fifo_rp.cc

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#include "mem/cache/replacement_policies/fifo_rp.hh"
 
#include <cassert>
#include <memory>
 
#include "params/FIFORP.hh"
#include "sim/cur_tick.hh"
 
namespace gem5
{
 
namespace replacement_policy
{
 
FIFO::FIFO(const Params &p)
  : Base(p)
{
}
 
void
FIFO::invalidate(const std::shared_ptr<ReplacementData>& replacement_data)
{
    assert(replacement_data);
 
    // To prioritize these entries to be selected during victimization
    // we set their insertion tick as 0
    std::static_pointer_cast<FIFOReplData>(
        replacement_data)->tickInserted = 0;
}
 
void
FIFO::touch(const std::shared_ptr<ReplacementData>& replacement_data) const
{
    // A touch does not modify the insertion tick. We still check if the data
    // exists to standardize the API
    assert(replacement_data);
}
 
void
FIFO::reset(const std::shared_ptr<ReplacementData>& replacement_data) const
{
    assert(replacement_data);
 
    // Set insertion tick
    std::static_pointer_cast<FIFOReplData>(
        replacement_data)->tickInserted = ++timeTicks;
}
 
ReplaceableEntry*
FIFO::getVictim(const ReplacementCandidates& candidates) const
{
    // There must be at least one replacement candidate
    assert(candidates.size() > 0);
 
    // Visit all candidates to find victim
    ReplaceableEntry* victim = candidates[0];
    for (const auto& candidate : candidates) {
        // Update victim entry if necessary
        if (std::static_pointer_cast<FIFOReplData>(
                    candidate->replacementData)->tickInserted <
                std::static_pointer_cast<FIFOReplData>(
                    victim->replacementData)->tickInserted) {
            victim = candidate;
        }
    }
 
    return victim;
}
 
std::shared_ptr<ReplacementData>
FIFO::instantiateEntry()
{
    return std::shared_ptr<ReplacementData>(new FIFOReplData());
}
 
} // namespace replacement_policy
} // namespace gem5