Re: [PATCH] x86: Add *one_cmplqi_ext_2

[Uros Bizjak]

On Sat, Aug 2, 2025 at 3:22 AM H.J. Lu <hjl.to...@gmail.com> wrote:
>
> After
>
> commit 965564eafb721f8000013a3112f1bba8d8fae32b
> Author: Richard Sandiford <richard.sandif...@arm.com>
> Date:   Tue Jul 29 15:58:34 2025 +0100
>
>     simplify-rtx: Simplify subregs of logic ops
>
> combine generates
>
> (set (zero_extract:SI (reg/v:SI 101 [ a ])
>         (const_int 8 [0x8])
>         (const_int 8 [0x8]))
>     (not:SI (sign_extract:SI (reg:SI 107 [ b ])
>             (const_int 8 [0x8])
>             (const_int 8 [0x8]))))
>
> instead of
>
> (set (zero_extract:SI (reg/v:SI 101 [ a ])
>         (const_int 8 [0x8])
>         (const_int 8 [0x8]))
>     (subreg:SI (not:QI (subreg:QI (sign_extract:SI (reg:SI 107 [ b ])
>                     (const_int 8 [0x8])
>                     (const_int 8 [0x8])) 0)) 0))
>
> Add *one_cmplqi_ext<mode>_2 to support the new pattern.
>
>         PR target/121306
>         * config/i386/i386.md (*one_cmplqi_ext<mode>_2): New.

Why not just change the old pattern? I'd expect that the old form is
now obsolete.

Uros,