harpoon.Analysis.Instr
Class DemandDrivenRegAlloc

java.lang.Object
  harpoon.Analysis.Instr.RegAlloc
      harpoon.Analysis.Instr.DemandDrivenRegAlloc

public class DemandDrivenRegAlloc
extends RegAlloc

DemandDrivenRegAlloc performs Demand-Driven Register Allocation for a set of Instrs in a Code.

Version:

$Id: DemandDrivenRegAlloc.java,v 1.2 2002/02/25 20:57:30 cananian Exp $

Author:

Felix S. Klock II <pnkfelix@mit.edu>

Nested Class Summary

Nested classes/interfaces inherited from class harpoon.Analysis.Instr.RegAlloc

RegAlloc.Factory, RegAlloc.IntermediateCode, RegAlloc.IntermediateCodeFactory, RegAlloc.RestoreProxy, RegAlloc.SpillLoad, RegAlloc.SpillProxy, RegAlloc.SpillStore

Field Summary

Fields inherited from class harpoon.Analysis.Instr.RegAlloc

bbFact, checked, code, DEBUG, frame, GLOBAL, LOCAL, TIME

Constructor Summary

protected

DemandDrivenRegAlloc(Code code) Creates a DemandDrivenRegAlloc.

Method Summary

protected void	generateRegAssignment() Assigns registers in the code for this.
protected Derivation	getDerivation() stub implementation.

Methods inherited from class harpoon.Analysis.Instr.RegAlloc

abstractSpillFactory, abstractSpillFactory, allRegs, back, codeFactory, codeFactory, computeBasicBlocks, concreteSpillFactory, expand, fixupSpillCode, getBack, getGrapherFor, getUseDeferFor, hasRegister, isRegister, lastUse, reachableInstrs, replace, resolveOutstandingTemps, rfi

Methods inherited from class java.lang.Object

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

Constructor Detail

DemandDrivenRegAlloc

protected DemandDrivenRegAlloc(Code code)

Creates a DemandDrivenRegAlloc.
Design Issue: should there be a RegAlloc object for every method, or just for every machine target? For now it seems associating a new one with every method will save a lot of headaches.
requires: 1. Local register allocation has been run on code already.

Method Detail

getDerivation

protected Derivation getDerivation()

stub implementation.

Specified by:

getDerivation in class RegAlloc

generateRegAssignment

protected void generateRegAssignment()

Description copied from class: RegAlloc

Assigns registers in the code for this.
effects: Partially or completely allocates registers for the values defined and used in the code for this. Values will be preserved in the code; any live value will be stored before its assigned register is overwritten.
Loads and Stores in general are added in the form of SpillLoads and SpillStores; the main RegAlloc class will use resolveOutstandingTemps() to replace these "fake" loads and stores with frame specified Memory instructions.

Specified by:

generateRegAssignment in class RegAlloc

See Also:

RegAlloc.resolveOutstandingTemps()