aboutsummaryrefslogtreecommitdiffstats
path: root/arch/alpha/lib/memmove.S
blob: eb3b6e02242f4b91cffe943b105a04f22f1df249 (plain)
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
170
171
172
173
174
175
176
177
178
179
180
181
/*
 * arch/alpha/lib/memmove.S
 *
 * Barely optimized memmove routine for Alpha EV5.
 *
 * This is hand-massaged output from the original memcpy.c.  We defer to
 * memcpy whenever possible; the backwards copy loops are not unrolled.
 */
        
	.set noat
	.set noreorder
	.text

	.align 4
	.globl memmove
	.ent memmove
memmove:
	ldgp $29, 0($27)
	unop
	nop
	.prologue 1

	addq $16,$18,$4
	addq $17,$18,$5
	cmpule $4,$17,$1		/*  dest + n <= src  */
	cmpule $5,$16,$2		/*  dest >= src + n  */

	bis $1,$2,$1
	mov $16,$0
	xor $16,$17,$2
	bne $1,memcpy			!samegp

	and $2,7,$2			/* Test for src/dest co-alignment.  */
	and $16,7,$1
	cmpule $16,$17,$3
	bne $3,$memmove_up		/* dest < src */

	and $4,7,$1
	bne $2,$misaligned_dn
	unop
	beq $1,$skip_aligned_byte_loop_head_dn

$aligned_byte_loop_head_dn:
	lda $4,-1($4)
	lda $5,-1($5)
	unop
	ble $18,$egress

	ldq_u $3,0($5)
	ldq_u $2,0($4)
	lda $18,-1($18)
	extbl $3,$5,$1

	insbl $1,$4,$1
	mskbl $2,$4,$2
	bis $1,$2,$1
	and $4,7,$6

	stq_u $1,0($4)
	bne $6,$aligned_byte_loop_head_dn

$skip_aligned_byte_loop_head_dn:
	lda $18,-8($18)
	blt $18,$skip_aligned_word_loop_dn

$aligned_word_loop_dn:
	ldq $1,-8($5)
	nop
	lda $5,-8($5)
	lda $18,-8($18)

	stq $1,-8($4)
	nop
	lda $4,-8($4)
	bge $18,$aligned_word_loop_dn

$skip_aligned_word_loop_dn:
	lda $18,8($18)
	bgt $18,$byte_loop_tail_dn
	unop
	ret $31,($26),1

	.align 4
$misaligned_dn:
	nop
	fnop
	unop
	beq $18,$egress

$byte_loop_tail_dn:
	ldq_u $3,-1($5)
	ldq_u $2,-1($4)
	lda $5,-1($5)
	lda $4,-1($4)

	lda $18,-1($18)
	extbl $3,$5,$1
	insbl $1,$4,$1
	mskbl $2,$4,$2

	bis $1,$2,$1
	stq_u $1,0($4)
	bgt $18,$byte_loop_tail_dn
	br $egress

$memmove_up:
	mov $16,$4
	mov $17,$5
	bne $2,$misaligned_up
	beq $1,$skip_aligned_byte_loop_head_up

$aligned_byte_loop_head_up:
	unop
	ble $18,$egress
	ldq_u $3,0($5)
	ldq_u $2,0($4)

	lda $18,-1($18)
	extbl $3,$5,$1
	insbl $1,$4,$1
	mskbl $2,$4,$2

	bis $1,$2,$1
	lda $5,1($5)
	stq_u $1,0($4)
	lda $4,1($4)

	and $4,7,$6
	bne $6,$aligned_byte_loop_head_up

$skip_aligned_byte_loop_head_up:
	lda $18,-8($18)
	blt $18,$skip_aligned_word_loop_up

$aligned_word_loop_up:
	ldq $1,0($5)
	nop
	lda $5,8($5)
	lda $18,-8($18)

	stq $1,0($4)
	nop
	lda $4,8($4)
	bge $18,$aligned_word_loop_up

$skip_aligned_word_loop_up:
	lda $18,8($18)
	bgt $18,$byte_loop_tail_up
	unop
	ret $31,($26),1

	.align 4
$misaligned_up:
	nop
	fnop
	unop
	beq $18,$egress

$byte_loop_tail_up:
	ldq_u $3,0($5)
	ldq_u $2,0($4)
	lda $18,-1($18)
	extbl $3,$5,$1

	insbl $1,$4,$1
	mskbl $2,$4,$2
	bis $1,$2,$1
	stq_u $1,0($4)

	lda $5,1($5)
	lda $4,1($4)
	nop
	bgt $18,$byte_loop_tail_up

$egress:
	ret $31,($26),1
	nop
	nop
	nop

	.end memmove