(pointer_int_sum): Don't distribute if intop is unsigned and not the

same size as ptrop.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@10186 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c
index 4e41e5f..b16a7bf 100644 (file)
--- a/gcc/c-typeck.c
+++ b/gcc/c-typeck.c
@@ -2648,7 +2648,13 @@ pointer_int_sum (resultcode, ptrop, intop)
       && TREE_CONSTANT (size_exp)
       /* If the constant comes from pointer subtraction,
         skip this optimization--it would cause an error.  */
-      && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE)
+      && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE
+      /* If the constant is unsigned, and smaller than the pointer size,
+        then we must skip this optimization.  This is because it could cause
+        an overflow error if the constant is negative but INTOP is not.  */
+      && (! TREE_UNSIGNED (TREE_TYPE (intop))
+         || (TYPE_PRECISION (TREE_TYPE (intop))
+             == TYPE_PRECISION (TREE_TYPE (ptrop)))))
     {
       enum tree_code subcode = resultcode;
       tree int_type = TREE_TYPE (intop);