Function gcd

Singular/walk.cc:533–552

* returns gcd of integers a and b * ********************************************************************/

 * returns gcd of integers a and b                                  *
 ********************************************************************/
static inline long gcd(const long a, const long b)
{
  long r, p0 = a, p1 = b;
  //assume(p0 >= 0 && p1 >= 0);
  if(p0 < 0)
  {
    p0 = -p0;
  }
  if(p1 < 0)
  {
    p1 = -p1;
  }
  while(p1 != 0)
  {
    r = p0 % p1;
    p0 = p1;
    p1 = r;
  }
  return p0;
}

/*****************************************************************************
 * compute the gcd of the entries of the vectors curr_weight and diff_weight *