ControlUnit.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 ControlUnit.cc
 *
 * Implementation of ControlUnit class.
 *
 * @author Lasse Laasonen 2004 (lasse.laasonen-no.spam-tut.fi)
 * @author Pekka J��skel�inen 2006 (pekka.jaaskelainen-no.spam-tut.fi)
 */
 
#include "ControlUnit.hh"
#include "SpecialRegisterPort.hh"
#include "Guard.hh"
#include "MOMTextGenerator.hh"
#include "Application.hh"
#include "Machine.hh"
#include "ObjectState.hh"
#include "Conversion.hh"
 
using std::string;
 
namespace TTAMachine {
 
// initialization of static data members
const string ControlUnit::OSNAME_CONTROL_UNIT = "control_unit";
const string ControlUnit::OSKEY_DELAY_SLOTS = "d_slots";
const string ControlUnit::OSKEY_GUARD_LATENCY = "g_latency";
const string ControlUnit::OSKEY_RA_PORT = "ra_port";
 
/**
 * Constructor.
 *
 * @param name Name of the control unit.
 * @param delaySlots Number of delay instruction slots of the transport pipeline.
 * @param globalGuardLatency The global guard latency.
 * @exception OutOfRange If some of the given values is out of valid range.
 * @exception InvalidName If the given name is not a valid component name.
 */
ControlUnit::ControlUnit(
    const string& name, int delaySlots, int globalGuardLatency)
    : FunctionUnit(name),
      delaySlots_(delaySlots),
      globalGuardLatency_(0),
      raPort_(NULL) {
    setDelaySlots(delaySlots);
    setGlobalGuardLatency(globalGuardLatency);
}
 
/**
 * Constructor.
 *
 * Loads the state of the control unit from the given ObjectState instance.
 * Does not load references to other components.
 *
 * @param state The ObjectState instance from which the name is taken.
 * @exception ObjectStateLoadingException If the given ObjectState instance
 *                                        is invalid.
 */
ControlUnit::ControlUnit(const ObjectState* state)
    : FunctionUnit(state),
      delaySlots_(0),
      globalGuardLatency_(0),
      raPort_(NULL) {
    loadStateWithoutReferences(state);
}
 
/**
 * Destructor.
 */
ControlUnit::~ControlUnit() {
    unsetMachine();
}
 
 
/**
 * Copies the instance.
 *
 * Current FunctionUnit state is copied to a new FunctionUnit object.
 *
 * @return Copy of the instance.
 */
ControlUnit*
ControlUnit::copy() const {
 
    return new ControlUnit(saveState());
}
 
 
/**
 * Attaches the control unit to machine.
 *
 * @param mach The machine.
 * @exception ComponentAlreadyExists If the given machine already has a
 *                                   global control unit.
 */
void
ControlUnit::setMachine(Machine& mach) {
    // if global guard latency is zero, there cannot be a register guard
    // that reads a register of local guard latency zero
    if (globalGuardLatency() == 0 && hasLocalGuardLatencyOfZero(mach)) {
        setGlobalGuardLatency(1);
    }   
 
    internalSetMachine(mach);
    mach.setGlobalControl(*this);
}
 
/**
 * Detaches the control unit from machine.
 */
void
ControlUnit::unsetMachine() {
    if (!isRegistered()) {
        return;
    } else {
        Machine* mach = machine();
        unsetMachineDerived();
        mach->unsetGlobalControl();
    }
}
 
void
ControlUnit::setDelaySlots(int delaySlots) {
    if (delaySlots < 0) {
        throw OutOfRange(__FILE__, __LINE__, __func__);
    }
    delaySlots_ = delaySlots;
}
 
/**
 * Sets the global guard latency.
 *
 * @param latency The new latency.
 * @exception OutOfRange If the given latency is negative.
 */
void
ControlUnit::setGlobalGuardLatency(int latency) {
    if (latency < 0) {
        throw OutOfRange(__FILE__, __LINE__, __func__);
    }
 
