diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/InstructionCombining.cpp | 29 |
1 files changed, 14 insertions, 15 deletions
diff --git a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp index eaab4c6b9c5..087d7d188dc 100644 --- a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp @@ -5133,25 +5133,22 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { return NI; // Test to see if the operands of the icmp are casted versions of other - // values. If the cast can be stripped off both arguments, we do so now. - if (CastInst *CI = dyn_cast<CastInst>(Op0)) { - Value *CastOp0 = CI->getOperand(0); - if (CI->isLosslessCast() && I.isEquality() && - (isa<Constant>(Op1) || isa<CastInst>(Op1))) { + // values. If the ptr->ptr cast can be stripped off both arguments, we do so + // now. + if (BitCastInst *CI = dyn_cast<BitCastInst>(Op0)) { + if (isa<PointerType>(Op0->getType()) && + (isa<Constant>(Op1) || isa<BitCastInst>(Op1))) { // We keep moving the cast from the left operand over to the right // operand, where it can often be eliminated completely. - Op0 = CastOp0; + Op0 = CI->getOperand(0); - // If operand #1 is a cast instruction, see if we can eliminate it as - // well. - if (CastInst *CI2 = dyn_cast<CastInst>(Op1)) { - Value *CI2Op0 = CI2->getOperand(0); - if (CI2Op0->getType()->canLosslesslyBitCastTo(Op0->getType())) - Op1 = CI2Op0; - } + // If operand #1 is a bitcast instruction, it must also be a ptr->ptr cast + // so eliminate it as well. + if (BitCastInst *CI2 = dyn_cast<BitCastInst>(Op1)) + Op1 = CI2->getOperand(0); // If Op1 is a constant, we can fold the cast into the constant. - if (Op1->getType() != Op0->getType()) + if (Op0->getType() != Op1->getType()) if (Constant *Op1C = dyn_cast<Constant>(Op1)) { Op1 = ConstantExpr::getBitCast(Op1C, Op0->getType()); } else { @@ -5160,7 +5157,9 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { } return new ICmpInst(I.getPredicate(), Op0, Op1); } - + } + + if (isa<CastInst>(Op0)) { // Handle the special case of: icmp (cast bool to X), <cst> // This comes up when you have code like // int X = A < B; |

