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23 #include <asm/export.h>
24 .set noreorder
25 .set noat
26
27 .align 4
28 .globl memcpy
29 .ent memcpy
30 memcpy:
31 .frame $30,0,$26,0
32 .prologue 0
33
34 mov $16, $0 # E : copy dest to return
35 ble $18, $nomoredata # U : done with the copy?
36 xor $16, $17, $1 # E : are source and dest alignments the same?
37 and $1, 7, $1 # E : are they the same mod 8?
38
39 bne $1, $misaligned # U : Nope - gotta do this the slow way
40
41 and $16, 7, $1 # E : Are both 0mod8?
42 beq $1, $both_0mod8 # U : Yes
43 nop # E :
44
45
46
47
48
49
50
51 $head_align:
52 ldbu $1, 0($17) # L : grab a byte
53 subq $18, 1, $18 # E : count--
54 addq $17, 1, $17 # E : src++
55 stb $1, 0($16) # L :
56 addq $16, 1, $16 # E : dest++
57 and $16, 7, $1 # E : Are we at 0mod8 yet?
58 ble $18, $nomoredata # U : done with the copy?
59 bne $1, $head_align # U :
60
61 $both_0mod8:
62 cmple $18, 127, $1 # E : Can we unroll the loop?
63 bne $1, $no_unroll # U :
64 and $16, 63, $1 # E : get mod64 alignment
65 beq $1, $do_unroll # U : no single quads to fiddle
66
67 $single_head_quad:
68 ldq $1, 0($17) # L : get 8 bytes
69 subq $18, 8, $18 # E : count -= 8
70 addq $17, 8, $17 # E : src += 8
71 nop # E :
72
73 stq $1, 0($16) # L : store
74 addq $16, 8, $16 # E : dest += 8
75 and $16, 63, $1 # E : get mod64 alignment
76 bne $1, $single_head_quad # U : still not fully aligned
77
78 $do_unroll:
79 addq $16, 64, $7 # E : Initial (+1 trip) wh64 address
80 cmple $18, 127, $1 # E : Can we go through the unrolled loop?
81 bne $1, $tail_quads # U : Nope
82 nop # E :
83
84 $unroll_body:
85 wh64 ($7) # L1 : memory subsystem hint: 64 bytes at
86 # ($7) are about to be over-written
87 ldq $6, 0($17) # L0 : bytes 0..7
88 nop # E :
89 nop # E :
90
91 ldq $4, 8($17) # L : bytes 8..15
92 ldq $5, 16($17) # L : bytes 16..23
93 addq $7, 64, $7 # E : Update next wh64 address
94 nop # E :
95
96 ldq $3, 24($17) # L : bytes 24..31
97 addq $16, 64, $1 # E : fallback value for wh64
98 nop # E :
99 nop # E :
100
101 addq $17, 32, $17 # E : src += 32 bytes
102 stq $6, 0($16) # L : bytes 0..7
103 nop # E :
104 nop # E :
105
106 stq $4, 8($16) # L : bytes 8..15
107 stq $5, 16($16) # L : bytes 16..23
108 subq $18, 192, $2 # E : At least two more trips to go?
109 nop # E :
110
111 stq $3, 24($16) # L : bytes 24..31
112 addq $16, 32, $16 # E : dest += 32 bytes
113 nop # E :
114 nop # E :
115
116 ldq $6, 0($17) # L : bytes 0..7
117 ldq $4, 8($17) # L : bytes 8..15
118 cmovlt $2, $1, $7 # E : Latency 2, extra map slot - Use
119
120 nop # E :
121
122 ldq $5, 16($17) # L : bytes 16..23
123 ldq $3, 24($17) # L : bytes 24..31
124 addq $16, 32, $16 # E : dest += 32
125 subq $18, 64, $18 # E : count -= 64
126
127 addq $17, 32, $17 # E : src += 32
128 stq $6, -32($16) # L : bytes 0..7
129 stq $4, -24($16) # L : bytes 8..15
130 cmple $18, 63, $1 # E : At least one more trip?
