scale.backend.mips
Class MipsBranch

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

All Implemented Interfaces:

java.lang.Cloneable

Direct Known Subclasses:

CmpBranchInstruction, FltBranchInstruction, JumpLabelInstruction, JumpRegInstruction

public abstract class MipsBranch
extends Branch

This is the abstract class for all machine MipsBranch instructions.

$Id: MipsBranch.java,v 1.15 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	delaySlot The delay slot instruction is kept as part of the branch.
protected int	opcode the instruction opcode

Constructor Summary

protected

MipsBranch(int opcode, int numTargets, MipsInstruction delaySlot)

Method Summary

protected void	assembleDelay(Assembler asm, Emit emit) Assemble the delay slot instruction.
java.lang.String	assembleDisp(Assembler asm, Displacement disp) Generate a String representation of a Displacement that can be used by the assembly code generater.
boolean	canBeDeleted(RegisterSet registers) Return true if the instruction can be deleted without changing program semantics.
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	getDelaySlot()
int	getOpcode() Return the numeric opcode of the instruction.
int	instructionSize() Return the number of bytes required for the Branch Instruction.
boolean	isUnconditional() Return true if the branch is an unconditional transfer of control to a new address.
boolean	mods(int register, RegisterSet registers) Return true if the instruction clobbers the register.
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	setDelaySlot(MipsInstruction delaySlot)
protected void	setOpcode(int opcode)
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.Branch

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

Methods inherited from class scale.backend.Instruction

assembler, clone, ehash, getBBID, getCopyDest, getCopySrc, getDestRegister, getFunctionalUnit, getLoopNumber, getNext, getPredicate, getPredicates, getSrcRegisters, 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

opcode

protected int opcode

the instruction opcode

delaySlot

protected MipsInstruction delaySlot

The delay slot instruction is kept as part of the branch.

Constructor Detail

MipsBranch

protected MipsBranch(int opcode,
                     int numTargets,
                     MipsInstruction delaySlot)

Parameters:

opcode - specifies the instruction opcode

numTargets - is the number of successors of this instruction.

delaySlot - is the delay slot instruction For routine calls, it does not include the routine called.

Method Detail

specifyRegisterUsage

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

Specify the registers used by this instruction.

Overrides:

specifyRegisterUsage in class Branch

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)

remapRegisters

public void remapRegisters(int[] map)

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 Branch

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 Branch

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 Branch

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 Branch

defs

public boolean defs(int register,
                    RegisterSet registers)

Return true if the instruction sets the register.

Overrides:

defs in class Branch

mods

public boolean mods(int register,
                    RegisterSet registers)

Return true if the instruction clobbers the register.

Overrides:

mods in class Branch

assembleDisp

public java.lang.String assembleDisp(Assembler asm,
                                     Displacement disp)

Generate a String representation of a Displacement that can be used by the assembly code generater.

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.

Specified by:

getOpcode in class Instruction

setOpcode

protected void setOpcode(int opcode)

getDelaySlot

public MipsInstruction getDelaySlot()

setDelaySlot

protected void setDelaySlot(MipsInstruction delaySlot)

canBeDeleted

public boolean canBeDeleted(RegisterSet registers)

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

Overrides:

canBeDeleted in class Instruction

instructionSize

public int instructionSize()

Return the number of bytes required for the Branch Instruction.

Specified by:

instructionSize in class Instruction

assembleDelay

protected final void assembleDelay(Assembler asm,
                                   Emit emit)

Assemble the delay slot instruction.

delayToStringBuf

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

toString() helper method.

isUnconditional

public boolean isUnconditional()

Return true if the branch is an unconditional transfer of control to a new address.