harpoon.Analysis.Quads
Class SimpleConstMap

java.lang.Object
  harpoon.Analysis.Quads.SimpleConstMap

All Implemented Interfaces:

ConstMap

public class SimpleConstMap
extends Object
implements ConstMap

SimpleConstMap is a very simple implementation of ConstMap that reports whether a given Temp is defined by a CONST quad. Although simple, this is sufficient if an SCCOptimize pass has been run on the code factory at some point -- the SCCOptimize transformation will turn more complicated constant expressions into the simple ones that SimpleConstMap detects.

Version:

$Id: SimpleConstMap.java,v 1.4 2002/04/10 03:00:59 cananian Exp $

Author:

C. Scott Ananian <cananian@alumni.princeton.edu>

Constructor Summary

SimpleConstMap(HCode hc)
Creates a SimpleConstMap which provides information about HCode hc.

Method Summary

Object	constMap(HCodeElement hce, Temp t) Determine the constant value of a given temporary in the context of a specific definition.
boolean	isConst(HCodeElement hce, Temp t) Determine whether a given temporary has a constant value at the specified definition point.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SimpleConstMap

public SimpleConstMap(HCode hc)

Creates a SimpleConstMap which provides information about HCode hc.

Method Detail

isConst

public boolean isConst(HCodeElement hce,
                       Temp t)

Description copied from interface: ConstMap

Determine whether a given temporary has a constant value at the specified definition point.

Specified by:

isConst in interface ConstMap

Parameters:

hce - the definition point.

t - the Temp to be examined.

Returns:

true is the given definition point can be proven to give the specified Temp a constant value, false otherwise.

constMap

public Object constMap(HCodeElement hce,
                       Temp t)

Description copied from interface: ConstMap

Determine the constant value of a given temporary in the context of a specific definition.

Specified by:

constMap in interface ConstMap

Parameters:

hce - the definition point.

t - the temporary to be examined.

Returns:

an object corresponding to the constant value of this temporary defined at this point. Values of base types get wrapped in objects in the standard way.