audk/MdePkg/Library/BaseMemoryLibOptDxe/X64/CompareMem.S

#
# ConvertAsm.py: Automatically generated from CompareMem.asm
#
#------------------------------------------------------------------------------
#
# 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:
#
#   CompareMem.S
#
# Abstract:
#
#   CompareMem function
#
# Notes:
#
#   The following BaseMemoryLib instances contain the same copy of this file:
#
#       BaseMemoryLibRepStr
#       BaseMemoryLibMmx
#       BaseMemoryLibSse2
#       BaseMemoryLibOptDxe
#       BaseMemoryLibOptPei
#
#------------------------------------------------------------------------------


#------------------------------------------------------------------------------
# INTN
# EFIAPI
# InternalMemCompareMem (
#   IN      CONST VOID                *DestinationBuffer,
#   IN      CONST VOID                *SourceBuffer,
#   IN      UINTN                     Length
#   );
#------------------------------------------------------------------------------
.intel_syntax noprefix
.globl ASM_PFX(InternalMemCompareMem)
ASM_PFX(InternalMemCompareMem):
    push    rsi
    push    rdi
    mov     rsi, rcx
    mov     rdi, rdx
    mov     rcx, r8
    repe    cmpsb
    movzx   rax, byte ptr [rsi - 1]
    movzx   rdx, byte ptr [rdi - 1]
    sub     rax, rdx
    pop     rdi
    pop     rsi
    ret