1 /* Test mpn_gcdext_1.
2
3 Copyright 2019 Free Software Foundation, Inc.
4
5 This file is part of the GNU MP Library test suite.
6
7 The GNU MP Library test suite is free software; you can redistribute it
8 and/or modify it under the terms of the GNU General Public License as
9 published by the Free Software Foundation; either version 3 of the License,
10 or (at your option) any later version.
11
12 The GNU MP Library test suite is distributed in the hope that it will be
13 useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
15 Public License for more details.
16
17 You should have received a copy of the GNU General Public License along with
18 the GNU MP Library test suite. If not, see https://www.gnu.org/licenses/. */
19
20 #include <stdio.h>
21 #include <stdlib.h>
22
23 #include "gmp-impl.h"
24 #include "tests.h"
25
26 #ifndef COUNT
27 #define COUNT 250000
28 #endif
29
30 static void
set_signed_limb(mpz_t r,mp_limb_signed_t x)31 set_signed_limb (mpz_t r, mp_limb_signed_t x)
32 {
33 mpz_t t;
34 mp_limb_t abs_x = ABS_CAST(mp_limb_t, x);
35 mpz_set (r, mpz_roinit_n (t, &abs_x, 1));
36 if (x < 0)
37 mpz_neg (r, r);
38 }
39
40 static void
one_test(mp_limb_t a,mp_limb_t b)41 one_test (mp_limb_t a, mp_limb_t b)
42 {
43 mp_limb_signed_t s, t;
44 mp_limb_t g;
45
46 g = mpn_gcdext_1 (&s, &t, a, b);
47
48 if (g > 0)
49 {
50 mpz_t d, sz, tz, tmp;
51
52 mpz_init (d);
53 mpz_init (sz);
54 mpz_init (tz);
55
56 set_signed_limb (sz, s);
57 set_signed_limb (tz, t);
58
59 mpz_mul (d, mpz_roinit_n (tmp, &a, 1), sz);
60 mpz_addmul (d, mpz_roinit_n (tmp, &b, 1), tz);
61
62 if (mpz_cmp (d, mpz_roinit_n (tmp, &g, 1)) == 0
63 && a % g == 0 && b % g == 0)
64 {
65 mp_limb_t a_div_g = a / g;
66 mp_limb_t b_div_g = b / g;
67 mp_limb_t abs_s = ABS_CAST(mp_limb_t, s);
68 mp_limb_t abs_t = ABS_CAST(mp_limb_t, t);
69 mpz_mul_ui (sz, sz, 2);
70 mpz_mul_ui (tz, tz, 2);
71 if ((abs_s == 1 || mpz_cmpabs (sz, mpz_roinit_n (tmp, &b_div_g, 1)) < 0)
72 && (abs_t == 1 || mpz_cmpabs (tz, mpz_roinit_n (tmp, &a_div_g, 1)) < 0))
73 {
74 mpz_clear (d);
75 mpz_clear (sz);
76 mpz_clear (tz);
77
78 return;
79 }
80 }
81 }
82 gmp_fprintf (stderr,
83 "gcdext_1 (0x%Mx, 0x%Mx) failed, got: g = 0x%Mx, s = %s0x%Mx, t = %s0x%Mx\n",
84 a, b, g,
85 s < 0 ? "-" : "", ABS_CAST(mp_limb_t, s),
86 t < 0 ? "-" : "", ABS_CAST(mp_limb_t, t));
87 abort();
88 }
89
90 int
main(int argc,char ** argv)91 main (int argc, char **argv)
92 {
93 mpz_t a, b;
94 int count = COUNT;
95 int test;
96 gmp_randstate_ptr rands;
97
98 TESTS_REPS (count, argv, argc);
99
100 tests_start ();
101 rands = RANDS;
102
103 mpz_init (a);
104 mpz_init (b);
105 for (test = 0; test < count; test++)
106 {
107 mp_limb_t al, bl;
108 mp_bitcnt_t asize = 1 + gmp_urandomm_ui(rands, GMP_NUMB_BITS);
109 mp_bitcnt_t bsize = 1 + gmp_urandomm_ui(rands, GMP_NUMB_BITS);
110 if (test & 1)
111 {
112 mpz_urandomb (a, rands, asize);
113 mpz_urandomb (b, rands, bsize);
114 }
115 else
116 {
117 mpz_rrandomb (a, rands, asize);
118 mpz_rrandomb (b, rands, bsize);
119 }
120
121 al = mpz_getlimbn (a, 0);
122 bl = mpz_getlimbn (b, 0);
123 al += (al == 0);
124 bl += (bl == 0);
125
126 one_test (al, bl);
127 }
128
129 mpz_clear (a);
130 mpz_clear (b);
131
132 tests_end ();
133 return 0;
134 }
135