BFRenameLiveRange.cc

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/*
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/**
 * @file BFRenameLiveRange.cc
 *
 * Definition of BFRenameLiveRange class
 *
 * Renames a liverange, consisting of one or more writes,
 * and one or more either register reads or guadrd uses of the register.
 *
 * @author Heikki Kultala 2014-2020(heikki.kultala-no.spam-tuni.fi)
 * @note rating: red
 */
 
#include "BFRenameLiveRange.hh"
 
#include "BF2Scheduler.hh"
#include "RegisterRenamer.hh"
#include "RegisterFile.hh"
#include "LiveRange.hh"
#include "BasicBlock.hh"
#include "TerminalRegister.hh"
#include "Machine.hh"
#include "BUMoveNodeSelector.hh"
#include "BF2ScheduleFront.hh"
#include "MoveGuard.hh"
#include "Guard.hh"
 
 
BFRenameLiveRange::BFRenameLiveRange(
    BF2Scheduler& sched,
    std::shared_ptr<LiveRange> liveRange,
    int targetCycle) :
    BFOptimization(sched), oldReg_(nullptr), liveRange_(liveRange),
    targetCycle_(targetCycle) {}
 
 
bool BFRenameLiveRange::operator()() {
 
    bb_ = &sched_.renamer()->bb();
 
    assert(!liveRange_->reads.empty());
 
    auto rfs = sched_.renamer()->findConnectedRFs(*liveRange_, false);
 
    bool usedAfter = true;
    std::set<TCEString> regs;
 
    if (!ii()) {
 
        regs = sched_.renamer()->findPartiallyUsedRegistersInRFAfterCycle(
            rfs, targetCycle_);
    }
 
    if (regs.empty()) {
        usedAfter = false;
        regs = sched_.renamer()->findFreeRegistersInRF(rfs);
    }
 
    if (regs.empty()) {
        return false;
    }
 
    return renameLiveRange(*liveRange_, *regs.begin(), usedAfter);
}
 
void BFRenameLiveRange::setTerminals() {
 
    TCEString rfName = newReg_.substr(0, newReg_.find('.'));
    TTAMachine::RegisterFile* rf =
        targetMachine().registerFileNavigator().item(rfName);
    int newRegIndex = atoi(newReg_.substr(newReg_.find('.')+1).c_str());
 
    // for writes.
    for (auto i: liveRange_->writes) {
        TTAProgram::Move& move = i->move();
        move.setDestination(new TTAProgram::TerminalRegister(
                                *rf->firstWritePort(), newRegIndex));
    }
 
    // for reads.
    for (auto i: liveRange_->reads) {
        TTAProgram::Move& move = i->move();
        move.setSource(new TTAProgram::TerminalRegister(
                           *rf->firstReadPort(), newRegIndex));
    }
 
    // for guards.
    for (auto i: liveRange_->guards) {
        TTAProgram::Move& move = i->move();
        setGuard(move, *rf, newRegIndex);
    }
}
 
void BFRenameLiveRange::setGuard(
    TTAProgram::Move& move, const TTAMachine::RegisterFile& rf, int regIndex){
 
    const TTAMachine::Guard& guard = move.guard().guard();
    TTAMachine::Bus* guardBus =  guard.parentBus();
    for (int j = 0 ; j < guardBus->guardCount(); j++) {
        TTAMachine::Guard *g = guardBus->guard(j);
        TTAMachine::RegisterGuard* rg =
            dynamic_cast<TTAMachine::RegisterGuard*>(g);
        if (rg) {
            if (rg->registerFile() == &rf &&
                rg->registerIndex() == regIndex &&
                rg->isInverted() == guard.isInverted()) {
                move.setGuard(new TTAProgram::MoveGuard(*g));
            }
        }
    }
}
 
void BFRenameLiveRange::undoSetTerminal() {
 
    // for writes.
    for (auto i: liveRange_->writes) {
        TTAProgram::Move& move = i->move();
        move.setDestination(oldReg_->copy());
    }
 
    // for reads.
    for (auto i: liveRange_->reads) {
        TTAProgram::Move& move = i->move();
        move.setSource(oldReg_->copy());
    }
 
    // for guards
    for (auto i: liveRange_->guards) {
        TTAProgram::Move& move = i->move();
        setGuard(move, oldReg_->registerFile(), oldReg_->index());
    }
 
}
 
void BFRenameLiveRange::undoOnlyMe() {
    // restore the DDG stage before the rename
    for (auto i: undoReadUpdateData_) {
        ddg().undo(i.second);
    }
    ddg().undo(undoWriteUpdateData_);
 
    undoSetTerminal();
 
    undoSetFirstDefsAndUses();
    undoSetRegDefsAndLastUses();
 
    unsetIncomingDeps();
    unsetOutgoingDeps();
 
    sched_.renamer()->revertedRenameToRegister(newReg_);
 
    undoNewAntiDeps();
 
