X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTransforms%2FInstCombine%2FInstCombineAndOrXor.cpp;h=4f5d65ab785f9bbc7387bfc8c8a7f08b42171872;hb=86118b4532f0790fe7168fcf00e61a09fa2e5362;hp=e19ddd1983a57f248a8d16ecbefc6a043f8cf9bf;hpb=40bf5e7a6811bf31b6853d2c71c08feed871419b;p=oota-llvm.git diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index e19ddd1983a..4f5d65ab785 100644 --- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -12,21 +12,15 @@ //===----------------------------------------------------------------------===// #include "InstCombine.h" -#include "llvm/Intrinsics.h" #include "llvm/Analysis/InstructionSimplify.h" -#include "llvm/Support/PatternMatch.h" +#include "llvm/IR/ConstantRange.h" +#include "llvm/IR/Intrinsics.h" +#include "llvm/IR/PatternMatch.h" +#include "llvm/Transforms/Utils/CmpInstAnalysis.h" using namespace llvm; using namespace PatternMatch; - -/// AddOne - Add one to a ConstantInt. -static Constant *AddOne(Constant *C) { - return ConstantExpr::getAdd(C, ConstantInt::get(C->getType(), 1)); -} -/// SubOne - Subtract one from a ConstantInt. -static Constant *SubOne(ConstantInt *C) { - return ConstantInt::get(C->getContext(), C->getValue()-1); -} +#define DEBUG_TYPE "instcombine" /// isFreeToInvert - Return true if the specified value is free to invert (apply /// ~ to). This happens in cases where the ~ can be eliminated. @@ -34,15 +28,15 @@ static inline bool isFreeToInvert(Value *V) { // ~(~(X)) -> X. if (BinaryOperator::isNot(V)) return true; - + // Constants can be considered to be not'ed values. if (isa(V)) return true; - + // Compares can be inverted if they have a single use. if (CmpInst *CI = dyn_cast(V)) return CI->hasOneUse(); - + return false; } @@ -54,55 +48,11 @@ static inline Value *dyn_castNotVal(Value *V) { if (!isFreeToInvert(Operand)) return Operand; } - + // Constants can be considered to be not'ed values... if (ConstantInt *C = dyn_cast(V)) return ConstantInt::get(C->getType(), ~C->getValue()); - return 0; -} - - -/// getICmpCode - Encode a icmp predicate into a three bit mask. These bits -/// are carefully arranged to allow folding of expressions such as: -/// -/// (A < B) | (A > B) --> (A != B) -/// -/// Note that this is only valid if the first and second predicates have the -/// same sign. Is illegal to do: (A u< B) | (A s> B) -/// -/// Three bits are used to represent the condition, as follows: -/// 0 A > B -/// 1 A == B -/// 2 A < B -/// -/// <=> Value Definition -/// 000 0 Always false -/// 001 1 A > B -/// 010 2 A == B -/// 011 3 A >= B -/// 100 4 A < B -/// 101 5 A != B -/// 110 6 A <= B -/// 111 7 Always true -/// -static unsigned getICmpCode(const ICmpInst *ICI) { - switch (ICI->getPredicate()) { - // False -> 0 - case ICmpInst::ICMP_UGT: return 1; // 001 - case ICmpInst::ICMP_SGT: return 1; // 001 - case ICmpInst::ICMP_EQ: return 2; // 010 - case ICmpInst::ICMP_UGE: return 3; // 011 - case ICmpInst::ICMP_SGE: return 3; // 011 - case ICmpInst::ICMP_ULT: return 4; // 100 - case ICmpInst::ICMP_SLT: return 4; // 100 - case ICmpInst::ICMP_NE: return 5; // 101 - case ICmpInst::ICMP_ULE: return 6; // 110 - case ICmpInst::ICMP_SLE: return 6; // 110 - // True -> 7 - default: - llvm_unreachable("Invalid ICmp predicate!"); - return 0; - } + return nullptr; } /// getFCmpCode - Similar to getICmpCode but for FCmpInst. This encodes a fcmp @@ -129,31 +79,19 @@ static unsigned getFCmpCode(FCmpInst::Predicate CC, bool &isOrdered) { default: // Not expecting FCMP_FALSE and FCMP_TRUE; llvm_unreachable("Unexpected FCmp predicate!"); - return 0; } } -/// getICmpValue - This is the complement of getICmpCode, which turns an -/// opcode and two operands into either a constant true or false, or a brand +/// getNewICmpValue - This is the complement of getICmpCode, which turns an +/// opcode and two operands into either a constant true or false, or a brand /// new ICmp instruction. The sign is passed in to determine which kind /// of predicate to use in the new icmp instruction. -static Value *getICmpValue(bool Sign, unsigned Code, Value *LHS, Value *RHS, - InstCombiner::BuilderTy *Builder) { - CmpInst::Predicate Pred; - switch (Code) { - default: assert(0 && "Illegal ICmp code!"); - case 0: // False. - return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0); - case 1: Pred = Sign ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT; break; - case 2: Pred = ICmpInst::ICMP_EQ; break; - case 3: Pred = Sign ? ICmpInst::ICMP_SGE : ICmpInst::ICMP_UGE; break; - case 4: Pred = Sign ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT; break; - case 5: Pred = ICmpInst::ICMP_NE; break; - case 6: Pred = Sign ? ICmpInst::ICMP_SLE : ICmpInst::ICMP_ULE; break; - case 7: // True. - return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 1); - } - return Builder->CreateICmp(Pred, LHS, RHS); +static Value *getNewICmpValue(bool Sign, unsigned Code, Value *LHS, Value *RHS, + InstCombiner::BuilderTy *Builder) { + ICmpInst::Predicate NewPred; + if (Value *NewConstant = getICmpValue(Sign, Code, LHS, RHS, NewPred)) + return NewConstant; + return Builder->CreateICmp(NewPred, LHS, RHS); } /// getFCmpValue - This is the complement of getFCmpCode, which turns an @@ -164,7 +102,7 @@ static Value *getFCmpValue(bool isordered, unsigned code, InstCombiner::BuilderTy *Builder) { CmpInst::Predicate Pred; switch (code) { - default: assert(0 && "Illegal FCmp code!"); + default: llvm_unreachable("Illegal FCmp code!"); case 0: Pred = isordered ? FCmpInst::FCMP_ORD : FCmpInst::FCMP_UNO; break; case 1: Pred = isordered ? FCmpInst::FCMP_OGT : FCmpInst::FCMP_UGT; break; case 2: Pred = isordered ? FCmpInst::FCMP_OEQ : FCmpInst::FCMP_UEQ; break; @@ -172,19 +110,13 @@ static Value *getFCmpValue(bool isordered, unsigned code, case 4: Pred = isordered ? FCmpInst::FCMP_OLT : FCmpInst::FCMP_ULT; break; case 5: Pred = isordered ? FCmpInst::FCMP_ONE : FCmpInst::FCMP_UNE; break; case 6: Pred = isordered ? FCmpInst::FCMP_OLE : FCmpInst::FCMP_ULE; break; - case 7: return ConstantInt::getTrue(LHS->getContext()); + case 7: + if (!isordered) return ConstantInt::getTrue(LHS->getContext()); + Pred = FCmpInst::FCMP_ORD; break; } return Builder->CreateFCmp(Pred, LHS, RHS); } -/// PredicatesFoldable - Return true if both predicates match sign or if at -/// least one of them is an equality comparison (which is signless). -static bool PredicatesFoldable(ICmpInst::Predicate p1, ICmpInst::Predicate p2) { - return (CmpInst::isSigned(p1) == CmpInst::isSigned(p2)) || - (CmpInst::isSigned(p1) && ICmpInst::isEquality(p2)) || - (CmpInst::isSigned(p2) && ICmpInst::isEquality(p1)); -} - // OptAndOp - This handles expressions of the form ((val OP C1) & C2). Where // the Op parameter is 'OP', OpRHS is 'C1', and AndRHS is 'C2'. Op is // guaranteed to be a binary operator. @@ -193,7 +125,7 @@ Instruction *InstCombiner::OptAndOp(Instruction *Op, ConstantInt *AndRHS, BinaryOperator &TheAnd) { Value *X = Op->getOperand(0); - Constant *Together = 0; + Constant *Together = nullptr; if (!Op->isShift()) Together = ConstantExpr::getAnd(AndRHS, OpRHS); @@ -207,29 +139,40 @@ Instruction *InstCombiner::OptAndOp(Instruction *Op, } break; case Instruction::Or: - if (Together == AndRHS) // (X | C) & C --> C - return ReplaceInstUsesWith(TheAnd, AndRHS); + if (Op->hasOneUse()){ + if (Together != OpRHS) { + // (X | C1) & C2 --> (X | (C1&C2)) & C2 + Value *Or = Builder->CreateOr(X, Together); + Or->takeName(Op); + return BinaryOperator::CreateAnd(Or, AndRHS); + } - if (Op->hasOneUse() && Together != OpRHS) { - // (X | C1) & C2 --> (X | (C1&C2)) & C2 - Value *Or = Builder->CreateOr(X, Together); - Or->takeName(Op); - return BinaryOperator::CreateAnd(Or, AndRHS); + ConstantInt *TogetherCI = dyn_cast(Together); + if (TogetherCI && !TogetherCI->isZero()){ + // (X | C1) & C2 --> (X & (C2^(C1&C2))) | C1 + // NOTE: This reduces the number of bits set in the & mask, which + // can expose opportunities for store narrowing. + Together = ConstantExpr::getXor(AndRHS, Together); + Value *And = Builder->CreateAnd(X, Together); + And->takeName(Op); + return BinaryOperator::CreateOr(And, OpRHS); + } } + break; case Instruction::Add: if (Op->hasOneUse()) { // Adding a one to a single bit bit-field should be turned into an XOR // of the bit. First thing to check is to see if this AND is with a // single bit constant. - const APInt &AndRHSV = cast(AndRHS)->getValue(); + const APInt &AndRHSV = AndRHS->getValue(); // If there is only one bit set. if (AndRHSV.isPowerOf2()) { // Ok, at this point, we know that we are masking the result of the // ADD down to exactly one bit. If the constant we are adding has // no bits set below this bit, then we can eliminate the ADD. - const APInt& AddRHS = cast(OpRHS)->getValue(); + const APInt& AddRHS = OpRHS->getValue(); // Check to see if any bits below the one bit set in AndRHSV are set. if ((AddRHS & (AndRHSV-1)) == 0) { @@ -258,13 +201,13 @@ Instruction *InstCombiner::OptAndOp(Instruction *Op, uint32_t BitWidth = AndRHS->getType()->getBitWidth(); uint32_t OpRHSVal = OpRHS->getLimitedValue(BitWidth); APInt ShlMask(APInt::getHighBitsSet(BitWidth, BitWidth-OpRHSVal)); - ConstantInt *CI = ConstantInt::get(AndRHS->getContext(), - AndRHS->getValue() & ShlMask); + ConstantInt *CI = Builder->getInt(AndRHS->getValue() & ShlMask); - if (CI->getValue() == ShlMask) { - // Masking out bits that the shift already masks + if (CI->getValue() == ShlMask) + // Masking out bits that the shift already masks. return ReplaceInstUsesWith(TheAnd, Op); // No need for the and. - } else if (CI != AndRHS) { // Reducing bits set in and. + + if (CI != AndRHS) { // Reducing bits set in and. TheAnd.setOperand(1, CI); return &TheAnd; } @@ -278,13 +221,13 @@ Instruction *InstCombiner::OptAndOp(Instruction *Op, uint32_t BitWidth = AndRHS->getType()->getBitWidth(); uint32_t OpRHSVal = OpRHS->getLimitedValue(BitWidth); APInt ShrMask(APInt::getLowBitsSet(BitWidth, BitWidth - OpRHSVal)); - ConstantInt *CI = ConstantInt::get(Op->getContext(), - AndRHS->getValue() & ShrMask); + ConstantInt *CI = Builder->getInt(AndRHS->getValue() & ShrMask); - if (CI->getValue() == ShrMask) { - // Masking out bits that the shift already masks. + if (CI->getValue() == ShrMask) + // Masking out bits that the shift already masks. return ReplaceInstUsesWith(TheAnd, Op); - } else if (CI != AndRHS) { + + if (CI != AndRHS) { TheAnd.setOperand(1, CI); // Reduce bits set in and cst. return &TheAnd; } @@ -298,8 +241,7 @@ Instruction *InstCombiner::OptAndOp(Instruction *Op, uint32_t BitWidth = AndRHS->getType()->getBitWidth(); uint32_t OpRHSVal = OpRHS->getLimitedValue(BitWidth); APInt ShrMask(APInt::getLowBitsSet(BitWidth, BitWidth - OpRHSVal)); - Constant *C = ConstantInt::get(Op->getContext(), - AndRHS->getValue() & ShrMask); + Constant *C = Builder->getInt(AndRHS->getValue() & ShrMask); if (C == AndRHS) { // Masking out bits shifted in. // (Val ashr C1) & C2 -> (Val lshr C1) & C2 // Make the argument unsigned. @@ -310,28 +252,27 @@ Instruction *InstCombiner::OptAndOp(Instruction *Op, } break; } - return 0; + return nullptr; } - -/// InsertRangeTest - Emit a computation of: (V >= Lo && V < Hi) if Inside is -/// true, otherwise (V < Lo || V >= Hi). In pratice, we emit the more efficient -/// (V-Lo) = Lo && V < Hi) if Inside is true, otherwise +/// (V < Lo || V >= Hi). In practice, we emit the more efficient +/// (V-Lo) \(ConstantExpr::getICmp((isSigned ? + assert(cast(ConstantExpr::getICmp((isSigned ? ICmpInst::ICMP_SLE:ICmpInst::ICMP_ULE), Lo, Hi))->getZExtValue() && "Lo is not <= Hi in range emission code!"); - + if (Inside) { if (Lo == Hi) // Trivially false. - return ConstantInt::getFalse(V->getContext()); + return Builder->getFalse(); // V >= Min && V < Hi --> V < Hi if (cast(Lo)->isMinValue(isSigned)) { - ICmpInst::Predicate pred = (isSigned ? + ICmpInst::Predicate pred = (isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT); return Builder->CreateICmp(pred, V, Hi); } @@ -344,12 +285,12 @@ Value *InstCombiner::InsertRangeTest(Value *V, Constant *Lo, Constant *Hi, } if (Lo == Hi) // Trivially true. - return ConstantInt::getTrue(V->getContext()); + return Builder->getTrue(); // V < Min || V >= Hi -> V > Hi-1 Hi = SubOne(cast(Hi)); if (cast(Lo)->isMinValue(isSigned)) { - ICmpInst::Predicate pred = (isSigned ? + ICmpInst::Predicate pred = (isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT); return Builder->CreateICmp(pred, V, Hi); } @@ -374,14 +315,14 @@ static bool isRunOfOnes(ConstantInt *Val, uint32_t &MB, uint32_t &ME) { // look for the first zero bit after the run of ones MB = BitWidth - ((V - 1) ^ V).countLeadingZeros(); // look for the first non-zero bit - ME = V.getActiveBits(); + ME = V.getActiveBits(); return true; } /// FoldLogicalPlusAnd - This is part of an expression (LHS +/- RHS) & Mask, /// where isSub determines whether the operator is a sub. If we can fold one of /// the following xforms: -/// +/// /// ((A & N) +/- B) & Mask -> (A +/- B) & Mask iff N&Mask == Mask /// ((A | N) +/- B) & Mask -> (A +/- B) & Mask iff N&Mask == 0 /// ((A ^ N) +/- B) & Mask -> (A +/- B) & Mask iff N&Mask == 0 @@ -393,17 +334,17 @@ Value *InstCombiner::FoldLogicalPlusAnd(Value *LHS, Value *RHS, Instruction &I) { Instruction *LHSI = dyn_cast(LHS); if (!LHSI || LHSI->getNumOperands() != 2 || - !isa(LHSI->getOperand(1))) return 0; + !isa(LHSI->getOperand(1))) return nullptr; ConstantInt *N = cast(LHSI->getOperand(1)); switch (LHSI->getOpcode()) { - default: return 0; + default: return nullptr; case Instruction::And: if (ConstantExpr::getAnd(N, Mask) == Mask) { // If the AndRHS is a power of two minus one (0+1+), this is simple. - if ((Mask->getValue().countLeadingZeros() + - Mask->getValue().countPopulation()) == + if ((Mask->getValue().countLeadingZeros() + + Mask->getValue().countPopulation()) == Mask->getValue().getBitWidth()) break; @@ -418,22 +359,434 @@ Value *InstCombiner::FoldLogicalPlusAnd(Value *LHS, Value *RHS, break; } } - return 0; + return nullptr; case Instruction::Or: case Instruction::Xor: // If the AndRHS is a power of two minus one (0+1+), and N&Mask == 0 - if ((Mask->getValue().countLeadingZeros() + + if ((Mask->getValue().countLeadingZeros() + Mask->getValue().countPopulation()) == Mask->getValue().getBitWidth() && ConstantExpr::getAnd(N, Mask)->isNullValue()) break; - return 0; + return nullptr; } - + if (isSub) return Builder->CreateSub(LHSI->getOperand(0), RHS, "fold"); return Builder->CreateAdd(LHSI->getOperand(0), RHS, "fold"); } +/// enum for classifying (icmp eq (A & B), C) and (icmp ne (A & B), C) +/// One of A and B is considered the mask, the other the value. This is +/// described as the "AMask" or "BMask" part of the enum. If the enum +/// contains only "Mask", then both A and B can be considered masks. +/// If A is the mask, then it was proven, that (A & C) == C. This +/// is trivial if C == A, or C == 0. If both A and C are constants, this +/// proof is also easy. +/// For the following explanations we assume that A is the mask. +/// The part "AllOnes" declares, that the comparison is true only +/// if (A & B) == A, or all bits of A are set in B. +/// Example: (icmp eq (A & 3), 3) -> FoldMskICmp_AMask_AllOnes +/// The part "AllZeroes" declares, that the comparison is true only +/// if (A & B) == 0, or all bits of A are cleared in B. +/// Example: (icmp eq (A & 3), 0) -> FoldMskICmp_Mask_AllZeroes +/// The part "Mixed" declares, that (A & B) == C and C might or might not +/// contain any number of one bits and zero bits. +/// Example: (icmp eq (A & 3), 1) -> FoldMskICmp_AMask_Mixed +/// The Part "Not" means, that in above descriptions "==" should be replaced +/// by "!=". +/// Example: (icmp ne (A & 3), 3) -> FoldMskICmp_AMask_NotAllOnes +/// If the mask A contains a single bit, then the following is equivalent: +/// (icmp eq (A & B), A) equals (icmp ne (A & B), 0) +/// (icmp ne (A & B), A) equals (icmp eq (A & B), 0) +enum MaskedICmpType { + FoldMskICmp_AMask_AllOnes = 1, + FoldMskICmp_AMask_NotAllOnes = 2, + FoldMskICmp_BMask_AllOnes = 4, + FoldMskICmp_BMask_NotAllOnes = 8, + FoldMskICmp_Mask_AllZeroes = 16, + FoldMskICmp_Mask_NotAllZeroes = 32, + FoldMskICmp_AMask_Mixed = 64, + FoldMskICmp_AMask_NotMixed = 128, + FoldMskICmp_BMask_Mixed = 256, + FoldMskICmp_BMask_NotMixed = 512 +}; + +/// return the set of pattern classes (from MaskedICmpType) +/// that (icmp SCC (A & B), C) satisfies +static unsigned getTypeOfMaskedICmp(Value* A, Value* B, Value* C, + ICmpInst::Predicate SCC) +{ + ConstantInt *ACst = dyn_cast(A); + ConstantInt *BCst = dyn_cast(B); + ConstantInt *CCst = dyn_cast(C); + bool icmp_eq = (SCC == ICmpInst::ICMP_EQ); + bool icmp_abit = (ACst && !ACst->isZero() && + ACst->getValue().isPowerOf2()); + bool icmp_bbit = (BCst && !BCst->isZero() && + BCst->getValue().isPowerOf2()); + unsigned result = 0; + if (CCst && CCst->isZero()) { + // if C is zero, then both A and B qualify as mask + result |= (icmp_eq ? (FoldMskICmp_Mask_AllZeroes | + FoldMskICmp_Mask_AllZeroes | + FoldMskICmp_AMask_Mixed | + FoldMskICmp_BMask_Mixed) + : (FoldMskICmp_Mask_NotAllZeroes | + FoldMskICmp_Mask_NotAllZeroes | + FoldMskICmp_AMask_NotMixed | + FoldMskICmp_BMask_NotMixed)); + if (icmp_abit) + result |= (icmp_eq ? (FoldMskICmp_AMask_NotAllOnes | + FoldMskICmp_AMask_NotMixed) + : (FoldMskICmp_AMask_AllOnes | + FoldMskICmp_AMask_Mixed)); + if (icmp_bbit) + result |= (icmp_eq ? (FoldMskICmp_BMask_NotAllOnes | + FoldMskICmp_BMask_NotMixed) + : (FoldMskICmp_BMask_AllOnes | + FoldMskICmp_BMask_Mixed)); + return result; + } + if (A == C) { + result |= (icmp_eq ? (FoldMskICmp_AMask_AllOnes | + FoldMskICmp_AMask_Mixed) + : (FoldMskICmp_AMask_NotAllOnes | + FoldMskICmp_AMask_NotMixed)); + if (icmp_abit) + result |= (icmp_eq ? (FoldMskICmp_Mask_NotAllZeroes | + FoldMskICmp_AMask_NotMixed) + : (FoldMskICmp_Mask_AllZeroes | + FoldMskICmp_AMask_Mixed)); + } else if (ACst && CCst && + ConstantExpr::getAnd(ACst, CCst) == CCst) { + result |= (icmp_eq ? FoldMskICmp_AMask_Mixed + : FoldMskICmp_AMask_NotMixed); + } + if (B == C) { + result |= (icmp_eq ? (FoldMskICmp_BMask_AllOnes | + FoldMskICmp_BMask_Mixed) + : (FoldMskICmp_BMask_NotAllOnes | + FoldMskICmp_BMask_NotMixed)); + if (icmp_bbit) + result |= (icmp_eq ? (FoldMskICmp_Mask_NotAllZeroes | + FoldMskICmp_BMask_NotMixed) + : (FoldMskICmp_Mask_AllZeroes | + FoldMskICmp_BMask_Mixed)); + } else if (BCst && CCst && + ConstantExpr::getAnd(BCst, CCst) == CCst) { + result |= (icmp_eq ? FoldMskICmp_BMask_Mixed + : FoldMskICmp_BMask_NotMixed); + } + return result; +} + +/// Convert an analysis of a masked ICmp into its equivalent if all boolean +/// operations had the opposite sense. Since each "NotXXX" flag (recording !=) +/// is adjacent to the corresponding normal flag (recording ==), this just +/// involves swapping those bits over. +static unsigned conjugateICmpMask(unsigned Mask) { + unsigned NewMask; + NewMask = (Mask & (FoldMskICmp_AMask_AllOnes | FoldMskICmp_BMask_AllOnes | + FoldMskICmp_Mask_AllZeroes | FoldMskICmp_AMask_Mixed | + FoldMskICmp_BMask_Mixed)) + << 1; + + NewMask |= + (Mask & (FoldMskICmp_AMask_NotAllOnes | FoldMskICmp_BMask_NotAllOnes | + FoldMskICmp_Mask_NotAllZeroes | FoldMskICmp_AMask_NotMixed | + FoldMskICmp_BMask_NotMixed)) + >> 1; + + return NewMask; +} + +/// decomposeBitTestICmp - Decompose an icmp into the form ((X & Y) pred Z) +/// if possible. The returned predicate is either == or !=. Returns false if +/// decomposition fails. +static bool decomposeBitTestICmp(const ICmpInst *I, ICmpInst::Predicate &Pred, + Value *&X, Value *&Y, Value *&Z) { + ConstantInt *C = dyn_cast(I->getOperand(1)); + if (!C) + return false; + + switch (I->getPredicate()) { + default: + return false; + case ICmpInst::ICMP_SLT: + // X < 0 is equivalent to (X & SignBit) != 0. + if (!C->isZero()) + return false; + Y = ConstantInt::get(I->getContext(), APInt::getSignBit(C->getBitWidth())); + Pred = ICmpInst::ICMP_NE; + break; + case ICmpInst::ICMP_SGT: + // X > -1 is equivalent to (X & SignBit) == 0. + if (!C->isAllOnesValue()) + return false; + Y = ConstantInt::get(I->getContext(), APInt::getSignBit(C->getBitWidth())); + Pred = ICmpInst::ICMP_EQ; + break; + case ICmpInst::ICMP_ULT: + // X getValue().isPowerOf2()) + return false; + Y = ConstantInt::get(I->getContext(), -C->getValue()); + Pred = ICmpInst::ICMP_EQ; + break; + case ICmpInst::ICMP_UGT: + // X >u 2^n-1 is equivalent to (X & ~(2^n-1)) != 0. + if (!(C->getValue() + 1).isPowerOf2()) + return false; + Y = ConstantInt::get(I->getContext(), ~C->getValue()); + Pred = ICmpInst::ICMP_NE; + break; + } + + X = I->getOperand(0); + Z = ConstantInt::getNullValue(C->getType()); + return true; +} + +/// foldLogOpOfMaskedICmpsHelper: +/// handle (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E) +/// return the set of pattern classes (from MaskedICmpType) +/// that both LHS and RHS satisfy +static unsigned foldLogOpOfMaskedICmpsHelper(Value*& A, + Value*& B, Value*& C, + Value*& D, Value*& E, + ICmpInst *LHS, ICmpInst *RHS, + ICmpInst::Predicate &LHSCC, + ICmpInst::Predicate &RHSCC) { + if (LHS->getOperand(0)->getType() != RHS->getOperand(0)->getType()) return 0; + // vectors are not (yet?) supported + if (LHS->getOperand(0)->getType()->isVectorTy()) return 0; + + // Here comes the tricky part: + // LHS might be of the form L11 & L12 == X, X == L21 & L22, + // and L11 & L12 == L21 & L22. The same goes for RHS. + // Now we must find those components L** and R**, that are equal, so + // that we can extract the parameters A, B, C, D, and E for the canonical + // above. + Value *L1 = LHS->getOperand(0); + Value *L2 = LHS->getOperand(1); + Value *L11,*L12,*L21,*L22; + // Check whether the icmp can be decomposed into a bit test. + if (decomposeBitTestICmp(LHS, LHSCC, L11, L12, L2)) { + L21 = L22 = L1 = nullptr; + } else { + // Look for ANDs in the LHS icmp. + if (!L1->getType()->isIntegerTy()) { + // You can icmp pointers, for example. They really aren't masks. + L11 = L12 = nullptr; + } else if (!match(L1, m_And(m_Value(L11), m_Value(L12)))) { + // Any icmp can be viewed as being trivially masked; if it allows us to + // remove one, it's worth it. + L11 = L1; + L12 = Constant::getAllOnesValue(L1->getType()); + } + + if (!L2->getType()->isIntegerTy()) { + // You can icmp pointers, for example. They really aren't masks. + L21 = L22 = nullptr; + } else if (!match(L2, m_And(m_Value(L21), m_Value(L22)))) { + L21 = L2; + L22 = Constant::getAllOnesValue(L2->getType()); + } + } + + // Bail if LHS was a