PR middle-end/29965

	* omp-low.c (determine_parallel_type): Don't try to optimize combined
	parallels if region->exit or region->inner->exit is NULL.
	(expand_omp_parallel): Handle NULL region->exit even if cfg is already
	built.
	(expand_omp_for_generic): Handle NULL region->cond and region->exit.
	(expand_omp_for): Use expand_omp_for_generic if either region->cond
	or region->exit is NULL.
	(expand_omp_sections): Handle NULL region->cond or region->exit.
	(expand_omp_synch): 

	* gcc.dg/gomp/pr29965-1.c: New test.
	* gcc.dg/gomp/pr29965-2.c: New test.
	* gcc.dg/gomp/pr29965-3.c: New test.
	* gcc.dg/gomp/pr29965-4.c: New test.
	* gcc.dg/gomp/pr29965-5.c: New test.
	* gcc.dg/gomp/pr29965-6.c: New test.
	* g++.dg/gomp/pr29965-1.C: New test.
	* g++.dg/gomp/pr29965-2.C: New test.
	* g++.dg/gomp/pr29965-3.C: New test.
	* g++.dg/gomp/pr29965-4.C: New test.
	* g++.dg/gomp/pr29965-5.C: New test.
	* g++.dg/gomp/pr29965-6.C: New test.
	* g++.dg/gomp/pr29965-7.C: New test.
	* g++.dg/gomp/pr29965-8.C: New test.
	* g++.dg/gomp/pr29965-9.C: New test.
	* g++.dg/gomp/pr29965-10.C: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@119483 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 103 insertions, 47 deletions

diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index 0816103f190..30dbc713e8d 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -365,7 +365,8 @@ determine_parallel_type (struct omp_region *region)
   basic_block par_entry_bb, par_exit_bb;
   basic_block ws_entry_bb, ws_exit_bb;
 
-  if (region == NULL || region->inner == NULL)
+  if (region == NULL || region->inner == NULL
+      || region->exit == NULL || region->inner->exit == NULL)
     return;
 
   /* We only support parallel+for and parallel+sections.  */
@@ -2443,7 +2444,6 @@ expand_omp_parallel (struct omp_region *region)
       block_stmt_iterator si;
 
       entry_succ_e = single_succ_edge (entry_bb);
-      exit_succ_e = single_succ_edge (exit_bb);
 
       si = bsi_last (entry_bb);
       gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_PARALLEL);
@@ -2451,7 +2451,11 @@ expand_omp_parallel (struct omp_region *region)
 
       new_bb = entry_bb;
       remove_edge (entry_succ_e);
-      make_edge (new_bb, exit_succ_e->dest, EDGE_FALLTHRU);
+      if (exit_bb)
+	{
+	  exit_succ_e = single_succ_edge (exit_bb);
+	  make_edge (new_bb, exit_succ_e->dest, EDGE_FALLTHRU);
+	}
     }
   else
     {
@@ -2574,10 +2578,11 @@ expand_omp_for_generic (struct omp_region *region,
 			enum built_in_function start_fn,
 			enum built_in_function next_fn)
 {
-  tree l0, l1, l2, l3;
+  tree l0, l1, l2 = NULL, l3 = NULL;
   tree type, istart0, iend0, iend;
   tree t, args, list;
-  basic_block entry_bb, cont_bb, exit_bb, l0_bb, l1_bb, l2_bb, l3_bb;
+  basic_block entry_bb, cont_bb, exit_bb, l0_bb, l1_bb;
+  basic_block l2_bb = NULL, l3_bb = NULL;
   block_stmt_iterator si;
   bool in_combined_parallel = is_combined_parallel (region);
 
@@ -2589,18 +2594,25 @@ expand_omp_for_generic (struct omp_region *region,
   TREE_ADDRESSABLE (istart0) = 1;
   TREE_ADDRESSABLE (iend0) = 1;
 
