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* [Bug tree-optimization/19624] New: PRE pessimizes ivopts
@ 2005-01-25 14:45 rguenth at tat dot physik dot uni-tuebingen dot de
2005-01-25 14:45 ` [Bug tree-optimization/19624] " rguenth at tat dot physik dot uni-tuebingen dot de
` (8 more replies)
0 siblings, 9 replies; 10+ messages in thread
From: rguenth at tat dot physik dot uni-tuebingen dot de @ 2005-01-25 14:45 UTC (permalink / raw)
To: gcc-bugs
The attached testcase is pessimized by PRE. Be sure to get tree-level complete
loop unrolling enabled, f.i. with -O2 -funroll-loops with current mainline.
With PRE, a lot less computations are hoisted out of the inner loop. Note this
is not a regression to 3.4, which is not able to decompose Loc<Dim> appropriately
or avoid instantiating temporary objects of this type.
--
Summary: PRE pessimizes ivopts
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: rguenth at tat dot physik dot uni-tuebingen dot de
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19624
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/19624] PRE pessimizes ivopts
2005-01-25 14:45 [Bug tree-optimization/19624] New: PRE pessimizes ivopts rguenth at tat dot physik dot uni-tuebingen dot de
@ 2005-01-25 14:45 ` rguenth at tat dot physik dot uni-tuebingen dot de
2005-01-25 14:52 ` rguenth at tat dot physik dot uni-tuebingen dot de
` (7 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: rguenth at tat dot physik dot uni-tuebingen dot de @ 2005-01-25 14:45 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From rguenth at tat dot physik dot uni-tuebingen dot de 2005-01-25 14:45 -------
Created an attachment (id=8060)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=8060&action=view)
testcase
The testcase is reduced from a complex POOMA program.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19624
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/19624] PRE pessimizes ivopts
2005-01-25 14:45 [Bug tree-optimization/19624] New: PRE pessimizes ivopts rguenth at tat dot physik dot uni-tuebingen dot de
2005-01-25 14:45 ` [Bug tree-optimization/19624] " rguenth at tat dot physik dot uni-tuebingen dot de
@ 2005-01-25 14:52 ` rguenth at tat dot physik dot uni-tuebingen dot de
2005-01-25 15:23 ` dberlin at gcc dot gnu dot org
` (6 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: rguenth at tat dot physik dot uni-tuebingen dot de @ 2005-01-25 14:52 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From rguenth at tat dot physik dot uni-tuebingen dot de 2005-01-25 14:52 -------
Oh, in principle this should compile to roughly the same as
void c_test(double *a, double *b, int ei, int ej, int stridea, int strideb)
{
for (int j=0; j<ej; ++j)
for (int i=0; i<ei; ++i)
a[i+j*stridea] = 0.5*(b[i+1+j*strideb] + b[i+(j+1)*strideb]);
}
... in principle (for the above -fno-tree-pre helps, too).
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19624
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/19624] PRE pessimizes ivopts
2005-01-25 14:45 [Bug tree-optimization/19624] New: PRE pessimizes ivopts rguenth at tat dot physik dot uni-tuebingen dot de
2005-01-25 14:45 ` [Bug tree-optimization/19624] " rguenth at tat dot physik dot uni-tuebingen dot de
2005-01-25 14:52 ` rguenth at tat dot physik dot uni-tuebingen dot de
@ 2005-01-25 15:23 ` dberlin at gcc dot gnu dot org
2005-01-25 15:27 ` rguenth at tat dot physik dot uni-tuebingen dot de
` (5 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: dberlin at gcc dot gnu dot org @ 2005-01-25 15:23 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From dberlin at gcc dot gnu dot org 2005-01-25 15:23 -------
Just as an FYI, i have absoutely no plans to make it so ivopts and PRE interact
perfectly.
I only plan to disable transforms in PRE that are always unprofitable.
