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Diffstat (limited to 'sysdeps/alpha/string-fzi.h')
-rw-r--r-- | sysdeps/alpha/string-fzi.h | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/sysdeps/alpha/string-fzi.h b/sysdeps/alpha/string-fzi.h new file mode 100644 index 0000000000..aba7ca4f3d --- /dev/null +++ b/sysdeps/alpha/string-fzi.h @@ -0,0 +1,62 @@ +/* string-fzi.h -- zero byte detection; indices. Alpha version. + Copyright (C) 2023 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_FZI_H +#define _STRING_FZI_H + +#include <stdint.h> +#include <string-optype.h> +#include <string-fza.h> + +/* Note that since CMPBGE creates a bit mask rather than a byte mask, + we cannot simply provide a target-specific string-fza.h. */ + +/* A subroutine for the index_zero functions. Given a bitmask C, + return the index of the first bit set in memory order. */ +static __always_inline unsigned int +index_first (find_t c) +{ +#ifdef __alpha_cix__ + return __builtin_ctzl (c); +#else + c = c & -c; + return (c & 0xf0 ? 4 : 0) + (c & 0xcc ? 2 : 0) + (c & 0xaa ? 1 : 0); +#endif +} + +/* Similarly, but return the (memory order) index of the last bit + that is non-zero. Note that only the least 8 bits may be nonzero. */ + +static __always_inline unsigned int +index_last (find_t x) +{ +#ifdef __alpha_cix__ + return __builtin_clzl (x) ^ 63; +#else + unsigned r = 0; + if (x & 0xf0) + r += 4; + if (x & (0xc << r)) + r += 2; + if (x & (0x2 << r)) + r += 1; + return r; +#endif +} + +#endif /* _STRING_FZI_H */ |