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* [Bug target/21715] [4.0/4.1 regression] code-generation performance regression
[not found] <bug-21715-4672@http.gcc.gnu.org/bugzilla/>
@ 2005-10-22 3:07 ` pinskia at gcc dot gnu dot org
2005-10-31 3:40 ` mmitchel at gcc dot gnu dot org
` (8 subsequent siblings)
9 siblings, 0 replies; 14+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-10-22 3:07 UTC (permalink / raw)
To: gcc-bugs
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Severity|normal |minor
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21715
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug target/21715] [4.0/4.1 regression] code-generation performance regression
[not found] <bug-21715-4672@http.gcc.gnu.org/bugzilla/>
2005-10-22 3:07 ` [Bug target/21715] [4.0/4.1 regression] code-generation performance regression pinskia at gcc dot gnu dot org
@ 2005-10-31 3:40 ` mmitchel at gcc dot gnu dot org
2005-11-06 16:35 ` pinskia at gcc dot gnu dot org
` (7 subsequent siblings)
9 siblings, 0 replies; 14+ messages in thread
From: mmitchel at gcc dot gnu dot org @ 2005-10-31 3:40 UTC (permalink / raw)
To: gcc-bugs
------- Comment #4 from mmitchel at gcc dot gnu dot org 2005-10-31 03:40 -------
Leaving as P2.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21715
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug target/21715] [4.0/4.1 regression] code-generation performance regression
[not found] <bug-21715-4672@http.gcc.gnu.org/bugzilla/>
2005-10-22 3:07 ` [Bug target/21715] [4.0/4.1 regression] code-generation performance regression pinskia at gcc dot gnu dot org
2005-10-31 3:40 ` mmitchel at gcc dot gnu dot org
@ 2005-11-06 16:35 ` pinskia at gcc dot gnu dot org
2005-12-19 2:30 ` kazu at gcc dot gnu dot org
` (6 subsequent siblings)
9 siblings, 0 replies; 14+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-11-06 16:35 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from pinskia at gcc dot gnu dot org 2005-11-06 16:35 -------
I am starting to think what 3.4.x did was just an accident that it got it right
in the first place.
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to fail|4.0.0 4.1.0 3.3.5 |4.0.0 4.1.0 3.3.5 3.3.6
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21715
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug target/21715] [4.0/4.1 regression] code-generation performance regression
[not found] <bug-21715-4672@http.gcc.gnu.org/bugzilla/>
` (2 preceding siblings ...)
2005-11-06 16:35 ` pinskia at gcc dot gnu dot org
@ 2005-12-19 2:30 ` kazu at gcc dot gnu dot org
2006-01-07 18:42 ` steven at gcc dot gnu dot org
` (5 subsequent siblings)
9 siblings, 0 replies; 14+ messages in thread
From: kazu at gcc dot gnu dot org @ 2005-12-19 2:30 UTC (permalink / raw)
To: gcc-bugs
------- Comment #6 from kazu at gcc dot gnu dot org 2005-12-19 02:30 -------
I just compiled the testcase on x86_64. I got
foo:
.LFB2:
movq %rdi, %rax
negq %rax
andq %rdi, %rax
ret
which is as good as the assembly generated by 3.4.3.
This is no longer a regression on 4.2.
--
kazu at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |kazu at gcc dot gnu dot org
Known to work|3.4.3 |3.4.3 4.2.0
Summary|[4.0/4.1/4.2 regression] |[4.0/4.1 regression] code-
|code-generation performance |generation performance
|regression |regression
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21715
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug target/21715] [4.0/4.1 regression] code-generation performance regression
[not found] <bug-21715-4672@http.gcc.gnu.org/bugzilla/>
` (3 preceding siblings ...)
2005-12-19 2:30 ` kazu at gcc dot gnu dot org
@ 2006-01-07 18:42 ` steven at gcc dot gnu dot org
2006-01-10 17:50 ` steven at gcc dot gnu dot org
` (4 subsequent siblings)
9 siblings, 0 replies; 14+ messages in thread
From: steven at gcc dot gnu dot org @ 2006-01-07 18:42 UTC (permalink / raw)
To: gcc-bugs
------- Comment #7 from steven at gcc dot gnu dot org 2006-01-07 18:41 -------
GCC 4.1-20060107 still produces the code reported in the original bug report:
0000000000000000 <foo>:
0: 48 89 f8 mov %rdi,%rax
3: 48 f7 d8 neg %rax
6: 48 21 c7 and %rax,%rdi
9: 48 89 f8 mov %rdi,%rax
c: c3 retq
What patch may have fixed this on the trunk?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21715
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug target/21715] [4.0/4.1 regression] code-generation performance regression
[not found] <bug-21715-4672@http.gcc.gnu.org/bugzilla/>
` (4 preceding siblings ...)
