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* [Bug tree-optimization/36493] New: [4.3/4.4 Regression] vectorizer aliasing bug
@ 2008-06-10 20:06 jsm28 at gcc dot gnu dot org
2008-06-11 8:01 ` [Bug tree-optimization/36493] " irar at il dot ibm dot com
` (7 more replies)
0 siblings, 8 replies; 9+ messages in thread
From: jsm28 at gcc dot gnu dot org @ 2008-06-10 20:06 UTC (permalink / raw)
To: gcc-bugs
The following code aborts if built for i686-pc-linux-gnu with -msse2 -O3.
extern void abort (void);
int
main (void)
{
int i;
long x[12] __attribute__((aligned(16)));
x[0] = 1;
for (i = 0; i < 12; i++)
x[i] = i;
if (x[0] != 0)
abort ();
return 0;
}
The loop gets vectorized using "vector int *" pointers, and then the compiler
decides that "vector int" writes don't conflict with "long" reads. (If an
array of int is used instead, the test passes.)
(Not x86-specific; originally observed as a failure of
gcc.c-torture/execute/loop-13.c on SPE with an unsubmitted patch to support
autovectorization there.)
--
Summary: [4.3/4.4 Regression] vectorizer aliasing bug
Product: gcc
Version: 4.4.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: jsm28 at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36493
^ permalink raw reply [flat|nested] 9+ messages in thread* [Bug tree-optimization/36493] [4.3/4.4 Regression] vectorizer aliasing bug 2008-06-10 20:06 [Bug tree-optimization/36493] New: [4.3/4.4 Regression] vectorizer aliasing bug jsm28 at gcc dot gnu dot org @ 2008-06-11 8:01 ` irar at il dot ibm dot com 2008-06-11 8:37 ` rguenth at gcc dot gnu dot org ` (6 subsequent siblings) 7 siblings, 0 replies; 9+ messages in thread From: irar at il dot ibm dot com @ 2008-06-11 8:01 UTC (permalink / raw) To: gcc-bugs ------- Comment #1 from irar at il dot ibm dot com 2008-06-11 08:00 ------- Reproduced on powerpc64-suse-linux. Doesn't occur when compiled with -O2 -ftree-vectorize instead of -O3 (the vectorizer generates the same code in both cases). -- irar at il dot ibm dot com changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed|0 |1 Last reconfirmed|0000-00-00 00:00:00 |2008-06-11 08:00:41 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36493 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug tree-optimization/36493] [4.3/4.4 Regression] vectorizer aliasing bug 2008-06-10 20:06 [Bug tree-optimization/36493] New: [4.3/4.4 Regression] vectorizer aliasing bug jsm28 at gcc dot gnu dot org 2008-06-11 8:01 ` [Bug tree-optimization/36493] " irar at il dot ibm dot com @ 2008-06-11 8:37 ` rguenth at gcc dot gnu dot org 2008-06-11 11:16 ` jsm28 at gcc dot gnu dot org ` (5 subsequent siblings) 7 siblings, 0 replies; 9+ messages in thread From: rguenth at gcc dot gnu dot org @ 2008-06-11 8:37 UTC (permalink / raw) To: gcc-bugs ------- Comment #2 from rguenth at gcc dot gnu dot org 2008-06-11 08:37 ------- Vectors have the alias set of their element type and int and long do not have conflicting alias sets. The vectorizer clearly should choose vector long * instead of vector int *. -- rguenth at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |rguenth at gcc dot gnu dot | |org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36493 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug tree-optimization/36493] [4.3/4.4 Regression] vectorizer aliasing bug 2008-06-10 20:06 [Bug tree-optimization/36493] New: [4.3/4.4 Regression] vectorizer aliasing bug jsm28 at gcc dot gnu dot org 2008-06-11 8:01 ` [Bug tree-optimization/36493] " irar at il dot ibm dot com 2008-06-11 8:37 ` rguenth at gcc dot gnu dot org @ 2008-06-11 11:16 ` jsm28 at gcc dot gnu dot org 2008-06-13 21:45 ` mmitchel at gcc dot gnu dot org ` (4 subsequent siblings) 7 siblings, 0 replies; 9+ messages in thread From: jsm28 at gcc dot gnu dot org @ 2008-06-11 11:16 UTC (permalink / raw) To: gcc-bugs -- jsm28 at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|--- |4.3.2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36493 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug tree-optimization/36493] [4.3/4.4 Regression] vectorizer aliasing bug 2008-06-10 20:06 [Bug tree-optimization/36493] New: [4.3/4.4 Regression] vectorizer aliasing bug jsm28 at gcc dot gnu dot org ` (2 preceding siblings ...) 2008-06-11 11:16 ` jsm28 at gcc dot gnu dot org @ 2008-06-13 21:45 ` mmitchel at gcc dot gnu dot org 2008-06-16 10:40 ` irar at gcc dot gnu dot org ` (3 subsequent siblings) 7 siblings, 0 replies; 9+ messages in thread From: mmitchel at gcc dot gnu dot org @ 2008-06-13 21:45 UTC (permalink / raw) To: gcc-bugs -- mmitchel at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Priority|P3 |P1 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36493 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug tree-optimization/36493] [4.3/4.4 Regression] vectorizer aliasing bug 2008-06-10 20:06 [Bug tree-optimization/36493] New: [4.3/4.4 Regression] vectorizer aliasing bug jsm28 at gcc dot gnu dot org ` (3 preceding siblings ...) 