| 1 | /* Shift unaligned word read 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_SHIFT_H |
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| 20 | #define _STRING_SHIFT_H 1 |
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| 21 | |
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| 22 | #include <endian.h> |
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| 23 | #include <limits.h> |
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| 24 | #include <stdint.h> |
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| 25 | #include <string-fza.h> |
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| 26 | |
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| 27 | /* Return the mask WORD shifted based on S_INT address value, to ignore |
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| 28 | values not presented in the aligned word read. */ |
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| 29 | static __always_inline find_t |
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| 30 | shift_find (find_t word, uintptr_t s) |
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| 31 | { |
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| 32 | if (__BYTE_ORDER == __LITTLE_ENDIAN) |
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| 33 | return word >> (CHAR_BIT * (s % sizeof (op_t))); |
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| 34 | else |
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| 35 | return word << (CHAR_BIT * (s % sizeof (op_t))); |
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| 36 | } |
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| 37 | |
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| 38 | /* Mask off the bits defined for the S alignment value, or return WORD if |
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| 39 | S is 0. */ |
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| 40 | static __always_inline find_t |
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| 41 | shift_find_last (find_t word, uintptr_t s) |
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| 42 | { |
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| 43 | s = s % sizeof (op_t); |
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| 44 | if (s == 0) |
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| 45 | return word; |
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| 46 | if (__BYTE_ORDER == __LITTLE_ENDIAN) |
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| 47 | return word & ~(((op_t)-1) << (s * CHAR_BIT)); |
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| 48 | else |
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| 49 | return word & ~(((op_t)-1) >> (s * CHAR_BIT)); |
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| 50 | } |
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| 51 | |
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| 52 | #endif /* _STRING_SHIFT_H */ |
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| 53 | |
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