https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94452
Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|I386 ABI: How to determine |I386 ABI: How to determine |the alignment of struct or |the alignment arguments on |union determined when |the stack of struct or |passes them on stack? |union for argument passing Status|WAITING |UNCONFIRMED Ever confirmed|1 |0 --- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to ChenLiu from comment #2) > (In reply to Richard Biener from comment #1) > > I see gx aligned to 64 bytes (as I expected). Can you be more specific as > > to what target you tested? > > I tested on i386 target. I think you may misunderstand what I mean. The gx > will align to 4 byte when passing it on stack. I think this should belong to > calling conventions. Ah, OK. IIRC the psABI does not factor in over/under alignment but only size and kind of (sub-)objects so eventually extra copy-in/out is required to have the callee see arguments of the desired alignment. HJ can probably clarify. Note bugzilla isn't really for this kind of questions, there's a psABI mailing list somewhere.