1  /* Basic zero byte detection.  Generic C version.
       2     Copyright (C) 2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <http://www.gnu.org/licenses/>.  */
      18  
      19  #ifndef _STRING_FZA_H
      20  #define _STRING_FZA_H 1
      21  
      22  #include <string-misc.h>
      23  #include <string-optype.h>
      24  
      25  /* The CMPBGE instruction creates a bit mask rather than a byte mask.
      26     However, if we narrow find_t to either 'int' or 'uint8_t', we get
      27     unnecessary truncation instructions from the 'unsigned long' type
      28     returned by __builtin_alpha_cmpbge.  */
      29  typedef op_t find_t;
      30  
      31  static __always_inline find_t
      32  find_zero_all (op_t x)
      33  {
      34    return __builtin_alpha_cmpbge (0, x);
      35  }
      36  
      37  static __always_inline find_t
      38  find_eq_all (op_t x1, op_t x2)
      39  {
      40    return find_zero_all (x1 ^ x2);
      41  }
      42  
      43  static __always_inline find_t
      44  find_zero_eq_all (op_t x1, op_t x2)
      45  {
      46    return find_zero_all (x1) | find_zero_all (x1 ^ x2);
      47  }
      48  
      49  static __always_inline find_t
      50  find_zero_ne_all (op_t x1, op_t x2)
      51  {
      52    return find_zero_all (x1) | (find_zero_all (x1 ^ x2) ^ 0xff);
      53  }
      54  
      55  /* Define the "inexact" versions in terms of the exact versions.  */
      56  #define find_zero_low		find_zero_all
      57  #define find_eq_low		find_eq_all
      58  #define find_zero_eq_low	find_zero_eq_all
      59  
      60  #endif /* _STRING_FZA_H */