icmp that can't be decomposed into an equality. + if (!ICmpInst::isEquality(LHSCC)) + return 0; + + Value *R1 = RHS->getOperand(0); + Value *R2 = RHS->getOperand(1); + Value *R11,*R12; + bool ok = false; + if (decomposeBitTestICmp(RHS, RHSCC, R11, R12, R2)) { + if (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22) { + A = R11; D = R12; + } else if (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22) { + A = R12; D = R11; + } else { + return 0; + } + E = R2; R1 = nullptr; ok = true; + } else if (R1->getType()->isIntegerTy()) { + if (!match(R1, m_And(m_Value(R11), m_Value(R12)))) { + // As before, model no mask as a trivial mask if it'll let us do an + // optimisation. + R11 = R1; + R12 = Constant::getAllOnesValue(R1->getType()); + } + + if (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22) { + A = R11; D = R12; E = R2; ok = true; + } else if (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22) { + A = R12; D = R11; E = R2; ok = true; + } + } + + // Bail if RHS was a icmp that can't be decomposed into an equality. + if (!ICmpInst::isEquality(RHSCC)) + return 0; + + // Look for ANDs in on the right side of the RHS icmp. + if (!ok && R2->getType()->isIntegerTy()) { + if (!match(R2, m_And(m_Value(R11), m_Value(R12)))) { + R11 = R2; + R12 = Constant::getAllOnesValue(R2->getType()); + } + + if (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22) { + A = R11; D = R12; E = R1; ok = true; + } else if (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22) { + A = R12; D = R11; E = R1; ok = true; + } else { + return 0; + } + } + if (!ok) + return 0; + + if (L11 == A) { + B = L12; C = L2; + } else if (L12 == A) { + B = L11; C = L2; + } else if (L21 == A) { + B = L22; C = L1; + } else if (L22 == A) { + B = L21; C = L1; + } + + unsigned left_type = getTypeOfMaskedICmp(A, B, C, LHSCC); + unsigned right_type = getTypeOfMaskedICmp(A, D, E, RHSCC); + return left_type & right_type; +} +/// foldLogOpOfMaskedICmps: +/// try to fold (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E) +/// into a single (icmp(A & X) ==/!= Y) +static Value* foldLogOpOfMaskedICmps(ICmpInst *LHS, ICmpInst *RHS, bool IsAnd, + llvm::InstCombiner::BuilderTy* Builder) { + Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr, *E = nullptr; + ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate(); + unsigned mask = foldLogOpOfMaskedICmpsHelper(A, B, C, D, E, LHS, RHS, + LHSCC, RHSCC); + if (mask == 0) return nullptr; + assert(ICmpInst::isEquality(LHSCC) && ICmpInst::isEquality(RHSCC) && + "foldLogOpOfMaskedICmpsHelper must return an equality predicate."); + + // In full generality: + // (icmp (A & B) Op C) | (icmp (A & D) Op E) + // == ![ (icmp (A & B) !Op C) & (icmp (A & D) !Op E) ] + // + // If the latter can be converted into (icmp (A & X) Op Y) then the former is + // equivalent to (icmp (A & X) !Op Y). + // + // Therefore, we can pretend for the rest of this function that we're dealing + // with the conjunction, provided we flip the sense of any comparisons (both + // input and output). + + // In most cases we're going to produce an EQ for the "&&" case. + ICmpInst::Predicate NEWCC = IsAnd ? ICmpInst::ICMP_EQ : ICmpInst::ICMP_NE; + if (!IsAnd) { + // Convert the masking analysis into its equivalent with negated + // comparisons. + mask = conjugateICmpMask(mask); + } + + if (mask & FoldMskICmp_Mask_AllZeroes) { + // (icmp eq (A & B), 0) & (icmp eq (A & D), 0) + // -> (icmp eq (A & (B|D)), 0) + Value* newOr = Builder->CreateOr(B, D); + Value* newAnd = Builder->CreateAnd(A, newOr); + // we can't use C as zero, because we might actually handle + // (icmp ne (A & B), B) & (icmp ne (A & D), D) + // with B and D, having a single bit set + Value* zero = Constant::getNullValue(A->getType()); + return Builder->CreateICmp(NEWCC, newAnd, zero); + } + if (mask & FoldMskICmp_BMask_AllOnes) { + // (icmp eq (A & B), B) & (icmp eq (A & D), D) + // -> (icmp eq (A & (B|D)), (B|D)) + Value* newOr = Builder->CreateOr(B, D); + Value* newAnd = Builder->CreateAnd(A, newOr); + return Builder->CreateICmp(NEWCC, newAnd, newOr); + } + if (mask & FoldMskICmp_AMask_AllOnes) { + // (icmp eq (A & B), A) & (icmp eq (A & D), A) + // -> (icmp eq (A & (B&D)), A) + Value* newAnd1 = Builder->CreateAnd(B, D); + Value* newAnd = Builder->CreateAnd(A, newAnd1); + return Builder->CreateICmp(NEWCC, newAnd, A); + } + + // Remaining cases assume at least that B and D are constant, and depend on + // their actual values. This isn't strictly, necessary, just a "handle the + // easy cases for now" decision. + ConstantInt *BCst = dyn_cast(B); + if (!BCst) return nullptr; + ConstantInt *DCst = dyn_cast(D); + if (!DCst) return nullptr; + + if (mask & (FoldMskICmp_Mask_NotAllZeroes | FoldMskICmp_BMask_NotAllOnes)) { + // (icmp ne (A & B), 0) & (icmp ne (A & D), 0) and + // (icmp ne (A & B), B) & (icmp ne (A & D), D) + // -> (icmp ne (A & B), 0) or (icmp ne (A & D), 0) + // Only valid if one of the masks is a superset of the other (check "B&D" is + // the same as either B or D). + APInt NewMask = BCst->getValue() & DCst->getValue(); + + if (NewMask == BCst->getValue()) + return LHS; + else if (NewMask == DCst->getValue()) + return RHS; + } + if (mask & FoldMskICmp_AMask_NotAllOnes) { + // (icmp ne (A & B), B) & (icmp ne (A & D), D) + // -> (icmp ne (A & B), A) or (icmp ne (A & D), A) + // Only valid if one of the masks is a superset of the other (check "B|D" is + // the same as either B or D). + APInt NewMask = BCst->getValue() | DCst->getValue(); + + if (NewMask == BCst->getValue()) + return LHS; + else if (NewMask == DCst->getValue()) + return RHS; + } + if (mask & FoldMskICmp_BMask_Mixed) { + // (icmp eq (A & B), C) & (icmp eq (A & D), E) + // We already know that B & C == C && D & E == E. + // If we can prove that (B & D) & (C ^ E) == 0, that is, the bits of + // C and E, which are shared by both the mask B and the mask D, don't + // contradict, then we can transform to + // -> (icmp eq (A & (B|D)), (C|E)) + // Currently, we only handle the case of B, C, D, and E being constant. + // we can't simply use C and E, because we might actually handle + // (icmp ne (A & B), B) & (icmp eq (A & D), D) + // with B and D, having a single bit set + ConstantInt *CCst = dyn_cast(C); + if (!CCst) return nullptr; + if (LHSCC != NEWCC) + CCst = dyn_cast( ConstantExpr::getXor(BCst, CCst) ); + ConstantInt *ECst = dyn_cast(E); + if (!ECst) return nullptr; + if (RHSCC != NEWCC) + ECst = dyn_cast( ConstantExpr::getXor(DCst, ECst) ); + ConstantInt* MCst = dyn_cast( + ConstantExpr::getAnd(ConstantExpr::getAnd(BCst, DCst), + ConstantExpr::getXor(CCst, ECst)) ); + // if there is a conflict we should actually return a false for the + // whole construct + if (!MCst->isZero()) + return nullptr; + Value *newOr1 = Builder->CreateOr(B, D); + Value *newOr2 = ConstantExpr::getOr(CCst, ECst); + Value *newAnd = Builder->CreateAnd(A, newOr1); + return Builder->CreateICmp(NEWCC, newAnd, newOr2); + } + return nullptr; +} + /// FoldAndOfICmps - Fold (icmp)&(icmp) if possible. Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate(); @@ -448,16 +801,20 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1); unsigned Code = getICmpCode(LHS) & getICmpCode(RHS); bool isSigned = LHS->isSigned() || RHS->isSigned(); - return getICmpValue(isSigned, Code, Op0, Op1, Builder); + return getNewICmpValue(isSigned, Code, Op0, Op1, Builder); } } - + + // handle (roughly): (icmp eq (A & B), C) & (icmp eq (A & D), E) + if (Value *V = foldLogOpOfMaskedICmps(LHS, RHS, true, Builder)) + return V; + // This only handles icmp of constants: (icmp1 A, C1) & (icmp2 B, C2). Value *Val = LHS->getOperand(0), *Val2 = RHS->getOperand(0); ConstantInt *LHSCst = dyn_cast(LHS->getOperand(1)); ConstantInt *RHSCst = dyn_cast(RHS->getOperand(1)); - if (LHSCst == 0 || RHSCst == 0) return 0; - + if (!LHSCst || !RHSCst) return nullptr; + if (LHSCst == RHSCst && LHSCC == RHSCC) { // (icmp ult A, C) & (icmp ult B, C) --> (icmp ult (A|B), C) // where C is a power of 2 @@ -466,57 +823,83 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { Value *NewOr = Builder->CreateOr(Val, Val2); return Builder->CreateICmp(LHSCC, NewOr, LHSCst); } - + // (icmp eq A, 0) & (icmp eq B, 0) --> (icmp eq (A|B), 0) if (LHSCC == ICmpInst::ICMP_EQ && LHSCst->isZero()) { Value *NewOr = Builder->CreateOr(Val, Val2); return Builder->CreateICmp(LHSCC, NewOr, LHSCst); } - - // (icmp ne (A & C1), 0) & (icmp ne (A & C2), 0) --> - // (icmp eq (A & (C1|C2)), (C1|C2)) - if (LHSCC == ICmpInst::ICMP_NE && LHSCst->isZero()) { - Instruction *I1 = dyn_cast(Val); - Instruction *I2 = dyn_cast(Val2); - if (I1 && I1->getOpcode() == Instruction::And && - I2 && I2->getOpcode() == Instruction::And && - I1->getOperand(0) == I1->getOperand(0)) { - ConstantInt *CI1 = dyn_cast(I1->getOperand(1)); - ConstantInt *CI2 = dyn_cast(I2->getOperand(1)); - if (CI1 && !CI1->isZero() && CI2 && !CI2->isZero() && - CI1->getValue().operator&(CI2->getValue()) == 0) { - Constant *ConstOr = ConstantExpr::getOr(CI1, CI2); - Value *NewAnd = Builder->CreateAnd(I1->getOperand(0), ConstOr); - return Builder->CreateICmp(ICmpInst::ICMP_EQ, NewAnd, ConstOr); - } + } + + // (trunc x) == C1 & (and x, CA) == C2 -> (and x, CA|CMAX) == C1|C2 + // where CMAX is the all ones value for the truncated type, + // iff the lower bits of C2 and CA are zero. + if (LHSCC == ICmpInst::ICMP_EQ && LHSCC == RHSCC && + LHS->hasOneUse() && RHS->hasOneUse()) { + Value *V; + ConstantInt *AndCst, *SmallCst = nullptr, *BigCst = nullptr; + + // (trunc x) == C1 & (and x, CA) == C2 + // (and x, CA) == C2 & (trunc x) == C1 + if (match(Val2, m_Trunc(m_Value(V))) && + match(Val, m_And(m_Specific(V), m_ConstantInt(AndCst)))) { + SmallCst = RHSCst; + BigCst = LHSCst; + } else if (match(Val, m_Trunc(m_Value(V))) && + match(Val2, m_And(m_Specific(V), m_ConstantInt(AndCst)))) { + SmallCst = LHSCst; + BigCst = RHSCst; + } + + if (SmallCst && BigCst) { + unsigned BigBitSize = BigCst->getType()->getBitWidth(); + unsigned SmallBitSize = SmallCst->getType()->getBitWidth(); + + // Check that the low bits are zero. + APInt Low = APInt::getLowBitsSet(BigBitSize, SmallBitSize); + if ((Low & AndCst->getValue()) == 0 && (Low & BigCst->getValue()) == 0) { + Value *NewAnd = Builder->CreateAnd(V, Low | AndCst->getValue()); + APInt N = SmallCst->getValue().zext(BigBitSize) | BigCst->getValue(); + Value *NewVal = ConstantInt::get(AndCst->getType()->getContext(), N); + return Builder->CreateICmp(LHSCC, NewAnd, NewVal); } } } - + // From here on, we only handle: // (icmp1 A, C1) & (icmp2 A, C2) --> something simpler. - if (Val != Val2) return 0; - + if (Val != Val2) return nullptr; + // ICMP_[US][GL]E X, CST is folded to ICMP_[US][GL]T elsewhere. if (LHSCC == ICmpInst::ICMP_UGE || LHSCC == ICmpInst::ICMP_ULE || RHSCC == ICmpInst::ICMP_UGE || RHSCC == ICmpInst::ICMP_ULE || LHSCC == ICmpInst::ICMP_SGE || LHSCC == ICmpInst::ICMP_SLE || RHSCC == ICmpInst::ICMP_SGE || RHSCC == ICmpInst::ICMP_SLE) - return 0; - + return nullptr; + + // Make a constant range that's the intersection of the two icmp ranges. + // If the intersection is empty, we know that the result is false. + ConstantRange LHSRange = + ConstantRange::makeICmpRegion(LHSCC, LHSCst->getValue()); + ConstantRange