#include <stdio.h>  

void set_bit(void *base, unsigned long n)

{

    unsigned long *m = (unsigned long*) base;

    unsigned long size = sizeof(unsigned long) * 8;

    m[ n / size ] |= 1UL << (n % size);

}  

void clear_bit(void *base, unsigned long n)

{

    unsigned long *m = (unsigned long*) base;

    unsigned long size = sizeof(unsigned long) * 8;

    m[ n / size ] &= ~(1UL << (n % size));

}  

int main()

{

    unsigned long value[2] = {0};

    set_bit(value, 0);

    set_bit(value, 63);

    printf("Set:\n");

    printf("0x%016lx, 0x%016lx\n", value[0], value[1]);

    clear_bit(value, 0);

    clear_bit(value, 63);

    printf("Clear:\n");

    printf("0x%016lx, 0x%016lx\n", value[0], value[1]);

    return 0;

}