OperationContextPimpl.cc

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/*
    Copyright (c) 2002-2009 Tampere University.
 
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/**
 * @file OperationContextPimpl.cc
 *
 * Definition of OperationContextPimpl (private implementation) class.
 *
 * @author Viljami Korhonen 2008 (viljami.korhonen-no.spam-tut.fi)
 * @note rating: red
 */
 
#include "OperationContextPimpl.hh"
#include "OperationContext.hh"
#include "Application.hh"
#include "Memory.hh"
#include "OperationState.hh"
#include "SimValue.hh"
#include "OperationContextPimpl.hh"
#include "Exception.hh"
#include <string>
 
using std::string;
 
/// Id given for the next created OperationContext instance.
int OperationContextPimpl::nextContextId_ = 0;
 
InstructionAddress dummyInstructionAddress;
int dummyInt;
 
/**
 * Constructor for contexts suitable for basic operations.
 */
OperationContextPimpl::OperationContextPimpl(const TCEString& name) : 
    memory_(NULL), 
    programCounter_(dummyInstructionAddress), 
    returnAddress_(NullSimValue::instance()),
    saveReturnAddress_(false),
    updateProgramCounter_(false),
    cycleCount_(0),
    cycleCountVar_(NULL),
    FUName_(name),
    branchDelayCycles_(dummyInt) {
    initializeContextId();
    stateRegistry_ = new StateRegistry();
}
 
/**
 * Constructor for contexts suitable for any kinds of operations.
 *
 * @param memory The memory model instance.
 * @param nww The natural word width of the memory model.
 * @param programCounter The program counter register.
 * @param returnAddress The return address register.
 * @param syscallHandler The syscall handler register.
 * @param syscallNumber The syscall code register.
 *
 */
OperationContextPimpl::OperationContextPimpl(
    const TCEString& name,
    Memory* memory,
    InstructionAddress& programCounter,
    SimValue& returnAddress,
    int delayCycles) :
    memory_(memory),
    programCounter_(programCounter),
    returnAddress_(returnAddress),
    saveReturnAddress_(false),
    updateProgramCounter_(false),
    cycleCount_(0),
    cycleCountVar_(NULL),
    FUName_(name),
    branchDelayCycles_(delayCycles) {
    initializeContextId();
    stateRegistry_ = new StateRegistry();
}
 
/**
 * Default destructor
 */
OperationContextPimpl::~OperationContextPimpl() {
    delete stateRegistry_;
    stateRegistry_ = NULL;
}
 
/**
 * Checks if state with given name can be found in the context.
 *
 * @param name Name of the state.
 * @return True if the state is found.
 */
bool 
OperationContextPimpl::hasState(const char* name) const {
    try {
        state(name);
    } catch (const KeyNotFound&) {
        return false;
    }
    return true;    
}
 
/**
 * Generates an unique context id for the current OperationContext instance.
 */
void
OperationContextPimpl::initializeContextId() {
    contextId_ = nextContextId_;
    nextContextId_++;
}
 
/**
 * Looks up the (concrete) operation state identified by the string name.
 *
 * @param name The state identifier.
 * @return The found operation state instance.
 * @exception KeyNotFound If state by name couldn't be found.
 */
OperationState&
OperationContextPimpl::state(const char* name) const {
 
    StateRegistry::const_iterator i = stateRegistry_->find(name);
 
    if (i == stateRegistry_->end()) {
        throw KeyNotFound(__FILE__, __LINE__, __func__, 
                          "OperationContextPimpl: State not found.");
    }
 
    return *(*i).second;
}
 
/**
 * Advances the internal clock of each registered operation state object.
 */
void 
OperationContextPimpl::advanceClock(OperationContext& context) {
 
    StateRegistry::iterator i = stateRegistry_->begin();
 
    while (i != stateRegistry_->end()) {
        (*i).second->advanceClock(context);
        ++i;
    }
    ++cycleCount_;
}
 
/**
 * Registers the operation state for given name.
 *
 * Called in the createState() of the custom OperationBehavior classes.
 * If state with given identifier is already found in the context, program
 * is aborted. This method is only for internal use. Used by the macro 
 * definitions of OSAL.hh.
 *
 * @param name The identifier for the registered state instance.
 * @param stateToRegister The state instance.
 */
void 
OperationContextPimpl::registerState(OperationState* stateToRegister) {
    string stateName = stateToRegister->name();
    // RegisterState() and unregisterState() are supposed to be used
    // only internally, they are not part of the "client IF", therefore
    // it's reasonable to assert.
    assert(!hasState(stateName.c_str()));
    (*stateRegistry_)[stateName] = stateToRegister;    
}
 
