Add BaseMemoryLib optimized for DXE

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@4036 6f19259b-4bc3-4df7-8a09-765794883524

MdePkg/Library/BaseMemoryLibOptDxe/Ia32/CompareMem.S

@@ -0,0 +1,53 @@
+#------------------------------------------------------------------------------
+#
+# Copyright (c) 2006, 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:
+#
+#   CompareMem.Asm
+#
+# Abstract:
+#
+#   CompareMem function
+#
+# Notes:
+#
+#   The following BaseMemoryLib instances share the same version of this file:
+#
+#       BaseMemoryLibRepStr
+#       BaseMemoryLibMmx
+#       BaseMemoryLibSse2
+#
+#------------------------------------------------------------------------------
+
+.globl _InternalMemCompareMem
+
+#------------------------------------------------------------------------------
+# INTN
+# EFIAPI
+# InternalMemCompareMem (
+#   IN      CONST VOID                *DestinationBuffer,
+#   IN      CONST VOID                *SourceBuffer,
+#   IN      UINTN                     Length
+#   );
+#------------------------------------------------------------------------------
+_InternalMemCompareMem:
+    push    %esi
+    push    %edi
+    movl    12(%esp), %esi
+    movl    16(%esp), %edi
+    movl    20(%esp), %ecx
+    repe    cmpsb
+    movzbl  -1(%esi), %eax
+    movzbl  -1(%edi), %edx
+    subl    %edx, %eax
+    pop     %edi
+    pop     %esi
+    ret