1574 case ICmpInst::ICMP_NE: // (X s> 13 | X != 15) -> true
1575 case ICmpInst::ICMP_SLT: // (X s> 13 | X s< 15) -> true
1576 return ConstantInt::getTrue(LHS->getContext());
1577 case ICmpInst::ICMP_ULT: // (X s> 13 | X u< 15) -> no change
1585 /// FoldOrOfFCmps - Optimize (fcmp)|(fcmp). NOTE: Unlike the rest of
1586 /// instcombine, this returns a Value which should already be inserted into the
1588 Value *InstCombiner::FoldOrOfFCmps(FCmpInst *LHS, FCmpInst *RHS) {
1589 if (LHS->getPredicate() == FCmpInst::FCMP_UNO &&
1590 RHS->getPredicate() == FCmpInst::FCMP_UNO &&
1591 LHS->getOperand(0)->getType() == RHS->getOperand(0)->getType()) {
1592 if (ConstantFP *LHSC = dyn_cast<ConstantFP>(LHS->getOperand(1)))
1593 if (ConstantFP *RHSC = dyn_cast<ConstantFP>(RHS->getOperand(1))) {
1594 // If either of the constants are nans, then the whole thing returns
1596 if (LHSC->getValueAPF().isNaN() || RHSC->getValueAPF().isNaN())
1597 return ConstantInt::getTrue(LHS->getContext());
1599 // Otherwise, no need to compare the two constants, compare the
1601 return Builder->CreateFCmpUNO(LHS->getOperand(0), RHS->getOperand(0));
1604 // Handle vector zeros. This occurs because the canonical form of
1605 // "fcmp uno x,x" is "fcmp uno x, 0".
1606 if (isa<ConstantAggregateZero>(LHS->getOperand(1)) &&
1607 isa<ConstantAggregateZero>(RHS->getOperand(1)))
1608 return Builder->CreateFCmpUNO(LHS->getOperand(0), RHS->getOperand(0));
1613 Value *Op0LHS = LHS->getOperand(0), *Op0RHS = LHS->getOperand(1);
1614 Value *Op1LHS = RHS->getOperand(0), *Op1RHS = RHS->getOperand(1);
1615 FCmpInst::Predicate Op0CC = LHS->getPredicate(), Op1CC = RHS->getPredicate();
1617 if (Op0LHS == Op1RHS && Op0RHS == Op1LHS) {
1618 // Swap RHS operands to match LHS.
1619 Op1CC = FCmpInst::getSwappedPredicate(Op1CC);
1620 std::swap(Op1LHS, Op1RHS);
1622 if (Op0LHS == Op1LHS && Op0RHS == Op1RHS) {
1623 // Simplify (fcmp cc0 x, y) | (fcmp cc1 x, y).
1625 return Builder->CreateFCmp((FCmpInst::Predicate)Op0CC, Op0LHS, Op0RHS);
1626 if (Op0CC == FCmpInst::FCMP_TRUE || Op1CC == FCmpInst::FCMP_TRUE)
1627 return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 1);
1628 if (Op0CC == FCmpInst::FCMP_FALSE)
1630 if (Op1CC == FCmpInst::FCMP_FALSE)
1634 unsigned Op0Pred = getFCmpCode(Op0CC, Op0Ordered);
1635 unsigned Op1Pred = getFCmpCode(Op1CC, Op1Ordered);
1636 if (Op0Ordered == Op1Ordered) {
1637 // If both are ordered or unordered, return a new fcmp with
1638 // or'ed predicates.
1639 return getFCmpValue(Op0Ordered, Op0Pred|Op1Pred, Op0LHS, Op0RHS, Builder);
1645 /// FoldOrWithConstants - This helper function folds:
1647 /// ((A | B) & C1) | (B & C2)
1653 /// when the XOR of the two constants is "all ones" (-1).
