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

121 lines
2.7 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, lr}
lsls r3, r0, #30
beq 10f
subs r4, r1, #1
cmp r1, #0
beq 9f
lsls r5, r2, #24
lsrs r5, r5, #24
movs r3, r0
movs r6, #3
b 2f
1:
subs r1, r4, #1
cmp r4, #0
beq 9f
movs r4, r1
2:
adds r3, r3, #1
subs r1, r3, #1
strb r5, [r1]
tst r3, r6
bne 1b
3:
cmp r4, #3
bls 7f
movs r5, #255
ands r5, r2
lsls r1, r5, #8
orrs r5, r1
lsls r1, r5, #16
orrs r5, r1
cmp r4, #15
bls 5f
movs r6, r4
subs r6, r6, #16
lsrs r6, r6, #4
adds r6, r6, #1
lsls r6, r6, #4
movs r1, r3
adds r3, r3, r6
4:
str r5, [r1]
str r5, [r1, #4]
str r5, [r1, #8]
str r5, [r1, #12]
adds r1, r1, #16
cmp r3, r1
bne 4b
movs r1, #15
ands r4, r1
cmp r4, #3
bls 7f
5:
subs r6, r4, #4
lsrs r6, r6, #2
adds r6, r6, #1
lsls r6, r6, #2
movs r1, r3
adds r3, r3, r6
6:
stmia r1!, {r5}
cmp r3, r1
bne 6b
movs r1, #3
ands r4, r1
7:
cmp r4, #0
beq 9f
lsls r2, r2, #24
lsrs r2, r2, #24
adds r4, r3, r4
8:
strb r2, [r3]
adds r3, r3, #1
cmp r4, r3
bne 8b
9:
pop {r4, r5, r6}
pop {r1}
bx r1
10:
movs r3, r0
movs r4, r1
b 3b
.size __aeabi_memset, . - __aeabi_memset