ff_ctzll           97 libavutil/intmath.h #define ff_ctzll(v) __builtin_ctzll(v)
ff_ctzll          126 libavutil/intmath.h #define ff_ctzll ff_ctzll_c
ff_ctzll           55 libavutil/x86/intmath.h #       define ff_ctzll(v) _tzcnt_u64(v)
ff_ctzll           57 libavutil/x86/intmath.h #       define ff_ctzll ff_ctzll_x86