BFPushAntidepDown.cc

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/*
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/**
 * @file BFPushAntidepDown.cc
 *
 * Definition of BFPushAntidepDown class.
 *
 * Tries to reschedule a move into later cycle to allow move which has an
 * antidep to it to be scheduler later.
 *
 * @author Heikki Kultala 2014-2020(heikki.kultala-no.spam-tuni.fi)
 * @note rating: red
 */
 
#include "BFPushAntidepDown.hh"
 
#include "DataDependenceGraph.hh"
#include "SimpleResourceManager.hh"
#include "MoveNode.hh"
#include "Move.hh"
#include "Bus.hh"
 
#include "BF2Scheduler.hh"
#include "MoveNodeDuplicator.hh"
#include "UniversalMachine.hh"
 
//#define DEBUG_BUBBLEFISH_SCHEDULER
 
bool
BFPushAntidepDown::operator()() {
    if (mn_.move().isControlFlowMove()) {
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
        std::cerr << "\t\t\tCannot reschedule control flow move!" << std::endl;
#endif
        return false;
    }
 
    if (&mn_ == sched_.guardWriteNode()) {
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
        std::cerr << "\t\t|TCannot reschedule guard write move!" << std::endl;
#endif
        return false;
    }
 
    unscheduleOriginal();
 
    int ddgLC = ddg().latestCycle(mn_);
    int ddgEC = ddg().earliestCycle(mn_);
 
    // first try to schedule top-down close to the optimal as possible
    int prefEc = newLC_ - lat_ +1;
    if (ddgEC > prefEc) {
        prefEc = ddgEC;
    }
 
    int ec = rmEC(prefEc, mn_);
    if (ec <= std::min(ddgLC,sched_.maximumAllowedCycle()) && ec != -1) {
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
    std::cerr << "\t\t\t\t\ttopdown resched: " << ec << std::endl;
#endif
    assign(ec, mn_);
    return true;
    } else {
    // topdown failed, bottom-up then be it
    int lc = rmLC(
        (std::min(ddgLC, sched_.maximumAllowedCycle())),mn_);
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
    std::cerr << "\t\t\t\tbottomup resched ddglc: " << ddgLC << " latest_: "
              << sched_.maximumAllowedCycle() << " lc: " << lc << std::endl;
#endif
    if (lc < ddgEC || lc == oldCycle_) {
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
        std::cerr << "\t\tPushing down antidep dest: " << mn_.toString()
                  << " failed lc: "<< lc << " ddgEC: " << ddgEC << std::endl;
        std::cerr << "\t\tPushAntidepsDown seting to old bus: "
                  << mn_.toString() << " to bus "
                  << oldBus_->name() << std::endl;
#endif
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
        assert(canAssign(oldCycle_, mn_, oldBus_, NULL, NULL, prologBus_));
#endif
        assign(oldCycle_, mn_, oldBus_, NULL, NULL, prologBus_,
               oldImmWriteCycle_, prologImmWriteCycle_);
        return false;
    }
    assert(lc != -1);
    assign(lc, mn_);
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
    std::cerr << "\t\tPushed antidep down: " << mn_.toString() << " bus: "
              << mn_.move().bus().name() << std::endl;
#endif
    return true;
    }
    return false;
}