MachineAnalysis.cc

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/*
    Copyright (c) 2002-2009 Tampere University.
 
    This file is part of TTA-Based Codesign Environment (TCE).
 
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/**
 * @file MachineAnalysis.cc
 *
 * Implementation of MachineAnalysis class.
 *
 * @author Heikki Kultala 2008 (heikki.kultala-no.spam-tut.fi)
 * @note rating: red
 */
 
#include "MachineAnalysis.hh"
#include "Machine.hh"
 
#include "MachineConnectivityCheck.hh"
 
#include <cmath>
 
//#define DEBUG_MACHINE_ANALYSIS
 
/**
 * Constructor.
 * @param machine to analyse.
 */
MachineAnalysis::MachineAnalysis(const TTAMachine::Machine& machine) {
 
    // do heurictics for FU's
 
    TTAMachine::Machine::FunctionUnitNavigator fuNav = 
        machine.functionUnitNavigator();
 
    // todo: better heuristics here, based on available operations etc.
    fuILP_ = fuNav.count() * 0.55;
 
    // Connectivity heuristics
 
    int fuPortConnecteds = 0;
    int fuPortUnconnecteds = 0;
 
    for (int i = 0; i < fuNav.count(); i++) {
        TTAMachine::FunctionUnit& fu1 = *fuNav.item(i);
        for (int j = 0; j < fu1.portCount(); j++ ) {
            TTAMachine::Port& port1 = *fu1.port(j);
            if (port1.inputSocket() != NULL) {
                for (int k = 0; k < fuNav.count(); k++) {
                    TTAMachine::FunctionUnit& fu2 = *fuNav.item(k);
                    for (int l = 0; l < fu2.portCount(); l++ ) {
                        TTAMachine::Port& port2 = *fu2.port(l);
                        if (port2.outputSocket() != NULL) {
                            if (MachineConnectivityCheck::isConnected(
                                    port2,port1)) {
                                fuPortConnecteds++;
                            } else {
                                fuPortUnconnecteds++;
                            }
                        }
                    }
                }
            }
        }
    }
        
    bypassability_ = fuPortConnecteds/
        float(fuPortConnecteds+fuPortUnconnecteds);
 
    TTAMachine::Machine::RegisterFileNavigator regNav =
        machine.registerFileNavigator();
    int rfCount = regNav.count();
 
    TTAMachine::Machine::BusNavigator busNav =
        machine.busNavigator();
 
    int rfFuConnecteds = 0;
    int rfFuUnconnecteds = 0;
 
    for (int i = 0; i < fuNav.count(); i++) {
        TTAMachine::FunctionUnit& fu1 = *fuNav.item(i);
        for (int j = 0; j < fu1.portCount(); j++ ) {
            TTAMachine::Port& port = *fu1.port(j);
            if (port.inputSocket() != NULL) {
                for (int i = 0; i < rfCount; i++) {
                    TTAMachine::RegisterFile& rf = *regNav.item(i);
                    if (MachineConnectivityCheck::isConnected(rf, port)) {
                        rfFuConnecteds++;
                    } else {
                        rfFuUnconnecteds++;
                    }
                }
            }
 
            if (port.outputSocket() != NULL) {
                for (int i = 0; i < rfCount; i++) {
                    TTAMachine::RegisterFile& rf = *regNav.item(i);
                    if (MachineConnectivityCheck::isConnected(port,rf)) {
                        rfFuConnecteds++;
                    } else {
                        rfFuUnconnecteds++;
                    }
                }
            }
        }
    }
 
    // do heuristics for RF's
    
    int rfWritePorts = 0;
    int rfReadPorts = 0;
    for (int i = 0; i < rfCount; i++) {
        TTAMachine::RegisterFile& rf = *regNav.item(i);
        for (int j = 0; j < rf.portCount(); j++) {
            const TTAMachine::Port& port = *rf.port(j);
            if (port.outputSocket() != NULL) {
                rfReadPorts++;
            }
            if (port.inputSocket() != NULL) {
                rfWritePorts++;
            }
        }
    }
    
    // rfILP comes from all RF's with 
    float avgRfWrites = float(rfWritePorts)/pow(rfCount,0.5);
    float avgRfReads = float(rfReadPorts)/pow(rfCount,0.5);
    float bypassedRfReadILP = avgRfReads/(1.17-(0.56*bypassability_));
    float bypassedRfWriteILP = avgRfWrites/(0.83-(0.415*bypassability_));
    float rfReadILP = avgRfReads/1.17;
    float rfWriteILP = avgRfWrites/0.83;
 
    // todo: fuzzier heuristic
    rfILP_ = std::min(rfReadILP, rfWriteILP);
    bypassedRfILP_ = std::min(bypassedRfReadILP, bypassedRfWriteILP);
 
    connectivity_ = rfFuConnecteds/
        float(rfFuConnecteds+rfFuUnconnecteds);
    float transfers = connectivity_* busNav.count();
    
    busILP_ = transfers / (2.5-(0.415*bypassability_));
 
    // take the final value by inverse of pythagoral of inverses
    averageILP_ = pow((pow(busILP_,-2)+
                       pow(bypassedRfILP_,-2)+
                       pow(fuILP_,-2)), -0.5);
 
    // then calculate guardability.
 
    float guardedBuses = 0;
    for (int i = 0; i < busNav.count(); i++) {
        TTAMachine::Bus& bus = *busNav.item(i);
        if (bus.guardCount() > 0) {
            guardedBuses++;
        }
    }
    guardability_ = busNav.count() / guardedBuses;
 
#ifdef DEBUG_MACHINE_ANALYSIS
    std::cout << "Machine analysis done.." << std::endl;
    std::cout << "\tbypassability: " << bypassability_ << std::endl;
    std::cout << "\tconnectivity: " << connectivity_ << std::endl;
    std::cout << "\tguardability: " << guardability_ << std::endl;
    std::cout << "\tRF ilp: " << rfILP_ << std::endl;
    std::cout << "\t\tread ilp: " << rfReadILP << std::endl;
    std::cout << "\t\twrite ilp: " << rfWriteILP << std::endl;
    std::cout << "\tbypassd rf ilp: " << bypassedRfILP_ << std::endl;
    std::cout << "\tbus ilp: " << busILP_ << std::endl;
    std::cout << "\tfu ilp: " << fuILP_ << std::endl;
    std::cout << "total ilp: " << averageILP_ << std::endl;
#endif
 
}