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

41 lines
889 B
ArmAsm

#------------------------------------------------------------------------------
#
# Copyright (c) 2011-2014, ARM Limited. All rights reserved.
#
# SPDX-License-Identifier: BSD-2-Clause-Patent
#
#------------------------------------------------------------------------------
#include <AsmMacroIoLib.h>
# VOID
# EFIAPI
# memmove (
# IN VOID *Destination,
# IN CONST VOID *Source,
# IN UINT32 Size
# );
ASM_FUNC(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
BXEQ lr
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 lr
B memmove_backward_loop