| Guo Ren | c5af58b | 2018-09-05 14:25:18 +0800 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. |
| 3 | |
| 4 | #include <linux/linkage.h> |
| 5 | #include "sysdep.h" |
| 6 | |
| 7 | ENTRY(memcmp) |
| 8 | /* Test if len less than 4 bytes. */ |
| 9 | mov r3, r0 |
| 10 | movi r0, 0 |
| 11 | mov r12, r4 |
| 12 | cmplti r2, 4 |
| 13 | bt .L_compare_by_byte |
| 14 | |
| 15 | andi r13, r0, 3 |
| 16 | movi r19, 4 |
| 17 | |
| 18 | /* Test if s1 is not 4 bytes aligned. */ |
| 19 | bnez r13, .L_s1_not_aligned |
| 20 | |
| 21 | LABLE_ALIGN |
| 22 | .L_s1_aligned: |
| 23 | /* If dest is aligned, then copy. */ |
| 24 | zext r18, r2, 31, 4 |
| 25 | /* Test if len less than 16 bytes. */ |
| 26 | bez r18, .L_compare_by_word |
| 27 | |
| 28 | .L_compare_by_4word: |
| 29 | /* If aligned, load word each time. */ |
| 30 | ldw r20, (r3, 0) |
| 31 | ldw r21, (r1, 0) |
| 32 | /* If s1[i] != s2[i], goto .L_byte_check. */ |
| 33 | cmpne r20, r21 |
| 34 | bt .L_byte_check |
| 35 | |
| 36 | ldw r20, (r3, 4) |
| 37 | ldw r21, (r1, 4) |
| 38 | cmpne r20, r21 |
| 39 | bt .L_byte_check |
| 40 | |
| 41 | ldw r20, (r3, 8) |
| 42 | ldw r21, (r1, 8) |
| 43 | cmpne r20, r21 |
| 44 | bt .L_byte_check |
| 45 | |
| 46 | ldw r20, (r3, 12) |
| 47 | ldw r21, (r1, 12) |
| 48 | cmpne r20, r21 |
| 49 | bt .L_byte_check |
| 50 | |
| 51 | PRE_BNEZAD (r18) |
| 52 | addi a3, 16 |
| 53 | addi a1, 16 |
| 54 | |
| 55 | BNEZAD (r18, .L_compare_by_4word) |
| 56 | |
| 57 | .L_compare_by_word: |
| 58 | zext r18, r2, 3, 2 |
| 59 | bez r18, .L_compare_by_byte |
| 60 | .L_compare_by_word_loop: |
| 61 | ldw r20, (r3, 0) |
| 62 | ldw r21, (r1, 0) |
| 63 | addi r3, 4 |
| 64 | PRE_BNEZAD (r18) |
| 65 | cmpne r20, r21 |
| 66 | addi r1, 4 |
| 67 | bt .L_byte_check |
| 68 | BNEZAD (r18, .L_compare_by_word_loop) |
| 69 | |
| 70 | .L_compare_by_byte: |
| 71 | zext r18, r2, 1, 0 |
| 72 | bez r18, .L_return |
| 73 | .L_compare_by_byte_loop: |
| 74 | ldb r0, (r3, 0) |
| 75 | ldb r4, (r1, 0) |
| 76 | addi r3, 1 |
| 77 | subu r0, r4 |
| 78 | PRE_BNEZAD (r18) |
| 79 | addi r1, 1 |
| 80 | bnez r0, .L_return |
| 81 | BNEZAD (r18, .L_compare_by_byte_loop) |
| 82 | |
| 83 | .L_return: |
| 84 | mov r4, r12 |
| 85 | rts |
| 86 | |
| 87 | # ifdef __CSKYBE__ |
| 88 | /* d[i] != s[i] in word, so we check byte 0. */ |
| 89 | .L_byte_check: |
| 90 | xtrb0 r0, r20 |
| 91 | xtrb0 r2, r21 |
| 92 | subu r0, r2 |
| 93 | bnez r0, .L_return |
| 94 | |
| 95 | /* check byte 1 */ |
| 96 | xtrb1 r0, r20 |
| 97 | xtrb1 r2, r21 |
| 98 | subu r0, r2 |
| 99 | bnez r0, .L_return |
| 100 | |
| 101 | /* check byte 2 */ |
| 102 | xtrb2 r0, r20 |
| 103 | xtrb2 r2, r21 |
| 104 | subu r0, r2 |
| 105 | bnez r0, .L_return |
| 106 | |
| 107 | /* check byte 3 */ |
| 108 | xtrb3 r0, r20 |
| 109 | xtrb3 r2, r21 |
| 110 | subu r0, r2 |
| 111 | # else |
| 112 | /* s1[i] != s2[i] in word, so we check byte 3. */ |
| 113 | .L_byte_check: |
| 114 | xtrb3 r0, r20 |
| 115 | xtrb3 r2, r21 |
| 116 | subu r0, r2 |
| 117 | bnez r0, .L_return |
| 118 | |
| 119 | /* check byte 2 */ |
| 120 | xtrb2 r0, r20 |
| 121 | xtrb2 r2, r21 |
| 122 | subu r0, r2 |
| 123 | bnez r0, .L_return |
| 124 | |
| 125 | /* check byte 1 */ |
| 126 | xtrb1 r0, r20 |
| 127 | xtrb1 r2, r21 |
| 128 | subu r0, r2 |
| 129 | bnez r0, .L_return |
| 130 | |
| 131 | /* check byte 0 */ |
| 132 | xtrb0 r0, r20 |
| 133 | xtrb0 r2, r21 |
| 134 | subu r0, r2 |
| 135 | br .L_return |
| 136 | # endif /* !__CSKYBE__ */ |
| 137 | |
| 138 | /* Compare when s1 is not aligned. */ |
| 139 | .L_s1_not_aligned: |
| 140 | sub r13, r19, r13 |
| 141 | sub r2, r13 |
| 142 | .L_s1_not_aligned_loop: |
| 143 | ldb r0, (r3, 0) |
| 144 | ldb r4, (r1, 0) |
| 145 | addi r3, 1 |
| 146 | subu r0, r4 |
| 147 | PRE_BNEZAD (r13) |
| 148 | addi r1, 1 |
| 149 | bnez r0, .L_return |
| 150 | BNEZAD (r13, .L_s1_not_aligned_loop) |
| 151 | br .L_s1_aligned |
| 152 | ENDPROC(memcmp) |