131
132 stq $5, -16($16) # L : bytes 16..23
133 stq $3, -8($16) # L : bytes 24..31
134 nop # E :
135 beq $1, $unroll_body
136
137 $tail_quads:
138 $no_unroll:
139 .align 4
140 subq $18, 8, $18 # E : At least a quad left?
141 blt $18, $less_than_8 # U : Nope
142 nop # E :
143 nop # E :
144
145 $move_a_quad:
146 ldq $1, 0($17) # L : fetch 8
147 subq $18, 8, $18 # E : count -= 8
148 addq $17, 8, $17 # E : src += 8
149 nop # E :
150
151 stq $1, 0($16) # L : store 8
152 addq $16, 8, $16 # E : dest += 8
153 bge $18, $move_a_quad # U :
154 nop # E :
155
156 $less_than_8:
157 .align 4
158 addq $18, 8, $18 # E : add back for trailing bytes
159 ble $18, $nomoredata # U : All-done
160 nop # E :
161 nop # E :
162
163
164 $tail_bytes:
165 subq $18, 1, $18 # E : count--
166 ldbu $1, 0($17) # L : fetch a byte
167 addq $17, 1, $17 # E : src++
168 nop # E :
169
170 stb $1, 0($16) # L : store a byte
171 addq $16, 1, $16 # E : dest++
172 bgt $18, $tail_bytes # U : more to be done?
173 nop # E :
174
175
176 ret $31, ($26), 1 # L0 :
177 nop # E :
178 nop # E :
179 nop # E :
180
181 $misaligned:
182 mov $0, $4 # E : dest temp
183 and $0, 7, $1 # E : dest alignment mod8
184 beq $1, $dest_0mod8 # U : life doesnt totally suck
185 nop
186
187 $aligndest:
188 ble $18, $nomoredata # U :
189 ldbu $1, 0($17) # L : fetch a byte
190 subq $18, 1, $18 # E : count--
191 addq $17, 1, $17 # E : src++
192
193 stb $1, 0($4) # L : store it
194 addq $4, 1, $4 # E : dest++
195 and $4, 7, $1 # E : dest 0mod8 yet?
196 bne $1, $aligndest # U : go until we are aligned.
197
198
199 $dest_0mod8:
200 subq $18, 8, $18 # E : At least a quad left?
201 blt $18, $misalign_tail # U : Nope
202 ldq_u $3, 0($17) # L : seed (rotating load) of 8 bytes
203 nop # E :
204
205 $mis_quad:
206 ldq_u $16, 8($17) # L : Fetch next 8
207 extql $3, $17, $3 # U : masking
208 extqh $16, $17, $1 # U : masking
209 bis $3, $1, $1 # E : merged bytes to store
210
211 subq $18, 8, $18 # E : count -= 8
212 addq $17, 8, $17 # E : src += 8
213 stq $1, 0($4) # L : store 8 (aligned)
214 mov $16, $3 # E : "rotate" source data
215
216 addq $4, 8, $4 # E : dest += 8
217 bge $18, $mis_quad # U : More quads to move
218 nop
219 nop
220
221 $misalign_tail:
222 addq $18, 8, $18 # E : account for tail stuff
223 ble $18, $nomoredata # U :
224 nop
225 nop
226
227 $misalign_byte:
228 ldbu $1, 0($17) # L : fetch 1
229 subq $18, 1, $18 # E : count--
230 addq $17, 1, $17 # E : src++
231 nop # E :
232
233 stb $1, 0($4) # L : store
234 addq $4, 1, $4 # E : dest++
235 bgt $18, $misalign_byte # U : more to go?
236 nop
237
238
239 $nomoredata:
240 ret $31, ($26), 1 # L0 :
241 nop # E :
242 nop # E :
243 nop # E :
244
245 .end memcpy
246 EXPORT_SYMBOL(memcpy)
247
248
249 __memcpy = memcpy
250 .globl __memcpy