/* Test mpn_divrem_1 and mpn_preinv_divrem_1.

Copyright 2003 Free Software Foundation, Inc.

This file is part of the GNU MP Library test suite.

The GNU MP Library test suite is free software; you can redistribute it

and/or modify it under the terms of the GNU General Public License as

published by the Free Software Foundation; either version 3 of the License,

or (at your option) any later version.

The GNU MP Library test suite 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 General

Public License for more details.

You should have received a copy of the GNU General Public License along with

the GNU MP Library test suite.  If not, see https://www.gnu.org/licenses/.  */

#include <stdio.h>

#include <stdlib.h>

#include "gmp.h"

#include "gmp-impl.h"

#include "tests.h"

void

check_data (void)

{

  static const struct {

    mp_limb_t  n[1];

    mp_size_t  nsize;

    mp_limb_t  d;

    mp_size_t  qxn;

    mp_limb_t  want_q[5];

    mp_limb_t  want_r;

  } data[] = {

    { { 0 }, 1, 1, 0,

      { 0 }, 0},

    { { 5 }, 1, 2, 0,

      { 2 }, 1},

    /* Exercises the q update in the nl == constant 0 case of

       udiv_qrnnd_preinv3. Test case copied from t-fat.c. */

    { { 287 }, 1, 7, 1,

      { 0, 41 }, 0 },

#if GMP_NUMB_BITS == 32

    { { 0x3C }, 1, 0xF2, 1,

      { 0x3F789854, 0 }, 0x98 },

#endif

#if GMP_NUMB_BITS == 64

    { { 0x3C }, 1, 0xF2, 1,

      { CNST_LIMB(0x3F789854A0CB1B81), 0 }, 0x0E },

    /* This case exposed some wrong code generated by SGI cc on mips64 irix

       6.5 with -n32 -O2, in the fractional loop for normalized divisor

       using udiv_qrnnd_preinv.  A test "x>al" in one of the sub_ddmmss

       expansions came out wrong, leading to an incorrect quotient.  */

    { { CNST_LIMB(0x3C00000000000000) }, 1, CNST_LIMB(0xF200000000000000), 1,

      { CNST_LIMB(0x3F789854A0CB1B81), 0 }, CNST_LIMB(0x0E00000000000000) },

#endif

  };

  mp_limb_t  dinv, got_r, got_q[numberof(data[0].want_q)];

  mp_size_t  qsize;

  int        i, shift;

  for (i = 0; i < numberof (data); i++)

    {

      qsize = data[i].nsize + data[i].qxn;

      ASSERT_ALWAYS (qsize <= numberof (got_q));

      got_r = mpn_divrem_1 (got_q, data[i].qxn, data[i].n, data[i].nsize,

                            data[i].d);

      if (got_r != data[i].want_r

          || refmpn_cmp (got_q, data[i].want_q, qsize) != 0)

        {

          printf        ("mpn_divrem_1 wrong at data[%d]\n", i);

        bad:

          mpn_trace     ("  n", data[i].n, data[i].nsize);

          printf        ("  nsize=%ld\n", (long) data[i].nsize);

          mp_limb_trace ("  d", data[i].d);

          printf        ("  qxn=%ld\n", (long) data[i].qxn);

          mpn_trace     ("  want q", data[i].want_q, qsize);

          mpn_trace     ("  got  q", got_q, qsize);

          mp_limb_trace ("  want r", data[i].want_r);

          mp_limb_trace ("  got  r", got_r);

          abort ();

        }

      /* test if available */

#if USE_PREINV_DIVREM_1 || HAVE_NATIVE_mpn_preinv_divrem_1

      shift = refmpn_count_leading_zeros (data[i].d);

      dinv = refmpn_invert_limb (data[i].d << shift);

      got_r = mpn_preinv_divrem_1 (got_q, data[i].qxn,

                                   data[i].n, data[i].nsize,

                                   data[i].d, dinv, shift);

      if (got_r != data[i].want_r

          || refmpn_cmp (got_q, data[i].want_q, qsize) != 0)

        {

          printf        ("mpn_preinv divrem_1 wrong at data[%d]\n", i);

          printf        ("  shift=%d\n", shift);

          mp_limb_trace ("  dinv", dinv);

          goto bad;

        }

#endif

    }

}

int

main (void)

{

  tests_start ();

  mp_trace_base = -16;

  check_data ();

  tests_end ();

  exit (0);

}