------- Comment #1 from spop at gcc dot gnu dot org 2009-08-19 16:02 -------
> since both a and b have alias set 0,
> a[0][i0] and b[0][i1] are considered independent for i0 != i1.
You mean mem[0][i0] and mem[0][i1], and in your example
for (i = 0; i < n; i++)
mem[0][i] = mem[0][i];
that would be a read and a write in the same location: that means
that there is no dependence carried by the loop, and thus the loop
is considered parallel. Yes this is a bug in the data dependence
analysis.
I wonder why the alias analysis improvements by Li do not assign
different alias sets for "a" and "b" in this case. I will have to try
to reproduce this bug first.
Sebastian
--
spop at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|unassigned at gcc dot gnu |spop at gcc dot gnu dot org
|dot org |
Status|UNCONFIRMED |ASSIGNED
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2009-08-19 16:02:20
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41118
