https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92651
--- Comment #11 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to rguent...@suse.de from comment #8)
> Sure. Another option would be to enhance STV even further
> (or add some peephole patterns - combine runs before STV2) to
> transform the
>
> psubd xmm3, xmm0
> psubd xmm0, xmm1
> pmaxsd xmm0, xmm3
>
> into
>
> psubd %xmm3, %xmm0
> pabsd %xmm0, %xmm0
>
> for enhancing STV that means adding abs() patterns (or adding
> combine-like matching to the pass which I'd suggest not do).
>
> Clearly that the above conversion isn't done is a generic
> missed optimization. Maybe you can benchmark that as well
> though I guess it won't come near the xor variant?
After PR97873 introduced abs to STV:
int test (int x, int y)
{
return abs (x - y);
}
cc1 -O2 -msse4.1 -mstv -m32:
movd 4(%esp), %xmm0
movd 8(%esp), %xmm1
psubd %xmm1, %xmm0
pabsd %xmm0, %xmm0
movd %xmm0, %eax
