1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
|
/**
* Copyright (c) 2018 Metempsy Technology Consulting
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Javier Bueno
*/
/**
* Implementation of the Signature Path Prefetcher (v2)
*
* References:
* Path confidence based lookahead prefetching
* Jinchun Kim, Seth H. Pugsley, Paul V. Gratz, A. L. Narasimha Reddy,
* Chris Wilkerson, and Zeshan Chishti. 2016.
* In The 49th Annual IEEE/ACM International Symposium on
* Microarchitecture (MICRO-49). IEEE Press, Piscataway, NJ, USA,
* Article 60, 12 pages.
*/
#ifndef __MEM_CACHE_PREFETCH_SIGNATURE_PATH_V2_HH__
#define __MEM_CACHE_PREFETCH_SIGNATURE_PATH_V2_HH__
#include "mem/cache/prefetch/associative_set.hh"
#include "mem/cache/prefetch/signature_path.hh"
#include "mem/packet.hh"
struct SignaturePathPrefetcherV2Params;
class SignaturePathPrefetcherV2 : public SignaturePathPrefetcher
{
/** Global History Register entry datatype */
struct GlobalHistoryEntry : public TaggedEntry
{
signature_t signature;
double confidence;
stride_t lastBlock;
stride_t delta;
GlobalHistoryEntry() : signature(0), confidence(0.0), lastBlock(0),
delta(0) {}
};
/** Global History Register */
AssociativeSet<GlobalHistoryEntry> globalHistoryRegister;
double calculateLookaheadConfidence(PatternEntry const &sig,
PatternStrideEntry const &lookahead) const override;
double calculatePrefetchConfidence(PatternEntry const &sig,
PatternStrideEntry const &lookahead) const override;
void increasePatternEntryCounter(PatternEntry &pattern_entry,
PatternStrideEntry &pstride_entry) override;
void handleSignatureTableMiss(stride_t current_block,
signature_t &new_signature, double &new_conf,
stride_t &new_stride) override;
/**
* In this version of the Signature Path Prefetcher, there is no auxiliary
* prefetcher, so this function does not perform any actions.
*/
void auxiliaryPrefetcher(Addr ppn, stride_t current_block, bool is_secure,
std::vector<AddrPriority> &addresses) override
{}
virtual void handlePageCrossingLookahead(signature_t signature,
stride_t last_offset, stride_t delta, double path_confidence)
override;
public:
SignaturePathPrefetcherV2(const SignaturePathPrefetcherV2Params* p);
~SignaturePathPrefetcherV2() {}
};
#endif//__MEM_CACHE_PREFETCH_SIGNATURE_PATH_V2_HH__
|
