audk/ArmPkg/Library/CompilerIntrinsicsLib/Arm/memmove.asm

55 lines
1.3 KiB
NASM
Executable File

//------------------------------------------------------------------------------
//
// Copyright (c) 2011, ARM Limited. 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.
//
//------------------------------------------------------------------------------
EXPORT __aeabi_memmove
AREA Memmove, CODE, READONLY
;
;VOID
;EFIAPI
;__aeabi_memmove (
; IN VOID *Destination,
; IN CONST VOID *Source,
; IN UINT32 Size
; );
;
__aeabi_memmove
CMP r2, #0
BXEQ r14
CMP r0, r1
BXEQ r14
BHI memmove_backward
BLS memmove_forward
memmove_forward
LDRB r3, [r1], #1
STRB r3, [r0], #1
SUBS r2, r2, #1
BXEQ r14
B memmove_forward
memmove_backward
add r0, r2
add r1, r2
memmove_backward_loop
LDRB r3, [r1], #-1
STRB r3, [r0], #-1
SUBS r2, r2, #-1
BXEQ r14
B memmove_backward_loop
END