[Bug target/111107] i686-w64-mingw32 does not realign stack when __attribute__((aligned)) or __attribute__((vector_size)) are used

[ebotcazou at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111107

--- Comment #44 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> Right, sorry, I should clarify—I can see what the *actual* effect of
> -mstackrealign / __force_align_arg_pointer__ is. I'm confused at what its
> *intended* effect is. "Align to 16 bytes, but only if we need 16-byte
> alignment, and do nothing if we need 8-byte alignment" seems very odd and
> not intended.

Yes, it was invented to support SSE instructions that require strict 16-byte
alignment of memory references.