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

47 lines
932 B
NASM

//------------------------------------------------------------------------------
//
// Copyright (c) 2011-2014, ARM Limited. All rights reserved.
//
// SPDX-License-Identifier: BSD-2-Clause-Patent
//
//------------------------------------------------------------------------------
INCLUDE AsmMacroExport.inc
;
;VOID
;EFIAPI
;__aeabi_memmove (
; IN VOID *Destination,
; IN CONST VOID *Source,
; IN UINT32 Size
; );
;
RVCT_ASM_EXPORT __aeabi_memmove
CMP r2, #0
BXEQ lr
CMP r0, r1
BXEQ lr
BHI memmove_backward
memmove_forward
LDRB r3, [r1], #1
STRB r3, [r0], #1
SUBS r2, r2, #1
BNE memmove_forward
BX lr
memmove_backward
add r0, r2
add r1, r2
memmove_backward_loop
LDRB r3, [r1, #-1]!
STRB r3, [r0, #-1]!
SUBS r2, r2, #1
BNE memmove_backward_loop
BX lr
END