Split out Synchronization Library from Base Library

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@7377 6f19259b-4bc3-4df7-8a09-765794883524

MdePkg/Library/BaseSynchronizationLib/X64/InterlockedDecrement.S

@@ -0,0 +1,36 @@
+#------------------------------------------------------------------------------
+#
+# Copyright (c) 2006 - 2008, Intel Corporation
+# All rights reserved. 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
+# http://opensource.org/licenses/bsd-license.php
+#
+# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+#
+# Module Name:
+#
+#   InterlockedDecrement.S
+#
+# Abstract:
+#
+#   InterlockedDecrement function
+#
+# Notes:
+#
+#------------------------------------------------------------------------------
+
+
+#------------------------------------------------------------------------------
+# UINT32
+# EFIAPI
+# InterlockedDecrement (
+#   IN      UINT32                    *Value
+#   );
+#------------------------------------------------------------------------------
+.global ASM_PFX(InternalSyncDecrement)
+ASM_PFX(InternalSyncDecrement):
+    lock    decl (%rcx)
+    mov     (%rcx), %eax
+    ret