scale.backend.alpha
Class LoadInstruction

java.lang.Object
  scale.backend.Instruction
      scale.backend.alpha.MemoryInstruction
          scale.backend.alpha.LoadInstruction

All Implemented Interfaces:

java.lang.Cloneable

public class LoadInstruction
extends MemoryInstruction

This class represents Alpha load instructions.

$Id: LoadInstruction.java,v 1.27 2006-11-16 17:49:36 burrill Exp $

Copyright 2005 by the Scale Compiler Group,
Department of Computer Science
University of Massachusetts,
Amherst MA. 01003, USA
All Rights Reserved.

Field Summary

Fields inherited from class scale.backend.alpha.MemoryInstruction

displacement, opcode, ra, rb, relocType

Constructor Summary

LoadInstruction(int opcode, int ra, int rb)

LoadInstruction(int opcode, int ra, int rb, Displacement displacement)

LoadInstruction(int opcode, int ra, int rb, Displacement displacement, int relocType)

Method Summary

boolean	canBeDeleted(RegisterSet registers) Return true if the instruction can be deleted without changing program semantics.
static int	created() Return the number of instances of this class created.
boolean	defs(int register, RegisterSet registers) Return true if the instruction sets the register.
int	getDestRegister() Return the destination register or -1 if none.
boolean	independent(Instruction inst, RegisterSet registers) Return true if this instruction is independent of the specified instruction.
boolean	isLoad() Return true if this is a load-from-memory instruction.
boolean	mods(int register, RegisterSet registers) Return true if the instruction modifies the register.
void	specifyRegisterUsage(RegisterAllocator rs, int index, int strength) Specify the registers used by this instruction.
boolean	uses(int register, RegisterSet registers) Return true if the instruction uses the register.

Methods inherited from class scale.backend.alpha.MemoryInstruction

assembler, getDisplacement, getExecutionCycles, getFunctionalUnit, getOpcode, getRa, getRb, getRelocType, instructionSize, remapDestRegister, remapRegisters, remapSrcRegister, setDisplacement, setRb, toString

Methods inherited from class scale.backend.Instruction

clone, copy, ehash, getBBID, getCopyDest, getCopySrc, getLoopNumber, getNext, getPredicate, getPredicates, getSrcRegisters, getTag, isBranch, isCopy, isLabel, isMandatory, isMarker, isPhi, isPredicated, isPredicatedOnTrue, isPrefetch, isSpillInstruction, isSpillLoadPoint, isSpillStorePoint, isStore, markSpillInstruction, nullified, nullify, numPredicates, removePredicates, setBBID, setLoopNumber, setMandatory, setNext, setPredicate, setPredicate, setPredicatedOnTrue, setPredicates, setsSpecialReg, setTag, specifyNotSpillLoadPoint, specifySpillStorePoint

Methods inherited from class java.lang.Object

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

Constructor Detail

LoadInstruction

public LoadInstruction(int opcode,
                       int ra,
                       int rb)

LoadInstruction

public LoadInstruction(int opcode,
                       int ra,
                       int rb,
                       Displacement displacement)

LoadInstruction

public LoadInstruction(int opcode,
                       int ra,
                       int rb,
                       Displacement displacement,
                       int relocType)

Method Detail

created

public static int created()

Return the number of instances of this class created.

getDestRegister

public int getDestRegister()

Return the destination register or -1 if none.

Overrides:

getDestRegister in class Instruction

isLoad

public boolean isLoad()

Return true if this is a load-from-memory instruction.

Overrides:

isLoad in class Instruction

specifyRegisterUsage

public void specifyRegisterUsage(RegisterAllocator rs,
                                 int index,
                                 int strength)

Specify the registers used by this instruction.

Specified by:

specifyRegisterUsage in class Instruction

Parameters:

rs - is the register set in use

index - is an index associated with the instruction

strength - is the importance of the instruction

See Also:

RegisterAllocator.useRegister(int,int,int), RegisterAllocator.defRegister(int,int)

uses

public boolean uses(int register,
                    RegisterSet registers)

Return true if the instruction uses the register.

Overrides:

uses in class Instruction

defs

public boolean defs(int register,
                    RegisterSet registers)

Return true if the instruction sets the register.

Overrides:

defs in class Instruction

mods

public boolean mods(int register,
                    RegisterSet registers)

Return true if the instruction modifies the register.

Overrides:

mods in class Instruction

independent

public boolean independent(Instruction inst,
                           RegisterSet registers)

Return true if this instruction is independent of the specified instruction. If instructions are independent, than one instruction can be moved before or after the other instruction without changing the semantics of the program.

Overrides:

independent in class MemoryInstruction

Parameters:

inst - is the specified instruction

canBeDeleted

public boolean canBeDeleted(RegisterSet registers)

Return true if the instruction can be deleted without changing program semantics.

Overrides:

canBeDeleted in class Instruction