public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug rtl-optimization/29978] New: suboptimal code generation
@ 2006-11-25 18:22 vda dot linux at googlemail dot com
2007-07-21 23:36 ` [Bug rtl-optimization/29978] " vda dot linux at googlemail dot com
` (8 more replies)
0 siblings, 9 replies; 10+ messages in thread
From: vda dot linux at googlemail dot com @ 2006-11-25 18:22 UTC (permalink / raw)
To: gcc-bugs
With following testcase gcc 4.1.1 with -Os produces two back-to-back jumps:
"jump to L2 if less; jump to L2 if less-or-equal;" the first one is not needed.
-O2 is worse, but I usually use -Os anyway.
void g();
void f(long long v) {
if (v > 0777777777777LL)
g();
g();
}
/* gcc -v:
Target: i386-pc-linux-gnu
[skip]
Thread model: posix
gcc version 4.1.1
================
gcc -Os -fomit-frame-pointer -S tar.c
f:
cmpl $15, 8(%esp)
jl .L2 // not needed
jle .L2
call g
.L2:
jmp g
================
gcc -O2 -fomit-frame-pointer -S tar.c
f:
subl $12, %esp // not needed
cmpl $15, 20(%esp)
jl .L2 // not needed
jle .L2
call g
.p2align 2,,3
.L2:
addl $12, %esp // not needed
jmp g
*/
--
Summary: suboptimal code generation
Product: gcc
Version: 4.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: vda dot linux at googlemail dot com
GCC build triplet: i386-pc-linux-gnu
GCC host triplet: i386-pc-linux-gnu
GCC target triplet: i386-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29978
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug rtl-optimization/29978] suboptimal code generation
2006-11-25 18:22 [Bug rtl-optimization/29978] New: suboptimal code generation vda dot linux at googlemail dot com
@ 2007-07-21 23:36 ` vda dot linux at googlemail dot com
2007-12-14 11:05 ` [Bug rtl-optimization/29978] [4.0/4.1/4.2/4.3 Regression] redundant jumps aldot at gcc dot gnu dot org
` (7 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: vda dot linux at googlemail dot com @ 2007-07-21 23:36 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from vda dot linux at googlemail dot com 2007-07-21 23:36 -------
With 4.2.1 gcc regressed a bit:
gcc -Os -fomit-frame-pointer -S u.c
.file "u.c"
.text
.globl f
.type f, @function
f:
subl $12, %esp
cmpl $15, 20(%esp)
jl .L2
jle .L2
call g
.L2:
addl $12, %esp
jmp g
.size f, .-f
.ident "GCC: (GNU) 4.2.1"
.section .note.GNU-stack,"",@progbits
In addition to unnecessary jl, we have unnecessary stack manipulations.
(I created separate bug 32849 for this stack problem)
--
vda dot linux at googlemail dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
Version|4.1.1 |4.2.1
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29978
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug rtl-optimization/29978] [4.0/4.1/4.2/4.3 Regression] redundant jumps
2006-11-25 18:22 [Bug rtl-optimization/29978] New: suboptimal code generation vda dot linux at googlemail dot com
2007-07-21 23:36 ` [Bug rtl-optimization/29978] " vda dot linux at googlemail dot com
@ 2007-12-14 11:05 ` aldot at gcc dot gnu dot org
2007-12-14 11:24 ` aldot at gcc dot gnu dot org
` (6 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: aldot at gcc dot gnu dot org @ 2007-12-14 11:05 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from aldot at gcc dot gnu dot org 2007-12-14 11:05 -------
Confirmed. gcc-2.95.4 works as expected:
$ gcc-2.95 -Os -fomit-frame-pointer pr29978.i -S -o -
.file "pr29978.i"
.version "01.01"
gcc2_compiled.:
.text
.align 16
.globl f
.type f,@function
f:
subl $12,%esp
cmpl $15,20(%esp)
jle .L3
call g
.L3:
call g
addl $12,%esp
ret
.Lfe1:
.size f,.Lfe1-f
.ident "GCC: (GNU) 2.95.4 20011002 (Debian prerelease)"
--
aldot at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |aldot at gcc dot gnu dot org
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Keywords| |missed-optimization
