1/** 2 * Copyright (c) 2018 Inria 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; --- 40 unchanged lines hidden (view full) --- 49 * 50 * From the original paper, this implementation of RRIP is also called 51 * Static RRIP (SRRIP), as it always inserts entries with the same RRPV. 52 */ 53 54#ifndef __MEM_CACHE_REPLACEMENT_POLICIES_BRRIP_RP_HH__ 55#define __MEM_CACHE_REPLACEMENT_POLICIES_BRRIP_RP_HH__ 56 |
57#include "base/sat_counter.hh" |
58#include "mem/cache/replacement_policies/base.hh" 59 60struct BRRIPRPParams; 61 62class BRRIPRP : public BaseReplacementPolicy 63{ 64 protected: 65 /** BRRIP-specific implementation of replacement data. */ 66 struct BRRIPReplData : ReplacementData 67 { 68 /** 69 * Re-Reference Interval Prediction Value. 70 * Some values have specific names (according to the paper): 71 * 0 -> near-immediate re-rereference interval 72 * max_RRPV-1 -> long re-rereference interval 73 * max_RRPV -> distant re-rereference interval |
74 */ |
75 SatCounter rrpv; |
76 |
77 /** Whether the entry is valid. */ 78 bool valid; 79 |
80 /** 81 * Default constructor. Invalidate data. 82 */ |
83 BRRIPReplData(const int num_bits) 84 : rrpv(num_bits), valid(false) 85 { 86 } |
87 }; 88 89 /** |
90 * Number of RRPV bits. An entry that saturates its RRPV has the longest 91 * possible re-reference interval, that is, it is likely not to be used 92 * in the near future, and is among the best eviction candidates. 93 * A maximum RRPV of 1 implies in a NRU. |
94 */ |
95 const unsigned numRRPVBits; |
96 97 /** 98 * The hit priority (HP) policy replaces entries that do not receive cache 99 * hits over any cache entry that receives a hit, while the frequency 100 * priority (FP) policy replaces infrequently re-referenced entries. 101 */ 102 const bool hitPriority; 103 --- 64 unchanged lines hidden --- |