coreboot-kgpe-d16/src/arch/arm64/memmove.S
Furquan Shaikh 464f5ca6d6 Revert "arm64: remove assembly code string functions"
This reverts commit 00263d0d8e
to reintroduce optimized string handling functions.

BUG=chrome-os-partner:41185
BRANCH=None
TEST=Compiles successfully and boots to kernel prompt on Smaug

Change-Id: I47f8d8afa5c9ff3fca67d4d0f393336fef03402b
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: eeb38afea828a2727d815e4fb5762cfdd09a2b3a
Original-Change-Id: Id053cbcea8b5e7ae29bdd6bb8b6f5e5011c42b00
Original-Signed-off-by: Furquan Shaikh <furquan@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/275865
Original-Trybot-Ready: Furquan Shaikh <furquan@chromium.org>
Original-Tested-by: Furquan Shaikh <furquan@chromium.org>
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Commit-Queue: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: http://review.coreboot.org/10564
Tested-by: build bot (Jenkins)
Reviewed-by: Marc Jones <marc.jones@se-eng.com>
2015-06-23 08:20:11 +02:00

55 lines
1.3 KiB
ArmAsm

/*
* Copyright (C) 2013 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <arch/asm.h>
/*
* Move a buffer from src to test (alignment handled by the hardware).
* If dest <= src, call memcpy, otherwise copy in reverse order.
*
* Parameters:
* x0 - dest
* x1 - src
* x2 - n
* Returns:
* x0 - dest
*/
ENTRY(memmove)
cmp x0, x1
b.ls memcpy
add x4, x0, x2
add x1, x1, x2
subs x2, x2, #8
b.mi 2f
1: ldr x3, [x1, #-8]!
subs x2, x2, #8
str x3, [x4, #-8]!
b.pl 1b
2: adds x2, x2, #4
b.mi 3f
ldr w3, [x1, #-4]!
sub x2, x2, #4
str w3, [x4, #-4]!
3: adds x2, x2, #2
b.mi 4f
ldrh w3, [x1, #-2]!
sub x2, x2, #2
strh w3, [x4, #-2]!
4: adds x2, x2, #1
b.mi 5f
ldrb w3, [x1, #-1]
strb w3, [x4, #-1]
5: ret
ENDPROC(memmove)