1 // Copyright 2020 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 // func xorBytesARM64(dst, a, b *byte, n int)
8 TEXT ·xorBytesARM64(SB), NOSPLIT|NOFRAME, $0
9 MOVD dst+0(FP), R0
10 MOVD a+8(FP), R1
11 MOVD b+16(FP), R2
12 MOVD n+24(FP), R3
13 CMP $64, R3
14 BLT tail
15 loop_64:
16 VLD1.P 64(R1), [V0.B16, V1.B16, V2.B16, V3.B16]
17 VLD1.P 64(R2), [V4.B16, V5.B16, V6.B16, V7.B16]
18 VEOR V0.B16, V4.B16, V4.B16
19 VEOR V1.B16, V5.B16, V5.B16
20 VEOR V2.B16, V6.B16, V6.B16
21 VEOR V3.B16, V7.B16, V7.B16
22 VST1.P [V4.B16, V5.B16, V6.B16, V7.B16], 64(R0)
23 SUBS $64, R3
24 CMP $64, R3
25 BGE loop_64
26 tail:
27 // quick end
28 CBZ R3, end
29 TBZ $5, R3, less_than32
30 VLD1.P 32(R1), [V0.B16, V1.B16]
31 VLD1.P 32(R2), [V2.B16, V3.B16]
32 VEOR V0.B16, V2.B16, V2.B16
33 VEOR V1.B16, V3.B16, V3.B16
34 VST1.P [V2.B16, V3.B16], 32(R0)
35 less_than32:
36 TBZ $4, R3, less_than16
37 LDP.P 16(R1), (R11, R12)
38 LDP.P 16(R2), (R13, R14)
39 EOR R11, R13, R13
40 EOR R12, R14, R14
41 STP.P (R13, R14), 16(R0)
42 less_than16:
43 TBZ $3, R3, less_than8
44 MOVD.P 8(R1), R11
45 MOVD.P 8(R2), R12
46 EOR R11, R12, R12
47 MOVD.P R12, 8(R0)
48 less_than8:
49 TBZ $2, R3, less_than4
50 MOVWU.P 4(R1), R13
51 MOVWU.P 4(R2), R14
52 EORW R13, R14, R14
53 MOVWU.P R14, 4(R0)
54 less_than4:
55 TBZ $1, R3, less_than2
56 MOVHU.P 2(R1), R15
57 MOVHU.P 2(R2), R16
58 EORW R15, R16, R16
59 MOVHU.P R16, 2(R0)
60 less_than2:
61 TBZ $0, R3, end
62 MOVBU (R1), R17
63 MOVBU (R2), R19
64 EORW R17, R19, R19
65 MOVBU R19, (R0)
66 end:
67 RET
68
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