nuttx/libs/libc/machine/risc-v/gnu/arch_memset.S
zhangyuan21 f8f29c8147 libc: add risc-v libc function
Porting memory and string optimize functions from newlib and bionic

Signed-off-by: zhangyuan21 <zhangyuan21@xiaomi.com>
2023-01-10 11:31:26 +08:00

107 lines
1.9 KiB
ArmAsm

/****************************************************************************
* libs/libc/machine/risc-v/gnu/arch_memset.S
*
* Copyright (c) 2017 SiFive Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the FreeBSD License. This program is distributed in the hope that
* it will be useful, but WITHOUT ANY WARRANTY expressed or implied,
* including the implied warranties of MERCHANTABILITY or FITNESS FOR
* A PARTICULAR PURPOSE. A copy of this license is available at
* http://www.opensource.org/licenses.
*
****************************************************************************/
.text
.global memset
.type memset, @function
memset:
li t1, 15
move a4, a0
bleu a2, t1, .Ltiny
and a5, a4, 15
bnez a5, .Lmisaligned
.Laligned:
bnez a1, .Lwordify
.Lwordified:
and a3, a2, ~15
and a2, a2, 15
add a3, a3, a4
#if __riscv_xlen == 64
1:
sd a1, 0(a4)
sd a1, 8(a4)
#else
1:
sw a1, 0(a4)
sw a1, 4(a4)
sw a1, 8(a4)
sw a1, 12(a4)
#endif
add a4, a4, 16
bltu a4, a3, 1b
bnez a2, .Ltiny
ret
.Ltiny:
sub a3, t1, a2
sll a3, a3, 2
1:
auipc t0, %pcrel_hi(.Ltable)
add a3, a3, t0
.option push
.option norvc
.Ltable_misaligned:
jr a3, %pcrel_lo(1b)
.Ltable:
sb a1,14(a4)
sb a1,13(a4)
sb a1,12(a4)
sb a1,11(a4)
sb a1,10(a4)
sb a1, 9(a4)
sb a1, 8(a4)
sb a1, 7(a4)
sb a1, 6(a4)
sb a1, 5(a4)
sb a1, 4(a4)
sb a1, 3(a4)
sb a1, 2(a4)
sb a1, 1(a4)
sb a1, 0(a4)
.option pop
ret
.Lwordify:
and a1, a1, 0xFF
sll a3, a1, 8
or a1, a1, a3
sll a3, a1, 16
or a1, a1, a3
#if __riscv_xlen == 64
sll a3, a1, 32
or a1, a1, a3
#endif
j .Lwordified
.Lmisaligned:
sll a3, a5, 2
1:
auipc t0, %pcrel_hi(.Ltable_misaligned)
add a3, a3, t0
mv t0, ra
jalr a3, %pcrel_lo(1b)
mv ra, t0
add a5, a5, -16
sub a4, a4, a5
add a2, a2, a5
bleu a2, t1, .Ltiny
j .Laligned
.size memset, .-memset