diff options
Diffstat (limited to 'newlib/libc/sys/linux/iconv/hash-string.h')
-rw-r--r-- | newlib/libc/sys/linux/iconv/hash-string.h | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/newlib/libc/sys/linux/iconv/hash-string.h b/newlib/libc/sys/linux/iconv/hash-string.h new file mode 100644 index 000000000..ae4bcfb3e --- /dev/null +++ b/newlib/libc/sys/linux/iconv/hash-string.h @@ -0,0 +1,60 @@ +/* Implements a string hashing function. + Copyright (C) 1995, 1997, 1998, 2000 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +/* @@ end of prolog @@ */ + +#ifndef PARAMS +# if __STDC__ +# 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; +} |