2006-01-07 18:42 ` steven at gcc dot gnu dot org
@ 2006-01-10 17:50 ` steven at gcc dot gnu dot org
2006-02-24 0:30 ` mmitchel at gcc dot gnu dot org
` (3 subsequent siblings)
9 siblings, 0 replies; 14+ messages in thread
From: steven at gcc dot gnu dot org @ 2006-01-10 17:50 UTC (permalink / raw)
To: gcc-bugs
------- Comment #8 from steven at gcc dot gnu dot org 2006-01-10 17:50 -------
The new reassociation pass, or the removal of DOM's reassociation bits, fixed
this on the trunk. We get poorer initial RTL generation out of GCC 4.1 and we
never manage to fix it up:
The .final_cleanup from GCC 4.1 and GCC 4.0:
;; Function foo (foo)
foo (v)
{
<bb 0>:
return v & -v;
}
And the .final_cleanup from GCC 4.2:
;; Function foo (foo)
foo (v)
{
<bb 2>:
return -v & v;
}
(insn 12 11 13 (parallel [
(set (reg:DI 60)
- (and:DI (reg/v:DI 59 [ v ])
- (reg:DI 61)))
+ (and:DI (reg:DI 61)
+ (reg/v:DI 59 [ v ])))
(clobber (reg:CC 17 flags))
]) -1 (nil)
(nil))
So this regression is not caused by the register allocator, but it does play a
role:
In the .combine and .ce2 RTL dumps, the difference is still there:
(insn 12 11 16 (parallel [
(insn 12 11 16 (parallel [
(set (reg:DI 60)
- (and:DI (reg/v:DI 59 [ v ])
- (reg:DI 61)))
+ (and:DI (reg:DI 61)
+ (reg/v:DI 59 [ v ])))
(clobber (reg:CC 17 flags))
- (expr_list:REG_DEAD (reg/v:DI 59 [ v ])
- (expr_list:REG_DEAD (reg:DI 61)
+ (expr_list:REG_DEAD (reg:DI 61)
+ (expr_list:REG_DEAD (reg/v:DI 59 [ v ])
(expr_list:REG_UNUSED (reg:CC 17 flags)
(nil)))))
Then in the .regmove RTL dump something changes:
(insn:HI 12 11 16 (parallel [
- (set (reg/v:DI 59 [ v ])
- (and:DI (reg/v:DI 59 [ v ])
- (reg:DI 61)))
+ (set (reg:DI 61)
+ (and:DI (reg:DI 61)
+ (reg/v:DI 59 [ v ])))
(clobber (reg:CC 17 flags))
]) 297 {*anddi_1_rex64} (insn_list:REG_DEP_TRUE 11 (nil))
- (expr_list:REG_DEAD (reg:DI 61)
+ (expr_list:REG_DEAD (reg/v:DI 59 [ v ])
(expr_list:REG_UNUSED (reg:CC 17 flags)
(nil))))
This small difference eventually leads to a different choice of register
allocation. The choice that GCC 4.2 makes is superior because it makes the
move to the result a dead instruction. The .greg RTL dump shows this:
-(insn:HI 12 11 16 0 (parallel [
- (set (reg/v:DI 5 di [orig:59 v ] [59])
- (and:DI (reg/v:DI 5 di [orig:59 v ] [59])
- (reg:DI 0 ax [61])))
+(insn:HI 12 11 16 2 (parallel [
+ (set (reg:DI 0 ax [61])
+ (and:DI (reg:DI 0 ax [61])
+ (reg/v:DI 5 di [orig:59 v ] [59])))
(clobber (reg:CC 17 flags))
]) 297 {*anddi_1_rex64} (insn_list:REG_DEP_TRUE 11 (nil))
(nil))
-(insn:HI 19 16 25 0 (set (reg/i:DI 0 ax [ <result> ])
- (reg/v:DI 5 di [orig:59 v ] [59])) 81 {*movdi_1_rex64}
- (insn_list:REG_DEP_TRUE 12 (nil))
- (nil))
--
steven at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
BugsThisDependsOn|18427 |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21715
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug target/21715] [4.0/4.1 regression] code-generation performance regression
[not found] <bug-21715-4672@http.gcc.gnu.org/bugzilla/>
` (5 preceding siblings ...)
