* m4/log10-ieee.m4: New file.
* m4/log10.m4 (gl_FUNC_LOG10): If gl_FUNC_LOG10_IEEE is present, test
whether log10 works with a negative argument. Replace it if not.
* lib/log10.c (log10): For negative arguments, return NaN.
* modules/log10-ieee (Files): Add m4/log10-ieee.m4.
(configure.ac): Invoke gl_FUNC_LOG10_IEEE.
* doc/posix-functions/log10.texi: Mention the log10-ieee module.
2012-04-01 Bruno Haible <bruno@clisp.org>
+ log10-ieee: Work around test failure on NetBSD 5.1 and Solaris 11.
+ * m4/log10-ieee.m4: New file.
+ * m4/log10.m4 (gl_FUNC_LOG10): If gl_FUNC_LOG10_IEEE is present, test
+ whether log10 works with a negative argument. Replace it if not.
+ * lib/log10.c (log10): For negative arguments, return NaN.
+ * modules/log10-ieee (Files): Add m4/log10-ieee.m4.
+ (configure.ac): Invoke gl_FUNC_LOG10_IEEE.
+ * doc/posix-functions/log10.texi: Mention the log10-ieee module.
+
Tests for module 'log10l-ieee'.
* modules/log10l-ieee-tests: New file.
* tests/test-log10l-ieee.c: New file.
POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/log10.html}
-Gnulib module: log10
+Gnulib module: log10 or log10-ieee
-Portability problems fixed by Gnulib:
+Portability problems fixed by either Gnulib module @code{log10} or @code{log10-ieee}:
@itemize
@item
This function returns a wrong value for a minus zero argument on some platforms:
OSF/1 5.1.
@end itemize
+Portability problems fixed by Gnulib module @code{log10-ieee}:
+@itemize
+@item
+This function returns a wrong value for a negative argument on some platforms:
+NetBSD 5.1, Solaris 11 2011-11.
+@end itemize
+
Portability problems not fixed by Gnulib:
@itemize
@end itemize
log10 (double x)
#undef log10
{
- /* Work around the OSF/1 5.1 bug. */
- if (x == 0.0)
- /* Return -Infinity. */
- return -1.0 / 0.0;
+ if (x <= 0.0)
+ {
+ /* Work around the OSF/1 5.1 bug. */
+ if (x == 0.0)
+ /* Return -Infinity. */
+ return -1.0 / 0.0;
+ /* Work around the NetBSD 5.1, Solaris 11 2011-11 bug. */
+ else /* x < 0.0 */
+ /* Return NaN. */
+ return 0.0 / 0.0;
+ }
return log10 (x);
}
--- /dev/null
+# log10-ieee.m4 serial 1
+dnl Copyright (C) 2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl This macro is in a separate file (not in remainder.m4 and not inlined in the
+dnl module description), so that gl_FUNC_LOG10 can test whether 'aclocal' has
+dnl found uses of this macro.
+
+AC_DEFUN([gl_FUNC_LOG10_IEEE],
+[
+ m4_divert_text([INIT_PREPARE], [gl_log10_required=ieee])
+ AC_REQUIRE([gl_FUNC_LOG10])
+])
-# log10.m4 serial 2
+# log10.m4 serial 3
dnl Copyright (C) 2011-2012 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
AC_DEFUN([gl_FUNC_LOG10],
[
+ m4_divert_text([DEFAULTS], [gl_log10_required=plain])
AC_REQUIRE([gl_MATH_H_DEFAULTS])
dnl Determine LOG10_LIBM.
*yes) ;;
*) REPLACE_LOG10=1 ;;
esac
+
+ m4_ifdef([gl_FUNC_LOG10_IEEE], [
+ if test $gl_log10_required = ieee && test $REPLACE_LOG10 = 0; then
+ AC_CACHE_CHECK([whether log10 works according to ISO C 99 with IEC 60559],
+ [gl_cv_func_log10_ieee],
+ [
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $LOG10_LIBM"
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <math.h>
+/* Compare two numbers with ==.
+ This is a separate function because IRIX 6.5 "cc -O" miscompiles an
+ 'x == x' test. */
+static int
+numeric_equal (double x, double y)
+{
+ return x == y;
+}
+static double dummy (double x) { return 0; }
+int main (int argc, char *argv[])
+{
+ double (*my_log10) (double) = argc ? log10 : dummy;
+ /* Test log10(negative).
+ This test fails on NetBSD 5.1, Solaris 11 2011-11. */
+ double y = my_log10 (-1.0);
+ if (numeric_equal (y, y))
+ return 1;
+ return 0;
+}
+ ]])],
+ [gl_cv_func_log10_ieee=yes],
+ [gl_cv_func_log10_ieee=no],
+ [gl_cv_func_log10_ieee="guessing no"])
+ LIBS="$save_LIBS"
+ ])
+ case "$gl_cv_func_log10_ieee" in
+ *yes) ;;
+ *) REPLACE_LOG10=1 ;;
+ esac
+ fi
+ ])
])
dnl Test whether log10() works.
log10() function according to ISO C 99 with IEC 60559.
Files:
+m4/log10-ieee.m4
Depends-on:
log10
fpieee
configure.ac:
+gl_FUNC_LOG10_IEEE
Makefile.am: