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688903eb | 1 | /* Copyright (C) 1997-2018 Free Software Foundation, Inc. |
9a0a462c UD |
2 | This file is part of the GNU C Library. |
3 | Contributed by Geoffrey Keating <Geoff.Keating@anu.edu.au>, 1997. | |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
41bdb6e2 AJ |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
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9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
41bdb6e2 | 13 | Lesser General Public License for more details. |
9a0a462c | 14 | |
41bdb6e2 | 15 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
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18 | |
19 | #include <stdio.h> | |
20 | #include <math.h> | |
48896b9d | 21 | #include <gmp.h> |
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22 | #include <string.h> |
23 | #include <limits.h> | |
24 | #include <assert.h> | |
25 | ||
26 | #define PRINT_ERRORS 0 | |
27 | ||
28 | #define TOL 80 | |
29 | #define N2 17 | |
30 | #define FRAC (32*4) | |
31 | ||
32 | #define mpbpl (CHAR_BIT * sizeof (mp_limb_t)) | |
33 | #define SZ (FRAC / mpbpl + 1) | |
34 | typedef mp_limb_t mp1[SZ], mp2[SZ * 2]; | |
35 | ||
36 | /* This string has 101 hex digits. */ | |
37 | static const char exp1[102] = "2" /* point */ | |
38 | "b7e151628aed2a6abf7158809cf4f3c762e7160f38b4da56a7" | |
39 | "84d9045190cfef324e7738926cfbe5f4bf8d8d8c31d763da07"; | |
40 | static const char hexdig[] = "0123456789abcdef"; | |
41 | ||
767b6275 | 42 | static void |
9a0a462c UD |
43 | print_mpn_hex (const mp_limb_t *x, unsigned size) |
44 | { | |
45 | char value[size + 1]; | |
46 | unsigned i; | |
47 | const unsigned final = (size * 4 > SZ * mpbpl) ? SZ * mpbpl / 4 : size; | |
48 | ||
49 | memset (value, '0', size); | |
50 | ||
51 | for (i = 0; i < final ; i++) | |
52 | value[size - 1 - i] = hexdig[x[i * 4 / mpbpl] >> (i * 4) % mpbpl & 0xf]; | |
53 | ||
54 | value[size] = '\0'; | |
55 | fputs (value, stdout); | |
56 | } | |
57 | ||
767b6275 | 58 | static void |
9a0a462c UD |
59 | exp_mpn (mp1 ex, mp1 x) |
60 | { | |
61 | unsigned n; | |
62 | mp1 xp; | |
63 | mp2 tmp; | |
b4f518ec | 64 | mp_limb_t chk __attribute__ ((unused)); |
9a0a462c UD |
65 | mp1 tol; |
66 | ||
67 | memset (xp, 0, sizeof (mp1)); | |
68 | memset (ex, 0, sizeof (mp1)); | |
69bf5f75 | 69 | xp[FRAC / mpbpl] = (mp_limb_t)1 << FRAC % mpbpl; |
9a0a462c | 70 | memset (tol,0, sizeof (mp1)); |
69bf5f75 | 71 | tol[(FRAC - TOL) / mpbpl] = (mp_limb_t)1 << (FRAC - TOL) % mpbpl; |
9a0a462c UD |
72 | |
73 | n = 0; | |
74 | ||
75 | do | |
76 | { | |
77 | /* Calculate sum(x^n/n!) until the next term is sufficiently small. */ | |
78 | ||
79 | mpn_mul_n (tmp, xp, x, SZ); | |
80 | assert (tmp[SZ * 2 - 1] == 0); | |
81 | if (n > 0) | |
e4f22324 | 82 | mpn_divmod_1 (xp, tmp + FRAC / mpbpl, SZ, n); |
9a0a462c UD |
83 | chk = mpn_add_n (ex, ex, xp, SZ); |
84 | assert (chk == 0); | |
85 | n++; | |
86 | assert (n < 80); /* Catch too-high TOL. */ | |
87 | } | |
88 | while (n < 10 || mpn_cmp (xp, tol, SZ) >= 0); | |
89 | } | |
90 | ||
91 | static int | |
92 | mpn_bitsize(const mp_limb_t *SRC_PTR, mp_size_t SIZE) | |
93 | { | |
94 | int i, j; | |
95 | for (i = SIZE - 1; i > 0; i--) | |
96 | if (SRC_PTR[i] != 0) | |
97 | break; | |
b259e746 UD |
98 | for (j = mpbpl - 1; j >= 0; j--) |
