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/* Zero byte detection; basics. RISCV 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 _RISCV_STRING_FZA_H
#define _RISCV_STRING_FZA_H 1
#if defined __riscv_zbb || defined __riscv_xtheadbb
/* With bitmap extension we can use orc.b to find all zero bytes. */
# include <string-misc.h>
# include <string-optype.h>
/* The functions return a byte mask. */
typedef op_t find_t;
/* This function returns 0xff for each byte that is zero in X. */
static __always_inline find_t
find_zero_all (op_t x)
{
find_t r;
#ifdef __riscv_xtheadbb
asm ("th.tstnbz %0, %1" : "=r" (r) : "r" (x));
return r;
#else
asm ("orc.b %0, %1" : "=r" (r) : "r" (x));
return ~r;
#endif
}
/* This function returns 0xff for each byte that is equal between X1 and
X2. */
static __always_inline find_t
find_eq_all (op_t x1, op_t x2)
{
return find_zero_all (x1 ^ x2);
}
/* Identify zero bytes in X1 or equality between X1 and X2. */
static __always_inline find_t
find_zero_eq_all (op_t x1, op_t x2)
{
return find_zero_all (x1) | find_eq_all (x1, x2);
}
/* Identify zero bytes in X1 or inequality between X1 and X2. */
static __always_inline find_t
find_zero_ne_all (op_t x1, op_t x2)
{
return find_zero_all (x1) | ~find_eq_all (x1, x2);
}
/* Define the "inexact" versions in terms of the exact versions. */
# define find_zero_low find_zero_all
# define find_eq_low find_eq_all
# define find_zero_eq_low find_zero_eq_all
#else
#include <sysdeps/generic/string-fza.h>
#endif
#endif /* _RISCV_STRING_FZA_H */
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