diff options
-rw-r--r-- | src/bit.h | 3 | ||||
-rw-r--r-- | tests/bit.c | 3 |
2 files changed, 5 insertions, 1 deletions
@@ -350,7 +350,8 @@ UINT_OVERLOADS(FIRST_TRAILING_ONE) #define HAS_SINGLE_BIT(type, suffix, width) \ static inline bool has_single_bit##suffix(type n) { \ - return n && !(n & (n - 1)); \ + /** Branchless n && !(n & (n - 1)) */ \ + return n < (n ^ (n - 1)) + 1; \ } UINT_OVERLOADS(ROTATE_LEFT) diff --git a/tests/bit.c b/tests/bit.c index cb339f4..7b20770 100644 --- a/tests/bit.c +++ b/tests/bit.c @@ -117,5 +117,8 @@ int main(void) { verify_eq(bit_floor(0), 0); verify_eq(bit_ceil(0), 1); + bfs_verify(!has_single_bit(0)); + bfs_verify(!has_single_bit(UINT32_MAX)); + return EXIT_SUCCESS; } |