/** Find non-locals variables. Algorithm from Briggs, Cooper, Harvey and Simpson */
public BitSet findNonLocals() {
BitSet nonLocals = new BitSet(nbVar);
BitSet killed = new BitSet(nbVar);
BitSet emptySet = new BitSet(nbVar);
for (BasicBlock bb = firstBB; bb != null; bb = bb.getNext()) {
// clear killed set
killed.and(emptySet);
Iterator insts = bb.getInstructions();
while (insts.hasNext()) {
QInst inst = (QInst) insts.next();
QOperandBox[] ops = inst.getUses();
for (int i = 0; i < ops.length; ++i) {
QOperand op = ops[i].getOperand();
if (op instanceof QVar) {
int r = ((QVar) op).getRegister();
if (!killed.get(r)) {
nonLocals.set(r);
}
}
}
if (inst.defVar()) {
QOperand op = inst.getDefined().getOperand();
if (op instanceof QVar) {
int r = ((QVar) op).getRegister();
killed.set(r);
}
}
}
}
return nonLocals;
}
/** Precolor the SSA init variable */
protected void precolorInitVariables() {
Iterator insts = start.getInstructions();
while (insts.hasNext()) {
QInst inst = (QInst) insts.next();
if (inst instanceof QDeclareInitialised) {
QOperand op = inst.getDefined().getOperand();
if (op instanceof QSSAVar) {
SSAVar var = ((QSSAVar) op).getSSAVar();
var.setColor(var.getSourceIndex());
}
}
}
}