+  gcc_assert ((region->cont != NULL) ^ (region->exit == NULL));
+
   entry_bb = region->entry;
   l0_bb = create_empty_bb (entry_bb);
   l1_bb = single_succ (entry_bb);
-  cont_bb = region->cont;
-  l2_bb = create_empty_bb (cont_bb);
-  l3_bb = single_succ (cont_bb);
-  exit_bb = region->exit;
 
   l0 = tree_block_label (l0_bb);
   l1 = tree_block_label (l1_bb);
-  l2 = tree_block_label (l2_bb);
-  l3 = tree_block_label (l3_bb);
+
+  cont_bb = region->cont;
+  exit_bb = region->exit;
+  if (cont_bb)
+    {
+      l2_bb = create_empty_bb (cont_bb);
+      l3_bb = single_succ (cont_bb);
+
+      l2 = tree_block_label (l2_bb);
+      l3 = tree_block_label (l3_bb);
+    }
 
   si = bsi_last (entry_bb);
   gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_FOR);
@@ -2626,9 +2638,12 @@ expand_omp_for_generic (struct omp_region *region,
       args = tree_cons (NULL, t, args);
       t = build_function_call_expr (built_in_decls[start_fn], args);
       t = get_formal_tmp_var (t, &list);
-      t = build3 (COND_EXPR, void_type_node, t, build_and_jump (&l0),
-		  build_and_jump (&l3));
-      append_to_statement_list (t, &list);
+      if (cont_bb)
+	{
+	  t = build3 (COND_EXPR, void_type_node, t, build_and_jump (&l0),
+		      build_and_jump (&l3));
+	  append_to_statement_list (t, &list);
+	}
       bsi_insert_after (&si, list, BSI_SAME_STMT);
     }
   bsi_remove (&si, true);
@@ -2646,6 +2661,15 @@ expand_omp_for_generic (struct omp_region *region,
   si = bsi_start (l0_bb);
   bsi_insert_after (&si, list, BSI_CONTINUE_LINKING);
 
+  /* Handle the rare case where BODY doesn't ever return.  */
+  if (cont_bb == NULL)
+    {
+      remove_edge (single_succ_edge (entry_bb));
+      make_edge (entry_bb, l0_bb, EDGE_FALLTHRU);
+      make_edge (l0_bb, l1_bb, EDGE_FALLTHRU);
+      return;
+    }
+
   /* Code to control the increment and predicate for the sequential
      loop goes in the first half of EXIT_BB (we split EXIT_BB so
      that we can inherit all the edges going out of the loop
@@ -3098,7 +3122,10 @@ expand_omp_for (struct omp_region *region)
   extract_omp_for_data (last_stmt (region->entry), &fd);
   region->sched_kind = fd.sched_kind;
 
-  if (fd.sched_kind == OMP_CLAUSE_SCHEDULE_STATIC && !fd.have_ordered)
+  if (fd.sched_kind == OMP_CLAUSE_SCHEDULE_STATIC
+      && !fd.have_ordered
+      && region->cont
+      && region->exit)
     {
       if (fd.chunk_size == NULL)
 	expand_omp_for_static_nochunk (region, &fd);
@@ -3156,15 +3183,28 @@ expand_omp_sections (struct omp_region *region)
 
   entry_bb = region->entry;
   l0_bb = create_empty_bb (entry_bb);
+  l0 = tree_block_label (l0_bb);
+
+  gcc_assert ((region->cont != NULL) ^ (region->exit == NULL));
   l1_bb = region->cont;
-  l2_bb = single_succ (l1_bb);
-  default_bb = create_empty_bb (l1_bb->prev_bb);
-  exit_bb = region->exit;
+  if (l1_bb)
+    {
+      l2_bb = single_succ (l1_bb);
+      default_bb = create_empty_bb (l1_bb->prev_bb);
 
-  l0 = tree_block_label (l0_bb);
-  l1 = tree_block_label (l1_bb);
+      l1 = tree_block_label (l1_bb);
+    }
+  else
+    {
+      l2_bb = create_empty_bb (l0_bb);
+      default_bb = l2_bb;
+
+      l1 = NULL;
+    }
   l2 = tree_block_label (l2_bb);
 
+  exit_bb = region->exit;
+
   v = create_tmp_var (unsigned_type_node, ".section");
 
   /* We will build a switch() with enough cases for all the
@@ -3201,7 +3241,7 @@ expand_omp_sections (struct omp_region *region)
 	      build_int_cst (unsigned_type_node, 0), NULL, l2);
   TREE_VEC_ELT (label_vec, 0) = t;
   make_edge (l0_bb, l2_bb, 0);
-  
+
   /* Convert each OMP_SECTION into a CASE_LABEL_EXPR.  */
   for (inner = region->inner, i = 1; inner; inner = inner->next, ++i)
     {
@@ -3220,15 +3260,19 @@ expand_omp_sections (struct omp_region *region)
       gcc_assert (i < len || OMP_SECTION_LAST (bsi_stmt (si)));
       bsi_remove (&si, true);
 
