tree-nested.c (convert_all_function_calls): Iterate until after the sum of…

tree-nested.c (convert_all_function_calls): Iterate until after the sum of static chains in the nest doesn't change.

	* tree-nested.c (convert_all_function_calls): Iterate until after the
	sum of static chains in the nest doesn't change.

From-SVN: r163698

gcc/ChangeLog

+2010-08-31  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* tree-nested.c (convert_all_function_calls): Iterate until after the
+	sum of static chains in the nest doesn't change.
+
 2010-08-31  Anatoly Sokolov  <aesok@post.ru>
 
 	* config/m32c/m32c.c (classes_intersect): Remove.

gcc/testsuite/ChangeLog

+2010-08-31  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc.dg/nested-func-8.c: New test.
+
 2010-08-31  Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>
 
 	PR fortran/38282

gcc/testsuite/gcc.dg/nested-func-8.c

+/* { dg-do run } */
+/* { dg-options "-O -fno-inline" } */
+
+extern void abort (void);
+
+/* Return 0 and clobber the static chain.  */
+
+int
+zero (int n)
+{
+  int
+  nested (int m)
+  {
+    return m - n;
+  }
+
+  return nested (n);
+}
+
+/* Return the triple of ARG in a convoluted manner.  */
+
+int
+triple (int arg)
+{
+  int
+  read_arg (void)
+  {
+    return arg;
+  }
+
+  int
+  parent (int nested_arg)
+  {
+    int
+    child1 (void)
+    {
+      return parent (zero (5));
+    }
+
+    int
+    child2 (void)
+    {
+      return nested_arg + read_arg ();
+    }
+
+    return (nested_arg == 0 ? 0 : child1 ()) + child2 ();
+  }
+
+  return parent (arg);
+}
+
+int main(void)
+{
+  if (triple (13) != 3 * 13)
+    abort ();
+  return 0;
+}

gcc/tree-nested.c

@@ -2070,9 +2070,8 @@ convert_gimple_call (gimple_stmt_iterator *gsi, bool *handled_ops_p,
 static void
 convert_all_function_calls (struct nesting_info *root)
 {
+  unsigned int chain_count = 0, old_chain_count, iter_count;
   struct nesting_info *n;
-  int iter_count;
-  bool any_changed;
 
   /* First, optimistically clear static_chain for all decls that haven't
      used the static chain already for variable access.  */
@@ -2088,6 +2087,7 @@ convert_all_function_calls (struct nesting_info *root)
 	}
       else
 	DECL_STATIC_CHAIN (decl) = 1;
+      chain_count += DECL_STATIC_CHAIN (decl);
     }
 
   /* Walk the functions and perform transformations.  Note that these
@@ -2100,7 +2100,8 @@ convert_all_function_calls (struct nesting_info *root)
   iter_count = 0;
   do
     {
-      any_changed = false;
+      old_chain_count = chain_count;
+      chain_count = 0;
       iter_count++;
 
       if (dump_file && (dump_flags & TDF_DETAILS))
@@ -2109,22 +2110,16 @@ convert_all_function_calls (struct nesting_info *root)
       FOR_EACH_NEST_INFO (n, root)
 	{
 	  tree decl = n->context;
-	  bool old_static_chain = DECL_STATIC_CHAIN (decl);
-
 	  walk_function (convert_tramp_reference_stmt,
 			 convert_tramp_reference_op, n);
 	  walk_function (convert_gimple_call, NULL, n);
-
-	  /* If a call to another function created the use of a chain
-	     within this function, we'll have to continue iteration.  */
-	  if (!old_static_chain && DECL_STATIC_CHAIN (decl))
-	    any_changed = true;
+	  chain_count += DECL_STATIC_CHAIN (decl);
 	}
     }
-  while (any_changed);
+  while (chain_count != old_chain_count);
 
   if (dump_file && (dump_flags & TDF_DETAILS))
-    fprintf (dump_file, "convert_all_function_calls iterations: %d\n\n",
+    fprintf (dump_file, "convert_all_function_calls iterations: %u\n\n",
 	     iter_count);
 }