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* [Bug tree-optimization/43428] New: vectorizer should invoke loop distribution to partially vectorize this loop
@ 2010-03-18 18:57 changpeng dot fang at amd dot com
0 siblings, 0 replies; only message in thread
From: changpeng dot fang at amd dot com @ 2010-03-18 18:57 UTC (permalink / raw)
To: gcc-bugs
chfang@pathscale:~/gcc$ cat foo.c
float a[100], b[100], c[100];
void foo(int n)
{
int i;
for(i=1; i<n; i++)
{
a[i] = a[i] + c[i];
b[i] = b[i-1] + a[i];
}
}
chfang@pathscale:~/gcc$ gcc -O3 -ftree-vectorizer-verbose=2
-ftree-loop-distribution -c foo.c
foo.c:6: note: not vectorized, possible dependence between data-refs
b[D.2730_7] and b[i_17]
foo.c:3: note: vectorized 0 loops in function.
Loop distribution itself may find not profitable to do such distribution.
However, partially vectorize this loop may obtain big profit. ICC can partially
vectorize it.
--
Summary: vectorizer should invoke loop distribution to partially
vectorize this loop
Product: gcc
Version: 4.5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: changpeng dot fang at amd dot com
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43428
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2010-03-18 18:57 [Bug tree-optimization/43428] New: vectorizer should invoke loop distribution to partially vectorize this loop changpeng dot fang at amd dot com
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