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Put a better (but slower) string hash function back in since it's only used at lex time now.

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git-svn-id: http://picoc.googlecode.com/svn/trunk@64 21eae674-98b7-11dd-bd71-f92a316d2d60
This commit is contained in:
zik.saleeba 2009-02-03 22:05:11 +00:00
parent 70cc4eae49
commit a9494ff382
1 changed files with 15 additions and 6 deletions
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21
table.c
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@ -1,13 +1,22 @@
#include <string.h> #include <string.h>
#include "picoc.h" #include "picoc.h"
/* quick hash function */ /* hash function for strings */
static unsigned int TableHash(const char *Key, int KeyLen) static unsigned int TableHash(const char *Key, int Len)
{ {
if (KeyLen == 0) unsigned int Hash = Len;
return 0; int Offset;
else int Count;
return ((*Key << 24) | (Key[KeyLen-1] << 16) | (Key[KeyLen >> 1] << 8)) ^ KeyLen;
for (Count = 0, Offset = 8; Count < Len; Count++, Offset+=7)
{
if (Offset > sizeof(unsigned int) * 8 - 7)
Offset -= sizeof(unsigned int) * 8 - 6;
Hash ^= *Key++ << Offset;
}
return Hash;
} }
/* initialise a table */ /* initialise a table */