Tests for module 'printf-frexp'.

ChangeLog

@@ -1,5 +1,8 @@
 2007-02-25  Bruno Haible  <bruno@clisp.org>
 
+	* modules/printf-frexp-tests: New file.
+	* tests/test-printf-frexp.c: New file.
+
 	* modules/printf-frexp: New file.
 	* lib/printf-frexp.h: New file.
 	* lib/printf-frexp.c: New file.

modules/printf-frexp-tests

@@ -0,0 +1,13 @@
+Files:
+tests/test-printf-frexp.c
+
+Depends-on:
+
+configure.ac:
+
+Makefile.am:
+TESTS += test-printf-frexp
+check_PROGRAMS += test-printf-frexp
+
+License:
+LGPL

tests/test-printf-frexp.c

@@ -0,0 +1,116 @@
+/* Test of splitting a 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 "printf-frexp.h"
+
+#include <float.h>
+#include <stdlib.h>
+
+#define ASSERT(expr) if (!(expr)) abort ();
+
+static double
+my_ldexp (double x, int d)
+{
+  for (; d > 0; d--)
+    x *= 2.0;
+  for (; d < 0; d++)
+    x *= 0.5;
+  return x;
+}
+
+int
+main ()
+{
+  int i;
+  double x;
+
+  for (i = 1, x = 1.0; i <= DBL_MAX_EXP; i++, x *= 2.0)
+    {
+      int exp = -9999;
+      double mantissa = printf_frexp (x, &exp);
+      ASSERT (exp == i - 1);
+      ASSERT (mantissa == 1.0);
+    }
+  for (i = 1, x = 1.0; i >= DBL_MIN_EXP; i--, x *= 0.5)
+    {
+      int exp = -9999;
+      double mantissa = printf_frexp (x, &exp);
+      ASSERT (exp == i - 1);
+      ASSERT (mantissa == 1.0);
+    }
+  for (; i >= DBL_MIN_EXP - 100 && x > 0.0; i--, x *= 0.5)
+    {
+      int exp = -9999;
+      double mantissa = printf_frexp (x, &exp);
+      ASSERT (exp == DBL_MIN_EXP - 1);
+      ASSERT (mantissa == my_ldexp (1.0, i - DBL_MIN_EXP));
+    }
+
+  for (i = 1, x = 1.01; i <= DBL_MAX_EXP; i++, x *= 2.0)
+    {
+      int exp = -9999;
+      double mantissa = printf_frexp (x, &exp);
+      ASSERT (exp == i - 1);
+      ASSERT (mantissa == 1.01);
+    }
+  for (i = 1, x = 1.01; i >= DBL_MIN_EXP; i--, x *= 0.5)
+    {
+      int exp = -9999;
+      double mantissa = printf_frexp (x, &exp);
+      ASSERT (exp == i - 1);
+      ASSERT (mantissa == 1.01);
+    }
+  for (; i >= DBL_MIN_EXP - 100 && x > 0.0; i--, x *= 0.5)
+    {
+      int exp = -9999;
+      double mantissa = printf_frexp (x, &exp);
+      ASSERT (exp == DBL_MIN_EXP - 1);
+      ASSERT (mantissa >= my_ldexp (1.0, i - DBL_MIN_EXP));
+      ASSERT (mantissa <= my_ldexp (2.0, i - DBL_MIN_EXP));
+      ASSERT (mantissa == my_ldexp (x, - exp));
+    }
+
+  for (i = 1, x = 1.73205; i <= DBL_MAX_EXP; i++, x *= 2.0)
+    {
+      int exp = -9999;
+      double mantissa = printf_frexp (x, &exp);
+      ASSERT (exp == i - 1);
+      ASSERT (mantissa == 1.73205);
+    }
+  for (i = 1, x = 1.73205; i >= DBL_MIN_EXP; i--, x *= 0.5)
+    {
+      int exp = -9999;
+      double mantissa = printf_frexp (x, &exp);
+      ASSERT (exp == i - 1);
+      ASSERT (mantissa == 1.73205);
+    }
+  for (; i >= DBL_MIN_EXP - 100 && x > 0.0; i--, x *= 0.5)
+    {
+      int exp = -9999;
+      double mantissa = printf_frexp (x, &exp);
+      ASSERT (exp == DBL_MIN_EXP - 1);
+      ASSERT (mantissa >= my_ldexp (1.0, i - DBL_MIN_EXP));
+      ASSERT (mantissa <= my_ldexp (2.0, i - DBL_MIN_EXP));
+      ASSERT (mantissa == my_ldexp (x, - exp));
+    }
+
+  return 0;
+}