--- /dev/null
+#------------------------------------------------------------------------------
+#
+# 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
+#
+#------------------------------------------------------------------------------
+
+#------------------------------------------------------------------------------
+# INTN
+# EFIAPI
+# InternalMemCompareMem (
+# IN CONST VOID *DestinationBuffer,
+# IN CONST VOID *SourceBuffer,
+# IN UINTN Length
+# );
+#------------------------------------------------------------------------------
+.global _InternalMemCompareMem;
+_InternalMemCompareMem:
+ push %rsi
+ push %rdi
+ mov %rcx, %rsi
+ mov %rdx, %rdi
+ mov %r8, %rcx
+ repe cmpsb
+ movzbq -1(%rsi), %rax
+ movzbq -1(%rdi), %rdx
+ sub %rdx, %rax
+ pop %rdi
+ pop %rsi
+ ret