ScheduleEstimator.cc

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/*
    Copyright (c) 2002-2013 Tampere University.
 
    This file is part of TTA-Based Codesign Environment (TCE).
 
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/**
 * @file ScheduleEstimator.cc
 *
 * Definition of ScheduleEstimator class.
 *
 * This class tries to estimate the worst possible cycle count
 * for a basic block.
 *
 * @author Heikki Kultala 2019 (hkultala-no.spam-tuni.fi)
 * @note rating: red
 */
 
#include "ScheduleEstimator.hh"
#include "BasicBlock.hh"
#include "MachineConnectivityCheck.hh"
#include "Instruction.hh"
#include "Move.hh"
#include "Terminal.hh"
#include "Machine.hh"
#include "ControlUnit.hh"
#include "MachineInfo.hh"
#include "Operation.hh"
#include "ControlFlowGraph.hh"
 
int
ScheduleEstimator::maximumSizeOfBB(
    TTAProgram::BasicBlock& bb, const TTAMachine::Machine& mach) {
 
    auto tempRegFiles = MachineConnectivityCheck::tempRegisterFiles(mach);
    int tempRegCount = tempRegFiles.size();
 
    int size = 0;
    int iCount = bb.instructionCount();
 
    for (int i = 0; i < iCount; i++) {
        auto& ins = bb[i];
        for (int j = 0; j < ins.moveCount(); j++) {
            size++;
            // temp reg copies may make schedule longer.
            size += tempRegCount;
            auto& m = ins.move(j);
            auto& src = m.source();
 
            if (m.isControlFlowMove()) {
                size += mach.controlUnit()->delaySlots() + 1;
            }
            if (src.isFUPort() && !src.isRA()) {
                const Operation& o = src.hintOperation();
                TCEString opName = o.name();
                int lat = MachineInfo::maxLatency(mach,opName);
                if (lat > 0) {
                    size += lat-1;
                }
            }
        }
    }
    return size;
}
 
 
void
ScheduleEstimator::handleControlFlowGraph(
    ControlFlowGraph& cfg, const TTAMachine::Machine& mach) {
 
    for (int bbIndex = 0; bbIndex < cfg.nodeCount(); ++bbIndex) {
        BasicBlockNode& bbn = cfg.node(bbIndex);
        if (!bbn.isNormalBB()) {
            bbn.setMaximumSize(0);
        } else {
            auto& bb = bbn.basicBlock();
            bbn.setMaximumSize(
                bbn.isScheduled() ?
                bb.instructionCount() - bb.skippedFirstInstructions() :
                maximumSizeOfBB(bb, mach));
        }
    }
}