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* [Bug tree-optimization/18400] New: wrong unrolling after vectorization due to invalid loop->nb_iterations
@ 2004-11-09 14:50 dorit at il dot ibm dot com
2004-11-09 14:54 ` [Bug tree-optimization/18400] " dorit at il dot ibm dot com
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: dorit at il dot ibm dot com @ 2004-11-09 14:50 UTC (permalink / raw)
To: gcc-bugs
When a loop like the following:
=============================
#define N 8
int main ()
{
int b[N] = {0,3,6,9,12,15,18,21};
int a[N];
int i;
for (i = 0; i < N; i++){
a[i] = b[i];
}
/* check results: */
for (i = 0; i < N; i++){
if (a[i] != b[i])
abort ();
}
return 0;
}
=============================
is compiled with:
-O2 -ftree-vectorize -maltivec -funroll-loops
it gets vectorized and then completely unrolled. The complete unroller looks at
loop->nb_iterations to get the number of iterations; the problem is that loop-
>nb_iterations is not always updated after vectorization, so the loop ends up
being unrolled by 8 instead of by 2, and we get an execution failure.
The following patch will fix the problem:
Index: tree-vectorizer.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-vectorizer.c,v
retrieving revision 2.25
diff -c -3 -p -r2.25 tree-vectorizer.c
*** tree-vectorizer.c 8 Nov 2004 13:54:41 -0000 2.25
--- tree-vectorizer.c 9 Nov 2004 13:16:54 -0000
*************** make_loop_iterate_ntimes (struct loop *l
*** 635,640 ****
--- 635,642 ----
if (vect_debug_stats (loop) || vect_debug_details (loop))
print_generic_expr (dump_file, cond_stmt, TDF_SLIM);
+
+ loop->nb_iterations = niters;
}
*************** vect_transform_loop_bound (loop_vec_info
*** 2881,2886 ****
--- 2883,2890 ----
if (vect_debug_details (NULL))
print_generic_expr (dump_file, cond_stmt, TDF_SLIM);
+
+ loop->nb_iterations = new_loop_bound;
}
--
Summary: wrong unrolling after vectorization due to invalid loop-
>nb_iterations
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: tree-optimization
AssignedTo: dorit at il dot ibm dot com
ReportedBy: dorit at il dot ibm dot com
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: powerpc-apple-darwin7.0.0
GCC host triplet: powerpc-apple-darwin7.0.0
GCC target triplet: powerpc-apple-darwin7.0.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18400
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/18400] wrong unrolling after vectorization due to invalid loop->nb_iterations
2004-11-09 14:50 [Bug tree-optimization/18400] New: wrong unrolling after vectorization due to invalid loop->nb_iterations dorit at il dot ibm dot com
@ 2004-11-09 14:54 ` dorit at il dot ibm dot com
2004-11-09 14:56 ` pinskia at gcc dot gnu dot org
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: dorit at il dot ibm dot com @ 2004-11-09 14:54 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From dorit at il dot ibm dot com 2004-11-09 14:54 -------
Created an attachment (id=7502)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=7502&action=view)
testcase
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18400
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/18400] wrong unrolling after vectorization due to invalid loop->nb_iterations
2004-11-09 14:50 [Bug tree-optimization/18400] New: wrong unrolling after vectorization due to invalid loop->nb_iterations dorit at il dot ibm dot com
2004-11-09 14:54 ` [Bug tree-optimization/18400] " dorit at il dot ibm dot com
@ 2004-11-09 14:56 ` pinskia at gcc dot gnu dot org
2004-11-14 18:30 ` cvs-commit at gcc dot gnu dot org
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-11-09 14:56 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-11-09 14:56 -------
Confirmed.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |ASSIGNED
Ever Confirmed| |1
Keywords| |wrong-code
Last reconfirmed|0000-00-00 00:00:00 |2004-11-09 14:56:05
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18400
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/18400] wrong unrolling after vectorization due to invalid loop->nb_iterations
2004-11-09 14:50 [Bug tree-optimization/18400] New: wrong unrolling after vectorization due to invalid loop->nb_iterations dorit at il dot ibm dot com
2004-11-09 14:54 ` [Bug tree-optimization/18400] " dorit at il dot ibm dot com
2004-11-09 14:56 ` pinskia at gcc dot gnu dot org
@ 2004-11-14 18:30 ` cvs-commit at gcc dot gnu dot org
2004-11-14 18:33 ` pinskia at gcc dot gnu dot org
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: cvs-commit at gcc dot gnu dot org @ 2004-11-14 18:30 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From cvs-commit at gcc dot gnu dot org 2004-11-14 18:30 -------
Subject: Bug 18400
CVSROOT: /cvs/gcc
Module name: gcc
Changes by: dorit@gcc.gnu.org 2004-11-14 18:30:36
Modified files:
gcc : ChangeLog tree-vectorizer.c
Log message:
PR tree-opt/18400
* tree-vectorizer.c (make_loop_iterate_ntimes): Set loop->nb_iterations.
