1  /* Zero byte detection; boolean.  Alpha 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_FZB_H
      20  #define _STRING_FZB_H 1
      21  
      22  #include <sys/cdefs.h>
      23  #include <string-optype.h>
      24  
      25  /* Note that since CMPBGE creates a bit mask rather than a byte mask,
      26     we cannot simply provide a target-specific string-fza.h.  */
      27  
      28  /* Determine if any byte within X is zero.  This is a pure boolean test.  */
      29  
      30  static __always_inline _Bool
      31  has_zero (op_t x)
      32  {
      33    return __builtin_alpha_cmpbge (0, x) != 0;
      34  }
      35  
      36  /* Likewise, but for byte equality between X1 and X2.  */
      37  
      38  static __always_inline _Bool
      39  has_eq (op_t x1, op_t x2)
      40  {
      41    return has_zero (x1 ^ x2);
      42  }
      43  
      44  /* Likewise, but for zeros in X1 and equal bytes between X1 and X2.  */
      45  
      46  static __always_inline _Bool
      47  has_zero_eq (op_t x1, op_t x2)
      48  {
      49    return has_zero (x1) | has_eq (x1, x2);
      50  }
      51  
      52  #endif /* _STRING_FZB_H */