diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index c8e0b332215..e183b505bfb 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -3540,24 +3540,29 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { } break; } - case ICmpInst::ICMP_ULT: + case ICmpInst::ICMP_ULT: { if (Op0Max.ult(Op1Min)) // A <u B -> true if max(A) < min(B) return replaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); if (Op0Min.uge(Op1Max)) // A <u B -> false if min(A) >= max(B) return replaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); if (Op1Min == Op0Max) // A <u B -> A != B if max(A) == min(B) return new ICmpInst(ICmpInst::ICMP_NE, Op0, Op1); - if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) { - if (Op1Max == Op0Min+1) // A <u C -> A == C-1 if min(A)+1 == C - return new ICmpInst(ICmpInst::ICMP_EQ, Op0, - Builder->getInt(CI->getValue()-1)); + const APInt *CmpC; + if (match(Op1, m_APInt(CmpC))) { + // A <u C -> A == C-1 if min(A)+1 == C + if (Op1Max == Op0Min + 1) { + Constant *CMinus1 = ConstantInt::get(Op0->getType(), *CmpC - 1); + return new ICmpInst(ICmpInst::ICMP_EQ, Op0, CMinus1); + } // (x <u 2147483648) -> (x >s -1) -> true if sign bit clear - if (CI->isMinValue(true)) - return new ICmpInst(ICmpInst::ICMP_SGT, Op0, - Constant::getAllOnesValue(Op0->getType())); + if (CmpC->isMinSignedValue()) { + Constant *AllOnes = Constant::getAllOnesValue(Op0->getType()); + return new ICmpInst(ICmpInst::ICMP_SGT, Op0, AllOnes); + } } break; + } case ICmpInst::ICMP_UGT: { if (Op0Min.ugt(Op1Max)) // A >u B -> true if min(A) > max(B) return replaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); |
