SimpleOperationExecutor.cc

Go to the documentation of this file.

/*
    Copyright (c) 2002-2009 Tampere University.
 
    This file is part of TTA-Based Codesign Environment (TCE).
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
    to deal in the Software without restriction, including without limitation
    the rights to use, copy, modify, merge, publish, distribute, sublicense,
    and/or sell copies of the Software, and to permit persons to whom the
    Software is furnished to do so, subject to the following conditions:
 
    The above copyright notice and this permission notice shall be included in
    all copies or substantial portions of the Software.
 
    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    DEALINGS IN THE SOFTWARE.
 */
/**
 * @file SimpleOperationExecutor.cc
 *
 * Definition of SimpleOperationExecutor class.
 *
 * @author Jussi Nykänen 2004 (nykanen-no.spam-cs.tut.fi)
 * @author Pekka Jääskeläinen 2005 (pjaaskel-no.spam-cs.tut.fi)
 * @author Viljami Korhonen 2007 (viljami.korhonen-no.spam-tut.fi)
 * @note rating: red
 */
 
#include "SimpleOperationExecutor.hh"
#include "Operation.hh"
#include "Operand.hh"
#include "SequenceTools.hh"
#include "OperationContext.hh"
#include "PortState.hh"
#include "SimulatorToolbox.hh"
#include "OperationPool.hh"
#include "Application.hh"
 
using std::vector;
using std::string;
 
/**
 * Constructor.
 *
 * @param latency Latency of the operation.
 * @param parent Parent of the OperationExecutor.
 */
SimpleOperationExecutor::SimpleOperationExecutor(
    int latency, 
    FUState& parent) : 
    OperationExecutor(parent), nextSlot_(0), context_(NULL), 
    pendingOperations_(0) {
    
    for (int i = 0; i < latency; i++) {
        BufferCell cell;
        buffer_.push_back(cell);
    }
    hasPendingOperations_ = true;
}
 
/**
 * Destructor.
 */
SimpleOperationExecutor::~SimpleOperationExecutor() {
}
 
/**
 * Returns the latency of the executor.
 *
 * @return The latency of the executor.
 */
int
SimpleOperationExecutor::latency() const {
    return buffer_.size();
}
 
/**
 * Starts new operation.
 *
 * First original inputs and outputs are stored. Then outputs of the operation
 * are stored. Then operation is triggered.
 *
 * @param op Operation to be triggered.
 * @todo This can be optimized a lot: try to initialize the vector as rarely
 *       as possible.
 */
void
SimpleOperationExecutor::startOperation(Operation& op) {
 
    BufferCell& nextSlot = buffer_[nextSlot_];
 
    const bool reuseBindings = 
        nextSlot.boundOperation_ != NULL && nextSlot.boundOperation_ == &op;
 
    if (!reuseBindings) {
        const std::size_t inputOperands = op.numberOfInputs();
        const std::size_t outputOperands = op.numberOfOutputs();
        const std::size_t operandCount = inputOperands + outputOperands;
 
        assert(operandCount <= EXECUTOR_MAX_OPERAND_COUNT);
        // let the operation access the input port values directly,
        for (std::size_t i = 1; i <= inputOperands; ++i) {
            /// @todo create valueConst() and value() to avoid these uglies
            nextSlot.io_[i - 1] = &(const_cast<SimValue&>(binding(i).value()));
        }
 
        // create new temporary SimValues for the outputs, assume
        // indexing of outputs starts after inputs 
        /// @todo Fix! This should not probably be assumed, or at least
        /// user should be notified if his operand ids are not what
        /// are expected.
        for (std::size_t i = inputOperands + 1; i <= operandCount; ++i) {
            nextSlot.ioOrig_[i - 1].setBitWidth(op.operand(i).width());  
            nextSlot.io_[i - 1] = &nextSlot.ioOrig_[i - 1];
        }
        nextSlot.boundOperation_ = &op;
    }
 
    nextSlot.operation_ = &op;
    nextSlot.ready_ = op.simulateTrigger(nextSlot.io_, *context_);
    ++pendingOperations_;
    hasPendingOperations_ = true;
}
 
/**
 * Advances clock by one cycle.
 *
 * Takes the oldest result in the pipeline and makes it visible in the
 * function unit's ports.
 */
void
SimpleOperationExecutor::advanceClock() {
 
    int index = (nextSlot_ + 1) % buffer_.size();
    
    BufferCell& oldestEntry = buffer_[index];
    Operation* oldestOperation = oldestEntry.operation_;
    if (oldestOperation != NULL) {
 
        const std::size_t inputOperands = oldestOperation->numberOfInputs();
        const std::size_t outputOperands = oldestOperation->numberOfOutputs();
        const std::size_t operandCount = inputOperands + outputOperands;
        for (std::size_t i = inputOperands + 1; i <= operandCount; ++i) {
            PortState& port = binding(i);
            port.setValue(*oldestEntry.io_[i - 1]);
        }
        // results now moved to the FU output ports, "lifetime" of this
        // operation execution ends in this FU
        oldestEntry.operation_ = NULL;
        --pendingOperations_;
        hasPendingOperations_ = (pendingOperations_ > 0);
    }
    nextSlot_++;
    nextSlot_ = nextSlot_ % buffer_.size();
}
 
/**
 * Copies OperationExecutor.
 *
 * @return The copied OperationExecutor.
 */
OperationExecutor*
SimpleOperationExecutor::copy() {
    return new SimpleOperationExecutor(*this);
}
 
/**
 * Sets the OperationContext for the OperationExecutor.
 *
 * @param context New OperationContext.
 */
void
SimpleOperationExecutor::setContext(OperationContext& context) {
    context_ = &context;
}