1 /* Test for mpn_invert function.
2
3 Contributed to the GNU project by Marco Bodrato.
4
5 Copyright 2009 Free Software Foundation, Inc.
6
7 This file is part of the GNU MP Library test suite.
8
9 The GNU MP Library test suite is free software; you can redistribute it
10 and/or modify it under the terms of the GNU General Public License as
11 published by the Free Software Foundation; either version 3 of the License,
12 or (at your option) any later version.
13
14 The GNU MP Library test suite is distributed in the hope that it will be
15 useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
17 Public License for more details.
18
19 You should have received a copy of the GNU General Public License along with
20 the GNU MP Library test suite. If not, see https://www.gnu.org/licenses/. */
21
22
23 #include <stdlib.h>
24 #include <stdio.h>
25
26 #include "gmp-impl.h"
27 #include "tests.h"
28
29 /* Sizes are up to 2^SIZE_LOG limbs */
30 #ifndef SIZE_LOG
31 #define SIZE_LOG 12
32 #endif
33
34 #ifndef COUNT
35 #define COUNT 1000
36 #endif
37
38 #define MAX_N (1L << SIZE_LOG)
39 #define MIN_N 1
40
41
42 static int
invert_valid(mp_srcptr ip,mp_srcptr dp,mp_size_t n)43 invert_valid (mp_srcptr ip, mp_srcptr dp, mp_size_t n)
44 {
45 mp_ptr tp;
46 int cy;
47 TMP_DECL;
48
49 TMP_MARK;
50 tp = TMP_ALLOC_LIMBS (2*n);
51
52 refmpn_mul (tp, ip, n, dp, n);
53 cy = refmpn_add_n (tp + n, tp + n, dp, n); /* This must not give a carry. */
54 cy -= refmpn_add (tp, tp, 2*n, dp, n); /* This must give a carry. */
55 TMP_FREE;
56
57 return (cy == -1);
58 }
59
60 /*
61 Check the result of the mpn_invert function in the library.
62 */
63
64 int
main(int argc,char ** argv)65 main (int argc, char **argv)
66 {
67 mp_ptr ip, dp, scratch;
68 int count = COUNT;
69 int test;
70 gmp_randstate_ptr rands;
71 TMP_DECL;
72 TMP_MARK;
73
74 TESTS_REPS (count, argv, argc);
75
76 tests_start ();
77 rands = RANDS;
78
79 dp = TMP_ALLOC_LIMBS (MAX_N);
80 ip = 1+TMP_ALLOC_LIMBS (MAX_N + 2);
81 scratch
82 = 1+TMP_ALLOC_LIMBS (mpn_invert_itch (MAX_N) + 2);
83
84 for (test = 0; test < count; test++)
85 {
86 unsigned size_min;
87 unsigned size_range;
88 mp_size_t n;
89 mp_size_t itch;
90 mp_limb_t i_before, i_after, s_before, s_after;
91
92 for (size_min = 1; (1L << size_min) < MIN_N; size_min++)
93 ;
94
95 /* We generate an in the MIN_N <= n <= (1 << size_range). */
96 size_range = size_min
97 + gmp_urandomm_ui (rands, SIZE_LOG + 1 - size_min);
98
99 n = MIN_N
100 + gmp_urandomm_ui (rands, (1L << size_range) + 1 - MIN_N);
101
102 mpn_random2 (dp, n);
103
104 mpn_random2 (ip-1, n + 2);
105 i_before = ip[-1];
106 i_after = ip[n];
107
108 itch = mpn_invert_itch (n);
109 ASSERT_ALWAYS (itch <= mpn_invert_itch (MAX_N));
110 mpn_random2 (scratch-1, itch+2);
111 s_before = scratch[-1];
112 s_after = scratch[itch];
113
114 dp[n-1] |= GMP_NUMB_HIGHBIT;
115 mpn_invert (ip, dp, n, scratch);
116 if (ip[-1] != i_before || ip[n] != i_after
117 || scratch[-1] != s_before || scratch[itch] != s_after
118 || ! invert_valid(ip, dp, n))
119 {
120 printf ("ERROR in test %d, n = %d\n",
121 test, (int) n);
122 if (ip[-1] != i_before)
123 {
124 printf ("before ip:"); mpn_dump (ip -1, 1);
125 printf ("keep: "); mpn_dump (&i_before, 1);
126 }
127 if (ip[n] != i_after)
128 {
129 printf ("after ip:"); mpn_dump (ip + n, 1);
130 printf ("keep: "); mpn_dump (&i_after, 1);
131 }
132 if (scratch[-1] != s_before)
133 {
134 printf ("before scratch:"); mpn_dump (scratch-1, 1);
135 printf ("keep: "); mpn_dump (&s_before, 1);
136 }
137 if (scratch[itch] != s_after)
138 {
139 printf ("after scratch:"); mpn_dump (scratch + itch, 1);
140 printf ("keep: "); mpn_dump (&s_after, 1);
141 }
142 mpn_dump (dp, n);
143 mpn_dump (ip, n);
144
145 abort();
146 }
147 }
148 TMP_FREE;
149 tests_end ();
150 return 0;
151 }
152