2006-01-10 17:50 ` steven at gcc dot gnu dot org
@ 2006-02-24 0:30 ` mmitchel at gcc dot gnu dot org
2006-05-25 2:43 ` mmitchel at gcc dot gnu dot org
` (2 subsequent siblings)
9 siblings, 0 replies; 14+ messages in thread
From: mmitchel at gcc dot gnu dot org @ 2006-02-24 0:30 UTC (permalink / raw)
To: gcc-bugs
------- Comment #9 from mmitchel at gcc dot gnu dot org 2006-02-24 00:25 -------
This issue will not be resolved in GCC 4.1.0; retargeted at GCC 4.1.1.
--
mmitchel at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.0.3 |4.1.1
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21715
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug target/21715] [4.0/4.1 regression] code-generation performance regression
[not found] <bug-21715-4672@http.gcc.gnu.org/bugzilla/>
` (6 preceding siblings ...)
2006-02-24 0:30 ` mmitchel at gcc dot gnu dot org
@ 2006-05-25 2:43 ` mmitchel at gcc dot gnu dot org
2007-02-14 9:13 ` mmitchel at gcc dot gnu dot org
2008-02-20 22:36 ` rguenth at gcc dot gnu dot org
9 siblings, 0 replies; 14+ messages in thread
From: mmitchel at gcc dot gnu dot org @ 2006-05-25 2:43 UTC (permalink / raw)
To: gcc-bugs
------- Comment #10 from mmitchel at gcc dot gnu dot org 2006-05-25 02:33 -------
Will not be fixed in 4.1.1; adjust target milestone to 4.1.2.
--
mmitchel at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.1.1 |4.1.2
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21715
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug target/21715] [4.0/4.1 regression] code-generation performance regression
[not found] <bug-21715-4672@http.gcc.gnu.org/bugzilla/>
` (7 preceding siblings ...)
2006-05-25 2:43 ` mmitchel at gcc dot gnu dot org
@ 2007-02-14 9:13 ` mmitchel at gcc dot gnu dot org
2008-02-20 22:36 ` rguenth at gcc dot gnu dot org
9 siblings, 0 replies; 14+ messages in thread
From: mmitchel at gcc dot gnu dot org @ 2007-02-14 9:13 UTC (permalink / raw)
To: gcc-bugs
--
mmitchel at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.1.2 |4.1.3
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21715
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug target/21715] [4.0/4.1 regression] code-generation performance regression
[not found] <bug-21715-4672@http.gcc.gnu.org/bugzilla/>
` (8 preceding siblings ...)
2007-02-14 9:13 ` mmitchel at gcc dot gnu dot org
@ 2008-02-20 22:36 ` rguenth at gcc dot gnu dot org
9 siblings, 0 replies; 14+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2008-02-20 22:36 UTC (permalink / raw)
To: gcc-bugs
------- Comment #11 from rguenth at gcc dot gnu dot org 2008-02-20 22:35 -------
Fixed since 4.2.0, wontfix on older branches.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Known to fail|4.0.0 4.1.0 3.3.5 3.3.6 |4.0.0 4.1.0 4.1.3 3.3.5
| |3.3.6
Resolution| |FIXED
Target Milestone|4.1.3 |4.2.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21715
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug target/21715] [4.0/4.1 regression] code-generation performance regression
2005-05-23 8:25 [Bug target/21715] New: code-generation regression markus at oberhumer dot com
` (2 preceding siblings ...)
