--- /dev/null
+/* Test of splitting a 'long double' into fraction and mantissa.
+ Copyright (C) 2007 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 2, 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, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2007. */
+
+#include <config.h>
+
+#include <math.h>
+
+#include <float.h>
+#include <stdlib.h>
+
+#define ASSERT(expr) if (!(expr)) abort ();
+
+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;
+
+ { /* NaN. */
+ int exp = -9999;
+ long double mantissa;
+ x = 0.0L / 0.0L;
+ mantissa = frexpl (x, &exp);
+ ASSERT (mantissa != 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);
+ }
+
+ { /* Negative zero. */
+ int exp = -9999;
+ long double mantissa;
+ x = -0.0L;
+ mantissa = frexpl (x, &exp);
+ ASSERT (exp == 0);
+ ASSERT (mantissa == x);
+ }
+
+ 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 >= LDBL_MIN_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 >= LDBL_MIN_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 >= LDBL_MIN_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 >= LDBL_MIN_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;
+}