1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
/* Test file for mpfr_urandom
Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
Contributed by the Arenaire and Cacao projects, INRIA.
This file is part of the GNU MPFR Library.
The GNU MPFR Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser 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 MPFR Library 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 Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see
http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
#include <stdio.h>
#include <stdlib.h>
#include "mpfr-test.h"
static void
test_urandom (long nbtests, mpfr_prec_t prec, mpfr_rnd_t rnd, long bit_index,
int verbose)
{
mpfr_t x;
int *tab, size_tab, k, sh, xn;
double d, av = 0, var = 0, chi2 = 0, th;
mpfr_exp_t emin;
mp_size_t limb_index = 0;
mp_limb_t limb_mask = 0;
long count = 0;
int i;
int inex = 1;
size_tab = (nbtests >= 1000 ? nbtests / 50 : 20);
tab = (int *) calloc (size_tab, sizeof(int));
if (tab == NULL)
{
fprintf (stderr, "trandom: can't allocate memory in test_urandom\n");
exit (1);
}
mpfr_init2 (x, prec);
xn = 1 + (prec - 1) / mp_bits_per_limb;
sh = xn * mp_bits_per_limb - prec;
if (bit_index >= 0 && bit_index < prec)
{
/* compute the limb index and limb mask to fetch the bit #bit_index */
limb_index = (prec - bit_index) / mp_bits_per_limb;
i = 1 + bit_index - (bit_index / mp_bits_per_limb) * mp_bits_per_limb;
limb_mask = MPFR_LIMB_ONE << (mp_bits_per_limb - i);
}
for (k = 0; k < nbtests; k++)
{
i = mpfr_urandom (x, RANDS, rnd);
inex = (i != 0) && inex;
/* check that lower bits are zero */
if (MPFR_MANT(x)[0] & MPFR_LIMB_MASK(sh) && !MPFR_IS_ZERO (x))
{
printf ("Error: mpfr_urandom() returns invalid numbers:\n");
mpfr_print_binary (x); puts ("");
exit (1);
}
/* check that the value is in [0,1] */
if (mpfr_cmp_ui (x, 0) < 0 || mpfr_cmp_ui (x, 1) > 0)
{
printf ("Error: mpfr_urandom() returns number outside [0, 1]:\n");
mpfr_print_binary (x); puts ("");
exit (1);
}
d = mpfr_get_d1 (x); av += d; var += d*d;
i = (int)(size_tab * d);
if (d == 1.0) i --;
tab[i]++;
if (limb_mask && (MPFR_MANT (x)[limb_index] & limb_mask))
count ++;
}
if (inex == 0)
{
/* one call in the loop pretended to return an exact number! */
printf ("Error: mpfr_urandom() returns a zero ternary value.\n");
exit (1);
}
/* coverage test */
emin = mpfr_get_emin ();
for (k = 0; k < 5; k++)
{
set_emin (k+1);
inex = mpfr_urandom (x, RANDS, rnd);
if (( (rnd == MPFR_RNDZ || rnd == MPFR_RNDD)
&& (!MPFR_IS_ZERO (x) || inex != -1))
|| ((rnd == MPFR_RNDU || rnd == MPFR_RNDA)
&& (mpfr_cmp_ui (x, 1 << k) != 0 || inex != +1))
|| (rnd == MPFR_RNDN
&& (k > 0 || mpfr_cmp_ui (x, 1 << k) != 0 || inex != +1)
&& (!MPFR_IS_ZERO (x) || inex != -1)))
{
printf ("Error: mpfr_urandom() do not handle correctly a restricted"
" exponent range.\nrounding mode: %s\nternary value: %d\n"
"random value: ", mpfr_print_rnd_mode (rnd), inex);
mpfr_print_binary (x); puts ("");
exit (1);
}
}
set_emin (emin);
mpfr_clear (x);
if (!verbose)
{
free(tab);
return;
}
av /= nbtests;
var = (var / nbtests) - av * av;
th = (double)nbtests / size_tab;
printf ("Average = %.5f\nVariance = %.5f\n", av, var);
printf ("Repartition for urandom with rounding mode %s. "
"Each integer should be close to %d.\n",
mpfr_print_rnd_mode (rnd), (int)th);
for (k = 0; k < size_tab; k++)
{
chi2 += (tab[k] - th) * (tab[k] - th) / th;
printf("%d ", tab[k]);
if (((k+1) & 7) == 0)
printf("\n");
}
printf("\nChi2 statistics value (with %d degrees of freedom) : %.5f\n",
size_tab - 1, chi2);
if (limb_mask)
printf ("Bit #%ld is set %ld/%ld = %.1f %% of time\n",
bit_index, count, nbtests, count * 100.0 / nbtests);
puts ("");
free(tab);
return;
}
int
main (int argc, char *argv[])
{
long nbtests;
mpfr_prec_t prec;
int verbose = 0;
int rnd;
long bit_index;
tests_start_mpfr ();
if (argc > 1)
verbose = 1;
nbtests = 10000;
if (argc > 1)
{
long a = atol(argv[1]);
if (a != 0)
nbtests = a;
}
if (argc <= 2)
prec = 1000;
else
prec = atol(argv[2]);
if (argc <= 3)
bit_index = -1;
else
{
bit_index = atol(argv[3]);
if (bit_index >= prec)
{
printf ("Warning. Cannot compute the bit frequency: the given bit "
"index (= %ld) is not less than the precision (= %ld).\n",
bit_index, prec);
bit_index = -1;
}
}
RND_LOOP(rnd)
{
test_urandom (nbtests, prec, (mpfr_rnd_t) rnd, bit_index, verbose);
if (argc == 1) /* check also small precision */
{
test_urandom (nbtests, 2, (mpfr_rnd_t) rnd, -1, 0);
}
}
tests_end_mpfr ();
return 0;
}
|
