| 1 | /* Zero byte detection; indexes. Generic C version. |
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| 2 | Copyright (C) 2023-2024 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 | <http://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #ifndef _STRING_FZC_H |
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| 20 | #define _STRING_FZC_H 1 |
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| 21 | |
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| 22 | #include <endian.h> |
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| 23 | #include <string-fza.h> |
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| 24 | #include <string-fzi.h> |
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| 25 | |
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| 26 | |
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| 27 | /* Given a word X that is known to contain a zero byte, return the index of |
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| 28 | the first such within the word in memory order. */ |
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| 29 | static __always_inline unsigned int |
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| 30 | index_first_zero (op_t x) |
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| 31 | { |
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| 32 | if (__BYTE_ORDER == __LITTLE_ENDIAN) |
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| 33 | x = find_zero_low (x); |
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| 34 | else |
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| 35 | x = find_zero_all (x); |
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| 36 | return index_first (c: x); |
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| 37 | } |
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| 38 | |
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| 39 | /* Similarly, but perform the search for byte equality between X1 and X2. */ |
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| 40 | static __always_inline unsigned int |
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| 41 | index_first_eq (op_t x1, op_t x2) |
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| 42 | { |
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| 43 | if (__BYTE_ORDER == __LITTLE_ENDIAN) |
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| 44 | x1 = find_eq_low (x1, x2); |
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| 45 | else |
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| 46 | x1 = find_eq_all (x1, x2); |
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| 47 | return index_first (c: x1); |
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| 48 | } |
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| 49 | |
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| 50 | /* Similarly, but perform the search for zero within X1 or equality between |
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| 51 | X1 and X2. */ |
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| 52 | static __always_inline unsigned int |
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| 53 | index_first_zero_eq (op_t x1, op_t x2) |
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| 54 | { |
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| 55 | if (__BYTE_ORDER == __LITTLE_ENDIAN) |
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| 56 | x1 = find_zero_eq_low (x1, x2); |
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| 57 | else |
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| 58 | x1 = find_zero_eq_all (x1, x2); |
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| 59 | return index_first (c: x1); |
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| 60 | } |
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| 61 | |
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| 62 | /* Similarly, but perform the search for zero within X1 or inequality between |
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| 63 | X1 and X2. */ |
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| 64 | static __always_inline unsigned int |
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| 65 | index_first_zero_ne (op_t x1, op_t x2) |
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| 66 | { |
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| 67 | return index_first (c: find_zero_ne_all (x1, x2)); |
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| 68 | } |
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| 69 | |
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| 70 | /* Similarly, but search for the last zero within X. */ |
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| 71 | static __always_inline unsigned int |
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| 72 | index_last_zero (op_t x) |
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| 73 | { |
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| 74 | if (__BYTE_ORDER == __LITTLE_ENDIAN) |
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| 75 | x = find_zero_all (x); |
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| 76 | else |
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| 77 | x = find_zero_low (x); |
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| 78 | return index_last (c: x); |
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| 79 | } |
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| 80 | |
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| 81 | static __always_inline unsigned int |
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| 82 | index_last_eq (op_t x1, op_t x2) |
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| 83 | { |
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| 84 | return index_last_zero (x: x1 ^ x2); |
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| 85 | } |
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| 86 | |
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| 87 | #endif /* STRING_FZC_H */ |
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| 88 | |
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