diff --git a/llvm/lib/Support/IsInf.cpp b/llvm/lib/Support/IsInf.cpp
new file mode 100644
index 000000000000..4142b911e2cb
--- /dev/null
+++ b/llvm/lib/Support/IsInf.cpp
@@ -0,0 +1,31 @@
+//===-- IsInf.cpp ---------------------------------------------------------===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// Platform-independent wrapper around C99 isinf(). 
+//
+//===----------------------------------------------------------------------===//
+
+#include "Config/config.h"
+#if HAVE_ISINF_IN_MATH_H
+# include <math.h>
+#elif HAVE_ISINF_IN_CMATH
+# include <cmath>
+#elif HAVE_STD_ISINF_IN_CMATH
+# include <cmath>
+using std::isinf;
+#else
+# error "Don't know how to get isinf()"
+#endif
+
+namespace llvm {
+
+int IsInf (float f)  { return isinf (f); }
+int IsInf (double d) { return isinf (d); }
+
+}; // end namespace llvm;