Known to fail| |3.3 3.4.6 4.0.4 4.1.3 4.2.2
Known to work| |2.95.4
Last reconfirmed|0000-00-00 00:00:00 |2007-12-14 11:05:43
date| |
Summary|suboptimal code generation |[4.0/4.1/4.2/4.3 Regression]
| |redundant jumps
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29978
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug rtl-optimization/29978] [4.0/4.1/4.2/4.3 Regression] redundant jumps
2006-11-25 18:22 [Bug rtl-optimization/29978] New: suboptimal code generation vda dot linux at googlemail dot com
2007-07-21 23:36 ` [Bug rtl-optimization/29978] " vda dot linux at googlemail dot com
2007-12-14 11:05 ` [Bug rtl-optimization/29978] [4.0/4.1/4.2/4.3 Regression] redundant jumps aldot at gcc dot gnu dot org
@ 2007-12-14 11:24 ` aldot at gcc dot gnu dot org
2007-12-14 11:32 ` [Bug target/29978] " pinskia at gcc dot gnu dot org
` (5 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: aldot at gcc dot gnu dot org @ 2007-12-14 11:24 UTC (permalink / raw)
To: gcc-bugs
--
aldot at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |4.3.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29978
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug target/29978] [4.0/4.1/4.2/4.3 Regression] redundant jumps
2006-11-25 18:22 [Bug rtl-optimization/29978] New: suboptimal code generation vda dot linux at googlemail dot com
` (2 preceding siblings ...)
2007-12-14 11:24 ` aldot at gcc dot gnu dot org
@ 2007-12-14 11:32 ` pinskia at gcc dot gnu dot org
2007-12-14 13:04 ` jakub at gcc dot gnu dot org
` (4 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2007-12-14 11:32 UTC (permalink / raw)
To: gcc-bugs
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |pinskia at gcc dot gnu dot
| |org
Component|rtl-optimization |target
GCC build triplet|i386-pc-linux-gnu |
GCC host triplet|i386-pc-linux-gnu |
Target Milestone|4.3.0 |4.1.3
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29978
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug target/29978] [4.0/4.1/4.2/4.3 Regression] redundant jumps
2006-11-25 18:22 [Bug rtl-optimization/29978] New: suboptimal code generation vda dot linux at googlemail dot com
` (3 preceding siblings ...)
2007-12-14 11:32 ` [Bug target/29978] " pinskia at gcc dot gnu dot org
@ 2007-12-14 13:04 ` jakub at gcc dot gnu dot org
2007-12-14 18:01 ` jakub at gcc dot gnu dot org
` (3 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: jakub at gcc dot gnu dot org @ 2007-12-14 13:04 UTC (permalink / raw)
To: gcc-bugs
--
jakub at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|unassigned at gcc dot gnu |jakub at gcc dot gnu dot org
|dot org |
Status|NEW |ASSIGNED
Last reconfirmed|2007-12-14 11:05:43 |2007-12-14 13:03:59
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29978
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug target/29978] [4.0/4.1/4.2/4.3 Regression] redundant jumps
2006-11-25 18:22 [Bug rtl-optimization/29978] New: suboptimal code generation vda dot linux at googlemail dot com
` (4 preceding siblings ...)
2007-12-14 13:04 ` jakub at gcc dot gnu dot org
@ 2007-12-14 18:01 ` jakub at gcc dot gnu dot org
2007-12-14 18:31 ` [Bug target/29978] [4.0/4.1/4.2 " jakub at gcc dot gnu dot org
` (2 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: jakub at gcc dot gnu dot org @ 2007-12-14 18:01 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from jakub at gcc dot gnu dot org 2007-12-14 18:00 -------
Subject: Bug 29978
Author: jakub
Date: Fri Dec 14 18:00:39 2007
New Revision: 130938
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=130938
Log:
PR target/29978
* config/i386/i386.c (ix86_expand_branch): Optimize LE/LEU/GT/GTU
DImode comparisons against constant with all 1's in the lower word.
* gcc.target/i386/pr29978.c: New test.
