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/* Test mpn_hgcd.
Copyright 1991, 1993, 1994, 1996, 1997, 2000-2004 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-impl.h"
#include "tests.h"
static mp_size_t one_test (mpz_t, mpz_t, int);
static void debug_mp (mpz_t, int);
#define MIN_OPERAND_SIZE 2
/* Fixed values, for regression testing of mpn_hgcd. */
struct value { int res; const char *a; const char *b; };
static const struct value hgcd_values[] = {
#if GMP_NUMB_BITS == 32
{ 5,
"0x1bddff867272a9296ac493c251d7f46f09a5591fe",
"0xb55930a2a68a916450a7de006031068c5ddb0e5c" },
{ 4,
"0x2f0ece5b1ee9c15e132a01d55768dc13",
"0x1c6f4fd9873cdb24466e6d03e1cc66e7" },
{ 3, "0x7FFFFC003FFFFFFFFFC5", "0x3FFFFE001FFFFFFFFFE3"},
#endif
{ -1, NULL, NULL }
};
struct hgcd_ref
{
mpz_t m[2][2];
};
static void hgcd_ref_init (struct hgcd_ref *);
static void hgcd_ref_clear (struct hgcd_ref *);
static int hgcd_ref (struct hgcd_ref *, mpz_t, mpz_t);
static int hgcd_ref_equal (const struct hgcd_matrix *, const struct hgcd_ref *);
int
main (int argc, char **argv)
{
mpz_t op1, op2, temp1, temp2;
int i, j, chain_len;
gmp_randstate_ptr rands;
mpz_t bs;
unsigned long size_range;
tests_start ();
rands = RANDS;
mpz_init (bs);
mpz_init (op1);
mpz_init (op2);
mpz_init (temp1);
mpz_init (temp2);
for (i = 0; hgcd_values[i].res >= 0; i++)
{
mp_size_t res;
mpz_set_str (op1, hgcd_values[i].a, 0);
mpz_set_str (op2, hgcd_values[i].b, 0);
res = one_test (op1, op2, -1-i);
if (res != hgcd_values[i].res)
{
fprintf (stderr, "ERROR in test %d\n", -1-i);
fprintf (stderr, "Bad return code from hgcd\n");
fprintf (stderr, "op1="); debug_mp (op1, -16);
fprintf (stderr, "op2="); debug_mp (op2, -16);
fprintf (stderr, "expected: %d\n", hgcd_values[i].res);
fprintf (stderr, "hgcd: %d\n", (int) res);
abort ();
}
}
for (i = 0; i < 15; i++)
{
/* Generate plain operands with unknown gcd. These types of operands
have proven to trigger certain bugs in development versions of the
gcd code. */
mpz_urandomb (bs, rands, 32);
size_range = mpz_get_ui (bs) % 13 + 2;
mpz_urandomb (bs, rands, size_range);
mpz_rrandomb (op1, rands, mpz_get_ui (bs) + MIN_OPERAND_SIZE);
mpz_urandomb (bs, rands, size_range);
mpz_rrandomb (op2, rands, mpz_get_ui (bs) + MIN_OPERAND_SIZE);
if (mpz_cmp (op1, op2) < 0)
mpz_swap (op1, op2);
if (mpz_size (op1) > 0)
one_test (op1, op2, i);
/* Generate a division chain backwards, allowing otherwise
unlikely huge quotients. */
mpz_set_ui (op1, 0);
mpz_urandomb (bs, rands, 32);
mpz_urandomb (bs, rands, mpz_get_ui (bs) % 16 + 1);
mpz_rrandomb (op2, rands, mpz_get_ui (bs));
mpz_add_ui (op2, op2, 1);
#if 0
chain_len = 1000000;
#else
mpz_urandomb (bs, rands, 32);
