brrip_rp.cc revision 12684
112626Sodanrc@yahoo.com.br/** 212626Sodanrc@yahoo.com.br * Copyright (c) 2018 Inria 312626Sodanrc@yahoo.com.br * All rights reserved. 412626Sodanrc@yahoo.com.br * 512626Sodanrc@yahoo.com.br * Redistribution and use in source and binary forms, with or without 612626Sodanrc@yahoo.com.br * modification, are permitted provided that the following conditions are 712626Sodanrc@yahoo.com.br * met: redistributions of source code must retain the above copyright 812626Sodanrc@yahoo.com.br * notice, this list of conditions and the following disclaimer; 912626Sodanrc@yahoo.com.br * redistributions in binary form must reproduce the above copyright 1012626Sodanrc@yahoo.com.br * notice, this list of conditions and the following disclaimer in the 1112626Sodanrc@yahoo.com.br * documentation and/or other materials provided with the distribution; 1212626Sodanrc@yahoo.com.br * neither the name of the copyright holders nor the names of its 1312626Sodanrc@yahoo.com.br * contributors may be used to endorse or promote products derived from 1412626Sodanrc@yahoo.com.br * this software without specific prior written permission. 1512626Sodanrc@yahoo.com.br * 1612626Sodanrc@yahoo.com.br * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 1712626Sodanrc@yahoo.com.br * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 1812626Sodanrc@yahoo.com.br * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 1912626Sodanrc@yahoo.com.br * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 2012626Sodanrc@yahoo.com.br * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 2112626Sodanrc@yahoo.com.br * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 2212626Sodanrc@yahoo.com.br * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2312626Sodanrc@yahoo.com.br * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2412626Sodanrc@yahoo.com.br * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2512626Sodanrc@yahoo.com.br * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 2612626Sodanrc@yahoo.com.br * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2712626Sodanrc@yahoo.com.br * 2812626Sodanrc@yahoo.com.br * Authors: Daniel Carvalho 2912626Sodanrc@yahoo.com.br */ 3012626Sodanrc@yahoo.com.br 3112626Sodanrc@yahoo.com.br#include "mem/cache/replacement_policies/brrip_rp.hh" 3212626Sodanrc@yahoo.com.br 3312684Sodanrc@yahoo.com.br#include <memory> 3412684Sodanrc@yahoo.com.br 3512684Sodanrc@yahoo.com.br#include "base/logging.hh" // For fatal_if 3612626Sodanrc@yahoo.com.br#include "base/random.hh" 3712626Sodanrc@yahoo.com.br 3812626Sodanrc@yahoo.com.brBRRIPRP::BRRIPRP(const Params *p) 3912626Sodanrc@yahoo.com.br : BaseReplacementPolicy(p), 4012626Sodanrc@yahoo.com.br maxRRPV(p->max_RRPV), hitPriority(p->hit_priority), btp(p->btp) 4112626Sodanrc@yahoo.com.br{ 4212684Sodanrc@yahoo.com.br fatal_if(maxRRPV <= 0, "max_RRPV should be greater than zero.\n"); 4312684Sodanrc@yahoo.com.br} 4412684Sodanrc@yahoo.com.br 4512684Sodanrc@yahoo.com.brvoid 4612684Sodanrc@yahoo.com.brBRRIPRP::invalidate(const std::shared_ptr<ReplacementData>& replacement_data) 4712684Sodanrc@yahoo.com.brconst 4812684Sodanrc@yahoo.com.br{ 4912684Sodanrc@yahoo.com.br std::shared_ptr<BRRIPReplData> casted_replacement_data = 5012684Sodanrc@yahoo.com.br std::static_pointer_cast<BRRIPReplData>(replacement_data); 5112684Sodanrc@yahoo.com.br 5212684Sodanrc@yahoo.com.br // Set RRPV to an invalid distance 5312684Sodanrc@yahoo.com.br casted_replacement_data->rrpv = maxRRPV + 1; 5412684Sodanrc@yahoo.com.br} 5512684Sodanrc@yahoo.com.br 5612684Sodanrc@yahoo.com.brvoid 5712684Sodanrc@yahoo.com.brBRRIPRP::touch(const std::shared_ptr<ReplacementData>& replacement_data) const 5812684Sodanrc@yahoo.com.br{ 5912684Sodanrc@yahoo.com.br std::shared_ptr<BRRIPReplData> casted_replacement_data = 6012684Sodanrc@yahoo.com.br std::static_pointer_cast<BRRIPReplData>(replacement_data); 6112684Sodanrc@yahoo.com.br 6212684Sodanrc@yahoo.com.br // Update RRPV if not 0 yet 6312684Sodanrc@yahoo.com.br // Every hit in HP mode makes the entry the last to be evicted, while 6412684Sodanrc@yahoo.com.br // in FP mode a hit makes the entry less likely to be evicted 6512684Sodanrc@yahoo.com.br if (hitPriority) { 6612684Sodanrc@yahoo.com.br