}
 
void BFRenameLiveRange::undoNewAntiDeps() {
    for (auto e: createdAntidepEdges_) {
        ddg().removeEdge(*e);
    }
    createdAntidepEdges_.clear();
}
 
void BFRenameLiveRange::setIncomingDeps() {
    if (liveRange_->writes.size() != 1 ||
        !(*liveRange_->writes.begin())->move().isUnconditional()) {
        return;
    }
 
    oldKill_ = bb_->liveRangeData_->regKills_[newReg_].first;
    oldRegFirstDefines_ = bb_->liveRangeData_->regFirstDefines_[newReg_];
    oldRegFirstUses_ = bb_->liveRangeData_->regFirstUses_[newReg_];
}
void BFRenameLiveRange::unsetIncomingDeps() {
    bb_->liveRangeData_->regKills_[newReg_].first = oldKill_;
    bb_->liveRangeData_->regFirstDefines_[newReg_] = oldRegFirstDefines_;
    bb_->liveRangeData_->regFirstUses_[newReg_] = oldRegFirstUses_;
}
 
void BFRenameLiveRange::unsetOutgoingDeps() {
    bb_->liveRangeData_->regLastKills_[newReg_].first = oldLastKill_;
    bb_->liveRangeData_->regDefines_[newReg_] = oldRegDefines_;
}
 
void BFRenameLiveRange::setOutgoingDeps() {
    if (liveRange_->writes.size() != 1 ||
        !(*liveRange_->writes.begin())->move().isUnconditional()) {
        return;
    }
 
    oldLastKill_ = bb_->liveRangeData_->regLastKills_[newReg_].first;
    oldRegDefines_ = bb_->liveRangeData_->regDefines_[newReg_];
 
    bb_->liveRangeData_->regLastKills_[newReg_].first =
        MoveNodeUse(**liveRange_->writes.begin());
    bb_->liveRangeData_->regDefines_[newReg_].clear();
}
 
 
void BFRenameLiveRange::setRegDefsAndLastUses() {
    // for writing.
    for (auto i: liveRange_->writes) {
        MoveNodeUse mnd(*i);
        bb_->liveRangeData_->regDefines_[newReg_].insert(mnd);
    }
 
    // for reading.
    for (auto i: liveRange_->reads) {
        MoveNodeUse mnd(*i);
        bb_->liveRangeData_->regLastUses_[newReg_].insert(mnd);
    }
 
    // for reading.
    for (auto i: liveRange_->guards) {
        MoveNodeUse mnd(*i, true);
        bb_->liveRangeData_->regLastUses_[newReg_].insert(mnd);
    }
 
}
 
void BFRenameLiveRange::undoSetRegDefsAndLastUses() {
    // for writing.
    for (auto i: liveRange_->writes) {
        MoveNodeUse mnd(*i);
        bb_->liveRangeData_->regDefines_[newReg_].erase(mnd);
    }
 
    // for reading.
    for (auto i: liveRange_->reads) {
        MoveNodeUse mnd(*i);
        bb_->liveRangeData_->regLastUses_[newReg_].erase(mnd);
    }
 
    // for reading.
    for (auto i: liveRange_->guards) {
        MoveNodeUse mnd(*i, true);
        bb_->liveRangeData_->regLastUses_[newReg_].erase(mnd);
    }
}
 
void BFRenameLiveRange::setFirstDefsAndUses() {
 
    // for writing.
    for (auto i: liveRange_->writes) {
        MoveNodeUse mnd(*i);
        bb_->liveRangeData_->regFirstDefines_[newReg_].insert(mnd);
        // TODO: only if intra-bb-antideps enabled?
//        static_cast<DataDependenceGraph*>(ddg().rootGraph())->
//            updateRegWrite(mnd, newReg, *bb_);
    }
 
    // for reading.
    for (auto i: liveRange_->reads) {
        MoveNodeUse mnd(*i);
        bb_->liveRangeData_->regFirstUses_[newReg_].insert(mnd);
        // no need to create raw deps here
    }
 
    // for guards.
    for (auto i: liveRange_->guards) {
        MoveNodeUse mnd(*i, true);
        bb_->liveRangeData_->regFirstUses_[newReg_].insert(mnd);
        // no need to create raw deps here
    }
}
 
void BFRenameLiveRange::undoSetFirstDefsAndUses() {
 
    // for writing.
    for (auto i: liveRange_->writes) {
        MoveNodeUse mnd(*i);
        bb_->liveRangeData_->regFirstDefines_[newReg_].erase(mnd);
 
 
        // TODO: only if intra-bb-antideps enabled?
//        static_cast<DataDependenceGraph*>(ddg().rootGraph())->
//            updateRegWrite(mnd, newReg, *bb_);
    }
 
    // for reading.
    for (auto i: liveRange_->reads) {
        MoveNodeUse mnd(*i);
        bb_->liveRangeData_->regFirstUses_[newReg_].erase(mnd);
    }
 
    // for guards.
    for (auto i: liveRange_->guards) {
        MoveNodeUse mnd(*i, true);
        bb_->liveRangeData_->regFirstUses_[newReg_].erase(mnd);
    }
}
 
