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Renamed hashstr to hashfunc and added an integer hash function.

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git-svn-id: svn://svn.cc65.org/cc65/trunk@5155 b7a2c559-68d2-44c3-8de9-860c34a00d81
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uz
2011-08-12 15:32:08 +00:00
parent 434c818d20
commit b8e68bed95
5 changed files with 36 additions and 15 deletions
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94
src/common/hashfunc.c Normal file
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/*****************************************************************************/
/* */
/* hashfunc.c */
/* */
/* Hash functions */
/* */
/* */
/* */
/* (C) 1998-2011, Ullrich von Bassewitz */
/* Roemerstrasse 52 */
/* D-70794 Filderstadt */
/* EMail: uz@cc65.org */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
/* warranty. In no event will the authors be held liable for any damages */
/* arising from the use of this software. */
/* */
/* Permission is granted to anyone to use this software for any purpose, */
/* including commercial applications, and to alter it and redistribute it */
/* freely, subject to the following restrictions: */
/* */
/* 1. The origin of this software must not be misrepresented; you must not */
/* claim that you wrote the original software. If you use this software */
/* in a product, an acknowledgment in the product documentation would be */
/* appreciated but is not required. */
/* 2. Altered source versions must be plainly marked as such, and must not */
/* be misrepresented as being the original software. */
/* 3. This notice may not be removed or altered from any source */
/* distribution. */
/* */
/*****************************************************************************/
/* common */
#include "hashfunc.h"
/*****************************************************************************/
/* Code */
/*****************************************************************************/
unsigned HashInt (unsigned V)
/* Return a hash value for the given integer. The function uses Robert
* Jenkins' 32 bit integer hash function taken from
* http://www.concentric.net/~ttwang/tech/inthash.htm
* For 16 bit integers, the function may be suboptimal.
*/
{
V = (V + 0x7ed55d16) + (V << 12);
V = (V ^ 0xc761c23c) ^ (V >> 19);
V = (V + 0x165667b1) + (V << 5);
V = (V + 0xd3a2646c) ^ (V << 9);
V = (V + 0xfd7046c5) + (V << 3);
V = (V ^ 0xb55a4f09) ^ (V >> 16);
return V;
}
unsigned HashStr (const char* S)
/* Return a hash value for the given string */
{
unsigned L, H;
/* Do the hash */
H = L = 0;
while (*S) {
H = ((H << 3) ^ ((unsigned char) *S++)) + L++;
}
return H;
}
unsigned HashBuf (const StrBuf* S)
/* Return a hash value for the given string buffer */
{
unsigned I, L, H;
/* Do the hash */
H = L = 0;
for (I = 0; I < SB_GetLen (S); ++I) {
H = ((H << 3) ^ ((unsigned char) SB_AtUnchecked (S, I))) + L++;
}
return H;
}