maint: update copyright

[gnulib.git] / m4 / fabsf.m4

diff --git a/m4/fabsf.m4 b/m4/fabsf.m4
index 7924758..b902deb 100644 (file)
--- a/m4/fabsf.m4
+++ b/m4/fabsf.m4
@@ -1,5 +1,5 @@
-# fabsf.m4 serial 1
-dnl Copyright (C) 2011 Free Software Foundation, Inc.
+# fabsf.m4 serial 3
+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.
@@ -9,15 +9,15 @@ AC_DEFUN([gl_FUNC_FABSF],
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
   AC_REQUIRE([gl_FUNC_FABS])
 
-  dnl Test whether fabsf() exists. Assume that fabsf(), if it exists, is
-  dnl defined in the same library as fabs().
-  save_LIBS="$LIBS"
-  LIBS="$LIBS $FABS_LIBM"
-  AC_CHECK_FUNCS([fabsf])
-  LIBS="$save_LIBS"
-  if test $ac_cv_func_fabsf = yes; then
-    FABSF_LIBM="$FABS_LIBM"
-  else
+  dnl Persuade glibc <math.h> to declare fabsf().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
+  dnl Test whether fabsf() exists. We cannot assume that fabsf(), if it
+  dnl exists, is defined in the same library as fabs(). This is not the case
+  dnl on FreeBSD, NetBSD, OpenBSD.
+  gl_MATHFUNC([fabsf], [float], [(float)])
+  if test $gl_cv_func_fabsf_no_libm = no \
+     && test $gl_cv_func_fabsf_in_libm = no; then
     HAVE_FABSF=0
     FABSF_LIBM="$FABS_LIBM"
   fi