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From: "wwwhhhyyy333 at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/103771] New: Missed vectorization under -mavx512f -mavx512vl after r12-5489
Date: Mon, 20 Dec 2021 08:59:14 +0000 [thread overview]
Message-ID: <bug-103771-4@http.gcc.gnu.org/bugzilla/> (raw)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103771
Bug ID: 103771
Summary: Missed vectorization under -mavx512f -mavx512vl after
r12-5489
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: wwwhhhyyy333 at gmail dot com
Target Milestone: ---
cat vect.c
typedef unsigned char uint8_t;
static uint8_t x264_clip_uint8( int x )
{
return x&(~255) ? (-x)>>31 : x;
}
void mc_weight( uint8_t * __restrict dst, uint8_t * __restrict src, int
i_width, int i_scale)
{
for( int x = 0; x < i_width; x++ )
dst[x] = x264_clip_uint8(src[x] * i_scale);
}
It can not be vectorized with -mavx512f -mavx512vl, but can be vectorized with
-mavx2, See https://godbolt.org/z/M1jx161f6
The commit https://gcc.gnu.org/cgi-bin/gcc-gitref.cgi?r=r12-5489 converts (x &
(~255)) == 0 to x <= 255, which may trigger some missing pattern with
-mavx512vl.
Also an 1.5% regression was found on -march=cascadelake due to missing 128bit
epilogue for this loop.
next reply other threads:[~2021-12-20 8:59 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-20 8:59 wwwhhhyyy333 at gmail dot com [this message]
2021-12-20 11:45 ` [Bug target/103771] [12 Regression] " pinskia at gcc dot gnu.org
2022-01-04 15:31 ` tnfchris at gcc dot gnu.org
2022-01-05 9:00 ` crazylht at gmail dot com
2022-01-13 8:43 ` crazylht at gmail dot com
2022-01-13 9:02 ` crazylht at gmail dot com
2022-01-13 9:04 ` crazylht at gmail dot com
2022-01-13 9:28 ` rguenth at gcc dot gnu.org
2022-01-13 9:50 ` rguenth at gcc dot gnu.org
2022-01-13 10:04 ` crazylht at gmail dot com
2022-01-13 10:11 ` rsandifo at gcc dot gnu.org
2022-01-13 10:22 ` crazylht at gmail dot com
2022-01-13 10:43 ` crazylht at gmail dot com
2022-01-13 10:44 ` rguenther at suse dot de
2022-01-13 10:49 ` rguenther at suse dot de
2022-01-13 10:50 ` crazylht at gmail dot com
2022-01-13 12:40 ` crazylht at gmail dot com
2022-01-13 13:42 ` rguenther at suse dot de
2022-01-13 14:42 ` crazylht at gmail dot com
2022-01-14 9:40 ` rsandifo at gcc dot gnu.org
2022-01-14 10:18 ` rguenth at gcc dot gnu.org
2022-01-17 8:22 ` crazylht at gmail dot com
2022-01-18 8:31 ` crazylht at gmail dot com
2022-01-18 8:36 ` crazylht at gmail dot com
2022-01-18 10:44 ` rguenther at suse dot de
2022-01-18 10:49 ` pinskia at gcc dot gnu.org
2022-01-19 6:03 ` crazylht at gmail dot com
2022-01-19 6:10 ` pinskia at gcc dot gnu.org
2022-01-19 6:25 ` crazylht at gmail dot com
2022-01-19 7:44 ` rguenth at gcc dot gnu.org
2022-01-19 8:33 ` crazylht at gmail dot com
2022-01-19 8:48 ` rguenther at suse dot de
2022-01-20 8:52 ` cvs-commit at gcc dot gnu.org
2022-01-27 6:03 ` crazylht at gmail dot com
2022-02-01 5:21 ` pinskia at gcc dot gnu.org
2022-02-01 16:13 ` law at gcc dot gnu.org
2022-02-01 16:18 ` pinskia at gcc dot gnu.org
2022-02-13 9:58 ` cvs-commit at gcc dot gnu.org
2022-02-14 7:36 ` rguenth at gcc dot gnu.org
2022-02-14 7:45 ` crazylht at gmail dot com
2022-02-14 7:53 ` rguenth at gcc dot gnu.org
2022-02-17 11:01 ` cvs-commit at gcc dot gnu.org
2023-04-26 6:55 ` [Bug target/103771] [12/13/14 " rguenth at gcc dot gnu.org
2023-05-06 23:21 ` pinskia at gcc dot gnu.org
2023-05-08 7:38 ` cvs-commit at gcc dot gnu.org
2023-05-08 7:39 ` pinskia at gcc dot gnu.org
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