* m4/logf-ieee.m4: New file.
* m4/logf.m4 (gl_FUNC_LOGF): If gl_FUNC_LOGF_IEEE is present, test
whether logf works with a negative argument. Replace it if not.
* lib/logf.c (logf): For negative arguments, return NaN.
* modules/logf-ieee (Files): Add m4/logf-ieee.m4.
(configure.ac): Invoke gl_FUNC_LOGF_IEEE.
* doc/posix-functions/logf.texi: Mention the logf-ieee module.
2012-03-10 Bruno Haible <bruno@clisp.org>
+ logf-ieee: Work around test failure on NetBSD 5.1.
+ * m4/logf-ieee.m4: New file.
+ * m4/logf.m4 (gl_FUNC_LOGF): If gl_FUNC_LOGF_IEEE is present, test
+ whether logf works with a negative argument. Replace it if not.
+ * lib/logf.c (logf): For negative arguments, return NaN.
+ * modules/logf-ieee (Files): Add m4/logf-ieee.m4.
+ (configure.ac): Invoke gl_FUNC_LOGF_IEEE.
+ * doc/posix-functions/logf.texi: Mention the logf-ieee module.
+
logf-ieee: Work around test failure on Solaris 9.
* modules/logf-ieee (Depends-on): Add log-ieee.
(configure.ac): Require gl_FUNC_LOGF.
POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/logf.html}
-Gnulib module: logf
+Gnulib module: logf or logf-ieee
-Portability problems fixed by Gnulib:
+Portability problems fixed by either Gnulib module @code{logf} or @code{logf-ieee}:
@itemize
@item
This function is missing on some platforms:
OSF/1 5.1.
@end itemize
+Portability problems fixed by Gnulib module @code{logf-ieee}:
+@itemize
+@item
+This function returns a wrong value for a negative argument on some platforms:
+NetBSD 5.1.
+@end itemize
+
Portability problems not fixed by Gnulib:
@itemize
@end itemize
#undef logf
{
#if HAVE_LOGF
- /* Work around the OSF/1 5.1 bug. */
- if (x == 0.0f)
- /* Return -Infinity. */
- return -1.0f / 0.0f;
+ if (x <= 0.0f)
+ {
+ /* Work around the OSF/1 5.1 bug. */
+ if (x == 0.0f)
+ /* Return -Infinity. */
+ return -1.0f / 0.0f;
+ /* Work around the NetBSD 5.1 bug. */
+ else /* x < 0.0 */
+ /* Return NaN. */
+ return 0.0f / 0.0f;
+ }
return logf (x);
#else
return (float) log ((double) x);
--- /dev/null
+# logf-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_LOGF can test whether 'aclocal' has
+dnl found uses of this macro.
+
+AC_DEFUN([gl_FUNC_LOGF_IEEE],
+[
+ m4_divert_text([INIT_PREPARE], [gl_logf_required=ieee])
+ AC_REQUIRE([gl_FUNC_LOGF])
+])
-# logf.m4 serial 3
+# logf.m4 serial 4
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_LOGF],
[
+ m4_divert_text([DEFAULTS], [gl_logf_required=plain])
AC_REQUIRE([gl_MATH_H_DEFAULTS])
AC_REQUIRE([gl_FUNC_LOG])
LIBS="$save_LIBS"
if test $ac_cv_func_logf = yes; then
LOGF_LIBM="$LOG_LIBM"
+
save_LIBS="$LIBS"
LIBS="$LIBS $LOGF_LIBM"
gl_FUNC_LOGF_WORKS
*yes) ;;
*) REPLACE_LOGF=1 ;;
esac
+
+ m4_ifdef([gl_FUNC_LOGF_IEEE], [
+ if test $gl_logf_required = ieee && test $REPLACE_LOGF = 0; then
+ AC_CACHE_CHECK([whether logf works according to ISO C 99 with IEC 60559],
+ [gl_cv_func_logf_ieee],
+ [
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $LOGF_LIBM"
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <math.h>
+/* Compare two numbers with ==.
+ This is a separate function because IRIX 6.5 "cc -O" miscompiles an
+ 'x == x' test. */
+static int
+numeric_equal (float x, float y)
+{
+ return x == y;
+}
+static float dummy (float x) { return 0; }
+int main (int argc, char *argv[])
+{
+ float (*my_log) (float) = argc ? logf : dummy;
+ /* Test logf(negative).
+ This test fails on NetBSD 5.1. */
+ float y = my_logf (-1.0f);
+ if (numeric_equal (y, y))
+ return 1;
+ return 0;
+}
+ ]])],
+ [gl_cv_func_logf_ieee=yes],
+ [gl_cv_func_logf_ieee=no],
+ [gl_cv_func_logf_ieee="guessing no"])
+ LIBS="$save_LIBS"
+ ])
+ case "$gl_cv_func_logf_ieee" in
+ *yes) ;;
+ *) REPLACE_LOGF=1 ;;
+ esac
+ fi
+ ])
else
HAVE_LOGF=0
fi
logf() function according to ISO C 99 with IEC 60559.
Files:
+m4/logf-ieee.m4
Depends-on:
logf
log-ieee [test $HAVE_LOGF = 0 || test $REPLACE_LOGF = 1]
configure.ac:
-AC_REQUIRE([gl_FUNC_LOGF])
+gl_FUNC_LOGF_IEEE
Makefile.am: