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/*
Copyright 2012, 2016 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 <assert.h>
#include <limits.h>
#include <stdlib.h>
#include <stdio.h>
#include "testutils.h"
#define GMP_LIMB_BITS (sizeof(mp_limb_t) * CHAR_BIT)
#define COUNT 10000
static void
test_2by1(const mpz_t u)
{
mpz_t m, p, t;
mpz_init (m);
mpz_init (p);
mpz_init (t);
assert (mpz_size (u) == 1);
mpz_set_ui (m, mpn_invert_limb (u->_mp_d[0]));
mpz_setbit (m, GMP_LIMB_BITS);
mpz_mul (p, m, u);
mpz_set_ui (t, 0);
mpz_setbit (t, 2* GMP_LIMB_BITS);
mpz_sub (t, t, p);
/* Should have 0 < B^2 - m u <= u */
if (mpz_sgn (t) <= 0 || mpz_cmp (t, u) > 0)
{
fprintf (stderr, "mpn_invert_limb failed:\n");
dump ("u", u);
dump ("m", m);
dump ("p", p);
dump ("t", t);
abort ();
}
mpz_clear (m);
mpz_clear (p);
mpz_clear (t);
}
static void
test_3by2(const mpz_t u)
{
mpz_t m, p, t;
mpz_init (m);
mpz_init (p);
mpz_init (t);
assert (mpz_size (u) == 2);
mpz_set_ui (m, mpn_invert_3by2 (u->_mp_d[1], u[0]._mp_d[0]));
mpz_setbit (m, GMP_LIMB_BITS);
mpz_mul (p, m, u);
mpz_set_ui (t, 0);
mpz_setbit (t, 3 * GMP_LIMB_BITS);
mpz_sub (t, t, p);
/* Should have 0 < B^3 - m u <= u */
if (mpz_sgn (t) <= 0 || mpz_cmp (t, u) > 0)
{
fprintf (stderr, "mpn_invert_3by2 failed:\n");
dump ("u", u);
dump ("m", m);
dump ("p", p);
dump ("t", t);
abort ();
}
mpz_clear (m);
mpz_clear (p);
mpz_clear (t);
}
void
testmain (int argc, char **argv)
{
unsigned i;
mpz_t u, m, p, t;
mpz_init (u);
mpz_init (m);
mpz_init (p);
mpz_init (t);
/* These values trigger 32-bit overflow of ql in mpn_invert_3by2. */
if (GMP_LIMB_BITS == 64)
{
mpz_set_str (u, "80007fff3ffe0000", 16);
test_2by1 (u);
mpz_set_str (u, "80007fff3ffe000000000000000003ff", 16);
test_3by2 (u);
}
for (i = 0; i < COUNT; i++)
{
mini_urandomb (u, GMP_LIMB_BITS);
mpz_setbit (u, GMP_LIMB_BITS -1);
test_2by1 (u);
}
for (i = 0; i < COUNT; i++)
{
mini_urandomb (u, 2*GMP_LIMB_BITS);
mpz_setbit (u, 2*GMP_LIMB_BITS -1);
test_3by2 (u);
}
mpz_clear (u);
}
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