org.jikesrvm.compilers.opt.regalloc

Class SpillCostEstimator

java.lang.Object

org.jikesrvm.compilers.opt.regalloc.SpillCostEstimator

Direct Known Subclasses:

BlockCountSpillCost, BrainDeadSpillCost, SimpleSpillCost

abstract class SpillCostEstimator
extends Object

An object that returns an estimate of the relative cost of spilling a symbolic register.

Field Summary

Fields

Modifier and Type	Field and Description
private HashMap<Register,Double>	map

Constructor Summary

Constructors

Constructor and Description
SpillCostEstimator()

Method Summary

Modifier and Type	Method and Description
(package private) abstract void	calculate(IR ir) Calculates the estimated cost for each register.
(package private) double	getCost(Register r) Returns a number that represents an estimate of the relative cost of spilling register r.
protected void	update(Register r, double delta) Updates the cost for a particular register.

Methods inherited from class java.lang.Object

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

Field Detail

map

private final HashMap<Register,Double> map

Constructor Detail

SpillCostEstimator

SpillCostEstimator()

Method Detail

getCost

double getCost(Register r)

Returns a number that represents an estimate of the relative cost of spilling register r.

Parameters:

r - the register to check

Returns:

a cost estimate for spilling; may be zero

calculate

abstract void calculate(IR ir)

Calculates the estimated cost for each register.

Parameters:

ir - the IR object

update

protected void update(Register r,
                      double delta)

Updates the cost for a particular register.

Parameters:

r - register whose cost is to be updated

delta - change in cost for the register