brrip_rp.cc revision 14211
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 3312727Snikos.nikoleris@arm.com#include <cassert> 3412684Sodanrc@yahoo.com.br#include <memory> 3512684Sodanrc@yahoo.com.br 3612684Sodanrc@yahoo.com.br#include "base/logging.hh" // For fatal_if 3712626Sodanrc@yahoo.com.br#include "base/random.hh" 3812727Snikos.nikoleris@arm.com#include "params/BRRIPRP.hh" 3912626Sodanrc@yahoo.com.br 4012626Sodanrc@yahoo.com.brBRRIPRP::BRRIPRP(const Params *p) 4112626Sodanrc@yahoo.com.br : BaseReplacementPolicy(p), 4214211Sodanrc@yahoo.com.br numRRPVBits(p->num_bits), hitPriority(p->hit_priority), btp(p->btp) 4312626Sodanrc@yahoo.com.br{ 4414211Sodanrc@yahoo.com.br fatal_if(numRRPVBits <= 0, "There should be at least one bit per RRPV.\n"); 4512684Sodanrc@yahoo.com.br} 4612684Sodanrc@yahoo.com.br 4712684Sodanrc@yahoo.com.brvoid 4812684Sodanrc@yahoo.com.brBRRIPRP::invalidate(const std::shared_ptr<ReplacementData>& replacement_data) 4912684Sodanrc@yahoo.com.brconst 5012684Sodanrc@yahoo.com.br{ 5112684Sodanrc@yahoo.com.br std::shared_ptr<BRRIPReplData> casted_replacement_data = 5212684Sodanrc@yahoo.com.br std::static_pointer_cast<BRRIPReplData>(replacement_data); 5312684Sodanrc@yahoo.com.br 5414211Sodanrc@yahoo.com.br // Invalidate entry 5514211Sodanrc@yahoo.com.br casted_replacement_data->valid = false; 5612684Sodanrc@yahoo.com.br} 5712684Sodanrc@yahoo.com.br 5812684Sodanrc@yahoo.com.brvoid 5912684Sodanrc@yahoo.com.brBRRIPRP::touch(const std::shared_ptr<ReplacementData>& replacement_data) const 6012684Sodanrc@yahoo.com.br{ 6112684Sodanrc@yahoo.com.br std::shared_ptr<BRRIPReplData> casted_replacement_data = 6212684Sodanrc@yahoo.com.br std::static_pointer_cast<BRRIPReplData>(replacement_data); 6312684Sodanrc@yahoo.com.br 6412684Sodanrc@yahoo.com.br // Update RRPV if not 0 yet 6512684Sodanrc@yahoo.com.br // Every hit in HP mode makes the entry the last to be evicted, while 6612684Sodanrc@yahoo.com.br // in FP mode a hit makes the entry less likely to be evicted 6712684Sodanrc@yahoo.com.br if (hitPriority) { 6814211Sodanrc@yahoo.com.br casted_replacement_data->rrpv.reset(); 6914211Sodanrc@yahoo.com.br } else { 7012684Sodanrc@yahoo.com.br casted_replacement_data->rrpv--; 7112626Sodanrc@yahoo.com.br } 7212626Sodanrc@yahoo.com.br} 7312626Sodanrc@yahoo.com.br 7412626Sodanrc@yahoo.com.brvoid 7512684Sodanrc@yahoo.com.brBRRIPRP::reset(const std::shared_ptr<ReplacementData>& replacement_data) const 7612626Sodanrc@yahoo.com.br{ 7712684Sodanrc@yahoo.com.br std::shared_ptr<BRRIPReplData> casted_replacement_data = 7812684Sodanrc@yahoo.com.br std::static_pointer_cast<BRRIPReplData>(replacement_data); 7912626Sodanrc@yahoo.com.br 8012684Sodanrc@yahoo.com.br // Reset RRPV 8112684Sodanrc@yahoo.com.br // Replacement data is inserted as "long re-reference" if lower than btp, 8212684Sodanrc@yahoo.com.br // "distant re-reference" otherwise 8314211Sodanrc@yahoo.com.br casted_replacement_data->rrpv.saturate(); 8412684Sodanrc@yahoo.com.br if (random_mt.random<unsigned>(1, 100) <= btp) { 8514211Sodanrc@yahoo.com.br casted_replacement_data->rrpv--; 8612626Sodanrc@yahoo.com.br } 8714211Sodanrc@yahoo.com.br 8814211Sodanrc@yahoo.com.br // Mark entry as ready to be used 8914211Sodanrc@yahoo.com.br casted_replacement_data->valid = true; 9012626Sodanrc@yahoo.com.br} 