* expr.c (store_expr_with_bounds): Handle aggregate moves from

	BLKmode.
	* gimple-expr.c (useless_type_conversion_p): Do not use TYPE_CANONICAL
	to define gimple type system; compare aggregates only by size.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@228586 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 15 insertions, 9 deletions

diff --git a/gcc/gimple-expr.c b/gcc/gimple-expr.c
index baed63011fa..2a6ba1aadb9 100644
--- a/gcc/gimple-expr.c
+++ b/gcc/gimple-expr.c
@@ -87,11 +87,6 @@ useless_type_conversion_p (tree outer_type, tree inner_type)
   if (inner_type == outer_type)
     return true;
 
-  /* If we know the canonical types, compare them.  */
-  if (TYPE_CANONICAL (inner_type)
-      && TYPE_CANONICAL (inner_type) == TYPE_CANONICAL (outer_type))
-    return true;
-
   /* Changes in machine mode are never useless conversions unless we
      deal with aggregate types in which case we defer to later checks.  */
   if (TYPE_MODE (inner_type) != TYPE_MODE (outer_type)
@@ -270,12 +265,23 @@ useless_type_conversion_p (tree outer_type, tree inner_type)
       return true;
     }
 
-  /* For aggregates we rely on TYPE_CANONICAL exclusively and require
-     explicit conversions for types involving to be structurally
-     compared types.  */
+  /* For aggregates compare only the size.  Accesses to fields do have
+     a type information by themselves and thus we only care if we can i.e.
+     use the types in move operations.  */
   else if (AGGREGATE_TYPE_P (inner_type)
 	   && TREE_CODE (inner_type) == TREE_CODE (outer_type))
-    return false;
+    return (!TYPE_SIZE (outer_type)
+	    || (TYPE_SIZE (inner_type)
+		&& operand_equal_p (TYPE_SIZE (inner_type),
+				    TYPE_SIZE (outer_type), 0)));
+
+  else if (TREE_CODE (inner_type) == OFFSET_TYPE
+	   && TREE_CODE (outer_type) == OFFSET_TYPE)
+    return useless_type_conversion_p (TREE_TYPE (outer_type),
+				      TREE_TYPE (inner_type))
+	   && useless_type_conversion_p
+	        (TYPE_OFFSET_BASETYPE (outer_type),
+		 TYPE_OFFSET_BASETYPE (inner_type));
 
   return false;
 }