shithub: sl

ref: 24a71723ffbe92ccbdc088a078d776fb869b52ca
dir: /src/ptrhash.c/

/*
  pointer hash table
  optimized for storing info about particular values
*/

#include "sl.h"

#if defined(BITS64)
static u64int
_pinthash(u64int 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 u32int
_pinthash(u32int 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

#define HTNAME(suffix) ptrhash##suffix
#define HFUNC(v) _pinthash((sl_v)(v))
#define EQFUNC(x, y) ((x) == (y))

#include "htable_c.h"