[Bug tree-optimization/115843] [14/15 Regression] 531.deepsjeng_r fails to verify with -O3 -march=znver4 --param vect-partial-vector-usage=2

[hongyuw at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115843

--- Comment #11 from Hongyu Wang <hongyuw at gcc dot gnu.org> ---
(In reply to Hongtao Liu from comment #10)
> > But using kmovw for QImode mask is not correct as we don't know the value in
> > gpr. Perhaps we'd consider restrict the kmovb under avx512dq only.
> 
> Why? as long as we only care about lower 8 bits, vmovw should be fine.

Ah yes, I was wrong. As long as the usage of mask did not touch those extra
bits there's nothing wrong. And suppose the QI->HI conversion will use zext
sematic so we can still get correct value.