sysdeps/alpha/string-fzb.h

   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 */