/* Test of splitting a double into fraction and mantissa.
Copyright (C) 2012-2018 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 <https://www.gnu.org/licenses/>. */
static DOUBLE
my_ldexp (DOUBLE x, int d)
{
for (; d > 0; d--)
x *= L_(2.0);
for (; d < 0; d++)
x *= L_(0.5);
return x;
}
static void
test_function (void)
{
int i;
VOLATILE DOUBLE x;
{ /* NaN. */
int exp = -9999;
DOUBLE mantissa;
x = NAN;
mantissa = FREXP (x, &exp);
ASSERT (ISNAN (mantissa));
}
{ /* Positive infinity. */
int exp = -9999;
DOUBLE mantissa;
x = INFINITY;
mantissa = FREXP (x, &exp);
ASSERT (mantissa == x);
}
{ /* Negative infinity. */
int exp = -9999;
DOUBLE mantissa;
x = - INFINITY;
mantissa = FREXP (x, &exp);
ASSERT (mantissa == x);
}
{ /* Positive zero. */
int exp = -9999;
DOUBLE mantissa;
x = L_(0.0);
mantissa = FREXP (x, &exp);
ASSERT (exp == 0);
ASSERT (mantissa == x);
ASSERT (!signbit (mantissa));
}
{ /* Negative zero. */
int exp = -9999;
DOUBLE mantissa;
x = MINUS_ZERO;
mantissa = FREXP (x, &exp);
ASSERT (exp == 0);
ASSERT (mantissa == x);
ASSERT (signbit (mantissa));
}
for (i = 1, x = L_(1.0); i <= MAX_EXP; i++, x *= L_(2.0))
{
int exp = -9999;
DOUBLE mantissa = FREXP (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == L_(0.5));
}
for (i = 1, x = L_(1.0); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5))
{
int exp = -9999;
DOUBLE mantissa = FREXP (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == L_(0.5));
}
for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5))
{
int exp = -9999;
DOUBLE mantissa = FREXP (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == L_(0.5));
}
for (i = 1, x = - L_(1.0); i <= MAX_EXP; i++, x *= L_(2.0))
{
int exp = -9999;
DOUBLE mantissa = FREXP (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == - L_(0.5));
}
for (i = 1, x = - L_(1.0); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5))
{
int exp = -9999;
DOUBLE mantissa = FREXP (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == - L_(0.5));
}
for (; i >= MIN_EXP - 100 && x < L_(0.0); i--, x *= L_(0.5))
{
int exp = -9999;
DOUBLE mantissa = FREXP (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == - L_(0.5));
}
for (i = 1, x = L_(1.01); i <= MAX_EXP; i++, x *= L_(2.0))
{
int exp = -9999;
DOUBLE mantissa = FREXP (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == L_(0.505));
}
for (i = 1, x = L_(1.01); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5))
{
int exp = -9999;
DOUBLE mantissa = FREXP (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == L_(0.505));
}
for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5))
{
int exp = -9999;
DOUBLE mantissa = FREXP (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa >= L_(0.5));
ASSERT (mantissa < L_(1.0));
ASSERT (mantissa == my_ldexp (x, - exp));
}
for (i = 1, x = L_(1.73205); i <= MAX_EXP; i++, x *= L_(2.0))
{
int exp = -9999;
DOUBLE mantissa = FREXP (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == L_(0.866025));
}
for (i = 1, x = L_(1.73205); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5))
{
int exp = -9999;
DOUBLE mantissa = FREXP (x, &exp);
ASSERT (exp == i);
ASSERT (mantissa == L_(0.866025));
}
for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5))
{
int exp = -9999;
DOUBLE mantissa = FREXP (x, &exp);
ASSERT (exp == i || exp == i + 1);
ASSERT (mantissa >= L_(0.5));
ASSERT (mantissa < L_(1.0));
ASSERT (mantissa == my_ldexp (x, - exp));
}
/* Randomized tests. */
for (i = 0; i < SIZEOF (RANDOM); i++)
{
x = L_(20.0) * RANDOM[i] - L_(10.0); /* -10.0 <= x <= 10.0 */
{
int exp = -9999;
DOUBLE mantissa = FREXP (x, &exp);
ASSERT (x == my_ldexp (mantissa, exp));
}
}
}