1654 Instruction *InstCombiner::FoldOrWithConstants(BinaryOperator &I, Value *Op,
1655 Value *A, Value *B, Value *C) {
1656 ConstantInt *CI1 = dyn_cast<ConstantInt>(C);
1660 ConstantInt *CI2 = 0;
1661 if (!match(Op, m_And(m_Value(V1), m_ConstantInt(CI2)))) return 0;
1663 APInt Xor = CI1->getValue() ^ CI2->getValue();
1664 if (!Xor.isAllOnesValue()) return 0;
1666 if (V1 == A || V1 == B) {
1667 Value *NewOp = Builder->CreateAnd((V1 == A) ? B : A, CI1);
1668 return BinaryOperator::CreateOr(NewOp, V1);
1674 Instruction *InstCombiner::visitOr(BinaryOperator &I) {
1675 bool Changed = SimplifyCommutative(I);
1676 Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
1678 if (Value *V = SimplifyOrInst(Op0, Op1, TD))
1679 return ReplaceInstUsesWith(I, V);
1681 // See if we can simplify any instructions used by the instruction whose sole
1682 // purpose is to compute bits we don't care about.
1683 if (SimplifyDemandedInstructionBits(I))
1686 if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) {
1687 ConstantInt *C1 = 0; Value *X = 0;
1688 // (X & C1) | C2 --> (X | C2) & (C1|C2)
1689 // iff (C1 & C2) == 0.
1690 if (match(Op0, m_And(m_Value(X), m_ConstantInt(C1))) &&
1691 (RHS->getValue() & C1->getValue()) != 0 &&
1693 Value *Or = Builder->CreateOr(X, RHS);
1695 return BinaryOperator::CreateAnd(Or,
1696 ConstantInt::get(I.getContext(),
1697 RHS->getValue() | C1->getValue()));
1700 // (X ^ C1) | C2 --> (X | C2) ^ (C1&~C2)
1701 if (match(Op0, m_Xor(m_Value(X), m_ConstantInt(C1))) &&
1703 Value *Or = Builder->CreateOr(X, RHS);
1705 return BinaryOperator::CreateXor(Or,
1706 ConstantInt::get(I.getContext(),
1707 C1->getValue() & ~RHS->getValue()));
1710 // Try to fold constant and into select arguments.
1711 if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
1712 if (Instruction *R = FoldOpIntoSelect(I, SI))
1715 if (isa<PHINode>(Op0))
1716 if (Instruction *NV = FoldOpIntoPhi(I))
1720 Value *A = 0, *B = 0;
1721 ConstantInt *C1 = 0, *C2 = 0;
1723 // (A | B) | C and A | (B | C) -> bswap if possible.
1724 // (A >> B) | (C << D) and (A << B) | (B >> C) -> bswap if possible.
1725 if (match(Op0, m_Or(m_Value(), m_Value())) ||
1726 match(Op1, m_Or(m_Value(), m_Value())) ||
1727 (match(Op0, m_Shift(m_Value(), m_Value())) &&
1728 match(Op1, m_Shift(m_Value(), m_Value())))) {
1729 if (Instruction *BSwap = MatchBSwap(I))
1733 // (X^C)|Y -> (X|Y)^C iff Y&C == 0
1734 if (Op0->hasOneUse() &&
1735 match(Op0, m_Xor(m_Value(A), m_ConstantInt(C1))) &&
1736 MaskedValueIsZero(Op1, C1->getValue())) {
1737 Value *NOr = Builder->CreateOr(A, Op1);
1739 return BinaryOperator::CreateXor(NOr, C1);
1742 // Y|(X^C) -> (X|Y)^C iff Y&C == 0
1743 if (Op1->hasOneUse() &&
1744 match(Op1, m_Xor(m_Value(A), m_ConstantInt(C1))) &&
1745 MaskedValueIsZero(Op0, C1->getValue())) {
1746 Value *NOr = Builder->CreateOr(A, Op0);
1748 return BinaryOperator::CreateXor(NOr, C1);
1752 Value *C = 0, *D = 0;
1753 if (match(Op0, m_And(m_Value(A), m_Value(C))) &&
1754 match(Op1, m_And(m_Value(B), m_Value(D)))) {
1755 Value *V1 = 0, *V2 = 0, *V3 = 0;
1756 C1 = dyn_cast<ConstantInt>(C);
1757 C2 = dyn_cast<ConstantInt>(D);
1758 if (C1 && C2) { // (A & C1)|(B & C2)
1759 // If we have: ((V + N) & C1) | (V & C2)
1760 // .. and C2 = ~C1 and C2 is 0+1+ and (N & C2) == 0
1761 // replace with V+N.
