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Implement InstCombine/GEPIdxCanon.ll 

llvm-svn: 15024
This commit is contained in:
Chris Lattner 2004-07-20 01:48:15 +00:00
parent 9492af43c4
commit 44d0b9502a
1 changed files with 10 additions and 1 deletions
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11
llvm/lib/Transforms/Scalar/InstructionCombining.cpp
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@ -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;