 
 
 
 
bool BFRenameLiveRange::renameLiveRange(
    LiveRange& liveRange, const TCEString& newReg, bool usedAfter) {
 
    bool usedBefore = false;
 
    newReg_ = newReg;
    oldReg_ = (*liveRange.writes.begin())->move().destination().copy();
 
    assert(newReg.length() > 2);
 
    if (usedAfter) {
        TCEString rfName = newReg_.substr(0, newReg_.find('.'));
        TTAMachine::RegisterFile* rf =
            targetMachine().registerFileNavigator().item(rfName);
        int newRegIndex = atoi(newReg_.substr(newReg_.find('.')+1).c_str());
        DataDependenceGraph::NodeSet firstWrites =
            ddg().firstScheduledRegisterWrites(*rf, newRegIndex);
 
        // make sure no circular antidep path
        for (auto j: firstWrites) {
            for (auto i: liveRange.reads) {
                if (ddg().hasPath(*j, *i)) {
                    return false;
                }
            }
 
            for (auto i: liveRange.writes) {
                if (ddg().hasPath(*j, *i)) {
                    return false;
                }
            }
        }
 
        // antideps
        for (auto j: firstWrites) {
            for (auto i: liveRange.writes) {
                DataDependenceEdge* newWAW =
                    new DataDependenceEdge(
                        DataDependenceEdge::EDGE_REGISTER,
                        DataDependenceEdge::DEP_WAW, newReg);
                ddg().connectNodes(*i,*j, *newWAW);
                createdAntidepEdges_.insert(newWAW);
            }
 
            for (auto i: liveRange.reads) {
                DataDependenceEdge* newWAR =
                    new DataDependenceEdge(
                        DataDependenceEdge::EDGE_REGISTER,
                        DataDependenceEdge::DEP_WAR, newReg);
                ddg().connectNodes(*i,*j, *newWAR);
                createdAntidepEdges_.insert(newWAR);
            }
        }
    } else {
        setOutgoingDeps();
        setRegDefsAndLastUses();
 
 
// TODO
#if 0
        // need to create backedges to first if we are loop scheduling.
        if (loopScheduling) {
            updateAntiEdgesFromLRTo(liveRange, newReg, bb_, 1);
        }
#endif
    }
 
    if (usedBefore) {
        return false;
    } else {
        setIncomingDeps();
        setFirstDefsAndUses();
    }
 
    setTerminals();
    notifySelector();
 
    // for writes.
    assert (liveRange_->writes.size() == 1);
    for (auto i: liveRange_->writes) {
        undoWriteUpdateData_ = ddg().destRenamed(*i);
    }
 
    // for reads
    for (auto i: liveRange_->reads) {
        undoReadUpdateData_[i] = ddg().sourceRenamed(*i);
    }
 
    assert(liveRange_->guards.size() == 0);
    // for guards
    for (auto i: liveRange_->guards) {
        undoReadUpdateData_[i] = ddg().guardRenamed(*i);
    }
 
    sched_.renamer()->renamedToRegister(newReg);
    notifySelector();
    return true;
}
 
 
void BFRenameLiveRange::notifySelector() {
    // then update ddg and notify selector.
 
    // for writes.
    for (auto i: liveRange_->writes) {
        DataDependenceGraph::NodeSet writeSuccessors =
            ddg().successors(*i);
        DataDependenceGraph::NodeSet writePredecessors =
            ddg().predecessors(*i);
 
        // notify successors of write to prevent orphan nodes.
        for (auto j: writeSuccessors) {
            sched_.currentFront()->mightBeReady(*j);
        }
 
        // notify successors of write to prevent orphan nodes.
        for (auto j: writePredecessors) {
            sched_.currentFront()->mightBeReady(*j);
        }
 
    }
 
    // for reads
    for (auto i: liveRange_->reads) {
        DataDependenceGraph::NodeSet successors =
            ddg().successors(*i);
        DataDependenceGraph::NodeSet predecessors =
            ddg().predecessors(*i);
 
        // notify successors to prevent orphan nodes.
        for (auto j: successors) {
            sched_.currentFront()->mightBeReady(*j);
        }
 
        // notify successors to prevent orphan nodes.
        for (auto j: predecessors) {
            sched_.currentFront()->mightBeReady(*j);
        }
    }
 
    // for guards
    for (auto i: liveRange_->guards) {
        DataDependenceGraph::NodeSet successors =
            ddg().successors(*i);
        DataDependenceGraph::NodeSet predecessors =
            ddg().predecessors(*i);
 
        // notify successors to prevent orphan nodes.
        for (auto j: successors) {
            sched_.currentFront()->mightBeReady(*j);
        }
 
        // notify successors to prevent orphan nodes.
        for (auto j: predecessors) {
            sched_.currentFront()->mightBeReady(*j);
        }
    }
}
 
BFRenameLiveRange::~BFRenameLiveRange() {
    delete oldReg_;
}