1// Copyright 2015 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 "textflag.h"
8
9// See memmove Go doc for important implementation constraints.
10
11// func memmove(to, from unsafe.Pointer, n uintptr)
12TEXT runtime·memmove(SB), NOSPLIT|NOFRAME, $0-24
13	MOVV	to+0(FP), R1
14	MOVV	from+8(FP), R2
15	MOVV	n+16(FP), R3
16	BNE	R3, check
17	RET
18
19check:
20	SGTU	R1, R2, R4
21	BNE	R4, backward
22
23	ADDV	R1, R3, R6 // end pointer
24
25	// if the two pointers are not of same alignments, do byte copying
26	SUBVU	R2, R1, R4
27	AND	$7, R4
28	BNE	R4, out
29
30	// if less than 8 bytes, do byte copying
31	SGTU	$8, R3, R4
32	BNE	R4, out
33
34	// do one byte at a time until 8-aligned
35	AND	$7, R1, R5
36	BEQ	R5, words
37	MOVB	(R2), R4
38	ADDV	$1, R2
39	MOVB	R4, (R1)
40	ADDV	$1, R1
41	JMP	-6(PC)
42
43words:
44	// do 8 bytes at a time if there is room
45	ADDV	$-7, R6, R3 // R3 is end pointer-7
46
47	SGTU	R3, R1, R5
48	BEQ	R5, out
49	MOVV	(R2), R4
50	ADDV	$8, R2
51	MOVV	R4, (R1)
52	ADDV	$8, R1
53	JMP	-6(PC)
54
55out:
56	BEQ	R1, R6, done
57	MOVB	(R2), R4
58	ADDV	$1, R2
59	MOVB	R4, (R1)
60	ADDV	$1, R1
61	JMP	-5(PC)
62done:
63	RET
64
65backward:
66	ADDV	R3, R2 // from-end pointer
67	ADDV	R1, R3, R6 // to-end pointer
68
69	// if the two pointers are not of same alignments, do byte copying
70	SUBVU	R6, R2, R4
71	AND	$7, R4
72	BNE	R4, out1
73
74	// if less than 8 bytes, do byte copying
75	SGTU	$8, R3, R4
76	BNE	R4, out1
77
78	// do one byte at a time until 8-aligned
79	AND	$7, R6, R5
80	BEQ	R5, words1
81	ADDV	$-1, R2
82	MOVB	(R2), R4
83	ADDV	$-1, R6
84	MOVB	R4, (R6)
85	JMP	-6(PC)
86
87words1:
88	// do 8 bytes at a time if there is room
89	ADDV	$7, R1, R3 // R3 is start pointer+7
90
91	SGTU	R6, R3, R5
92	BEQ	R5, out1
93	ADDV	$-8, R2
94	MOVV	(R2), R4
95	ADDV	$-8, R6
96	MOVV	R4, (R6)
97	JMP	-6(PC)
98
99out1:
100	BEQ	R1, R6, done1
101	ADDV	$-1, R2
102	MOVB	(R2), R4
103	ADDV	$-1, R6
104	MOVB	R4, (R6)
105	JMP	-5(PC)
106done1:
107	RET
108