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From: "crazylht at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/107546] [10/11/12/13 Regression] simd, redundant pcmpeqb and pxor
Date: Mon, 07 Nov 2022 08:27:47 +0000	[thread overview]
Message-ID: <bug-107546-4-xDnnv3HQHM@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-107546-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107546

--- Comment #7 from Hongtao.liu <crazylht at gmail dot com> ---
(In reply to Hongtao.liu from comment #3)
> Failed to match this instruction:
> (set (reg:V16QI 95)
>     (eq:V16QI (gt:V16QI (subreg:V16QI (reg:V2DI 89 [ MEM[(const __m128i_u *
> {ref-all})p_2(D)] ]) 0)
>             (mem/u/c:V16QI (symbol_ref/u:DI ("*.LC0") [flags 0x2]) [0  S16
> A128]))
>         (const_vector:V16QI [
>                 (const_int 0 [0]) repeated x16
>             ])))
> 
> 
> I think rtl can simplify vector comparison
> 
> (eq (gt op1 op2) const0_rtx) to just (gt op2 op1).

No, it's not, it's (le op1 op2) which is not supported under sse2 ,and this is
the exact reason we do negate the result in the backend.

  parent reply	other threads:[~2022-11-07  8:27 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-07  6:39 [Bug rtl-optimization/107546] New: " i.nixman at autistici dot org
2022-11-07  6:51 ` [Bug target/107546] " pinskia at gcc dot gnu.org
2022-11-07  6:58 ` [Bug target/107546] [10/11/12/13 Regression] " pinskia at gcc dot gnu.org
2022-11-07  7:07 ` rguenth at gcc dot gnu.org
2022-11-07  7:07 ` crazylht at gmail dot com
2022-11-07  7:14 ` crazylht at gmail dot com
2022-11-07  7:16 ` glisse at gcc dot gnu.org
2022-11-07  7:20 ` pinskia at gcc dot gnu.org
2022-11-07  8:27 ` crazylht at gmail dot com [this message]
2022-11-07 10:22 ` jakub at gcc dot gnu.org
2022-11-07 12:02 ` jakub at gcc dot gnu.org
2022-11-07 12:05 ` i.nixman at autistici dot org
2022-11-07 13:47 ` i.nixman at autistici dot org
2022-11-08 11:24 ` cvs-commit at gcc dot gnu.org
2022-11-08 11:59 ` [Bug target/107546] [10/11/12 " jakub at gcc dot gnu.org
2022-11-10 10:48 ` cvs-commit at gcc dot gnu.org
2023-07-07 10:44 ` [Bug target/107546] [11/12 " rguenth at gcc dot gnu.org

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