audk/MdePkg/Library/BaseMemoryLibSse2/X64/CompareMem.nasm

53 lines
1.3 KiB
NASM

;------------------------------------------------------------------------------
;
; Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
; SPDX-License-Identifier: BSD-2-Clause-Patent
;
; Module Name:
;
; CompareMem.Asm
;
; Abstract:
;
; CompareMem function
;
; Notes:
;
; The following BaseMemoryLib instances contain the same copy of this file:
;
; BaseMemoryLibRepStr
; BaseMemoryLibMmx
; BaseMemoryLibSse2
; BaseMemoryLibOptDxe
; BaseMemoryLibOptPei
;
;------------------------------------------------------------------------------
DEFAULT REL
SECTION .text
;------------------------------------------------------------------------------
; INTN
; EFIAPI
; InternalMemCompareMem (
; IN CONST VOID *DestinationBuffer,
; IN CONST VOID *SourceBuffer,
; IN UINTN Length
; );
;------------------------------------------------------------------------------
global ASM_PFX(InternalMemCompareMem)
ASM_PFX(InternalMemCompareMem):
push rsi
push rdi
mov rsi, rcx
mov rdi, rdx
mov rcx, r8
repe cmpsb
movzx rax, byte [rsi - 1]
movzx rdx, byte [rdi - 1]
sub rax, rdx
pop rdi
pop rsi
ret