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diff --git a/tests/test-frexp.h b/tests/test-frexp.h
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+/* Test of splitting a double into fraction and mantissa.
+ Copyright (C) 2012-2015 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 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));
+ }
+ }
+}