glibc/sysdeps/alpha/string-fza.h

/* Basic zero byte detection.  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_FZA_H
#define _STRING_FZA_H 1

#include <string-misc.h>
#include <string-optype.h>

/* The CMPBGE instruction creates a bit mask rather than a byte mask.
   However, if we narrow find_t to either 'int' or 'uint8_t', we get
   unnecessary truncation instructions from the 'unsigned long' type
   returned by __builtin_alpha_cmpbge.  */
typedef op_t find_t;

static __always_inline find_t
find_zero_all (op_t x)
{
  return __builtin_alpha_cmpbge (0, x);
}

static __always_inline find_t
find_eq_all (op_t x1, op_t x2)
{
  return find_zero_all (x1 ^ x2);
}

static __always_inline find_t
find_zero_eq_all (op_t x1, op_t x2)
{
  return find_zero_all (x1) | find_zero_all (x1 ^ x2);
}

static __always_inline find_t
find_zero_ne_all (op_t x1, op_t x2)
{
  return find_zero_all (x1) | (find_zero_all (x1 ^ x2) ^ 0xff);
}

/* 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

#endif /* _STRING_FZA_H */