Change getelementptr folding to use APInt instead of uint64_t for
offset computations. This fixes a truncation bug on targets that
don't have 64-bit pointers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79639 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index 2dab8dd..19ea603 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -129,8 +129,9 @@
Constant *Ptr = Ops[0];
if (!TD || !cast<PointerType>(Ptr->getType())->getElementType()->isSized())
return 0;
-
- uint64_t BasePtr = 0;
+
+ unsigned BitWidth = TD->getTypeSizeInBits(TD->getIntPtrType(Context));
+ APInt BasePtr(BitWidth, 0);
bool BaseIsInt = true;
if (!Ptr->isNullValue()) {
// If this is a inttoptr from a constant int, we can fold this as the base,
@@ -138,7 +139,7 @@
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
if (CE->getOpcode() == Instruction::IntToPtr)
if (ConstantInt *Base = dyn_cast<ConstantInt>(CE->getOperand(0)))
- BasePtr = Base->getZExtValue();
+ BasePtr = Base->getValue();
if (BasePtr == 0)
BaseIsInt = false;
@@ -150,12 +151,13 @@
if (!isa<ConstantInt>(Ops[i]))
return 0;
- uint64_t Offset = TD->getIndexedOffset(Ptr->getType(),
- (Value**)Ops+1, NumOps-1);
+ APInt Offset = APInt(BitWidth,
+ TD->getIndexedOffset(Ptr->getType(),
+ (Value**)Ops+1, NumOps-1));
// If the base value for this address is a literal integer value, fold the
// getelementptr to the resulting integer value casted to the pointer type.
if (BaseIsInt) {
- Constant *C = ConstantInt::get(TD->getIntPtrType(Context), Offset+BasePtr);
+ Constant *C = ConstantInt::get(Context, Offset+BasePtr);
return ConstantExpr::getIntToPtr(C, ResultTy);
}
@@ -171,19 +173,21 @@
if (isa<PointerType>(ATy) && ATy != Ptr->getType())
break;
// Determine which element of the array the offset points into.
- uint64_t ElemSize = TD->getTypeAllocSize(ATy->getElementType());
+ APInt ElemSize(BitWidth, TD->getTypeAllocSize(ATy->getElementType()));
if (ElemSize == 0)
return 0;
- uint64_t NewIdx = Offset / ElemSize;
+ APInt NewIdx = Offset.udiv(ElemSize);
Offset -= NewIdx * ElemSize;
NewIdxs.push_back(ConstantInt::get(TD->getIntPtrType(Context), NewIdx));
Ty = ATy->getElementType();
} else if (const StructType *STy = dyn_cast<StructType>(Ty)) {
- // Determine which field of the struct the offset points into.
+ // Determine which field of the struct the offset points into. The
+ // getZExtValue is at least as safe as the StructLayout API because we
+ // know the offset is within the struct at this point.
const StructLayout &SL = *TD->getStructLayout(STy);
- unsigned ElIdx = SL.getElementContainingOffset(Offset);
+ unsigned ElIdx = SL.getElementContainingOffset(Offset.getZExtValue());
NewIdxs.push_back(ConstantInt::get(Type::getInt32Ty(Context), ElIdx));
- Offset -= SL.getElementOffset(ElIdx);
+ Offset -= APInt(BitWidth, SL.getElementOffset(ElIdx));
Ty = STy->getTypeAtIndex(ElIdx);
} else {
// We've reached some non-indexable type.