casted_replacement_data->rrpv = 0; 6712684Sodanrc@yahoo.com.br } else if (casted_replacement_data->rrpv > 0) { 6812684Sodanrc@yahoo.com.br casted_replacement_data->rrpv--; 6912626Sodanrc@yahoo.com.br } 7012626Sodanrc@yahoo.com.br} 7112626Sodanrc@yahoo.com.br 7212626Sodanrc@yahoo.com.brvoid 7312684Sodanrc@yahoo.com.brBRRIPRP::reset(const std::shared_ptr<ReplacementData>& replacement_data) const 7412626Sodanrc@yahoo.com.br{ 7512684Sodanrc@yahoo.com.br std::shared_ptr<BRRIPReplData> casted_replacement_data = 7612684Sodanrc@yahoo.com.br std::static_pointer_cast<BRRIPReplData>(replacement_data); 7712626Sodanrc@yahoo.com.br 7812684Sodanrc@yahoo.com.br // Reset RRPV 7912684Sodanrc@yahoo.com.br // Replacement data is inserted as "long re-reference" if lower than btp, 8012684Sodanrc@yahoo.com.br // "distant re-reference" otherwise 8112684Sodanrc@yahoo.com.br if (random_mt.random<unsigned>(1, 100) <= btp) { 8212684Sodanrc@yahoo.com.br casted_replacement_data->rrpv = maxRRPV-1; 8312684Sodanrc@yahoo.com.br } else { 8412684Sodanrc@yahoo.com.br casted_replacement_data->rrpv = maxRRPV; 8512626Sodanrc@yahoo.com.br } 8612626Sodanrc@yahoo.com.br} 8712626Sodanrc@yahoo.com.br 8812684Sodanrc@yahoo.com.brReplaceableEntry* 8912684Sodanrc@yahoo.com.brBRRIPRP::getVictim(const ReplacementCandidates& candidates) const 9012626Sodanrc@yahoo.com.br{ 9112626Sodanrc@yahoo.com.br // There must be at least one replacement candidate 9212626Sodanrc@yahoo.com.br assert(candidates.size() > 0); 9312626Sodanrc@yahoo.com.br 9412684Sodanrc@yahoo.com.br // Use first candidate as dummy victim 9512684Sodanrc@yahoo.com.br ReplaceableEntry* victim = candidates[0]; 9612684Sodanrc@yahoo.com.br 9712684Sodanrc@yahoo.com.br // Store victim->rrpv in a variable to improve code readability 9812684Sodanrc@yahoo.com.br int victim_RRPV = std::static_pointer_cast<BRRIPReplData>( 9912684Sodanrc@yahoo.com.br victim->replacementData)->rrpv; 10012684Sodanrc@yahoo.com.br 10112684Sodanrc@yahoo.com.br // Visit all candidates to find victim 10212626Sodanrc@yahoo.com.br for (const auto& candidate : candidates) { 10312684Sodanrc@yahoo.com.br // Get candidate's rrpv 10412684Sodanrc@yahoo.com.br int candidate_RRPV = std::static_pointer_cast<BRRIPReplData>( 10512684Sodanrc@yahoo.com.br candidate->replacementData)->rrpv; 10612684Sodanrc@yahoo.com.br 10712684Sodanrc@yahoo.com.br // Stop searching for victims if an invalid entry is found 10812684Sodanrc@yahoo.com.br if (candidate_RRPV == maxRRPV + 1) { 10912684Sodanrc@yahoo.com.br return candidate; 11012684Sodanrc@yahoo.com.br // Update victim entry if necessary 11112684Sodanrc@yahoo.com.br } else if (candidate_RRPV > victim_RRPV) { 11212684Sodanrc@yahoo.com.br victim = candidate; 11312684Sodanrc@yahoo.com.br victim_RRPV = candidate_RRPV; 11412626Sodanrc@yahoo.com.br } 11512626Sodanrc@yahoo.com.br } 11612626Sodanrc@yahoo.com.br 11712684Sodanrc@yahoo.com.br // Get difference of victim's RRPV to the highest possible RRPV in 11812684Sodanrc@yahoo.com.br // order to update the RRPV of all the other entries accordingly 11912684Sodanrc@yahoo.com.br int diff = maxRRPV - victim_RRPV; 12012626Sodanrc@yahoo.com.br 12112626Sodanrc@yahoo.com.br // No need to update RRPV if there is no difference 12212626Sodanrc@yahoo.com.br if (diff > 0){ 12312626Sodanrc@yahoo.com.br // Update RRPV of all candidates 12412626Sodanrc@yahoo.com.br for (const auto& candidate : candidates) { 12512684Sodanrc@yahoo.com.br std::static_pointer_cast<BRRIPReplData>( 12612684Sodanrc@yahoo.com.br candidate->replacementData)->rrpv += diff; 12712626Sodanrc@yahoo.com.br } 12812626Sodanrc@yahoo.com.br } 12912626Sodanrc@yahoo.com.br 13012684Sodanrc@yahoo.com.br return victim; 13112684Sodanrc@yahoo.com.br} 13212626Sodanrc@yahoo.com.br 13312684Sodanrc@yahoo.com.brstd::shared_ptr<ReplacementData> 13412684Sodanrc@yahoo.com.brBRRIPRP::instantiateEntry() 13512684Sodanrc@yahoo.com.br{ 13612684Sodanrc@yahoo.com.br return std::shared_ptr<ReplacementData>(new BRRIPReplData(maxRRPV)); 13712626Sodanrc@yahoo.com.br} 13812626Sodanrc@yahoo.com.br 13912626Sodanrc@yahoo.com.brBRRIPRP* 14012626Sodanrc@yahoo.com.brBRRIPRPParams::create() 14112626Sodanrc@yahoo.com.br{ 14212626Sodanrc@yahoo.com.br return new BRRIPRP(this); 14312626Sodanrc@yahoo.com.br} 144