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
167
168
169
|
TEXT memmove(SB), $0
JMP move
TEXT memcpy(SB), $0
move:
/*
* performance:
* (tba)
*/
MOVW R7, s1+0(FP)
MOVW n+8(FP), R9 /* R9 is count */
MOVW R7, R10 /* R10 is to-pointer */
SUBCC R0,R9, R0
BGE ok
MOVW 0(R0), R0
ok:
MOVW s2+4(FP), R11 /* R11 is from-pointer */
ADD R9,R11, R13 /* R13 is end from-pointer */
ADD R9,R10, R12 /* R12 is end to-pointer */
/*
* easiest test is copy backwards if
* destination string has higher mem address
*/
SUBCC R11,R10, R0
BGU back
/*
* if not at least 4 chars,
* dont even mess around.
* 3 chars to guarantee any
* rounding up to a word
* boundary and 4 characters
* to get at least maybe one
* full word store.
*/
SUBCC $4,R9, R0
BL fout
/*
* test if both pointers
* are similarly word aligned
*/
XOR R10,R11, R7
ANDCC $3,R7, R0
BNE fout
/*
* byte at a time to word align
*/
f1:
ANDCC $3,R10, R0
BE f2
MOVB 0(R11), R16
ADD $1, R11
MOVB R16, 0(R10)
ADD $1, R10
JMP f1
/*
* turn R9 into to-end pointer-15
* copy 16 at a time while theres room.
* R12 is smaller than R13 --
* there are problems if R13 is 0.
*/
f2:
SUB $15,R12, R9
f3:
SUBCC R10,R9, R0
BLEU f4
MOVW 0(R11), R16
MOVW 4(R11), R17
MOVW R16, 0(R10)
MOVW 8(R11), R16
MOVW R17, 4(R10)
MOVW 12(R11), R17
ADD $16, R11
MOVW R16, 8(R10)
MOVW R17, 12(R10)
ADD $16, R10
JMP f3
/*
* turn R9 into to-end pointer-3
* copy 4 at a time while theres room
*/
f4:
SUB $3,R12, R9
f5:
SUBCC R10,R9, R0
BLEU fout
MOVW 0(R11), R16
ADD $4, R11
MOVW R16, 0(R10)
ADD $4, R10
JMP f5
/*
* last loop, copy byte at a time
*/
fout:
SUBCC R11,R13, R0
BLEU ret
MOVB 0(R11), R16
ADD $1, R11
MOVB R16, 0(R10)
ADD $1, R10
JMP fout
/*
* whole thing repeated for backwards
*/
back:
SUBCC $4,R9, R0
BL bout
XOR R12,R13, R7
ANDCC $3,R7, R0
BNE bout
b1:
ANDCC $3,R13, R0
BE b2
MOVB -1(R13), R16
SUB $1, R13
MOVB R16, -1(R12)
SUB $1, R12
JMP b1
b2:
ADD $15,R11, R9
b3:
SUBCC R9,R13, R0
BLEU b4
MOVW -4(R13), R16
MOVW -8(R13), R17
MOVW R16, -4(R12)
MOVW -12(R13), R16
MOVW R17, -8(R12)
MOVW -16(R13), R17
SUB $16, R13
MOVW R16, -12(R12)
MOVW R17, -16(R12)
SUB $16, R12
JMP b3
b4:
ADD $3,R11, R9
b5:
SUBCC R9,R13, R0
BLEU bout
MOVW -4(R13), R16
SUB $4, R13
MOVW R16, -4(R12)
SUB $4, R12
JMP b5
bout:
SUBCC R11,R13, R0
BLEU ret
MOVB -1(R13), R16
SUB $1, R13
MOVB R16, -1(R12)
SUB $1, R12
JMP bout
ret:
MOVW s1+0(FP), R7
RETURN
|
