1 /* Test of splitting a double into fraction and mantissa.
2 Copyright (C) 2012-2013 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18 my_ldexp (DOUBLE x, int d)
37 mantissa = FREXP (x, &exp);
38 ASSERT (ISNAN (mantissa));
41 { /* Positive infinity. */
45 mantissa = FREXP (x, &exp);
46 ASSERT (mantissa == x);
49 { /* Negative infinity. */
53 mantissa = FREXP (x, &exp);
54 ASSERT (mantissa == x);
57 { /* Positive zero. */
61 mantissa = FREXP (x, &exp);
63 ASSERT (mantissa == x);
64 ASSERT (!signbit (mantissa));
67 { /* Negative zero. */
71 mantissa = FREXP (x, &exp);
73 ASSERT (mantissa == x);
74 ASSERT (signbit (mantissa));
77 for (i = 1, x = L_(1.0); i <= MAX_EXP; i++, x *= L_(2.0))
80 DOUBLE mantissa = FREXP (x, &exp);
82 ASSERT (mantissa == L_(0.5));
84 for (i = 1, x = L_(1.0); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5))
87 DOUBLE mantissa = FREXP (x, &exp);
89 ASSERT (mantissa == L_(0.5));
91 for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5))
94 DOUBLE mantissa = FREXP (x, &exp);
96 ASSERT (mantissa == L_(0.5));
99 for (i = 1, x = - L_(1.0); i <= MAX_EXP; i++, x *= L_(2.0))
102 DOUBLE mantissa = FREXP (x, &exp);
104 ASSERT (mantissa == - L_(0.5));
106 for (i = 1, x = - L_(1.0); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5))
109 DOUBLE mantissa = FREXP (x, &exp);
111 ASSERT (mantissa == - L_(0.5));
113 for (; i >= MIN_EXP - 100 && x < L_(0.0); i--, x *= L_(0.5))
116 DOUBLE mantissa = FREXP (x, &exp);
118 ASSERT (mantissa == - L_(0.5));
121 for (i = 1, x = L_(1.01); i <= MAX_EXP; i++, x *= L_(2.0))
124 DOUBLE mantissa = FREXP (x, &exp);
126 ASSERT (mantissa == L_(0.505));
128 for (i = 1, x = L_(1.01); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5))
131 DOUBLE mantissa = FREXP (x, &exp);
133 ASSERT (mantissa == L_(0.505));
135 for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5))
138 DOUBLE mantissa = FREXP (x, &exp);
140 ASSERT (mantissa >= L_(0.5));
141 ASSERT (mantissa < L_(1.0));
142 ASSERT (mantissa == my_ldexp (x, - exp));
145 for (i = 1, x = L_(1.73205); i <= MAX_EXP; i++, x *= L_(2.0))
148 DOUBLE mantissa = FREXP (x, &exp);
150 ASSERT (mantissa == L_(0.866025));
152 for (i = 1, x = L_(1.73205); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5))
155 DOUBLE mantissa = FREXP (x, &exp);
157 ASSERT (mantissa == L_(0.866025));
159 for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5))
162 DOUBLE mantissa = FREXP (x, &exp);
163 ASSERT (exp == i || exp == i + 1);
164 ASSERT (mantissa >= L_(0.5));
165 ASSERT (mantissa < L_(1.0));
166 ASSERT (mantissa == my_ldexp (x, - exp));
169 /* Randomized tests. */
170 for (i = 0; i < SIZEOF (RANDOM); i++)
172 x = L_(20.0) * RANDOM[i] - L_(10.0); /* -10.0 <= x <= 10.0 */
175 DOUBLE mantissa = FREXP (x, &exp);
176 ASSERT (x == my_ldexp (mantissa, exp));