1762 if (C1->getValue() == ~C2->getValue()) {
1763 if ((C2->getValue() & (C2->getValue()+1)) == 0 && // C2 == 0+1+
1764 match(A, m_Add(m_Value(V1), m_Value(V2)))) {
1765 // Add commutes, try both ways.
1766 if (V1 == B && MaskedValueIsZero(V2, C2->getValue()))
1767 return ReplaceInstUsesWith(I, A);
1768 if (V2 == B && MaskedValueIsZero(V1, C2->getValue()))
1769 return ReplaceInstUsesWith(I, A);
1771 // Or commutes, try both ways.
1772 if ((C1->getValue() & (C1->getValue()+1)) == 0 &&
1773 match(B, m_Add(m_Value(V1), m_Value(V2)))) {
1774 // Add commutes, try both ways.
1775 if (V1 == A && MaskedValueIsZero(V2, C1->getValue()))
1776 return ReplaceInstUsesWith(I, B);
1777 if (V2 == A && MaskedValueIsZero(V1, C1->getValue()))
1778 return ReplaceInstUsesWith(I, B);
1782 if ((C1->getValue() & C2->getValue()) == 0) {
1783 // ((V | N) & C1) | (V & C2) --> (V|N) & (C1|C2)
1784 // iff (C1&C2) == 0 and (N&~C1) == 0
1785 if (match(A, m_Or(m_Value(V1), m_Value(V2))) &&
1786 ((V1 == B && MaskedValueIsZero(V2, ~C1->getValue())) || // (V|N)
1787 (V2 == B && MaskedValueIsZero(V1, ~C1->getValue())))) // (N|V)
1788 return BinaryOperator::CreateAnd(A,
1789 ConstantInt::get(A->getContext(),
1790 C1->getValue()|C2->getValue()));
1791 // Or commutes, try both ways.
1792 if (match(B, m_Or(m_Value(V1), m_Value(V2))) &&
1793 ((V1 == A && MaskedValueIsZero(V2, ~C2->getValue())) || // (V|N)
1794 (V2 == A && MaskedValueIsZero(V1, ~C2->getValue())))) // (N|V)
1795 return BinaryOperator::CreateAnd(B,
1796 ConstantInt::get(B->getContext(),
1797 C1->getValue()|C2->getValue()));
1799 // ((V|C3)&C1) | ((V|C4)&C2) --> (V|C3|C4)&(C1|C2)
1800 // iff (C1&C2) == 0 and (C3&~C1) == 0 and (C4&~C2) == 0.
1801 ConstantInt *C3 = 0, *C4 = 0;
1802 if (match(A, m_Or(m_Value(V1), m_ConstantInt(C3))) &&
1803 (C3->getValue() & ~C1->getValue()) == 0 &&
1804 match(B, m_Or(m_Specific(V1), m_ConstantInt(C4))) &&
1805 (C4->getValue() & ~C2->getValue()) == 0) {
1806 V2 = Builder->CreateOr(V1, ConstantExpr::getOr(C3, C4), "bitfield");
1807 return BinaryOperator::CreateAnd(V2,
1808 ConstantInt::get(B->getContext(),
1809 C1->getValue()|C2->getValue()));
1814 // Check to see if we have any common things being and'ed. If so, find the
1815 // terms for V1 & (V2|V3).
