ProcedureTransferTracker.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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    copy of this software and associated documentation files (the "Software"),
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/**
 * @file ProcedureTransferTracker.cc
 *
 * Definition of ProcedureTransferTracker class.
 *
 * @author Pekka Jääskeläinen 2005 (pjaaskel-no.spam-cs.tut.fi)
 * @note rating: red
 */
 
#include "ProcedureTransferTracker.hh"
#include "ExecutionTrace.hh"
#include "Application.hh"
#include "SimulatorFrontend.hh"
#include "SimulatorToolbox.hh"
#include "SimulationEventHandler.hh"
#include "Instruction.hh"
#include "ControlUnit.hh"
#include "Move.hh"
#include "Terminal.hh"
#include "TerminalFUPort.hh"
#include "SpecialRegisterPort.hh"
#include "StringTools.hh"
#include "Operation.hh"
#include "Machine.hh"
#include "Program.hh"
 
/**
 * Constructor for the default implementation of storing the transfers 
 * to a TraceDB.
 *
 * @param subject The SimulationController which is observed.
 * @param traceDB The Execution Trace Database instance in which the
 *                trace is stored. Expects that the database is open
 *                for writing.
 */
ProcedureTransferTracker::ProcedureTransferTracker(
    SimulatorFrontend& subject,
    ExecutionTrace& traceDB) : 
    Listener(), subject_(subject), traceDB_(&traceDB), 
    previousInstruction_(NULL) {
    subject.eventHandler().registerListener(
        SimulationEventHandler::SE_CYCLE_END, this);
}
 
/**
 * Constructors for the derived implementations.
 *
 * The implementation should override the addProcedureTransfer() to
 * record the transfers as wished.
 */
ProcedureTransferTracker::ProcedureTransferTracker(
    SimulatorFrontend& subject) : 
    Listener(), subject_(subject), traceDB_(NULL),
    previousInstruction_(NULL) {
    subject.eventHandler().registerListener(
        SimulationEventHandler::SE_CYCLE_END, this);
}
 
/**
 * Destructor.
 */
ProcedureTransferTracker::~ProcedureTransferTracker() {
    subject_.eventHandler().unregisterListener(
        SimulationEventHandler::SE_CYCLE_END, this);
}
 
/**
 * Stored procedure transfer data to execution database.
 *
 * Last executed instruction is saved and its procedure is compared to the
 * procedure of the current instruction. If they differ, a procedure transfer
 * has happened and data of it is stored in trace database.
 */
void 
ProcedureTransferTracker::handleEvent() {
 
    InstructionAddress lastExecutedInstrAddr = 
        subject_.lastExecutedInstruction();
    // the instruction that WAS executed in the current cycle (this handles
    // clock cycle *end* events)
    const TTAProgram::Instruction& currentInstruction =
        subject_.program().instructionAt(lastExecutedInstrAddr);
 
    if (!currentInstruction.isInProcedure() ||
        (previousInstruction_ != NULL && &(currentInstruction.parent()) == 
         &(previousInstruction_->parent()))) {
        // the instrution is not in a procedure (probably hand coded 
        // assembly program without procedure info), or there was no
        // procedure transfer
        previousInstruction_ = &currentInstruction;
        return;
    }
 
    bool entry = true;
    // the address of the call or the return
    InstructionAddress lastControlFlowInstructionAddress = 0;
    // in case this is the first instruction, consider this a procedure
    // entry (to the first procedure)
    if (previousInstruction_ != NULL) {
        // find the instruction which is responsible for the procedure 
        // change: it should be the instruction at the last executed
        // instruction at the source procedure minus the count of delay
        // slots
        lastControlFlowInstructionAddress = 
            previousInstruction_->address().location() - 
            subject_.machine().controlUnit()->delaySlots();
        const TTAProgram::Instruction& lastControlFlowInstruction =
            subject_.program().instructionAt(
                lastControlFlowInstructionAddress);
 
        // check if the instruction contains a move to gcu.jump.
        // if there's no such a move, we'll assume it's a call
        for (int i = 0; i < lastControlFlowInstruction.moveCount(); ++i) {
        
            TTAProgram::Move& lastMove = lastControlFlowInstruction.move(i);
            if (dynamic_cast<TTAProgram::TerminalFUPort*>(
                &lastMove.destination()) == 0) {
                continue;
            }
            if (lastMove.destination().isOpcodeSetting() && lastMove.isJump()) {
                entry = false;
                break;
            }
        }
    }  
    previousInstruction_ = &currentInstruction;
    addProcedureTransfer(
        subject_.cycleCount(), lastExecutedInstrAddr, 
        lastControlFlowInstructionAddress, entry);
}
 
/**
 * This function is called to record a procedure transfer (call or return).
 *
 * The default implementation stores the transfer to a TraceDB.
 */
void 
ProcedureTransferTracker::addProcedureTransfer(
    ClockCycleCount cycle,
    InstructionAddress address,
    InstructionAddress sourceAddress,
    bool isEntry) {
 
    if (traceDB_ == NULL)
        return;
 
    try {
        traceDB_->addProcedureTransfer(
            cycle, address, sourceAddress, 
            isEntry? ExecutionTrace::PT_ENTRY : ExecutionTrace::PT_EXIT);
    } catch (const Exception& e) {
        debugLog("Error while writing TraceDB: " + e.errorMessage());
    }
}