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From: "hjl.tools at gmail dot com" <sourceware-bugzilla@sourceware.org>
To: glibc-bugs@sourceware.org
Subject: [Bug string/27457] vzeroupper use in AVX2 multiarch string functions cause HTM aborts
Date: Mon, 01 Mar 2021 13:21:29 +0000	[thread overview]
Message-ID: <bug-27457-131-2dfSdbW56r@http.sourceware.org/bugzilla/> (raw)
In-Reply-To: <bug-27457-131@http.sourceware.org/bugzilla/>

https://sourceware.org/bugzilla/show_bug.cgi?id=27457

--- Comment #10 from H.J. Lu <hjl.tools at gmail dot com> ---
(In reply to Florian Weimer from comment #6)
> (In reply to H.J. Lu from comment #5)
> > I added another set of AVX/AVX2 functions to support RTM.  You can use
> > libcpu-rt-c.so:
> > 
> > https://gitlab.com/cpu-rt/glibc/-/wikis/libcpu-rt-c.so-to-avoid-vzeroupper-
> > in-RTM-region
> > 
> > to try it out.
> 
> The sources do not seem to show the selection logic.
> __memset_avx2_unaligned_rtm seems to simply have dropped the VZEROUPPER
> instruction, which can't be good for general application performance.

memset-avx2-unaligned-erms-rtm.S has

#define ZERO_UPPER_VEC_REGISTERS_RETURN \
  ZERO_UPPER_VEC_REGISTERS_RETURN_XTEST

0000000000000040 <__memset_avx2_unaligned_rtm>:
  40:   f3 0f 1e fa             endbr64 
  44:   c5 f9 6e c6             vmovd  %esi,%xmm0
  48:   48 89 f8                mov    %rdi,%rax
  4b:   c4 e2 7d 78 c0          vpbroadcastb %xmm0,%ymm0
  50:   48 83 fa 20             cmp    $0x20,%rdx
  54:   0f 82 0b 01 00 00       jb     165
<__memset_avx2_unaligned_erms_rtm+0xc5>
  5a:   48 83 fa 40             cmp    $0x40,%rdx
  5e:   77 75                   ja     d5
<__memset_avx2_unaligned_erms_rtm+0x35>
  60:   c5 fe 7f 44 17 e0       vmovdqu %ymm0,-0x20(%rdi,%rdx,1)
  66:   c5 fe 7f 07             vmovdqu %ymm0,(%rdi)
  6a:   e9 84 00 00 00          jmp    f3
<__memset_avx2_unaligned_erms_rtm+0x53>
  6f:   90                      nop
,,,
00000000000000a0 <__memset_avx2_unaligned_erms_rtm>:
  a0:   f3 0f 1e fa             endbr64 
  a4:   c5 f9 6e c6             vmovd  %esi,%xmm0
  a8:   48 89 f8                mov    %rdi,%rax
  ab:   c4 e2 7d 78 c0          vpbroadcastb %xmm0,%ymm0
  b0:   48 83 fa 20             cmp    $0x20,%rdx
  b4:   0f 82 ab 00 00 00       jb     165
<__memset_avx2_unaligned_erms_rtm+0xc5>
  ba:   48 83 fa 40             cmp    $0x40,%rdx
  be:   77 0c                   ja     cc
<__memset_avx2_unaligned_erms_rtm+0x2c>
  c0:   c5 fe 7f 44 17 e0       vmovdqu %ymm0,-0x20(%rdi,%rdx,1)
  c6:   c5 fe 7f 07             vmovdqu %ymm0,(%rdi)
  ca:   eb 27                   jmp    f3
<__memset_avx2_unaligned_erms_rtm+0x53>
  cc:   48 3b 15 00 00 00 00    cmp    0x0(%rip),%rdx        # d3
<__memset_avx2_unaligned_erms_rtm+0x33>
  d3:   77 9f                   ja     74 <__memset_avx2_erms_rtm+0x4>
  d5:   48 81 fa 80 00 00 00    cmp    $0x80,%rdx
  dc:   77 22                   ja     100
<__memset_avx2_unaligned_erms_rtm+0x60>
  de:   c5 fe 7f 07             vmovdqu %ymm0,(%rdi)
  e2:   c5 fe 7f 47 20          vmovdqu %ymm0,0x20(%rdi)
  e7:   c5 fe 7f 44 17 e0       vmovdqu %ymm0,-0x20(%rdi,%rdx,1)
  ed:   c5 fe 7f 44 17 c0       vmovdqu %ymm0,-0x40(%rdi,%rdx,1)
  f3:   0f 01 d6                xtest  
  f6:   74 04                   je     fc
<__memset_avx2_unaligned_erms_rtm+0x5c>
  f8:   c5 fc 77                vzeroall 
  fb:   c3                      ret    
  fc:   c5 f8 77                vzeroupper 
  ff:   c3                      ret

