Text file
src/runtime/memclr_s390x.s
Documentation: runtime
1// Copyright 2016 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5#include "textflag.h"
6
7// See memclrNoHeapPointers Go doc for important implementation constraints.
8
9// func memclrNoHeapPointers(ptr unsafe.Pointer, n uintptr)
10TEXT runtime·memclrNoHeapPointers<ABIInternal>(SB),NOSPLIT|NOFRAME,$0-16
11#ifndef GOEXPERIMENT_regabiargs
12 MOVD ptr+0(FP), R4
13 MOVD n+8(FP), R5
14#else
15 MOVD R2, R4
16 MOVD R3, R5
17#endif
18 CMPBGE R5, $32, clearge32
19
20start:
21 CMPBLE R5, $3, clear0to3
22 CMPBLE R5, $7, clear4to7
23 CMPBLE R5, $11, clear8to11
24 CMPBLE R5, $15, clear12to15
25 MOVD $0, 0(R4)
26 MOVD $0, 8(R4)
27 ADD $16, R4
28 SUB $16, R5
29 BR start
30
31clear0to3:
32 CMPBEQ R5, $0, done
33 CMPBNE R5, $1, clear2
34 MOVB $0, 0(R4)
35 RET
36clear2:
37 CMPBNE R5, $2, clear3
38 MOVH $0, 0(R4)
39 RET
40clear3:
41 MOVH $0, 0(R4)
42 MOVB $0, 2(R4)
43 RET
44
45clear4to7:
46 CMPBNE R5, $4, clear5
47 MOVW $0, 0(R4)
48 RET
49clear5:
50 CMPBNE R5, $5, clear6
51 MOVW $0, 0(R4)
52 MOVB $0, 4(R4)
53 RET
54clear6:
55 CMPBNE R5, $6, clear7
56 MOVW $0, 0(R4)
57 MOVH $0, 4(R4)
58 RET
59clear7:
60 MOVW $0, 0(R4)
61 MOVH $0, 4(R4)
62 MOVB $0, 6(R4)
63 RET
64
65clear8to11:
66 CMPBNE R5, $8, clear9
67 MOVD $0, 0(R4)
68 RET
69clear9:
70 CMPBNE R5, $9, clear10
71 MOVD $0, 0(R4)
72 MOVB $0, 8(R4)
73 RET
74clear10:
75 CMPBNE R5, $10, clear11
76 MOVD $0, 0(R4)
77 MOVH $0, 8(R4)
78 RET
79clear11:
80 MOVD $0, 0(R4)
81 MOVH $0, 8(R4)
82 MOVB $0, 10(R4)
83 RET
84
85clear12to15:
86 CMPBNE R5, $12, clear13
87 MOVD $0, 0(R4)
88 MOVW $0, 8(R4)
89 RET
90clear13:
91 CMPBNE R5, $13, clear14
92 MOVD $0, 0(R4)
93 MOVW $0, 8(R4)
94 MOVB $0, 12(R4)
95 RET
96clear14:
97 CMPBNE R5, $14, clear15
98 MOVD $0, 0(R4)
99 MOVW $0, 8(R4)
100 MOVH $0, 12(R4)
101 RET
102clear15:
103 MOVD $0, 0(R4)
104 MOVW $0, 8(R4)
105 MOVH $0, 12(R4)
106 MOVB $0, 14(R4)
107 RET
108
109clearge32:
110 CMP R5, $4096
111 BLT clear256Bto4KB
112
113// For size >= 4KB, XC is loop unrolled 16 times (4KB = 256B * 16)
114clearge4KB:
115 XC $256, 0(R4), 0(R4)
116 XC $256, 256(R4), 256(R4)
117 XC $256, 512(R4), 512(R4)
118 XC $256, 768(R4), 768(R4)
119 XC $256, 1024(R4), 1024(R4)
120 XC $256, 1280(R4), 1280(R4)
121 XC $256, 1536(R4), 1536(R4)
122 XC $256, 1792(R4), 1792(R4)
123 XC $256, 2048(R4), 2048(R4)
124 XC $256, 2304(R4), 2304(R4)
125 XC $256, 2560(R4), 2560(R4)
126 XC $256, 2816(R4), 2816(R4)
127 XC $256, 3072(R4), 3072(R4)
128 XC $256, 3328(R4), 3328(R4)
129 XC $256, 3584(R4), 3584(R4)
130 XC $256, 3840(R4), 3840(R4)
131 ADD $4096, R4
132 ADD $-4096, R5
133 CMP R5, $4096
134 BGE clearge4KB
135
136clear256Bto4KB:
137 CMP R5, $256
138 BLT clear32to255
139 XC $256, 0(R4), 0(R4)
140 ADD $256, R4
141 ADD $-256, R5
142 BR clear256Bto4KB
143
144clear32to255:
145 CMPBEQ R5, $0, done
146 CMPBLT R5, $32, start
147 CMPBEQ R5, $32, clear32
148 CMPBLE R5, $64, clear33to64
149 CMP R5, $128
150 BLE clear65to128
151 CMP R5, $255
152 BLE clear129to255
153
154clear32:
155 VZERO V1
156 VST V1, 0(R4)
157 VST V1, 16(R4)
158 RET
159
160clear33to64:
161 VZERO V1
162 VST V1, 0(R4)
163 VST V1, 16(R4)
164 ADD $-32, R5
165 VST V1, 0(R4)(R5)
166 VST V1, 16(R4)(R5)
167 RET
168
169clear65to128:
170 VZERO V1
171 VST V1, 0(R4)
172 VST V1, 16(R4)
173 VST V1, 32(R4)
174 VST V1, 48(R4)
175 ADD $-64, R5
176 VST V1, 0(R4)(R5)
177 VST V1, 16(R4)(R5)
178 VST V1, 32(R4)(R5)
179 VST V1, 48(R4)(R5)
180 RET
181
182clear129to255:
183 VZERO V1
184 VST V1, 0(R4)
185 VST V1, 16(R4)
186 VST V1, 32(R4)
187 VST V1, 48(R4)
188 VST V1, 64(R4)
189 VST V1, 80(R4)
190 VST V1, 96(R4)
191 VST V1, 112(R4)
192 ADD $-128, R5
193 VST V1, 0(R4)(R5)
194 VST V1, 16(R4)(R5)
195 VST V1, 32(R4)(R5)
196 VST V1, 48(R4)(R5)
197 VST V1, 64(R4)(R5)
198 VST V1, 80(R4)(R5)
199 VST V1, 96(R4)(R5)
200 VST V1, 112(R4)(R5)
201 RET
202
203done:
204 RET
205
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