util: Add L_BITS_{SET|CLEAR}

These macros can set or clear an arbitrary number of bits in a single
call, as follows:

	uint64_t bitmap = 0;

	L_BITS_CLEAR(&bitmap, 0, 1, 5, 15, 32, 63);

1 files changed, 14 insertions, 0 deletions

diff --git a/ell/util.h b/ell/util.h
index 6283296c..f4fc4d11 100644
--- a/ell/util.h
+++ b/ell/util.h
@@ -396,6 +396,20 @@ inline __attribute__((always_inline)) void _l_close_cleanup(void *p)
 	(*_offset & _L_BIT_TO_MASK(_offset, _nr)) != 0;			\
 })
 
+#define L_BITS_SET(bits, ...) __extension__ ({				\
+	const unsigned int __elems[] = {__VA_ARGS__};			\
+	size_t __i;							\
+	for (__i = 0; __i < L_ARRAY_SIZE(__elems); __i++)		\
+		L_BIT_SET(bits, __elems[__i]);				\
+})
+
+#define L_BITS_CLEAR(bits, ...) __extension__ ({			\
+	const unsigned int __elems[] = {__VA_ARGS__};			\
+	size_t __i;							\
+	for (__i = 0; __i < L_ARRAY_SIZE(__elems); __i++)		\
+		L_BIT_CLEAR(bits, __elems[__i]);			\
+})
+
 /*
  * Taken from https://github.com/chmike/cst_time_memcmp, adding a volatile to
  * ensure the compiler does not try to optimize the constant time behavior.