https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115683
--- Comment #5 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Hongtao Liu from comment #0)
> g++: g++.target/i386/pr100637-1b.C
> g++: g++.target/i386/pr100637-1w.C
> g++: g++.target/i386/pr103861-1.C
>
> There're extra 1 pcmpeq instruction generated in below 3 testcase for
> comparison of GTU, x86 doesn't support native GTU comparison, but use
> psubusw + pcmpeq + pcmpeq, the second pcmpeq is used to negate the mask, and
> the negate can be eliminated in vcond{,u,eq} expander by just swapping
> if_true and if_else.
How to do that? The output from vec_cmpu is a mask value in the output register
that is used by vcond_mask as an input. I fail to see how the swap of if_true
and if_false operands (in vcond_mask RTX) can be communicated from vec_cmpu to
vcond_mask.