chain_len = mpz_get_ui (bs) % (GMP_NUMB_BITS * GCD_DC_THRESHOLD / 256);
#endif
for (j = 0; j < chain_len; j++)
{
mpz_urandomb (bs, rands, 32);
mpz_urandomb (bs, rands, mpz_get_ui (bs) % 12 + 1);
mpz_rrandomb (temp2, rands, mpz_get_ui (bs) + 1);
mpz_add_ui (temp2, temp2, 1);
mpz_mul (temp1, op2, temp2);
mpz_add (op1, op1, temp1);
/* Don't generate overly huge operands. */
if (SIZ (op1) > 3 * GCD_DC_THRESHOLD)
break;
mpz_urandomb (bs, rands, 32);
mpz_urandomb (bs, rands, mpz_get_ui (bs) % 12 + 1);
mpz_rrandomb (temp2, rands, mpz_get_ui (bs) + 1);
mpz_add_ui (temp2, temp2, 1);
mpz_mul (temp1, op1, temp2);
mpz_add (op2, op2, temp1);
/* Don't generate overly huge operands. */
if (SIZ (op2) > 3 * GCD_DC_THRESHOLD)
break;
}
if (mpz_cmp (op1, op2) < 0)
mpz_swap (op1, op2);
if (mpz_size (op1) > 0)
one_test (op1, op2, i);
}
mpz_clear (bs);
mpz_clear (op1);
mpz_clear (op2);
mpz_clear (temp1);
mpz_clear (temp2);
tests_end ();
exit (0);
}
static void
debug_mp (mpz_t x, int base)
{
mpz_out_str (stderr, base, x); fputc ('\n', stderr);
}
static int
mpz_mpn_equal (const mpz_t a, mp_srcptr bp, mp_size_t bsize);
static mp_size_t
one_test (mpz_t a, mpz_t b, int i)
{
struct hgcd_matrix hgcd;
struct hgcd_ref ref;
mpz_t ref_r0;
mpz_t ref_r1;
mpz_t hgcd_r0;
mpz_t hgcd_r1;
mp_size_t res[2];
mp_size_t asize;
mp_size_t bsize;
mp_size_t hgcd_init_scratch;
mp_size_t hgcd_scratch;
mp_ptr hgcd_init_tp;
mp_ptr hgcd_tp;
asize = a->_mp_size;
bsize = b->_mp_size;
ASSERT (asize >= bsize);
hgcd_init_scratch = MPN_HGCD_MATRIX_INIT_ITCH (asize);
hgcd_init_tp = refmpn_malloc_limbs (hgcd_init_scratch);
mpn_hgcd_matrix_init (&hgcd, asize, hgcd_init_tp);
hgcd_scratch = mpn_hgcd_itch (asize);
hgcd_tp = refmpn_malloc_limbs (hgcd_scratch);
#if 0
fprintf (stderr,
"one_test: i = %d asize = %d, bsize = %d\n",
i, a->_mp_size, b->_mp_size);
gmp_fprintf (stderr,
"one_test: i = %d\n"
" a = %Zx\n"
" b = %Zx\n",
i, a, b);
#endif
hgcd_ref_init (&ref);
mpz_init_set (ref_r0, a);
mpz_init_set (ref_r1, b);
res[0] = hgcd_ref (&ref, ref_r0, ref_r1);
mpz_init_set (hgcd_r0, a);
mpz_init_set (hgcd_r1, b);
if (bsize < asize)
{
_mpz_realloc (hgcd_r1, asize);
MPN_ZERO (hgcd_r1->_mp_d + bsize, asize - bsize);
}
res[1] = mpn_hgcd (hgcd_r0->_mp_d,
hgcd_r1->_mp_d,
asize,
&hgcd, hgcd_tp);
if (res[0] != res[1])
{
fprintf (stderr, "ERROR in test %d\n", i);
fprintf (stderr, "Different return value from hgcd and hgcd_ref\n");
fprintf (stderr, "op1="); debug_mp (a, -16);
fprintf (stderr, "op2="); debug_mp (b, -16);
fprintf (stderr, "hgcd_ref: %ld\n", (long) res[0]);
fprintf (stderr, "mpn_hgcd: %ld\n", (long) res[1]);
abort ();
}
if (res[0] > 0)
{
if (!hgcd_ref_equal (&hgcd, &ref)