1816 if (Op0->hasOneUse() || Op1->hasOneUse()) {
1818 if (A == B) // (A & C)|(A & D) == A & (C|D)
1819 V1 = A, V2 = C, V3 = D;
1820 else if (A == D) // (A & C)|(B & A) == A & (B|C)
1821 V1 = A, V2 = B, V3 = C;
1822 else if (C == B) // (A & C)|(C & D) == C & (A|D)
1823 V1 = C, V2 = A, V3 = D;
1824 else if (C == D) // (A & C)|(B & C) == C & (A|B)
1825 V1 = C, V2 = A, V3 = B;
1828 Value *Or = Builder->CreateOr(V2, V3, "tmp");
1829 return BinaryOperator::CreateAnd(V1, Or);
1833 // (A & (C0?-1:0)) | (B & ~(C0?-1:0)) -> C0 ? A : B, and commuted variants.
1834 // Don't do this for vector select idioms, the code generator doesn't handle
1836 if (!I.getType()->isVectorTy()) {
1837 if (Instruction *Match = MatchSelectFromAndOr(A, B, C, D))
1839 if (Instruction *Match = MatchSelectFromAndOr(B, A, D, C))
1841 if (Instruction *Match = MatchSelectFromAndOr(C, B, A, D))
1843 if (Instruction *Match = MatchSelectFromAndOr(D, A, B, C))
1847 // ((A&~B)|(~A&B)) -> A^B
1848 if ((match(C, m_Not(m_Specific(D))) &&
1849 match(B, m_Not(m_Specific(A)))))
1850 return BinaryOperator::CreateXor(A, D);
1851 // ((~B&A)|(~A&B)) -> A^B
1852 if ((match(A, m_Not(m_Specific(D))) &&
1853 match(B, m_Not(m_Specific(C)))))
1854 return BinaryOperator::CreateXor(C, D);
1855 // ((A&~B)|(B&~A)) -> A^B
1856 if ((match(C, m_Not(m_Specific(B))) &&
1857 match(D, m_Not(m_Specific(A)))))
1858 return BinaryOperator::CreateXor(A, B);
1859 // ((~B&A)|(B&~A)) -> A^B
1860 if ((match(A, m_Not(m_Specific(B))) &&
1861 match(D, m_Not(m_Specific(C)))))
1862 return BinaryOperator::CreateXor(C, B);
1864 // ((A|B)&1)|(B&-2) -> (A&1) | B
1865 if (match(A, m_Or(m_Value(V1), m_Specific(B))) ||
1866 match(A, m_Or(m_Specific(B), m_Value(V1)))) {
1867 Instruction *Ret = FoldOrWithConstants(I, Op1, V1, B, C);
1868 if (Ret) return Ret;
1870 // (B&-2)|((A|B)&1) -> (A&1) | B
1871 if (match(B, m_Or(m_Specific(A), m_Value(V1))) ||
1872 match(B, m_Or(m_Value(V1), m_Specific(A)))) {
1873 Instruction *Ret = FoldOrWithConstants(I, Op0, A, V1, D);
1874 if (Ret) return Ret;
1878 // (X >> Z) | (Y >> Z) -> (X|Y) >> Z for all shifts.
1879 if (BinaryOperator *SI1 = dyn_cast<BinaryOperator>(Op1)) {
1880 if (BinaryOperator *SI0 = dyn_cast<BinaryOperator>(Op0))
1881 if (SI0->isShift() && SI0->getOpcode() == SI1->getOpcode() &&
1882 SI0->getOperand(1) == SI1->getOperand(1) &&
1883 (SI0->hasOneUse() || SI1->hasOneUse())) {
1884 Value *NewOp = Builder->CreateOr(SI0->getOperand(0), SI1->getOperand(0),
1886 return BinaryOperator::Create(SI1->getOpcode(), NewOp,
1887 SI1->getOperand(1));
1891 // (~A | ~B) == (~(A & B)) - De Morgan's Law
1892 if (Value *Op0NotVal = dyn_castNotVal(Op0))
1893 if (Value *Op1NotVal = dyn_castNotVal(Op1))
1894 if (Op0->hasOneUse() && Op1->hasOneUse()) {
1895 Value *And = Builder->CreateAnd(Op0NotVal, Op1NotVal,
1896 I.getName()+".demorgan");
1897 return BinaryOperator::CreateNot(And);
1900 if (ICmpInst *RHS = dyn_cast<ICmpInst>(I.getOperand(1)))
1901 if (ICmpInst *LHS = dyn_cast<ICmpInst>(I.getOperand(0)))
1902 if (Value *Res = FoldOrOfICmps(LHS, RHS))
1903 return ReplaceInstUsesWith(I, Res);
1905 // (fcmp uno x, c) | (fcmp uno y, c) -> (fcmp uno x, y)
1906 if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0)))
1907 if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
1908 if (Value *Res = FoldOrOfFCmps(LHS, RHS))
1909 return ReplaceInstUsesWith(I, Res);
1911 // fold (or (cast A), (cast B)) -> (cast (or A, B))
1912 if (CastInst *Op0C = dyn_cast<CastInst>(Op0)) {
1913 if (CastInst *Op1C = dyn_cast<CastInst>(Op1))
1914 if (Op0C->getOpcode() == Op1C->getOpcode()) {// same cast kind ?
