ChuanqiXu added a comment.
In D129833#3717291 <https://reviews.llvm.org/D129833#3717291>, @jyknight wrote:
> Note that this change caused LLVM to no longer be aware that a TLS variable
> cannot be NULL. Thus, code like:
>
> __thread int x;
> int main() {
> int* y = &x;
> return *y;
> }
>
> built with `clang -O -fsanitize=null` emits a null-pointer check, when it
> wouldn't previously. I think llvm.threadlocal.address's return value probably
> ought to be given the nonnull attribute. We also might want to infer other
> properties of the returned pointer based on knowledge of the global value
> parameter, such as alignment.
>
> Furthermore, while the above problem should simply be a very minor
> optimization degradation, in fact it caused miscompiles, due to a
> pre-existing bug in the X86 backend. I've sent
> https://reviews.llvm.org/D131716 to fix //that// part of the problem.
Oh, got it. I'll try to make it. And I find we can't set an intrinsic as
`NonNull` directly in Intrinsics.td and I filed an issue for it:
https://github.com/llvm/llvm-project/issues/57113.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D129833/new/
https://reviews.llvm.org/D129833
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