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53 lines
1.7 KiB
C
53 lines
1.7 KiB
C
/* Shift unaligned word read Generic C version.
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Copyright (C) 2023-2025 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef _STRING_SHIFT_H
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#define _STRING_SHIFT_H 1
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#include <endian.h>
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#include <limits.h>
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#include <stdint.h>
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#include <string-fza.h>
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/* Return the mask WORD shifted based on S_INT address value, to ignore
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values not presented in the aligned word read. */
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static __always_inline find_t
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shift_find (find_t word, uintptr_t s)
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{
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if (__BYTE_ORDER == __LITTLE_ENDIAN)
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return word >> (CHAR_BIT * (s % sizeof (op_t)));
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else
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return word << (CHAR_BIT * (s % sizeof (op_t)));
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}
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/* Mask off the bits defined for the S alignment value, or return WORD if
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S is 0. */
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static __always_inline find_t
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shift_find_last (find_t word, uintptr_t s)
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{
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s = s % sizeof (op_t);
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if (s == 0)
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return word;
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if (__BYTE_ORDER == __LITTLE_ENDIAN)
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return word & ~(((op_t)-1) << (s * CHAR_BIT));
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else
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return word & ~(((op_t)-1) >> (s * CHAR_BIT));
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}
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#endif /* _STRING_SHIFT_H */
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