* [Bug optimization/12771] Weak loop optimizer, significant performance regression
2003-10-25 0:54 [Bug optimization/12771] New: Weak loop optimizer, significant performance regression tm at kloo dot net
@ 2003-10-25 1:03 ` tm at kloo dot net
2003-10-25 1:31 ` pinskia at gcc dot gnu dot org
` (6 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: tm at kloo dot net @ 2003-10-25 1:03 UTC (permalink / raw)
To: gcc-bugs
PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12771
------- Additional Comments From tm at kloo dot net 2003-10-25 00:55 -------
Created an attachment (id=4992)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=4992&action=view)
preprocessed source for linpack
preprocessed source for linpack for this PR
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug optimization/12771] Weak loop optimizer, significant performance regression
2003-10-25 0:54 [Bug optimization/12771] New: Weak loop optimizer, significant performance regression tm at kloo dot net
2003-10-25 1:03 ` [Bug optimization/12771] " tm at kloo dot net
@ 2003-10-25 1:31 ` pinskia at gcc dot gnu dot org
2003-10-27 11:33 ` tm at kloo dot net
` (5 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2003-10-25 1:31 UTC (permalink / raw)
To: gcc-bugs
PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12771
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |pessimizes-code
------- Additional Comments From pinskia at gcc dot gnu dot org 2003-10-25 01:14 -------
What is this a regression from, I get about the same code from 2.95.3, 3.2.3, and 3.3.1?
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug optimization/12771] Weak loop optimizer, significant performance regression
2003-10-25 0:54 [Bug optimization/12771] New: Weak loop optimizer, significant performance regression tm at kloo dot net
2003-10-25 1:03 ` [Bug optimization/12771] " tm at kloo dot net
2003-10-25 1:31 ` pinskia at gcc dot gnu dot org
@ 2003-10-27 11:33 ` tm at kloo dot net
2003-10-28 15:42 ` [Bug optimization/12771] Weak loop optimizer pinskia at gcc dot gnu dot org
` (4 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: tm at kloo dot net @ 2003-10-27 11:33 UTC (permalink / raw)
To: gcc-bugs
PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12771
------- Additional Comments From tm at kloo dot net 2003-10-27 10:01 -------
Subject: Re: Weak loop optimizer, significant
performance regression
On 25 Oct 2003, pinskia at gcc dot gnu dot org wrote:
Regression from 2.7.2.
Toshi
> PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12771
>
>
> pinskia at gcc dot gnu dot org changed:
>
> What |Removed |Added
> ----------------------------------------------------------------------------
> Keywords| |pessimizes-code
>
>
> ------- Additional Comments From pinskia at gcc dot gnu dot org 2003-10-25 01:14 -------
> What is this a regression from, I get about the same code from 2.95.3, 3.2.3, and 3.3.1?
>
>
>
>
> ------- You are receiving this mail because: -------
> You reported the bug, or are watching the reporter.
>
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug optimization/12771] Weak loop optimizer
2003-10-25 0:54 [Bug optimization/12771] New: Weak loop optimizer, significant performance regression tm at kloo dot net
` (2 preceding siblings ...)
2003-10-27 11:33 ` tm at kloo dot net
@ 2003-10-28 15:42 ` pinskia at gcc dot gnu dot org
2003-10-28 19:22 ` tm at kloo dot net
` (3 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2003-10-28 15:42 UTC (permalink / raw)
To: gcc-bugs
PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12771
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Severity|normal |enhancement
Status|UNCONFIRMED |NEW
Ever Confirmed| |1
Last reconfirmed|0000-00-00 00:00:00 |2003-10-28 15:38:57
date| |
Summary|Weak loop optimizer, |Weak loop optimizer
|significant performance |
|regression |
------- Additional Comments From pinskia at gcc dot gnu dot org 2003-10-28 15:38 -------
Since this is a regression from 2.7.2 which was released November 26, 1995 almost 8 years ago,
we cannot really count this one as a regression as so much has changed since then.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug optimization/12771] Weak loop optimizer
2003-10-25 0:54 [Bug optimization/12771] New: Weak loop optimizer, significant performance regression tm at kloo dot net
` (3 preceding siblings ...)
2003-10-28 15:42 ` [Bug optimization/12771] Weak loop optimizer pinskia at gcc dot gnu dot org
@ 2003-10-28 19:22 ` tm at kloo dot net
2004-03-07 1:34 ` pinskia at gcc dot gnu dot org
` (2 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: tm at kloo dot net @ 2003-10-28 19:22 UTC (permalink / raw)
To: gcc-bugs
PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12771
------- Additional Comments From tm at kloo dot net 2003-10-28 19:21 -------
Subject: Re: Weak loop optimizer
On 28 Oct 2003, pinskia at gcc dot gnu dot org wrote:
It's still an optimization weakness.
