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