* basic-block.h (force_nonfallthru): Move to...

	* cfghooks.h (struct cfg_hooks): Add force_nonfallthru hook.
	(force_nonfallthru): ...here.
	* cfghooks.c (force_nonfallthru): New function.
	* cfgrtl.c (force_nonfallthru): Rename into...
	(rtl_force_nonfallthru): ...this.
	(commit_one_edge_insertion): Do not set AUX field.
	(commit_edge_insertions): Do not discover new basic blocks.
	(rtl_cfg_hooks): Add rtl_force_nonfallthru.
	(cfg_layout_rtl_cfg_hooks): Likewise.
	* function.c (thread_prologue_and_epilogue_insns): Remove bogus
	ATTRIBUTE_UNUSED.  Discover new basic blocks in the prologue insns.
	* tree-cfg.c (gimple_cfg_hooks): Add NULL for force_nonfallthru.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@172128 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 39 insertions, 2 deletions

diff --git a/gcc/cfghooks.c b/gcc/cfghooks.c
index fb991a76171..34685f4444a 100644
--- a/gcc/cfghooks.c
+++ b/gcc/cfghooks.c
@@ -398,8 +398,7 @@ redirect_edge_and_branch_force (edge e, basic_block dest)
     rescan_loop_exit (e, false, true);
 
   ret = cfg_hooks->redirect_edge_and_branch_force (e, dest);
-  if (ret != NULL
-      && dom_info_available_p (CDI_DOMINATORS))
+  if (ret != NULL && dom_info_available_p (CDI_DOMINATORS))
     set_immediate_dominator (CDI_DOMINATORS, ret, src);
 
   if (current_loops != NULL)
@@ -820,6 +819,8 @@ make_forwarder_block (basic_block bb, bool (*redirect_edge_p) (edge),
   return fallthru;
 }
 
+/* Try to make the edge fallthru.  */
+
 void
 tidy_fallthru_edge (edge e)
 {
@@ -874,6 +875,42 @@ tidy_fallthru_edges (void)
     }
 }
 
+/* Edge E is assumed to be fallthru edge.  Emit needed jump instruction
+   (and possibly create new basic block) to make edge non-fallthru.
+   Return newly created BB or NULL if none.  */
+
+basic_block
+force_nonfallthru (edge e)
+{
+  basic_block ret, src = e->src, dest = e->dest;
+  struct loop *loop;
+
+  if (!cfg_hooks->force_nonfallthru)
+    internal_error ("%s does not support force_nonfallthru",
+		    cfg_hooks->name);
+
+  if (current_loops != NULL)
+    rescan_loop_exit (e, false, true);
+
+  ret = cfg_hooks->force_nonfallthru (e);
+  if (ret != NULL && dom_info_available_p (CDI_DOMINATORS))
+    set_immediate_dominator (CDI_DOMINATORS, ret, src);
+
+  if (current_loops != NULL)
+    {
+      if (ret != NULL)
+	{
+	  loop = find_common_loop (single_pred (ret)->loop_father,
+				   single_succ (ret)->loop_father);
+	  add_bb_to_loop (ret, loop);
+	}
+      else if (find_edge (src, dest) == e)
+	rescan_loop_exit (e, true, false);
+    }
+
+  return ret;
+}
+
 /* Returns true if we can duplicate basic block BB.  */
 
 bool