1 files changed, 7 insertions, 1 deletions
diff --git a/MdePkg/Include/X64/ProcessorBind.h b/MdePkg/Include/X64/ProcessorBind.h
index b6dd16314d..df324340d1 100644
--- a/MdePkg/Include/X64/ProcessorBind.h
+++ b/MdePkg/Include/X64/ProcessorBind.h
@@ -1,7 +1,7 @@
 /** @file
   Processor or Compiler specific defines and types x64 (Intel 64, AMD64).
 
-  Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>
   This program and the accompanying materials                          
   are licensed and made available under the terms and conditions of the BSD License         
   which accompanies this distribution.  The full text of the license may be found at        
@@ -228,6 +228,12 @@ typedef INT64   INTN;
 #define MAX_ADDRESS   0xFFFFFFFFFFFFFFFFULL
 
 ///
+/// Maximum legal x64 INTN and UINTN values.
+///
+#define MAX_INTN   ((INTN)0x7FFFFFFFFFFFFFFFULL)
+#define MAX_UINTN  ((UINTN)0xFFFFFFFFFFFFFFFFULL)
+
+///
 /// The stack alignment required for x64
 ///
 #define CPU_STACK_ALIGNMENT   16