X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Ffabsf.m4;h=c1415074c8fc9aa3767fd9e0d8122c20a5b4835e;hb=fa1db0dd22768f09a507674a30beb5b8a87bb35f;hp=7924758138a88685e0428d220435865719b35c44;hpb=7f26f4f75fc3aee7a5e351ecdf05278d9890ff3e;p=gnulib.git

diff --git a/m4/fabsf.m4 b/m4/fabsf.m4
index 792475813..c1415074c 100644
--- 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) 2011-2013 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.
@@ -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