public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug c/94573] New: Optimizer produces suboptimal code related to -fstore-merging
@ 2020-04-13 4:59 zhongyunde at tom dot com
2020-04-14 7:12 ` [Bug tree-optimization/94573] " rguenth at gcc dot gnu.org
` (6 more replies)
0 siblings, 7 replies; 8+ messages in thread
From: zhongyunde at tom dot com @ 2020-04-13 4:59 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94573
Bug ID: 94573
Summary: Optimizer produces suboptimal code related to
-fstore-merging
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: zhongyunde at tom dot com
Target Milestone: ---
For the following code, we can known init the array C000016DD is always
consecutive, so we can use the more bigger mode size.
test base on the x86-64 gcc 9.2 on https://gcc.godbolt.org/, now it is still
handled DWORD by DWORD, and we except optimize it with QWORD or more bigger
size.
extern signed int C000016DD[43][12];
void C00001F93(int index)
{
C000016DD[index][0] = 0;
C000016DD[index][1] = 0;
C000016DD[index][2] = 0;
C000016DD[index][3] = 0;
C000016DD[index][4] = 0;
C000016DD[index][5] = 0;
C000016DD[index][6] = 0;
C000016DD[index][7] = 0;
return;
}
============= related assemble =============
C00001F93(int):
movsx rdi, edi
lea rax, [rdi+rdi*2]
sal rax, 4
mov DWORD PTR C000016DD[rax], 0
mov DWORD PTR C000016DD[rax+4], 0
mov DWORD PTR C000016DD[rax+8], 0
mov DWORD PTR C000016DD[rax+12], 0
mov DWORD PTR C000016DD[rax+16], 0
mov DWORD PTR C000016DD[rax+20], 0
mov DWORD PTR C000016DD[rax+24], 0
mov DWORD PTR C000016DD[rax+28], 0
ret
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/94573] Optimizer produces suboptimal code related to -fstore-merging
2020-04-13 4:59 [Bug c/94573] New: Optimizer produces suboptimal code related to -fstore-merging zhongyunde at tom dot com
@ 2020-04-14 7:12 ` rguenth at gcc dot gnu.org
2020-04-14 8:45 ` jakub at gcc dot gnu.org
` (5 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: rguenth at gcc dot gnu.org @ 2020-04-14 7:12 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94573
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution|--- |FIXED
Known to fail| |9.3.1
Known to work| |10.0
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
I see
C00001F93:
.LFB0:
.cfi_startproc
movslq %edi, %rdi
leaq (%rdi,%rdi,2), %rax
salq $4, %rax
movq $0, C000016DD(%rax)
movq $0, C000016DD+8(%rax)
movq $0, C000016DD+16(%rax)
movq $0, C000016DD+24(%rax)
ret
with GCC 10. Confirmed it uses 4 byte moves with GCC 9. Fixed in GCC 10 thus.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/94573] Optimizer produces suboptimal code related to -fstore-merging
2020-04-13 4:59 [Bug c/94573] New: Optimizer produces suboptimal code related to -fstore-merging zhongyunde at tom dot com
2020-04-14 7:12 ` [Bug tree-optimization/94573] " rguenth at gcc dot gnu.org
@ 2020-04-14 8:45 ` jakub at gcc dot gnu.org
2020-04-14 8:56 ` ebotcazou at gcc dot gnu.org
` (4 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: jakub at gcc dot gnu.org @ 2020-04-14 8:45 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94573
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |ebotcazou at gcc dot gnu.org,
| |jakub at gcc dot gnu.org
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
In particular, fixed with r10-3575-g629387a6586a753166f5cf53d587026a34362523
I thought that commit was about store merging with non-call-expceptions, but
apparently it affects more.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/94573] Optimizer produces suboptimal code related to -fstore-merging
2020-04-13 4:59 [Bug c/94573] New: Optimizer produces suboptimal code related to -fstore-merging zhongyunde at tom dot com
2020-04-14 7:12 ` [Bug tree-optimization/94573] " rguenth at gcc dot gnu.org
2020-04-14 8:45 ` jakub at gcc dot gnu.org
@ 2020-04-14 8:56 ` ebotcazou at gcc dot gnu.org
2020-04-14 10:29 ` rguenth at gcc dot gnu.org
` (3 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: ebotcazou at gcc dot gnu.org @ 2020-04-14 8:56 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94573
--- Comment #3 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> In particular, fixed with r10-3575-g629387a6586a753166f5cf53d587026a34362523
> I thought that commit was about store merging with non-call-expceptions, but
> apparently it affects more.
