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diff --git a/tests/test-frexpl.c b/tests/test-frexpl.c
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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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