    // if latency is zero, there must not be a guard term that reads a 
    // registr of a register file with local guard latency of zero
    if (latency == 0 && isRegistered()) {
        if (hasLocalGuardLatencyOfZero(*machine())) {
            MOMTextGenerator textGen;
            boost::format text = textGen.text(
                MOMTextGenerator::TXT_INVALID_GUARD_LATENCY);
            throw OutOfRange(
                __FILE__, __LINE__, __func__, text.str());
        }
    }
 
    globalGuardLatency_ = latency;
}
 
/**
 * Returns the number of special register ports in the control unit.
 *
 * @return The number of special register ports.
 */
int
ControlUnit::specialRegisterPortCount() const {
    return portCount() - operationPortCount();
}
 
 
/**
 * Tells whether the control unit has a special register port of the given
 * name.
 *
 * @return True if the control unit has the port, otherwise false.
 */
bool
ControlUnit::hasSpecialRegisterPort(const std::string& name) const {
    return hasPort(name) && !hasOperationPort(name);
}
 
 
/**
 * Returns a special register port by the given index.
 *
 * @param index The index.
 * @return A special register port.
 * @exception OutOfRange If the given index is less than 0 or greater or
 *                       equal to the number of special register ports.
 */
SpecialRegisterPort*
ControlUnit::specialRegisterPort(int index) const {
    const string procName = "ControlUnit::specialRegisterPort";
 
    if (index < 0) {
        throw OutOfRange(__FILE__, __LINE__, procName);
    }
 
    int portCount = this->portCount();
    int srPortCount(-1);
 
    for (int i = 0; i < portCount; i++) {
        BaseFUPort* port = this->port(i);
        SpecialRegisterPort* srPort =
            dynamic_cast<SpecialRegisterPort*>(port);
        if (srPort != NULL) {
            srPortCount++;
            if (srPortCount == index) {
                return srPort;
            }
        }
    }
 
    throw OutOfRange(__FILE__, __LINE__, procName);
}
 
/**
 * Returns a special register port by the given name.
 *
 * @param name Name of the port.
 * @return A special register port.
 * @exception InstanceNotFound If a special register port does not exist by
 *                             the given name.
 */
SpecialRegisterPort*
ControlUnit::specialRegisterPort(const std::string& name) const {
    const string procName = "ControlUnit::specialRegisterPort";
 
    if (!hasPort(name)) {
        throw InstanceNotFound(
            __FILE__, __LINE__, procName, "Port not found: " + name);
    }
 
    Port* port = this->port(name);
    SpecialRegisterPort* srPort = dynamic_cast<SpecialRegisterPort*>(port);
    if (srPort == NULL) {
        throw InstanceNotFound(__FILE__, __LINE__, procName);
    }
    return srPort;
}
 
/**
 * Binds the given port to return address port.
 *
 * If there is another port bound to return address port already, unbinds it.
 *
 * @param port The port to be bound.
 * @exception IllegalRegistration If the given port is not a port of this
 *                                control unit.
 */
void
ControlUnit::setReturnAddressPort(const SpecialRegisterPort& port) {
    if (port.parentUnit() != this) {
        const string procName = "ControlUnit::setReturnAddressPort";
        throw IllegalRegistration(__FILE__, __LINE__, procName);
    }
 
    raPort_ = const_cast<SpecialRegisterPort*>(&port);
}
 
/**
 * Unbinds the return address port if one exists.
 */
void
ControlUnit::unsetReturnAddressPort() {
    raPort_ = NULL;
}
 
 
/**
 * Tells whether the control unit has a return address port.
 *
 * @return True if a return address port exists, otherwise false.
 */
bool
ControlUnit::hasReturnAddressPort() const {
    return raPort_ != NULL;
}
 
