xref: /netbsd-src/external/lgpl3/gmp/dist/tests/mpn/t-invert.c (revision 567219e1d7461bff1b180e494a9674a287b057a7)
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.
8 
9 The GNU MP Library is free software; you can redistribute it and/or modify
10 it under the terms of the GNU Lesser General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or (at your
12 option) any later version.
13 
14 The GNU MP Library is distributed in the hope that it will be useful, but
15 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
16 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
17 License for more details.
18 
19 You should have received a copy of the GNU Lesser General Public License
20 along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
21 
22 
23 #include "gmp.h"
24 #include "gmp-impl.h"
25 #include "tests.h"
26 
27 #include <stdlib.h>
28 #include <stdio.h>
29 
30 /* Sizes are up to 2^SIZE_LOG limbs */
31 #ifndef SIZE_LOG
32 #define SIZE_LOG 12
33 #endif
34 
35 #ifndef COUNT
36 #define COUNT 1000
37 #endif
38 
39 #define MAX_N (1L << SIZE_LOG)
40 #define MIN_N 1
41 
42 
43 static int
44 invert_valid (mp_srcptr ip, mp_srcptr dp, mp_size_t n)
45 {
46   mp_ptr tp;
47   int cy;
48   TMP_DECL;
49 
50   TMP_MARK;
51   tp = TMP_ALLOC_LIMBS (2*n);
52 
53   refmpn_mul (tp, ip, n, dp, n);
54   cy  = refmpn_add_n (tp + n, tp + n, dp, n); /* This must not give a carry. */
55   cy -= refmpn_add (tp, tp, 2*n, dp, n); /* This must give a carry. */
56   TMP_FREE;
57 
58   return (cy == -1);
59 }
60 
61 /*
62   Chech the result of the mpn_invert function in the library.
63 */
64 
65 int
66 main (int argc, char **argv)
67 {
68   mp_ptr ip, dp, scratch;
69   int count = COUNT;
70   int test;
71   gmp_randstate_ptr rands;
72   TMP_DECL;
73   TMP_MARK;
74 
75   if (argc > 1)
76     {
77       char *end;
78       count = strtol (argv[1], &end, 0);
79       if (*end || count <= 0)
80 	{
81 	  fprintf (stderr, "Invalid test count: %s.\n", argv[1]);
82 	  return 1;
83 	}
84     }
85 
86   tests_start ();
87   rands = RANDS;
88 
89   dp = TMP_ALLOC_LIMBS (MAX_N);
90   ip = 1+TMP_ALLOC_LIMBS (MAX_N + 2);
91   scratch
92     = 1+TMP_ALLOC_LIMBS (mpn_invert_itch (MAX_N) + 2);
93 
94   for (test = 0; test < count; test++)
95     {
96       unsigned size_min;
97       unsigned size_range;
98       mp_size_t n;
99       mp_size_t itch;
100       mp_limb_t i_before, i_after, s_before, s_after;
101 
102       for (size_min = 1; (1L << size_min) < MIN_N; size_min++)
103 	;
104 
105       /* We generate an in the MIN_N <= n <= (1 << size_range). */
106       size_range = size_min
107 	+ gmp_urandomm_ui (rands, SIZE_LOG + 1 - size_min);
108 
109       n = MIN_N
110 	+ gmp_urandomm_ui (rands, (1L << size_range) + 1 - MIN_N);
111 
112       mpn_random2 (dp, n);
113 
114       mpn_random2 (ip-1, n + 2);
115       i_before = ip[-1];
116       i_after = ip[n];
117 
118       itch = mpn_invert_itch (n);
119       ASSERT_ALWAYS (itch <= mpn_invert_itch (MAX_N));
120       mpn_random2 (scratch-1, itch+2);
121       s_before = scratch[-1];
122       s_after = scratch[itch];
123 
124       dp[n-1] |= GMP_NUMB_HIGHBIT;
125       mpn_invert (ip, dp, n, scratch);
126       if (ip[-1] != i_before || ip[n] != i_after
127 	  || scratch[-1] != s_before || scratch[itch] != s_after
128 	  || ! invert_valid(ip, dp, n))
129 	{
130 	  printf ("ERROR in test %d, n = %d\n",
131 		  test, (int) n);
132 	  if (ip[-1] != i_before)
133 	    {
134 	      printf ("before ip:"); mpn_dump (ip -1, 1);
135 	      printf ("keep:   "); mpn_dump (&i_before, 1);
136 	    }
137 	  if (ip[n] != i_after)
138 	    {
139 	      printf ("after ip:"); mpn_dump (ip + n, 1);
140 	      printf ("keep:   "); mpn_dump (&i_after, 1);
141 	    }
142 	  if (scratch[-1] != s_before)
143 	    {
144 	      printf ("before scratch:"); mpn_dump (scratch-1, 1);
145 	      printf ("keep:   "); mpn_dump (&s_before, 1);
146 	    }
147 	  if (scratch[itch] != s_after)
148 	    {
149 	      printf ("after scratch:"); mpn_dump (scratch + itch, 1);
150 	      printf ("keep:   "); mpn_dump (&s_after, 1);
151 	    }
152 	  mpn_dump (dp, n);
153 	  mpn_dump (ip, n);
154 
155 	  abort();
156 	}
157     }
158   TMP_FREE;
159   tests_end ();
160   return 0;
161 }
162