http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58028
--- Comment #9 from Tobias Grosser <grosser at gcc dot gnu.org> --- (In reply to rguent...@suse.de from comment #8) > 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. Only in cases where the schedule is not in 2D + 1 form. In case the schedule is in 2D + 1 form int scheduling_dim = isl_set_n_dim (domain); will be equal to 2 * depth + 1. > 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; The change you propose seems conservatively correct, as in that loops that are not in 2D + 1 form are not detected to be parallel. This change may hide the bug, but I don't see any bug it solves. > no time to check whether reverting the other hunk plus this will > resolve the bug the revision fixed and restores the testcases. I assume it will fix the crash, but it will not detect parallellism in none 2D+1 loops, something the isl scheduler happily creates.
