-# log10f.m4 serial 3
-dnl Copyright (C) 2011-2012 Free Software Foundation, Inc.
+# log10f.m4 serial 6
+dnl Copyright (C) 2011-2014 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.
AC_DEFUN([gl_FUNC_LOG10F],
[
+ m4_divert_text([DEFAULTS], [gl_log10f_required=plain])
AC_REQUIRE([gl_MATH_H_DEFAULTS])
AC_REQUIRE([gl_FUNC_LOG10])
*yes) ;;
*) REPLACE_LOG10F=1 ;;
esac
+
+ m4_ifdef([gl_FUNC_LOG10F_IEEE], [
+ if test $gl_log10f_required = ieee && test $REPLACE_LOG10F = 0; then
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CACHE_CHECK([whether log10f works according to ISO C 99 with IEC 60559],
+ [gl_cv_func_log10f_ieee],
+ [
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $LOG10F_LIBM"
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <math.h>
+/* Compare two numbers with ==.
+ This is a separate function because IRIX 6.5 "cc -O" miscompiles an
+ 'x == x' test. */
+static int
+numeric_equal (float x, float y)
+{
+ return x == y;
+}
+static float dummy (float x) { return 0; }
+int main (int argc, char *argv[])
+{
+ float (*my_log10f) (float) = argc ? log10f : dummy;
+ /* Test log10f(negative).
+ This test fails on NetBSD 5.1. */
+ float y = my_log10f (-1.0f);
+ if (numeric_equal (y, y))
+ return 1;
+ return 0;
+}
+ ]])],
+ [gl_cv_func_log10f_ieee=yes],
+ [gl_cv_func_log10f_ieee=no],
+ [case "$host_os" in
+ # Guess yes on glibc systems.
+ *-gnu*) gl_cv_func_log10f_ieee="guessing yes" ;;
+ # If we don't know, assume the worst.
+ *) gl_cv_func_log10f_ieee="guessing no" ;;
+ esac
+ ])
+ LIBS="$save_LIBS"
+ ])
+ case "$gl_cv_func_log10f_ieee" in
+ *yes) ;;
+ *) REPLACE_LOG10F=1 ;;
+ esac
+ fi
+ ])
else
HAVE_LOG10F=0
fi