================
@@ -1497,6 +1497,21 @@ Constant *llvm::ConstantFoldCastOperand(unsigned Opcode,
Constant *C,
llvm_unreachable("Missing case");
case Instruction::PtrToAddr:
case Instruction::PtrToInt:
+ // If the input is a nullptr, we can fold it to the corresponding nullptr
+ // value.
+ if (Opcode == Instruction::PtrToInt && C->isNullValue()) {
+ if (std::optional<APInt> NullPtrValue = DL.getNullPtrValue(
+ C->getType()->getScalarType()->getPointerAddressSpace())) {
+ if (NullPtrValue->isZero()) {
+ return Constant::getZeroValue(DestTy);
+ } else if (NullPtrValue->isAllOnes()) {
+ return ConstantInt::get(
+ DestTy,
NullPtrValue->zextOrTrunc(DestTy->getScalarSizeInBits()));
+ } else {
+ llvm_unreachable("invalid nullptr value");
+ }
----------------
arichardson wrote:
```suggestion
assert(NullPtrValue->isZero() || NullPtrValue->isAllOnes());
return ConstantInt::get(
DestTy, NullPtrValue->zextOrTrunc(DestTy->getScalarSizeInBits()));
```
I believe this is equivalent and a bit simpler.
https://github.com/llvm/llvm-project/pull/166667
_______________________________________________
cfe-commits mailing list
[email protected]
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
