--- /dev/null
+/* Test of ilogb() function.
+ Copyright (C) 2012 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>, 2012. */
+
+#include <config.h>
+
+#include <math.h>
+
+#include "signature.h"
+SIGNATURE_CHECK (ilogb, int, (double));
+
+#include <float.h>
+#include <limits.h>
+
+#include "minus-zero.h"
+#include "infinity.h"
+#include "nan.h"
+#include "macros.h"
+
+#undef INFINITY
+#undef NAN
+
+#define DOUBLE double
+/* The use of 'volatile' guarantees that excess precision bits are dropped
+ when dealing with denormalized numbers. It is necessary on x86 systems
+ where double-floats are not IEEE compliant by default, to avoid that the
+ results become platform and compiler option dependent. 'volatile' is a
+ portable alternative to gcc's -ffloat-store option. */
+#define VOLATILE volatile
+#define INFINITY Infinityd ()
+#define NAN NaNd ()
+#define L_(literal) literal
+#define MINUS_ZERO minus_zerod
+#define MAX_EXP DBL_MAX_EXP
+#define MIN_EXP DBL_MIN_EXP
+#define MIN_NORMAL_EXP DBL_MIN_EXP
+#define ILOGB ilogb
+#define RANDOM randomd
+#include "test-ilogb.h"
+
+int
+main ()
+{
+ test_function ();
+
+ return 0;
+}
--- /dev/null
+/* Test of ilogb*() function family.
+ Copyright (C) 2012 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;
+ int y;
+
+ /* Some particular values. */
+ x = L_(0.6);
+ y = ILOGB (x);
+ ASSERT (y == -1);
+
+ x = L_(1.2);
+ y = ILOGB (x);
+ ASSERT (y == 0);
+
+ x = L_(2.1);
+ y = ILOGB (x);
+ ASSERT (y == 1);
+
+ x = L_(3.9);
+ y = ILOGB (x);
+ ASSERT (y == 1);
+
+ x = L_(4.0);
+ y = ILOGB (x);
+ ASSERT (y == (FLT_RADIX == 2 ? 2 : 1));
+
+ x = L_(0.25);
+ y = ILOGB (x);
+ ASSERT (y == (FLT_RADIX == 2 ? -2 : -1));
+
+ /* Zero. */
+ ASSERT (ILOGB (L_(0.0)) == FP_ILOGB0);
+ ASSERT (ILOGB (MINUS_ZERO) == FP_ILOGB0);
+
+ /* Infinity. */
+ ASSERT (ILOGB (INFINITY) == INT_MAX);
+ ASSERT (ILOGB (- INFINITY) == INT_MAX);
+
+ /* NaN. */
+ ASSERT (ILOGB (NAN) == FP_ILOGBNAN);
+
+ /* From here on, this test assumes FLT_RADIX == 2. */
+
+ for (i = 1, x = L_(1.0); i <= MAX_EXP; i++, x *= L_(2.0))
+ {
+ y = ILOGB (x);
+ ASSERT (y == i - 1);
+ }
+ for (i = 1, x = L_(1.0); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5))
+ {
+ y = ILOGB (x);
+ ASSERT (y == i - 1);
+ }
+ for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5))
+ {
+ y = ILOGB (x);
+ ASSERT (y == i - 1);
+ }
+
+ for (i = 1, x = - L_(1.0); i <= MAX_EXP; i++, x *= L_(2.0))
+ {
+ y = ILOGB (x);
+ ASSERT (y == i - 1);
+ }
+ for (i = 1, x = - L_(1.0); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5))
+ {
+ y = ILOGB (x);
+ ASSERT (y == i - 1);
+ }
+ for (; i >= MIN_EXP - 100 && x < L_(0.0); i--, x *= L_(0.5))
+ {
+ y = ILOGB (x);
+ ASSERT (y == i - 1);
+ }
+
+ for (i = 1, x = L_(1.01); i <= MAX_EXP; i++, x *= L_(2.0))
+ {
+ y = ILOGB (x);
+ ASSERT (y == i - 1);
+ }
+ for (i = 1, x = L_(1.01); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5))
+ {
+ y = ILOGB (x);
+ ASSERT (y == i - 1);
+ }
+ for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5))
+ {
+ y = ILOGB (x);
+ ASSERT (y == i - 1);
+ }
+
+ for (i = 1, x = L_(1.73205); i <= MAX_EXP; i++, x *= L_(2.0))
+ {
+ y = ILOGB (x);
+ ASSERT (y == i - 1);
+ }
+ for (i = 1, x = L_(1.73205); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5))
+ {
+ y = ILOGB (x);
+ ASSERT (y == i - 1);
+ }
+ for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5))
+ {
+ y = ILOGB (x);
+ ASSERT (y == i - 1 || y == i);
+ }
+
+ /* Randomized tests. */
+ for (i = 0; i < SIZEOF (RANDOM); i++)
+ {
+ x = L_(20.0) * RANDOM[i] - L_(10.0); /* -10.0 <= x <= 10.0 */
+ if (x != L_(0.0))
+ {
+ DOUBLE abs_x = (x < L_(0.0) ? - x : x);
+ y = ILOGB (x);
+ ASSERT (abs_x >= my_ldexp (L_(1.0), y));
+ ASSERT (abs_x < my_ldexp (L_(1.0), y + 1));
+ }
+ }
+}
+
+volatile DOUBLE x;
+DOUBLE y;