1// Copyright 2019 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//go:build mips64 || mips64le
6
7#include "go_asm.h"
8#include "textflag.h"
9
10TEXT ·Compare(SB),NOSPLIT,$0-56
11 MOVV a_base+0(FP), R3
12 MOVV b_base+24(FP), R4
13 MOVV a_len+8(FP), R1
14 MOVV b_len+32(FP), R2
15 MOVV $ret+48(FP), R9
16 JMP cmpbody<>(SB)
17
18TEXT runtime·cmpstring(SB),NOSPLIT,$0-40
19 MOVV a_base+0(FP), R3
20 MOVV b_base+16(FP), R4
21 MOVV a_len+8(FP), R1
22 MOVV b_len+24(FP), R2
23 MOVV $ret+32(FP), R9
24 JMP cmpbody<>(SB)
25
26// On entry:
27// R1 length of a
28// R2 length of b
29// R3 points to the start of a
30// R4 points to the start of b
31// R9 points to the return value (-1/0/1)
32TEXT cmpbody<>(SB),NOSPLIT|NOFRAME,$0
33 BEQ R3, R4, samebytes // same start of a and b
34
35 SGTU R1, R2, R7
36 BNE R0, R7, r2_lt_r1
37 MOVV R1, R10
38 JMP entry
39r2_lt_r1:
40 MOVV R2, R10 // R10 is min(R1, R2)
41entry:
42 ADDV R3, R10, R8 // R3 start of a, R8 end of a
43 BEQ R3, R8, samebytes // length is 0
44
45 SRLV $4, R10 // R10 is number of chunks
46 BEQ R0, R10, byte_loop
47
48 // make sure both a and b are aligned.
49 OR R3, R4, R11
50 AND $7, R11
51 BNE R0, R11, byte_loop
52
53chunk16_loop:
54 BEQ R0, R10, byte_loop
55 MOVV (R3), R6
56 MOVV (R4), R7
57 BNE R6, R7, byte_loop
58 MOVV 8(R3), R13
59 MOVV 8(R4), R14
60 ADDV $16, R3
61 ADDV $16, R4
62 SUBVU $1, R10
63 BEQ R13, R14, chunk16_loop
64 SUBV $8, R3
65 SUBV $8, R4
66
67byte_loop:
68 BEQ R3, R8, samebytes
69 MOVBU (R3), R6
70 ADDVU $1, R3
71 MOVBU (R4), R7
72 ADDVU $1, R4
73 BEQ R6, R7, byte_loop
74
75byte_cmp:
76 SGTU R6, R7, R8 // R8 = 1 if (R6 > R7)
77 BNE R0, R8, ret
78 MOVV $-1, R8
79 JMP ret
80
81samebytes:
82 SGTU R1, R2, R6
83 SGTU R2, R1, R7
84 SUBV R7, R6, R8
85
86ret:
87 MOVV R8, (R9)
88 RET
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