[Bug target/94452] I386 ABI: How to determine the alignment arguments on the stack of struct or union for argument passing

[chen3.liu at intel dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94452

--- Comment #5 from ChenLiu <chen3.liu at intel dot com> ---
(In reply to Richard Biener from comment #4)
> (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.

Thanks for your help.