/*
Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002 Free Software Foundation,
Inc.

This file is part of the GNU MP Library.

The GNU MP Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or (at your
option) any later version.

The GNU MP Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
License for more details.

You should have received a copy of the GNU Lesser General Public License
along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA.
*/

#include <stdio.h>
#include "gmp.h"
#include "gmp-impl.h"

#if defined (USG) || defined (__SVR4) || defined (_UNICOS) || defined (__hpux)
#include <time.h>

int
cputime ()
{
  if (CLOCKS_PER_SEC < 100000)
    return clock () * 1000 / CLOCKS_PER_SEC;
  return clock () / (CLOCKS_PER_SEC / 1000);
}
#else
#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>

int
cputime ()
{
  struct rusage rus;

  getrusage (0, &rus);
  return rus.ru_utime.tv_sec * 1000 + rus.ru_utime.tv_usec / 1000;
}
#endif

#define M * 1000000

#ifndef CLOCK
#error "Don't know CLOCK of your machine"
#endif

#ifndef OPS
#define OPS (CLOCK/5)
#endif
#ifndef SIZE
#define SIZE 328
#endif
#ifndef TIMES
#define TIMES OPS/SIZE
#else
#undef OPS
#define OPS (SIZE*TIMES)
#endif


mp_limb_t
refmpn_sub_n (mp_ptr res_ptr,
	      mp_srcptr s1_ptr, mp_srcptr s2_ptr, mp_size_t size)
{
  register mp_limb_t x, y, cy;
  register mp_size_t j;

  /* The loop counter and index J goes from -SIZE to -1.  This way
     the loop becomes faster.  */
  j = -size;

  /* Offset the base pointers to compensate for the negative indices.  */
  s1_ptr -= j;
  s2_ptr -= j;
  res_ptr -= j;

  cy = 0;
  do
    {
      y = s2_ptr[j];
      x = s1_ptr[j];
      y = (y + cy) & GMP_NUMB_MASK;	/* add previous carry to subtrahend */
      cy = (y < cy);			/* get out carry from that addition */
      y = (x - y) & GMP_NUMB_MASK;	/* main subtract */
      cy = (y > x) + cy;		/* get out carry from the subtract, combine */
      res_ptr[j] = y;
    }
  while (++j != 0);

  return cy;
}

main (argc, argv)
     int argc;
     char **argv;
{
  mp_limb_t s1[SIZE];
  mp_limb_t s2[SIZE];
  mp_limb_t dx[SIZE+2];
  mp_limb_t dy[SIZE+2];
  int cyx, cyy;
  int i;
  long t0, t;
  unsigned int test;
  mp_size_t size;
  unsigned int ntests;

  ntests = ~(unsigned) 0;
  if (argc == 2)
    ntests = strtol (argv[1], 0, 0);

  for (test = 1; test <= ntests; test++)
    {
#if TIMES == 1 && ! defined (PRINT)
      if (test % (SIZE > 10000 ? 1 : 10000 / SIZE) == 0)
	{
	  printf ("\r%d", test);
	  fflush (stdout);
	}
#endif

#ifdef RANDOM
      size = random () % SIZE + 1;
#else
      size = SIZE;
#endif

      dx[0] = 0x87654321;
      dy[0] = 0x87654321;
      dx[size+1] = 0x12345678;
      dy[size+1] = 0x12345678;

#if TIMES != 1
      mpn_random (s1, size);
      mpn_random (s2, size);

#ifndef NOCHECK
      t0 = cputime();
      for (i = 0; i < TIMES; i++)
	refmpn_sub_n (dx+1, s1, s2, size);
      t = cputime() - t0;
      printf ("refmpn_sub_n: %5ldms (%.2f cycles/limb)\n",
	      t, ((double) t * CLOCK) / (OPS * 1000.0));
#endif

      t0 = cputime();
      for (i = 0; i < TIMES; i++)
	mpn_sub_n (dx+1, s1, s2, size);
      t = cputime() - t0;
      printf ("mpn_sub_n:    %5ldms (%.2f cycles/limb)\n",
	      t, ((double) t * CLOCK) / (OPS * 1000.0));
#endif

#ifndef NOCHECK
      mpn_random2 (s1, size);
      mpn_random2 (s2, size);

#ifdef PRINT
      mpn_print (s1, size);
      mpn_print (s2, size);
#endif

      /* Put garbage in the destination.  */
      for (i = 0; i < size; i++)
	{
	  dx[i+1] = 0xdead;
	  dy[i+1] = 0xbeef;
	}

      cyx = refmpn_sub_n (dx+1, s1, s2, size);
      cyy = mpn_sub_n (dy+1, s1, s2, size);
#ifdef PRINT
      printf ("%d ", cyx); mpn_print (dx+1, size);
      printf ("%d ", cyy); mpn_print (dy+1, size);
#endif
      if (cyx != cyy || mpn_cmp (dx, dy, size+2) != 0
	  || dx[0] != 0x87654321 || dx[size+1] != 0x12345678)
	{
#ifndef PRINT
	  printf ("%d ", cyx); mpn_print (dx+1, size);
	  printf ("%d ", cyy); mpn_print (dy+1, size);
#endif
	  printf ("\n");
	  if (dy[0] != 0x87654321)
	    printf ("clobbered at low end\n");
	  if (dy[size+1] != 0x12345678)
	    printf ("clobbered at high end\n");
	  printf ("TEST NUMBER %u\n", test);
	  abort();
	}
#endif
    }
}

mpn_print (mp_ptr p, mp_size_t size)
{
  mp_size_t i;

  for (i = size - 1; i >= 0; i--)
    {
#ifdef _LONG_LONG_LIMB
      printf ("%0*lX%0*lX", (int) (sizeof(mp_limb_t)),
	      (unsigned long) (p[i] >> (BITS_PER_MP_LIMB/2)),
              (int) (sizeof(mp_limb_t)), (unsigned long) (p[i]));
#else
      printf ("%0*lX", (int) (2 * sizeof(mp_limb_t)), p[i]);
#endif
#ifdef SPACE
      if (i != 0)
	printf (" ");
#endif
    }
  puts ("");
}