Added:
trunk/gcc/testsuite/gcc.target/i386/pr29978.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/config/i386/i386.c
trunk/gcc/testsuite/ChangeLog
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29978
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug target/29978] [4.0/4.1/4.2 Regression] redundant jumps
2006-11-25 18:22 [Bug rtl-optimization/29978] New: suboptimal code generation vda dot linux at googlemail dot com
` (5 preceding siblings ...)
2007-12-14 18:01 ` jakub at gcc dot gnu dot org
@ 2007-12-14 18:31 ` jakub at gcc dot gnu dot org
2008-07-04 21:45 ` [Bug target/29978] [4.2 " jsm28 at gcc dot gnu dot org
2009-03-30 19:43 ` jsm28 at gcc dot gnu dot org
8 siblings, 0 replies; 10+ messages in thread
From: jakub at gcc dot gnu dot org @ 2007-12-14 18:31 UTC (permalink / raw)
To: gcc-bugs
------- Comment #4 from jakub at gcc dot gnu dot org 2007-12-14 18:30 -------
Fixed on the trunk.
--
jakub at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to work|2.95.4 |2.95.4 4.3.0
Summary|[4.0/4.1/4.2/4.3 Regression]|[4.0/4.1/4.2 Regression]
|redundant jumps |redundant jumps
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29978
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug target/29978] [4.2 Regression] redundant jumps
2006-11-25 18:22 [Bug rtl-optimization/29978] New: suboptimal code generation vda dot linux at googlemail dot com
` (6 preceding siblings ...)
2007-12-14 18:31 ` [Bug target/29978] [4.0/4.1/4.2 " jakub at gcc dot gnu dot org
@ 2008-07-04 21:45 ` jsm28 at gcc dot gnu dot org
2009-03-30 19:43 ` jsm28 at gcc dot gnu dot org
8 siblings, 0 replies; 10+ messages in thread
From: jsm28 at gcc dot gnu dot org @ 2008-07-04 21:45 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from jsm28 at gcc dot gnu dot org 2008-07-04 21:44 -------
Closing 4.1 branch.
--
jsm28 at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|[4.1/4.2 Regression] |[4.2 Regression] redundant
|redundant jumps |jumps
Target Milestone|4.1.3 |4.2.5
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29978
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug target/29978] [4.2 Regression] redundant jumps
2006-11-25 18:22 [Bug rtl-optimization/29978] New: suboptimal code generation vda dot linux at googlemail dot com
` (7 preceding siblings ...)
2008-07-04 21:45 ` [Bug target/29978] [4.2 " jsm28 at gcc dot gnu dot org
@ 2009-03-30 19:43 ` jsm28 at gcc dot gnu dot org
8 siblings, 0 replies; 10+ messages in thread
From: jsm28 at gcc dot gnu dot org @ 2009-03-30 19:43 UTC (permalink / raw)
To: gcc-bugs
------- Comment #6 from jsm28 at gcc dot gnu dot org 2009-03-30 19:42 -------
Closing 4.2 branch, fixed in 4.3.
--
jsm28 at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Known to fail|3.3 3.4.6 4.0.4 4.1.3 4.2.2 |3.3 3.4.6 4.0.4 4.1.3 4.2.2
| |4.2.5
Resolution| |FIXED
Target Milestone|4.2.5 |4.3.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29978
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2009-03-30 19:43 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2006-11-25 18:22 [Bug rtl-optimization/29978] New: suboptimal code generation vda dot linux at googlemail dot com
2007-07-21 23:36 ` [Bug rtl-optimization/29978] " vda dot linux at googlemail dot com
2007-12-14 11:05 ` [Bug rtl-optimization/29978] [4.0/4.1/4.2/4.3 Regression] redundant jumps aldot at gcc dot gnu dot org
2007-12-14 11:24 ` aldot at gcc dot gnu dot org
2007-12-14 11:32 ` [Bug target/29978] " pinskia at gcc dot gnu dot org
2007-12-14 13:04 ` jakub at gcc dot gnu dot org
2007-12-14 18:01 ` jakub at gcc dot gnu dot org
2007-12-14 18:31 ` [Bug target/29978] [4.0/4.1/4.2 " jakub at gcc dot gnu dot org
2008-07-04 21:45 ` [Bug target/29978] [4.2 " jsm28 at gcc dot gnu dot org
2009-03-30 19:43 ` jsm28 at gcc dot gnu dot 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).