@@ -1181,14 +1181,7 @@ static void __init test_bitmap_const_eval(void)
* in runtime.
*/
- /*
- * Equals to `unsigned long bitmap[1] = { GENMASK(6, 5), }`.
- * Clang on s390 optimizes bitops at compile-time as intended, but at
- * the same time stops treating @bitmap and @bitopvar as compile-time
- * constants after regular test_bit() is executed, thus triggering the
- * build bugs below. So, call const_test_bit() there directly until
- * the compiler is fixed.
- */
+ /* Equals to `unsigned long bitmap[1] = { GENMASK(6, 5), }` */
bitmap_clear(bitmap, 0, BITS_PER_LONG);
if (!test_bit(7, bitmap))
bitmap_set(bitmap, 5, 2);
@@ -1220,6 +1213,15 @@ static void __init test_bitmap_const_eval(void)
/* ~BIT(25) */
BUILD_BUG_ON(!__builtin_constant_p(~var));
BUILD_BUG_ON(~var != ~BIT(25));
+
+ /* ~BIT(25) | BIT(25) == ~0UL */
+ bitmap_complement(&var, &var, BITS_PER_LONG);
+ __assign_bit(25, &var, true);
+
+ /* !(~(~0UL)) == 1 */
+ res = bitmap_full(&var, BITS_PER_LONG);
+ BUILD_BUG_ON(!__builtin_constant_p(res));
+ BUILD_BUG_ON(!res);
}
static void __init selftest(void)
Commit dc34d5036692 ("lib: test_bitmap: add compile-time optimization/evaluations assertions") initially missed __assign_bit(), which led to that quite a time passed before I realized it doesn't get optimized at compilation time. Now that it does, add test for that just to make sure nothing will break one day. To make things more interesting, use bitmap_complement() and bitmap_full(), thus checking their compile-time evaluation as well. And remove the misleading comment mentioning the workaround removed recently in favor of adding the whole file to GCov exceptions. Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> --- lib/test_bitmap.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)