Re: [PATCH 3/5] xtensa: Add some dedicated patterns that correspond to GIMPLE canonicalizations

[Max Filippov <jcmvbkbc@gmail.com>]

On Mon, Jun 13, 2022 at 8:54 PM Takayuki 'January June' Suwa
<jjsuwa_sys3175@yahoo.co.jp> wrote:
>
> This patch offers better RTL representations against straightforward
> derivations from some tree optimizers' canonicalized forms.
>
> - rounding up to even, such as '(x + (x & 1))', is canonicalized to
>   '((x + 1) & -2)', but the former is one instruction less than the latter
>   in Xtensa ISA.
> - signed greater or equal to zero as logical value '((signed)x >= 0)',
>   is canonicalized to '((unsigned)(x ^ -1) >> 31)', but the equivalent
>   '(((signed)x >> 31) + 1)' is one instruction less.
>
> gcc/ChangeLog:
>
>         * config/xtensa/xtensa.md (*round_up_to_even):
>         New insn-and-split pattern.
>         (*signed_ge_zero): Ditto.
> ---
>  gcc/config/xtensa/xtensa.md | 45 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 45 insertions(+)

Regtested for target=xtensa-linux-uclibc, no new regressions.
Committed to master.

-- 
Thanks.
-- Max