------- Comment #4 from hjl dot tools at gmail dot com 2010-07-15 13:33 ------- (In reply to comment #2) > If we want to be ABI compatible, I'm afraid it needs to be 16 byte aligned > only. > We don't align aligned(64) structs to 64 bytes either, even with -mavx. >
That is because we couldn't align stack before gcc 4.4. We may use 256bit aligned insns to copy 32byte aligned memory. It is odd when 32byte aligned type may not be 32byte aligned when passed on stack. We may not have a choice before gcc 4.4. I don't see why we have to do it now. We can always issue a warning like what we did for other ABI changes. But I have no strong opinions on how to fix it. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44948
