stdc_bit_width_ul
return (1UL << (stdc_bit_width_ul(ul) - 1));
return (2UL << (stdc_bit_width_ul(ul - 1) - 1));
.so_ul = stdc_bit_width_ul,
extern unsigned int stdc_bit_width_ul(unsigned long) _C23_UNSEQ_ATTR;