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* [Bug tree-optimization/60012] New: Vectorizer generates unnecessary loop versioning for alias
@ 2014-01-31 17:18 bmei at broadcom dot com
2014-02-03 14:44 ` [Bug tree-optimization/60012] " rguenth at gcc dot gnu.org
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: bmei at broadcom dot com @ 2014-01-31 17:18 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60012
Bug ID: 60012
Summary: Vectorizer generates unnecessary loop versioning for
alias
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: bmei at broadcom dot com
typedef struct
{
short real;
short imag;
} complex16_t;
void
libvector_AccSquareNorm_ref (unsigned long long *acc,
const complex16_t *x, unsigned len)
{
for (unsigned i = 0; i < len; i++)
{
acc[i] +=
((unsigned long long)((int)x[i].real * x[i].real)) +
((unsigned long long)((int)x[i].imag * x[i].imag));
}
}
Compiler the code with
~/scratch/install-x86/bin/gcc tst.c -O2 -S -ftree-vectorize
-fdump-tree-vect-details -std=c99
GCC generates unnecessary loop versioning because it cannot disambiguate mem
accesses.
tst.c:12:5: note: versioning for alias required: can't determine dependence
between *_8 and _12->real
tst.c:12:5: note: mark for run-time aliasing test between *_8 and _12->real
This should be handled by TBAA info as acc & x clearly point to different data
types. But unfortunately, TBAA doesn't handle Anti- & Output- dependencies.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/60012] Vectorizer generates unnecessary loop versioning for alias
2014-01-31 17:18 [Bug tree-optimization/60012] New: Vectorizer generates unnecessary loop versioning for alias bmei at broadcom dot com
@ 2014-02-03 14:44 ` rguenth at gcc dot gnu.org
2014-02-04 9:35 ` rguenth at gcc dot gnu.org
2014-02-04 9:35 ` rguenth at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: rguenth at gcc dot gnu.org @ 2014-02-03 14:44 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60012
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |ASSIGNED
Last reconfirmed| |2014-02-03
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org
Ever confirmed|0 |1
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Mine.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/60012] Vectorizer generates unnecessary loop versioning for alias
2014-01-31 17:18 [Bug tree-optimization/60012] New: Vectorizer generates unnecessary loop versioning for alias bmei at broadcom dot com
2014-02-03 14:44 ` [Bug tree-optimization/60012] " rguenth at gcc dot gnu.org
@ 2014-02-04 9:35 ` rguenth at gcc dot gnu.org
2014-02-04 9:35 ` rguenth at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: rguenth at gcc dot gnu.org @ 2014-02-04 9:35 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60012
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue Feb 4 09:34:58 2014
New Revision: 207455
URL: http://gcc.gnu.org/viewcvs?rev=207455&root=gcc&view=rev
Log:
2014-02-04 Richard Biener <rguenther@suse.de>
PR tree-optimization/60012
* tree-vect-data-refs.c (vect_analyze_data_ref_dependence): Apply
TBAA disambiguation to all DDRs.
* gcc.dg/vect/pr60012.c: New testcase.
Added:
trunk/gcc/testsuite/gcc.dg/vect/pr60012.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/testsuite/ChangeLog
trunk/gcc/tree-vect-data-refs.c
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/60012] Vectorizer generates unnecessary loop versioning for alias
2014-01-31 17:18 [Bug tree-optimization/60012] New: Vectorizer generates unnecessary loop versioning for alias bmei at broadcom dot com
2014-02-03 14:44 ` [Bug tree-optimization/60012] " rguenth at gcc dot gnu.org
2014-02-04 9:35 ` rguenth at gcc dot gnu.org
@ 2014-02-04 9:35 ` rguenth at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: rguenth at gcc dot gnu.org @ 2014-02-04 9:35 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60012
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Known to work| |4.9.0
Resolution|--- |FIXED
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed for 4.9.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2014-01-31 17:18 [Bug tree-optimization/60012] New: Vectorizer generates unnecessary loop versioning for alias bmei at broadcom dot com
2014-02-03 14:44 ` [Bug tree-optimization/60012] " rguenth at gcc dot gnu.org
2014-02-04 9:35 ` rguenth at gcc dot gnu.org
2014-02-04 9:35 ` rguenth at gcc dot gnu.org
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