tree-ssa-forwprop.c (forward_propagate_into_cond): Keep track if we simplified anything.

2007-04-27  Richard Guenther  <rguenther@suse.de>

	* tree-ssa-forwprop.c (forward_propagate_into_cond): Keep track
	if we simplified anything.
	(tree_ssa_forward_propagate_single_use_vars): Defer overflow
	warnings until we did a simplification and the stmt was not
	marked as TREE_NO_WARNING.

From-SVN: r124242

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 13803fb..8363fbc 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2007-04-27  Richard Guenther  <rguenther@suse.de>
+
+       * tree-ssa-forwprop.c (forward_propagate_into_cond): Keep track
+       if we simplified anything.
+       (tree_ssa_forward_propagate_single_use_vars): Defer overflow
+       warnings until we did a simplification and the stmt was not
+       marked as TREE_NO_WARNING.
+
 2007-04-27  Mike Stump  <mrs@apple.com>
 
        * config/rs6000/darwin.h (ALWAYS_PUSH_CONSTS_USING_REGS_P): Remove.

diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
index 6d9a467..860a4c4 100644 (file)
--- a/gcc/tree-ssa-forwprop.c
+++ b/gcc/tree-ssa-forwprop.c
@@ -372,9 +372,11 @@ combine_cond_expr_cond (enum tree_code code, tree type,
 /* Propagate from the ssa name definition statements of COND_EXPR
    in statement STMT into the conditional if that simplifies it.  */
 
-static void
+static bool
 forward_propagate_into_cond (tree cond_expr, tree stmt)
 {
+  bool did_something = false;
+
   do {
     tree tmp = NULL_TREE;
     tree cond = COND_EXPR_COND (cond_expr);
@@ -407,7 +409,7 @@ forward_propagate_into_cond (tree cond_expr, tree stmt)
            def_stmt = get_prop_source_stmt (name, false, &single_use_p);
            if (def_stmt == NULL_TREE
                || !can_propagate_from (def_stmt))
-             return;
+             return did_something;
 
            rhs = GIMPLE_STMT_OPERAND (def_stmt, 1);
            tmp = combine_cond_expr_cond (TREE_CODE (cond), boolean_type_node,
@@ -422,7 +424,7 @@ forward_propagate_into_cond (tree cond_expr, tree stmt)
        def_stmt = get_prop_source_stmt (name, true, NULL);
        if (def_stmt == NULL_TREE
            || !can_propagate_from (def_stmt))
-         return;
+         return did_something;
 
        rhs = GIMPLE_STMT_OPERAND (def_stmt, 1);
        tmp = combine_cond_expr_cond (NE_EXPR, boolean_type_node, rhs,
@@ -447,12 +449,16 @@ forward_propagate_into_cond (tree cond_expr, tree stmt)
        /* Remove defining statements.  */
        remove_prop_source_from_use (name, NULL);
 
+       did_something = true;
+
        /* Continue combining.  */
        continue;
       }
 
     break;
   } while (1);
+
+  return did_something;
 }
 
 /* We've just substituted an ADDR_EXPR into stmt.  Update all the 
@@ -986,7 +992,11 @@ tree_ssa_forward_propagate_single_use_vars (void)
                }
               else if (TREE_CODE (rhs) == COND_EXPR)
                 {
-                  forward_propagate_into_cond (rhs, stmt);
+                 bool did_something;
+                 fold_defer_overflow_warnings ();
+                  did_something = forward_propagate_into_cond (rhs, stmt);
+                 fold_undefer_overflow_warnings (!TREE_NO_WARNING (rhs)
+                   && did_something, stmt, WARN_STRICT_OVERFLOW_CONDITIONAL);
                  bsi_next (&bsi);
                 }
              else if (COMPARISON_CLASS_P (rhs))
@@ -1010,7 +1020,12 @@ tree_ssa_forward_propagate_single_use_vars (void)
            }
          else if (TREE_CODE (stmt) == COND_EXPR)
            {
-             forward_propagate_into_cond (stmt, stmt);
+             bool did_something;
+             fold_defer_overflow_warnings ();
+             did_something = forward_propagate_into_cond (stmt, stmt);
+             fold_undefer_overflow_warnings (!TREE_NO_WARNING (stmt)
+                                             && did_something, stmt,
+                                             WARN_STRICT_OVERFLOW_CONDITIONAL);
              bsi_next (&bsi);
            }
          else