Add BaseMemoryLib optimized for PEI

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@4035 6f19259b-4bc3-4df7-8a09-765794883524

MdePkg/Library/BaseMemoryLibOptPei/Ia32/ZeroMem.S

@@ -0,0 +1,49 @@
+#------------------------------------------------------------------------------
+#
+# 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:
+#
+#   ZeroMem.Asm
+#
+# Abstract:
+#
+#   ZeroMem function
+#
+# Notes:
+#
+#------------------------------------------------------------------------------
+
+.globl _InternalMemZeroMem
+
+#------------------------------------------------------------------------------
+#  VOID *
+#  InternalMemZeroMem (
+#    IN VOID   *Buffer,
+#    IN UINTN  Count
+#    );
+#------------------------------------------------------------------------------
+_InternalMemZeroMem:
+    push    %edi
+    xorl    %eax,%eax
+    movl    8(%esp),%edi
+    movl    12(%esp),%ecx
+    movl    %ecx,%edx
+    shrl    $2,%ecx
+    andl    $3,%edx
+    pushl   %edi
+    rep
+    stosl
+    movl    %edx,%ecx
+    rep
+    stosb
+    popl    %eax
+    pop     %edi
+    ret