http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48377
--- Comment #32 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-04-07 13:43:47 UTC --- Given that without vectorization that code surely works well on all the weird ABIs, such ADJUST_FIELD_ALIGN is used only on targets that either aren't strict alignment targets, or aren't strict alignment targets for the particular types. You know, for most CPUs strict alignment isn't a binary thing, many targets including i?86/x86_64 are only partially strict alignment targets. Even for targets where say int needs to be accessed aligned often e.g. double can be just 4 byte aligned and insns that read/write doubles handle it. We really shouldn't change __alignof__ of types/INDIRECT_REFs/etc., those are all ABI changes. The problem with vectorization is that often the vectors have strict alignment, while non-vector ops are not.
