trans.c (gnat_to_gnu): Remove the padding structure more often.

2007-10-15  Tristan Gingold  <gingold@adacore.com>

	* trans.c (gnat_to_gnu): Remove the padding structure more often.
	This optimize assignment to over-aligned record.

From-SVN: r129339

diff --git a/gcc/ada/trans.c b/gcc/ada/trans.c
index 04729f7b4b14517b8f2a70986f8b7c7c7d967087..65d45b04da0e61485916d7178d3fb6df9e91bbea 100644 (file)
--- a/gcc/ada/trans.c
+++ b/gcc/ada/trans.c
@@ -4810,15 +4810,16 @@ gnat_to_gnu (Node_Id gnat_node)
           && !(TREE_CODE (gnu_result_type) == RECORD_TYPE
                && TYPE_JUSTIFIED_MODULAR_P (gnu_result_type))))
     {
-      /* In this case remove padding only if the inner object is of
-        self-referential size: in that case it must be an object of
-        unconstrained type with a default discriminant.  In other cases,
-        we want to avoid copying too much data.  */
+      /* In this case remove padding only if the inner object type is the
+        same as gnu_result_type or is of self-referential size (in that later
+        case it must be an object of unconstrained type with a default
+        discriminant).  We want to avoid copying too much data.  */
       if (TREE_CODE (TREE_TYPE (gnu_result)) == RECORD_TYPE
          && TYPE_IS_PADDING_P (TREE_TYPE (gnu_result))
-         && CONTAINS_PLACEHOLDER_P (TYPE_SIZE
-                                    (TREE_TYPE (TYPE_FIELDS
-                                                (TREE_TYPE (gnu_result))))))
+         && (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_result)))
+                         == gnu_result_type
+             || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS
+                                            (TREE_TYPE (gnu_result)))))))
        gnu_result = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_result))),
                              gnu_result);
     }