/*
 * $Id: testlog.c 70576 2014-06-22 19:31:05Z vinc17/xvii $
 *
 * Test the result of the log() function. Shows a regression in the
 * generic log() function in the glibc (as used on the PowerPC):
 *   https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=210400
 * Now fixed.
 */

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

void out (double x, char *s)
{
  int exp;
  long long m;

  m = frexp (x, &exp) * 9007199254740992LL;
  printf ("%s = %-23.17g (mant: %lld/2^53, exp: %d)\n", s, x, m, exp);
}

int main (int argc, char *argv[])
{
  double x, y;

  if (argc != 2)
    {
      fprintf (stderr, "Usage: testlog <double>\n");
      exit (1);
    }

  x = atof (argv[1]);
  y = log (x);

  out (x, "     x");
  out (y, "log(x)");

  return 0;
}