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* [Bug tree-optimization/25881] New: unsigned int loop indices are not accepted by the vectorizer
@ 2006-01-20 17:11 David dot Monniaux at ens dot fr
2006-01-20 17:32 ` [Bug tree-optimization/25881] " pinskia at gcc dot gnu dot org
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: David dot Monniaux at ens dot fr @ 2006-01-20 17:11 UTC (permalink / raw)
To: gcc-bugs
void vector_add(int n,
double * __restrict__ r,
double * __restrict__ a,
double * __restrict__ b) {
int i;
for(i=0; i<n; i++) {
r[i] = a[i] + b[i];
}
}
gets vectorized.
If i is of type 'unsigned int', the loop does not get vectorized.
--
Summary: unsigned int loop indices are not accepted by the
vectorizer
Product: gcc
Version: 4.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: David dot Monniaux at ens dot fr
GCC build triplet: x86_64-unknown-linux-gnu
GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25881
^ permalink raw reply [flat|nested] 5+ messages in thread* [Bug tree-optimization/25881] unsigned int loop indices are not accepted by the vectorizer
2006-01-20 17:11 [Bug tree-optimization/25881] New: unsigned int loop indices are not accepted by the vectorizer David dot Monniaux at ens dot fr
@ 2006-01-20 17:32 ` pinskia at gcc dot gnu dot org
2006-01-20 20:43 ` [Bug tree-optimization/25881] unsigned int loop indices don't optimize as good as int or __SIZE_TYPE__ for 64bit targets pinskia at gcc dot gnu dot org
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2006-01-20 17:32 UTC (permalink / raw)
To: gcc-bugs
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Severity|normal |enhancement
GCC build triplet|x86_64-unknown-linux-gnu |
GCC host triplet|x86_64-unknown-linux-gnu |
GCC target triplet|x86_64-unknown-linux-gnu |64bits targets
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25881
^ permalink raw reply [flat|nested] 5+ messages in thread* [Bug tree-optimization/25881] unsigned int loop indices don't optimize as good as int or __SIZE_TYPE__ for 64bit targets
2006-01-20 17:11 [Bug tree-optimization/25881] New: unsigned int loop indices are not accepted by the vectorizer David dot Monniaux at ens dot fr
2006-01-20 17:32 ` [Bug tree-optimization/25881] " pinskia at gcc dot gnu dot org
@ 2006-01-20 20:43 ` pinskia at gcc dot gnu dot org
2006-01-29 10:10 ` irar at il dot ibm dot com
2006-10-30 2:46 ` pinskia at gcc dot gnu dot org
3 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2006-01-20 20:43 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from pinskia at gcc dot gnu dot org 2006-01-20 20:43 -------
Confirmed, I thought I had saw another bug about this but no luck, anyways
confirmed.
Hmm, using unsigned short on 32bit targets cause the same issue:
void vector_add(unsigned short n,
double * __restrict__ r,
double * __restrict__ a,
double * __restrict__ b) {
unsigned short i;
for(i=0; i<n; i++) {
r[i] = a[i] + b[i];
}
}
There more likely other issues like this too.
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Keywords| |missed-optimization
Last reconfirmed|0000-00-00 00:00:00 |2006-01-20 20:43:27
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25881
^ permalink raw reply [flat|nested] 5+ messages in thread* [Bug tree-optimization/25881] unsigned int loop indices don't optimize as good as int or __SIZE_TYPE__ for 64bit targets
2006-01-20 17:11 [Bug tree-optimization/25881] New: unsigned int loop indices are not accepted by the vectorizer David dot Monniaux at ens dot fr
2006-01-20 17:32 ` [Bug tree-optimization/25881] " pinskia at gcc dot gnu dot org
2006-01-20 20:43 ` [Bug tree-optimization/25881] unsigned int loop indices don't optimize as good as int or __SIZE_TYPE__ for 64bit targets pinskia at gcc dot gnu dot org
@ 2006-01-29 10:10 ` irar at il dot ibm dot com
2006-10-30 2:46 ` pinskia at gcc dot gnu dot org
3 siblings, 0 replies; 5+ messages in thread
From: irar at il dot ibm dot com @ 2006-01-29 10:10 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from irar at il dot ibm dot com 2006-01-29 10:10 -------
Changing double to float, the scalar evolution analyzer returns access function
(float *) ((unsigned int) {0, +, 1}_1 * 4) + (float *) a_12,
since it fails in type conversion:
(failed conversion:
type: unsigned int
base: 0
step:
estimated_nb_iterations: scev_not_known
)
(Without type conversion we get {(float *) a_14, +, 4B}_1).
Data-refs analysis fails to analyze the access pattern, therefore the loop does
not get vectorized.
--
irar at il dot ibm dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |sebastian dot pop at cri dot
| |ensmp dot fr, irar at il dot
| |ibm dot com
Last reconfirmed|2006-01-20 20:43:27 |2006-01-29 10:10:55
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25881
^ permalink raw reply [flat|nested] 5+ messages in thread* [Bug tree-optimization/25881] unsigned int loop indices don't optimize as good as int or __SIZE_TYPE__ for 64bit targets
2006-01-20 17:11 [Bug tree-optimization/25881] New: unsigned int loop indices are not accepted by the vectorizer David dot Monniaux at ens dot fr
` (2 preceding siblings ...)
2006-01-29 10:10 ` irar at il dot ibm dot com
@ 2006-10-30 2:46 ` pinskia at gcc dot gnu dot org
3 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2006-10-30 2:46 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from pinskia at gcc dot gnu dot org 2006-10-30 02:46 -------
Fixed in 4.2.0.
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |FIXED
Target Milestone|--- |4.2.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25881
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2006-10-30 2:46 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2006-01-20 17:11 [Bug tree-optimization/25881] New: unsigned int loop indices are not accepted by the vectorizer David dot Monniaux at ens dot fr
2006-01-20 17:32 ` [Bug tree-optimization/25881] " pinskia at gcc dot gnu dot org
2006-01-20 20:43 ` [Bug tree-optimization/25881] unsigned int loop indices don't optimize as good as int or __SIZE_TYPE__ for 64bit targets pinskia at gcc dot gnu dot org
2006-01-29 10:10 ` irar at il dot ibm dot com
2006-10-30 2:46 ` pinskia at gcc dot gnu dot org
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