newlib-cygwin/newlib/libc/machine/arm/aeabi_memset-thumb2.S

108 lines
2.5 KiB
ArmAsm

/*
* Copyright (c) 2015 ARM Ltd
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the company may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
.thumb
.syntax unified
.global __aeabi_memset
.type __aeabi_memset, %function
ASM_ALIAS __aeabi_memset4 __aeabi_memset
ASM_ALIAS __aeabi_memset8 __aeabi_memset
__aeabi_memset:
push {r4, r5, r6}
lsls r4, r0, #30
beq 10f
subs r4, r1, #1
cmp r1, #0
beq 9f
uxtb r5, r2
mov r3, r0
b 2f
1:
subs r1, r4, #1
cbz r4, 9f
mov r4, r1
2:
strb r5, [r3], #1
lsls r1, r3, #30
bne 1b
3:
cmp r4, #3
bls 7f
uxtb r5, r2
orr r5, r5, r5, lsl #8
cmp r4, #15
orr r5, r5, r5, lsl #16
bls 5f
mov r6, r4
add r1, r3, #16
4:
subs r6, r6, #16
cmp r6, #15
str r5, [r1, #-16]
str r5, [r1, #-12]
str r5, [r1, #-8]
str r5, [r1, #-4]
add r1, r1, #16
bhi 4b
sub r1, r4, #16
bic r1, r1, #15
and r4, r4, #15
adds r1, r1, #16
cmp r4, #3
add r3, r3, r1
bls 7f
5:
mov r6, r3
mov r1, r4
6:
subs r1, r1, #4
cmp r1, #3
str r5, [r6], #4
bhi 6b
subs r1, r4, #4
bic r1, r1, #3
adds r1, r1, #4
add r3, r3, r1
and r4, r4, #3
7:
cbz r4, 9f
uxtb r2, r2
add r4, r4, r3
8:
strb r2, [r3], #1
cmp r3, r4
bne 8b
9:
pop {r4, r5, r6}
bx lr
10:
mov r4, r1
mov r3, r0
b 3b
.size __aeabi_memset, . - __aeabi_memset