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Diffstat (limited to 'arch/mn10300/lib/memcpy.S')
-rw-r--r-- | arch/mn10300/lib/memcpy.S | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/arch/mn10300/lib/memcpy.S b/arch/mn10300/lib/memcpy.S new file mode 100644 index 000000000000..25fb9bb2604f --- /dev/null +++ b/arch/mn10300/lib/memcpy.S | |||
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1 | /* MN10300 Optimised simple memory to memory copy | ||
2 | * | ||
3 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. | ||
4 | * Written by David Howells (dhowells@redhat.com) | ||
5 | * | ||
6 | * This program is free software; you can redistribute it and/or | ||
7 | * modify it under the terms of the GNU General Public Licence | ||
8 | * as published by the Free Software Foundation; either version | ||
9 | * 2 of the Licence, or (at your option) any later version. | ||
10 | */ | ||
11 | #include <asm/cache.h> | ||
12 | |||
13 | .section .text | ||
14 | .balign L1_CACHE_BYTES | ||
15 | |||
16 | ############################################################################### | ||
17 | # | ||
18 | # void *memcpy(void *dst, const void *src, size_t n) | ||
19 | # | ||
20 | ############################################################################### | ||
21 | .globl memcpy | ||
22 | .type memcpy,@function | ||
23 | memcpy: | ||
24 | movm [d2,d3],(sp) | ||
25 | mov d0,(12,sp) | ||
26 | mov d1,(16,sp) | ||
27 | mov (20,sp),d2 # count | ||
28 | mov d0,a0 # dst | ||
29 | mov d1,a1 # src | ||
30 | mov d0,e3 # the return value | ||
31 | |||
32 | cmp +0,d2 | ||
33 | beq memcpy_done # return if zero-length copy | ||
34 | |||
35 | # see if the three parameters are all four-byte aligned | ||
36 | or d0,d1,d3 | ||
37 | or d2,d3 | ||
38 | and +3,d3 | ||
39 | bne memcpy_1 # jump if not | ||
40 | |||
41 | # we want to transfer as much as we can in chunks of 32 bytes | ||
42 | cmp +31,d2 | ||
43 | bls memcpy_4_remainder # 4-byte aligned remainder | ||
44 | |||
45 | movm [exreg1],(sp) | ||
46 | add -32,d2 | ||
47 | mov +32,d3 | ||
48 | |||
49 | memcpy_4_loop: | ||
50 | mov (a1+),d0 | ||
51 | mov (a1+),d1 | ||
52 | mov (a1+),e0 | ||
53 | mov (a1+),e1 | ||
54 | mov (a1+),e4 | ||
55 | mov (a1+),e5 | ||
56 | mov (a1+),e6 | ||
57 | mov (a1+),e7 | ||
58 | mov d0,(a0+) | ||
59 | mov d1,(a0+) | ||
60 | mov e0,(a0+) | ||
61 | mov e1,(a0+) | ||
62 | mov e4,(a0+) | ||
63 | mov e5,(a0+) | ||
64 | mov e6,(a0+) | ||
65 | mov e7,(a0+) | ||
66 | |||
67 | sub d3,d2 | ||
68 | bcc memcpy_4_loop | ||
69 | |||
70 | movm (sp),[exreg1] | ||
71 | add d3,d2 | ||
72 | beq memcpy_4_no_remainder | ||
73 | |||
74 | memcpy_4_remainder: | ||
75 | # cut 4-7 words down to 0-3 | ||
76 | cmp +16,d2 | ||
77 | bcs memcpy_4_three_or_fewer_words | ||
78 | mov (a1+),d0 | ||
79 | mov (a1+),d1 | ||
80 | mov (a1+),e0 | ||
81 | mov (a1+),e1 | ||
82 | mov d0,(a0+) | ||
83 | mov d1,(a0+) | ||
84 | mov e0,(a0+) | ||
85 | mov e1,(a0+) | ||
86 | add -16,d2 | ||
87 | beq memcpy_4_no_remainder | ||
88 | |||
89 | # copy the remaining 1, 2 or 3 words | ||
90 | memcpy_4_three_or_fewer_words: | ||
91 | cmp +8,d2 | ||
92 | bcs memcpy_4_one_word | ||
93 | beq memcpy_4_two_words | ||
94 | mov (a1+),d0 | ||
95 | mov d0,(a0+) | ||
96 | memcpy_4_two_words: | ||
97 | mov (a1+),d0 | ||
98 | mov d0,(a0+) | ||
99 | memcpy_4_one_word: | ||
100 | mov (a1+),d0 | ||
101 | mov d0,(a0+) | ||
102 | |||
103 | memcpy_4_no_remainder: | ||
104 | # check we copied the correct amount | ||
105 | # TODO: REMOVE CHECK | ||
106 | sub e3,a0,d2 | ||
107 | mov (20,sp),d1 | ||
108 | cmp d2,d1 | ||
109 | beq memcpy_done | ||
110 | break | ||
111 | break | ||
112 | break | ||
113 | |||
114 | memcpy_done: | ||
115 | mov e3,a0 | ||
116 | ret [d2,d3],8 | ||
117 | |||
118 | # handle misaligned copying | ||
119 | memcpy_1: | ||
120 | add -1,d2 | ||
121 | mov +1,d3 | ||
122 | setlb # setlb requires the next insns | ||
123 | # to occupy exactly 4 bytes | ||
124 | |||
125 | sub d3,d2 | ||
126 | movbu (a1),d0 | ||
127 | movbu d0,(a0) | ||
128 | add_add d3,a1,d3,a0 | ||
129 | lcc | ||
130 | |||
131 | mov e3,a0 | ||
132 | ret [d2,d3],8 | ||
133 | |||
134 | memcpy_end: | ||
135 | .size memcpy, memcpy_end-memcpy | ||