mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-27 23:40:10 +00:00
8ecb477ea1
Remove memset-reg.h by moving register definitions into the memset implementations. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
119 lines
2.6 KiB
ArmAsm
119 lines
2.6 KiB
ArmAsm
/* Optimized memset for AmpereComputing emag processor.
|
|
Copyright (C) 2018-2024 Free Software Foundation, Inc.
|
|
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library 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
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library. If not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <sysdep.h>
|
|
|
|
/* Assumptions:
|
|
*
|
|
* ARMv8-a, AArch64, unaligned accesses
|
|
*
|
|
*/
|
|
|
|
#define dstin x0
|
|
#define val x1
|
|
#define valw w1
|
|
#define count x2
|
|
#define dst x3
|
|
#define dstend x4
|
|
|
|
ENTRY (__memset_emag)
|
|
|
|
PTR_ARG (0)
|
|
SIZE_ARG (2)
|
|
|
|
bfi valw, valw, 8, 8
|
|
bfi valw, valw, 16, 16
|
|
bfi val, val, 32, 32
|
|
|
|
add dstend, dstin, count
|
|
|
|
cmp count, 96
|
|
b.hi L(set_long)
|
|
cmp count, 16
|
|
b.hs L(set_medium)
|
|
|
|
/* Set 0..15 bytes. */
|
|
tbz count, 3, 1f
|
|
str val, [dstin]
|
|
str val, [dstend, -8]
|
|
ret
|
|
|
|
.p2align 3
|
|
1: tbz count, 2, 2f
|
|
str valw, [dstin]
|
|
str valw, [dstend, -4]
|
|
ret
|
|
2: cbz count, 3f
|
|
strb valw, [dstin]
|
|
tbz count, 1, 3f
|
|
strh valw, [dstend, -2]
|
|
3: ret
|
|
|
|
.p2align 3
|
|
/* Set 16..96 bytes. */
|
|
L(set_medium):
|
|
stp val, val, [dstin]
|
|
tbnz count, 6, L(set96)
|
|
stp val, val, [dstend, -16]
|
|
tbz count, 5, 1f
|
|
stp val, val, [dstin, 16]
|
|
stp val, val, [dstend, -32]
|
|
1: ret
|
|
|
|
.p2align 4
|
|
/* Set 64..96 bytes. Write 64 bytes from the start and
|
|
32 bytes from the end. */
|
|
L(set96):
|
|
stp val, val, [dstin, 16]
|
|
stp val, val, [dstin, 32]
|
|
stp val, val, [dstin, 48]
|
|
stp val, val, [dstend, -32]
|
|
stp val, val, [dstend, -16]
|
|
ret
|
|
|
|
.p2align 4
|
|
L(set_long):
|
|
stp val, val, [dstin]
|
|
bic dst, dstin, 15
|
|
/* Small-size or non-zero memset does not use DC ZVA. */
|
|
sub count, dstend, dst
|
|
|
|
/*
|
|
* Adjust count and bias for loop. By subtracting extra 1 from count,
|
|
* it is easy to use tbz instruction to check whether loop tailing
|
|
* count is less than 33 bytes, so as to bypass 2 unnecessary stps.
|
|
*/
|
|
sub count, count, 64+16+1
|
|
|
|
1: stp val, val, [dst, 16]
|
|
stp val, val, [dst, 32]
|
|
stp val, val, [dst, 48]
|
|
stp val, val, [dst, 64]!
|
|
subs count, count, 64
|
|
b.hs 1b
|
|
|
|
tbz count, 5, 1f /* Remaining count is less than 33 bytes? */
|
|
stp val, val, [dst, 16]
|
|
stp val, val, [dst, 32]
|
|
1: stp val, val, [dstend, -32]
|
|
stp val, val, [dstend, -16]
|
|
ret
|
|
|
|
END (__memset_emag)
|