#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "gdtoa.h"

FPI fpi_near = {
  53, 1-1023-53+1, 2046-1023-53+1, 1, 0
};

FPI fpi_zero = {
  53, 1-1023-53+1, 2046-1023-53+1, 0, 0
};

FPI fpi_up = {
  53, 1-1023-53+1, 2046-1023-53+1, 2, 0
};

FPI fpi_down = {
  53, 1-1023-53+1, 2046-1023-53+1, 3, 0
};

typedef __int64 s64;

char * mygdtoa( double d, int mode, int ndigits, FPI * amper_fpi) {
  s64 l = * (s64*)&d;
  int i0 = (int) (l >> 32);
  int i1 = (int) l;
  int m0 = i0 & 0xfffff;
  int e0 = (i0 >> 20) & 0x7ff; 
  int isNeg = i0 < 0;
  int mantissa[2];
  int decpt;
  int kind = STRTOG_Normal;
  char * result;
  char * rve;
  int length;

  if (e0 == 0x7ff) {
    if ((m0 | i1) != 0) {
      return "NaN";
    } else {
      return isNeg ? "-Infinity" : "Infinity";
    }
  }
  if ((m0 | i1 | e0) == 0) {
    return isNeg ? "-0.0" : "0.0";
  }

  if (e0 != 0) m0 |= 0x100000;
  else e0 = 1;

  e0 -= 0x3ff + 52;

  mantissa[0] = i1;
  mantissa[1] = m0;

  
  result = gdtoa(amper_fpi, e0, mantissa, &kind, mode, ndigits, &decpt, &rve);

  length = rve - result;
  return result;
}

test1(double x, int n) {
  printf("near %d %s\n", n, mygdtoa(x,2,n, &fpi_near)); 
  printf("zero %d %s\n", n, mygdtoa(x,2,n, &fpi_zero)); 
  printf("up   %d %s\n", n, mygdtoa(x,2,n, &fpi_up)); 
  printf("down %d %s\n", n, mygdtoa(x,2,n, &fpi_down)); 
  
}

void test (double x) {
  test1(x,1); 
  test1(x,5); 
  test1(x,6); 
  test1(x,7); 
  test1(x,8); 

  test1(-x,5); 
  test1(-x,6); 
  test1(-x,7); 
  test1(-x,8); 

  printf("\n");
}

int main(int argc, char ** argv) {
  test (0.40999995);
  test (0.40444449);
  test (1.5);
  test (2.5);
}