chf...@pathscale:~/gcc$ cat foo.c
int a[100], b[100];
void foo(int n, int mid)
{
int i, t = 0;
for(i=0; i<n; i++)
{
a[i] = b[i] + t;
t = b[i];
}
}
chf...@pathscale:~/gcc$ gcc -O3 -ftree-vectorizer-verbose=7 -c foo.c
foo.c:6: note: not vectorized: unsupported use in stmt.
foo.c:3: note: vectorized 0 loops in function.
scalar expansion of t into array to carry the values accross iteration.
--
Summary: enhance scalar expansion to vectorize this loop
Product: gcc
Version: 4.5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
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=43425
