diff options
Diffstat (limited to 'payloads/libpayload/include/libpayload.h')
| -rw-r--r-- | payloads/libpayload/include/libpayload.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/payloads/libpayload/include/libpayload.h b/payloads/libpayload/include/libpayload.h index 781a41d354..c3ca123f1f 100644 --- a/payloads/libpayload/include/libpayload.h +++ b/payloads/libpayload/include/libpayload.h @@ -311,6 +311,13 @@ u8 bin2hex(u8 b); u8 hex2bin(u8 h); void hexdump(const void *memory, size_t length); void fatal(const char *msg) __attribute__ ((noreturn)); + +/* Count Leading Zeroes: clz(0) == 32, clz(0xf) == 28, clz(1 << 31) == 0 */ +static inline int clz(u32 x) { return x ? __builtin_clz(x) : sizeof(x) * 8; } +/* Integer binary logarithm (rounding down): log2(0) == -1, log2(5) == 2 */ +static inline int log2(u32 x) { return sizeof(x) * 8 - clz(x) - 1; } +/* Find First Set: __ffs(0xf) == 0, __ffs(0) == -1, __ffs(1 << 31) == 31 */ +static inline int __ffs(u32 x) { return log2(x & (u32)(-(s32)x)); } /** @} */ |