BridgeEncoding.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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    The above copyright notice and this permission notice shall be included in
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/**
 * @file BridgeEncoding.cc
 *
 * Implementation of BridgeEncoding class.
 *
 * @author Lasse Laasonen 2005 (lasse.laasonen-no.spam-tut.fi)
 * @note rating: red
 */
 
#include <string>
 
#include "BridgeEncoding.hh"
#include "SourceField.hh"
#include "Application.hh"
#include "ObjectState.hh"
 
using std::string;
 
const std::string BridgeEncoding::OSNAME_BRIDGE_ENCODING = "bridge_encoding";
const std::string BridgeEncoding::OSKEY_BRIDGE_NAME = "bridge_name";
 
 
/**
 * The constructor.
 *
 * Creates an encoding for the given bridge and registers it into the given
 * source field.
 *
 * @param name Name of the bridge.
 * @param encoding The encoding.
 * @param extraBits The number of extra (zero) bits in the encoding.
 * @param parent The parent source field.
 * @exception ObjectAlreadyExists If the parent source field has an encoding
 *                                for this bridge already or if the encoding
 *                                is ambiguous with some other encoding.
 */
BridgeEncoding::BridgeEncoding(
    const std::string& name, unsigned int encoding, unsigned int extraBits,
    SourceField& parent)
    : Encoding(encoding, extraBits, NULL), bridge_(name) {
    parent.addBridgeEncoding(*this);
    setParent(&parent);
}
 
/**
 * The constructor.
 *
 * Loads the state of the object from the given ObjectState instance.
 *
 * @param state The ObjectState instance.
 * @param parent The parent source field.
 * @exception ObjectStateLoadingException If an error occurs while loading
 *                                        the state.
 * @exception ObjectAlreadyExists If the parent source field has an encoding
 *                                for this bridge already or if the encoding
 *                                is ambiguous with some other encoding.
 */
BridgeEncoding::BridgeEncoding(const ObjectState* state, SourceField& parent)
    : Encoding(state, NULL), bridge_("") {
    const string procName = "BridgeEncoding::BridgeEncoding";
 
    if (state->name() != OSNAME_BRIDGE_ENCODING) {
    throw ObjectStateLoadingException(__FILE__, __LINE__, procName);
    }
 
    try {
    bridge_ = state->stringAttribute(OSKEY_BRIDGE_NAME);
    } catch (const Exception& exception) {
    throw ObjectStateLoadingException(
        __FILE__, __LINE__, procName, exception.errorMessage());
    }
 
    parent.addBridgeEncoding(*this);
    setParent(&parent);
}
 
/**
 * The destructor.
 */
BridgeEncoding::~BridgeEncoding() {
    SourceField* parent = this->parent();
    setParent(NULL);
    parent->removeBridgeEncoding(*this);
}
 
 
/**
 * Returns the parent source field.
 *
 * @return The parent source field.
 */
SourceField*
BridgeEncoding::parent() const {
    InstructionField* parent = Encoding::parent();
    if (parent != NULL) {
        SourceField* sField = dynamic_cast<SourceField*>(parent);
        assert(sField != NULL);
        return sField;
    } else {
        return NULL;
    }
}
 
 
/**
 * Returns the name of the bridge.
 *
 * @return The name of the bridge.
 */
std::string
BridgeEncoding::bridgeName() const {
    return bridge_;
}
 
 
/**
 * Returns the position of the bridge encoding within the source field.
 *
 * @return The position.
 */
int
BridgeEncoding::bitPosition() const {
    if (parent()->componentIDPosition() == BinaryEncoding::RIGHT) {
        return 0;
    } else {
        return parent()->width() - parent()->extraBits() - width();
    }
}
 
    
/**
 * Saves the state of the object to an ObjectState instance.
 *
 * @return The newly created ObjectState instance.
 */
ObjectState*
BridgeEncoding::saveState() const {
    ObjectState* state = Encoding::saveState();
    state->setName(OSNAME_BRIDGE_ENCODING);
    state->setAttribute(OSKEY_BRIDGE_NAME, bridgeName());
    return state;
}