ImmediateControlField.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 ImmediateControlField.cc
 *
 * Implementation of ImmediateControlField class.
 *
 * @author Lasse Laasonen 2005 (lasse.laasonen-no.spam-tut.fi)
 * @note rating: red
 */
 
#include "ImmediateControlField.hh"
#include "BinaryEncoding.hh"
#include "MoveSlot.hh"
#include "NullInstructionField.hh"
#include "MathTools.hh"
#include "MapTools.hh"
#include "Application.hh"
#include "ObjectState.hh"
 
using std::string;
using std::pair;
 
const std::string ImmediateControlField::OSNAME_IMM_CONTROL_FIELD = "ic_field";
const std::string ImmediateControlField::OSNAME_TEMPLATE_MAP = "temp_map";
const std::string ImmediateControlField::OSKEY_TEMPLATE_NAME = "temp_name";
const std::string ImmediateControlField::OSKEY_ENCODING = "encoding";
 
/**
 * The constructor.
 *
 * Registers the immediate control field to the parent BinaryEncoding
 * automatically. The field is added as the leftmost field of the TTA
 * instruction.
 *
 * @param parent The parent encoding map.
 * @exception ObjectAlreadyExists If the given encoding map has an immediate
 *                                control field already.
 */
ImmediateControlField::ImmediateControlField(BinaryEncoding& parent)
    : InstructionField(&parent) {
    setParent(NULL);
    parent.setImmediateControlField(*this);
    setParent(&parent);
}
 
/**
 * The constructor.
 *
 * Loads the state of the object from the given ObjectState tree.
 *
 * @param state The ObjectState tree.
 * @param parent The parent encoding map.
 * @exception ObjectStateLoadingException If an error occurs while loading
 *                                        the state.
 * @exception ObjectAlreadyExists If the given encoding map has an immediate
 *                                control field already.
 */
ImmediateControlField::ImmediateControlField(
    const ObjectState* state, BinaryEncoding& parent)
    : InstructionField(state, &parent) {
    loadState(state);
    setParent(NULL);
    parent.setImmediateControlField(*this);
    setParent(&parent);
}
 
/**
 * The destructor.
 */
ImmediateControlField::~ImmediateControlField() {
    BinaryEncoding* oldParent = parent();
    assert(oldParent != NULL);
    setParent(NULL);
    oldParent->unsetImmediateControlField();
}
 
 
/**
 * Returns the parent encoding map.
 *
 * @return The parent encoding map.
 */
BinaryEncoding*
ImmediateControlField::parent() const {
    InstructionField* parent = InstructionField::parent();
    if (parent == NULL) {
    return NULL;
    } else {
    BinaryEncoding* encoding = dynamic_cast<BinaryEncoding*>(parent);
    assert(encoding != NULL);
    return encoding;
    }
}
 
 
/**
 * Returns the number of instruction templates with a binary encoding assigned.
 *
 * @return The number of instruction templates.
 */
int
ImmediateControlField::templateCount() const {
    return templates_.size();
}
 
 
/**
 * Returns the name of the instruction template encoded in this field at the
 * given position.
 *
 * @param index The position index.
 * @exception OutOfRange If the given index is negative or not smaller than the
 *                       number of encodings of instruction templates.
 */
std::string
ImmediateControlField::instructionTemplate(int index) const {
    if (index < 0 || index >= templateCount()) {
    const string procName = "ImmediateControlField::instructionTemplate";
    throw OutOfRange(__FILE__, __LINE__, procName);
    }
 
    int counter(0);
    for (EncodingMap::const_iterator iter = templates_.begin();
     iter != templates_.end(); iter++) {
 
    if (counter == index) {
        return iter->first;
    } else {
        counter++;
    }
    }
 
    assert(false);
    return "";
}
 
/**
 * Tells whether the instruction template with the given name has has a binary
 * encoding in this field.
 *
 * @param name Name of the instruction template.
 * @return True if the template has a binary encoding, otherwise false.
 */
bool
ImmediateControlField::hasTemplateEncoding(const std::string& name) const {
    return MapTools::containsKey(templates_, name);
}
 
 
/**
 * Returns the code that identifies the instruction template with the given
 * name.
 *
 * @param name Name of the instruction template.
 * @return The code that identifies the given instruction template.
 * @exception InstanceNotFound If the given instruction template does not have
 *                             a binary encoding in this field.
 */
unsigned int
ImmediateControlField::templateEncoding(const std::string& name) const {
    if (!hasTemplateEncoding(name)) {
    const string procName = "ImmediateControlField::templateEncoding";
    throw InstanceNotFound(__FILE__, __LINE__, procName);
    }
 