2005-09-16 19:04 ` pinskia at gcc dot gnu dot org
@ 2005-09-27 16:07 ` mmitchel at gcc dot gnu dot org
3 siblings, 0 replies; 14+ messages in thread
From: mmitchel at gcc dot gnu dot org @ 2005-09-27 16:07 UTC (permalink / raw)
To: gcc-bugs
--
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.0.2 |4.0.3
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21715
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug target/21715] [4.0/4.1 regression] code-generation performance regression
2005-05-23 8:25 [Bug target/21715] New: code-generation regression markus at oberhumer dot com
2005-05-23 18:22 ` [Bug target/21715] [4.0/4.1 regression] code-generation performance regression pinskia at gcc dot gnu dot org
2005-07-08 1:40 ` mmitchel at gcc dot gnu dot org
@ 2005-09-16 19:04 ` pinskia at gcc dot gnu dot org
2005-09-27 16:07 ` mmitchel at gcc dot gnu dot org
3 siblings, 0 replies; 14+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-09-16 19:04 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-09-16 19:04 -------
3.3.5 also fails. I think this is also related to the message on the gcc mailing list recently:
http://gcc.gnu.org/ml/gcc/2005-09/msg00429.html
This is looks related to 2 operand targets.
--
What |Removed |Added
----------------------------------------------------------------------------
Known to fail|4.0.0 4.1.0 |4.0.0 4.1.0 3.3.5
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21715
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug target/21715] [4.0/4.1 regression] code-generation performance regression
2005-05-23 8:25 [Bug target/21715] New: code-generation regression markus at oberhumer dot com
2005-05-23 18:22 ` [Bug target/21715] [4.0/4.1 regression] code-generation performance regression pinskia at gcc dot gnu dot org
@ 2005-07-08 1:40 ` mmitchel at gcc dot gnu dot org
2005-09-16 19:04 ` pinskia at gcc dot gnu dot org
2005-09-27 16:07 ` mmitchel at gcc dot gnu dot org
3 siblings, 0 replies; 14+ messages in thread
From: mmitchel at gcc dot gnu dot org @ 2005-07-08 1:40 UTC (permalink / raw)
To: gcc-bugs
--
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.0.1 |4.0.2
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21715
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug target/21715] [4.0/4.1 regression] code-generation performance regression
2005-05-23 8:25 [Bug target/21715] New: code-generation regression markus at oberhumer dot com
@ 2005-05-23 18:22 ` pinskia at gcc dot gnu dot org
2005-07-08 1:40 ` mmitchel at gcc dot gnu dot org
` (2 subsequent siblings)
3 siblings, 0 replies; 14+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-05-23 18:22 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-05-23 18:17 -------
Confirmed.
This is just a RA issue, I don't know how much we can fix for 4.0.x.
--
What |Removed |Added
----------------------------------------------------------------------------
BugsThisDependsOn| |18427
Status|UNCONFIRMED |NEW
Ever Confirmed| |1
Last reconfirmed|0000-00-00 00:00:00 |2005-05-23 18:17:00
date| |
Summary|code-generation performance |[4.0/4.1 regression] code-
|regression |generation performance
| |regression
Target Milestone|--- |4.0.1
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21715
^ permalink raw reply [flat|nested] 14+ messages in thread
end of thread, other threads:[~2008-02-20 22:36 UTC | newest]
Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
[not found] <bug-21715-4672@http.gcc.gnu.org/bugzilla/>
2005-10-22 3:07 ` [Bug target/21715] [4.0/4.1 regression] code-generation performance regression pinskia at gcc dot gnu dot org
2005-10-31 3:40 ` mmitchel at gcc dot gnu dot org
2005-11-06 16:35 ` pinskia at gcc dot gnu dot org
2005-12-19 2:30 ` kazu at gcc dot gnu dot org
2006-01-07 18:42 ` steven at gcc dot gnu dot org
2006-01-10 17:50 ` steven at gcc dot gnu dot org
2006-02-24 0:30 ` mmitchel at gcc dot gnu dot org
2006-05-25 2:43 ` mmitchel at gcc dot gnu dot org
2007-02-14 9:13 ` mmitchel at gcc dot gnu dot org
2008-02-20 22:36 ` rguenth at gcc dot gnu dot org
2005-05-23 8:25 [Bug target/21715] New: code-generation regression markus at oberhumer dot com
2005-05-23 18:22 ` [Bug target/21715] [4.0/4.1 regression] code-generation performance regression pinskia at gcc dot gnu dot org
2005-07-08 1:40 ` mmitchel at gcc dot gnu dot org
2005-09-16 19:04 ` pinskia at gcc dot gnu dot org
2005-09-27 16:07 ` mmitchel at gcc dot gnu dot org
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