scale.backend.mips
Class CmpBranchInstruction

java.lang.Object
  scale.backend.Instruction
      scale.backend.Branch
          scale.backend.mips.MipsBranch
              scale.backend.mips.CmpBranchInstruction

All Implemented Interfaces:

java.lang.Cloneable

public class CmpBranchInstruction
extends MipsBranch

This class represents the Mips brach on comparison instructions.

$Id: CmpBranchInstruction.java,v 1.12 2007-10-04 19:57:53 burrill Exp $

Copyright 2007 by the Scale Compiler Group,
Department of Computer Science
University of Massachusetts,
Amherst MA. 01003, USA
All Rights Reserved.

Field Summary

protected boolean	link whether or not the branch links
protected int	rs the rs register
protected int	rt the rt register
protected boolean	uses_rt whether or not the instruction uses the rt register
protected Displacement	value A symbolic representation of the displacement

Fields inherited from class scale.backend.mips.MipsBranch

delaySlot, opcode

Constructor Summary

CmpBranchInstruction(int opcode, int rs, Displacement displacement, int numTargets, MipsInstruction delaySlot, boolean link)

CmpBranchInstruction(int opcode, int rs, int rt, Displacement displacement, int numTargets, MipsInstruction delaySlot, boolean link)

Method Summary

void	assembler(Assembler asm, Emit emit) Insert the assembler representation of the instruction into the output stream.
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.
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 ra, 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.MipsBranch

assembleDelay, assembleDisp, canBeDeleted, delayToStringBuf, getDelaySlot, getOpcode, instructionSize, isUnconditional, mods, setDelaySlot, setOpcode

Methods inherited from class scale.backend.Branch

additionalRegsKilled, additionalRegsSet, additionalRegsUsed, addTarget, copy, getBranchProbability, getExecutionCycles, getRegsKilled, getTarget, isBranch, isCall, markAsCall, nullify, numTargets, setBranchProbability, uses

Methods inherited from class scale.backend.Instruction

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

value

protected Displacement value

A symbolic representation of the displacement

rs

protected int rs

the rs register

uses_rt

protected boolean uses_rt

whether or not the instruction uses the rt register

rt

protected int rt

the rt register

link

protected boolean link

whether or not the branch links

Constructor Detail

CmpBranchInstruction

public CmpBranchInstruction(int opcode,
                            int rs,
                            int rt,
                            Displacement displacement,
                            int numTargets,
                            MipsInstruction delaySlot,
                            boolean link)

CmpBranchInstruction

public CmpBranchInstruction(int opcode,
                            int rs,
                            Displacement displacement,
                            int numTargets,
                            MipsInstruction delaySlot,
                            boolean link)

Method Detail

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: MipsBranch

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 MipsBranch

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.

Overrides:

remapSrcRegister in class MipsBranch

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.

Overrides:

remapDestRegister in class MipsBranch

Parameters:

oldReg - is the previous destination register

newReg - is the new destination register

uses

public boolean uses(int register,
                    RegisterSet registers)

Return true if the instruction uses the register.

Overrides:

uses in class MipsBranch

defs

public boolean defs(int register,
                    RegisterSet registers)

Return true if the instruction sets the register.

Overrides:

defs in class MipsBranch

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 Branch

Parameters:

inst - is the specified instruction

specifyRegisterUsage

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

Specify the registers used by this instruction.

Overrides:

specifyRegisterUsage in class MipsBranch

Parameters:

ra - is the register allocator 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)

assembler

public void assembler(Assembler asm,
                      Emit emit)

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

Specified by:

assembler in class Instruction

toString

public java.lang.String toString()

Overrides:

toString in class Branch