Don't cancel loop tree in parloops

2015-07-31  Tom de Vries  <tom@codesourcery.com>

	PR tree-optimization/66846
	* omp-low.c (expand_omp_taskreg) [ENABLE_CHECKING]: Call
	verify_loop_structure for child_cfun if !LOOPS_NEED_FIXUP.
	(expand_omp_target) [ENABLE_CHECKING]: Same.
	(execute_expand_omp) [ENABLE_CHECKING]: Call verify_loop_structure for
	cfun if !LOOPS_NEED_FIXUP.
	(expand_omp_for_static_nochunk): Handle simple latch bb.  Handle case
	that omp_for already has its own loop struct.
	* tree-parloops.c (create_phi_for_local_result)
	(create_call_for_reduction): Handle simple latch bb.
	(create_parallel_loop): Add simple latch bb to preserve
	LOOPS_HAVE_SIMPLE_LATCHES.  Record new exit.  Handle simple latch bb.
	(gen_parallel_loop): Remove call to cancel_loop_tree.
	(parallelize_loops): Skip loops that are inner loops of parallelized
	loops.
	(pass_parallelize_loops::execute) [ENABLE_CHECKING]: Call
	verify_loop_structure.

From-SVN: r226427

1 files changed, 30 insertions, 2 deletions

diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index 3135606..0f5c0f1 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -5604,6 +5604,10 @@ expand_omp_taskreg (struct omp_region *region)
 	}
       if (gimple_in_ssa_p (cfun))
 	update_ssa (TODO_update_ssa);
+#ifdef ENABLE_CHECKING
+      if (!loops_state_satisfies_p (LOOPS_NEED_FIXUP))
+	verify_loop_structure ();
+#endif
       pop_cfun ();
     }
 
@@ -6535,7 +6539,8 @@ expand_omp_for_static_nochunk (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);
     }
   exit_bb = region->exit;
@@ -6818,6 +6823,11 @@ expand_omp_for_static_nochunk (struct omp_region *region,
   if (!broken_loop)
     {
       ep = find_edge (cont_bb, body_bb);
+      if (ep == NULL)
+	{
+	  ep = BRANCH_EDGE (cont_bb);
+	  gcc_assert (single_succ (ep->dest) == body_bb);
+	}
       if (gimple_omp_for_combined_p (fd->for_stmt))
 	{
 	  remove_edge (ep);
@@ -6843,9 +6853,19 @@ expand_omp_for_static_nochunk (struct omp_region *region,
   set_immediate_dominator (CDI_DOMINATORS, fin_bb,
 			   recompute_dominator (CDI_DOMINATORS, fin_bb));
 
+  struct loop *loop = body_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);
+      return;
+    }
+
   if (!broken_loop && !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;
@@ -8984,6 +9004,10 @@ expand_omp_target (struct omp_region *region)
 	  if (changed)
 	    cleanup_tree_cfg ();
 	}
+#ifdef ENABLE_CHECKING
+      if (!loops_state_satisfies_p (LOOPS_NEED_FIXUP))
+	verify_loop_structure ();
+#endif
       pop_cfun ();
     }
 
@@ -9492,6 +9516,10 @@ execute_expand_omp (void)
 
   expand_omp (root_omp_region);
 
+#ifdef ENABLE_CHECKING
+  if (!loops_state_satisfies_p (LOOPS_NEED_FIXUP))
+    verify_loop_structure ();
+#endif
   cleanup_tree_cfg ();
 
   free_omp_regions ();