diff options
Diffstat (limited to 'lib/Transforms/InstCombine/InstCombineCompares.cpp')
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineCompares.cpp | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp index ab2987f..7076d88 100644 --- a/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -1035,7 +1035,7 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, if ((KnownZero|KnownOne).countLeadingOnes() >= SrcBits-DstBits) { // Pull in the high bits from known-ones set. APInt NewRHS = RHS->getValue().zext(SrcBits); - NewRHS |= KnownOne; + NewRHS |= KnownOne & APInt::getHighBitsSet(SrcBits, SrcBits-DstBits); return new ICmpInst(ICI.getPredicate(), LHSI->getOperand(0), ConstantInt::get(ICI.getContext(), NewRHS)); } @@ -2580,10 +2580,25 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { } } + // Transform (zext A) == (B & (1<<X)-1) --> A == (trunc B) + // and (B & (1<<X)-1) == (zext A) --> A == (trunc B) + ConstantInt *Cst1; + if ((Op0->hasOneUse() && + match(Op0, m_ZExt(m_Value(A))) && + match(Op1, m_And(m_Value(B), m_ConstantInt(Cst1)))) || + (Op1->hasOneUse() && + match(Op0, m_And(m_Value(B), m_ConstantInt(Cst1))) && + match(Op1, m_ZExt(m_Value(A))))) { + APInt Pow2 = Cst1->getValue() + 1; + if (Pow2.isPowerOf2() && isa<IntegerType>(A->getType()) && + Pow2.logBase2() == cast<IntegerType>(A->getType())->getBitWidth()) + return new ICmpInst(I.getPredicate(), A, + Builder->CreateTrunc(B, A->getType())); + } + // Transform "icmp eq (trunc (lshr(X, cst1)), cst" to // "icmp (and X, mask), cst" uint64_t ShAmt = 0; - ConstantInt *Cst1; if (Op0->hasOneUse() && match(Op0, m_Trunc(m_OneUse(m_LShr(m_Value(A), m_ConstantInt(ShAmt))))) && |