t-trunc.c

a very popular packet of cryptography tools,it encloses the most common used algorithm and protocols

/* Test mpf_trunc, mpf_ceil, mpf_floor.

Copyright 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 <stdlib.h>
#include "gmp.h"
#include "gmp-impl.h"
#include "tests.h"


void
check_print (mpf_srcptr src, mpf_srcptr got, mpf_srcptr want)
{
  mp_trace_base = 16;
  mpf_trace ("src ", src);
  mpf_trace ("got ", got);
  mpf_trace ("want", want);

  printf ("got  size=%d exp=%ld\n", SIZ(got), EXP(got));
  mpn_trace ("     limbs=", PTR(got), ABSIZ(got));

  printf ("want size=%d exp=%ld\n", SIZ(want), EXP(want));
  mpn_trace ("     limbs=", PTR(want), ABSIZ(want));
}

void
check_one (mpf_srcptr src, mpf_srcptr trunc, mpf_srcptr ceil, mpf_srcptr floor)
{
  mpf_t  got;

  mpf_init2 (got, mpf_get_prec (trunc));
  ASSERT_ALWAYS (PREC(got) == PREC(trunc));
  ASSERT_ALWAYS (PREC(got) == PREC(ceil));
  ASSERT_ALWAYS (PREC(got) == PREC(floor));

#define CHECK_SEP(name, fun, want)              \
  mpf_set_ui (got, 54321L); /* initial junk */  \
  fun (got, src);                               \
  MPF_CHECK_FORMAT (got);                       \
  if (mpf_cmp (got, want) != 0)                 \
    {                                           \
        printf ("%s wrong\n", name);            \
        check_print (src, got, want);           \
        abort ();                               \
    }

  CHECK_SEP ("mpf_trunc", mpf_trunc, trunc);
  CHECK_SEP ("mpf_ceil",  mpf_ceil,  ceil);
  CHECK_SEP ("mpf_floor", mpf_floor, floor);

#define CHECK_INPLACE(name, fun, want)  \
  mpf_set (got, src);                   \
  fun (got, got);                       \
  MPF_CHECK_FORMAT (got);               \
  if (mpf_cmp (got, want) != 0)         \
    {                                   \
        printf ("%s wrong\n", name);    \
        check_print (src, got, want);   \
        abort ();                       \
    }

  CHECK_INPLACE ("mpf_trunc", mpf_trunc, trunc);

  /* Can't do these unconditionally in case truncation by mpf_set strips
     some low non-zero limbs which would have rounded the result.  */
  if (ABSIZ(src) <= PREC(trunc)+1)
    {
      CHECK_INPLACE ("mpf_ceil",  mpf_ceil,  ceil);
      CHECK_INPLACE ("mpf_floor", mpf_floor, floor);
    }

  mpf_clear (got);
}

void
check_all (mpf_ptr src, mpf_ptr trunc, mpf_ptr ceil, mpf_ptr floor)
{
  /* some of these values are generated with direct field assignments */
  MPF_CHECK_FORMAT (src);
  MPF_CHECK_FORMAT (trunc);
  MPF_CHECK_FORMAT (ceil);
  MPF_CHECK_FORMAT (floor);

  check_one (src, trunc, ceil, floor);

  mpf_neg (src,   src);
  mpf_neg (trunc, trunc);
  mpf_neg (ceil,  ceil);
  mpf_neg (floor, floor);
  check_one (src, trunc, floor, ceil);
}

void
check_various (void)
{
  mpf_t  src, trunc, ceil, floor;
  int    n, i;

  mpf_init2 (src, 512L);
  mpf_init2 (trunc, 256L);
  mpf_init2 (ceil,  256L);
  mpf_init2 (floor, 256L);

  /* 0 */
  mpf_set_ui (src, 0L);
  mpf_set_ui (trunc, 0L);
  mpf_set_ui (ceil, 0L);
  mpf_set_ui (floor, 0L);
  check_all (src, trunc, ceil, floor);

  /* 1 */
  mpf_set_ui (src, 1L);
  mpf_set_ui (trunc, 1L);
  mpf_set_ui (ceil, 1L);
  mpf_set_ui (floor, 1L);
  check_all (src, trunc, ceil, floor);

  /* 2^1024 */
  mpf_set_ui (src, 1L);
  mpf_mul_2exp (src,   src,   1024L);
  mpf_set (trunc, src);
  mpf_set (ceil,  src);
  mpf_set (floor, src);
  check_all (src, trunc, ceil, floor);
  
  /* 1/2^1024, fraction only */
  mpf_set_ui (src, 1L);
  mpf_div_2exp (src,  src, 1024L);
  mpf_set_si (trunc, 0L);
  mpf_set_si (ceil, 1L);
  mpf_set_si (floor, 0L);
  check_all (src, trunc, ceil, floor);

