https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101185
--- Comment #3 from Hongtao.liu <crazylht at gmail dot com> ---
(In reply to Hongtao.liu from comment #1)
> Alloc order is just another kind of cost which can be compensated by
> increasing cost of mask->integer and integer->mask.
>
> With below patch , pr96814 wouldn't generate any mask intructions execept
> for
>
> kmovd %eax, %k1
> vpcmpeqd %ymm1, %ymm1, %ymm1
> vmovdqu8 %ymm1, %ymm0{%k1}{z}
>
> which is what we want.
>
>
> modified gcc/config/i386/i386.md
> @@ -1335,7 +1335,7 @@
> (define_insn "*cmp<mode>_ccz_1"
> [(set (reg FLAGS_REG)
> (compare (match_operand:SWI1248_AVX512BWDQ_64 0
> - "nonimmediate_operand" "<r>,?m<r>,$k")
> + "nonimmediate_operand" "<r>,?m<r>,*k")
> (match_operand:SWI1248_AVX512BWDQ_64 1 "const0_operand")))]
> "TARGET_AVX512F && ix86_match_ccmode (insn, CCZmode)"
> "@
> modified gcc/config/i386/x86-tune-costs.h
> @@ -2768,7 +2768,7 @@ struct processor_costs intel_cost = {
> {6, 6, 6, 6, 6}, /* cost of storing SSE registers
> in 32,64,128,256 and 512-bit */
> 4, 4, /* SSE->integer and integer->SSE moves
> */
> - 4, 4, /* mask->integer and integer->mask
> moves */
> + 6, 6, /* mask->integer and integer->mask
> moves */
I changed intel_cost just to validate 1 unit more cost is also enough for
-mtune=intel to prevent generation of mask instructions.
