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/* Test of splitting a 'long double' into fraction and mantissa.
Copyright (C) 2007-2009 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Written by Bruno Haible <bruno@clisp.org>, 2007. */
#include <config.h>
#include <math.h>
#include <float.h>
#include <stdio.h>
#include <stdlib.h>
#include "fpucw.h"
#include "isnanl-nolibm.h"
#include "nan.h"
/* Avoid some warnings from "gcc -Wshadow".
This file doesn't use the exp() function. */
#undef exp
#define exp exponent
#define ASSERT(expr) \
do \
{ \
if (!(expr)) \
{ \
fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
fflush (stderr); \
abort (); \
} \
} \
while (0)
/* On MIPS IRIX machines, LDBL_MIN_EXP is -1021, but the smallest reliable
exponent for 'long double' is -964. Similarly, on PowerPC machines,
LDBL_MIN_EXP is -1021, but the smallest reliable exponent for 'long double'
is -968. For exponents below that, the precision may be truncated to the
precision used for 'double'. */
#ifdef __sgi
# define MIN_NORMAL_EXP (LDBL_MIN_EXP + 57)
#elif defined __ppc || defined __ppc__ || defined __powerpc || defined __powerpc__
# define MIN_NORMAL_EXP (LDBL_MIN_EXP + 53)
#else
# define MIN_NORMAL_EXP LDBL_MIN_EXP
#endif
/* On HP-UX 10.20, negating 0.0L does not yield -0.0L.
So we use minus_zero instead.
IRIX cc can't put -0.0L into .data, but can compute at runtime.
Note that the expression -LDBL_MIN * LDBL_MIN does not work on other
platforms, such as when cross-compiling to PowerPC on MacOS X 10.5. */
#if defined __hpux || defined __sgi
static long double
compute_minus_zero (void)
{
return -LDBL_MIN * LDBL_MIN;
}
# define minus_zero compute_minus_zero ()
#else
long double minus_zero = -0.0L;
#endif
static long double
my_ldexp (long double x, int d)
{
for (; d > 0; d--)
x *= 2.0L;
for (; d < 0; d++)
x *= 0.5L;
return x;
}
int
main ()
{
int i;
long double x;
DECL_LONG_DOUBLE_ROUNDING
BEGIN_LONG_DOUBLE_ROUNDING ();
{ /* NaN. */
int exp = -9999;
long double mantissa;
x = NaNl ();
mantissa = frexpl (x, &exp);
ASSERT (isnanl (mantissa));
}
{ /* Positive infinity. */
int exp = -9999;
long double mantissa;
x = 1.0L / 0.0L;
mantissa = frexpl (x, &exp);
ASSERT (mantissa == x);
}
{ /* Negative infinity. */
int exp = -9999;
long double mantissa;
x = -1.0L / 0.0L;
mantissa = frexpl (x, &exp);
ASSERT (mantissa == x);
}
{ /* Positive zero. */
int exp = -9999;
long double mantissa;
x = 0.0L;
mantissa = frexpl (x, &exp);
ASSERT (exp == 0);
ASSERT (mantissa == x);
ASSERT (!signbit (mantissa));
}
{ /* Negative zero. */
int exp = -9999;
long double mantissa;
x = minus_zero;
mantissa = frexpl (x, &exp);
ASSERT (exp == 0);
ASSERT (mantissa == x);
ASSERT (signbit (mantissa));
}
for (i = 1, x = 1.0L; i <= LDBL_MAX_EXP; i++, x *= 2.0L)
{
int exp = -9999;
long double mantissa = frexpl (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == 0.5L);
}
for (i = 1, x = 1.0L; i >= MIN_NORMAL_EXP; i--, x *= 0.5L)
{
int exp = -9999;
long double mantissa = frexpl (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == 0.5L);
}
for (; i >= LDBL_MIN_EXP - 100 && x > 0.0L; i--, x *= 0.5L)
{
int exp = -9999;
long double mantissa = frexpl (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == 0.5L);
}
for (i = 1, x = -1.0L; i <= LDBL_MAX_EXP; i++, x *= 2.0L)
{
int exp = -9999;
long double mantissa = frexpl (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == -0.5L);
}
for (i = 1, x = -1.0L; i >= MIN_NORMAL_EXP; i--, x *= 0.5L)
{
int exp = -9999;
long double mantissa = frexpl (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == -0.5L);
}
for (; i >= LDBL_MIN_EXP - 100 && x < 0.0L; i--, x *= 0.5L)
{
int exp = -9999;
long double mantissa = frexpl (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == -0.5L);
}
for (i = 1, x = 1.01L; i <= LDBL_MAX_EXP; i++, x *= 2.0L)
{
int exp = -9999;
long double mantissa = frexpl (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == 0.505L);
}
for (i = 1, x = 1.01L; i >= MIN_NORMAL_EXP; i--, x *= 0.5L)
{
int exp = -9999;
long double mantissa = frexpl (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == 0.505L);
}
for (; i >= LDBL_MIN_EXP - 100 && x > 0.0L; i--, x *= 0.5L)
{
int exp = -9999;
long double mantissa = frexpl (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa >= 0.5L);
ASSERT (mantissa < 1.0L);
ASSERT (mantissa == my_ldexp (x, - exp));
}
for (i = 1, x = 1.73205L; i <= LDBL_MAX_EXP; i++, x *= 2.0L)
{
int exp = -9999;
long double mantissa = frexpl (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == 0.866025L);
}
for (i = 1, x = 1.73205L; i >= MIN_NORMAL_EXP; i--, x *= 0.5L)
{
int exp = -9999;
long double mantissa = frexpl (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == 0.866025L);
}
for (; i >= LDBL_MIN_EXP - 100 && x > 0.0L; i--, x *= 0.5L)
{
int exp = -9999;
long double mantissa = frexpl (x, &exp);
ASSERT (exp == i || exp == i + 1);
ASSERT (mantissa >= 0.5L);
ASSERT (mantissa < 1.0L);
ASSERT (mantissa == my_ldexp (x, - exp));
}
return 0;
}
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