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* [Bug tree-optimization/18438] New: vectorizer failed for vector matrix multiplication
@ 2004-11-12 1:29 giovannibajo at libero dot it
2004-11-12 2:43 ` [Bug tree-optimization/18438] " pinskia at gcc dot gnu dot org
2005-09-20 17:47 ` pinskia at gcc dot gnu dot org
0 siblings, 2 replies; 3+ messages in thread
From: giovannibajo at libero dot it @ 2004-11-12 1:29 UTC (permalink / raw)
To: gcc-bugs
Vectorizer fails to handle this:
------------------------------------------------------------
#define NUMPOINTS 50000
#define align(x) __attribute__((align(x)))
typedef float align(16) MATRIX[3][3];
static float points[NUMPOINTS][4];
static align(16) float opoints[NUMPOINTS][4];
static bool flags[NUMPOINTS];
static MATRIX gmatrix;
void RotateVectors (void)
{
int i, r;
for (r = 0; r < 4; r++)
{
for (i = 0; i < NUMPOINTS; i++)
{
opoints[i][0] = gmatrix[0][0] * points[i][0]
+ gmatrix[0][1] * points[i][1]
+ gmatrix[0][2] * points[i][2];
opoints[i][1] = gmatrix[1][0] * points[i][0]
+ gmatrix[1][1] * points[i][1]
+ gmatrix[1][2] * points[i][2];
opoints[i][2] = gmatrix[2][0] * points[i][0]
+ gmatrix[2][1] * points[i][1]
+ gmatrix[2][2] * points[i][2];
flags[i] = true;
}
}
}
------------------------------------------------------------
loop at bench.cc:52: not vectorized: complicated access pattern.
loop at bench.cc:52: bad data access.
--
Summary: vectorizer failed for vector matrix multiplication
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P2
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: giovannibajo at libero dot it
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18438
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/18438] vectorizer failed for vector matrix multiplication
2004-11-12 1:29 [Bug tree-optimization/18438] New: vectorizer failed for vector matrix multiplication giovannibajo at libero dot it
@ 2004-11-12 2:43 ` pinskia at gcc dot gnu dot org
2005-09-20 17:47 ` pinskia at gcc dot gnu dot org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-11-12 2:43 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-11-12 02:43 -------
Confirmed, ICC can do this but does not because it is not very inefficient to do it.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed| |1
Last reconfirmed|0000-00-00 00:00:00 |2004-11-12 02:43:35
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18438
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/18438] vectorizer failed for vector matrix multiplication
2004-11-12 1:29 [Bug tree-optimization/18438] New: vectorizer failed for vector matrix multiplication giovannibajo at libero dot it
2004-11-12 2:43 ` [Bug tree-optimization/18438] " pinskia at gcc dot gnu dot org
@ 2005-09-20 17:47 ` pinskia at gcc dot gnu dot org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-09-20 17:47 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-09-20 17:47 -------
t.c:20: note: not vectorized: mixed data-types
t.c:20: note: can't determine vectorization factor.
Removing flags[i] = true;
we get:
t.c:20: note: not consecutive access
t.c:20: note: not vectorized: complicated access pattern.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18438
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2005-09-20 17:47 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2004-11-12 1:29 [Bug tree-optimization/18438] New: vectorizer failed for vector matrix multiplication giovannibajo at libero dot it
2004-11-12 2:43 ` [Bug tree-optimization/18438] " pinskia at gcc dot gnu dot org
2005-09-20 17:47 ` pinskia at gcc dot gnu dot org
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