-      si = bsi_last (s_exit_bb);
-      gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_RETURN);
-      bsi_remove (&si, true);
-
       e = single_pred_edge (s_entry_bb);
       e->flags = 0;
       redirect_edge_pred (e, l0_bb);
 
       single_succ_edge (s_entry_bb)->flags = EDGE_FALLTHRU;
+
+      if (s_exit_bb == NULL)
+	continue;
+
+      si = bsi_last (s_exit_bb);
+      gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_RETURN);
+      bsi_remove (&si, true);
+
       single_succ_edge (s_exit_bb)->flags = EDGE_FALLTHRU;
     }
 
@@ -3244,24 +3288,30 @@ expand_omp_sections (struct omp_region *region)
   bsi_insert_after (&si, t, BSI_CONTINUE_LINKING);
 
   /* Code to get the next section goes in L1_BB.  */
-  si = bsi_last (l1_bb);
-  gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_CONTINUE);
+  if (l1_bb)
+    {
+      si = bsi_last (l1_bb);
+      gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_CONTINUE);
 
-  t = built_in_decls[BUILT_IN_GOMP_SECTIONS_NEXT];
-  t = build_function_call_expr (t, NULL);
-  t = build2 (MODIFY_EXPR, void_type_node, v, t);
-  bsi_insert_after (&si, t, BSI_SAME_STMT);
-  bsi_remove (&si, true);
+      t = built_in_decls[BUILT_IN_GOMP_SECTIONS_NEXT];
+      t = build_function_call_expr (t, NULL);
+      t = build2 (MODIFY_EXPR, void_type_node, v, t);
+      bsi_insert_after (&si, t, BSI_SAME_STMT);
+      bsi_remove (&si, true);
+    }
 
   /* Cleanup function replaces OMP_RETURN in EXIT_BB.  */
-  si = bsi_last (exit_bb);
-  if (OMP_RETURN_NOWAIT (bsi_stmt (si)))
-    t = built_in_decls[BUILT_IN_GOMP_SECTIONS_END_NOWAIT];
-  else
-    t = built_in_decls[BUILT_IN_GOMP_SECTIONS_END];
-  t = build_function_call_expr (t, NULL);
-  bsi_insert_after (&si, t, BSI_SAME_STMT);
-  bsi_remove (&si, true);
+  if (exit_bb)
+    {
+      si = bsi_last (exit_bb);
+      if (OMP_RETURN_NOWAIT (bsi_stmt (si)))
+	t = built_in_decls[BUILT_IN_GOMP_SECTIONS_END_NOWAIT];
+      else
+	t = built_in_decls[BUILT_IN_GOMP_SECTIONS_END];
+      t = build_function_call_expr (t, NULL);
+      bsi_insert_after (&si, t, BSI_SAME_STMT);
+      bsi_remove (&si, true);
+    }
 
   /* Connect the new blocks.  */
   if (is_combined_parallel (region))
@@ -3274,9 +3324,12 @@ expand_omp_sections (struct omp_region *region)
   else
     make_edge (entry_bb, l0_bb, EDGE_FALLTHRU);
 
-  e = single_succ_edge (l1_bb);
-  redirect_edge_succ (e, l0_bb);
-  e->flags = EDGE_FALLTHRU;
+  if (l1_bb)
+    {
+      e = single_succ_edge (l1_bb);
+      redirect_edge_succ (e, l0_bb);
+      e->flags = EDGE_FALLTHRU;
+    }
 }
 
 
@@ -3337,10 +3390,13 @@ expand_omp_synch (struct omp_region *region)
   bsi_remove (&si, true);
   single_succ_edge (entry_bb)->flags = EDGE_FALLTHRU;
 
-  si = bsi_last (exit_bb);
-  gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_RETURN);
-  bsi_remove (&si, true);
-  single_succ_edge (exit_bb)->flags = EDGE_FALLTHRU;
+  if (exit_bb)
+    {
+      si = bsi_last (exit_bb);
+      gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_RETURN);
+      bsi_remove (&si, true);
+      single_succ_edge (exit_bb)->flags = EDGE_FALLTHRU;
+    }
 }