[PATCH] D144319: [SimplifyCFG] Check if the return instruction causes undefined behavior

[Mark de Wever via Phabricator via llvm-commits]

Mordante added a comment.

In D144319#4204004 <https://reviews.llvm.org/D144319#4204004>, @DianQK wrote:

>> Would it be possible to fix this issue quickly, if not can you revert this patch?
>
> As @xbolva00 mentioned, if you're sure your code doesn't have UB, you can revert my commit first.
> Can you provide libc++ related commits? Only 564ed0b <https://github.com/llvm-premerge-tests/llvm-project/commit/564ed0bd2245d4477dfd1c2f610294eff697edab>?
> I can investigate tomorrow when I wake up.

Tomorrow is fine by me.

Here is one of the test files failing. This only fails when exceptions are disabled in libc++ and libc++-abi.

libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow.pass.cpp

I don't directly see anything undefined behaviour. Note in the failures the `asserts` are not triggered so if
allocating the large amount of memory would succeed there would a message in the CI log.


Repository:
  rG LLVM Github Monorepo

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https://reviews.llvm.org/D144319