File	Doc	Category	Size	Date	Package
PhiInsn.java	API Doc	Android 1.5 API	10026	Wed May 06 22:41:02 BST 2009	com.android.dx.ssa

PhiInsn

• java.lang.Object
  • SsaInsn

Fields Summary
private int	ropResultReg the original result register of the phi insn is needed during the renaming process after the new result register has already been chosen.
private ArrayList	operands
private RegisterSpecList	sources

Constructors Summary
PhiInsn(RegisterSpec resultReg, SsaBasicBlock block) Constructs a new phi insn with no operands. param resultReg the result reg for this phi insn param block block containing this insn. super(block); this.result = resultReg; ropResultReg = resultReg.getReg();
PhiInsn(int resultReg, SsaBasicBlock block) Makes a phi insn with a void result type. param resultReg the result register for this phi insn. param block block containing this insn. super(block); /* * The type here is bogus: the type depends on the operand and * will be derived later. */ this.result = RegisterSpec.make(resultReg, Type.VOID); ropResultReg = resultReg;

Methods Summary
public void	accept(SsaInsn.Visitor v) {@inheritDoc} v.visitPhiInsn(this);
public void	addPhiOperand(RegisterSpec registerSpec, SsaBasicBlock predBlock) Add an operand to this phi instruction param registerSpec register spec, including type and reg of operand param predBlock Predecessor block to be associated with this operand operands.add(new Operand(registerSpec, predBlock.getIndex(), predBlock.getRopLabel())); // in case someone has already called getSources() sources = null;
public boolean	areAllOperandsEqual() return true if all operands use the same register if (operands.size() == 0 ) { // this should never happen return true; } int firstReg = operands.get(0).regSpec.getReg(); for (Operand o: operands) { if (firstReg != o.regSpec.getReg()) { return false; } } return true;
public boolean	canThrow() {@inheritDoc} Always returns false for PhiInsns return false;
void	changeResultType(com.android.dx.rop.type.TypeBearer type, LocalItem local) Changes the result type. Used during phi type resolution param type non-null; new TypeBearer param local null-ok; new local info, if available result = RegisterSpec.makeLocalOptional(result.getReg(), type, local);
public com.android.dx.ssa.PhiInsn	clone() throw new UnsupportedOperationException("can't clone phi");
public Rop	getOpcode() {@inheritDoc} Always returns null for PhiInsns return null;
public Insn	getOriginalRopInsn() {@inheritDoc} Always returns null for PhiInsns return null;
int	getRopResultReg() return the original rop-form result reg. Useful during renaming. return ropResultReg;
public RegisterSpecList	getSources() Gets sources. Constructed lazily from phi operand data structures and then cached. return sources list if (sources != null) { return sources; } if (operands.size() == 0) { // How'd this happen? A phi insn with no operand? return RegisterSpecList.EMPTY; } int szSources = operands.size(); sources = new RegisterSpecList(szSources); for (int i = 0; i < szSources; i++) { Operand o = operands.get(i); sources.set(i, o.regSpec); } sources.setImmutable(); return sources;
public boolean	hasSideEffect() {@inheritDoc} return Optimizer.getPreserveLocals() && getLocalAssignment() != null;
public boolean	isPhiOrMove() {@inheritDoc} return true;
public boolean	isRegASource(int reg) {@inheritDoc} /* * Avoid creating a sources list in case it has not already been * created */ for (Operand o: operands) { if (o.regSpec.getReg() == reg) { return true; } } return false;
public final void	mapSourceRegisters(RegisterMapper mapper) {@inheritDoc} for (Operand o: operands) { RegisterSpec old = o.regSpec; o.regSpec = mapper.map(old); if (old != o.regSpec) { block.getParent().onSourceChanged(this, old, o.regSpec); } } sources = null;
public int	predBlockIndexForSourcesIndex(int sourcesIndex) Gets the index of the pred block associated with the RegisterSpec at the particular getSources() index. param sourcesIndex index of source in getSources() return block index return operands.get(sourcesIndex).blockIndex;
public java.util.List	predBlocksForReg(int reg, SsaMethod ssaMeth) Returns the list of predecessor blocks associated with all operands that have reg as an operand register. param reg register to look up param ssaMeth method we're operating on return List of predecessor blocks, empty if none ArrayList<SsaBasicBlock> ret = (ArrayList<SsaBasicBlock>)new ArrayList(); for (Operand o: operands) { if (o.regSpec.getReg() == reg) { ret.add(ssaMeth.getBlocks().get(o.blockIndex)); } } return ret;
public java.lang.String	toHuman() return human-readable string for listing dumps return toHumanWithInline(null);
protected final java.lang.String	toHumanWithInline(java.lang.String extra) Returns human-readable string for listing dumps. Allows sub-classes to specify extra text param extra null-ok; the argument to print after the opcode return human-readable string for listing dumps StringBuffer sb = new StringBuffer(80); sb.append(SourcePosition.NO_INFO); sb.append(": "); sb.append("phi"); if (extra != null) { sb.append("("); sb.append(extra); sb.append(")"); } if (result == null) { sb.append(" ."); } else { sb.append(" "); sb.append(result.toHuman()); } sb.append(" <-"); int sz = getSources().size(); if (sz == 0) { sb.append(" ."); } else { for (int i = 0; i < sz; i++) { sb.append(" "); sb.append(sources.get(i).toHuman() + "[b=" + Hex.u2(operands.get(i).ropLabel) + "]"); } } return sb.toString();
public Insn	toRopInsn() Always throws an exeption, since a phi insn may not be converted back to rop form return always throws exception throw new IllegalArgumentException( "Cannot convert phi insns to rop form");
void	updateSourcesToDefinitions(SsaMethod ssaMeth) Updates the TypeBearers of all the sources (phi operands) to be the current TypeBearer of the register-defining instruction's result. This is used during phi-type resolution. Note that local association of operands are preserved in this step. param ssaMeth method that contains this insn for (Operand o: operands) { RegisterSpec def = ssaMeth.getDefinitionForRegister( o.regSpec.getReg()).getResult(); o.regSpec = o.regSpec.withType(def.getType()); } sources = null;