rockbox/firmware/asm/arm/memset16.S
Solomon Peachy 8c86fb6da0 arm: Use -masm-syntax-unified when compiling with gcc8 or newer
Annoyingly, this makes all of the '.S' files we compile get treated as
divided syntax, so we need to make the syntax in them explicit.

Change-Id: I56a3916b7b24c84a1214a5d6bc4ed4d651f002cf
2024-05-08 21:45:42 -04:00

84 lines
2.5 KiB
ArmAsm

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2006 by Thom Johansen
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "config.h"
.syntax unified
.section .icode,"ax",%progbits
.align 2
/* The following code is based on code from the Linux kernel version 2.6.15.3,
* linux/arch/arm/lib/memset.S
*
* Copyright (C) 1995-2000 Russell King
*/
.global memset16
.type memset16,%function
memset16:
tst r0, #2 @ unaligned?
cmpne r2, #0
strhne r1, [r0], #2 @ store one halfword to align
subne r2, r2, #1
/*
* we know that the pointer in r0 is aligned to a word boundary.
*/
orr r1, r1, r1, lsl #16
mov r3, r1
cmp r2, #8
blt 4f
/*
* We need an extra register for this loop - save the return address and
* use the LR
*/
str lr, [sp, #-4]!
mov ip, r1
mov lr, r1
2: subs r2, r2, #32
stmiage r0!, {r1, r3, ip, lr} @ 64 bytes at a time.
stmiage r0!, {r1, r3, ip, lr}
stmiage r0!, {r1, r3, ip, lr}
stmiage r0!, {r1, r3, ip, lr}
bgt 2b
ldrpc cond=eq @ Now <64 bytes to go.
/*
* No need to correct the count; we're only testing bits from now on
*/
tst r2, #16
stmiane r0!, {r1, r3, ip, lr}
stmiane r0!, {r1, r3, ip, lr}
tst r2, #8
stmiane r0!, {r1, r3, ip, lr}
ldr lr, [sp], #4
4: tst r2, #4
stmiane r0!, {r1, r3}
tst r2, #2
strne r1, [r0], #4
tst r2, #1
strhne r1, [r0], #2
bx lr
.end:
.size memset16,.end-memset16