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/* Test of modf*() function family.
Copyright (C) 2012-2016 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/>. */
static void
test_function (void)
{
int i;
const DOUBLE TWO_MANT_DIG =
/* Assume MANT_DIG <= 5 * 31.
Use the identity
n = floor(n/5) + floor((n+1)/5) + ... + floor((n+4)/5). */
(DOUBLE) (1U << ((MANT_DIG - 1) / 5))
* (DOUBLE) (1U << ((MANT_DIG - 1 + 1) / 5))
* (DOUBLE) (1U << ((MANT_DIG - 1 + 2) / 5))
* (DOUBLE) (1U << ((MANT_DIG - 1 + 3) / 5))
* (DOUBLE) (1U << ((MANT_DIG - 1 + 4) / 5));
/* Randomized tests. */
for (i = 0; i < SIZEOF (RANDOM); i++)
{
DOUBLE x = RANDOM[i]; /* 0.0 <= x < 1.0 */
DOUBLE y;
DOUBLE z;
y = MODF (x, &z);
ASSERT (z == L_(0.0));
ASSERT (y == x);
y = MODF (- x, &z);
ASSERT (z == L_(0.0));
ASSERT (y == - x);
y = MODF (L_(1.0) + x, &z);
ASSERT (z == L_(1.0));
y -= x;
ASSERT (y >= - L_(1.0) / TWO_MANT_DIG);
ASSERT (y <= L_(1.0) / TWO_MANT_DIG);
y = MODF (- L_(1.0) - x, &z);
ASSERT (z == - L_(1.0));
y -= - x;
ASSERT (y >= - L_(1.0) / TWO_MANT_DIG);
ASSERT (y <= L_(1.0) / TWO_MANT_DIG);
}
}
volatile DOUBLE x;
DOUBLE y;
DOUBLE z;
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