Package mars.tools

Class BHTSimulator

java.lang.Object

java.awt.Component

java.awt.Container

java.awt.Window

java.awt.Frame

javax.swing.JFrame

mars.tools.AbstractMarsToolAndApplication

mars.tools.BHTSimulator

All Implemented Interfaces:

ActionListener, ImageObserver, MenuContainer, Serializable, EventListener, Observer, Accessible, RootPaneContainer, WindowConstants, MarsTool

public class BHTSimulator
extends AbstractMarsToolAndApplication
implements ActionListener

A MARS tool for simulating branch prediction with a Branch History Table (BHT)

The simulation is based on observing the access to the instruction memory area (text segment). If a branch instruction is encountered, a prediction based on a BHT is performed. The outcome of the branch is compared with the prediction and the prediction is updated accordingly. Statistics about the correct and incorrect number of predictions can be obtained for each BHT entry. The number of entries in the BHT and the history that is considered for each prediction can be configured interactively. A change of the configuration however causes a re-initialization of the BHT.

The tool can be used to show how branch prediction works in case of loops and how effective such simple methods are. In case of nested loops the difference of BHT with 1 or 2 Bit history can be explored and visualized.

Author:

ingo.kofler@itec.uni-klu.ac.at

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.awt.Window

Window.Type

Nested classes/interfaces inherited from class java.awt.Component

Component.BaselineResizeBehavior

Field Summary

Fields

Modifier and Type	Field	Description
static int	BHT_DEFAULT_HISTORY	constant for the default history size
static boolean	BHT_DEFAULT_INITVAL	constant for the default inital value
static int	BHT_DEFAULT_SIZE	constant for the default size of the BHT
static String	BHT_HEADING	the heading of the tool
static String	BHT_NAME	the name of the tool
static String	BHT_VERSION	the version of the tool

Fields inherited from class java.awt.Frame

CROSSHAIR_CURSOR, DEFAULT_CURSOR, E_RESIZE_CURSOR, HAND_CURSOR, ICONIFIED, MAXIMIZED_BOTH, MAXIMIZED_HORIZ, MAXIMIZED_VERT, MOVE_CURSOR, N_RESIZE_CURSOR, NE_RESIZE_CURSOR, NORMAL, NW_RESIZE_CURSOR, S_RESIZE_CURSOR, SE_RESIZE_CURSOR, SW_RESIZE_CURSOR, TEXT_CURSOR, W_RESIZE_CURSOR, WAIT_CURSOR

Fields inherited from class java.awt.Component

BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields inherited from interface java.awt.image.ImageObserver

ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH

Fields inherited from interface javax.swing.WindowConstants

DISPOSE_ON_CLOSE, DO_NOTHING_ON_CLOSE, EXIT_ON_CLOSE, HIDE_ON_CLOSE

Constructor Summary

Constructors

Constructor	Description
BHTSimulator()	Creates a BHT Simulator with given name and heading.

Method Summary

Modifier and Type	Method	Description
void	actionPerformed(ActionEvent event)	Handles the actions when selecting another value in one of the two combo boxes.
String	getName()	Returns the name of the tool.

Methods inherited from class mars.tools.AbstractMarsToolAndApplication

action, go, update

Methods inherited from class javax.swing.JFrame

getAccessibleContext, getContentPane, getDefaultCloseOperation, getGlassPane, getGraphics, getJMenuBar, getLayeredPane, getRootPane, getTransferHandler, isDefaultLookAndFeelDecorated, remove, repaint, setContentPane, setDefaultCloseOperation, setDefaultLookAndFeelDecorated, setGlassPane, setIconImage, setJMenuBar, setLayeredPane, setLayout, setTransferHandler, update

Methods inherited from class java.awt.Frame

addNotify, getCursorType, getExtendedState, getFrames, getIconImage, getMaximizedBounds, getMenuBar, getState, getTitle, isResizable, isUndecorated, remove, removeNotify, setBackground, setCursor, setExtendedState, setMaximizedBounds, setMenuBar, setOpacity, setResizable, setShape, setState, setTitle, setUndecorated