RHSRange = + ConstantRange::makeICmpRegion(RHSCC, RHSCst->getValue()); + + if (LHSRange.intersectWith(RHSRange).isEmptySet()) + return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0); + // We can't fold (ugt x, C) & (sgt x, C2). if (!PredicatesFoldable(LHSCC, RHSCC)) - return 0; - + return nullptr; + // Ensure that the larger constant is on the RHS. bool ShouldSwap; if (CmpInst::isSigned(LHSCC) || - (ICmpInst::isEquality(LHSCC) && + (ICmpInst::isEquality(LHSCC) && CmpInst::isSigned(RHSCC))) ShouldSwap = LHSCst->getValue().sgt(RHSCst->getValue()); else ShouldSwap = LHSCst->getValue().ugt(RHSCst->getValue()); - + if (ShouldSwap) { std::swap(LHS, RHS); std::swap(LHSCst, RHSCst); @@ -526,8 +909,8 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { // At this point, we know we have two icmp instructions // comparing a value against two constants and and'ing the result // together. Because of the above check, we know that we only have - // icmp eq, icmp ne, icmp [su]lt, and icmp [SU]gt here. We also know - // (from the icmp folding check above), that the two constants + // icmp eq, icmp ne, icmp [su]lt, and icmp [SU]gt here. We also know + // (from the icmp folding check above), that the two constants // are not equal and that the larger constant is on the RHS assert(LHSCst != RHSCst && "Compares not folded above?"); @@ -536,10 +919,6 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { case ICmpInst::ICMP_EQ: switch (RHSCC) { default: llvm_unreachable("Unknown integer condition code!"); - case ICmpInst::ICMP_EQ: // (X == 13 & X == 15) -> false - case ICmpInst::ICMP_UGT: // (X == 13 & X > 15) -> false - case ICmpInst::ICMP_SGT: // (X == 13 & X > 15) -> false - return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0); case ICmpInst::ICMP_NE: // (X == 13 & X != 15) -> X == 13 case ICmpInst::ICMP_ULT: // (X == 13 & X < 15) -> X == 13 case ICmpInst::ICMP_SLT: // (X == 13 & X < 15) -> X == 13 @@ -561,10 +940,15 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { case ICmpInst::ICMP_SGT: // (X != 13 & X s> 15) -> X s> 15 return RHS; case ICmpInst::ICMP_NE: + // Special case to get the ordering right when the values wrap around + // zero. + if (LHSCst->getValue() == 0 && RHSCst->getValue().isAllOnesValue()) + std::swap(LHSCst, RHSCst); if (LHSCst == SubOne(RHSCst)){// (X != 13 & X != 14) -> X-13 >u 1 Constant *AddCST = ConstantExpr::getNeg(LHSCst); Value *Add = Builder->CreateAdd(Val, AddCST, Val->getName()+".off"); - return Builder->CreateICmpUGT(Add, ConstantInt::get(Add->getType(), 1)); + return Builder->CreateICmpUGT(Add, ConstantInt::get(Add->getType(), 1), + Val->getName()+".cmp"); } break; // (X != 13 & X != 15) -> no change } @@ -587,9 +971,6 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { case ICmpInst::ICMP_SLT: switch (RHSCC) { default: llvm_unreachable("Unknown integer condition code!"); - case ICmpInst::ICMP_EQ: // (X s< 13 & X == 15) -> false - case ICmpInst::ICMP_SGT: // (X s< 13 & X s> 15) -> false - return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0); case ICmpInst::ICMP_UGT: // (X s< 13 & X u> 15) -> no change break; case ICmpInst::ICMP_NE: // (X s< 13 & X != 15) -> X < 13 @@ -636,8 +1017,8 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { } break; } - - return 0; + + return nullptr; } /// FoldAndOfFCmps - Optimize (fcmp)&(fcmp). NOTE: Unlike the rest of @@ -646,35 +1027,38 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { Value *InstCombiner::FoldAndOfFCmps(FCmpInst *LHS, FCmpInst *RHS) { if (LHS->getPredicate() == FCmpInst::FCMP_ORD && RHS->getPredicate() == FCmpInst::FCMP_ORD) { + if (LHS->getOperand(0)->getType() != RHS->getOperand(0)->getType()) + return nullptr; + // (fcmp ord x, c) & (fcmp ord y, c) -> (fcmp ord x, y) if (ConstantFP *LHSC = dyn_cast(LHS->getOperand(1))) if (ConstantFP *RHSC = dyn_cast(RHS->getOperand(1))) { // If either of the constants are nans, then the whole thing returns // false. if (LHSC->getValueAPF().isNaN() || RHSC->getValueAPF().isNaN()) - return ConstantInt::getFalse(LHS->getContext()); + return Builder->getFalse(); return Builder->CreateFCmpORD(LHS->getOperand(0), RHS->getOperand(0)); } - + // Handle vector zeros. This occurs because the canonical form of // "fcmp ord x,x" is "fcmp ord x, 0". if (isa(LHS->getOperand(1)) && isa(RHS->getOperand(1))) return Builder->CreateFCmpORD(LHS->getOperand(0), RHS->getOperand(0)); - return 0; + return nullptr; } - + Value *Op0LHS = LHS->getOperand(0), *Op0RHS = LHS->getOperand(1); Value *Op1LHS = RHS->getOperand(0), *Op1RHS = RHS->getOperand(1); FCmpInst::Predicate Op0CC = LHS->getPredicate(), Op1CC = RHS->getPredicate(); - - + + if (Op0LHS == Op1RHS && Op0RHS == Op1LHS) { // Swap RHS operands to match LHS. Op1CC = FCmpInst::getSwappedPredicate(Op1CC); std::swap(Op1LHS, Op1RHS); } - + if (Op0LHS == Op1LHS && Op0RHS == Op1RHS) { // Simplify (fcmp cc0 x, y) & (fcmp cc1 x, y). if (Op0CC == Op1CC) @@ -685,24 +1069,28 @@ Value *InstCombiner::FoldAndOfFCmps(FCmpInst *LHS, FCmpInst *RHS) { return RHS; if (Op1CC == FCmpInst::FCMP_TRUE) return LHS; - + bool Op0Ordered; bool Op1Ordered; unsigned Op0Pred = getFCmpCode(Op0CC, Op0Ordered); unsigned Op1Pred = getFCmpCode(Op1CC, Op1Ordered); + // uno && ord -> false + if (Op0Pred == 0 && Op1Pred == 0 && Op0Ordered != Op1Ordered) + return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0); if (Op1Pred == 0) { std::swap(LHS, RHS); std::swap(Op0Pred, Op1Pred); std::swap(Op0Ordered, Op1Ordered); } if (Op0Pred == 0) { - // uno && ueq -> uno && (uno || eq) -> ueq + // uno && ueq -> uno && (uno || eq) -> uno // ord && olt -> ord && (ord && lt) -> olt - if (Op0Ordered == Op1Ordered) + if (!Op0Ordered && (Op0Ordered == Op1Ordered)) + return LHS; + if (Op0Ordered && (Op0Ordered == Op1Ordered)) return RHS; - + // uno && oeq -> uno && (ord && eq) -> false - // uno && ord -> false if (!Op0Ordered) return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0); // ord && ueq -> ord && (uno || eq) -> oeq @@ -710,25 +1098,31 @@ Value *InstCombiner::FoldAndOfFCmps(FCmpInst *LHS, FCmpInst *RHS) { } } - return 0; + return nullptr; } Instruction *InstCombiner::visitAnd(BinaryOperator &I) { - bool Changed = SimplifyCommutative(I); + bool Changed = SimplifyAssociativeOrCommutative(I); Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1); - if (Value *V = SimplifyAndInst(Op0, Op1, TD)) + if (Value *V = SimplifyVectorOp(I)) + return ReplaceInstUsesWith(I, V); + + if (Value *V = SimplifyAndInst(Op0, Op1, DL)) + return ReplaceInstUsesWith(I, V); + + // (A|B)&(A|C) -> A|(B&C) etc + if (Value *V = SimplifyUsingDistributiveLaws(I)) return ReplaceInstUsesWith(I, V); - // See if we can simplify any instructions used by the instruction whose sole + // See if we can simplify any instructions used by the instruction whose sole // purpose is to compute bits we don't care about. if (SimplifyDemandedInstructionBits(I)) - return &I; + return &I; if (ConstantInt *AndRHS = dyn_cast(Op1)) { const APInt &AndRHSMask = AndRHS->getValue(); - APInt NotAndRHS(~AndRHSMask); // Optimize a variety of ((val OP C1) & C2) combinations... if (BinaryOperator *Op0I = dyn_cast(Op0)) { @@ -737,10 +1131,11 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) { switch (Op0I->getOpcode()) { default: break; case Instruction::Xor: - case Instruction::Or: + case Instruction::Or: { // If the mask is only needed on one incoming arm, push it up. if (!Op0I->hasOneUse()) break; - + + APInt NotAndRHS(~AndRHSMask); if (MaskedValueIsZero(Op0LHS, NotAndRHS)) { // Not masking anything out for the LHS, move to RHS. Value *NewRHS = Builder->CreateAnd(Op0RHS, AndRHS, @@ -756,6 +1151,7 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) { } break; + } case Instruction::Add: // ((A & N) + B) & AndRHS -> (A + B) & AndRHS iff N&AndRHS == AndRHS. // ((A | N) + B) & AndRHS -> (A + B) & AndRHS iff N&AndRHS == 0 @@ -775,14 +1171,12 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) { // (A - N) & AndRHS -> -N & AndRHS iff A&AndRHS==0 and AndRHS // has 1's for all bits that the subtraction with A might affect. - if (Op0I->hasOneUse()) { + if (Op0I->hasOneUse() && !match(Op0LHS, m_Zero())) { uint32_t BitWidth = AndRHSMask.getBitWidth(); uint32_t Zeros = AndRHSMask.countLeadingZeros(); APInt Mask = APInt::getLowBitsSet(BitWidth, BitWidth - Zeros); - ConstantInt *A = dyn_cast(Op0LHS); - if (!(A && A->isZero()) && // avoid infinite recursion. - MaskedValueIsZero(Op0LHS, Mask)) { + if (MaskedValueIsZero(Op0LHS, Mask)) { Value *NewNeg = Builder->CreateNeg(Op0RHS); return BinaryOperator::CreateAnd(NewNeg, AndRHS); } @@ -804,35 +1198,21 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) { if (ConstantInt *Op0CI = dyn_cast(Op0I->getOperand(1))) if (Instruction *Res = OptAndOp(Op0I, Op0CI, AndRHS, I)) return Res; - } else if (CastInst *CI = dyn_cast(Op0)) { - // If this is an integer truncation or change from signed-to-unsigned, and - // if the source is an and/or with immediate, transform it. This - // frequently occurs for bitfield accesses. - if (Instruction *CastOp = dyn_cast(CI->getOperand(0))) { - if ((isa(CI) || isa(CI)) && - CastOp->getNumOperands() == 2) - if (ConstantInt *AndCI =dyn_cast(CastOp->getOperand(1))){ - if (CastOp->getOpcode() == Instruction::And) { - // Change: and (cast (and X, C1) to T), C2 - // into : and (cast X to T), trunc_or_bitcast(C1)&C2 - // This will fold the two constants together, which may allow - // other simplifications. - Value *NewCast = Builder->CreateTruncOrBitCast( - CastOp->getOperand(0), I.getType(), - CastOp->getName()+".shrunk"); - // trunc_or_bitcast(C1)&C2 - Constant *C3 = ConstantExpr::getTruncOrBitCast(AndCI,I.getType()); - C3 = ConstantExpr::getAnd(C3, AndRHS); - return BinaryOperator::CreateAnd(NewCast, C3); - } else if (CastOp->getOpcode() == Instruction::Or) { - // Change: and (cast (or X, C1) to T), C2 - // into : trunc(C1)&C2 iff trunc(C1)&C2 == C2 - Constant *C3 = ConstantExpr::getTruncOrBitCast(AndCI,I.getType()); - if (ConstantExpr::getAnd(C3, AndRHS) == AndRHS) - // trunc(C1)&C2 - return ReplaceInstUsesWith(I, AndRHS); - } - } + } + + // If this is an integer truncation, and if the source is an 'and' with + // immediate, transform it. This frequently occurs for bitfield accesses. + { + Value *X = nullptr; ConstantInt *YC = nullptr; + if (match(Op0, m_Trunc(m_And(m_Value(X), m_ConstantInt(YC))))) { + // Change: and (trunc (and X, YC) to T), C2 + // into : and (trunc X to T), trunc(YC) & C2 + // This will fold the two constants together, which may allow + // other simplifications. + Value *NewCast = Builder->CreateTrunc(X, I.getType(), "and.shrunk"); + Constant *C3 = ConstantExpr::getTrunc(YC, I.getType()); + C3 = ConstantExpr::getAnd(C3, AndRHS); + return BinaryOperator::CreateAnd(NewCast, C3); } } @@ -856,39 +1236,44 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) { } { - Value *A = 0, *B = 0, *C = 0, *D = 0; + Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr; // (A|B) & ~(A&B) -> A^B if (match(Op0, m_Or(m_Value(A), m_Value(B))) && match(Op1, m_Not(m_And(m_Value(C), m_Value(D)))) && ((A == C && B == D) || (A == D && B == C))) return BinaryOperator::CreateXor(A, B); - + // ~(A&B) & (A|B) -> A^B if (match(Op1, m_Or(m_Value(A), m_Value(B))) && match(Op0, m_Not(m_And(m_Value(C), m_Value(D)))) && ((A == C && B == D) || (A == D && B == C))) return BinaryOperator::CreateXor(A, B); - - if (Op0->hasOneUse() && - match(Op0, m_Xor(m_Value(A), m_Value(B)))) { - if (A == Op1) { // (A^B)&A -> A&(A^B) - I.swapOperands(); // Simplify below - std::swap(Op0, Op1); - } else if (B == Op1) { // (A^B)&B -> B&(B^A) - cast(Op0)->swapOperands(); - I.swapOperands(); // Simplify below - std::swap(Op0, Op1); + + // A&(A^B) => A & ~B + { + Value *tmpOp0 = Op0; + Value *tmpOp1 = Op1; + if (Op0->hasOneUse() && + match(Op0, m_Xor(m_Value(A), m_Value(B)))) { + if (A == Op1 || B == Op1 ) { + tmpOp1 = Op0; + tmpOp0 = Op1; + // Simplify below + } } - } - if (Op1->hasOneUse() && - match(Op1, m_Xor(m_Value(A), m_Value(B)))) { - if (B == Op0) { // B&(A^B) -> B&(B^A) - cast(Op1)->swapOperands(); - std::swap(A, B); + if (tmpOp1->hasOneUse() && + match(tmpOp1, m_Xor(m_Value(A), m_Value(B)))) { + if (B == tmpOp0) { + std::swap(A, B); + } + // Notice that the patten (A&(~B)) is actually (A&(-1^B)), so if + // A is originally -1 (or a vector of -1 and undefs), then we enter + // an endless loop. By checking that A is non-constant we ensure that + // we will never get to the loop. + if (A == tmpOp0 && !isa(A)) // A&(A^B) -> A & ~B + return BinaryOperator::CreateAnd(A, Builder->CreateNot(B)); } - if (A == Op0) // A&(A^B) -> A & ~B - return BinaryOperator::CreateAnd(A, Builder->CreateNot(B, "tmp")); } // (A&((~A)|B)) -> A&B @@ -899,42 +1284,42 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) { match(Op1, m_Or(m_Value(A), m_Not(m_Specific(Op0))))) return BinaryOperator::CreateAnd(A, Op0); } - + if (ICmpInst *RHS = dyn_cast(Op1)) if (ICmpInst *LHS = dyn_cast(Op0)) if (Value *Res = FoldAndOfICmps(LHS, RHS)) return ReplaceInstUsesWith(I, Res); - + // If and'ing two fcmp, try combine them into one. if (FCmpInst *LHS = dyn_cast(I.getOperand(0))) if (FCmpInst *RHS = dyn_cast(I.getOperand(1))) if (Value *Res = FoldAndOfFCmps(LHS, RHS)) return ReplaceInstUsesWith(I, Res); - - + + // fold (and (cast A), (cast B)) -> (cast (and A, B)) if (CastInst *Op0C = dyn_cast(Op0)) if (CastInst *Op1C = dyn_cast(Op1)) { - const Type *SrcTy = Op0C->getOperand(0)->getType(); + Type *SrcTy = Op0C->getOperand(0)->getType(); if (Op0C->getOpcode() == Op1C->getOpcode() && // same cast kind ? SrcTy == Op1C->getOperand(0)->getType() && SrcTy->isIntOrIntVectorTy()) { Value *Op0COp = Op0C->getOperand(0), *Op1COp = Op1C->getOperand(0); - + // Only do this if the casts both really cause code to be generated. if (ShouldOptimizeCast(Op0C->getOpcode(), Op0COp, I.getType()) && ShouldOptimizeCast(Op1C->getOpcode(), Op1COp, I.getType())) { Value *NewOp = Builder->CreateAnd(Op0COp, Op1COp, I.getName()); return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType()); } - + // If this is and(cast(icmp), cast(icmp)), try to fold this even if the // cast is otherwise not optimizable. This happens for vector sexts. if (ICmpInst *RHS = dyn_cast(Op1COp)) if (ICmpInst *LHS = dyn_cast(Op0COp)) if (Value *Res = FoldAndOfICmps(LHS, RHS)) return CastInst::Create(Op0C->getOpcode(), Res, I.getType()); - + // If this is and(cast(fcmp), cast(fcmp)), try to fold this even if the // cast is otherwise not optimizable. This happens for vector sexts. if (FCmpInst *RHS = dyn_cast(Op1COp)) @@ -943,22 +1328,50 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) { return CastInst::Create(Op0C->getOpcode(), Res, I.getType()); } } - + // (X >> Z) & (Y >> Z) -> (X&Y) >> Z for all shifts. if (BinaryOperator *SI1 = dyn_cast(Op1)) { if (BinaryOperator *SI0 = dyn_cast(Op0)) - if (SI0->isShift() && SI0->getOpcode() == SI1->getOpcode() && + if (SI0->isShift() && SI0->getOpcode() == SI1->getOpcode() && SI0->getOperand(1) == SI1->getOperand(1) && (SI0->hasOneUse() || SI1->hasOneUse())) { Value *NewOp = Builder->CreateAnd(SI0->getOperand(0), SI1->getOperand(0), SI0->getName()); - return BinaryOperator::Create(SI1->getOpcode(), NewOp, + return BinaryOperator::Create(SI1->getOpcode(), NewOp, SI1->getOperand(1)); } } - return Changed ? &I : 0; + { + Value *X = nullptr; + bool OpsSwapped = false; + // Canonicalize SExt or Not to the LHS + if (match(Op1, m_SExt(m_Value())) || + match(Op1, m_Not(m_Value()))) { + std::swap(Op0, Op1); + OpsSwapped = true; + } + + // Fold (and (sext bool to A), B) --> (select bool, B, 0) + if (match(Op0, m_SExt(m_Value(X))) && + X->getType()->getScalarType()->isIntegerTy(1)) { + Value *Zero = Constant::getNullValue(Op1->getType()); + return SelectInst::Create(X, Op1, Zero); + } + + // Fold (and ~(sext bool to A), B) --> (select bool, 0, B) + if (match(Op0, m_Not(m_SExt(m_Value(X)))) && + X->getType()->getScalarType()->isIntegerTy(1)) { + Value *Zero = Constant::getNullValue(Op0->getType()); + return SelectInst::Create(X, Zero, Op1); + } + + if (OpsSwapped) + std::swap(Op0, Op1); + } + + return Changed ? &I : nullptr; } /// CollectBSwapParts - Analyze the specified subexpression and see if it is @@ -985,7 +1398,7 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) { /// always in the local (OverallLeftShift) coordinate space. /// static bool CollectBSwapParts(Value *V, int OverallLeftShift, uint32_t ByteMask, - SmallVector &ByteValues) { + SmallVectorImpl &ByteValues) { if (Instruction *I = dyn_cast(V)) { // If this is an or instruction, it may be an inner node of the bswap. if (I->getOpcode() == Instruction::Or) { @@ -994,11 +1407,11 @@ static bool CollectBSwapParts(Value *V, int OverallLeftShift, uint32_t ByteMask, CollectBSwapParts(I->getOperand(1), OverallLeftShift, ByteMask, ByteValues); } - + // If this is a logical shift by a constant multiple of 8, recurse with // OverallLeftShift and ByteMask adjusted. if (I->isLogicalShift() && isa(I->getOperand(1))) { - unsigned ShAmt = + unsigned ShAmt = cast(I->getOperand(1))->getLimitedValue(~0U); // Ensure the shift amount is defined and of a byte value. if ((ShAmt & 7) || (ShAmt > 8*ByteValues.size())) @@ -1019,7 +1432,7 @@ static bool CollectBSwapParts(Value *V, int OverallLeftShift, uint32_t ByteMask, if (OverallLeftShift >= (int)ByteValues.size()) return true; if (OverallLeftShift <= -(int)ByteValues.size()) return true; - return CollectBSwapParts(I->getOperand(0), OverallLeftShift, ByteMask, + return CollectBSwapParts(I->getOperand(0), OverallLeftShift, ByteMask, ByteValues); } @@ -1031,20 +1444,20 @@ static bool CollectBSwapParts(Value *V, int OverallLeftShift, uint32_t ByteMask, unsigned NumBytes = ByteValues.size(); APInt Byte(I->getType()->getPrimitiveSizeInBits(), 255); const APInt &AndMask = cast(I->getOperand(1))->getValue(); - + for (unsigned i = 0; i != NumBytes; ++i, Byte <<= 8) { // If this byte is masked out by a later operation, we don't care what // the and mask is. if ((ByteMask & (1 << i)) == 0) continue; - + // If the AndMask is all zeros for this byte, clear the bit. APInt MaskB = AndMask & Byte; if (MaskB == 0) { ByteMask &= ~(1U << i); continue; } - + // If the AndMask is not all ones for this byte, it's not a bytezap. if (MaskB != Byte) return true; @@ -1052,19 +1465,19 @@ static bool CollectBSwapParts(Value *V, int OverallLeftShift, uint32_t ByteMask, // Otherwise, this byte is kept. } - return CollectBSwapParts(I->getOperand(0), OverallLeftShift, ByteMask, + return CollectBSwapParts(I->getOperand(0), OverallLeftShift, ByteMask, ByteValues); } } - + // Okay, we got to something that isn't a shift, 'or' or 'and'. This must be // the input value to the bswap. Some observations: 1) if more than one byte // is demanded from this input, then it could not be successfully assembled // into a byteswap. At least one of the two bytes would not be aligned with // their ultimate destination. if (!isPowerOf2_32(ByteMask)) return true; - unsigned InputByteNo = CountTrailingZeros_32(ByteMask); - + unsigned InputByteNo = countTrailingZeros(ByteMask); + // 2) The input and ultimate destinations must line up: if byte 3 of an i32 // is demanded, it needs to go into byte 0 of the result. This means that the // byte needs to be shifted until it lands in the right byte bucket. The @@ -1072,14 +1485,9 @@ static bool CollectBSwapParts(Value *V, int OverallLeftShift, uint32_t ByteMask, // part of the value (e.g. byte 3) then it must be shifted right. If from the // low part, it must be shifted left. unsigned DestByteNo = InputByteNo + OverallLeftShift; - if (InputByteNo < ByteValues.size()/2) { - if (ByteValues.size()-1-DestByteNo != InputByteNo) - return true; - } else { - if (ByteValues.size()-1-DestByteNo != InputByteNo) - return true; - } - + if (ByteValues.size()-1-DestByteNo != InputByteNo) + return true; + // If the destination byte value is already defined, the values are or'd // together, which isn't a bswap (unless it's an or of the same bits). if (ByteValues[DestByteNo] && ByteValues[DestByteNo] != V) @@ -1091,33 +1499,32 @@ static bool CollectBSwapParts(Value *V, int OverallLeftShift, uint32_t ByteMask, /// MatchBSwap - Given an OR instruction, check to see if this is a bswap idiom. /// If so, insert the new bswap intrinsic and return it. Instruction *InstCombiner::MatchBSwap(BinaryOperator &I) { - const IntegerType *ITy = dyn_cast(I.getType()); - if (!ITy || ITy->getBitWidth() % 16 || + IntegerType *ITy = dyn_cast(I.getType()); + if (!ITy || ITy->getBitWidth() % 16 || // ByteMask only allows up to 32-byte values. - ITy->getBitWidth() > 32*8) - return 0; // Can only bswap pairs of bytes. Can't do vectors. - + ITy->getBitWidth() > 32*8) + return nullptr; // Can only bswap pairs of bytes. Can't do vectors. + /// ByteValues - For each byte of the result, we keep track of which value /// defines each byte. SmallVector ByteValues; ByteValues.resize(ITy->getBitWidth()/8); - + // Try to find all the pieces corresponding to the bswap. uint32_t ByteMask = ~0U >> (32-ByteValues.size()); if (CollectBSwapParts(&I, 0, ByteMask, ByteValues)) - return 0; - + return nullptr; + // Check to see if all of the bytes come from the same value. Value *V = ByteValues[0]; - if (V == 0) return 0; // Didn't find a byte? Must be zero. - + if (!V) return nullptr; // Didn't find a byte? Must be zero. + // Check to make sure that all of the bytes come from the same value. for (unsigned i = 1, e = ByteValues.size(); i != e; ++i) if (ByteValues[i] != V) - return 0; - const Type *Tys[] = { ITy }; + return nullptr; Module *M = I.getParent()->getParent()->getParent(); - Function *F = Intrinsic::getDeclaration(M, Intrinsic::bswap, Tys, 1); + Function *F = Intrinsic::getDeclaration(M, Intrinsic::bswap, ITy); return CallInst::Create(F, V); } @@ -1127,29 +1534,62 @@ Instruction *InstCombiner::MatchBSwap(BinaryOperator &I) { static Instruction *MatchSelectFromAndOr(Value *A, Value *B, Value *C, Value *D) { // If A is not a select of -1/0, this cannot match. - Value *Cond = 0; + Value *Cond = nullptr; if (!match(A, m_SExt(m_Value(Cond))) || !Cond->getType()->isIntegerTy(1)) - return 0; + return nullptr; // ((cond?-1:0)&C) | (B&(cond?0:-1)) -> cond ? C : B. if (match(D, m_Not(m_SExt(m_Specific(Cond))))) return SelectInst::Create(Cond, C, B); if (match(D, m_SExt(m_Not(m_Specific(Cond))))) return SelectInst::Create(Cond, C, B); - + // ((cond?