|| !mpz_mpn_equal (ref_r0, hgcd_r0->_mp_d, res[1])
|| !mpz_mpn_equal (ref_r1, hgcd_r1->_mp_d, res[1]))
{
fprintf (stderr, "ERROR in test %d\n", i);
fprintf (stderr, "mpn_hgcd and hgcd_ref returned different values\n");
fprintf (stderr, "op1="); debug_mp (a, -16);
fprintf (stderr, "op2="); debug_mp (b, -16);
abort ();
}
}
refmpn_free_limbs (hgcd_init_tp);
refmpn_free_limbs (hgcd_tp);
hgcd_ref_clear (&ref);
mpz_clear (ref_r0);
mpz_clear (ref_r1);
mpz_clear (hgcd_r0);
mpz_clear (hgcd_r1);
return res[0];
}
static void
hgcd_ref_init (struct hgcd_ref *hgcd)
{
unsigned i;
for (i = 0; i<2; i++)
{
unsigned j;
for (j = 0; j<2; j++)
mpz_init (hgcd->m[i][j]);
}
}
static void
hgcd_ref_clear (struct hgcd_ref *hgcd)
{
unsigned i;
for (i = 0; i<2; i++)
{
unsigned j;
for (j = 0; j<2; j++)
mpz_clear (hgcd->m[i][j]);
}
}
static int
sdiv_qr (mpz_t q, mpz_t r, mp_size_t s, const mpz_t a, const mpz_t b)
{
mpz_fdiv_qr (q, r, a, b);
if (mpz_size (r) <= s)
{
mpz_add (r, r, b);
mpz_sub_ui (q, q, 1);
}
return (mpz_sgn (q) > 0);
}
static int
hgcd_ref (struct hgcd_ref *hgcd, mpz_t a, mpz_t b)
{
mp_size_t n = MAX (mpz_size (a), mpz_size (b));
mp_size_t s = n/2 + 1;
mp_size_t asize;
mp_size_t bsize;
mpz_t q;
int res;
if (mpz_size (a) <= s || mpz_size (b) <= s)
return 0;
res = mpz_cmp (a, b);
if (res < 0)
{
mpz_sub (b, b, a);
if (mpz_size (b) <= s)
return 0;
mpz_set_ui (hgcd->m[0][0], 1); mpz_set_ui (hgcd->m[0][1], 0);
mpz_set_ui (hgcd->m[1][0], 1); mpz_set_ui (hgcd->m[1][1], 1);
}
else if (res > 0)
{
mpz_sub (a, a, b);
if (mpz_size (a) <= s)
return 0;
mpz_set_ui (hgcd->m[0][0], 1); mpz_set_ui (hgcd->m[0][1], 1);
mpz_set_ui (hgcd->m[1][0], 0); mpz_set_ui (hgcd->m[1][1], 1);
}
else
return 0;
mpz_init (q);
for (;;)
{
ASSERT (mpz_size (a) > s);
ASSERT (mpz_size (b) > s);
if (mpz_cmp (a, b) > 0)
{
if (!sdiv_qr (q, a, s, a, b))
break;
mpz_addmul (hgcd->m[0][1], q, hgcd->m[0][0]);
mpz_addmul (hgcd->m[1][1], q, hgcd->m[1][0]);
}
else
{
if (!sdiv_qr (q, b, s, b, a))
break;
mpz_addmul (hgcd->m[0][0], q, hgcd->m[0][1]);
mpz_addmul (hgcd->m[1][0], q, hgcd->m[1][1]);
}
}
mpz_clear (q);
asize = mpz_size (a);
bsize = mpz_size (b);
return MAX (asize, bsize);
}
static int
mpz_mpn_equal (const mpz_t a, mp_srcptr bp, mp_size_t bsize)
{
mp_srcptr ap = a->_mp_d;
mp_size_t asize = a->_mp_size;
MPN_NORMALIZE (bp, bsize);
return asize == bsize && mpn_cmp (ap, bp, asize) == 0;
}
static int
hgcd_ref_equal (const struct hgcd_matrix *hgcd, const struct hgcd_ref *ref)
{
unsigned i;
for (i = 0; i<2; i++)
{
unsigned j;
for (j = 0; j<2; j++)
if (!mpz_mpn_equal (ref->m[i][j], hgcd->p[i][j], hgcd->n))
return 0;
}
return 1;
}
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