src/big_endian.c


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#include "big_endian.h"

void to_big_endian(uint64_t num, unsigned char *result)
{
  *(result+0) = (num >> 56) & 0xff;
  *(result+1) = (num >> 48) & 0xff;
  *(result+2) = (num >> 40) & 0xff;
  *(result+3) = (num >> 32) & 0xff;
  *(result+4) = (num >> 24) & 0xff;
  *(result+5) = (num >> 16) & 0xff;
  *(result+6) = (num >>  8) & 0xff;
  *(result+7) = (num >>  0) & 0xff;
}

uint64_t from_big_endian(unsigned char *num)
{
  uint64_t result = ((uint64_t) (*num) << 56);
  
  result += ((uint64_t) (*(num+1)) << 48);
  result += ((uint64_t) (*(num+2)) << 40);
  result += ((uint64_t) (*(num+3)) << 32);
  result += ((uint64_t) (*(num+4)) << 24);
  result += ((uint64_t) (*(num+5)) << 16);
  result += ((uint64_t) (*(num+6)) <<  8);
  result += ((uint64_t) (*(num+7)) <<  0);

  return result;
}