BFPostpassBypass.cc

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/*
    Copyright (c) 2002-2014 Tampere University.
 
    This file is part of TTA-Based Codesign Environment (TCE).
 
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/**
 * @file BFPostpassBypass.cc
 *
 * Definition of BFPostpassBypass class
 *
 * Performs a bypass after scheduling everything.
 * May also bypass over a loop edge.
 *
 * @author Heikki Kultala 2014-2020(heikki.kultala-no.spam-tuni.fi)
 * @note rating: red
 */
 
#include "DataDependenceGraph.hh"
#include "BFPostpassBypass.hh"
#include "BFUnscheduleMove.hh"
#include "BFScheduleExact.hh"
#include "Move.hh"
#include "BFScheduleBU.hh"
#include "Terminal.hh"
#include "BFPostpassDRE.hh"
#include "BFUnscheduleFromBody.hh"
#include "BFAssignToBody.hh"
#include "BFPostpassLoopDRE.hh"
#include "MoveNodeDuplicator.hh"
#include "BFMergeAndKeepUser.hh"
 
bool BFPostpassBypass::operator()() {
 
 
    assert(dst_.isScheduled());
    assert(src_.isScheduled());
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
    static int counter = 0;
    static int counter2 = 0;
#endif
 
    int originalCycle = dst_.cycle();
    int srcCycle = src_.cycle();
 
    if (loopBypass_ && originalCycle >= (int)ii()) {
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
        std::cerr << "too late cycle for loop bypass" << std::endl;
#endif
        return false;
    }
 
    const TTAMachine::FunctionUnit* ssfu = src_.isSourceOperation() ?
        &src_.move().source().functionUnit() : nullptr;
 
    const TTAMachine::FunctionUnit* ddfu = dst_.isDestinationOperation() ?
        &dst_.move().destination().functionUnit() : nullptr;
 
    if (!loopBypass_) {
        runPreChild(new BFUnscheduleMove(sched_, dst_));
    } else {
        runPreChild(new BFUnscheduleFromBody(sched_, dst_));
    }
    runPreChild(new BFUnscheduleMove(sched_, src_));
 
    if (!runPreChild(
            new BFMergeAndKeepUser(sched_, src_, dst_, loopBypass_))) {
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
        std::cerr << "merge and keep fail." << src_.toString()
                  << " and " << dst_.toString() << std::endl;
#endif
        undoAndRemovePreChildren();
        return false;
    }
 
    dred_ = runPostChild(new BFPostpassDRE(sched_, src_));
 
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
    std::cerr << "\t\t\tTried ordinary dre: " << dred_ << std::endl;
#endif
    if (loopBypass_ && !dred_) {
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
        std::cerr << "\t\t\tsrccycle: " << srcCycle << std::endl;
#endif
        if (srcCycle >= (int)ii()) {
            dred_ = runPostChild(
                new BFPostpassLoopDRE(sched_, src_, srcCycle));
        } else {
            if (ddg().latestCycle(src_) >= (signed)ii()) {
                dred_ = runPostChild(
                    new BFPostpassLoopDRE(sched_, src_, ii()));
            }
        }
    }
 
    // TODO: try to DRE here
 
    if (!dred_) {
        // if returning the old fails, abort everything
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
        std::cerr << "\t\t\tundoing unscheduling of src" << std::endl;
#endif
        // if not dre, return the result
        if (!runPostChild(
                new BFScheduleExact(sched_, src_, srcCycle, false, ssfu))) {
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
            std::cerr << "Scheduling back src:" << src_.toString()
                      << " to cycle: " << srcCycle
                      << " after post-pass bypass move failed" << std::endl;
            ddg().writeToDotFile("postpass_fail1.dot");
#endif
            undo();
            return false;
        }
 
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
        std::cerr << "\t\t\tundid unscheduling of src" << std::endl;
#endif
    }
 
    BFOptimization* schedDst = NULL;
    if (dst_.move().isControlFlowMove() ||
        (ii() != 0 &&
         static_cast<DataDependenceGraph*>(ddg().rootGraph())->
         writesJumpGuard(dst_))) {
        if (!loopBypass_) {
            schedDst = new BFScheduleExact(
                sched_, dst_, originalCycle, false);
        } else {
            schedDst = new BFAssignToBody(
                sched_, dst_, originalCycle, ssfu, ddfu);
        }
    } else {
        if (!loopBypass_) {
            schedDst = new BFScheduleExact(
                sched_, dst_, originalCycle, false);
        } else {
            schedDst = new BFAssignToBody(
                sched_, dst_, originalCycle, ssfu, ddfu);
        }
    }
 
    if (!runPostChild(schedDst)) {
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
        std::cerr << "\t\tScheduling post-pass bypassed move failed:"
                  <<  dst_.toString() << "cycle: " << originalCycle
                  << std::endl;
        ddg().writeToDotFile("postpass_fail2.dot");
#endif
        undo();
        return false;
    }
    return true;
}
 
void BFPostpassBypass::undoOnlyMe() {
 
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
    std::cerr << "isloopbypass?" << loopBypass_ << std::endl;
    std::cerr << "\t\t\tPerforming unmerge user of: "
              << src_.toString() << " and: " << dst_.toString()
              << std::endl;
#endif
#ifdef DEBUG_BUBBLEFISH_SCHEDULER
    std::cerr << "\t\t\tPerformed unmerge user of: "
              << src_.toString() << " and: " << dst_.toString()
              << std::endl;
#endif
}