scale.backend.mips
Class MFSpecialInstruction

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

All Implemented Interfaces:

java.lang.Cloneable

public class MFSpecialInstruction
extends MipsInstruction

This class represents Mips MFLO and MFHI instructions.

$Id: MFSpecialInstruction.java,v 1.14 2006-11-16 17:49:37 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

protected MipsInstruction	delaySlot1 The delay slot instructions are kept as part of the MFLO/MFHI instructions.
protected MipsInstruction	delaySlot2
protected int	ra the ra register.

Constructor Summary

MFSpecialInstruction(int opcode, int ra)

MFSpecialInstruction(int opcode, int ra, MipsInstruction delaySlot1, MipsInstruction delaySlot2)

Method Summary

protected void	assembleDelay(Assembler asm, Emit emit) Assemble the delay slot instructions.
void	assembler(Assembler gen, 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.
protected void	delayToStringBuf(java.lang.StringBuffer buf) toString() helper method.
MipsInstruction	getDelaySlot1()
MipsInstruction	getDelaySlot2()
int	getDestRegister() Return the destination register or -1 if none.
int	getOpcode() Return the numeric opcode of the instruction.
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.
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.
protected void	setDelaySlot1(MipsInstruction delaySlot)
protected void	setDelaySlot2(MipsInstruction delaySlot)
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, 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, isStore, markSpillInstruction, mods, 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

Field Detail

ra

protected int ra

the ra register.

delaySlot1

protected MipsInstruction delaySlot1

The delay slot instructions are kept as part of the MFLO/MFHI instructions.

delaySlot2

protected MipsInstruction delaySlot2

Constructor Detail

MFSpecialInstruction

public MFSpecialInstruction(int opcode,
                            int ra,
                            MipsInstruction delaySlot1,
                            MipsInstruction delaySlot2)

MFSpecialInstruction

public MFSpecialInstruction(int opcode,
                            int ra)

Method Detail

created

public static int created()

Return the number of instances of this class created.

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

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

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

getOpcode

public int getOpcode()

Description copied from class: Instruction

Return the numeric opcode of the instruction. This opcode may be an encoding of the actual instruction opcode.

Overrides:

getOpcode in class MipsInstruction

getDelaySlot1

public MipsInstruction getDelaySlot1()

setDelaySlot1

protected void setDelaySlot1(MipsInstruction delaySlot)

getDelaySlot2

public MipsInstruction getDelaySlot2()

setDelaySlot2

protected void setDelaySlot2(MipsInstruction delaySlot)

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

assembleDelay

protected final void assembleDelay(Assembler asm,
                                   Emit emit)

Assemble the delay slot instructions.

delayToStringBuf

protected final void delayToStringBuf(java.lang.StringBuffer buf)

toString() helper method.

assembler

public void assembler(Assembler gen,
                      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