tree-ssa-ccp.c (ccp_finalize): Return if something changed.

	* tree-ssa-ccp.c (ccp_finalize): Return if something changed.
	(execute_ssa_ccp): Return flags conditionally.
	* tree-ssa-propagate.c (substitue_and_fold): Return if something was
	changed.
	* tree-ssa-propagate.h (substitute_and_fold): Update prototype.

From-SVN: r120894

gcc/ChangeLog

+18-01-2007  Jan Hubicka  <jh@suse.cz>
+
+	* tree-ssa-ccp.c (ccp_finalize): Return if something changed.
+	(execute_ssa_ccp): Return flags conditionally.
+	* tree-ssa-propagate.c (substitue_and_fold): Return if something was
+	changed.
+	* tree-ssa-propagate.h (substitute_and_fold): Update prototype.
+
 18-01-2007  Steven Bosscher  <steven@gcc.gnu.org>
 
 	* cfgcleanup.c (cleanup_cfg): Detect cfglayout mode and set

gcc/tree-ssa-ccp.c

@@ -665,15 +665,18 @@ ccp_initialize (void)
 
 
 /* Do final substitution of propagated values, cleanup the flowgraph and
-   free allocated storage.  */
+   free allocated storage.  
 
-static void
+   Return TRUE when something was optimized.  */
+
+static bool
 ccp_finalize (void)
 {
   /* Perform substitutions based on the known constant values.  */
-  substitute_and_fold (const_val, false);
+  bool something_changed = substitute_and_fold (const_val, false);
 
   free (const_val);
+  return something_changed;;
 }
 
 
@@ -1397,21 +1400,24 @@ ccp_visit_stmt (tree stmt, edge *taken_edge_p, tree *output_p)
 
 /* Main entry point for SSA Conditional Constant Propagation.  */
 
-static void
+static unsigned int
 execute_ssa_ccp (bool store_ccp)
 {
   do_store_ccp = store_ccp;
   ccp_initialize ();
   ssa_propagate (ccp_visit_stmt, ccp_visit_phi_node);
-  ccp_finalize ();
+  if (ccp_finalize ())
+    return (TODO_cleanup_cfg | TODO_update_ssa | TODO_update_smt_usage
+	    | TODO_remove_unused_locals);
+  else
+    return 0;
 }
 
 
 static unsigned int
 do_ssa_ccp (void)
 {
-  execute_ssa_ccp (false);
-  return 0;
+  return execute_ssa_ccp (false);
 }
 
 
@@ -1435,13 +1441,8 @@ struct tree_opt_pass pass_ccp =
   0,					/* properties_provided */
   0,					/* properties_destroyed */
   0,					/* todo_flags_start */
-  TODO_cleanup_cfg
-    | TODO_dump_func
-    | TODO_update_ssa
-    | TODO_ggc_collect
-    | TODO_verify_ssa
-    | TODO_verify_stmts
-    | TODO_update_smt_usage,		/* todo_flags_finish */
+  TODO_dump_func | TODO_verify_ssa
+  | TODO_verify_stmts | TODO_ggc_collect,/* todo_flags_finish */
   0					/* letter */
 };
 
@@ -1450,8 +1451,7 @@ static unsigned int
 do_ssa_store_ccp (void)
 {
   /* If STORE-CCP is not enabled, we just run regular CCP.  */
-  execute_ssa_ccp (flag_tree_store_ccp != 0);
-  return 0;
+  return execute_ssa_ccp (flag_tree_store_ccp != 0);
 }
 
 static bool
@@ -1477,13 +1477,8 @@ struct tree_opt_pass pass_store_ccp =
   0,					/* properties_provided */
   0,					/* properties_destroyed */
   0,					/* todo_flags_start */
-  TODO_dump_func
-    | TODO_update_ssa
-    | TODO_ggc_collect
-    | TODO_verify_ssa
-    | TODO_cleanup_cfg
-    | TODO_verify_stmts
-    | TODO_update_smt_usage,		/* todo_flags_finish */
+  TODO_dump_func | TODO_verify_ssa
+  | TODO_verify_stmts | TODO_ggc_collect,/* todo_flags_finish */
   0					/* letter */
 };
 

gcc/tree-ssa-propagate.c

@@ -1137,15 +1137,18 @@ fold_predicate_in (tree stmt)
    expressions are evaluated with a call to vrp_evaluate_conditional.
    This will only give meaningful results when called from tree-vrp.c
    (the information used by vrp_evaluate_conditional is built by the
-   VRP pass).  */
+   VRP pass).  
 
-void
+   Return TRUE when something changed.  */
+
+bool
 substitute_and_fold (prop_value_t *prop_value, bool use_ranges_p)
 {
   basic_block bb;
+  bool something_changed = false;
 
   if (prop_value == NULL && !use_ranges_p)
-    return;
+    return false;
 
   if (dump_file && (dump_flags & TDF_DETAILS))
     fprintf (dump_file, "\nSubstituing values and folding statements\n\n");
@@ -1234,6 +1237,7 @@ substitute_and_fold (prop_value_t *prop_value, bool use_ranges_p)
 
 	      /* Determine what needs to be done to update the SSA form.  */
 	      pop_stmt_changes (bsi_stmt_ptr (i));
+	      something_changed = true;
 	    }
 	  else
 	    {
@@ -1261,6 +1265,7 @@ substitute_and_fold (prop_value_t *prop_value, bool use_ranges_p)
       fprintf (dump_file, "Predicates folded:    %6ld\n",
 	       prop_stats.num_pred_folded);
     }
+  return something_changed;
 }
 
 #include "gt-tree-ssa-propagate.h"

gcc/tree-ssa-propagate.h

@@ -120,6 +120,6 @@ bool stmt_makes_single_load (tree);
 bool stmt_makes_single_store (tree);
 prop_value_t *get_value_loaded_by (tree, prop_value_t *);
 bool replace_uses_in (tree, bool *, prop_value_t *);
-void substitute_and_fold (prop_value_t *, bool);
+bool substitute_and_fold (prop_value_t *, bool);
 
 #endif /* _TREE_SSA_PROPAGATE_H  */