  /* 1/2 */
  mpf_set_ui (src, 1L);
  mpf_div_2exp (src,  src, 1L);
  mpf_set_si (trunc, 0L);
  mpf_set_si (ceil, 1L);
  mpf_set_si (floor, 0L);
  check_all (src, trunc, ceil, floor);
  
  /* 123+1/2^64 */
  mpf_set_ui (src, 1L);
  mpf_div_2exp (src,  src, 64L);
  mpf_add_ui (src,  src, 123L);
  mpf_set_si (trunc, 123L);
  mpf_set_si (ceil, 124L);
  mpf_set_si (floor, 123L);
  check_all (src, trunc, ceil, floor);

  /* integer of full prec+1 limbs, unchanged */
  n = PREC(trunc)+1;
  ASSERT_ALWAYS (n <= PREC(src)+1);
  EXP(src) = n;
  SIZ(src) = n;
  for (i = 0; i < SIZ(src); i++)
    PTR(src)[i] = i+100;
  mpf_set (trunc, src);
  mpf_set (ceil, src);
  mpf_set (floor, src);
  check_all (src, trunc, ceil, floor);

  /* full prec+1 limbs, 1 trimmed for integer */
  n = PREC(trunc)+1;
  ASSERT_ALWAYS (n <= PREC(src)+1);
  EXP(src) = n-1;
  SIZ(src) = n;
  for (i = 0; i < SIZ(src); i++)
    PTR(src)[i] = i+200;
  EXP(trunc) = n-1;
  SIZ(trunc) = n-1;
  for (i = 0; i < SIZ(trunc); i++)
    PTR(trunc)[i] = i+201;
  mpf_set (floor, trunc);
  mpf_add_ui (ceil, trunc, 1L);
  check_all (src, trunc, ceil, floor);

  /* prec+3 limbs, 2 trimmed for size */
  n = PREC(trunc)+3;
  ASSERT_ALWAYS (n <= PREC(src)+1);
  EXP(src) = n;
  SIZ(src) = n;
  for (i = 0; i < SIZ(src); i++)
    PTR(src)[i] = i+300;
  EXP(trunc) = n;
  SIZ(trunc) = n-2;
  for (i = 0; i < SIZ(trunc); i++)
    PTR(trunc)[i] = i+302;
  mpf_set (floor, trunc);
  mpf_set (ceil, trunc);
  PTR(ceil)[0]++;
  check_all (src, trunc, ceil, floor);

  /* prec+4 limbs, 2 trimmed for size, 1 trimmed for integer */
  n = PREC(trunc)+4;
  ASSERT_ALWAYS (n <= PREC(src)+1);
  EXP(src) = n-1;
  SIZ(src) = n;
  for (i = 0; i < SIZ(src); i++)
    PTR(src)[i] = i+400;
  EXP(trunc) = n-1;
  SIZ(trunc) = n-3;
  for (i = 0; i < SIZ(trunc); i++)
    PTR(trunc)[i] = i+403;
  mpf_set (floor, trunc);
  mpf_set (ceil, trunc);
  PTR(ceil)[0]++;
  check_all (src, trunc, ceil, floor);

  /* F.F, carry out of ceil */
  EXP(src) = 1;
  SIZ(src) = 2;
  PTR(src)[0] = GMP_NUMB_MAX;
  PTR(src)[1] = GMP_NUMB_MAX;
  EXP(trunc) = 1;
  SIZ(trunc) = 1;
  PTR(trunc)[0] = GMP_NUMB_MAX;
  mpf_set (floor, trunc);
  EXP(ceil) = 2;
  SIZ(ceil) = 1;
  PTR(ceil)[0] = 1;
  check_all (src, trunc, ceil, floor);

  /* FF.F, carry out of ceil */
  EXP(src) = 2;
  SIZ(src) = 3;
  PTR(src)[0] = GMP_NUMB_MAX;
  PTR(src)[1] = GMP_NUMB_MAX;
  PTR(src)[2] = GMP_NUMB_MAX;
  EXP(trunc) = 2;
  SIZ(trunc) = 2;
  PTR(trunc)[0] = GMP_NUMB_MAX;
  PTR(trunc)[1] = GMP_NUMB_MAX;
  mpf_set (floor, trunc);
  EXP(ceil) = 3;
  SIZ(ceil) = 1;
  PTR(ceil)[0] = 1;
  check_all (src, trunc, ceil, floor);

  mpf_clear (src);
  mpf_clear (trunc);
  mpf_clear (ceil);
  mpf_clear (floor);
}

int
main (void)
{
  tests_start ();

  check_various ();

  tests_end ();
  exit (0);
}