Fix several latent bugs in EmitGEPOffset that didn't manifest with its

previous clients.  This fixes MallocBench/gs


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36525 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2007-04-28 04:52:43 +00:00
parent b017318122
commit e62f021c8c

View File

@ -4337,50 +4337,66 @@ static Value *EmitGEPOffset(User *GEP, Instruction &I, InstCombiner &IC) {
Value *Result = Constant::getNullValue(IntPtrTy);
// Build a mask for high order bits.
uint64_t PtrSizeMask = ~0ULL >> (64-TD.getPointerSize()*8);
unsigned IntPtrWidth = TD.getPointerSize()*8;
uint64_t PtrSizeMask = ~0ULL >> (64-IntPtrWidth);
for (unsigned i = 1, e = GEP->getNumOperands(); i != e; ++i, ++GTI) {
Value *Op = GEP->getOperand(i);
uint64_t Size = TD.getTypeSize(GTI.getIndexedType()) & PtrSizeMask;
Constant *Scale = ConstantInt::get(IntPtrTy, Size);
if (Constant *OpC = dyn_cast<Constant>(Op)) {
if (!OpC->isNullValue()) {
OpC = ConstantExpr::getIntegerCast(OpC, IntPtrTy, true /*SExt*/);
Scale = ConstantExpr::getMul(OpC, Scale);
if (Constant *RC = dyn_cast<Constant>(Result))
Result = ConstantExpr::getAdd(RC, Scale);
else {
// Emit an add instruction.
Result = IC.InsertNewInstBefore(
BinaryOperator::createAdd(Result, Scale,
GEP->getName()+".offs"), I);
}
}
} else {
// Convert to correct type.
if (Op->getType() != IntPtrTy) {
if (Constant *OpC = dyn_cast<Constant>(Op))
Op = ConstantExpr::getSExt(OpC, IntPtrTy);
if (ConstantInt *OpC = dyn_cast<ConstantInt>(Op)) {
if (OpC->isZero()) continue;
// Handle a struct index, which adds its field offset to the pointer.
if (const StructType *STy = dyn_cast<StructType>(*GTI)) {
Size = TD.getStructLayout(STy)->getElementOffset(OpC->getZExtValue());
if (ConstantInt *RC = dyn_cast<ConstantInt>(Result))
Result = ConstantInt::get(RC->getValue() + APInt(IntPtrWidth, Size));
else
Op = IC.InsertNewInstBefore(new SExtInst(Op, IntPtrTy,
Op->getName()+".c"), I);
Result = IC.InsertNewInstBefore(
BinaryOperator::createAdd(Result,
ConstantInt::get(IntPtrTy, Size),
GEP->getName()+".offs"), I);
continue;
}
if (Size != 1) {
if (Constant *OpC = dyn_cast<Constant>(Op))
Op = ConstantExpr::getMul(OpC, Scale);
else // We'll let instcombine(mul) convert this to a shl if possible.
Op = IC.InsertNewInstBefore(BinaryOperator::createMul(Op, Scale,
GEP->getName()+".idx"), I);
Constant *Scale = ConstantInt::get(IntPtrTy, Size);
Constant *OC = ConstantExpr::getIntegerCast(OpC, IntPtrTy, true /*SExt*/);
Scale = ConstantExpr::getMul(OC, Scale);
if (Constant *RC = dyn_cast<Constant>(Result))
Result = ConstantExpr::getAdd(RC, Scale);
else {
// Emit an add instruction.
Result = IC.InsertNewInstBefore(
BinaryOperator::createAdd(Result, Scale,
GEP->getName()+".offs"), I);
}
// Emit an add instruction.
if (isa<Constant>(Op) && isa<Constant>(Result))
Result = ConstantExpr::getAdd(cast<Constant>(Op),
cast<Constant>(Result));
else
Result = IC.InsertNewInstBefore(BinaryOperator::createAdd(Op, Result,
GEP->getName()+".offs"), I);
continue;
}
// Convert to correct type.
if (Op->getType() != IntPtrTy) {
if (Constant *OpC = dyn_cast<Constant>(Op))
Op = ConstantExpr::getSExt(OpC, IntPtrTy);
else
Op = IC.InsertNewInstBefore(new SExtInst(Op, IntPtrTy,
Op->getName()+".c"), I);
}
if (Size != 1) {
Constant *Scale = ConstantInt::get(IntPtrTy, Size);
if (Constant *OpC = dyn_cast<Constant>(Op))
Op = ConstantExpr::getMul(OpC, Scale);
else // We'll let instcombine(mul) convert this to a shl if possible.
Op = IC.InsertNewInstBefore(BinaryOperator::createMul(Op, Scale,
GEP->getName()+".idx"), I);
}
// Emit an add instruction.
if (isa<Constant>(Op) && isa<Constant>(Result))
Result = ConstantExpr::getAdd(cast<Constant>(Op),
cast<Constant>(Result));
else
Result = IC.InsertNewInstBefore(BinaryOperator::createAdd(Op, Result,
GEP->getName()+".offs"), I);
}
return Result;
}