#include "libwasm.h"

#define EULER 2.7182818284
#define EPS   1.0e-9

double exp(const double a) {
  if (a < 0.0) return 1.0 / exp (-a);
  int ip = a;
  const double dp = a - ip;
  double result = 1.0, m = dp, f = 1.0, s = 1.0;
  for (;;) {
    const double e = m / f;
    result += e;
    if (e < EPS) break;
    m *= dp;
    s += 1.0;
    f *= s;
  }
  m = EULER;
  for (;;) {
    const int n = ip & 1;
    if (n) result *= m;
    ip >>= 1;
    if (!ip) break;
    m *= m;
  }
  return result;
}
double fabs (const double a) {
  if (a < 0.0) return -a;
  return a;
}
double sqrt(const double a) {
  if (a <= 0.0) return 0;
  double x = a;
  double root;
  while (1) {
    root = 0.5 * (x + (a / x));
    if (fabs(root - x) < EPS)  break;
    x = root;
  }
  return root;
}