github.com/afumu/libc@v0.0.6/musl/src/misc/ffsll.c (about)

     1  #include <strings.h>
     2  #include "atomic.h"
     3  
     4  int ffsll(long long i)
     5  {
     6  	return i ? a_ctz_64(i)+1 : 0;
     7  }