ff_ctz             94 libavutil/intmath.h #define ff_ctz(v) __builtin_ctz(v)
ff_ctz            106 libavutil/intmath.h #define ff_ctz ff_ctz_c
ff_ctz             52 libavutil/x86/intmath.h #   define ff_ctz(v) _tzcnt_u32(v)