Methods inherited from class java.awt.Window

addPropertyChangeListener, addPropertyChangeListener, addWindowFocusListener, addWindowListener, addWindowStateListener, applyResourceBundle, applyResourceBundle, createBufferStrategy, createBufferStrategy, dispose, getBackground, getBufferStrategy, getFocusableWindowState, getFocusCycleRootAncestor, getFocusOwner, getFocusTraversalKeys, getIconImages, getInputContext, getListeners, getLocale, getModalExclusionType, getMostRecentFocusOwner, getOpacity, getOwnedWindows, getOwner, getOwnerlessWindows, getShape, getToolkit, getType, getWarningString, getWindowFocusListeners, getWindowListeners, getWindows, getWindowStateListeners, hide, isActive, isAlwaysOnTop, isAlwaysOnTopSupported, isAutoRequestFocus, isFocusableWindow, isFocusCycleRoot, isFocused, isLocationByPlatform, isOpaque, isShowing, isValidateRoot, pack, paint, postEvent, removeWindowFocusListener, removeWindowListener, removeWindowStateListener, reshape, setAlwaysOnTop, setAutoRequestFocus, setBounds, setBounds, setCursor, setFocusableWindowState, setFocusCycleRoot, setIconImages, setLocation, setLocation, setLocationByPlatform, setLocationRelativeTo, setMinimumSize, setModalExclusionType, setSize, setSize, setType, setVisible, show, toBack, toFront

Methods inherited from class java.awt.Container

add, add, add, add, add, addContainerListener, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getAlignmentX, getAlignmentY, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getComponentZOrder, getContainerListeners, getFocusTraversalPolicy, getInsets, getLayout, getMaximumSize, getMinimumSize, getMousePosition, getPreferredSize, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusTraversalPolicyProvider, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paintComponents, preferredSize, print, printComponents, remove, removeAll, removeContainerListener, setComponentZOrder, setFocusTraversalKeys, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, setFont, transferFocusDownCycle, validate

Methods inherited from class java.awt.Component

action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, bounds, checkImage, checkImage, contains, contains, createImage, createImage, createVolatileImage, createVolatileImage, disable, dispatchEvent, enable, enable, enableInputMethods, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getBaseline, getBaselineResizeBehavior, getBounds, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphicsConfiguration, getHeight, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocation, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getParent, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getSize, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isDoubleBuffered, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isPreferredSizeSet, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, prepareImage, prepareImage, printAll, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, resize, resize, revalidate, setComponentOrientation, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeysEnabled, setForeground, setIgnoreRepaint, setLocale, setMaximumSize, setMixingCutoutShape, setName, setPreferredSize, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.awt.MenuContainer

getFont, postEvent

Field Details

BHT_DEFAULT_SIZE

public static final int BHT_DEFAULT_SIZE

constant for the default size of the BHT

See Also:

Constant Field Values

BHT_DEFAULT_HISTORY

public static final int BHT_DEFAULT_HISTORY

constant for the default history size

See Also:

Constant Field Values

BHT_DEFAULT_INITVAL

public static final boolean BHT_DEFAULT_INITVAL

constant for the default inital value

See Also:

Constant Field Values

BHT_NAME

public static final String BHT_NAME

the name of the tool

See Also:

Constant Field Values

BHT_VERSION

public static final String BHT_VERSION

the version of the tool

See Also:

Constant Field Values

BHT_HEADING

public static final String BHT_HEADING

the heading of the tool

See Also:

Constant Field Values

Constructor Details

BHTSimulator

public BHTSimulator()

Creates a BHT Simulator with given name and heading.

Method Details

getName

public String getName()

Returns the name of the tool.

Specified by:

getName in interface MarsTool

Specified by:

getName in class AbstractMarsToolAndApplication

Returns:

the tool's name as String

actionPerformed

public void actionPerformed(ActionEvent event)

Handles the actions when selecting another value in one of the two combo boxes. Selecting a different BHT size or history causes a reset of the simulator.

Specified by:

actionPerformed in interface ActionListener