re PR middle-end/38505 (Revision 142061 caused ICE on __builtin_memcpy)

	PR middle-end/38505
	* tree-ssa-ccp.c (may_propagate_address_into_dereference): Return
	false if ADDR's operand has incomplete type.

	Revert:
	2008-12-15  Jakub Jelinek  <jakub@redhat.com>
	PR middle-end/38505
	* tree-ssa.c (useless_type_conversion_p_1): Return
	false if inner_type is incomplete and outer_type is complete.

From-SVN: r142972

gcc/ChangeLog

 2008-12-31  Jakub Jelinek  <jakub@redhat.com>
 
+	PR middle-end/38505
+	* tree-ssa-ccp.c (may_propagate_address_into_dereference): Return
+	false if ADDR's operand has incomplete type.
+
+	Revert:
+	2008-12-15  Jakub Jelinek  <jakub@redhat.com>
+	PR middle-end/38505
+	* tree-ssa.c (useless_type_conversion_p_1): Return
+	false if inner_type is incomplete and outer_type is complete.
+
+2008-12-31  Jakub Jelinek  <jakub@redhat.com>
+
 	PR middle-end/38676
 	* gimplify.c (gimple_regimplify_operands): For GIMPLE_SWITCH
 	only regimplify switch index.

gcc/tree-ssa-ccp.c

@@ -860,6 +860,10 @@ may_propagate_address_into_dereference (tree addr, tree deref)
   gcc_assert (INDIRECT_REF_P (deref)
 	      && TREE_CODE (addr) == ADDR_EXPR);
 
+  /* Don't propagate if ADDR's operand has incomplete type.  */
+  if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_OPERAND (addr, 0))))
+    return false;
+
   /* If the address is invariant then we do not need to preserve restrict
      qualifications.  But we do need to preserve volatile qualifiers until
      we can annotate the folded dereference itself properly.  */

gcc/tree-ssa.c

@@ -1188,11 +1188,6 @@ useless_type_conversion_p_1 (tree outer_type, tree inner_type)
       if (TREE_CODE (inner_type) != TREE_CODE (outer_type))
 	return false;
 
-      /* Conversion from an incomplete to a complete type is never
-	 useless.  */
-      if (!COMPLETE_TYPE_P (inner_type) && COMPLETE_TYPE_P (outer_type))
-	return false;
-
       /* ???  This seems to be necessary even for aggregates that don't
 	 have TYPE_STRUCTURAL_EQUALITY_P set.  */