[PATCH][2/5] Handle simple latch bb in expand_omp_for_static_chunk

[Tom de Vries <Tom_deVries at mentor dot com>]

On 31/08/15 13:41, Tom de Vries wrote:
> On 15/04/15 15:10, Tom de Vries wrote:
> > Hi,
> >
> > This patch series fixes PR65637.
> >
> > Currently, ssa-handling code in expand_omp_for_static_chunk is dead and
> > not exercised by testing.
> >
> > Ssa-handling code in omp-low.c is only triggered by
> > pass_parallelize_loops, and that pass doesn't specify a chunk size on
> > the GIMPLE_OMP_FOR it constructs, so that only exercises the
> > expand_omp_for_static_nochunk path.
> >
> > Using the attached trigger patch, we excercise the ssa-handling code in
> > expand_omp_for_static_chunk.
>  >
>  > 1. Fix gcc_assert in expand_omp_for_static_chunk
>  > 2. Fix inner loop phi in expand_omp_for_static_chunk
>  > 3. Handle 2 preds for fin_bb in expand_omp_for_static_chunk
>
> I'm posting an updated series.
>
> 1. Add param parloops-chunk-size
> 2. Handle simple latch bb in expand_omp_for_static_chunk
> 3. Fix gcc_assert in expand_omp_for_static_chunk
> 4. Fix inner loop phi in expand_omp_for_static_chunk
> 5. Handle 2 preds for fin_bb in expand_omp_for_static_chunk
>
> There are two new patches, (1) and (2) in the new numbering.
>
> The first patch adds a param parloops-chunk-size, which means the
> ssa-handling code in expand_omp_for_static_chunk is no longer dead.
>
> The second patch handles simple latches in expand_omp_for_static_chunk,
> similar to the fix for PR66846 in expand_omp_for_static_nochunk.
>
> The rest of the patches are now updated to include the testcases (and
> patch number 4 has been updated to handle simple latches).
>
> The patch series has been bootstrapped and reg-tested on x86_64.
>
> I'll post the patches from the patch series individually. The first two
> in response to this email, the latter three in response to the earlier
> submissions.

Hi,

this patch handles simple latches in expand_omp_for_static_chunk, 
similar to how it's done for expand_omp_for_static_nochunk in the fix 
for PR66846 ( 
https://gcc.gnu.org/viewcvs/gcc/trunk/gcc/omp-low.c?annotate=226427&pathrev=226427#l6539 
).

Thanks,
- Tom

Handle simple latch bb in expand_omp_for_static_chunk

2015-08-31  Tom de Vries  <tom@codesourcery.com>

	* omp-low.c (expand_omp_for_static_chunk): Handle simple latch bb.
---
 gcc/omp-low.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index aa2a598..c3dfc51 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -6960,7 +6960,8 @@ expand_omp_for_static_chunk (struct omp_region *region,
   body_bb = single_succ (seq_start_bb);
   if (!broken_loop)
     {
-      gcc_assert (BRANCH_EDGE (cont_bb)->dest == body_bb);
+      gcc_assert (BRANCH_EDGE (cont_bb)->dest == body_bb
+		  || single_succ (BRANCH_EDGE (cont_bb)->dest) == body_bb);
       gcc_assert (EDGE_COUNT (cont_bb->succs) == 2);
       trip_update_bb = split_edge (FALLTHRU_EDGE (cont_bb));
     }
@@ -7261,6 +7262,11 @@ expand_omp_for_static_chunk (struct omp_region *region,
   if (!broken_loop)
     {
       se = find_edge (cont_bb, body_bb);
+      if (se == NULL)
+	{
+	  se = BRANCH_EDGE (cont_bb);
+	  gcc_assert (single_succ (se->dest) == body_bb);
+	}
       if (gimple_omp_for_combined_p (fd->for_stmt))
 	{
 	  remove_edge (se);
@@ -7351,14 +7357,25 @@ expand_omp_for_static_chunk (struct omp_region *region,
 
   if (!broken_loop)
     {
+      struct loop *loop = body_bb->loop_father;
       struct loop *trip_loop = alloc_loop ();
       trip_loop->header = iter_part_bb;
       trip_loop->latch = trip_update_bb;
       add_loop (trip_loop, iter_part_bb->loop_father);
 
+      if (loop != entry_bb->loop_father)
+	{
+	  gcc_assert (loop->header == body_bb);
+	  gcc_assert (broken_loop
+		      || loop->latch == region->cont
+		      || single_pred (loop->latch) == region->cont);
+	  trip_loop->inner = loop;
+	  return;
+	}
+
       if (!gimple_omp_for_combined_p (fd->for_stmt))
 	{
-	  struct loop *loop = alloc_loop ();
+	  loop = alloc_loop ();
 	  loop->header = body_bb;
 	  if (collapse_bb == NULL)
 	    loop->latch = cont_bb;
-- 
1.9.1