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a72cc2b2 | 1 | /* Optimized memcmp implementation for PowerPC476. |
04277e02 | 2 | Copyright (C) 2010-2019 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 PE |
16 | License along with the GNU C Library. If not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
a72cc2b2 LM |
18 | |
19 | #include <sysdep.h> | |
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20 | |
21 | /* memcmp | |
22 | ||
23 | r3:source1 address, return equality | |
24 | r4:source2 address | |
25 | r5:byte count | |
26 | ||
27 | Check 2 words from src1 and src2. If unequal jump to end and | |
28 | return src1 > src2 or src1 < src2. | |
29 | If count = zero check bytes before zero counter and then jump to end and | |
30 | return src1 > src2, src1 < src2 or src1 = src2. | |
31 | If src1 = src2 and no null, repeat. */ | |
32 | ||
b5510883 | 33 | EALIGN (memcmp, 5, 0) |
a72cc2b2 LM |
34 | srwi. r6,r5,5 |
35 | beq L(preword2_count_loop) | |
36 | mtctr r6 | |
37 | clrlwi r5,r5,27 | |
38 | ||
39 | L(word8_compare_loop): | |
40 | lwz r10,0(r3) | |
41 | lwz r6,4(r3) | |
42 | lwz r8,0(r4) | |
43 | lwz r9,4(r4) | |
44 | cmplw cr5,r8,r10 | |
45 | cmplw cr1,r9,r6 | |
46 | bne cr5,L(st2) | |
47 | bne cr1,L(st1) | |
48 | lwz r10,8(r3) | |
49 | lwz r6,12(r3) | |
50 | lwz r8,8(r4) | |
51 | lwz r9,12(r4) | |
52 | cmplw cr5,r8,r10 | |
53 | cmplw cr1,r9,r6 | |
54 | bne cr5,L(st2) | |
55 | bne cr1,L(st1) | |
56 | lwz r10,16(r3) | |
57 | lwz r6,20(r3) | |
58 | lwz r8,16(r4) | |
59 | lwz r9,20(r4) | |
60 | cmplw cr5,r8,r10 | |
61 | cmplw cr1,r9,r6 | |
62 | bne cr5,L(st2) | |
63 | bne cr1,L(st1) | |
64 | lwz r10,24(r3) | |
65 | lwz r6,28(r3) | |
66 | addi r3,r3,0x20 | |
67 | lwz r8,24(r4) | |
68 | lwz r9,28(r4) | |
69 | addi r4,r4,0x20 | |
70 | cmplw cr5,r8,r10 | |
71 | cmplw cr1,r9,r6 | |
72 | bne cr5,L(st2) | |
73 | bne cr1,L(st1) | |
74 | bdnz L(word8_compare_loop) | |
75 | ||
76 | L(preword2_count_loop): | |
77 | srwi. r6,r5,3 | |
78 | beq L(prebyte_count_loop) | |
79 | mtctr r6 | |
80 | clrlwi r5,r5,29 | |
81 | ||
82 | L(word2_count_loop): | |
83 | lwz r10,0(r3) | |
84 | lwz r6,4(r3) | |
85 | addi r3,r3,0x08 | |
86 | lwz r8,0(r4) | |
87 | lwz r9,4(r4) | |
88 | addi r4,r4,0x08 | |
89 | cmplw cr5,r8,r10 | |
90 | cmplw cr1,r9,r6 | |
91 | bne cr5,L(st2) | |
92 | bne cr1,L(st1) | |
93 | bdnz L(word2_count_loop) | |
94 | ||
95 | L(prebyte_count_loop): | |
96 | addi r5,r5,1 | |
97 | mtctr r5 | |
98 | bdz L(end_memcmp) | |
99 | ||
100 | L(byte_count_loop): | |
101 | lbz r6,0(r3) | |
102 | addi r3,r3,0x01 | |
103 | lbz r8,0(r4) | |
104 | addi r4,r4,0x01 | |
105 | cmplw cr5,r8,r6 | |
106 | bne cr5,L(st2) | |
107 | bdnz L(byte_count_loop) | |
108 | ||
109 | L(end_memcmp): | |
110 | addi r3,r0,0 | |
111 | blr | |
112 | ||
113 | L(l_r): | |
114 | addi r3,r0,1 | |
115 | blr | |
116 | ||
117 | L(st1): | |
118 | blt cr1,L(l_r) | |
119 | addi r3,r0,-1 | |
120 | blr | |
121 | ||
122 | L(st2): | |
123 | blt cr5,L(l_r) | |
124 | addi r3,r0,-1 | |
125 | blr | |
b5510883 | 126 | END (memcmp) |
a72cc2b2 LM |
127 | libc_hidden_builtin_def (memcmp) |
128 | weak_alias (memcmp,bcmp) |