On 12/10/15 16:11, Bernd Schmidt wrote:
On 10/10/2015 01:58 PM, Tom de Vries wrote:
Handle original loop tree in expand_omp_for_generic
2015-09-10 Tom de Vries<t...@codesourcery.com>
PR tree-optimization/67476
* omp-low.c (expand_omp_for_generic): Handle original loop tree.
This one I find slightly confusing.
- add_bb_to_loop (l2_bb, cont_bb->loop_father);
+ struct loop *loop = l1_bb->loop_father;
+ add_bb_to_loop (l2_bb, entry_bb->loop_father);
add_loop (outer_loop, l0_bb->loop_father);
Looks like a lot of bb's loop_father is being looked at. Are all or some
of these supposed to be the same? I think I'd like one (appropriately
named) struct loop * variable for each loop that's involved here.
Done.
There's a comment suggesting that there can be different situations, it
would be good to expand that to explain how they can arise.
- struct loop *loop = alloc_loop ();
+ loop = alloc_loop ();
Also, I think it would be preferrable to not reuse that loop variable
but make a new one instead.
Does this version look better?
Thanks,
- Tom
Handle original loop tree in expand_omp_for_generic
2015-09-12 Tom de Vries <t...@codesourcery.com>
PR tree-optimization/67476
* omp-low.c (expand_omp_for_generic): Handle original loop tree.
---
gcc/omp-low.c | 30 +++++++++++++++++++++---------
1 file changed, 21 insertions(+), 9 deletions(-)
diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index b2a93b9..b957428 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -6439,7 +6439,6 @@ expand_omp_for_generic (struct omp_region *region,
remove_edge (e);
make_edge (cont_bb, l2_bb, EDGE_FALSE_VALUE);
- add_bb_to_loop (l2_bb, cont_bb->loop_father);
e = find_edge (cont_bb, l1_bb);
if (e == NULL)
{
@@ -6516,17 +6515,30 @@ expand_omp_for_generic (struct omp_region *region,
set_immediate_dominator (CDI_DOMINATORS, l1_bb,
recompute_dominator (CDI_DOMINATORS, l1_bb));
- struct loop *outer_loop = alloc_loop ();
- outer_loop->header = l0_bb;
- outer_loop->latch = l2_bb;
- add_loop (outer_loop, l0_bb->loop_father);
+ /* We enter expand_omp_for_generic with a loop. This original loop may
+ have its own loop struct, or it may be part of an outer loop struct
+ (which may be the fake loop). */
+ struct loop *outer_loop = entry_bb->loop_father;
+ bool orig_loop_has_loop_struct = l1_bb->loop_father != outer_loop;
- if (!gimple_omp_for_combined_p (fd->for_stmt))
+ add_bb_to_loop (l2_bb, outer_loop);
+
+ /* We've added a new loop around the original loop. Allocate the
+ corresponding loop struct. */
+ struct loop *new_loop = alloc_loop ();
+ new_loop->header = l0_bb;
+ new_loop->latch = l2_bb;
+ add_loop (new_loop, outer_loop);
+
+ if (/* If we already have a loop struct for the original loop, don't
+ allocate a new one. */
+ !orig_loop_has_loop_struct
+ && !gimple_omp_for_combined_p (fd->for_stmt))
{
- struct loop *loop = alloc_loop ();
- loop->header = l1_bb;
+ struct loop *orig_loop = alloc_loop ();
+ orig_loop->header = l1_bb;
/* The loop may have multiple latches. */
- add_loop (loop, outer_loop);
+ add_loop (orig_loop, new_loop);
}
}
}
--
1.9.1
