mirror of
git://sourceware.org/git/glibc.git
synced 2024-12-15 04:20:28 +08:00
53 lines
1.7 KiB
C
53 lines
1.7 KiB
C
/* Shift unaligned word read Generic C version.
|
|
Copyright (C) 2023-2024 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#ifndef _STRING_SHIFT_H
|
|
#define _STRING_SHIFT_H 1
|
|
|
|
#include <endian.h>
|
|
#include <limits.h>
|
|
#include <stdint.h>
|
|
#include <string-fza.h>
|
|
|
|
/* Return the mask WORD shifted based on S_INT address value, to ignore
|
|
values not presented in the aligned word read. */
|
|
static __always_inline find_t
|
|
shift_find (find_t word, uintptr_t s)
|
|
{
|
|
if (__BYTE_ORDER == __LITTLE_ENDIAN)
|
|
return word >> (CHAR_BIT * (s % sizeof (op_t)));
|
|
else
|
|
return word << (CHAR_BIT * (s % sizeof (op_t)));
|
|
}
|
|
|
|
/* Mask off the bits defined for the S alignment value, or return WORD if
|
|
S is 0. */
|
|
static __always_inline find_t
|
|
shift_find_last (find_t word, uintptr_t s)
|
|
{
|
|
s = s % sizeof (op_t);
|
|
if (s == 0)
|
|
return word;
|
|
if (__BYTE_ORDER == __LITTLE_ENDIAN)
|
|
return word & ~(((op_t)-1) << (s * CHAR_BIT));
|
|
else
|
|
return word & ~(((op_t)-1) >> (s * CHAR_BIT));
|
|
}
|
|
|
|
#endif /* _STRING_SHIFT_H */
|