[libcxx-commits] [libcxx] [libc++] Don't assume alignment of empty ranges (PR #213752)

[Louis Dionne via libcxx-commits]

ldionne wrote:

> I meant returning false for `__is_valid_range` if the pointers aren't properly aligned.

I see, but the result would be the same as what we have right now, i.e. we would still reject funky sentinels that are not aligned.

At the moment the next step is to figure out why our benchmarks [don't currently show a difference](https://github.com/llvm/llvm-project/pull/213752#issuecomment-5217735628) when removing the assumption entirely (which should prevent the compiler from vectorizing IIUC).

https://github.com/llvm/llvm-project/pull/213752