https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94962
--- Comment #7 from Nemo ---
(In reply to Hongtao.liu from comment #6)
>
> vmovdqa xmm0, xmm0 is not redundant here, it would clear up 128-256 bit
> which is the meaning of `zext`.
No, it is redundant because "vpcmpeqd xmm0, xmm0, xmm0" already
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94962
--- Comment #5 from Nemo ---
(In reply to Jakub Jelinek from comment #2)
I would be happy if GCC could just emit optimal code (single vcmpeqd
instruction) for this useful constant:
_mm256_set_m128i(_mm_setzero_si128(), _mm_set1_epi8(-1))
a
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: n...@self-evident.org
Target Milestone: ---
Background: https://stackoverflow.com/q/61601902/
GCC emits an unnecessary "vmovdqa xmm0,xmm0" for the foll