/**
 * Unregisters the operation state of given name.
 *
 * This method is only for internal use. Used by the macro 
 * definitions of OSAL.hh.
 *
 * Called in deleteState() of the custom OperationBehavior classes.
 * Aborts if there's no state with given identifier in the context.
 */    
void 
OperationContextPimpl::unregisterState(const char* name) {
    // RegisterState() and unregisterState() are supposed to be used
    // only internally, they are not part of the "client IF", therefore
    // it's reasonable to assert.
    assert(hasState(name));
    stateRegistry_->erase(name);
}
 
/**
 * Returns a reference to a Memory Module wrapper instance.
 *
 * This instance can be accessed by the function unit and behavior 
 * simulation methods to simulate memory access.
 *
 * @return The Memory instance.
 */
Memory& 
OperationContextPimpl::memory() {
    return *memory_;
}
 
/**
 * Sets the reference to a Memory Module instance.
 *
 * This instance can be accessed by the function unit and behavior 
 * simulation methods to simulate memory access.
 *
 * @param memory The Memory instance.
 */
void
OperationContextPimpl::setMemory(Memory* memory) {
    memory_ = memory;
}
 
/**
 * Returns the unique id of the OperationContext instance.
 *
 * @return The unique id for the OperationContext instance.
 */
int 
OperationContextPimpl::contextId() const {
    return contextId_;
}
 
/**
 * Returns the FU name of the OperationContext instance.
 *
 * @return The FU name for the OperationContext instance.
 */
const TCEString& 
OperationContextPimpl::functionUnitName() {
    return FUName_;
}
 
/**
 * Returns a reference to the current value of the program counter register.
 *
 * The value of the program counter can be changed through this reference. 
 * This is used to implement control transfer operations like jumps and calls 
 * to subroutines. 
 *
 * @return The program counter value as a reference.
 */
InstructionAddress& 
OperationContextPimpl::programCounter() {
    return programCounter_;
}
 
/**
 * TODO
 */
void
OperationContextPimpl::setUpdateProgramCounter(bool value) {
    updateProgramCounter_ = value;
}
 
/**
 * TODO
 */
bool
OperationContextPimpl::updateProgramCounter() const {
    return updateProgramCounter_;
}
 
/**
 * Returns a reference to the current value of the return address register.
 *
 * The value of the return address can be changed through this reference. 
 * This is used in implementing calls to subroutines.
 *
 * @return The return address value as a reference.
 */
SimValue&
OperationContextPimpl::returnAddress() {
    return returnAddress_;
}
 
/**
 * Makes the return address to be saved in the RA register.
 *
 * This is used by CALL instruction to save the RA before jumping.
 *
 * @param value Value to set to.
 * @return The return address value as a reference.
 */
void
OperationContextPimpl::setSaveReturnAddress(bool value) {
    saveReturnAddress_ = value;
}
 
/**
 * Returns true if RA should saved before executing next control flow 
 * operation.
 *
 * @return The return address value as a reference.
 */
bool
OperationContextPimpl::saveReturnAddress() {
    return saveReturnAddress_;
}
 
/**
 * Returns true if there are no operation state objects stored in the
 * context.
 *
 * @return True if there are no operation state objects stored in the
 * context.
 */
bool 
OperationContextPimpl::isEmpty() const {
    return stateRegistry_->size() == 0;
}
 
/**
 * Returns true if the context has memory model associated with it.
 * 
 * @return True if the context has memory model associated with it.
 */
bool
OperationContextPimpl::hasMemoryModel() const {
    return (memory_ != NULL);
}
 
/**
 * Returns the count of cycles simulated.
 *
 * Can be used to implement real time timer operations, etc. Uses
 * the simulator's cycle count, if available, otherwise uses internal
 * cycle counter that is incremented with the advanceClock();
 */
CycleCount
OperationContextPimpl::cycleCount() const {
    if (cycleCountVar_ != NULL) {
        return *cycleCountVar_;
    } else {
        return cycleCount_;
    }
}
 
/**
 * Returns the amount of pipeline delay cycles.
 */
int
OperationContextPimpl::branchDelayCycles() {
    return branchDelayCycles_; 
}