1 /* Test of multiplying a 'long double' by a power of 2.
2 Copyright (C) 2007-2008 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/>. */
17 /* Written by Bruno Haible <bruno@clisp.org>, 2007. */
28 #include "isnanl-nolibm.h"
30 #define ASSERT(expr) \
35 fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
42 /* On HP-UX 10.20, negating 0.0L does not yield -0.0L.
43 So we use minus_zero instead.
44 Note that the expression -LDBL_MIN * LDBL_MIN does not work on other
45 platforms, such as when cross-compiling to PowerPC on MacOS X 10.5. */
46 #if defined __hpux || defined __sgi
47 long double minus_zero = -LDBL_MIN * LDBL_MIN;
49 long double minus_zero = -0.0L;
58 DECL_LONG_DOUBLE_ROUNDING
60 BEGIN_LONG_DOUBLE_ROUNDING ();
64 y = ldexpl (x, 0); ASSERT (isnanl (y));
65 y = ldexpl (x, 5); ASSERT (isnanl (y));
66 y = ldexpl (x, -5); ASSERT (isnanl (y));
69 { /* Positive infinity. */
71 y = ldexpl (x, 0); ASSERT (y == x);
72 y = ldexpl (x, 5); ASSERT (y == x);
73 y = ldexpl (x, -5); ASSERT (y == x);
76 { /* Negative infinity. */
78 y = ldexpl (x, 0); ASSERT (y == x);
79 y = ldexpl (x, 5); ASSERT (y == x);
80 y = ldexpl (x, -5); ASSERT (y == x);
83 { /* Positive zero. */
85 y = ldexpl (x, 0); ASSERT (y == x); ASSERT (!signbit (x));
86 y = ldexpl (x, 5); ASSERT (y == x); ASSERT (!signbit (x));
87 y = ldexpl (x, -5); ASSERT (y == x); ASSERT (!signbit (x));
90 { /* Negative zero. */
92 y = ldexpl (x, 0); ASSERT (y == x); ASSERT (signbit (x));
93 y = ldexpl (x, 5); ASSERT (y == x); ASSERT (signbit (x));
94 y = ldexpl (x, -5); ASSERT (y == x); ASSERT (signbit (x));
97 { /* Positive finite number. */
99 y = ldexpl (x, 0); ASSERT (y == x);
100 y = ldexpl (x, 5); ASSERT (y == x * 32.0L);
101 y = ldexpl (x, -5); ASSERT (y == x * 0.03125L);
104 { /* Negative finite number. */
105 x = -20.085536923187667742L;
106 y = ldexpl (x, 0); ASSERT (y == x);
107 y = ldexpl (x, 5); ASSERT (y == x * 32.0L);
108 y = ldexpl (x, -5); ASSERT (y == x * 0.03125L);
111 for (i = 1, x = 1.73205L; i <= LDBL_MAX_EXP; i++, x *= 2.0L)
113 y = ldexpl (x, 0); ASSERT (y == x);
114 y = ldexpl (x, 5); ASSERT (y == x * 32.0L);
115 y = ldexpl (x, -5); ASSERT (y == x * 0.03125L);
117 for (i = 1, x = 1.73205L; i >= LDBL_MIN_EXP; i--, x *= 0.5L)
119 y = ldexpl (x, 0); ASSERT (y == x);
120 y = ldexpl (x, 5); ASSERT (y == x * 32.0L);
121 if (i - 5 >= LDBL_MIN_EXP)
123 y = ldexpl (x, -5); ASSERT (y == x * 0.03125L);
126 for (; i >= LDBL_MIN_EXP - 100 && x > 0.0L; i--, x *= 0.5L)
128 y = ldexpl (x, 0); ASSERT (y == x);
129 y = ldexpl (x, 5); ASSERT (y == x * 32.0L);