9112626Sodanrc@yahoo.com.br 9212684Sodanrc@yahoo.com.brReplaceableEntry* 9312684Sodanrc@yahoo.com.brBRRIPRP::getVictim(const ReplacementCandidates& candidates) const 9412626Sodanrc@yahoo.com.br{ 9512626Sodanrc@yahoo.com.br // There must be at least one replacement candidate 9612626Sodanrc@yahoo.com.br assert(candidates.size() > 0); 9712626Sodanrc@yahoo.com.br 9812684Sodanrc@yahoo.com.br // Use first candidate as dummy victim 9912684Sodanrc@yahoo.com.br ReplaceableEntry* victim = candidates[0]; 10012684Sodanrc@yahoo.com.br 10112684Sodanrc@yahoo.com.br // Store victim->rrpv in a variable to improve code readability 10212684Sodanrc@yahoo.com.br int victim_RRPV = std::static_pointer_cast<BRRIPReplData>( 10312684Sodanrc@yahoo.com.br victim->replacementData)->rrpv; 10412684Sodanrc@yahoo.com.br 10512684Sodanrc@yahoo.com.br // Visit all candidates to find victim 10612626Sodanrc@yahoo.com.br for (const auto& candidate : candidates) { 10714211Sodanrc@yahoo.com.br std::shared_ptr<BRRIPReplData> candidate_repl_data = 10814211Sodanrc@yahoo.com.br std::static_pointer_cast<BRRIPReplData>( 10914211Sodanrc@yahoo.com.br candidate->replacementData); 11012684Sodanrc@yahoo.com.br 11112684Sodanrc@yahoo.com.br // Stop searching for victims if an invalid entry is found 11214211Sodanrc@yahoo.com.br if (!candidate_repl_data->valid) { 11312684Sodanrc@yahoo.com.br return candidate; 11414211Sodanrc@yahoo.com.br } 11514211Sodanrc@yahoo.com.br 11612684Sodanrc@yahoo.com.br // Update victim entry if necessary 11714211Sodanrc@yahoo.com.br int candidate_RRPV = candidate_repl_data->rrpv; 11814211Sodanrc@yahoo.com.br if (candidate_RRPV > victim_RRPV) { 11912684Sodanrc@yahoo.com.br victim = candidate; 12012684Sodanrc@yahoo.com.br victim_RRPV = candidate_RRPV; 12112626Sodanrc@yahoo.com.br } 12212626Sodanrc@yahoo.com.br } 12312626Sodanrc@yahoo.com.br 12412684Sodanrc@yahoo.com.br // Get difference of victim's RRPV to the highest possible RRPV in 12512684Sodanrc@yahoo.com.br // order to update the RRPV of all the other entries accordingly 12614211Sodanrc@yahoo.com.br int diff = std::static_pointer_cast<BRRIPReplData>( 12714211Sodanrc@yahoo.com.br victim->replacementData)->rrpv.saturate(); 12812626Sodanrc@yahoo.com.br 12912626Sodanrc@yahoo.com.br // No need to update RRPV if there is no difference 13012626Sodanrc@yahoo.com.br if (diff > 0){ 13112626Sodanrc@yahoo.com.br // Update RRPV of all candidates 13212626Sodanrc@yahoo.com.br for (const auto& candidate : candidates) { 13312684Sodanrc@yahoo.com.br std::static_pointer_cast<BRRIPReplData>( 13412684Sodanrc@yahoo.com.br candidate->replacementData)->rrpv += diff; 13512626Sodanrc@yahoo.com.br } 13612626Sodanrc@yahoo.com.br } 13712626Sodanrc@yahoo.com.br 13812684Sodanrc@yahoo.com.br return victim; 13912684Sodanrc@yahoo.com.br} 14012626Sodanrc@yahoo.com.br 14112684Sodanrc@yahoo.com.brstd::shared_ptr<ReplacementData> 14212684Sodanrc@yahoo.com.brBRRIPRP::instantiateEntry() 14312684Sodanrc@yahoo.com.br{ 14414211Sodanrc@yahoo.com.br return std::shared_ptr<ReplacementData>(new BRRIPReplData(numRRPVBits)); 14512626Sodanrc@yahoo.com.br} 14612626Sodanrc@yahoo.com.br 14712626Sodanrc@yahoo.com.brBRRIPRP* 14812626Sodanrc@yahoo.com.brBRRIPRPParams::create() 14912626Sodanrc@yahoo.com.br{ 15012626Sodanrc@yahoo.com.br return new BRRIPRP(this); 15112626Sodanrc@yahoo.com.br} 152