https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110406
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |ABI
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #5)
> (In reply to ibuclaw from comment #3)
> > (In reply to Andrew Pinski from comment #2)
> > > >structs have been set the wrong mode
> > >
> > > No, they don't have wrong mode, just the x86_64 backend is broken, see bug
> > > 102027 comment #7 specifically.
> > I think they do.
> >
> > On 64-bit, I expect the mode set by compute_record_mode to be TImode.
> > However what I'm instead seeing is BLKmode. This tells me I might be calling
> > it too early, and some fields yet to have their DECL_SIZE set.
>
> Unless the struct has the alignment of TImode, it should be BLKmode ...
here is a C testcase to get it returned into vector register (incorrectly due
to the alignment being set to 32):
```
typedef unsigned uint;
struct cpuid_abcd_t
{
uint eax;
uint ebx;
uint ecx;
uint edx;
} __attribute__((aligned(8*4)));
struct cpuid_abcd_t
cpuid_insn(const uint in_eax)
{
struct cpuid_abcd_t ret={};
asm (
"cpuid"
:
"=a" ( ret.eax ),
"=b" ( ret.ebx ),
"=c" ( ret.ecx ),
"=d" ( ret.edx )
:
"a" ( in_eax )
:
);
return ret;
}
```
Which itself is GCC 12+ regression too ...
