diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | 43 |
1 files changed, 28 insertions, 15 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index a8f2cd79830a..8253c575bc37 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -2664,8 +2664,8 @@ Value *InstCombinerImpl::foldAndOrOfICmps(ICmpInst *LHS, ICmpInst *RHS, // Inverted form (example): // (icmp slt (X | Y), 0) & (icmp sgt (X & Y), -1) -> (icmp slt (X ^ Y), 0) bool TrueIfSignedL, TrueIfSignedR; - if (InstCombiner::isSignBitCheck(PredL, *LHSC, TrueIfSignedL) && - InstCombiner::isSignBitCheck(PredR, *RHSC, TrueIfSignedR) && + if (isSignBitCheck(PredL, *LHSC, TrueIfSignedL) && + isSignBitCheck(PredR, *RHSC, TrueIfSignedR) && (RHS->hasOneUse() || LHS->hasOneUse())) { Value *X, *Y; if (IsAnd) { @@ -3202,25 +3202,38 @@ Value *InstCombinerImpl::foldXorOfICmps(ICmpInst *LHS, ICmpInst *RHS, // TODO: This can be generalized to compares of non-signbits using // decomposeBitTestICmp(). It could be enhanced more by using (something like) // foldLogOpOfMaskedICmps(). - if ((LHS->hasOneUse() || RHS->hasOneUse()) && + const APInt *LC, *RC; + if (match(LHS1, m_APInt(LC)) && match(RHS1, m_APInt(RC)) && LHS0->getType() == RHS0->getType() && - LHS0->getType()->isIntOrIntVectorTy()) { + LHS0->getType()->isIntOrIntVectorTy() && + (LHS->hasOneUse() || RHS->hasOneUse())) { + // Convert xor of signbit tests to signbit test of xor'd values: // (X > -1) ^ (Y > -1) --> (X ^ Y) < 0 // (X < 0) ^ (Y < 0) --> (X ^ Y) < 0 - if ((PredL == CmpInst::ICMP_SGT && match(LHS1, m_AllOnes()) && - PredR == CmpInst::ICMP_SGT && match(RHS1, m_AllOnes())) || - (PredL == CmpInst::ICMP_SLT && match(LHS1, m_Zero()) && - PredR == CmpInst::ICMP_SLT && match(RHS1, m_Zero()))) - return Builder.CreateIsNeg(Builder.CreateXor(LHS0, RHS0)); - // (X > -1) ^ (Y < 0) --> (X ^ Y) > -1 // (X < 0) ^ (Y > -1) --> (X ^ Y) > -1 - if ((PredL == CmpInst::ICMP_SGT && match(LHS1, m_AllOnes()) && - PredR == CmpInst::ICMP_SLT && match(RHS1, m_Zero())) || - (PredL == CmpInst::ICMP_SLT && match(LHS1, m_Zero()) && - PredR == CmpInst::ICMP_SGT && match(RHS1, m_AllOnes()))) - return Builder.CreateIsNotNeg(Builder.CreateXor(LHS0, RHS0)); + bool TrueIfSignedL, TrueIfSignedR; + if (isSignBitCheck(PredL, *LC, TrueIfSignedL) && + isSignBitCheck(PredR, *RC, TrueIfSignedR)) { + Value *XorLR = Builder.CreateXor(LHS0, RHS0); + return TrueIfSignedL == TrueIfSignedR ? Builder.CreateIsNeg(XorLR) : + Builder.CreateIsNotNeg(XorLR); + } + // (X > C) ^ (X < C + 2) --> X != C + 1 + // (X < C + 2) ^ (X > C) --> X != C + 1 + // Considering the correctness of this pattern, we should avoid that C is + // non-negative and C + 2 is negative, although it will be matched by other + // patterns. + const APInt *C1, *C2; + if ((PredL == CmpInst::ICMP_SGT && match(LHS1, m_APInt(C1)) && + PredR == CmpInst::ICMP_SLT && match(RHS1, m_APInt(C2))) || + (PredL == CmpInst::ICMP_SLT && match(LHS1, m_APInt(C2)) && + PredR == CmpInst::ICMP_SGT && match(RHS1, m_APInt(C1)))) + if (LHS0 == RHS0 && *C1 + 2 == *C2 && + (C1->isNegative() || C2->isNonNegative())) + return Builder.CreateICmpNE(LHS0, + ConstantInt::get(LHS0->getType(), *C1 + 1)); } // Instead of trying to imitate the folds for and/or, decompose this 'xor' |