(vect_transform_loop_bound): Set loop->nb_iterations.
Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.6334&r2=2.6335
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-vectorizer.c.diff?cvsroot=gcc&r1=2.29&r2=2.30
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18400
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/18400] wrong unrolling after vectorization due to invalid loop->nb_iterations
2004-11-09 14:50 [Bug tree-optimization/18400] New: wrong unrolling after vectorization due to invalid loop->nb_iterations dorit at il dot ibm dot com
` (2 preceding siblings ...)
2004-11-14 18:30 ` cvs-commit at gcc dot gnu dot org
@ 2004-11-14 18:33 ` pinskia at gcc dot gnu dot org
2004-11-14 20:45 ` cvs-commit at gcc dot gnu dot org
2004-11-15 4:14 ` pinskia at gcc dot gnu dot org
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-11-14 18:33 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-11-14 18:33 -------
Fixed.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution| |FIXED
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18400
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/18400] wrong unrolling after vectorization due to invalid loop->nb_iterations
2004-11-09 14:50 [Bug tree-optimization/18400] New: wrong unrolling after vectorization due to invalid loop->nb_iterations dorit at il dot ibm dot com
` (3 preceding siblings ...)
2004-11-14 18:33 ` pinskia at gcc dot gnu dot org
@ 2004-11-14 20:45 ` cvs-commit at gcc dot gnu dot org
2004-11-15 4:14 ` pinskia at gcc dot gnu dot org
5 siblings, 0 replies; 7+ messages in thread
From: cvs-commit at gcc dot gnu dot org @ 2004-11-14 20:45 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From cvs-commit at gcc dot gnu dot org 2004-11-14 20:45 -------
Subject: Bug 18400
CVSROOT: /cvs/gcc
Module name: gcc
Changes by: dorit@gcc.gnu.org 2004-11-14 20:44:52
Modified files:
gcc/testsuite : ChangeLog
Added files:
gcc/testsuite/gcc.dg/vect: pr18400.c pr18425.c
Log message:
2004-11-14 Dorit Naishlos <dorit@il.ibm.com>
PR tree-opt/18400
* gcc.dg/vect/pr18400.c: New test.
2004-11-14 Dorit Naishlos <dorit@il.ibm.com>
Andrew Pinski <pinskia@physics.uc.edu>
PR tree-opt/18425
* gcc.dg/vect/pr18425.c: New test.
Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.4599&r2=1.4600
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/vect/pr18400.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/vect/pr18425.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18400
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/18400] wrong unrolling after vectorization due to invalid loop->nb_iterations
2004-11-09 14:50 [Bug tree-optimization/18400] New: wrong unrolling after vectorization due to invalid loop->nb_iterations dorit at il dot ibm dot com
` (4 preceding siblings ...)
2004-11-14 20:45 ` cvs-commit at gcc dot gnu dot org
@ 2004-11-15 4:14 ` pinskia at gcc dot gnu dot org
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-11-15 4:14 UTC (permalink / raw)
To: gcc-bugs
--
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |4.0.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18400
^ permalink raw reply [flat|nested] 7+ messages in thread
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2004-11-09 14:50 [Bug tree-optimization/18400] New: wrong unrolling after vectorization due to invalid loop->nb_iterations dorit at il dot ibm dot com
2004-11-09 14:54 ` [Bug tree-optimization/18400] " dorit at il dot ibm dot com
2004-11-09 14:56 ` pinskia at gcc dot gnu dot org
2004-11-14 18:30 ` cvs-commit at gcc dot gnu dot org
2004-11-14 18:33 ` pinskia at gcc dot gnu dot org
2004-11-14 20:45 ` cvs-commit at gcc dot gnu dot org
2004-11-15 4:14 ` pinskia at gcc dot gnu dot org
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