Mercurial > hg > CbC > CbC_gcc
diff intl/hash-string.h @ 0:a06113de4d67
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author | kent <kent@cr.ie.u-ryukyu.ac.jp> |
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date | Fri, 17 Jul 2009 14:47:48 +0900 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/intl/hash-string.h Fri Jul 17 14:47:48 2009 +0900 @@ -0,0 +1,59 @@ +/* Description of GNU message catalog format: string hashing function. + Copyright (C) 1995, 1997, 1998, 2000, 2001 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify it + under the terms of the GNU Library General Public License as published + by the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, + USA. */ + +/* @@ end of prolog @@ */ + +#ifndef PARAMS +# if __STDC__ || defined __GNUC__ || defined __SUNPRO_C || defined __cplusplus || __PROTOTYPES +# define PARAMS(Args) Args +# else +# define PARAMS(Args) () +# endif +#endif + +/* We assume to have `unsigned long int' value with at least 32 bits. */ +#define HASHWORDBITS 32 + + +/* Defines the so called `hashpjw' function by P.J. Weinberger + [see Aho/Sethi/Ullman, COMPILERS: Principles, Techniques and Tools, + 1986, 1987 Bell Telephone Laboratories, Inc.] */ +static unsigned long int hash_string PARAMS ((const char *__str_param)); + +static inline unsigned long int +hash_string (str_param) + const char *str_param; +{ + unsigned long int hval, g; + const char *str = str_param; + + /* Compute the hash value for the given string. */ + hval = 0; + while (*str != '\0') + { + hval <<= 4; + hval += (unsigned long int) *str++; + g = hval & ((unsigned long int) 0xf << (HASHWORDBITS - 4)); + if (g != 0) + { + hval ^= g >> (HASHWORDBITS - 8); + hval ^= g; + } + } + return hval; +}