1915 const Type *SrcTy = Op0C->getOperand(0)->getType();
1916 if (SrcTy == Op1C->getOperand(0)->getType() &&
1917 SrcTy->isIntOrIntVectorTy()) {
1918 Value *Op0COp = Op0C->getOperand(0), *Op1COp = Op1C->getOperand(0);
1920 if ((!isa<ICmpInst>(Op0COp) || !isa<ICmpInst>(Op1COp)) &&
1921 // Only do this if the casts both really cause code to be
1923 ShouldOptimizeCast(Op0C->getOpcode(), Op0COp, I.getType()) &&
1924 ShouldOptimizeCast(Op1C->getOpcode(), Op1COp, I.getType())) {
1925 Value *NewOp = Builder->CreateOr(Op0COp, Op1COp, I.getName());
1926 return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType());
1929 // If this is or(cast(icmp), cast(icmp)), try to fold this even if the
1930 // cast is otherwise not optimizable. This happens for vector sexts.
1931 if (ICmpInst *RHS = dyn_cast<ICmpInst>(Op1COp))
1932 if (ICmpInst *LHS = dyn_cast<ICmpInst>(Op0COp))
1933 if (Value *Res = FoldOrOfICmps(LHS, RHS))
1934 return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
1936 // If this is or(cast(fcmp), cast(fcmp)), try to fold this even if the
1937 // cast is otherwise not optimizable. This happens for vector sexts.
1938 if (FCmpInst *RHS = dyn_cast<FCmpInst>(Op1COp))
1939 if (FCmpInst *LHS = dyn_cast<FCmpInst>(Op0COp))
1940 if (Value *Res = FoldOrOfFCmps(LHS, RHS))
1941 return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
1946 return Changed ? &I : 0;
1949 Instruction *InstCombiner::visitXor(BinaryOperator &I) {
1950 bool Changed = SimplifyCommutative(I);
1951 Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
1953 if (isa<UndefValue>(Op1)) {
1954 if (isa<UndefValue>(Op0))
1955 // Handle undef ^ undef -> 0 special case. This is a common
1957 return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
1958 return ReplaceInstUsesWith(I, Op1); // X ^ undef -> undef
1963 return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
1965 // See if we can simplify any instructions used by the instruction whose sole
1966 // purpose is to compute bits we don't care about.
1967 if (SimplifyDemandedInstructionBits(I))
1969 if (I.getType()->isVectorTy())
1970 if (isa<ConstantAggregateZero>(Op1))
1971 return ReplaceInstUsesWith(I, Op0); // X ^ <0,0> -> X
1973 // Is this a ~ operation?
