1/*
2 * Copyright (c) 2019 Inria
3 * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met: redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer;
10 * redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution;
13 * neither the name of the copyright holders nor the names of its
14 * contributors may be used to endorse or promote products derived from
15 * this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 * Authors: Daniel Carvalho
30 */
31
32#ifndef __BASE_FILTERS_MULTI_BIT_SEL_BLOOM_FILTER_HH__
33#define __BASE_FILTERS_MULTI_BIT_SEL_BLOOM_FILTER_HH__
34
35#include "base/filters/base.hh"
36
37struct BloomFilterMultiBitSelParams;
38
39namespace BloomFilter {
40
41/**
42 * The MultiBitSel Bloom Filter associates an address to multiple entries
43 * through the use of multiple hash functions.
44 */
45class MultiBitSel : public Base
46{
47  public:
48    MultiBitSel(const BloomFilterMultiBitSelParams* p);
49    ~MultiBitSel();
50
51    void set(Addr addr) override;
52    int getCount(Addr addr) const override;
53
54  protected:
55    /**
56     * Apply the selected the hash functions to an address.
57     *
58     * @param addr The address to hash.
59     * @param hash_number Index of the hash function to be used.
60     */
61    virtual int hash(Addr addr, int hash_number) const;
62
63    /** Number of hashes. */
64    const int numHashes;
65
66    /** Size of the filter when doing parallel hashing. */
67    const int parFilterSize;
68
69    /** Whether hashing should be performed in parallel. */
70    const bool isParallel;
71
72  private:
73    /**
74     * Bit offset from block number. Used to simulate bit selection hashing
75     * on larger than cache-line granularities, by skipping some bits.
76     */
77    const int skipBits;
78};
79
80} // namespace BloomFilter
81
82#endif // __BASE_FILTERS_MULTI_BIT_SEL_BLOOM_FILTER_HH__
83