diff --git a/llvm/autoconf/m4/func_isinf.m4 b/llvm/autoconf/m4/func_isinf.m4
new file mode 100644
index 000000000000..dc0c22e9258a
--- /dev/null
+++ b/llvm/autoconf/m4/func_isinf.m4
@@ -0,0 +1,24 @@
+#
+# This function determins if the the isinf function isavailable on this
+# platform.
+#
+AC_DEFUN([AC_FUNC_ISINF],[
+AC_SINGLE_CXX_CHECK([HAVE_ISINF_IN_MATH_H],    [ac_cv_func_isinf_in_math_h],   
+                    [isinf], [<math.h>],
+                    [#include <math.h>
+                     int foo(float f) {return isinf(f);}])
+AC_SINGLE_CXX_CHECK([HAVE_ISINF_IN_CMATH],     [ac_cv_func_isinf_in_cmath],    
+                    [isinf], [<cmath>],
+                    [#include <cmath>
+                     int foo(float f) {return isinf(f);}])
+AC_SINGLE_CXX_CHECK([HAVE_STD_ISINF_IN_CMATH], [ac_cv_func_std_isinf_in_cmath],
+                    [std::isinf], [<cmath>],
+                    [#include <cmath>
+                     using std::isinf; int foo(float f) {return isinf(f);}])
+AC_SINGLE_CXX_CHECK([HAVE_FINITE_IN_IEEEFP_H], [ac_cv_func_finite_in_ieeefp_h],
+                    [finite], [<ieeefp.h>],
+                    [#include <ieeefp.h>
+                     int foo(float f) {return finite(f);}])
+])
+
+
diff --git a/llvm/autoconf/m4/func_isnan.m4 b/llvm/autoconf/m4/func_isnan.m4
new file mode 100644
index 000000000000..8e626fe15b3b
--- /dev/null
+++ b/llvm/autoconf/m4/func_isnan.m4
@@ -0,0 +1,18 @@
+#
+# This function determines if the isnan function is available on this
+# platform.
+#
+AC_DEFUN([AC_FUNC_ISNAN],[
+AC_SINGLE_CXX_CHECK([HAVE_ISNAN_IN_MATH_H],    [ac_cv_func_isnan_in_math_h],   
+                    [isnan], [<math.h>],
+                    [#include <math.h>
+                     int foo(float f) {return isnan(f);}])
+AC_SINGLE_CXX_CHECK([HAVE_ISNAN_IN_CMATH],     [ac_cv_func_isnan_in_cmath],    
+                    [isnan], [<cmath>],
+                    [#include <cmath>
+                     int foo(float f) {return isnan(f);}])
+AC_SINGLE_CXX_CHECK([HAVE_STD_ISNAN_IN_CMATH], [ac_cv_func_std_isnan_in_cmath],
+                    [std::isnan], [<cmath>],
+                    [#include <cmath>
+                     using std::isnan; int foo(float f) {return isnan(f);}])
+])
diff --git a/llvm/autoconf/m4/single_cxx_check.m4 b/llvm/autoconf/m4/single_cxx_check.m4
index c5e4b199c670..77ebf38657be 100644
--- a/llvm/autoconf/m4/single_cxx_check.m4
+++ b/llvm/autoconf/m4/single_cxx_check.m4
@@ -12,37 +12,3 @@ AC_DEFUN([AC_SINGLE_CXX_CHECK],
                      header file.])
  fi])
 
-AC_DEFUN([AC_FUNC_ISNAN],[
-AC_SINGLE_CXX_CHECK([HAVE_ISNAN_IN_MATH_H],    [ac_cv_func_isnan_in_math_h],   
-                    [isnan], [<math.h>],
-                    [#include <math.h>
-                     int foo(float f) {return isnan(f);}])
-AC_SINGLE_CXX_CHECK([HAVE_ISNAN_IN_CMATH],     [ac_cv_func_isnan_in_cmath],    
-                    [isnan], [<cmath>],
-                    [#include <cmath>
-                     int foo(float f) {return isnan(f);}])
-AC_SINGLE_CXX_CHECK([HAVE_STD_ISNAN_IN_CMATH], [ac_cv_func_std_isnan_in_cmath],
-                    [std::isnan], [<cmath>],
-                    [#include <cmath>
-                     using std::isnan; int foo(float f) {return isnan(f);}])
-])
-
-AC_DEFUN([AC_FUNC_ISINF],[
-AC_SINGLE_CXX_CHECK([HAVE_ISINF_IN_MATH_H],    [ac_cv_func_isinf_in_math_h],   
-                    [isinf], [<math.h>],
-                    [#include <math.h>
-                     int foo(float f) {return isinf(f);}])
-AC_SINGLE_CXX_CHECK([HAVE_ISINF_IN_CMATH],     [ac_cv_func_isinf_in_cmath],    
-                    [isinf], [<cmath>],
-                    [#include <cmath>
-                     int foo(float f) {return isinf(f);}])
-AC_SINGLE_CXX_CHECK([HAVE_STD_ISINF_IN_CMATH], [ac_cv_func_std_isinf_in_cmath],
-                    [std::isinf], [<cmath>],
-                    [#include <cmath>
-                     using std::isinf; int foo(float f) {return isinf(f);}])
-AC_SINGLE_CXX_CHECK([HAVE_FINITE_IN_IEEEFP_H], [ac_cv_func_finite_in_ieeefp_h],
-                    [finite], [<ieeefp.h>],
-                    [#include <ieeefp.h>
-                     int foo(float f) {return finite(f);}])
-])
-