1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
|
/* Optimized memset for Fujitsu A64FX processor.
Copyright (C) 2021 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>
#include <sysdeps/aarch64/memset-reg.h>
/* Assumptions:
*
* ARMv8.2-a, AArch64, unaligned accesses, sve
*
*/
#define L1_SIZE (64*1024) // L1 64KB
#define L2_SIZE (8*1024*1024) // L2 8MB
#define CACHE_LINE_SIZE 256
#define PF_DIST_L1 (CACHE_LINE_SIZE * 16) // Prefetch distance L1
#define vector_length x9
#if HAVE_AARCH64_SVE_ASM
# if IS_IN (libc)
# define MEMSET __memset_a64fx
.arch armv8.2-a+sve
.macro st1b_unroll first=0, last=7
st1b z0.b, p0, [dst, \first, mul vl]
.if \last-\first
st1b_unroll "(\first+1)", \last
.endif
.endm
#undef BTI_C
#define BTI_C
ENTRY (MEMSET)
PTR_ARG (0)
SIZE_ARG (2)
cntb vector_length
dup z0.b, valw
whilelo p0.b, vector_length, count
b.last 1f
whilelo p1.b, xzr, count
st1b z0.b, p1, [dstin, 0, mul vl]
st1b z0.b, p0, [dstin, 1, mul vl]
ret
// count >= vector_length * 2
1: cmp count, vector_length, lsl 2
add dstend, dstin, count
b.hi 1f
st1b z0.b, p0, [dstin, 0, mul vl]
st1b z0.b, p0, [dstin, 1, mul vl]
st1b z0.b, p0, [dstend, -2, mul vl]
st1b z0.b, p0, [dstend, -1, mul vl]
ret
// count > vector_length * 4
1: lsl tmp1, vector_length, 3
cmp count, tmp1
b.hi L(vl_agnostic)
st1b z0.b, p0, [dstin, 0, mul vl]
st1b z0.b, p0, [dstin, 1, mul vl]
st1b z0.b, p0, [dstin, 2, mul vl]
st1b z0.b, p0, [dstin, 3, mul vl]
st1b z0.b, p0, [dstend, -4, mul vl]
st1b z0.b, p0, [dstend, -3, mul vl]
st1b z0.b, p0, [dstend, -2, mul vl]
st1b z0.b, p0, [dstend, -1, mul vl]
ret
.p2align 4
L(vl_agnostic): // VL Agnostic
mov dst, dstin
cmp count, L1_SIZE
b.hi L(L1_prefetch)
// count >= 8 * vector_length
L(unroll8):
sub count, count, tmp1
.p2align 4
1: st1b_unroll 0, 7
add dst, dst, tmp1
subs count, count, tmp1
b.hi 1b
add count, count, tmp1
L(last):
cmp count, vector_length, lsl 1
b.ls 2f
add tmp2, vector_length, vector_length, lsl 2
cmp count, tmp2
b.ls 5f
st1b z0.b, p0, [dstend, -8, mul vl]
st1b z0.b, p0, [dstend, -7, mul vl]
st1b z0.b, p0, [dstend, -6, mul vl]
5: st1b z0.b, p0, [dstend, -5, mul vl]
st1b z0.b, p0, [dstend, -4, mul vl]
st1b z0.b, p0, [dstend, -3, mul vl]
2: st1b z0.b, p0, [dstend, -2, mul vl]
st1b z0.b, p0, [dstend, -1, mul vl]
ret
// count >= L1_SIZE
.p2align 3
L(L1_prefetch):
cmp count, L2_SIZE
b.hs L(L2)
cmp vector_length, 64
b.ne L(unroll8)
1: st1b_unroll 0, 3
prfm pstl1keep, [dst, PF_DIST_L1]
st1b_unroll 4, 7
prfm pstl1keep, [dst, PF_DIST_L1 + CACHE_LINE_SIZE]
add dst, dst, CACHE_LINE_SIZE * 2
sub count, count, CACHE_LINE_SIZE * 2
cmp count, PF_DIST_L1
b.hs 1b
b L(unroll8)
// count >= L2_SIZE
.p2align 3
L(L2):
tst valw, 255
b.ne L(unroll8)
// align dst to CACHE_LINE_SIZE byte boundary
and tmp2, dst, CACHE_LINE_SIZE - 1
st1b z0.b, p0, [dst, 0, mul vl]
st1b z0.b, p0, [dst, 1, mul vl]
st1b z0.b, p0, [dst, 2, mul vl]
st1b z0.b, p0, [dst, 3, mul vl]
sub dst, dst, tmp2
add count, count, tmp2
// clear cachelines using DC ZVA
sub count, count, CACHE_LINE_SIZE * 2
.p2align 4
1: add dst, dst, CACHE_LINE_SIZE
dc zva, dst
subs count, count, CACHE_LINE_SIZE
b.hi 1b
add count, count, CACHE_LINE_SIZE
b L(last)
END (MEMSET)
libc_hidden_builtin_def (MEMSET)
#endif /* IS_IN (libc) */
#endif /* HAVE_AARCH64_SVE_ASM */
|