Possibly the adjust_bit_pos change.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/94573] Optimizer produces suboptimal code related to -fstore-merging
2020-04-13 4:59 [Bug c/94573] New: Optimizer produces suboptimal code related to -fstore-merging zhongyunde at tom dot com
` (2 preceding siblings ...)
2020-04-14 8:56 ` ebotcazou at gcc dot gnu.org
@ 2020-04-14 10:29 ` rguenth at gcc dot gnu.org
2020-04-14 10:39 ` jakub at gcc dot gnu.org
` (2 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: rguenth at gcc dot gnu.org @ 2020-04-14 10:29 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94573
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Means we should add the testcase?
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/94573] Optimizer produces suboptimal code related to -fstore-merging
2020-04-13 4:59 [Bug c/94573] New: Optimizer produces suboptimal code related to -fstore-merging zhongyunde at tom dot com
` (3 preceding siblings ...)
2020-04-14 10:29 ` rguenth at gcc dot gnu.org
@ 2020-04-14 10:39 ` jakub at gcc dot gnu.org
2020-04-14 11:08 ` zhongyunde at huawei dot com
2020-04-14 14:15 ` cvs-commit at gcc dot gnu.org
6 siblings, 0 replies; 8+ messages in thread
From: jakub at gcc dot gnu.org @ 2020-04-14 10:39 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94573
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I'll handle it.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/94573] Optimizer produces suboptimal code related to -fstore-merging
2020-04-13 4:59 [Bug c/94573] New: Optimizer produces suboptimal code related to -fstore-merging zhongyunde at tom dot com
` (4 preceding siblings ...)
2020-04-14 10:39 ` jakub at gcc dot gnu.org
@ 2020-04-14 11:08 ` zhongyunde at huawei dot com
2020-04-14 14:15 ` cvs-commit at gcc dot gnu.org
6 siblings, 0 replies; 8+ messages in thread
From: zhongyunde at huawei dot com @ 2020-04-14 11:08 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94573
--- Comment #6 from vfdff <zhongyunde at huawei dot com> ---
Created attachment 48267
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48267&action=edit
only get the adjust_bit_pos change
base on the adjust_bit_pos change only, I test it on the gcc 9, and find it
take effect.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/94573] Optimizer produces suboptimal code related to -fstore-merging
2020-04-13 4:59 [Bug c/94573] New: Optimizer produces suboptimal code related to -fstore-merging zhongyunde at tom dot com
` (5 preceding siblings ...)
2020-04-14 11:08 ` zhongyunde at huawei dot com
@ 2020-04-14 14:15 ` cvs-commit at gcc dot gnu.org
6 siblings, 0 replies; 8+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2020-04-14 14:15 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94573
--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:
https://gcc.gnu.org/g:66b8801141f5c1a65613b8f42501e8cd4b9195d9
commit r10-7717-g66b8801141f5c1a65613b8f42501e8cd4b9195d9
Author: Jakub Jelinek <jakub@redhat.com>
Date: Tue Apr 14 16:14:47 2020 +0200
testsuite: Add testcase for already fixed PR [PR94573]
2020-04-14 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/94573
* gcc.dg/store_merging_30.c: New test.
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2020-04-14 14:15 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-04-13 4:59 [Bug c/94573] New: Optimizer produces suboptimal code related to -fstore-merging zhongyunde at tom dot com
2020-04-14 7:12 ` [Bug tree-optimization/94573] " rguenth at gcc dot gnu.org
2020-04-14 8:45 ` jakub at gcc dot gnu.org
2020-04-14 8:56 ` ebotcazou at gcc dot gnu.org
2020-04-14 10:29 ` rguenth at gcc dot gnu.org
2020-04-14 10:39 ` jakub at gcc dot gnu.org
2020-04-14 11:08 ` zhongyunde at huawei dot com
2020-04-14 14:15 ` cvs-commit at gcc dot gnu.org
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).