com.android.dx.ssa
Class SsaMethod

java.lang.Object
  com.android.dx.ssa.SsaMethod

public final class SsaMethod
extends Object

A method in SSA form.

Method Summary

int	blockIndexToRopLabel(int bi)
int	borrowSpareRegister(int category) Borrows a register to use as a temp.
void	computeReachability() Computes reachability for all blocks in the method.
void	deleteInsns(Set<SsaInsn> deletedInsns) Deletes all insns in the set from this method.
void	forEachBlockDepthFirst(boolean reverse, SsaBasicBlock.Visitor v) Walks the basic block tree in depth-first order, calling the visitor method once for every block.
void	forEachBlockDepthFirstDom(SsaBasicBlock.Visitor v) Visits blocks in dom-tree order, starting at the current node.
void	forEachInsn(SsaInsn.Visitor visitor) Visits all insns in this method.
void	forEachPhiInsn(PhiInsn.Visitor v) Visits each phi insn in this method
ArrayList<SsaBasicBlock>	getBlocks()
int	getCountReachableBlocks() Returns the count of reachable blocks in this method: blocks that have predecessors (or are the start block)
SsaInsn	getDefinitionForRegister(int reg) Returns the insn that defines the given register
SsaBasicBlock	getEntryBlock()
int	getEntryBlockIndex()
SsaBasicBlock	getExitBlock()
int	getExitBlockIndex()
int	getParamWidth()
int	getRegCount()
ArrayList<SsaInsn>[]	getUseListCopy() Returns a modifiable copy of the register use list.
List<SsaInsn>	getUseListForRegister(int reg) Returns the list of all source uses (not results) for a register.
static IntList	indexListFromLabelList(BasicBlockList ropBlocks, IntList labelList) Builds an IntList of block indices from a basic block list and a list of labels taken from Rop form.
boolean	isRegALocal(RegisterSpec spec) Checks to see if the given SSA reg is ever associated with a local local variable.
boolean	isStatic() Returns true if this is a static method.
SsaBasicBlock	makeNewGotoBlock() Makes a new basic block for this method, which is empty besides a single GOTO.
int	makeNewSsaReg() Makes a new SSA register.
void	mapRegisters(RegisterMapper mapper) Remaps unversioned registers.
static SsaMethod	newFromRopMethod(RopMethod ropMethod, int paramWidth, boolean isStatic)
void	onInsnsChanged() Indicates that the instruction list has changed or the SSA register count has increased, so that internal datastructures that rely on it should be rebuild.
void	returnSpareRegisters() Returns all borrowed registers.
void	setBackMode() Sets "back-convert mode".

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

newFromRopMethod

public static SsaMethod newFromRopMethod(RopMethod ropMethod,
                                         int paramWidth,
                                         boolean isStatic)

Parameters:

ropMethod - rop-form method to convert from

paramWidth - the total width, in register-units, of the method's parameters

isStatic - true if this method has no this pointer argument

indexListFromLabelList

public static IntList indexListFromLabelList(BasicBlockList ropBlocks,
                                             IntList labelList)

Builds an IntList of block indices from a basic block list and a list of labels taken from Rop form.

Parameters:

ropBlocks - Rop blocks

labelList - list of rop block labels

Returns:

IntList of block indices

makeNewGotoBlock

public SsaBasicBlock makeNewGotoBlock()

Makes a new basic block for this method, which is empty besides a single GOTO. Successors and predecessors are not yet set.

Returns:

new block

getEntryBlockIndex

public int getEntryBlockIndex()

Returns:

block index of first execution block

getEntryBlock

public SsaBasicBlock getEntryBlock()

Returns:

first execution block

getExitBlockIndex

public int getExitBlockIndex()

Returns:

block index of exit block or -1 if there is none

getExitBlock

public SsaBasicBlock getExitBlock()

Returns:

null-ok; block of exit block or null if there is none

blockIndexToRopLabel

public int blockIndexToRopLabel(int bi)

Parameters:

bi - block index or -1 for none

Returns:

rop label or {code -1} if bi was -1

getRegCount

public int getRegCount()

Returns:

count of registers used in this method

getParamWidth

public int getParamWidth()

Returns:

the total width, in register units, of the method's parameters

isStatic

public boolean isStatic()

Returns true if this is a static method.

