gcc/gcc49-pr62103.patch

51 lines
1.5 KiB
Diff

2014-08-12 Thomas Preud'homme <thomas.preudhomme@arm.com>
PR middle-end/62103
* gimple-fold.c (fold_ctor_reference): Don't fold in presence of
bitfields, that is when size doesn't match the size of type or the
size of the constructor.
* gcc.c-torture/execute/bitfld-6.c: New test.
--- gcc/gimple-fold.c (revision 213845)
+++ gcc/gimple-fold.c (revision 213846)
@@ -4355,8 +4355,10 @@ fold_ctor_reference (tree type, tree cto
result. */
if (!AGGREGATE_TYPE_P (TREE_TYPE (ctor)) && !offset
/* VIEW_CONVERT_EXPR is defined only for matching sizes. */
- && operand_equal_p (TYPE_SIZE (type),
- TYPE_SIZE (TREE_TYPE (ctor)), 0))
+ && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
+ && TREE_CODE (TYPE_SIZE (TREE_TYPE (ctor))) == INTEGER_CST
+ && !compare_tree_int (TYPE_SIZE (type), size)
+ && !compare_tree_int (TYPE_SIZE (TREE_TYPE (ctor)), size))
{
ret = canonicalize_constructor_val (unshare_expr (ctor), from_decl);
ret = fold_unary (VIEW_CONVERT_EXPR, type, ret);
--- gcc/testsuite/gcc.c-torture/execute/bitfld-6.c (revision 0)
+++ gcc/testsuite/gcc.c-torture/execute/bitfld-6.c (revision 213846)
@@ -0,0 +1,23 @@
+union U
+{
+ const int a;
+ unsigned b : 20;
+};
+
+static union U u = { 0x12345678 };
+
+/* Constant folding used to fail to account for endianness when folding a
+ union. */
+
+int
+main (void)
+{
+#ifdef __BYTE_ORDER__
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+ return u.b - 0x45678;
+#else
+ return u.b - 0x12345;
+#endif
+#endif
+ return 0;
+}