#include <float.h>
#include <ieee754.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>

int main(void) {
 union ieee754_double val;
 uint64_t bits;
 
 val.d = DBL_MAX;
 
 bits = ((uint64_t) val.ieee.negative) << 63
   | ((uint64_t) val.ieee.exponent) << 52
   | ((uint64_t) val.ieee.mantissa0) << 32
   | ((uint64_t) val.ieee.mantissa1);

 printf("%llx\n", bits);

 exit(EXIT_SUCCESS);
}