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5f72b005 | 1 | /* The assembly function for memory compare. C-SKY ABIV2 version. |
04277e02 | 2 | Copyright (C) 2018-2019 Free Software Foundation, Inc. |
5f72b005 MH |
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 | |
16 | License along with the GNU C Library. If not, see | |
17 | <http://www.gnu.org/licenses/>. */ | |
18 | ||
19 | #include <sysdep.h> | |
20 | ||
21 | ENTRY (memcmp) | |
22 | /* Test if len less than 4 bytes. */ | |
23 | mov r3, r0 | |
24 | movi r0, 0 | |
25 | mov r12, r4 | |
26 | cmplti r2, 4 | |
27 | jbt .L_compare_by_byte | |
28 | ||
29 | andi r13, r0, 3 | |
30 | movi r19, 4 | |
31 | /* Test if s1 is not 4 bytes aligned. */ | |
32 | bnez r13, .L_s1_not_aligned | |
33 | ||
34 | LABLE_ALIGN | |
35 | .L_s1_aligned: | |
36 | /* If dest is aligned, then copy. */ | |
37 | zext r18, r2, 31, 4 | |
38 | /* Test if len less than 16 bytes. */ | |
39 | bez r18, .L_compare_by_word | |
40 | ||
41 | .L_compare_by_4word: | |
42 | /* If aligned, load word each time. */ | |
43 | ldw r20, (r3, 0) | |
44 | ldw r21, (r1, 0) | |
45 | /* If s1[i] != s2[i], goto .L_byte_check. */ | |
46 | cmpne r20, r21 | |
47 | bt .L_byte_check | |
48 | ||
49 | ldw r20, (r3, 4) | |
50 | ldw r21, (r1, 4) | |
51 | cmpne r20, r21 | |
52 | bt .L_byte_check | |
53 | ||
54 | ldw r20, (r3, 8) | |
55 | ldw r21, (r1, 8) | |
56 | cmpne r20, r21 | |
57 | bt .L_byte_check | |
58 | ||
59 | ldw r20, (r3, 12) | |
60 | ldw r21, (r1, 12) | |
61 | cmpne r20, r21 | |
62 | bt .L_byte_check | |
63 | ||
64 | PRE_BNEZAD (r18) | |
65 | addi a3, 16 | |
66 | addi a1, 16 | |
67 | ||
68 | BNEZAD (r18, .L_compare_by_4word) | |
69 | ||
70 | .L_compare_by_word: | |
71 | zext r18, r2, 3, 2 | |
72 | bez r18, .L_compare_by_byte | |
73 | .L_compare_by_word_loop: | |
74 | ldw r20, (r3, 0) | |
75 | ldw r21, (r1, 0) | |
76 | addi r3, 4 | |
77 | PRE_BNEZAD (r18) | |
78 | cmpne r20, r21 | |
79 | addi r1, 4 | |
80 | bt .L_byte_check | |
81 | BNEZAD (r18, .L_compare_by_word_loop) | |
82 | ||
83 | .L_compare_by_byte: | |
84 | zext r18, r2, 1, 0 | |
85 | bez r18, .L_return | |
86 | .L_compare_by_byte_loop: | |
87 | ldb r0, (r3, 0) | |
88 | ldb r4, (r1, 0) | |
89 | addi r3, 1 | |
90 | subu r0, r4 | |
91 | PRE_BNEZAD (r18) | |
92 | addi r1, 1 | |
93 | bnez r0, .L_return | |
94 | BNEZAD (r18, .L_compare_by_byte_loop) | |
95 | ||
96 | .L_return: | |
97 | mov r4, r12 | |
98 | rts | |
99 | ||
100 | /* s1[i] != s2[i] in word, so we check byte 3. */ | |
101 | .L_byte_check: | |
102 | xtrb3 r0, r20 | |
103 | xtrb3 r2, r21 | |
104 | subu r0, r2 | |
105 | bnez r0, .L_return | |
106 | ||
107 | /* check byte 2 */ | |
108 | xtrb2 r0, r20 | |
109 | xtrb2 r2, r21 | |
110 | subu r0, r2 | |
111 | bnez r0, .L_return | |
112 | ||
113 | /* check byte 1 */ | |
114 | xtrb1 r0, r20 | |
115 | xtrb1 r2, r21 | |
116 | subu r0, r2 | |
117 | bnez r0, .L_return | |
118 | ||
119 | /* check byte 0 */ | |
120 | xtrb0 r0, r20 | |
121 | xtrb0 r2, r21 | |
122 | subu r0, r2 | |
123 | br .L_return | |
124 | ||
125 | /* Compare when s1 is not aligned. */ | |
126 | .L_s1_not_aligned: | |
127 | sub r13, r19, r13 | |
128 | sub r2, r13 | |
129 | .L_s1_not_aligned_loop: | |
130 | ldb r0, (r3, 0) | |
131 | ldb r4, (r1, 0) | |
132 | addi r3, 1 | |
133 | subu r0, r4 | |
134 | PRE_BNEZAD (r13) | |
135 | addi r1, 1 | |
136 | bnez r0, .L_return | |
137 | BNEZAD (r13, .L_s1_not_aligned_loop) | |
138 | br .L_s1_aligned | |
139 | END (memcmp) | |
140 | weak_alias (memcmp, bcmp) | |
141 | libc_hidden_def (memcmp) | |
142 | .weak memcmp |