2008-06-13 21:45 ` mmitchel at gcc dot gnu dot org @ 2008-06-16 10:40 ` irar at gcc dot gnu dot org 2008-06-16 10:44 ` irar at gcc dot gnu dot org ` (2 subsequent siblings) 7 siblings, 0 replies; 9+ messages in thread From: irar at gcc dot gnu dot org @ 2008-06-16 10:40 UTC (permalink / raw) To: gcc-bugs ------- Comment #3 from irar at gcc dot gnu dot org 2008-06-16 10:39 ------- Subject: Bug 36493 Author: irar Date: Mon Jun 16 10:39:07 2008 New Revision: 136843 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=136843 Log: PR tree-optimization/36493 * tree-vect-transform.c (vect_create_data_ref_ptr): Remove TYPE from the arguments list. Use VECTYPE to create vector pointer. (vectorizable_store): Fail if accesses through a pointer to vectype do not alias the original memory reference operands. Call vect_create_data_ref_ptr without the removed argument. (vectorizable_load): Likewise. (vect_setup_realignment): Call vect_create_data_ref_ptr without the removed argument. Added: trunk/gcc/testsuite/gcc.dg/vect/pr36493.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-vect-transform.c -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36493 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug tree-optimization/36493] [4.3/4.4 Regression] vectorizer aliasing bug 2008-06-10 20:06 [Bug tree-optimization/36493] New: [4.3/4.4 Regression] vectorizer aliasing bug jsm28 at gcc dot gnu dot org ` (4 preceding siblings ...) 2008-06-16 10:40 ` irar at gcc dot gnu dot org @ 2008-06-16 10:44 ` irar at gcc dot gnu dot org 2008-06-17 11:50 ` irar at il dot ibm dot com 2008-12-28 1:17 ` pinskia at gcc dot gnu dot org 7 siblings, 0 replies; 9+ messages in thread From: irar at gcc dot gnu dot org @ 2008-06-16 10:44 UTC (permalink / raw) To: gcc-bugs ------- Comment #4 from irar at gcc dot gnu dot org 2008-06-16 10:43 ------- Subject: Bug 36493 Author: irar Date: Mon Jun 16 10:42:56 2008 New Revision: 136844 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=136844 Log: PR tree-optimization/36493 * tree-vect-transform.c (vect_create_data_ref_ptr): Remove TYPE from the arguments list. Use VECTYPE to create vector pointer. (vectorizable_store): Fail if accesses through a pointer to vectype do not alias the original memory reference operands. Call vect_create_data_ref_ptr without the removed argument. (vectorizable_load): Likewise. (vect_setup_realignment): Call vect_create_data_ref_ptr without the removed argument. Added: branches/gcc-4_3-branch/gcc/testsuite/gcc.dg/vect/pr36493.c Modified: branches/gcc-4_3-branch/gcc/ChangeLog branches/gcc-4_3-branch/gcc/testsuite/ChangeLog branches/gcc-4_3-branch/gcc/tree-vect-transform.c -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36493 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug tree-optimization/36493] [4.3/4.4 Regression] vectorizer aliasing bug 2008-06-10 20:06 [Bug tree-optimization/36493] New: [4.3/4.4 Regression] vectorizer aliasing bug jsm28 at gcc dot gnu dot org ` (5 preceding siblings ...) 2008-06-16 10:44 ` irar at gcc dot gnu dot org @ 2008-06-17 11:50 ` irar at il dot ibm dot com 2008-12-28 1:17 ` pinskia at gcc dot gnu dot org 7 siblings, 0 replies; 9+ messages in thread From: irar at il dot ibm dot com @ 2008-06-17 11:50 UTC (permalink / raw) To: gcc-bugs ------- Comment #5 from irar at il dot ibm dot com 2008-06-17 11:49 ------- Fixed. -- irar at il dot ibm dot com changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Priority|P1 |P3 Resolution| |FIXED Target Milestone|4.3.2 |--- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36493 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug tree-optimization/36493] [4.3/4.4 Regression] vectorizer aliasing bug 2008-06-10 20:06 [Bug tree-optimization/36493] New: [4.3/4.4 Regression] vectorizer aliasing bug jsm28 at gcc dot gnu dot org ` (6 preceding siblings ...) 2008-06-17 11:50 ` irar at il dot ibm dot com @ 2008-12-28 1:17 ` pinskia at gcc dot gnu dot org 7 siblings, 0 replies; 9+ messages in thread From: pinskia at gcc dot gnu dot org @ 2008-12-28 1:17 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 Target Milestone|--- |4.3.2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36493 ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2008-12-28 1:17 UTC | newest] Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2008-06-10 20:06 [Bug tree-optimization/36493] New: [4.3/4.4 Regression] vectorizer aliasing bug jsm28 at gcc dot gnu dot org 2008-06-11 8:01 ` [Bug tree-optimization/36493] " irar at il dot ibm dot com 2008-06-11 8:37 ` rguenth at gcc dot gnu dot org 2008-06-11 11:16 ` jsm28 at gcc dot gnu dot org 2008-06-13 21:45 ` mmitchel at gcc dot gnu dot org 2008-06-16 10:40 ` irar at gcc dot gnu dot org 2008-06-16 10:44 ` irar at gcc dot gnu dot org 2008-06-17 11:50 ` irar at il dot ibm dot com 2008-12-28 1:17 ` pinskia at gcc dot gnu dot org
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