hashptr.h

/*
 * This file is part of libFirm.
 * Copyright (C) 2012 University of Karlsruhe.
 */

#ifndef FIRM_ADT_HASHPTR_H
#define FIRM_ADT_HASHPTR_H

#include <stddef.h>

#include "../begin.h"

#define _FIRM_FNV_OFFSET_BASIS 2166136261U
#define _FIRM_FNV_FNV_PRIME    16777619U

static inline unsigned hash_data(unsigned char const *data, size_t bytes)
{
    unsigned hash = _FIRM_FNV_OFFSET_BASIS;
    for (size_t i = 0; i < bytes; ++i) {
        hash *= _FIRM_FNV_FNV_PRIME;
        hash ^= data[i];
    }

    return hash;
}

static inline unsigned hash_str(char const *const str)
{
    unsigned hash = _FIRM_FNV_OFFSET_BASIS;
    for(char const *c = str; *c != '\0'; ++c) {
        hash *= _FIRM_FNV_FNV_PRIME;
        hash ^= *c;
    }

    return hash;
}

static inline unsigned hash_ptr(void const *const ptr)
{
    return (unsigned)(((char const *)ptr - (char const *)0) >> 3);
}

static inline unsigned hash_combine(unsigned const x, unsigned const y)
{
    unsigned hash = _FIRM_FNV_OFFSET_BASIS;
    hash *= _FIRM_FNV_FNV_PRIME;
    hash ^= x;
    hash *= _FIRM_FNV_FNV_PRIME;
    hash ^= y;
    return hash;
}

#include "../end.h"

#endif