1974 if (Value *NotOp = dyn_castNotVal(&I)) {
1975 if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(NotOp)) {
1976 if (Op0I->getOpcode() == Instruction::And ||
1977 Op0I->getOpcode() == Instruction::Or) {
1978 // ~(~X & Y) --> (X | ~Y) - De Morgan's Law
1979 // ~(~X | Y) === (X & ~Y) - De Morgan's Law
1980 if (dyn_castNotVal(Op0I->getOperand(1)))
1981 Op0I->swapOperands();
1982 if (Value *Op0NotVal = dyn_castNotVal(Op0I->getOperand(0))) {
1984 Builder->CreateNot(Op0I->getOperand(1),
1985 Op0I->getOperand(1)->getName()+".not");
1986 if (Op0I->getOpcode() == Instruction::And)
1987 return BinaryOperator::CreateOr(Op0NotVal, NotY);
1988 return BinaryOperator::CreateAnd(Op0NotVal, NotY);
1991 // ~(X & Y) --> (~X | ~Y) - De Morgan's Law
1992 // ~(X | Y) === (~X & ~Y) - De Morgan's Law
1993 if (isFreeToInvert(Op0I->getOperand(0)) &&
1994 isFreeToInvert(Op0I->getOperand(1))) {
1996 Builder->CreateNot(Op0I->getOperand(0), "notlhs");
1998 Builder->CreateNot(Op0I->getOperand(1), "notrhs");
1999 if (Op0I->getOpcode() == Instruction::And)
2000 return BinaryOperator::CreateOr(NotX, NotY);
2001 return BinaryOperator::CreateAnd(NotX, NotY);
2004 } else if (Op0I->getOpcode() == Instruction::AShr) {
2005 // ~(~X >>s Y) --> (X >>s Y)
2006 if (Value *Op0NotVal = dyn_castNotVal(Op0I->getOperand(0)))
2007 return BinaryOperator::CreateAShr(Op0NotVal, Op0I->getOperand(1));
2013 if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) {
2014 if (RHS->isOne() && Op0->hasOneUse())
2015 // xor (cmp A, B), true = not (cmp A, B) = !cmp A, B
2016 if (CmpInst *CI = dyn_cast<CmpInst>(Op0))
2017 return CmpInst::Create(CI->getOpcode(),
2018 CI->getInversePredicate(),
2019 CI->getOperand(0), CI->getOperand(1));
2021 // fold (xor(zext(cmp)), 1) and (xor(sext(cmp)), -1) to ext(!cmp).
2022 if (CastInst *Op0C = dyn_cast<CastInst>(Op0)) {
2023 if (CmpInst *CI = dyn_cast<CmpInst>(Op0C->getOperand(0))) {
2024 if (CI->hasOneUse() && Op0C->hasOneUse()) {
2025 Instruction::CastOps Opcode = Op0C->getOpcode();
2026 if ((Opcode == Instruction::ZExt || Opcode == Instruction::SExt) &&
2027 (RHS == ConstantExpr::getCast(Opcode,
2028 ConstantInt::getTrue(I.getContext()),
2029 Op0C->getDestTy()))) {
2030 CI->setPredicate(CI->getInversePredicate());
2031 return CastInst::Create(Opcode, CI, Op0C->getType());
2037 if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0)) {
2038 // ~(c-X) == X-c-1 == X+(-c-1)
2039 if (Op0I->getOpcode() == Instruction::Sub && RHS->isAllOnesValue())
2040 if (Constant *Op0I0C = dyn_cast<Constant>(Op0I->getOperand(0))) {
2041 Constant *NegOp0I0C = ConstantExpr::getNeg(Op0I0C);
2042 Constant *ConstantRHS = ConstantExpr::getSub(NegOp0I0C,
2043 ConstantInt::get(I.getType(), 1));
2044 return BinaryOperator::CreateAdd(Op0I->getOperand(1), ConstantRHS);
2047 if (ConstantInt *Op0CI = dyn_cast<ConstantInt>(Op0I->getOperand(1))) {
2048 if (Op0I->getOpcode() == Instruction::Add) {
2049 // ~(X-c) --> (-c-1)-X
2050 if (RHS->isAllOnesValue()) {
2051 Constant *NegOp0CI = ConstantExpr::getNeg(Op0CI);
2052 return BinaryOperator::CreateSub(
2053 ConstantExpr::getSub(NegOp0CI,
2054 ConstantInt::get(I.getType(), 1)),
2055 Op0I->getOperand(0));
2056 } else if (RHS->getValue().isSignBit()) {
2057 // (X + C) ^ signbit -> (X + C + signbit)
2058 Constant *C = ConstantInt::get(I.getContext(),
2059 RHS->getValue() + Op0CI->getValue());
2060 return BinaryOperator::CreateAdd(Op0I->getOperand(0), C);
2063 } else if (Op0I->getOpcode() == Instruction::Or) {
2064 // (X|C1)^C2 -> X^(C1|C2) iff X&~C1 == 0
2065 if (MaskedValueIsZero(Op0I->getOperand(0), Op0CI->getValue())) {
2066 Constant *NewRHS = ConstantExpr::getOr(Op0CI, RHS);
2067 // Anything in both C1 and C2 is known to be zero, remove it from
2069 Constant *CommonBits = ConstantExpr::getAnd(Op0CI, RHS);
2070 NewRHS = ConstantExpr::getAnd(NewRHS,
2071 ConstantExpr::getNot(CommonBits));
2073 I.setOperand(0, Op0I->getOperand(0));
2074 I.setOperand(1, NewRHS);
2081 // Try to fold constant and into select arguments.
