stride.hh revision 8229 
1/*
2 * Copyright (c) 2005 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Ron Dreslinski
29 */
30
31/**
32 * @file
33 * Describes a strided prefetcher.
34 */
35
36#ifndef __MEM_CACHE_PREFETCH_STRIDE_PREFETCHER_HH__
37#define __MEM_CACHE_PREFETCH_STRIDE_PREFETCHER_HH__
38
39#include <climits>
40
41#include "mem/cache/prefetch/base.hh"
42
43class StridePrefetcher : public BasePrefetcher
44{
45  protected:
46
47    static const int Max_Contexts = 64;
48
49    // These constants need to be changed with the type of the
50    // 'confidence' field below.
51    static const int Max_Conf = INT_MAX;
52    static const int Min_Conf = INT_MIN;
53
54    class StrideEntry
55    {
56      public:
57        Addr instAddr;
58        Addr missAddr;
59        int stride;
60        int confidence;
61    };
62
63    Addr *lastMissAddr[Max_Contexts];
64
65    std::list<StrideEntry*> table[Max_Contexts];
66    Tick latency;
67    int degree;
68    bool useContextId;
69
70  public:
71
72    StridePrefetcher(const BaseCacheParams *p)
73        : BasePrefetcher(p), latency(p->prefetch_latency),
74          degree(p->prefetch_degree), useContextId(p->prefetch_use_cpu_id)
75    {
76    }
77
78    ~StridePrefetcher() {}
79
80    void calculatePrefetch(PacketPtr &pkt, std::list<Addr> &addresses,
81                           std::list<Tick> &delays);
82};
83
84#endif // __MEM_CACHE_PREFETCH_STRIDE_PREFETCHER_HH__
85