ref: dbead6060a9577e0a013bd98e57d6b592ae4a7e3
dir: /ptrhash.c/
/*
pointer hash table
optimized for storing info about particular values
*/
#include "flisp.h"
#define OP_EQ(x, y) ((x) == (y))
#if defined(BITS64)
static uint64_t
_pinthash(uint64_t key)
{
key = (~key) + (key << 21); // key = (key << 21) - key - 1;
key = key ^ (key >> 24);
key = (key + (key << 3)) + (key << 8); // key * 265
key = key ^ (key >> 14);
key = (key + (key << 2)) + (key << 4); // key * 21
key = key ^ (key >> 28);
key = key + (key << 31);
return key;
}
#else
static uint32_t
_pinthash(uint32_t a)
{
a = (a+0x7ed55d16) + (a<<12);
a = (a^0xc761c23c) ^ (a>>19);
a = (a+0x165667b1) + (a<<5);
a = (a+0xd3a2646c) ^ (a<<9);
a = (a+0xfd7046c5) + (a<<3);
a = (a^0xb55a4f09) ^ (a>>16);
return a;
}
#endif
#include "htable.inc"
HTIMPL(ptrhash, _pinthash, OP_EQ)