| 1 | /* The assembly function for string length. C-SKY ABIV2 version. |
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| 2 | Copyright (C) 2018-2024 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library. If not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #include <sysdep.h> |
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| 20 | |
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| 21 | ENTRY (strlen) |
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| 22 | /* Check if the start addr is aligned. */ |
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| 23 | mov r3, r0 |
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| 24 | andi r1, r0, 3 |
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| 25 | movi r2, 4 |
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| 26 | movi r0, 0 |
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| 27 | bnez r1, .L_start_not_aligned |
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| 28 | |
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| 29 | LABLE_ALIGN |
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| 30 | .L_start_addr_aligned: |
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| 31 | /* Check if all the bytes in the word are not zero. */ |
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| 32 | ldw r1, (r3) |
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| 33 | tstnbz r1 |
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| 34 | bf .L_string_tail |
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| 35 | |
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| 36 | ldw r1, (r3, 4) |
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| 37 | addi r0, 4 |
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| 38 | tstnbz r1 |
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| 39 | bf .L_string_tail |
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| 40 | |
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| 41 | ldw r1, (r3, 8) |
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| 42 | addi r0, 4 |
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| 43 | tstnbz r1 |
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| 44 | bf .L_string_tail |
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| 45 | |
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| 46 | ldw r1, (r3, 12) |
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| 47 | addi r0, 4 |
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| 48 | tstnbz r1 |
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| 49 | bf .L_string_tail |
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| 50 | |
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| 51 | ldw r1, (r3, 16) |
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| 52 | addi r0, 4 |
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| 53 | tstnbz r1 |
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| 54 | bf .L_string_tail |
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| 55 | |
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| 56 | ldw r1, (r3, 20) |
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| 57 | addi r0, 4 |
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| 58 | tstnbz r1 |
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| 59 | bf .L_string_tail |
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| 60 | |
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| 61 | ldw r1, (r3, 24) |
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| 62 | addi r0, 4 |
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| 63 | tstnbz r1 |
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| 64 | bf .L_string_tail |
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| 65 | |
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| 66 | ldw r1, (r3, 28) |
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| 67 | addi r0, 4 |
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| 68 | tstnbz r1 |
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| 69 | bf .L_string_tail |
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| 70 | |
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| 71 | addi r0, 4 |
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| 72 | addi r3, 32 |
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| 73 | br .L_start_addr_aligned |
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| 74 | |
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| 75 | .L_string_tail: |
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| 76 | xtrb3 r3, r1 |
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| 77 | bez r3, .L_return |
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| 78 | addi r0, 1 |
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| 79 | xtrb2 r3, r1 |
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| 80 | bez r3, .L_return |
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| 81 | addi r0, 1 |
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| 82 | xtrb1 r3, r1 |
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| 83 | bez r3, .L_return |
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| 84 | addi r0, 1 |
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| 85 | |
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| 86 | .L_return: |
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| 87 | rts |
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| 88 | |
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| 89 | .L_start_not_aligned: |
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| 90 | sub r2, r2, r1 |
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| 91 | .L_start_not_aligned_loop: |
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| 92 | ldb r1, (r3) |
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| 93 | PRE_BNEZAD (r2) |
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| 94 | addi r3, 1 |
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| 95 | bez r1, .L_return |
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| 96 | addi r0, 1 |
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| 97 | BNEZAD (r2, .L_start_not_aligned_loop) |
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| 98 | br .L_start_addr_aligned |
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| 99 | END (strlen) |
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| 100 | |
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| 101 | libc_hidden_def (strlen) |
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| 102 | .weak strlen |
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| 103 | |
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