| 1 | /* The assembly function for memset. 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 (memset) |
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| 22 | /* Test if len less than 4 bytes. */ |
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| 23 | mov r12, r0 |
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| 24 | cmplti r2, 8 |
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| 25 | bt .L_set_by_byte |
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| 26 | |
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| 27 | andi r13, r0, 3 |
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| 28 | movi r19, 4 |
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| 29 | /* Test if dest is not 4 bytes aligned. */ |
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| 30 | bnez r13, .L_dest_not_aligned |
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| 31 | /* Hardware can handle unaligned access directly. */ |
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| 32 | .L_dest_aligned: |
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| 33 | zextb r1, r1 |
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| 34 | mov r3, r1 |
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| 35 | lsli r1, 8 |
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| 36 | or r1, r3 |
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| 37 | lsli r3, r1, 16 |
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| 38 | or r3, r1 |
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| 39 | |
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| 40 | /* If dest is aligned, then copy. */ |
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| 41 | zext r18, r2, 31, 4 |
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| 42 | /* Test if len less than 16 bytes. */ |
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| 43 | bez r18, .L_len_less_16bytes |
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| 44 | |
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| 45 | LABLE_ALIGN |
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| 46 | .L_len_larger_16bytes: |
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| 47 | stw r3, (r0, 0) |
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| 48 | stw r3, (r0, 4) |
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| 49 | stw r3, (r0, 8) |
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| 50 | stw r3, (r0, 12) |
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| 51 | PRE_BNEZAD (r18) |
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| 52 | addi r0, 16 |
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| 53 | BNEZAD (r18, .L_len_larger_16bytes) |
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| 54 | |
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| 55 | .L_len_less_16bytes: |
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| 56 | zext r18, r2, 3, 2 |
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| 57 | andi r2, 3 |
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| 58 | bez r18, .L_set_by_byte |
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| 59 | .L_len_less_16bytes_loop: |
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| 60 | stw r3, (r0, 0) |
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| 61 | PRE_BNEZAD (r18) |
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| 62 | addi r0, 4 |
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| 63 | BNEZAD (r18, .L_len_less_16bytes_loop) |
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| 64 | |
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| 65 | /* Test if len less than 4 bytes. */ |
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| 66 | .L_set_by_byte: |
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| 67 | zext r18, r2, 2, 0 |
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| 68 | bez r18, .L_return |
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| 69 | .L_set_by_byte_loop: |
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| 70 | stb r1, (r0, 0) |
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| 71 | PRE_BNEZAD (r18) |
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| 72 | addi r0, 1 |
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| 73 | BNEZAD (r18, .L_set_by_byte_loop) |
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| 74 | |
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| 75 | .L_return: |
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| 76 | mov r0, r12 |
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| 77 | rts |
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| 78 | |
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| 79 | /* If dest is not aligned, just set some bytes makes the dest |
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| 80 | align. */ |
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| 81 | |
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| 82 | .L_dest_not_aligned: |
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| 83 | sub r13, r19, r13 |
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| 84 | sub r2, r13 |
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| 85 | .L_dest_not_aligned_loop: |
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| 86 | /* Makes the dest align. */ |
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| 87 | stb r1, (r0, 0) |
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| 88 | PRE_BNEZAD (r13) |
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| 89 | addi r0, 1 |
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| 90 | BNEZAD (r13, .L_dest_not_aligned_loop) |
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| 91 | cmplti r2, 8 |
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| 92 | bt .L_set_by_byte |
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| 93 | /* Check whether the src is aligned. */ |
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| 94 | br .L_dest_aligned |
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| 95 | END (memset) |
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| 96 | |
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| 97 | libc_hidden_builtin_def (memset) |
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| 98 | .weak memset |
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| 99 | |
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