1/* Test of splitting a 'long double' into fraction and mantissa.
2   Copyright (C) 2007-2010 Free Software Foundation, Inc.
3
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.
8
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.
13
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/>.  */
16
17/* Written by Bruno Haible <bruno@clisp.org>, 2007.  */
18
19#include <config.h>
20
21#include "printf-frexpl.h"
22
23#include <float.h>
24
25#include "fpucw.h"
26#include "macros.h"
27
28/* On MIPS IRIX machines, LDBL_MIN_EXP is -1021, but the smallest reliable
29   exponent for 'long double' is -964.  Similarly, on PowerPC machines,
30   LDBL_MIN_EXP is -1021, but the smallest reliable exponent for 'long double'
31   is -968.  For exponents below that, the precision may be truncated to the
32   precision used for 'double'.  */
33#ifdef __sgi
34# define MIN_NORMAL_EXP (LDBL_MIN_EXP + 57)
35# define MIN_SUBNORMAL_EXP MIN_NORMAL_EXP
36#elif defined __ppc || defined __ppc__ || defined __powerpc || defined __powerpc__
37# define MIN_NORMAL_EXP (LDBL_MIN_EXP + 53)
38# define MIN_SUBNORMAL_EXP MIN_NORMAL_EXP
39#else
40# define MIN_NORMAL_EXP LDBL_MIN_EXP
41# define MIN_SUBNORMAL_EXP (LDBL_MIN_EXP - 100)
42#endif
43
44static long double
45my_ldexp (long double x, int d)
46{
47  for (; d > 0; d--)
48    x *= 2.0L;
49  for (; d < 0; d++)
50    x *= 0.5L;
51  return x;
52}
53
54int
55main ()
56{
57  int i;
58  long double x;
59  DECL_LONG_DOUBLE_ROUNDING
60
61  BEGIN_LONG_DOUBLE_ROUNDING ();
62
63  for (i = 1, x = 1.0L; i <= LDBL_MAX_EXP; i++, x *= 2.0L)
64    {
65      int exp = -9999;
66      long double mantissa = printf_frexpl (x, &exp);
67      ASSERT (exp == i - 1);
68      ASSERT (mantissa == 1.0L);
69    }
70  for (i = 1, x = 1.0L; i >= MIN_NORMAL_EXP; i--, x *= 0.5L)
71    {
72      int exp = -9999;
73      long double mantissa = printf_frexpl (x, &exp);
74      ASSERT (exp == i - 1);
75      ASSERT (mantissa == 1.0L);
76    }
77  for (; i >= MIN_SUBNORMAL_EXP && x > 0.0L; i--, x *= 0.5L)
78    {
79      int exp = -9999;
80      long double mantissa = printf_frexpl (x, &exp);
81      ASSERT (exp == LDBL_MIN_EXP - 1);
82      ASSERT (mantissa == my_ldexp (1.0L, i - LDBL_MIN_EXP));
83    }
84
85  for (i = 1, x = 1.01L; i <= LDBL_MAX_EXP; i++, x *= 2.0L)
86    {
87      int exp = -9999;
88      long double mantissa = printf_frexpl (x, &exp);
89      ASSERT (exp == i - 1);
90      ASSERT (mantissa == 1.01L);
91    }
92  for (i = 1, x = 1.01L; i >= MIN_NORMAL_EXP; i--, x *= 0.5L)
93    {
94      int exp = -9999;
95      long double mantissa = printf_frexpl (x, &exp);
96      ASSERT (exp == i - 1);
97      ASSERT (mantissa == 1.01L);
98    }
99  for (; i >= MIN_SUBNORMAL_EXP && x > 0.0L; i--, x *= 0.5L)
100    {
101      int exp = -9999;
102      long double mantissa = printf_frexpl (x, &exp);
103      ASSERT (exp == LDBL_MIN_EXP - 1);
104      ASSERT (mantissa >= my_ldexp (1.0L, i - LDBL_MIN_EXP));
105      ASSERT (mantissa <= my_ldexp (2.0L, i - LDBL_MIN_EXP));
106      ASSERT (mantissa == my_ldexp (x, - exp));
107    }
108
109  for (i = 1, x = 1.73205L; i <= LDBL_MAX_EXP; i++, x *= 2.0L)
110    {
111      int exp = -9999;
112      long double mantissa = printf_frexpl (x, &exp);
113      ASSERT (exp == i - 1);
114      ASSERT (mantissa == 1.73205L);
115    }
116  for (i = 1, x = 1.73205L; i >= MIN_NORMAL_EXP; i--, x *= 0.5L)
117    {
118      int exp = -9999;
119      long double mantissa = printf_frexpl (x, &exp);
120      ASSERT (exp == i - 1);
121      ASSERT (mantissa == 1.73205L);
122    }
123  for (; i >= MIN_SUBNORMAL_EXP && x > 0.0L; i--, x *= 0.5L)
124    {
125      int exp = -9999;
126      long double mantissa = printf_frexpl (x, &exp);
127      ASSERT (exp == LDBL_MIN_EXP - 1);
128      ASSERT (mantissa >= my_ldexp (1.0L, i - LDBL_MIN_EXP));
129      ASSERT (mantissa <= my_ldexp (2.0L, i - LDBL_MIN_EXP));
130      ASSERT (mantissa == my_ldexp (x, - exp));
131    }
132
133  return 0;
134}
135