--
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|unassigned at gcc dot gnu |dberlin at gcc dot gnu dot
|dot org |org
Status|UNCONFIRMED |ASSIGNED
Ever Confirmed| |1
Last reconfirmed|0000-00-00 00:00:00 |2005-01-25 15:23:01
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19624
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/19624] PRE pessimizes ivopts
2005-01-25 14:45 [Bug tree-optimization/19624] New: PRE pessimizes ivopts rguenth at tat dot physik dot uni-tuebingen dot de
` (2 preceding siblings ...)
2005-01-25 15:23 ` dberlin at gcc dot gnu dot org
@ 2005-01-25 15:27 ` rguenth at tat dot physik dot uni-tuebingen dot de
2005-01-25 15:35 ` dberlin at dberlin dot org
` (4 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: rguenth at tat dot physik dot uni-tuebingen dot de @ 2005-01-25 15:27 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From rguenth at tat dot physik dot uni-tuebingen dot de 2005-01-25 15:27 -------
I guess making PRE and ivopts playing nicely together perfectly is near to
impossible - but any improvement in the 4.0 timeframe is welcome!
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19624
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/19624] PRE pessimizes ivopts
2005-01-25 14:45 [Bug tree-optimization/19624] New: PRE pessimizes ivopts rguenth at tat dot physik dot uni-tuebingen dot de
` (3 preceding siblings ...)
2005-01-25 15:27 ` rguenth at tat dot physik dot uni-tuebingen dot de
@ 2005-01-25 15:35 ` dberlin at dberlin dot org
2005-01-30 19:09 ` dberlin at gcc dot gnu dot org
` (3 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: dberlin at dberlin dot org @ 2005-01-25 15:35 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From dberlin at gcc dot gnu dot org 2005-01-25 15:35 -------
Subject: Re: PRE pessimizes ivopts
On Tue, 2005-01-25 at 15:27 +0000, rguenth at tat dot physik dot
uni-tuebingen dot de wrote:
> ------- Additional Comments From rguenth at tat dot physik dot uni-tuebingen dot de 2005-01-25 15:27 -------
> I guess making PRE and ivopts playing nicely together perfectly is near to
> impossible
Yes, hence why i don't plan on promising it :)
There are always optimization interactions that are very very hard to
control or predict.
The best you can do is not make your optimization do things that are
always unprofitable, try to make them interact better where possible,
and hope for the best.
> - but any improvement in the 4.0 timeframe is welcome!
>
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19624
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/19624] PRE pessimizes ivopts
2005-01-25 14:45 [Bug tree-optimization/19624] New: PRE pessimizes ivopts rguenth at tat dot physik dot uni-tuebingen dot de
` (4 preceding siblings ...)
2005-01-25 15:35 ` dberlin at dberlin dot org
@ 2005-01-30 19:09 ` dberlin at gcc dot gnu dot org
2005-01-30 19:09 ` cvs-commit at gcc dot gnu dot org
` (2 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: dberlin at gcc dot gnu dot org @ 2005-01-30 19:09 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From dberlin at gcc dot gnu dot org 2005-01-30 19:08 -------
El Fixed
--
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution| |FIXED
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19624
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/19624] PRE pessimizes ivopts
2005-01-25 14:45 [Bug tree-optimization/19624] New: PRE pessimizes ivopts rguenth at tat dot physik dot uni-tuebingen dot de
` (5 preceding siblings ...)
2005-01-30 19:09 ` dberlin at gcc dot gnu dot org
@ 2005-01-30 19:09 ` cvs-commit at gcc dot gnu dot org
2005-01-30 19:10 ` pinskia at gcc dot gnu dot org
2005-01-30 20:56 ` steven at gcc dot gnu dot org
8 siblings, 0 replies; 10+ messages in thread
From: cvs-commit at gcc dot gnu dot org @ 2005-01-30 19:09 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From cvs-commit at gcc dot gnu dot org 2005-01-30 19:09 -------
Subject: Bug 19624
CVSROOT: /cvs/gcc
Module name: gcc
Changes by: dberlin@gcc.gnu.org 2005-01-30 19:08:37
Modified files:
gcc : Makefile.in tree-ssa-pre.c
Added files:
gcc/testsuite/gcc.dg/tree-ssa: ssa-pre-4.c ssa-pre-5.c
ssa-pre-6.c
Log message:
2005-01-30 Daniel Berlin <dberlin@dberlin.org>
Fix PR tree-optimization/19624
* Makefile.in (tree-ssa-pre.o): Add CFGLOOP_H.
