stdc_leading_zeros_ull
return (stdc_leading_zeros_ull(~ull));
return (stdc_leading_zeros_ull(ull) + 1);
.so_ull = stdc_leading_zeros_ull,
extern unsigned int stdc_leading_zeros_ull(unsigned long long) _C23_UNSEQ_ATTR;
char(*)[8]: stdc_leading_zeros_ull(val))