On Mon, Jul 29, 2024 at 02:59:58PM +0200, Jakub Jelinek wrote:
> On Mon, Jul 29, 2024 at 02:52:24PM +0200, Richard Biener wrote:
> > > mode = GET_MODE_INNER (mode);
> > > ?
> >
> > I specifically wanted to avoid this (at least for the purpose of the
> > hook).
> >
> > > I mean say XCmode has similar problems as XFmode, or
> > > V4SFmode as SFmode if i?86 -mno-sse.
> > > Though, admittedly, with i?86 -msse2 -mfpmath=387 perhaps some vector
> > > modes
> > > could work, which would argue for passing even vector modes to the hook.
> > > Though the GET_MODE_BITSIZE != GET_MODE_PRECISION check then wants the
> > > inner
> > > modes maybe.
> >
> > We do not support vector inner modes with padding. I didn't think of
> > XCmode - though precision is 160 here and size 192, so the padding
> > check should work there as well.
>
> One thing is XCmode, another one is SCmode/DCmode/HCmode/BCmode without
> -mfpmath=sse, there the target hook should say that it can't transfer bits.
>
> For the vector V*[SDHB]Fmode it really depends on if it will be lowered to
> scalar or vector moves.
>
> And, for the GET_MODE_INNER, I also meant it for Aarch64/RISC-V VL vectors,
> I think those should be considered as true by the hook, not false
> because maybe_ne.
Maybe the vector modes are ok on ia32, given -O2 -m32 -mno-sse
struct S { _Complex _Float16 a; __attribute__((vector_size (8 * sizeof
(_Float16)))) _Float16 b; };
void
foo (struct S *p, struct S *q)
{
p->a = q->a;
q->b = p->b;
}
struct T { _Complex _Float32 a; __attribute__((vector_size (8 * sizeof
(_Float32)))) _Float32 b; };
void
bar (struct T *p, struct T *q)
{
p->a = q->a;
q->b = p->b;
}
But SCmode/DCmode is not.
Jakub
