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a72cc2b2 | 1 | /* Optimized strcpy implementation for PowerPC476. |
2b778ceb | 2 | Copyright (C) 2010-2021 Free Software Foundation, Inc. |
a72cc2b2 LM |
3 | This file is part of the GNU C Library. |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
ab84e3ff | 16 | License along with the GNU C Library. If not, see |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
a72cc2b2 LM |
18 | |
19 | #include <sysdep.h> | |
a72cc2b2 LM |
20 | |
21 | /* strcpy | |
22 | ||
23 | Register Use | |
24 | r3:destination and return address | |
25 | r4:source address | |
26 | r10:temp destination address | |
27 | ||
28 | Implementation description | |
29 | Loop by checking 2 words at a time, with dlmzb. Check if there is a null | |
30 | in the 2 words. If there is a null jump to end checking to determine | |
31 | where in the last 8 bytes it is. Copy the appropriate bytes of the last | |
32 | 8 according to the null position. */ | |
33 | ||
b5510883 | 34 | EALIGN (strcpy, 5, 0) |
a72cc2b2 LM |
35 | neg r7,r4 |
36 | subi r4,r4,1 | |
37 | clrlwi. r8,r7,29 | |
38 | subi r10,r3,1 | |
39 | beq L(pre_word8_loop) | |
40 | mtctr r8 | |
41 | ||
42 | L(loop): | |
43 | lbzu r5,0x01(r4) | |
44 | cmpi cr5,r5,0x0 | |
45 | stbu r5,0x01(r10) | |
46 | beq cr5,L(end_strcpy) | |
47 | bdnz L(loop) | |
48 | ||
49 | L(pre_word8_loop): | |
50 | subi r4,r4,3 | |
51 | subi r10,r10,3 | |
52 | ||
53 | L(word8_loop): | |
54 | lwzu r5,0x04(r4) | |
55 | lwzu r6,0x04(r4) | |
56 | dlmzb. r11,r5,r6 | |
57 | bne L(byte_copy) | |
58 | stwu r5,0x04(r10) | |
59 | stwu r6,0x04(r10) | |
60 | lwzu r5,0x04(r4) | |
61 | lwzu r6,0x04(r4) | |
62 | dlmzb. r11,r5,r6 | |
63 | bne L(byte_copy) | |
64 | stwu r5,0x04(r10) | |
65 | stwu r6,0x04(r10) | |
66 | lwzu r5,0x04(r4) | |
67 | lwzu r6,0x04(r4) | |
68 | dlmzb. r11,r5,r6 | |
69 | bne L(byte_copy) | |
70 | stwu r5,0x04(r10) | |
71 | stwu r6,0x04(r10) | |
72 | lwzu r5,0x04(r4) | |
73 | lwzu r6,0x04(r4) | |
74 | dlmzb. r11,r5,r6 | |
75 | bne L(byte_copy) | |
76 | stwu r5,0x04(r10) | |
77 | stwu r6,0x04(r10) | |
78 | b L(word8_loop) | |
79 | ||
80 | L(last_bytes_copy): | |
81 | stwu r5,0x04(r10) | |
82 | subi r11,r11,4 | |
83 | mtctr r11 | |
84 | addi r10,r10,3 | |
85 | subi r4,r4,1 | |
86 | ||
87 | L(last_bytes_copy_loop): | |
88 | lbzu r5,0x01(r4) | |
89 | stbu r5,0x01(r10) | |
90 | bdnz L(last_bytes_copy_loop) | |
91 | blr | |
92 | ||
93 | L(byte_copy): | |
94 | blt L(last_bytes_copy) | |
95 | mtctr r11 | |
96 | addi r10,r10,3 | |
97 | subi r4,r4,5 | |
98 | ||
99 | L(last_bytes_copy_loop2): | |
100 | lbzu r5,0x01(r4) | |
101 | stbu r5,0x01(r10) | |
102 | bdnz L(last_bytes_copy_loop2) | |
103 | ||
104 | L(end_strcpy): | |
105 | blr | |
b5510883 | 106 | END (strcpy) |
a72cc2b2 | 107 | libc_hidden_builtin_def (strcpy) |