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