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  parent reply	other threads:[~2021-03-01 13:21 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-22 12:40 [Bug string/27457] New: " rguenth at gcc dot gnu.org
2021-02-22 12:40 ` [Bug string/27457] " rguenth at gcc dot gnu.org
2021-02-22 14:50 ` matz at suse dot de
2021-02-22 15:00 ` rguenth at gcc dot gnu.org
2021-02-22 15:26 ` hjl.tools at gmail dot com
2021-02-22 15:26 ` hjl.tools at gmail dot com
2021-02-22 18:45 ` fweimer at redhat dot com
2021-02-23  9:44 ` roman.dementiev at intel dot com
2021-02-27  2:39 ` hjl.tools at gmail dot com
2021-02-27  7:34 ` rguenther at suse dot de
2021-02-28 14:53 ` hjl.tools at gmail dot com
2021-03-01 11:32 ` fweimer at redhat dot com
2021-03-01 12:24 ` mliska at suse dot cz
2021-03-01 12:47 ` rguenther at suse dot de
2021-03-01 13:13 ` roman.dementiev at intel dot com
2021-03-01 13:19 ` fweimer at redhat dot com
2021-03-01 13:21 ` hjl.tools at gmail dot com [this message]
2021-03-01 13:24 ` hjl.tools at gmail dot com
2021-03-01 13:27 ` hjl.tools at gmail dot com
2021-03-01 13:29 ` hjl.tools at gmail dot com
2021-03-01 13:44 ` rguenth at gcc dot gnu.org
2021-03-01 14:05 ` hjl.tools at gmail dot com
2021-03-01 14:14 ` rguenther at suse dot de
2021-03-01 14:25 ` rguenth at gcc dot gnu.org
2021-03-01 14:37 ` hjl.tools at gmail dot com
2021-03-01 14:47 ` hjl.tools at gmail dot com
2021-03-01 14:49 ` rguenth at gcc dot gnu.org
2021-03-01 14:53 ` rguenth at gcc dot gnu.org
2021-03-01 15:19 ` hjl.tools at gmail dot com
2021-03-01 23:39 ` hjl.tools at gmail dot com
2021-03-05 16:54 ` hjl.tools at gmail dot com
2021-03-11 10:42 ` rguenth at gcc dot gnu.org
2021-03-16 13:53 ` rguenth at gcc dot gnu.org
2021-03-16 14:12 ` hjl.tools at gmail dot com
2021-03-29 23:00 ` hjl.tools at gmail dot com
2022-01-27 20:21 ` cvs-commit at gcc dot gnu.org
2022-01-27 20:23 ` cvs-commit at gcc dot gnu.org
2022-01-27 20:47 ` cvs-commit at gcc dot gnu.org
2022-01-27 20:47 ` cvs-commit at gcc dot gnu.org
2022-01-27 20:48 ` cvs-commit at gcc dot gnu.org
2022-01-27 22:41 ` cvs-commit at gcc dot gnu.org
2022-01-28  2:24 ` hjl.tools at gmail dot com

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