scale.backend.mips
Class LoadInstruction

java.lang.Object
  scale.backend.Instruction
      scale.backend.mips.MipsInstruction
          scale.backend.mips.LoadInstruction

All Implemented Interfaces:

java.lang.Cloneable

public class LoadInstruction
extends MipsInstruction

This class represents Mips load instructions.

$Id: LoadInstruction.java,v 1.14 2006-11-09 00:56:07 burrill Exp $

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

Instance=06,10 Op=1x

Field Summary

protected int	dftn The function applied to the displacement (e.g., %hi, %lo, etc).
protected int	rd the rd register.
protected int	rs1 the rs1 register
protected Displacement	value the literal value

Fields inherited from class scale.backend.mips.MipsInstruction

opcode

Constructor Summary

protected	LoadInstruction(int opcode, int rd, int rs1, Displacement value)
protected	LoadInstruction(int opcode, int rd, int rs1, Displacement value, int dftn)

Method Summary

void	assembler(Assembler asm, Emit emit) Insert the assembler representation of the instruction into the output stream.
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.
int[]	getSrcRegisters() Return the source registers or null if none.
boolean	independent(Instruction inst, RegisterSet registers) Return true if this instruction is independent of the specified instruction.
boolean	isStore() Return true if this is a store-into-memory instruction.
void	nullify(RegisterSet rs) Mark the instruction as no longer needed.
void	remapDestRegister(int oldReg, int newReg) Map the registers defined in the instruction as destinations to the specified register.
void	remapRegisters(int[] map) Map the virtual registers referenced in the instruction to the specified real registers.
void	remapSrcRegister(int oldReg, int newReg) Map the registers used in the instruction as sources to the specified register.
void	specifyRegisterUsage(RegisterAllocator rs, int index, int strength) Specify the registers used by this instruction.
java.lang.String	toString()
boolean	uses(int register, RegisterSet registers) Return true if the instruction uses the register.

Methods inherited from class scale.backend.mips.MipsInstruction

assembleDisp, getOpcode, instructionSize, setOpcode

Methods inherited from class scale.backend.Instruction

clone, copy, ehash, getBBID, getCopyDest, getCopySrc, getExecutionCycles, getFunctionalUnit, getLoopNumber, getNext, getPredicate, getPredicates, getTag, isBranch, isCopy, isLabel, isLoad, isMandatory, isMarker, isPhi, isPredicated, isPredicatedOnTrue, isPrefetch, isSpillInstruction, isSpillLoadPoint, isSpillStorePoint, markSpillInstruction, mods, nullified, 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

Field Detail

rd

protected int rd

the rd register.

value

protected Displacement value

the literal value

dftn

protected int dftn

The function applied to the displacement (e.g., %hi, %lo, etc).

rs1

protected int rs1

the rs1 register

Constructor Detail

LoadInstruction

protected LoadInstruction(int opcode,
                          int rd,
                          int rs1,
                          Displacement value,
                          int dftn)

LoadInstruction

protected LoadInstruction(int opcode,
                          int rd,
                          int rs1,
                          Displacement value)

Method Detail

created

public static int created()

Return the number of instances of this class created.

isStore

public boolean isStore()

Return true if this is a store-into-memory instruction.

Overrides:

isStore in class Instruction

getDestRegister

public int getDestRegister()

Return the destination register or -1 if none.

Overrides:

getDestRegister in class Instruction

getSrcRegisters

public int[] getSrcRegisters()

Return the source registers or null if none.

Overrides:

getSrcRegisters in class Instruction

remapRegisters

public void remapRegisters(int[] map)

Description copied from class: Instruction

Map the virtual registers referenced in the instruction to the specified real registers. The mapping is specified using an array that is indexed by the virtual register to return the real register.

Overrides:

remapRegisters in class MipsInstruction

Parameters:

map - maps from the virtual register to real register

remapSrcRegister

public void remapSrcRegister(int oldReg,
                             int newReg)

Map the registers used in the instruction as sources to the specified register. If the register is not used as a source register, no change is made.

Specified by:

remapSrcRegister in class Instruction

Parameters:

oldReg - is the previous source register

newReg - is the new source register

remapDestRegister

public void remapDestRegister(int oldReg,
                              int newReg)

Map the registers defined in the instruction as destinations to the specified register. If the register is not used as a destination register, no change is made.

Specified by:

remapDestRegister in class Instruction

Parameters:

oldReg - is the previous destination register

newReg - is the new destination register

specifyRegisterUsage

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

Specify the registers used by this instruction.

Overrides:

specifyRegisterUsage in class MipsInstruction

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 MipsInstruction

defs

public boolean defs(int register,
                    RegisterSet registers)

Return true if the instruction sets the register.

Overrides:

defs in class MipsInstruction

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.

Specified by:

independent in class Instruction

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

nullify

public void nullify(RegisterSet rs)

Mark the instruction as no longer needed.

Overrides:

nullify in class Instruction

assembler

public void assembler(Assembler asm,
                      Emit emit)

Insert the assembler representation of the instruction into the output stream.

Overrides:

assembler in class MipsInstruction

toString

public java.lang.String toString()

Overrides:

toString in class MipsInstruction