scale.backend.x86
Class X86Branch

java.lang.Object
  scale.backend.Instruction
      scale.backend.Branch
          scale.backend.x86.X86Branch

All Implemented Interfaces:

java.lang.Cloneable

Direct Known Subclasses:

X86DBranch, X86RBranch

public class X86Branch
extends Branch

This is the class for all machine X86 branch instructions.

$Id$

Copyright 2008 by James H. Burrill
All Rights Reserved.

Field Summary

protected int	opcode the instruction opcode
protected boolean	pt True branch predicted?

Constructor Summary

protected

X86Branch(int opcode, boolean pt, int numTargets)

Method Summary

java.lang.String	assembleDisp(Assembler asm, Displacement disp, int ftn) Generate a String representation of a Displacement that can be used by the assembly code generater.
void	assembler(Assembler asm, Emit emit) Insert the assembler representation of the instruction into the output stream.
static void	buildAddress(java.lang.StringBuffer buf, int baseReg, int indexReg, Displacement disp, int scale)
boolean	canBeDeleted(RegisterSet registers) Return true if the instruction can be deleted without changing program semantics.
protected boolean	checkForm(int opcode)
boolean	defs(int register, RegisterSet registers) Return true if the instruction sets the register.
Displacement	getDisplacement()
int	getOpcode() Return the numeric opcode of the instruction.
int	getOperandSize() Return 1, 2, 4, or 8 depending on the size of the operand, in bytes, specified for the instruction.
char	getOperandSizeLabel() Return 'b', 'w', 'l', or 'x' depending on the size of the operand specified for the instruction.
boolean	getPt() Return true if the branch is predicited to occur.
int	getReg()
int	getReg2()
int	instructionSize() Return the number of bytes required for the instruction.
boolean	isReversed() Return true if the instruction modifies memory.
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.
void	setDisplacement(Displacement disp)
protected void	setOpcode(int opcode)
void	setOperandSize(int size) Set the operand size specified for the instruction.
void	setReg(int reg)
void	setReg2(int reg2)
protected void	setReturnedStructSize(int size) Specifiy the size of the struct returned by the call or 0 if none.
void	setScale(int scale) Set the scale factor specified for the instruction.
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.Branch

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

Methods inherited from class scale.backend.Instruction

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

pt

protected boolean pt

True branch predicted?

Constructor Detail

X86Branch

protected X86Branch(int opcode,
                    boolean pt,
                    int numTargets)

Parameters:

numTargets - is the number of successors of this instruction.

pt - is true if the true condition is predicted For routine calls, it does not include the routine called.

Method Detail

checkForm

protected boolean checkForm(int opcode)

getOpcode

public final 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 final void setOpcode(int opcode)

isReversed

public final boolean isReversed()

Return true if the instruction modifies memory.

getPt

public boolean getPt()

Return true if the branch is predicited to occur.

getDisplacement

public Displacement getDisplacement()

setDisplacement

public void setDisplacement(Displacement disp)

getReg

public int getReg()

setReg

public void setReg(int reg)

getReg2

public int getReg2()

setReg2

public void setReg2(int reg2)

setReturnedStructSize

protected void setReturnedStructSize(int size)

Specifiy the size of the struct returned by the call or 0 if none.

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)

Description copied from class: Branch

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

assembler

public void assembler(Assembler asm,
                      Emit emit)

Description copied from class: Instruction

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

Specified by:

assembler in class Instruction

assembleDisp

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

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

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()

Description copied from class: Instruction

Return the number of bytes required for the instruction.

Specified by:

instructionSize in class Instruction

Returns:

the number of bytes required for the Branch Instruction

isUnconditional

public boolean isUnconditional()

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

setScale

public void setScale(int scale)

Set the scale factor specified for the instruction. The value must be 1, 2, 4, or 8.

getOperandSize

public int getOperandSize()

Return 1, 2, 4, or 8 depending on the size of the operand, in bytes, specified for the instruction.

getOperandSizeLabel

public char getOperandSizeLabel()

Return 'b', 'w', 'l', or 'x' depending on the size of the operand specified for the instruction.

setOperandSize

public void setOperandSize(int size)

Set the operand size specified for the instruction. The value must be 1, 2, 4, or 8.

toString

public java.lang.String toString()

Overrides:

toString in class Branch

buildAddress

public static void buildAddress(java.lang.StringBuffer buf,
                                int baseReg,
                                int indexReg,
                                Displacement disp,
                                int scale)