* tree-ssa-pre.c: Add cfgloop.h.
Update comment.
(pre_stats): New member, constified.
(inserted_exprs): New static variable.
(NECESSARY): New macro.
(create_expression_by_pieces): Fold the expression, and
mark it as defaulting to not necessary. Also put in
inserted_exprs.
(fully_constant_expression): New function.
(insert_into_preds_of_block): Modify to not insert phis when we
are playing with induction variables.
Push phis onto the inserted_exprs vector, and mark them as not
necessary by default.
(insert_aux): Call fully_constant_expression on eprime.
If all edges produce the same value, mark it constant.
(mark_operand_necessary): New function.
(remove_dead_inserted_code): New function.
(init_pre): Init loop optimizer to get loop info.
(fini_pre): Free loop_optimizer, and inserted_exprs vec.
(execute_pre): Commit edge inserts, then remove dead code.
Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/Makefile.in.diff?cvsroot=gcc&r1=1.1444&r2=1.1445
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-ssa-pre.c.diff?cvsroot=gcc&r1=2.62&r2=2.63
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-4.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-5.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-6.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19624
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/19624] PRE pessimizes ivopts
2005-01-25 14:45 [Bug tree-optimization/19624] New: PRE pessimizes ivopts rguenth at tat dot physik dot uni-tuebingen dot de
` (6 preceding siblings ...)
2005-01-30 19:09 ` cvs-commit at gcc dot gnu dot org
@ 2005-01-30 19:10 ` pinskia at gcc dot gnu dot org
2005-01-30 20:56 ` steven at gcc dot gnu dot org
8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-01-30 19:10 UTC (permalink / raw)
To: gcc-bugs
--
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |missed-optimization
Target Milestone|--- |4.0.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19624
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/19624] PRE pessimizes ivopts
2005-01-25 14:45 [Bug tree-optimization/19624] New: PRE pessimizes ivopts rguenth at tat dot physik dot uni-tuebingen dot de
` (7 preceding siblings ...)
2005-01-30 19:10 ` pinskia at gcc dot gnu dot org
@ 2005-01-30 20:56 ` steven at gcc dot gnu dot org
8 siblings, 0 replies; 10+ messages in thread
From: steven at gcc dot gnu dot org @ 2005-01-30 20:56 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From steven at gcc dot gnu dot org 2005-01-30 20:56 -------
This pach doesn't have a ChangeLog.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19624
^ permalink raw reply [flat|nested] 10+ messages in thread
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2005-01-25 14:45 [Bug tree-optimization/19624] New: PRE pessimizes ivopts rguenth at tat dot physik dot uni-tuebingen dot de
2005-01-25 14:45 ` [Bug tree-optimization/19624] " rguenth at tat dot physik dot uni-tuebingen dot de
2005-01-25 14:52 ` rguenth at tat dot physik dot uni-tuebingen dot de
2005-01-25 15:23 ` dberlin at gcc dot gnu dot org
2005-01-25 15:27 ` rguenth at tat dot physik dot uni-tuebingen dot de
2005-01-25 15:35 ` dberlin at dberlin dot org
2005-01-30 19:09 ` dberlin at gcc dot gnu dot org
2005-01-30 19:09 ` cvs-commit at gcc dot gnu dot org
2005-01-30 19:10 ` pinskia at gcc dot gnu dot org
2005-01-30 20:56 ` steven at gcc dot gnu dot org
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