Great macro for building bitmask in C

bitmask macro

#include <stdio.h>

#define BITMASK(H,L) ( (2ULL<<(H))-(1ULL<<(L)) )

int main()
{
 printf("bitmask is %08X\n", BITMASK(4,3));
 printf("bitmask is %08X\n", BITMASK(63,0));
 printf("bitmask is %08X\n", BITMASK(63,2));
 printf("bitmask is %08X\n", BITMASK(31,17));
 printf("bitmask is %08X\n", BITMASK(1,0));

 return 0;
}