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

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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#include "base/filters/bulk_bloom_filter.hh"
33
34#include <limits>
35
36#include "base/bitfield.hh"
37#include "base/logging.hh"
38#include "params/BloomFilterBulk.hh"
39
40namespace BloomFilter {
41
42Bulk::Bulk(const BloomFilterBulkParams* p)
43 : MultiBitSel(p), sectorBits(floorLog2(parFilterSize))
44{
45 fatal_if((numHashes * sectorBits) >
46 (std::numeric_limits<Addr>::digits - offsetBits),
47 "Sectors need more bits than available");
48}
49
50Bulk::~Bulk()
51{
52}
53
54int
55Bulk::hash(Addr addr, int hash_number) const
56{
57 addr = permute(addr);
58
59 // Get the sector-based c index
60 int c = bits(addr, (offsetBits + (hash_number + 1) * sectorBits) - 1,
61 offsetBits + hash_number * sectorBits);
62 assert(c < filter.size()/numHashes);
63
64 // Transform the sector-based c index into a filder index (v)
65 c += (numHashes - 1 - hash_number) * (filter.size()/numHashes);
66 assert(c < filter.size());
67
68 return c;
69}
70
71Addr
72Bulk::permute(Addr addr) const
73{
74 // permutes the original address bits according to Table 5
75 Addr part1 = bits(addr, offsetBits + 6, offsetBits),
76 part2 = bits(addr, offsetBits + 9),
77 part3 = bits(addr, offsetBits + 11),
78 part4 = bits(addr, offsetBits + 17),
79 part5 = bits(addr, offsetBits + 8, offsetBits + 7),
80 part6 = bits(addr, offsetBits + 10),

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