1 /* Test of multiplying a 'long double' by a power of 2.
2 Copyright (C) 2007-2010 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. */
23 #include "signature.h"
24 SIGNATURE_CHECK (ldexpl, long double, (long double, int));
29 #include "isnanl-nolibm.h"
33 /* On HP-UX 10.20, negating 0.0L does not yield -0.0L.
34 So we use minus_zero instead.
35 IRIX cc can't put -0.0L into .data, but can compute at runtime.
36 Note that the expression -LDBL_MIN * LDBL_MIN does not work on other
37 platforms, such as when cross-compiling to PowerPC on MacOS X 10.5. */
38 #if defined __hpux || defined __sgi
40 compute_minus_zero (void)
42 return -LDBL_MIN * LDBL_MIN;
44 # define minus_zero compute_minus_zero ()
46 long double minus_zero = -0.0L;
55 DECL_LONG_DOUBLE_ROUNDING
57 BEGIN_LONG_DOUBLE_ROUNDING ();
61 y = ldexpl (x, 0); ASSERT (isnanl (y));
62 y = ldexpl (x, 5); ASSERT (isnanl (y));
63 y = ldexpl (x, -5); ASSERT (isnanl (y));
66 { /* Positive infinity. */
68 y = ldexpl (x, 0); ASSERT (y == x);
69 y = ldexpl (x, 5); ASSERT (y == x);
70 y = ldexpl (x, -5); ASSERT (y == x);
73 { /* Negative infinity. */
75 y = ldexpl (x, 0); ASSERT (y == x);
76 y = ldexpl (x, 5); ASSERT (y == x);
77 y = ldexpl (x, -5); ASSERT (y == x);
80 { /* Positive zero. */
82 y = ldexpl (x, 0); ASSERT (y == x); ASSERT (!signbit (x));
83 y = ldexpl (x, 5); ASSERT (y == x); ASSERT (!signbit (x));
84 y = ldexpl (x, -5); ASSERT (y == x); ASSERT (!signbit (x));
87 { /* Negative zero. */
89 y = ldexpl (x, 0); ASSERT (y == x); ASSERT (signbit (x));
90 y = ldexpl (x, 5); ASSERT (y == x); ASSERT (signbit (x));
91 y = ldexpl (x, -5); ASSERT (y == x); ASSERT (signbit (x));
94 { /* Positive finite number. */
96 y = ldexpl (x, 0); ASSERT (y == x);
97 y = ldexpl (x, 5); ASSERT (y == x * 32.0L);
98 y = ldexpl (x, -5); ASSERT (y == x * 0.03125L);
101 { /* Negative finite number. */
102 x = -20.085536923187667742L;
103 y = ldexpl (x, 0); ASSERT (y == x);
104 y = ldexpl (x, 5); ASSERT (y == x * 32.0L);
105 y = ldexpl (x, -5); ASSERT (y == x * 0.03125L);
108 for (i = 1, x = 1.73205L; i <= LDBL_MAX_EXP; i++, x *= 2.0L)
110 y = ldexpl (x, 0); ASSERT (y == x);
111 y = ldexpl (x, 5); ASSERT (y == x * 32.0L);
112 y = ldexpl (x, -5); ASSERT (y == x * 0.03125L);
114 for (i = 1, x = 1.73205L; i >= LDBL_MIN_EXP; i--, x *= 0.5L)
116 y = ldexpl (x, 0); ASSERT (y == x);
117 y = ldexpl (x, 5); ASSERT (y == x * 32.0L);
118 if (i - 5 >= LDBL_MIN_EXP)
120 y = ldexpl (x, -5); ASSERT (y == x * 0.03125L);
123 for (; i >= LDBL_MIN_EXP - 100 && x > 0.0L; i--, x *= 0.5L)
125 y = ldexpl (x, 0); ASSERT (y == x);
126 y = ldexpl (x, 5); ASSERT (y == x * 32.0L);