mirror of https://gitee.com/openkylin/linux.git
194 lines
4.5 KiB
ArmAsm
194 lines
4.5 KiB
ArmAsm
/*
|
|
* Copyright (C) 2013 ARM Ltd.
|
|
* Copyright (C) 2013 Linaro.
|
|
*
|
|
* This code is based on glibc cortex strings work originally authored by Linaro
|
|
* and re-licensed under GPLv2 for the Linux kernel. The original code can
|
|
* be found @
|
|
*
|
|
* http://bazaar.launchpad.net/~linaro-toolchain-dev/cortex-strings/trunk/
|
|
* files/head:/src/aarch64/
|
|
*
|
|
* 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/>.
|
|
*/
|
|
|
|
|
|
/*
|
|
* Copy a buffer from src to dest (alignment handled by the hardware)
|
|
*
|
|
* Parameters:
|
|
* x0 - dest
|
|
* x1 - src
|
|
* x2 - n
|
|
* Returns:
|
|
* x0 - dest
|
|
*/
|
|
dstin .req x0
|
|
src .req x1
|
|
count .req x2
|
|
tmp1 .req x3
|
|
tmp1w .req w3
|
|
tmp2 .req x4
|
|
tmp2w .req w4
|
|
dst .req x6
|
|
|
|
A_l .req x7
|
|
A_h .req x8
|
|
B_l .req x9
|
|
B_h .req x10
|
|
C_l .req x11
|
|
C_h .req x12
|
|
D_l .req x13
|
|
D_h .req x14
|
|
|
|
mov dst, dstin
|
|
cmp count, #16
|
|
/*When memory length is less than 16, the accessed are not aligned.*/
|
|
b.lo .Ltiny15
|
|
|
|
neg tmp2, src
|
|
ands tmp2, tmp2, #15/* Bytes to reach alignment. */
|
|
b.eq .LSrcAligned
|
|
sub count, count, tmp2
|
|
/*
|
|
* Copy the leading memory data from src to dst in an increasing
|
|
* address order.By this way,the risk of overwriting the source
|
|
* memory data is eliminated when the distance between src and
|
|
* dst is less than 16. The memory accesses here are alignment.
|
|
*/
|
|
tbz tmp2, #0, 1f
|
|
ldrb1 tmp1w, src, #1
|
|
strb1 tmp1w, dst, #1
|
|
1:
|
|
tbz tmp2, #1, 2f
|
|
ldrh1 tmp1w, src, #2
|
|
strh1 tmp1w, dst, #2
|
|
2:
|
|
tbz tmp2, #2, 3f
|
|
ldr1 tmp1w, src, #4
|
|
str1 tmp1w, dst, #4
|
|
3:
|
|
tbz tmp2, #3, .LSrcAligned
|
|
ldr1 tmp1, src, #8
|
|
str1 tmp1, dst, #8
|
|
|
|
.LSrcAligned:
|
|
cmp count, #64
|
|
b.ge .Lcpy_over64
|
|
/*
|
|
* Deal with small copies quickly by dropping straight into the
|
|
* exit block.
|
|
*/
|
|
.Ltail63:
|
|
/*
|
|
* Copy up to 48 bytes of data. At this point we only need the
|
|
* bottom 6 bits of count to be accurate.
|
|
*/
|
|
ands tmp1, count, #0x30
|
|
b.eq .Ltiny15
|
|
cmp tmp1w, #0x20
|
|
b.eq 1f
|
|
b.lt 2f
|
|
ldp1 A_l, A_h, src, #16
|
|
stp1 A_l, A_h, dst, #16
|
|
1:
|
|
ldp1 A_l, A_h, src, #16
|
|
stp1 A_l, A_h, dst, #16
|
|
2:
|
|
ldp1 A_l, A_h, src, #16
|
|
stp1 A_l, A_h, dst, #16
|
|
.Ltiny15:
|
|
/*
|
|
* Prefer to break one ldp/stp into several load/store to access
|
|
* memory in an increasing address order,rather than to load/store 16
|
|
* bytes from (src-16) to (dst-16) and to backward the src to aligned
|
|
* address,which way is used in original cortex memcpy. If keeping
|
|
* the original memcpy process here, memmove need to satisfy the
|
|
* precondition that src address is at least 16 bytes bigger than dst
|
|
* address,otherwise some source data will be overwritten when memove
|
|
* call memcpy directly. To make memmove simpler and decouple the
|
|
* memcpy's dependency on memmove, withdrew the original process.
|
|
*/
|
|
tbz count, #3, 1f
|
|
ldr1 tmp1, src, #8
|
|
str1 tmp1, dst, #8
|
|
1:
|
|
tbz count, #2, 2f
|
|
ldr1 tmp1w, src, #4
|
|
str1 tmp1w, dst, #4
|
|
2:
|
|
tbz count, #1, 3f
|
|
ldrh1 tmp1w, src, #2
|
|
strh1 tmp1w, dst, #2
|
|
3:
|
|
tbz count, #0, .Lexitfunc
|
|
ldrb1 tmp1w, src, #1
|
|
strb1 tmp1w, dst, #1
|
|
|
|
b .Lexitfunc
|
|
|
|
.Lcpy_over64:
|
|
subs count, count, #128
|
|
b.ge .Lcpy_body_large
|
|
/*
|
|
* Less than 128 bytes to copy, so handle 64 here and then jump
|
|
* to the tail.
|
|
*/
|
|
ldp1 A_l, A_h, src, #16
|
|
stp1 A_l, A_h, dst, #16
|
|
ldp1 B_l, B_h, src, #16
|
|
ldp1 C_l, C_h, src, #16
|
|
stp1 B_l, B_h, dst, #16
|
|
stp1 C_l, C_h, dst, #16
|
|
ldp1 D_l, D_h, src, #16
|
|
stp1 D_l, D_h, dst, #16
|
|
|
|
tst count, #0x3f
|
|
b.ne .Ltail63
|
|
b .Lexitfunc
|
|
|
|
/*
|
|
* Critical loop. Start at a new cache line boundary. Assuming
|
|
* 64 bytes per line this ensures the entire loop is in one line.
|
|
*/
|
|
.p2align L1_CACHE_SHIFT
|
|
.Lcpy_body_large:
|
|
/* pre-get 64 bytes data. */
|
|
ldp1 A_l, A_h, src, #16
|
|
ldp1 B_l, B_h, src, #16
|
|
ldp1 C_l, C_h, src, #16
|
|
ldp1 D_l, D_h, src, #16
|
|
1:
|
|
/*
|
|
* interlace the load of next 64 bytes data block with store of the last
|
|
* loaded 64 bytes data.
|
|
*/
|
|
stp1 A_l, A_h, dst, #16
|
|
ldp1 A_l, A_h, src, #16
|
|
stp1 B_l, B_h, dst, #16
|
|
ldp1 B_l, B_h, src, #16
|
|
stp1 C_l, C_h, dst, #16
|
|
ldp1 C_l, C_h, src, #16
|
|
stp1 D_l, D_h, dst, #16
|
|
ldp1 D_l, D_h, src, #16
|
|
subs count, count, #64
|
|
b.ge 1b
|
|
stp1 A_l, A_h, dst, #16
|
|
stp1 B_l, B_h, dst, #16
|
|
stp1 C_l, C_h, dst, #16
|
|
stp1 D_l, D_h, dst, #16
|
|
|
|
tst count, #0x3f
|
|
b.ne .Ltail63
|
|
.Lexitfunc:
|