2082 if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
2083 if (Instruction *R = FoldOpIntoSelect(I, SI))
2085 if (isa<PHINode>(Op0))
2086 if (Instruction *NV = FoldOpIntoPhi(I))
2090 if (Value *X = dyn_castNotVal(Op0)) // ~A ^ A == -1
2092 return ReplaceInstUsesWith(I, Constant::getAllOnesValue(I.getType()));
2094 if (Value *X = dyn_castNotVal(Op1)) // A ^ ~A == -1
2096 return ReplaceInstUsesWith(I, Constant::getAllOnesValue(I.getType()));
2099 BinaryOperator *Op1I = dyn_cast<BinaryOperator>(Op1);
2102 if (match(Op1I, m_Or(m_Value(A), m_Value(B)))) {
2103 if (A == Op0) { // B^(B|A) == (A|B)^B
2104 Op1I->swapOperands();
2106 std::swap(Op0, Op1);
2107 } else if (B == Op0) { // B^(A|B) == (A|B)^B
2108 I.swapOperands(); // Simplified below.
2109 std::swap(Op0, Op1);
2111 } else if (match(Op1I, m_Xor(m_Specific(Op0), m_Value(B)))) {
2112 return ReplaceInstUsesWith(I, B); // A^(A^B) == B
2113 } else if (match(Op1I, m_Xor(m_Value(A), m_Specific(Op0)))) {
2114 return ReplaceInstUsesWith(I, A); // A^(B^A) == B
2115 } else if (match(Op1I, m_And(m_Value(A), m_Value(B))) &&
2117 if (A == Op0) { // A^(A&B) -> A^(B&A)
2118 Op1I->swapOperands();
2121 if (B == Op0) { // A^(B&A) -> (B&A)^A
2122 I.swapOperands(); // Simplified below.
2123 std::swap(Op0, Op1);
2128 BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0);
2131 if (match(Op0I, m_Or(m_Value(A), m_Value(B))) &&
2132 Op0I->hasOneUse()) {
2133 if (A == Op1) // (B|A)^B == (A|B)^B
2135 if (B == Op1) // (A|B)^B == A & ~B
2136 return BinaryOperator::CreateAnd(A, Builder->CreateNot(Op1, "tmp"));
2137 } else if (match(Op0I, m_Xor(m_Specific(Op1), m_Value(B)))) {
2138 return ReplaceInstUsesWith(I, B); // (A^B)^A == B
2139 } else if (match(Op0I, m_Xor(m_Value(A), m_Specific(Op1)))) {
2140 return ReplaceInstUsesWith(I, A); // (B^A)^A == B
2141 } else if (match(Op0I, m_And(m_Value(A), m_Value(B))) &&
2143 if (A == Op1) // (A&B)^A -> (B&A)^A
2145 if (B == Op1 && // (B&A)^A == ~B & A
2146 !isa<ConstantInt>(Op1)) { // Canonical form is (B&C)^C
2147 return BinaryOperator::CreateAnd(Builder->CreateNot(A, "tmp"), Op1);
2152 // (X >> Z) ^ (Y >> Z) -> (X^Y) >> Z for all shifts.