Toshi
> PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12771
>
>
> pinskia at gcc dot gnu dot org changed:
>
> What |Removed |Added
> ----------------------------------------------------------------------------
> Severity|normal |enhancement
> Status|UNCONFIRMED |NEW
> Ever Confirmed| |1
> Last reconfirmed|0000-00-00 00:00:00 |2003-10-28 15:38:57
> date| |
> Summary|Weak loop optimizer, |Weak loop optimizer
> |significant performance |
> |regression |
>
>
> ------- Additional Comments From pinskia at gcc dot gnu dot org 2003-10-28 15:38 -------
> Since this is a regression from 2.7.2 which was released November 26, 1995 almost 8 years ago,
> we cannot really count this one as a regression as so much has changed since then.
>
>
>
> ------- You are receiving this mail because: -------
> You reported the bug, or are watching the reporter.
>
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug optimization/12771] Weak loop optimizer
2003-10-25 0:54 [Bug optimization/12771] New: Weak loop optimizer, significant performance regression tm at kloo dot net
` (4 preceding siblings ...)
2003-10-28 19:22 ` tm at kloo dot net
@ 2004-03-07 1:34 ` pinskia at gcc dot gnu dot org
2005-03-23 3:07 ` [Bug rtl-optimization/12771] " pinskia at gcc dot gnu dot org
2005-05-07 20:47 ` pinskia at gcc dot gnu dot org
7 siblings, 0 replies; 9+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-03-07 1:34 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-03-07 01:34 -------
The mainline has changed but still the same number of memory accesses:
movl 16(%ebp), %edx
flds (%edx,%eax,4)
fmul %st(1), %st
fadds (%esi,%eax,4)
fstps (%esi,%eax,4)
incl %eax
On the other hand with -freduce-all-givs, it has increased by one:
.L15:
flds (%ecx)
addl $4, %ecx
fmul %st(1), %st
fadds (%eax)
fstps (%eax)
addl $4, %eax
decl %edx
jne .L15
Here is the reduced source:
void daxpy(int n, float da, float dx[], int incx, float dy[], int incy)
{
int i,ix,iy,m,mp1;
mp1 = 0;
m = 0;
if(n <= 0) return;
if (da == 0.0 ) return;
if(incx != 1 || incy != 1) {
ix = 0;
iy = 0;
if(incx < 0) ix = (-n+1)*incx;
if(incy < 0)iy = (-n+1)*incy;
for (i = 0;i < n; i++) {
dy[iy] = dy[iy] + da*dx[ix];
ix = ix + incx;
iy = iy + incy;
}
return;
}
for (i = 0;i < n; i++) {
dy[i] = dy[i] + da*dx[i];
}
return;
}
--
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed|2003-10-28 15:38:57 |2004-03-07 01:34:09
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12771
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug rtl-optimization/12771] Weak loop optimizer
2003-10-25 0:54 [Bug optimization/12771] New: Weak loop optimizer, significant performance regression tm at kloo dot net
` (5 preceding siblings ...)
2004-03-07 1:34 ` pinskia at gcc dot gnu dot org
@ 2005-03-23 3:07 ` pinskia at gcc dot gnu dot org
2005-05-07 20:47 ` pinskia at gcc dot gnu dot org
7 siblings, 0 replies; 9+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-03-23 3:07 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-03-23 03:07 -------
We are better on the mainline but still not as good with the old code with -freduce-all-givs.
Here is what we get with the mainline:
.L14:
fld %st(0)
fmuls (%ecx,%edx,4)
incl %edx
fadds (%eax)
fstps (%eax)
addl $4, %eax
cmpl %edx, %esi
jne .L14
--
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed|2004-12-22 04:37:34 |2005-03-23 03:07:20
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12771
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug rtl-optimization/12771] Weak loop optimizer
2003-10-25 0:54 [Bug optimization/12771] New: Weak loop optimizer, significant performance regression tm at kloo dot net
` (6 preceding siblings ...)
2005-03-23 3:07 ` [Bug rtl-optimization/12771] " pinskia at gcc dot gnu dot org
@ 2005-05-07 20:47 ` pinskia at gcc dot gnu dot org
7 siblings, 0 replies; 9+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-05-07 20:47 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-05-07 20:47 -------
On the mainline, we get:
.L13:
fld %st(0)
incl %ecx
fmuls (%edx)
addl %ebx, %edx
fadds (%eax)
fstps (%eax)
addl %esi, %eax
cmpl %ecx, %edi
jne .L13
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12771
^ permalink raw reply [flat|nested] 9+ messages in thread