https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120895
--- Comment #34 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to David C. Partridge from comment #32) > It is totally WRONG to set different alignments for this data type depending > on compiler options I think the point is that it's not the same data type. __m512 means something different depending on the compiler options. It's a different type, with different alignment, it just has the same name. > If you generate code to align this differently for cpp files compiled with > different options, then when these files are linked they won't agree on the > alignment. And they don't agree on the type either, so they're already wrong, and you should not be doing that.