2153 if (Op0I && Op1I && Op0I->isShift() &&
2154 Op0I->getOpcode() == Op1I->getOpcode() &&
2155 Op0I->getOperand(1) == Op1I->getOperand(1) &&
2156 (Op1I->hasOneUse() || Op1I->hasOneUse())) {
2158 Builder->CreateXor(Op0I->getOperand(0), Op1I->getOperand(0),
2160 return BinaryOperator::Create(Op1I->getOpcode(), NewOp,
2161 Op1I->getOperand(1));
2165 Value *A, *B, *C, *D;
2166 // (A & B)^(A | B) -> A ^ B
2167 if (match(Op0I, m_And(m_Value(A), m_Value(B))) &&
2168 match(Op1I, m_Or(m_Value(C), m_Value(D)))) {
2169 if ((A == C && B == D) || (A == D && B == C))
2170 return BinaryOperator::CreateXor(A, B);
2172 // (A | B)^(A & B) -> A ^ B
2173 if (match(Op0I, m_Or(m_Value(A), m_Value(B))) &&
2174 match(Op1I, m_And(m_Value(C), m_Value(D)))) {
2175 if ((A == C && B == D) || (A == D && B == C))
2176 return BinaryOperator::CreateXor(A, B);
2180 if ((Op0I->hasOneUse() || Op1I->hasOneUse()) &&
2181 match(Op0I, m_And(m_Value(A), m_Value(B))) &&
2182 match(Op1I, m_And(m_Value(C), m_Value(D)))) {
2183 // (X & Y)^(X & Y) -> (Y^Z) & X
2184 Value *X = 0, *Y = 0, *Z = 0;
2186 X = A, Y = B, Z = D;
2188 X = A, Y = B, Z = C;
2190 X = B, Y = A, Z = D;
2192 X = B, Y = A, Z = C;
2195 Value *NewOp = Builder->CreateXor(Y, Z, Op0->getName());
2196 return BinaryOperator::CreateAnd(NewOp, X);
2201 // (icmp1 A, B) ^ (icmp2 A, B) --> (icmp3 A, B)
2202 if (ICmpInst *RHS = dyn_cast<ICmpInst>(I.getOperand(1)))
2203 if (ICmpInst *LHS = dyn_cast<ICmpInst>(I.getOperand(0)))
2204 if (PredicatesFoldable(LHS->getPredicate(), RHS->getPredicate())) {
2205 if (LHS->getOperand(0) == RHS->getOperand(1) &&
2206 LHS->getOperand(1) == RHS->getOperand(0))
2207 LHS->swapOperands();
2208 if (LHS->getOperand(0) == RHS->getOperand(0) &&
2209 LHS->getOperand(1) == RHS->getOperand(1)) {
2210 Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
2211 unsigned Code = getICmpCode(LHS) ^ getICmpCode(RHS);
2212 bool isSigned = LHS->isSigned() || RHS->isSigned();
2213 return ReplaceInstUsesWith(I,
2214 getICmpValue(isSigned, Code, Op0, Op1, Builder));
2218 // fold (xor (cast A), (cast B)) -> (cast (xor A, B))
2219 if (CastInst *Op0C = dyn_cast<CastInst>(Op0)) {
2220 if (CastInst *Op1C = dyn_cast<CastInst>(Op1))
2221 if (Op0C->getOpcode() == Op1C->getOpcode()) { // same cast kind?
2222 const Type *SrcTy = Op0C->getOperand(0)->getType();
2223 if (SrcTy == Op1C->getOperand(0)->getType() && SrcTy->isIntegerTy() &&
2224 // Only do this if the casts both really cause code to be generated.
2225 ShouldOptimizeCast(Op0C->getOpcode(), Op0C->getOperand(0),
2227 ShouldOptimizeCast(Op1C->getOpcode(), Op1C->getOperand(0),
2229 Value *NewOp = Builder->CreateXor(Op0C->getOperand(0),
2230 Op1C->getOperand(0), I.getName());
2231 return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType());
2236 return Changed ? &I : 0;