[Bug libgomp/49490] suboptimal load balancing in loops

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49490

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-06-22 20:39:27 UTC ---
Author: jakub
Date: Wed Jun 22 20:39:25 2011
New Revision: 175315

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=175315
Log:
    PR libgomp/49490
    * omp-low.c (expand_omp_for_static_nochunk): Only
    use n ceil/ nthreads size for the first
    n % nthreads threads in the team instead of
    all threads except for the last few ones which
    get less work or none at all.

    * iter.c (gomp_iter_static_next): For chunk size 0
    only use n ceil/ nthreads size for the first
    n % nthreads threads in the team instead of
    all threads except for the last few ones which
    get less work or none at all.
    * iter_ull.c (gomp_iter_ull_static_next): Likewise.
    * env.c (parse_schedule): If OMP_SCHEDULE doesn't have
    chunk argument, set run_sched_modifier to 0 for static
    resp. 1 for other kinds.  If chunk argument is 0
    and not static, set value to 1.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/omp-low.c
    trunk/libgomp/ChangeLog
    trunk/libgomp/env.c
    trunk/libgomp/iter.c
    trunk/libgomp/iter_ull.c