diff options
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index efeb8344b9..672fe852e6 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -5593,7 +5593,28 @@ Instruction *InstCombiner::visitICmpInstWithCastAndCast(ICmpInst &ICI) { const Type *DestTy = LHSCI->getType(); Value *RHSCIOp; - // We only handle extension cast instructions, so far. Enforce this. + // Turn icmp (ptrtoint x), (ptrtoint/c) into a compare of the input if the + // integer type is the same size as the pointer type. + if (LHSCI->getOpcode() == Instruction::PtrToInt && + getTargetData().getPointerSizeInBits() == + cast<IntegerType>(DestTy)->getBitWidth()) { + Value *RHSOp = 0; + if (Constant *RHSC = dyn_cast<Constant>(ICI.getOperand(1))) { + RHSOp = ConstantExpr::getPtrToInt(RHSC, SrcTy); + } else if (PtrToIntInst *RHSC = dyn_cast<PtrToIntInst>(ICI.getOperand(1))) { + RHSOp = RHSC->getOperand(0); + // If the pointer types don't match, insert a bitcast. + if (LHSCIOp->getType() != RHSOp->getType()) + RHSOp = InsertCastBefore(Instruction::BitCast, RHSOp, + LHSCIOp->getType(), ICI); + } + + if (RHSOp) + return new ICmpInst(ICI.getPredicate(), LHSCIOp, RHSOp); + } + + // The code below only handles extension cast instructions, so far. + // Enforce this. if (LHSCI->getOpcode() != Instruction::ZExt && LHSCI->getOpcode() != Instruction::SExt) return 0; |