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From: "rguenther at suse dot de" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/58028] [4.9 Regression] Several failures in libgomp.graphite after revision 200946
Date: Wed, 29 Jan 2014 12:40:00 -0000
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58028

--- Comment #8 from rguenther at suse dot de <rguenther at suse dot de> ---
On Wed, 29 Jan 2014, dominiq at lps dot ens.fr wrote:

> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58028
> 
> --- Comment #7 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
> > The testsuite failures are.  We have to do sth about them.
> 
> Revert r200946?

Probably - the

+       * graphite-dependences.c (carries_deps): Do not assume the 
schedule is
+         in 2D + 1 form.

part looks wrong.

-  idx = 2 * depth + 1;
-  for (i = 0; i < idx; i++)
+  for (i = 0; i < depth - 1; i++)

we now iterate over less dimensions than before.

I'd say we should simply check whether the loop _is_ in 2D + 1 form
at

+  isl_set *domain = isl_set_from_cloog_domain (stmt->domain);
+  int scheduling_dim = isl_set_n_dim (domain);
+
   if (flag_loop_parallelize_all
-      && loop_is_parallel_p (loop, bb_pbb_mapping, level))
+      && loop_is_parallel_p (loop, bb_pbb_mapping, scheduling_dim))
     loop->can_be_parallel = true;

thus

   if (flag_loop_parallelize_all
       && scheduling_dim == 2 * level + 1
       && loop_is_parallel_p (loop, bb_pbb_mapping, level)
     loop->can_be_parallel = true;

no time to check whether reverting the other hunk plus this will
resolve the bug the revision fixed and restores the testcases.