-# copysignl.m4 serial 1
-dnl Copyright (C) 2011 Free Software Foundation, Inc.
+# copysignl.m4 serial 3
+dnl Copyright (C) 2011-2013 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_COPYSIGNL],
[
AC_REQUIRE([gl_MATH_H_DEFAULTS])
+ AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
+
+ dnl Persuade glibc <math.h> to declare copysignl().
+ AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
dnl Determine COPYSIGNL_LIBM.
gl_MATHFUNC([copysignl], [long double], [(long double, long double)])
if test $gl_cv_func_copysignl_no_libm = no \
&& test $gl_cv_func_copysignl_in_libm = no; then
HAVE_COPYSIGNL=0
- COPYSIGNL_LIBM=
+ if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
+ AC_REQUIRE([gl_FUNC_COPYSIGN])
+ COPYSIGNL_LIBM="$COPYSIGN_LIBM"
+ else
+ COPYSIGNL_LIBM=
+ fi
fi
AC_SUBST([COPYSIGNL_LIBM])
])