 
/**
 * Returns the return address port.
 *
 * @return The return address port.
 * @exception InstanceNotFound If there is no return address port.
 */
SpecialRegisterPort*
ControlUnit::returnAddressPort() const {
    if (raPort_ != NULL) {
        return raPort_;
    } else {
        const string procName = "ControlUnit::returnAddressPort";
        throw InstanceNotFound(__FILE__, __LINE__, procName);
    }
}
 
/**
 * Saves the contents to an ObjectState tree.
 *
 * @return The newly created ObjectState tree.
 */
ObjectState*
ControlUnit::saveState() const {
 
    ObjectState* cUnit = FunctionUnit::saveState();
    cUnit->setName(OSNAME_CONTROL_UNIT);
 
    // set delay slots
    cUnit->setAttribute(OSKEY_DELAY_SLOTS, delaySlots_);
 
    // set global guard latency
    cUnit->setAttribute(OSKEY_GUARD_LATENCY, globalGuardLatency_);
 
    // set return address port
    if (hasReturnAddressPort()) {
        cUnit->setAttribute(OSKEY_RA_PORT, returnAddressPort()->name());
    }
 
    return cUnit;
}
 
 
/**
 * Loads its state from the given ObjectState instance.
 *
 * @param state The ObjectState instance.
 * @exception ObjectStateLoadingException If the given ObjectState instance
 *                                        invalid or if connections to other
 *                                        machine parts cannot be made.
 */
void
ControlUnit::loadState(const ObjectState* state) {
    FunctionUnit::loadState(state);
    loadStateWithoutReferences(state);
}
 
/**
 * Removes the given port from the control unit and unsets the binding of
 * return address port if necessary.
 *
 * @param port The port to be removed.
 */
void
ControlUnit::removePort(Port& port) {
    if (&port == raPort_) {
        unsetReturnAddressPort();
    }
    FunctionUnit::removePort(port);
}
 
 
/**
 * Loads the state of the control unit without references to other
 * components.
 *
 * @param state The ObjectState instance from which the state is loaded.
 * @exception ObjectStateLoadingException If an error occurs while loading
 *                                        the state.
 */
void
ControlUnit::loadStateWithoutReferences(const ObjectState* state) {
    const string procName = "ControlUnit::loadStateWithoutReferences";
 
    if (state->name() != OSNAME_CONTROL_UNIT) {
        throw ObjectStateLoadingException(__FILE__, __LINE__, procName);
    }
 
    try {
        setDelaySlots(state->intAttribute(OSKEY_DELAY_SLOTS));
        setGlobalGuardLatency(state->intAttribute(OSKEY_GUARD_LATENCY));
        if (state->hasAttribute(OSKEY_RA_PORT)) {
            string portName = state->stringAttribute(OSKEY_RA_PORT);
            setReturnAddressPort(*specialRegisterPort(portName));
        } else {
            unsetReturnAddressPort();
        }
 
    } catch (Exception& e) {
        throw ObjectStateLoadingException(__FILE__, __LINE__, procName,
                                          e.errorMessage());
    }
}
 
/**
 * Tells whether the given machine has a guard that reads a register with
 * local guard latency of zero.
 *
 * @param machine The machine.
 * @return True if the machine has the guard, otherwise false.
 */
bool
ControlUnit::hasLocalGuardLatencyOfZero(const Machine& machine) {
    Machine::BusNavigator busNav = machine.busNavigator();
    for (int i = 0; i < busNav.count(); i++) {
        Bus* bus = busNav.item(i);
        for (int i = 0; i < bus->guardCount(); i++) {
            Guard* guard = bus->guard(i);
            RegisterGuard* regGuard = 
                dynamic_cast<RegisterGuard*>(guard);
            if (regGuard != NULL) {
                const RegisterFile* rf = regGuard->registerFile();
                if (rf->guardLatency() == 0) {
                    return true;
                }
            }
        }
    }
    return false;
}
}