foldaddr-3.c: New file.

	* gcc.dg/tree-ssa/foldaddr-3.c: New file.

	* tree-ssa-ccp (maybe_fold_offset_to_component_ref): Recurse into
	multiple fields of union.

From-SVN: r123674

gcc/ChangeLog

+2007-04-09  Jan Hubicka  <jh@suse.cz>
+
+	* tree-ssa-ccp (maybe_fold_offset_to_component_ref): Recurse into
+	multiple fields of union.
+
 2007-04-09  Zdenek Dvorak  <dvorakz@suse.cz>
 
 	* cfgloopmanip.c (create_preheader): Do not use loop_preheader_edge.

gcc/testsuite/ChangeLog

+2007-04-09  Jan Hubicka  <jh@suse.cz>
+
+	* gcc.dg/tree-ssa/foldaddr-3.c: New file.
+
 2007-04-08  Jan Hubicka  <jh@suse.cz>
 
 	* gcc.dg/tree-ssa/foldaddr-2.c: New file.

gcc/testsuite/gcc.dg/tree-ssa/foldaddr-3.c

+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-tree-optimized" } */
+union a
+{
+  struct s1
+  {
+    long long a;
+    long long b;
+  } s1;
+  struct s2
+  {
+    int c;
+    int d;
+  } s2;
+  struct s3
+  {
+    unsigned long long e;
+    unsigned long long f;
+  } s3;
+} a;
+int *
+t ()
+{
+  return (int *) &a;
+}
+
+/* { dg-final { scan-tree-dump "a.s2.c" "optimized"} } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */

gcc/tree-ssa-ccp.c

@@ -1648,6 +1648,8 @@ maybe_fold_offset_to_component_ref (tree record_type, tree base, tree offset,
 				    tree orig_type, bool base_is_ptr)
 {
   tree f, t, field_type, tail_array_field, field_offset;
+  tree ret;
+  tree new_base;
 
   if (TREE_CODE (record_type) != RECORD_TYPE
       && TREE_CODE (record_type) != UNION_TYPE
@@ -1719,8 +1721,20 @@ maybe_fold_offset_to_component_ref (tree record_type, tree base, tree offset,
 
       /* If we matched, then set offset to the displacement into
 	 this field.  */
-      offset = t;
-      goto found;
+      if (base_is_ptr)
+	new_base = build1 (INDIRECT_REF, record_type, base);
+      else
+	new_base = base;
+      new_base = build3 (COMPONENT_REF, field_type, new_base, f, NULL_TREE);
+
+      /* Recurse to possibly find the match.  */
+      ret = maybe_fold_offset_to_array_ref (new_base, t, orig_type);
+      if (ret)
+	return ret;
+      ret = maybe_fold_offset_to_component_ref (field_type, new_base, t,
+						orig_type, false);
+      if (ret)
+	return ret;
     }
 
   if (!tail_array_field)
@@ -1730,7 +1744,6 @@ maybe_fold_offset_to_component_ref (tree record_type, tree base, tree offset,
   field_type = TREE_TYPE (f);
   offset = int_const_binop (MINUS_EXPR, offset, byte_position (f), 1);
 
- found:
   /* If we get here, we've got an aggregate field, and a possibly 
      nonzero offset into them.  Recurse and hope for a valid match.  */
   if (base_is_ptr)