99 | if ((SRC_PTR[i] & (mp_limb_t)1 << j) != 0) | |
9a0a462c UD |
100 | break; |
101 | ||
b259e746 | 102 | return i * mpbpl + j; |
9a0a462c UD |
103 | } |
104 | ||
29955b5d AS |
105 | static int |
106 | do_test (void) | |
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107 | { |
108 | mp1 ex, x, xt, e2, e3; | |
109 | int i; | |
110 | int errors = 0; | |
111 | int failures = 0; | |
112 | mp1 maxerror; | |
113 | int maxerror_s = 0; | |
114 | const double sf = pow (2, mpbpl); | |
115 | ||
116 | /* assert (mpbpl == mp_bits_per_limb); */ | |
117 | assert (FRAC / mpbpl * mpbpl == FRAC); | |
118 | ||
119 | memset (maxerror, 0, sizeof (mp1)); | |
120 | memset (xt, 0, sizeof (mp1)); | |
69bf5f75 | 121 | xt[(FRAC - N2) / mpbpl] = (mp_limb_t)1 << (FRAC - N2) % mpbpl; |
9a0a462c UD |
122 | |
123 | for (i = 0; i < 1 << N2; i++) | |
124 | { | |
125 | int e2s, e3s, j; | |
126 | double de2; | |
127 | ||
128 | mpn_mul_1 (x,xt,SZ,i); | |
129 | exp_mpn (ex, x); | |
130 | de2 = exp (i / (double) (1 << N2)); | |
131 | for (j = SZ-1; j >= 0; j--) | |
132 | { | |
133 | e2[j] = (mp_limb_t) de2; | |
134 | de2 = (de2 - e2[j]) * sf; | |
135 | } | |
136 | if (mpn_cmp (ex,e2,SZ) >= 0) | |
137 | mpn_sub_n (e3,ex,e2,SZ); | |
138 | else | |
139 | mpn_sub_n (e3,e2,ex,SZ); | |
140 | ||
141 | e2s = mpn_bitsize (e2,SZ); | |
142 | e3s = mpn_bitsize (e3,SZ); | |
b259e746 | 143 | if (e3s >= 0 && e2s - e3s < 54) |
9a0a462c UD |
144 | { |
145 | #if PRINT_ERRORS | |
146 | printf ("%06x ", i * (0x100000 / (1 << N2))); | |
147 | print_mpn_hex (ex, (FRAC / 4) + 1); | |
148 | fputs ("\n ",stdout); | |
149 | print_mpn_hex (e2, (FRAC / 4) + 1); | |
150 | printf ("\n %c ", | |
151 | e2s - e3s < 54 ? e2s - e3s == 53 ? 'e' : 'F' : 'P'); | |
152 | print_mpn_hex (e3, (FRAC / 4) + 1); | |
153 | putchar ('\n'); | |
154 | #endif | |
155 | errors += (e2s - e3s == 53); | |
156 | failures += (e2s - e3s < 53); | |
157 | } | |
158 | if (e3s >= maxerror_s | |
159 | && mpn_cmp (e3, maxerror, SZ) > 0) | |
160 | { | |
161 | memcpy (maxerror, e3, sizeof (mp1)); | |
162 | maxerror_s = e3s; | |
163 | } | |
164 | } | |
165 | ||
166 | /* Check exp_mpn against precomputed value of exp(1). */ | |
167 | memset (x, '\0', sizeof (mp1)); | |
69bf5f75 | 168 | x[FRAC / mpbpl] = (mp_limb_t)1 << FRAC % mpbpl; |
9a0a462c UD |
169 | exp_mpn (ex, x); |
170 | ||
171 | memset (e2, '\0', sizeof (mp1)); | |
172 | for (i = -1; i < 100 && i < FRAC / 4; i++) | |
11bf311e UD |
173 | e2[(FRAC - i * 4 - 4) / mpbpl] |= ((mp_limb_t) (strchr (hexdig, |
174 | exp1[i + 1]) | |
175 | - hexdig) | |
176 | << (FRAC - i * 4 - 4) % mpbpl); | |
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177 | |
178 | if (mpn_cmp (ex, e2, SZ) >= 0) | |
179 | mpn_sub_n (e3, ex, e2, SZ); | |
180 | else | |
181 | mpn_sub_n (e3, e2, ex, SZ); | |
182 | ||
183 | printf ("%d failures; %d errors; error rate %0.2f%%\n", failures, errors, | |
184 | errors * 100.0 / (double) (1 << N2)); | |
185 | fputs ("maximum error: ", stdout); | |
186 | print_mpn_hex (maxerror, (FRAC / 4) + 1); | |
187 | fputs ("\nerror in exp(1): ", stdout); | |
188 | print_mpn_hex (e3, (FRAC / 4) + 1); | |
189 | putchar ('\n'); | |
190 | ||
191 | return failures == 0 ? 0 : 1; | |
192 | } | |
29955b5d | 193 | |
95296112 | 194 | #define TIMEOUT 200 |
29955b5d AS |
195 | #define TEST_FUNCTION do_test () |
196 | #include "../test-skeleton.c" |