On Thu, Dec 20, 2018 at 05:34:54PM -0600, Aaron Sawdey wrote:
> On 12/20/18 3:51 AM, Segher Boessenkool wrote:
> > On Wed, Dec 19, 2018 at 01:53:05PM -0600, Aaron Sawdey wrote:
> >> Because of POWER9 dd2.1 issues with certain unaligned vsx instructions
> >> to cache inhibited memory, here is a patch that keeps memmove (and memcpy)
> >> inline expansion from doing unaligned vector or using vector load/store
> >> other than lvx/stvx. More description of the issue is here:
> >>
> >> https://patchwork.ozlabs.org/patch/814059/
> >>
> >> OK for trunk if bootstrap/regtest ok?
> >
> > Okay, but see below.
> >
> [snip]
> >
> > This is extraordinarily clumsy :-) Maybe something like:
> >
> > static rtx
> > gen_lvx_v4si_move (rtx dest, rtx src)
> > {
> > gcc_assert (!(MEM_P (dest) && MEM_P (src));
> > gcc_assert (GET_MODE (dest) == V4SImode && GET_MODE (src) == V4SImode);
> > if (MEM_P (dest))
> > return gen_altivec_stvx_v4si_internal (dest, src);
> > else if (MEM_P (src))
> > return gen_altivec_lvx_v4si_internal (dest, src);
> > else
> > gcc_unreachable ();
> > }
> >
> > (Or do you allow VOIDmode for src as well?) Anyway, at least get rid of
> > the useless extra variable.
>
> I think this should be better:
The gcc_unreachable at the end catches the non-mem to non-mem case.
> static rtx
> gen_lvx_v4si_move (rtx dest, rtx src)
> {
> gcc_assert ((MEM_P (dest) && !MEM_P (src)) || (MEM_P (src) &&
> !MEM_P(dest)));
But if you prefer this, how about
{
gcc_assert (MEM_P (dest) ^ MEM_P (src));
gcc_assert (GET_MODE (dest) == V4SImode && GET_MODE (src) == V4SImode);
if (MEM_P (dest))
return gen_altivec_stvx_v4si_internal (dest, src);
else
return gen_altivec_lvx_v4si_internal (dest, src);
}
:-)
Segher