-1:0)&C) | ((cond?0:-1)&D) -> cond ? C : D. if (match(B, m_Not(m_SExt(m_Specific(Cond))))) return SelectInst::Create(Cond, C, D); if (match(B, m_SExt(m_Not(m_Specific(Cond))))) return SelectInst::Create(Cond, C, D); - return 0; + return nullptr; } /// FoldOrOfICmps - Fold (icmp)|(icmp) if possible. Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS) { ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate(); + // Fold (iszero(A & K1) | iszero(A & K2)) -> (A & (K1 | K2)) != (K1 | K2) + // if K1 and K2 are a one-bit mask. + ConstantInt *LHSCst = dyn_cast(LHS->getOperand(1)); + ConstantInt *RHSCst = dyn_cast(RHS->getOperand(1)); + + if (LHS->getPredicate() == ICmpInst::ICMP_EQ && LHSCst && LHSCst->isZero() && + RHS->getPredicate() == ICmpInst::ICMP_EQ && RHSCst && RHSCst->isZero()) { + + BinaryOperator *LAnd = dyn_cast(LHS->getOperand(0)); + BinaryOperator *RAnd = dyn_cast(RHS->getOperand(0)); + if (LAnd && RAnd && LAnd->hasOneUse() && RHS->hasOneUse() && + LAnd->getOpcode() == Instruction::And && + RAnd->getOpcode() == Instruction::And) { + + Value *Mask = nullptr; + Value *Masked = nullptr; + if (LAnd->getOperand(0) == RAnd->getOperand(0) && + isKnownToBeAPowerOfTwo(LAnd->getOperand(1)) && + isKnownToBeAPowerOfTwo(RAnd->getOperand(1))) { + Mask = Builder->CreateOr(LAnd->getOperand(1), RAnd->getOperand(1)); + Masked = Builder->CreateAnd(LAnd->getOperand(0), Mask); + } else if (LAnd->getOperand(1) == RAnd->getOperand(1) && + isKnownToBeAPowerOfTwo(LAnd->getOperand(0)) && + isKnownToBeAPowerOfTwo(RAnd->getOperand(0))) { + Mask = Builder->CreateOr(LAnd->getOperand(0), RAnd->getOperand(0)); + Masked = Builder->CreateAnd(LAnd->getOperand(1), Mask); + } + + if (Masked) + return Builder->CreateICmp(ICmpInst::ICMP_NE, Masked, Mask); + } + } + // (icmp1 A, B) | (icmp2 A, B) --> (icmp3 A, B) if (PredicatesFoldable(LHSCC, RHSCC)) { if (LHS->getOperand(0) == RHS->getOperand(1) && @@ -1160,72 +1600,92 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS) { Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1); unsigned Code = getICmpCode(LHS) | getICmpCode(RHS); bool isSigned = LHS->isSigned() || RHS->isSigned(); - return getICmpValue(isSigned, Code, Op0, Op1, Builder); + return getNewICmpValue(isSigned, Code, Op0, Op1, Builder); } } - - // This only handles icmp of constants: (icmp1 A, C1) | (icmp2 B, C2). + + // handle (roughly): + // (icmp ne (A & B), C) | (icmp ne (A & D), E) + if (Value *V = foldLogOpOfMaskedICmps(LHS, RHS, false, Builder)) + return V; + Value *Val = LHS->getOperand(0), *Val2 = RHS->getOperand(0); - ConstantInt *LHSCst = dyn_cast(LHS->getOperand(1)); - ConstantInt *RHSCst = dyn_cast(RHS->getOperand(1)); - if (LHSCst == 0 || RHSCst == 0) return 0; - - // (icmp ne A, 0) | (icmp ne B, 0) --> (icmp ne (A|B), 0) - if (LHSCst == RHSCst && LHSCC == RHSCC && - LHSCC == ICmpInst::ICMP_NE && LHSCst->isZero()) { - Value *NewOr = Builder->CreateOr(Val, Val2); - return Builder->CreateICmp(LHSCC, NewOr, LHSCst); - } - - // (icmp eq (A & C1), 0) | (icmp eq (A & C2), 0) --> - // (icmp ne (A & (C1|C2)), (C1|C2)) - if (LHSCC == ICmpInst::ICMP_EQ && LHSCst->isZero()) { - Instruction *I1 = dyn_cast(Val); - Instruction *I2 = dyn_cast(Val2); - if (I1 && I1->getOpcode() == Instruction::And && - I2 && I2->getOpcode() == Instruction::And && - I1->getOperand(0) == I1->getOperand(0)) { - ConstantInt *CI1 = dyn_cast(I1->getOperand(1)); - ConstantInt *CI2 = dyn_cast(I2->getOperand(1)); - if (CI1 && !CI1->isZero() && CI2 && !CI2->isZero() && - CI1->getValue().operator&(CI2->getValue()) == 0) { - Constant *ConstOr = ConstantExpr::getOr(CI1, CI2); - Value *NewAnd = Builder->CreateAnd(I1->getOperand(0), ConstOr); - return Builder->CreateICmp(ICmpInst::ICMP_NE, NewAnd, ConstOr); - } + if (LHS->hasOneUse() || RHS->hasOneUse()) { + // (icmp eq B, 0) | (icmp ult A, B) -> (icmp ule A, B-1) + // (icmp eq B, 0) | (icmp ugt B, A) -> (icmp ule A, B-1) + Value *A = nullptr, *B = nullptr; + if (LHSCC == ICmpInst::ICMP_EQ && LHSCst && LHSCst->isZero()) { + B = Val; + if (RHSCC == ICmpInst::ICMP_ULT && Val == RHS->getOperand(1)) + A = Val2; + else if (RHSCC == ICmpInst::ICMP_UGT && Val == Val2) + A = RHS->getOperand(1); + } + // (icmp ult A, B) | (icmp eq B, 0) -> (icmp ule A, B-1) + // (icmp ugt B, A) | (icmp eq B, 0) -> (icmp ule A, B-1) + else if (RHSCC == ICmpInst::ICMP_EQ && RHSCst && RHSCst->isZero()) { + B = Val2; + if (LHSCC == ICmpInst::ICMP_ULT && Val2 == LHS->getOperand(1)) + A = Val; + else if (LHSCC == ICmpInst::ICMP_UGT && Val2 == Val) + A = LHS->getOperand(1); + } + if (A && B) + return Builder->CreateICmp( + ICmpInst::ICMP_UGE, + Builder->CreateAdd(B, ConstantInt::getSigned(B->getType(), -1)), A); + } + + // This only handles icmp of constants: (icmp1 A, C1) | (icmp2 B, C2). + if (!LHSCst || !RHSCst) return nullptr; + + if (LHSCst == RHSCst && LHSCC == RHSCC) { + // (icmp ne A, 0) | (icmp ne B, 0) --> (icmp ne (A|B), 0) + if (LHSCC == ICmpInst::ICMP_NE && LHSCst->isZero()) { + Value *NewOr = Builder->CreateOr(Val, Val2); + return Builder->CreateICmp(LHSCC, NewOr, LHSCst); } } - + + // (icmp ult (X + CA), C1) | (icmp eq X, C2) -> (icmp ule (X + CA), C1) + // iff C2 + CA == C1. + if (LHSCC == ICmpInst::ICMP_ULT && RHSCC == ICmpInst::ICMP_EQ) { + ConstantInt *AddCst; + if (match(Val, m_Add(m_Specific(Val2), m_ConstantInt(AddCst)))) + if (RHSCst->getValue() + AddCst->getValue() == LHSCst->getValue()) + return Builder->CreateICmpULE(Val, LHSCst); + } + // From here on, we only handle: // (icmp1 A, C1) | (icmp2 A, C2) --> something simpler. - if (Val != Val2) return 0; - + if (Val != Val2) return nullptr; + // ICMP_[US][GL]E X, CST is folded to ICMP_[US][GL]T elsewhere. if (LHSCC == ICmpInst::ICMP_UGE || LHSCC == ICmpInst::ICMP_ULE || RHSCC == ICmpInst::ICMP_UGE || RHSCC == ICmpInst::ICMP_ULE || LHSCC == ICmpInst::ICMP_SGE || LHSCC == ICmpInst::ICMP_SLE || RHSCC == ICmpInst::ICMP_SGE || RHSCC == ICmpInst::ICMP_SLE) - return 0; - + return nullptr; + // We can't fold (ugt x, C) | (sgt x, C2). if (!PredicatesFoldable(LHSCC, RHSCC)) - return 0; - + return nullptr; + // Ensure that the larger constant is on the RHS. bool ShouldSwap; if (CmpInst::isSigned(LHSCC) || - (ICmpInst::isEquality(LHSCC) && + (ICmpInst::isEquality(LHSCC) && CmpInst::isSigned(RHSCC))) ShouldSwap = LHSCst->getValue().sgt(RHSCst->getValue()); else ShouldSwap = LHSCst->getValue().ugt(RHSCst->getValue()); - + if (ShouldSwap) { std::swap(LHS, RHS); std::swap(LHSCst, RHSCst); std::swap(LHSCC, RHSCC); } - + // At this point, we know we have two icmp instructions // comparing a value against two constants and or'ing the result // together. Because of the above check, we know that we only have @@ -1240,6 +1700,19 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS) { switch (RHSCC) { default: llvm_unreachable("Unknown integer condition code!"); case ICmpInst::ICMP_EQ: + if (LHS->getOperand(0) == RHS->getOperand(0)) { + // if LHSCst and RHSCst differ only by one bit: + // (A == C1 || A == C2) -> (A & ~(C1 ^ C2)) == C1 + assert(LHSCst->getValue().ule(LHSCst->getValue())); + + APInt Xor = LHSCst->getValue() ^ RHSCst->getValue(); + if (Xor.isPowerOf2()) { + Value *NegCst = Builder->getInt(~Xor); + Value *And = Builder->CreateAnd(LHS->getOperand(0), NegCst); + return Builder->CreateICmp(ICmpInst::ICMP_EQ, And, LHSCst); + } + } + if (LHSCst == SubOne(RHSCst)) { // (X == 13 | X == 14) -> X-13 CreateICmpULT(Add, AddCST); } + break; // (X == 13 | X == 15) -> no change case ICmpInst::ICMP_UGT: // (X == 13 | X u> 14) -> no change case ICmpInst::ICMP_SGT: // (X == 13 | X s> 14) -> no change @@ -1267,9 +1741,8 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS) { case ICmpInst::ICMP_NE: // (X != 13 | X != 15) -> true case ICmpInst::ICMP_ULT: // (X != 13 | X u< 15) -> true case ICmpInst::ICMP_SLT: // (X != 13 | X s< 15) -> true - return ConstantInt::getTrue(LHS->getContext()); + return Builder->getTrue(); } - break; case ICmpInst::ICMP_ULT: switch (RHSCC) { default: llvm_unreachable("Unknown integer condition code!"); @@ -1320,7 +1793,7 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS) { break; case ICmpInst::ICMP_NE: // (X u> 13 | X != 15) -> true case ICmpInst::ICMP_ULT: // (X u> 13 | X u< 15) -> true - return ConstantInt::getTrue(LHS->getContext()); + return Builder->getTrue(); case ICmpInst::ICMP_SLT: // (X u> 13 | X s< 15) -> no change break; } @@ -1335,13 +1808,13 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS) { break; case ICmpInst::ICMP_NE: // (X s> 13 | X != 15) -> true case ICmpInst::ICMP_SLT: // (X s> 13 | X s< 15) -> true - return ConstantInt::getTrue(LHS->getContext()); + return Builder->getTrue(); case ICmpInst::ICMP_ULT: // (X s> 13 | X u< 15) -> no change break; } break; } - return 0; + return nullptr; } /// FoldOrOfFCmps - Optimize (fcmp)|(fcmp). NOTE: Unlike the rest of @@ -1349,33 +1822,33 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS) { /// function. Value *InstCombiner::FoldOrOfFCmps(FCmpInst *LHS, FCmpInst *RHS) { if (LHS->getPredicate() == FCmpInst::FCMP_UNO && - RHS->getPredicate() == FCmpInst::FCMP_UNO && + RHS->getPredicate() == FCmpInst::FCMP_UNO && LHS->getOperand(0)->getType() == RHS->getOperand(0)->getType()) { if (ConstantFP *LHSC = dyn_cast(LHS->getOperand(1))) if (ConstantFP *RHSC = dyn_cast(RHS->getOperand(1))) { // If either of the constants are nans, then the whole thing returns // true. if (LHSC->getValueAPF().isNaN() || RHSC->getValueAPF().isNaN()) - return ConstantInt::getTrue(LHS->getContext()); - + return Builder->getTrue(); + // Otherwise, no need to compare the two constants, compare the // rest. return Builder->CreateFCmpUNO(LHS->getOperand(0), RHS->getOperand(0)); } - + // Handle vector zeros. This occurs because the canonical form of // "fcmp uno x,x" is "fcmp uno x, 0". if (isa(LHS->getOperand(1)) && isa(RHS->getOperand(1))) return Builder->CreateFCmpUNO(LHS->getOperand(0), RHS->getOperand(0)); - - return 0; + + return nullptr; } - + Value *Op0LHS = LHS->getOperand(0), *Op0RHS = LHS->getOperand(1); Value *Op1LHS = RHS->getOperand(0), *Op1RHS = RHS->getOperand(1); FCmpInst::Predicate Op0CC = LHS->getPredicate(), Op1CC = RHS->getPredicate(); - + if (Op0LHS == Op1RHS && Op0RHS == Op1LHS) { // Swap RHS operands to match LHS. Op1CC = FCmpInst::getSwappedPredicate(Op1CC); @@ -1401,7 +1874,7 @@ Value *InstCombiner::FoldOrOfFCmps(FCmpInst *LHS, FCmpInst *RHS) { return getFCmpValue(Op0Ordered, Op0Pred|Op1Pred, Op0LHS, Op0RHS, Builder); } } - return 0; + return nullptr; } /// FoldOrWithConstants - This helper function folds: @@ -1409,44 +1882,51 @@ Value *InstCombiner::FoldOrOfFCmps(FCmpInst *LHS, FCmpInst *RHS) { /// ((A | B) & C1) | (B & C2) /// /// into: -/// +/// /// (A & C1) | B /// /// when the XOR of the two constants is "all ones" (-1). Instruction *InstCombiner::FoldOrWithConstants(BinaryOperator &I, Value *Op, Value *A, Value *B, Value *C) { ConstantInt *CI1 = dyn_cast(C); - if (!CI1) return 0; + if (!CI1) return nullptr; - Value *V1 = 0; - ConstantInt *CI2 = 0; - if (!match(Op, m_And(m_Value(V1), m_ConstantInt(CI2)))) return 0; + Value *V1 = nullptr; + ConstantInt *CI2 = nullptr; + if (!match(Op, m_And(m_Value(V1), m_ConstantInt(CI2)))) return nullptr; APInt Xor = CI1->getValue() ^ CI2->getValue(); - if (!Xor.isAllOnesValue()) return 0; + if (!Xor.isAllOnesValue()) return nullptr; if (V1 == A || V1 == B) { Value *NewOp = Builder->CreateAnd((V1 == A) ? B : A, CI1); return BinaryOperator::CreateOr(NewOp, V1); } - return 0; + return nullptr; } Instruction *InstCombiner::visitOr(BinaryOperator &I) { - bool Changed = SimplifyCommutative(I); + bool Changed = SimplifyAssociativeOrCommutative(I); Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1); - if (Value *V = SimplifyOrInst(Op0, Op1, TD)) + if (Value *V = SimplifyVectorOp(I)) return ReplaceInstUsesWith(I, V); - // See if we can simplify any instructions used by the instruction whose sole + if (Value *V = SimplifyOrInst(Op0, Op1, DL)) + return ReplaceInstUsesWith(I, V); + + // (A&B)|(A&C) -> A&(B|C) etc + if (Value *V = SimplifyUsingDistributiveLaws(I)) + return ReplaceInstUsesWith(I, V); + + // See if we can simplify any instructions used by the instruction whose sole // purpose is to compute bits we don't care about. if (SimplifyDemandedInstructionBits(I)) return &I; if (ConstantInt *RHS = dyn_cast(Op1)) { - ConstantInt *C1 = 0; Value *X = 0; + ConstantInt *C1 = nullptr; Value *X = nullptr; // (X & C1) | C2 --> (X | C2) & (C1|C2) // iff (C1 & C2) == 0. if (match(Op0, m_And(m_Value(X), m_ConstantInt(C1))) && @@ -1454,9 +1934,8 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { Op0->hasOneUse()) { Value *Or = Builder->CreateOr(X, RHS); Or->takeName(Op0); - return BinaryOperator::CreateAnd(Or, - ConstantInt::get(I.getContext(), - RHS->getValue() | C1->getValue())); + return BinaryOperator::CreateAnd(Or, + Builder->getInt(RHS->getValue() | C1->getValue())); } // (X ^ C1) | C2 --> (X | C2) ^ (C1&~C2) @@ -1465,8 +1944,7 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { Value *Or = Builder->CreateOr(X, RHS); Or->takeName(Op0); return BinaryOperator::CreateXor(Or, - ConstantInt::get(I.getContext(), - C1->getValue() & ~RHS->getValue())); + Builder->getInt(C1->getValue() & ~RHS->getValue())); } // Try to fold constant and into select arguments. @@ -1479,19 +1957,19 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { return NV; } - Value *A = 0, *B = 0; - ConstantInt *C1 = 0, *C2 = 0; + Value *A = nullptr, *B = nullptr; + ConstantInt *C1 = nullptr, *C2 = nullptr; // (A | B) | C and A | (B | C) -> bswap if possible. // (A >> B) | (C << D) and (A << B) | (B >> C) -> bswap if possible. if (match(Op0, m_Or(m_Value(), m_Value())) || match(Op1, m_Or(m_Value(), m_Value())) || - (match(Op0, m_Shift(m_Value(), m_Value())) && - match(Op1, m_Shift(m_Value(), m_Value())))) { + (match(Op0, m_LogicalShift(m_Value(), m_Value())) && + match(Op1, m_LogicalShift(m_Value(), m_Value())))) { if (Instruction *BSwap = MatchBSwap(I)) return BSwap; } - + // (X^C)|Y -> (X|Y)^C iff Y&C == 0 if (Op0->hasOneUse() && match(Op0, m_Xor(m_Value(A), m_ConstantInt(C1))) && @@ -1511,10 +1989,10 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { } // (A & C)|(B & D) - Value *C = 0, *D = 0; + Value *C = nullptr, *D = nullptr; if (match(Op0, m_And(m_Value(A), m_Value(C))) && match(Op1, m_And(m_Value(B), m_Value(D)))) { - Value *V1 = 0, *V2 = 0, *V3 = 0; + Value *V1 = nullptr, *V2 = nullptr; C1 = dyn_cast(C); C2 = dyn_cast(D); if (C1 && C2) { // (A & C1)|(B & C2) @@ -1540,7 +2018,7 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { return ReplaceInstUsesWith(I, B); } } - + if ((C1->getValue() & C2->getValue()) == 0) { // ((V | N) & C1) | (V & C2) --> (V|N) & (C1|C2) // iff (C1&C2) == 0 and (N&~C1) == 0 @@ -1548,49 +2026,27 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { ((V1 == B && MaskedValueIsZero(V2, ~C1->getValue())) || // (V|N) (V2 == B && MaskedValueIsZero(V1, ~C1->getValue())))) // (N|V) return BinaryOperator::CreateAnd(A, - ConstantInt::get(A->getContext(), - C1->getValue()|C2->getValue())); + Builder->getInt(C1->getValue()|C2->getValue())); // Or commutes, try both ways. if (match(B, m_Or(m_Value(V1), m_Value(V2))) && ((V1 == A && MaskedValueIsZero(V2, ~C2->getValue())) || // (V|N) (V2 == A && MaskedValueIsZero(V1, ~C2->getValue())))) // (N|V) return BinaryOperator::CreateAnd(B, - ConstantInt::get(B->getContext(), - C1->getValue()|C2->getValue())); - + Builder->getInt(C1->getValue()|C2->getValue())); + // ((V|C3)&C1) | ((V|C4)&C2) --> (V|C3|C4)&(C1|C2) // iff (C1&C2) == 0 and (C3&~C1) == 0 and (C4&~C2) == 0. - ConstantInt *C3 = 0, *C4 = 0; + ConstantInt *C3 = nullptr, *C4 = nullptr; if (match(A, m_Or(m_Value(V1), m_ConstantInt(C3))) && (C3->getValue() & ~C1->getValue()) == 0 && match(B, m_Or(m_Specific(V1), m_ConstantInt(C4))) && (C4->getValue() & ~C2->getValue()) == 0) { V2 = Builder->CreateOr(V1, ConstantExpr::getOr(C3, C4), "bitfield"); return BinaryOperator::CreateAnd(V2, - ConstantInt::get(B->getContext(), - C1->getValue()|C2->getValue())); + Builder->getInt(C1->getValue()|C2->getValue())); } } } - - // Check to see if we have any common things being and'ed. If so, find the - // terms for V1 & (V2|V3). - if (Op0->hasOneUse() || Op1->hasOneUse()) { - V1 = 0; - if (A == B) // (A & C)|(A & D) == A & (C|D) - V1 = A, V2 = C, V3 = D; - else if (A == D) // (A & C)|(B & A) == A & (B|C) - V1 = A, V2 = B, V3 = C; - else if (C == B) // (A & C)|(C & D) == C & (A|D) - V1 = C, V2 = A, V3 = D; - else if (C == D) // (A & C)|(B & C) == C & (A|B) - V1 = C, V2 = A, V3 = B; - - if (V1) { - Value *Or = Builder->CreateOr(V2, V3, "tmp"); - return BinaryOperator::CreateAnd(V1, Or); - } - } // (A & (C0?-1:0)) | (B & ~(C0?-1:0)) -> C0 ? A : B, and commuted variants. // Don't do this for vector select idioms, the code generator doesn't handle @@ -1636,16 +2092,16 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { if (Ret) return Ret; } } - + // (X >> Z) | (Y >> Z) -> (X|Y) >> Z for all shifts. if (BinaryOperator *SI1 = dyn_cast(Op1)) { if (BinaryOperator *SI0 = dyn_cast(Op0)) - if (SI0->isShift() && SI0->getOpcode() == SI1->getOpcode() && + if (SI0->isShift() && SI0->getOpcode() == SI1->getOpcode() && SI0->getOperand(1) == SI1->getOperand(1) && (SI0->hasOneUse() || SI1->hasOneUse())) { Value *NewOp = Builder->CreateOr(SI0->getOperand(0), SI1->getOperand(0), SI0->getName()); - return BinaryOperator::Create(SI1->getOpcode(), NewOp, + return BinaryOperator::Create(SI1->getOpcode(), NewOp, SI1->getOperand(1)); } } @@ -1659,83 +2115,155 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { return BinaryOperator::CreateNot(And); } + // Canonicalize xor to the RHS. + bool SwappedForXor = false; + if (match(Op0, m_Xor(m_Value(), m_Value()))) { + std::swap(Op0, Op1); + SwappedForXor = true; + } + + // A | ( A ^ B) -> A | B + // A | (~A ^ B) -> A | ~B + // (A & B) | (A ^ B) + if (match(Op1, m_Xor(m_Value(A), m_Value(B)))) { + if (Op0 == A || Op0 == B) + return BinaryOperator::CreateOr(A, B); + + if (match(Op0, m_And(m_Specific(A), m_Specific(B))) || + match(Op0, m_And(m_Specific(B), m_Specific(A)))) + return BinaryOperator::CreateOr(A, B); + + if (Op1->hasOneUse() && match(A, m_Not(m_Specific(Op0)))) { + Value *Not = Builder->CreateNot(B, B->getName()+".not"); + return BinaryOperator::CreateOr(Not, Op0); + } + if (Op1->hasOneUse() && match(B, m_Not(m_Specific(Op0)))) { + Value *Not = Builder->CreateNot(A, A->getName()+".not"); + return BinaryOperator::CreateOr(Not, Op0); + } + } + + // A | ~(A | B) -> A | ~B + // A | ~(A ^ B) -> A | ~B + if (match(Op1, m_Not(m_Value(A)))) + if (BinaryOperator *B = dyn_cast(A)) + if ((Op0 == B->getOperand(0) || Op0 == B->getOperand(1)) && + Op1->hasOneUse() && (B->getOpcode() == Instruction::Or || + B->getOpcode() == Instruction::Xor)) { + Value *NotOp = Op0 == B->getOperand(0) ? B->getOperand(1) : + B->getOperand(0); + Value *Not = Builder->CreateNot(NotOp, NotOp->getName()+".not"); + return BinaryOperator::CreateOr(Not, Op0); + } + + if (SwappedForXor) + std::swap(Op0, Op1); + if (ICmpInst *RHS = dyn_cast(I.getOperand(1))) if (ICmpInst *LHS = dyn_cast(I.getOperand(0))) if (Value *Res = FoldOrOfICmps(LHS, RHS)) return ReplaceInstUsesWith(I, Res); - + // (fcmp uno x, c) | (fcmp uno y, c) -> (fcmp uno x, y) if (FCmpInst *LHS = dyn_cast(I.getOperand(0))) if (FCmpInst *RHS = dyn_cast(I.getOperand(1))) if (Value *Res = FoldOrOfFCmps(LHS, RHS)) return ReplaceInstUsesWith(I, Res); - + // fold (or (cast A), (cast B)) -> (cast (or A, B)) if (CastInst *Op0C = dyn_cast(Op0)) { - if (CastInst *Op1C = dyn_cast(Op1)) - if (Op0C->getOpcode() == Op1C->getOpcode()) {// same cast kind ? - const Type *SrcTy = Op0C->getOperand(0)->getType(); - if (SrcTy == Op1C->getOperand(0)->getType() && - SrcTy->isIntOrIntVectorTy()) { - Value *Op0COp = Op0C->getOperand(0), *Op1COp = Op1C->getOperand(0); - - if ((!isa(Op0COp) || !isa(Op1COp)) && - // Only do this if the casts both really cause code to be - // generated. - ShouldOptimizeCast(Op0C->getOpcode(), Op0COp, I.getType()) && - ShouldOptimizeCast(Op1C->getOpcode(), Op1COp, I.getType())) { - Value *NewOp = Builder->CreateOr(Op0COp, Op1COp, I.getName()); - return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType()); - } - - // If this is or(cast(icmp), cast(icmp)), try to fold this even if the - // cast is otherwise not optimizable. This happens for vector sexts. - if (ICmpInst *RHS = dyn_cast(Op1COp)) - if (ICmpInst *LHS = dyn_cast(Op0COp)) - if (Value *Res = FoldOrOfICmps(LHS, RHS)) - return CastInst::Create(Op0C->getOpcode(), Res, I.getType()); - - // If this is or(cast(fcmp), cast(fcmp)), try to fold this even if the - // cast is otherwise not optimizable. This happens for vector sexts. - if (FCmpInst *RHS = dyn_cast(Op1COp)) - if (FCmpInst *LHS = dyn_cast(Op0COp)) - if (Value *Res = FoldOrOfFCmps(LHS, RHS)) - return CastInst::Create(Op0C->getOpcode(), Res, I.getType()); + CastInst *Op1C = dyn_cast(Op1); + if (Op1C && Op0C->getOpcode() == Op1C->getOpcode()) {// same cast kind ? + Type *SrcTy = Op0C->getOperand(0)->getType(); + if (SrcTy == Op1C->getOperand(0)->getType() && + SrcTy->isIntOrIntVectorTy()) { + Value *Op0COp = Op0C->getOperand(0), *Op1COp = Op1C->getOperand(0); + + if ((!isa(Op0COp) || !isa(Op1COp)) && + // Only do this if the casts both really cause code to be + // generated. + ShouldOptimizeCast(Op0C->getOpcode(), Op0COp, I.getType()) && + ShouldOptimizeCast(Op1C->getOpcode(), Op1COp, I.getType())) { + Value *NewOp = Builder->CreateOr(Op0COp, Op1COp, I.getName()); + return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType()); } + + // If this is or(cast(icmp), cast(icmp)), try to fold this even if the + // cast is otherwise not optimizable. This happens for vector sexts. + if (ICmpInst *RHS = dyn_cast(Op1COp)) + if (ICmpInst *LHS = dyn_cast(Op0COp)) + if (Value *Res = FoldOrOfICmps(LHS, RHS)) + return CastInst::Create(Op0C->getOpcode(), Res, I.getType()); + + // If this is or(cast(fcmp), cast(fcmp)), try to fold this even if the + // cast is otherwise not optimizable. This happens for vector sexts. + if (FCmpInst *RHS = dyn_cast(Op1COp)) + if (FCmpInst *LHS = dyn_cast(Op0COp)) + if (Value *Res = FoldOrOfFCmps(LHS, RHS)) + return CastInst::Create(Op0C->getOpcode(), Res, I.getType()); } + } } - - return Changed ? &I : 0; + + // or(sext(A), B) -> A ? -1 : B where A is an i1 + // or(A, sext(B)) -> B ? -1 : A where B is an i1 + if (match(Op0, m_SExt(m_Value(A))) && A->getType()->isIntegerTy(1)) + return SelectInst::Create(A, ConstantInt::getSigned(I.getType(), -1), Op1); + if (match(Op1, m_SExt(m_Value(A))) && A->getType()->isIntegerTy(1)) + return SelectInst::Create(A, ConstantInt::getSigned(I.getType(), -1), Op0); + + // Note: If we've gotten to the point of visiting the outer OR, then the + // inner one couldn't be simplified. If it was a constant, then it won't + // be simplified by a later pass either, so we try swapping the inner/outer + // ORs in the hopes that we'll be able to simplify it this way. + // (X|C) | V --> (X|V) | C + if (Op0->hasOneUse() && !isa(Op1) && + match(Op0, m_Or(m_Value(A), m_ConstantInt(C1)))) { + Value *Inner = Builder->CreateOr(A, Op1); + Inner->takeName(Op0); + return BinaryOperator::CreateOr(Inner, C1); + } + + // Change (or (bool?A:B),(bool?C:D)) --> (bool?