Returns:

true if this is a static method

borrowSpareRegister

public int borrowSpareRegister(int category)

Borrows a register to use as a temp. Used in the phi removal process. Call returnSpareRegisters() when done.

Parameters:

category - width (1 or 2) of the register

Returns:

register number to use

returnSpareRegisters

public void returnSpareRegisters()

Returns all borrowed registers.

getBlocks

public ArrayList<SsaBasicBlock> getBlocks()

Returns:

non-null; basic block list. Do not modify.

getCountReachableBlocks

public int getCountReachableBlocks()

Returns the count of reachable blocks in this method: blocks that have predecessors (or are the start block)

Returns:

>= 0; number of reachable basic blocks

computeReachability

public void computeReachability()

Computes reachability for all blocks in the method. First clears old values from all blocks, then starts with the entry block and walks down the control flow graph, marking all blocks it finds as reachable.

mapRegisters

public void mapRegisters(RegisterMapper mapper)

Remaps unversioned registers.

Parameters:

mapper - maps old registers to new.

getDefinitionForRegister

public SsaInsn getDefinitionForRegister(int reg)

Returns the insn that defines the given register

Parameters:

reg - register in question

Returns:

insn (actual instance from code) that defined this reg or null if reg is not defined.

onInsnsChanged

public void onInsnsChanged()

Indicates that the instruction list has changed or the SSA register count has increased, so that internal datastructures that rely on it should be rebuild. In general, the various other on* methods should be called in preference when changes occur if they are applicable.

getUseListForRegister

public List<SsaInsn> getUseListForRegister(int reg)

Returns the list of all source uses (not results) for a register.

Parameters:

reg - register in question

Returns:

unmodifiable instruction list

getUseListCopy

public ArrayList<SsaInsn>[] getUseListCopy()

Returns a modifiable copy of the register use list.

Returns:

modifiable copy of the use-list, indexed by register

isRegALocal

public boolean isRegALocal(RegisterSpec spec)

Checks to see if the given SSA reg is ever associated with a local local variable. Each SSA reg may be associated with at most one local var.

Parameters:

spec - non-null; ssa reg

Returns:

true if reg is ever associated with a local

makeNewSsaReg

public int makeNewSsaReg()

Makes a new SSA register. For use after renaming has completed.

Returns:

>=0; new SSA register.

forEachInsn

public void forEachInsn(SsaInsn.Visitor visitor)

Visits all insns in this method.

Parameters:

visitor - non-null; callback interface

forEachPhiInsn

public void forEachPhiInsn(PhiInsn.Visitor v)

Visits each phi insn in this method

Parameters:

v - non-null; callback.

forEachBlockDepthFirst

public void forEachBlockDepthFirst(boolean reverse,
                                   SsaBasicBlock.Visitor v)

Walks the basic block tree in depth-first order, calling the visitor method once for every block. This depth-first walk may be run forward from the method entry point or backwards from the method exit points.

Parameters:

reverse - true if this should walk backwards from the exit points

v - non-null; callback interface. parent is set unless this is the root node

forEachBlockDepthFirstDom

public void forEachBlockDepthFirstDom(SsaBasicBlock.Visitor v)

Visits blocks in dom-tree order, starting at the current node. The parent parameter of the Visitor.visitBlock callback is currently always set to null.

Parameters:

v - non-null; callback interface

deleteInsns

public void deleteInsns(Set<SsaInsn> deletedInsns)

Deletes all insns in the set from this method.

Parameters:

deletedInsns - non-null; insns to delete

setBackMode

public void setBackMode()

Sets "back-convert mode". Set during back-conversion when registers are about to be mapped into a non-SSA namespace. When true, use and def lists are unavailable.