PR 22429

[pf3gnuchains/gcc-fork.git] / gcc / fold-const.c

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 16e7eb3..6f829ad 100644 (file)
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -4014,7 +4014,8 @@ build_range_check (tree type, tree exp, int in_p, tree low, tree high)
     }
 
   value = const_binop (MINUS_EXPR, high, low, 0);
-  if (value != 0 && TREE_OVERFLOW (value) && ! TYPE_UNSIGNED (etype))
+  if (value != 0 && (!flag_wrapv || TREE_OVERFLOW (value))
+      && ! TYPE_UNSIGNED (etype))
     {
       tree utype, minv, maxv;
 
@@ -4025,6 +4026,11 @@ build_range_check (tree type, tree exp, int in_p, tree low, tree high)
        case INTEGER_TYPE:
        case ENUMERAL_TYPE:
        case CHAR_TYPE:
+         /* There is no requirement that LOW be within the range of ETYPE
+            if the latter is a subtype.  It must, however, be within the base
+            type of ETYPE.  So be sure we do the subtraction in that type.  */
+         if (TREE_TYPE (etype))
+           etype = TREE_TYPE (etype);
          utype = lang_hooks.types.unsigned_type (etype);
          maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
          maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,