cfgrtl.c (delete_insn_and_edges, [...]): New.

	* cfgrtl.c (delete_insn_and_edges, delete_insn_chain_and_edges): New.
	* rtl.h (delete_insn_and_edges, delete_insn_chain_and_edges): Declare

	* basic-block.h (update_life_info, update_life_info_in_dirty_blocks,
	delete_noop_moves): Return indeger.
	* flow.c (ndead): New variable.
	(propagate_block_delete_insn): Use delete_insn_and_edges; remove
	BB argument; update callers.
	(propagate_block_delete_libcall): Use delete_insn_chain_and_edges.
	(life_analysis): Do not call purge_all_dead_edges.
	(update_life_info): Return number of deleted insns; print statistics.
	(update_life_info_in_dirty_blocks): likewise.
	(delete_noop_moves): Use delete_insn_and_edges; print statistics;
	return number of insns deleted.

	* cse.c: Include timevar.h
	(delete_trivially_dead_insns): Kill preserve_basic_blocks argument;
	iterate until stabilizes; print statistics; return number of killed
	insns.
	* Makefile.in: (cse.o): Add timevar.h dependency
	* rtl.h (delete_trivially_dead_insns): New.
	* timever.def: Add TV_DELETE_TRIVIALLY_DEAD timer.
	* toplev.c (rest_of_compilation): Update callers.

	* cfgcleanup.c (try_optimize_cfg): Kill blocks.
	(try_optimize_cfg): Do not update liveness.
	(cleanup-cfg): Loop until try_optimize_cfg and dead code
	removal stabilizes; use delete_trivially_dead_insns.

	* cfgrtl.c (verify_flow_info): Sanity check outgoing edges.

From-SVN: r50355

1 files changed, 33 insertions, 9 deletions

diff --git a/gcc/cfgcleanup.c b/gcc/cfgcleanup.c
index 017a4aa..a4dccbe 100644
--- a/gcc/cfgcleanup.c
+++ b/gcc/cfgcleanup.c
@@ -1510,7 +1510,6 @@ try_optimize_cfg (mode)
   bool changed_overall = false;
   bool changed;
   int iterations = 0;
-  sbitmap blocks;
 
   if (mode & CLEANUP_CROSSJUMP)
     add_noreturn_fake_exit_edges ();
@@ -1673,11 +1672,6 @@ try_optimize_cfg (mode)
   if (mode & CLEANUP_CROSSJUMP)
     remove_fake_edges ();
 
-  if ((mode & CLEANUP_UPDATE_LIFE) && changed_overall)
-    update_life_info_in_dirty_blocks (UPDATE_LIFE_GLOBAL,
-				      PROP_DEATH_NOTES | PROP_SCAN_DEAD_CODE
-				      | PROP_KILL_DEAD_CODE | PROP_LOG_LINKS);
-
   for (i = 0; i < n_basic_blocks; i++)
     BASIC_BLOCK (i)->aux = NULL;
 
@@ -1720,9 +1714,39 @@ cleanup_cfg (mode)
   bool changed = false;
 
   timevar_push (TV_CLEANUP_CFG);
-  changed = delete_unreachable_blocks ();
-  if (try_optimize_cfg (mode))
-    delete_unreachable_blocks (), changed = true;
+  if (delete_unreachable_blocks ())
+    {
+      changed = true;
+      /* We've possibly created trivially dead code.  Cleanup it right
+	 now to introduce more oppurtunities for try_optimize_cfg.  */
+      if (!(mode & (CLEANUP_UPDATE_LIFE | CLEANUP_PRE_SIBCALL))
+	  && !reload_completed)
+	delete_trivially_dead_insns (get_insns(), max_reg_num ());
+    }
+  while (try_optimize_cfg (mode))
+    {
+      delete_unreachable_blocks (), changed = true;
+      if (mode & CLEANUP_UPDATE_LIFE)
+	{
+	  /* Cleaning up CFG introduces more oppurtunities for dead code
+	     removal that in turn may introduce more oppurtunities for
+	     cleaning up the CFG.  */
+	  if (!update_life_info_in_dirty_blocks (UPDATE_LIFE_GLOBAL,
+						 PROP_DEATH_NOTES
+						 | PROP_SCAN_DEAD_CODE
+						 | PROP_KILL_DEAD_CODE
+						 | PROP_LOG_LINKS))
+	    break;
+	}
+      else if (!(mode & CLEANUP_PRE_SIBCALL) && !reload_completed)
+	{
+	  if (!delete_trivially_dead_insns (get_insns(), max_reg_num ()))
+	    break;
+	}
+      else
+	break;
+      delete_dead_jumptables ();
+    }
 
   /* Kill the data we won't maintain.  */
   free_EXPR_LIST_list (&label_value_list);