Re: [PATCH][RFC][x86] Fix PR91154, add SImode smax, allow SImode add in SSE regs

[Jakub Jelinek]

On Fri, Aug 09, 2019 at 11:25:30AM +0200, Richard Biener wrote:
>   0.65 │1e0:   vpxor  %xmm0,%xmm0,%xmm0
>   0.32 │       vpmaxs -0x10(%rsp),%xmm0,%xmm0
>  40.45 │       vmovd  %xmm0,%eax
>   2.45 │       imul   %r8d,%eax

Shouldn't we hoist the vpxor before the loop?  Is it STV being done too late
that we don't do that anymore?  Couldn't e.g. STV itself detect that and put
the clearing instruction before the loop instead of right before the minmax?

        Jakub