(or A,C):(or B,D)) + // Since this OR statement hasn't been optimized further yet, we hope + // that this transformation will allow the new ORs to be optimized. + { + Value *X = nullptr, *Y = nullptr; + if (Op0->hasOneUse() && Op1->hasOneUse() && + match(Op0, m_Select(m_Value(X), m_Value(A), m_Value(B))) && + match(Op1, m_Select(m_Value(Y), m_Value(C), m_Value(D))) && X == Y) { + Value *orTrue = Builder->CreateOr(A, C); + Value *orFalse = Builder->CreateOr(B, D); + return SelectInst::Create(X, orTrue, orFalse); + } + } + + return Changed ? &I : nullptr; } Instruction *InstCombiner::visitXor(BinaryOperator &I) { - bool Changed = SimplifyCommutative(I); + bool Changed = SimplifyAssociativeOrCommutative(I); Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1); - if (isa(Op1)) { - if (isa(Op0)) - // Handle undef ^ undef -> 0 special case. This is a common - // idiom (misuse). - return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType())); - return ReplaceInstUsesWith(I, Op1); // X ^ undef -> undef - } + if (Value *V = SimplifyVectorOp(I)) + return ReplaceInstUsesWith(I, V); - // xor X, X = 0 - if (Op0 == Op1) - return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType())); - - // See if we can simplify any instructions used by the instruction whose sole + if (Value *V = SimplifyXorInst(Op0, Op1, DL)) + return ReplaceInstUsesWith(I, V); + + // (A&B)^(A&C) -> A&(B^C) etc + if (Value *V = SimplifyUsingDistributiveLaws(I)) + return ReplaceInstUsesWith(I, V); + + // See if we can simplify any instructions used by the instruction whose sole // purpose is to compute bits we don't care about. if (SimplifyDemandedInstructionBits(I)) return &I; - if (I.getType()->isVectorTy()) - if (isa(Op1)) - return ReplaceInstUsesWith(I, Op0); // X ^ <0,0> -> X // Is this a ~ operation? if (Value *NotOp = dyn_castNotVal(&I)) { if (BinaryOperator *Op0I = dyn_cast(NotOp)) { - if (Op0I->getOpcode() == Instruction::And || + if (Op0I->getOpcode() == Instruction::And || Op0I->getOpcode() == Instruction::Or) { // ~(~X & Y) --> (X | ~Y) - De Morgan's Law // ~(~X | Y) === (X & ~Y) - De Morgan's Law @@ -1749,10 +2277,10 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) { return BinaryOperator::CreateOr(Op0NotVal, NotY); return BinaryOperator::CreateAnd(Op0NotVal, NotY); } - + // ~(X & Y) --> (~X | ~Y) - De Morgan's Law // ~(X | Y) === (~X & ~Y) - De Morgan's Law - if (isFreeToInvert(Op0I->getOperand(0)) && + if (isFreeToInvert(Op0I->getOperand(0)) && isFreeToInvert(Op0I->getOperand(1))) { Value *NotX = Builder->CreateNot(Op0I->getOperand(0), "notlhs"); @@ -1770,8 +2298,8 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) { } } } - - + + if (ConstantInt *RHS = dyn_cast(Op1)) { if (RHS->isOne() && Op0->hasOneUse()) // xor (cmp A, B), true = not (cmp A, B) = !cmp A, B @@ -1786,8 +2314,7 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) { if (CI->hasOneUse() && Op0C->hasOneUse()) { Instruction::CastOps Opcode = Op0C->getOpcode(); if ((Opcode == Instruction::ZExt || Opcode == Instruction::SExt) && - (RHS == ConstantExpr::getCast(Opcode, - ConstantInt::getTrue(I.getContext()), + (RHS == ConstantExpr::getCast(Opcode, Builder->getTrue(), Op0C->getDestTy()))) { CI->setPredicate(CI->getInversePredicate()); return CastInst::Create(Opcode, CI, Op0C->getType()); @@ -1805,7 +2332,7 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) { ConstantInt::get(I.getType(), 1)); return BinaryOperator::CreateAdd(Op0I->getOperand(1), ConstantRHS); } - + if (ConstantInt *Op0CI = dyn_cast(Op0I->getOperand(1))) { if (Op0I->getOpcode() == Instruction::Add) { // ~(X-c) --> (-c-1)-X @@ -1817,8 +2344,7 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) { Op0I->getOperand(0)); } else if (RHS->getValue().isSignBit()) { // (X + C) ^ signbit -> (X + C + signbit) - Constant *C = ConstantInt::get(I.getContext(), - RHS->getValue() + Op0CI->getValue()); + Constant *C = Builder->getInt(RHS->getValue() + Op0CI->getValue()); return BinaryOperator::CreateAdd(Op0I->getOperand(0), C); } @@ -1829,13 +2355,34 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) { // Anything in both C1 and C2 is known to be zero, remove it from // NewRHS. Constant *CommonBits = ConstantExpr::getAnd(Op0CI, RHS); - NewRHS = ConstantExpr::getAnd(NewRHS, + NewRHS = ConstantExpr::getAnd(NewRHS, ConstantExpr::getNot(CommonBits)); Worklist.Add(Op0I); I.setOperand(0, Op0I->getOperand(0)); I.setOperand(1, NewRHS); return &I; } + } else if (Op0I->getOpcode() == Instruction::LShr) { + // ((X^C1) >> C2) ^ C3 -> (X>>C2) ^ ((C1>>C2)^C3) + // E1 = "X ^ C1" + BinaryOperator *E1; + ConstantInt *C1; + if (Op0I->hasOneUse() && + (E1 = dyn_cast(Op0I->getOperand(0))) && + E1->getOpcode() == Instruction::Xor && + (C1 = dyn_cast(E1->getOperand(1)))) { + // fold (C1 >> C2) ^ C3 + ConstantInt *C2 = Op0CI, *C3 = RHS; + APInt FoldConst = C1->getValue().lshr(C2->getValue()); + FoldConst ^= C3->getValue(); + // Prepare the two operands. + Value *Opnd0 = Builder->CreateLShr(E1->getOperand(0), C2); + Opnd0->takeName(Op0I); + cast(Opnd0)->setDebugLoc(I.getDebugLoc()); + Value *FoldVal = ConstantInt::get(Opnd0->getType(), FoldConst); + + return BinaryOperator::CreateXor(Opnd0, FoldVal); + } } } } @@ -1849,15 +2396,6 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) { return NV; } - if (Value *X = dyn_castNotVal(Op0)) // ~A ^ A == -1 - if (X == Op1) - return ReplaceInstUsesWith(I, Constant::getAllOnesValue(I.getType())); - - if (Value *X = dyn_castNotVal(Op1)) // A ^ ~A == -1 - if (X == Op0) - return ReplaceInstUsesWith(I, Constant::getAllOnesValue(I.getType())); - - BinaryOperator *Op1I = dyn_cast(Op1); if (Op1I) { Value *A, *B; @@ -1870,11 +2408,7 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) { I.swapOperands(); // Simplified below. std::swap(Op0, Op1); } - } else if (match(Op1I, m_Xor(m_Specific(Op0), m_Value(B)))) { - return ReplaceInstUsesWith(I, B); // A^(A^B) == B - } else if (match(Op1I, m_Xor(m_Value(A), m_Specific(Op0)))) { - return ReplaceInstUsesWith(I, A); // A^(B^A) == B - } else if (match(Op1I, m_And(m_Value(A), m_Value(B))) && + } else if (match(Op1I, m_And(m_Value(A), m_Value(B))) && Op1I->hasOneUse()){ if (A == Op0) { // A^(A&B) -> A^(B&A) Op1I->swapOperands(); @@ -1886,7 +2420,7 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) { } } } - + BinaryOperator *Op0I = dyn_cast(Op0); if (Op0I) { Value *A, *B; @@ -1895,71 +2429,46 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) { if (A == Op1) // (B|A)^B == (A|B)^B std::swap(A, B); if (B == Op1) // (A|B)^B == A & ~B - return BinaryOperator::CreateAnd(A, Builder->CreateNot(Op1, "tmp")); - } else if (match(Op0I, m_Xor(m_Specific(Op1), m_Value(B)))) { - return ReplaceInstUsesWith(I, B); // (A^B)^A == B - } else if (match(Op0I, m_Xor(m_Value(A), m_Specific(Op1)))) { - return ReplaceInstUsesWith(I, A); // (B^A)^A == B - } else if (match(Op0I, m_And(m_Value(A), m_Value(B))) && + return BinaryOperator::CreateAnd(A, Builder->CreateNot(Op1)); + } else if (match(Op0I, m_And(m_Value(A), m_Value(B))) && Op0I->hasOneUse()){ if (A == Op1) // (A&B)^A -> (B&A)^A std::swap(A, B); if (B == Op1 && // (B&A)^A == ~B & A !isa(Op1)) { // Canonical form is (B&C)^C - return BinaryOperator::CreateAnd(Builder->CreateNot(A, "tmp"), Op1); + return BinaryOperator::CreateAnd(Builder->CreateNot(A), Op1); } } } - + // (X >> Z) ^ (Y >> Z) -> (X^Y) >> Z for all shifts. - if (Op0I && Op1I && Op0I->isShift() && - Op0I->getOpcode() == Op1I->getOpcode() && + if (Op0I && Op1I && Op0I->isShift() && + Op0I->getOpcode() == Op1I->getOpcode() && Op0I->getOperand(1) == Op1I->getOperand(1) && - (Op1I->hasOneUse() || Op1I->hasOneUse())) { + (Op0I->hasOneUse() || Op1I->hasOneUse())) { Value *NewOp = Builder->CreateXor(Op0I->getOperand(0), Op1I->getOperand(0), Op0I->getName()); - return BinaryOperator::Create(Op1I->getOpcode(), NewOp, + return BinaryOperator::Create(Op1I->getOpcode(), NewOp, Op1I->getOperand(1)); } - + if (Op0I && Op1I) { Value *A, *B, *C, *D; // (A & B)^(A | B) -> A ^ B if (match(Op0I, m_And(m_Value(A), m_Value(B))) && match(Op1I, m_Or(m_Value(C), m_Value(D)))) { - if ((A == C && B == D) || (A == D && B == C)) + if ((A == C && B == D) || (A == D && B == C)) return BinaryOperator::CreateXor(A, B); } // (A | B)^(A & B) -> A ^ B if (match(Op0I, m_Or(m_Value(A), m_Value(B))) && match(Op1I, m_And(m_Value(C), m_Value(D)))) { - if ((A == C && B == D) || (A == D && B == C)) + if ((A == C && B == D) || (A == D && B == C)) return BinaryOperator::CreateXor(A, B); } - - // (A & B)^(C & D) - if ((Op0I->hasOneUse() || Op1I->hasOneUse()) && - match(Op0I, m_And(m_Value(A), m_Value(B))) && - match(Op1I, m_And(m_Value(C), m_Value(D)))) { - // (X & Y)^(X & Y) -> (Y^Z) & X - Value *X = 0, *Y = 0, *Z = 0; - if (A == C) - X = A, Y = B, Z = D; - else if (A == D) - X = A, Y = B, Z = C; - else if (B == C) - X = B, Y = A, Z = D; - else if (B == D) - X = B, Y = A, Z = C; - - if (X) { - Value *NewOp = Builder->CreateXor(Y, Z, Op0->getName()); - return BinaryOperator::CreateAnd(NewOp, X); - } - } } - + // (icmp1 A, B) ^ (icmp2 A, B) --> (icmp3 A, B) if (ICmpInst *RHS = dyn_cast(I.getOperand(1))) if (ICmpInst *LHS = dyn_cast(I.getOperand(0))) @@ -1972,8 +2481,9 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) { Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1); unsigned Code = getICmpCode(LHS) ^ getICmpCode(RHS); bool isSigned = LHS->isSigned() || RHS->isSigned(); - return ReplaceInstUsesWith(I, - getICmpValue(isSigned, Code, Op0, Op1, Builder)); + return ReplaceInstUsesWith(I, + getNewICmpValue(isSigned, Code, Op0, Op1, + Builder)); } } @@ -1981,12 +2491,12 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) { if (CastInst *Op0C = dyn_cast(Op0)) { if (CastInst *Op1C = dyn_cast(Op1)) if (Op0C->getOpcode() == Op1C->getOpcode()) { // same cast kind? - const Type *SrcTy = Op0C->getOperand(0)->getType(); + Type *SrcTy = Op0C->getOperand(0)->getType(); if (SrcTy == Op1C->getOperand(0)->getType() && SrcTy->isIntegerTy() && // Only do this if the casts both really cause code to be generated. - ShouldOptimizeCast(Op0C->getOpcode(), Op0C->getOperand(0), + ShouldOptimizeCast(Op0C->getOpcode(), Op0C->getOperand(0), I.getType()) && - ShouldOptimizeCast(Op1C->getOpcode(), Op1C->getOperand(0), + ShouldOptimizeCast(Op1C->getOpcode(), Op1C->getOperand(0), I.getType())) { Value *NewOp = Builder->CreateXor(Op0C->getOperand(0), Op1C->getOperand(0), I.getName()); @@ -1995,5 +2505,5 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) { } } - return Changed ? &I : 0; + return Changed ? &I : nullptr; }