    EncodingMap::const_iterator iter = templates_.find(name);
    assert(iter != templates_.end());
    return iter->second;
}
 
/**
 * Assings the given code to the instruction template identified by the given
 * name.
 *
 * If the given instruction template has an encoding already, replaces the
 * encoding with the given one.
 *
 * @param name Name of the instruction template.
 * @param encoding The code to be assigned.
 * @exception ObjectAlreadyExists If the given code is already assigned to
 *                                another instruction template.
 */
void
ImmediateControlField::addTemplateEncoding(
    const std::string& name, unsigned int encoding) {
    if (MapTools::containsValue(templates_, encoding) &&
    MapTools::keyForValue<string>(templates_, encoding) != name) {
    const string procName = "ImmediateControlField::addTemplateEncoding";
    throw ObjectAlreadyExists(__FILE__, __LINE__, procName);
    }
 
 
    pair<EncodingMap::iterator, bool> result =
    templates_.insert(pair<string, int>(name, encoding));
 
    if (!result.second) {
    // if there is a code for the template already
    EncodingMap::iterator iter = templates_.find(name);
    assert(iter != templates_.end());
    iter->second = encoding;
    }
}
 
/**
 * Removes the code of the instruction template with the given name.
 *
 * @param name Name of the instruction template.
 */
void
ImmediateControlField::removeTemplateEncoding(const std::string& name) {
    templates_.erase(name);
}
 
 
/**
 * Returns the bit width of the immediate control field.
 *
 * @return The bit width of the field.
 */
int
ImmediateControlField::width() const {
    int minWidth(0);
    for (EncodingMap::const_iterator iter = templates_.begin();
     iter != templates_.end(); iter++) {
    int encoding = iter->second;
    int requiredBits = MathTools::bitLength(encoding);
    if (requiredBits > minWidth) {
        minWidth = requiredBits;
    }
    }
    return minWidth + extraBits();
}
 
 
/**
 * Always returns 0.
 *
 * @return 0.
 */
int
ImmediateControlField::childFieldCount() const {
    return 0;
}
 
 
/**
 * Always throws OutOfRange exception because immediate control field does
 * not have any child fields.
 *
 * @return Never returns.
 * @exception OutOfRange Always thrown.
 */
InstructionField&
ImmediateControlField::childField(int) const {
    const string procName = "ImmediateControlField::childField";
    throw OutOfRange(__FILE__, __LINE__, procName);
}
 
/**
 * Loads the state of the immediate control field from the given ObjectState
 * tree.
 *
 * @param state The ObjectState tree.
 * @exception ObjectStateLoadingException If an error occurs while loading
 *                                        the state.
 */
void
ImmediateControlField::loadState(const ObjectState* state) {
    clearTemplateEncodings();
    InstructionField::loadState(state);
    const string procName = "ImmediateControlField::loadState";
 
    if (state->name() != OSNAME_IMM_CONTROL_FIELD) {
    throw ObjectStateLoadingException(__FILE__, __LINE__, procName);
    }
 
    try {
    for (int i = 0; i < state->childCount(); i++) {
        ObjectState* child = state->child(i);
        if (child->name() != OSNAME_TEMPLATE_MAP) {
        throw ObjectStateLoadingException(
            __FILE__, __LINE__, procName);
        }
        string tempName = child->stringAttribute(OSKEY_TEMPLATE_NAME);
        int encoding = child->intAttribute(OSKEY_ENCODING);
        addTemplateEncoding(tempName, encoding);
    }
 
    } catch (const Exception& exception) {
    throw ObjectStateLoadingException(
        __FILE__, __LINE__, procName, exception.errorMessage());
    }
}
 
/**
 * Saves the state of the immediate control field to an ObjectState tree.
 *
 * @return The newly created ObjectState tree.
 */
ObjectState*
ImmediateControlField::saveState() const {
 
    ObjectState* state = InstructionField::saveState();
    state->setName(OSNAME_IMM_CONTROL_FIELD);
    state->setAttribute(OSKEY_POSITION, relativePosition());
 
    for (int i = 0; i < templateCount(); i++) {
    string temp = instructionTemplate(i);
    int encoding = templateEncoding(temp);
    ObjectState* tempMap = new ObjectState(OSNAME_TEMPLATE_MAP);
    state->addChild(tempMap);
    tempMap->setAttribute(OSKEY_TEMPLATE_NAME, temp);
    tempMap->setAttribute(OSKEY_ENCODING, encoding);
    }
 
    return state;
}
 
 
/**
 * Clears all the template encodings from the immediate control field.
 */
void
ImmediateControlField::clearTemplateEncodings() {
    templates_.clear();
}