diff options
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 6b993750a3..27ba7ab163 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -2700,7 +2700,8 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { Value *Op = GEP.getOperand(i); if (Op->getType()->getPrimitiveSize() > TD->getPointerSize()) if (Constant *C = dyn_cast<Constant>(Op)) { - GEP.setOperand(i, ConstantExpr::getCast(C, TD->getIntPtrType())); + GEP.setOperand(i, ConstantExpr::getCast(C, + TD->getIntPtrType()->getSignedVersion())); MadeChange = true; } else { Op = InsertNewInstBefore(new CastInst(Op, TD->getIntPtrType(), @@ -2708,6 +2709,14 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { GEP.setOperand(i, Op); MadeChange = true; } + + // If this is a constant idx, make sure to canonicalize it to be a signed + // operand, otherwise CSE and other optimizations are pessimized. + if (ConstantUInt *CUI = dyn_cast<ConstantUInt>(Op)) { + GEP.setOperand(i, ConstantExpr::getCast(CUI, + CUI->getType()->getSignedVersion())); + MadeChange = true; + } } if (MadeChange) return &GEP; |