------- Comment #2 from rguenth at gcc dot gnu dot org 2010-07-23 12:35 -------
Confirmed. We end up vectorizing
void
foo (int *a, int n)
{
int *lasta = a + n;
for (; a != lasta; a++)
{
*a *= 2;
a[1] = a[-1] + a[-2];
}
}
not seeing the dependence of *a vs a[-1] because via
initialize_data_dependence_relation we ask the alias-oracle whether
*a may alias a[-1] (which it doesn't). So we end up not computing
a dependence distance.
May we not use the alias-oracle (on the full ref) here?
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |spop at gcc dot gnu dot org
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2010-07-23 12:35:43
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44913
