return "";
}
public void addStoreAndBindingAllocInstructions() {
BindingStorePlacementProblem bsp = (BindingStorePlacementProblem) _prob;
CFG cfg = bsp.getCFG();
IRExecutionScope s = cfg.getScope();
ListIterator<Instr> instrs = _bb.getInstrs().listIterator();
Set<Variable> dirtyVars = new HashSet<Variable>(_inDirtyVars);
boolean bindingAllocated = _inBindingAllocated;
// If this is the exit BB, we need a binding story on exit only for vars that are both:
//
// (a) dirty,
// (b) live on exit from the closure
// condition reqd. because the variable could be dirty but not used outside.
// Ex: s=0; a.each { |i| j = i+1; sum += j; }; puts sum
// i,j are dirty inside the block, but not used outside
boolean amExitBB = (_bb == cfg.getExitBB());
if (amExitBB) {
/**
LiveVariablesProblem lvp = (LiveVariablesProblem)cfg.getDataFlowSolution(DataFlowConstants.LVP_NAME);
java.util.Collection<Variable> liveVars = lvp.getVarsLiveOnEntry();
System.out.println("\n[In Exit BB] For CFG " + cfg + ":");
System.out.println("\t--> Dirty vars here : " + java.util.Arrays.toString(dirtyVars.toArray()));
System.out.println("\t--> Vars live on entry: " + (liveVars == null ? "NONE" : java.util.Arrays.toString(liveVars.toArray())));
liveVars = lvp.getVarsLiveOnExit();
System.out.println("\t--> Vars live on exit : " + (liveVars == null ? "NONE" : java.util.Arrays.toString(liveVars.toArray())));
**/
LiveVariablesProblem lvp = (LiveVariablesProblem)cfg.getDataFlowSolution(DataFlowConstants.LVP_NAME);
java.util.Collection<Variable> liveVars = lvp.getVarsLiveOnExit();
if (liveVars != null)
dirtyVars.retainAll(liveVars); // Intersection with variables live on exit from the scope
else
dirtyVars.clear();
}
while (instrs.hasNext()) {
Instr i = instrs.next();
if (i.operation == Operation.BINDING_LOAD) continue;
if (i instanceof CallInstr) {
CallInstr call = (CallInstr) i;
Operand o = call.getClosureArg();
if ((o != null) && (o instanceof MetaObject)) {
CFG cl_cfg = ((IRClosure) ((MetaObject) o).scope).getCFG();
BindingStorePlacementProblem cl_bsp = (BindingStorePlacementProblem) cl_cfg.getDataFlowSolution(bsp.getName());
// Add a binding allocation instruction, if necessary
instrs.previous();
if (!bindingAllocated) {
instrs.add(new AllocateBindingInstr(s));
bindingAllocated = true;
}
// If the call is an eval, or if the callee can capture this method's binding,
// we have to spill all variables.
boolean spillAllVars = call.canBeEval() || call.canCaptureCallersBinding();
// Unless we have to spill everything, spill only those dirty variables that are:
// - used in the closure (FIXME: Strictly only those vars that are live at the call site -- but we dont have this info!)
Set<Variable> newDirtyVars = new HashSet<Variable>(dirtyVars);
for (Variable v : dirtyVars) {
if (spillAllVars || cl_bsp.scopeUsesVariable(v)) {
// FIXME: This may not need check for local variable if it is guaranteed to only be local variables.
instrs.add(new StoreToBindingInstr(s, v.getName(), v));
newDirtyVars.remove(v);
} // These variables will be spilt inside the closure -- so they will no longer be dirty after the call site!
else if (cl_bsp.scopeDefinesVariable(v)) {
newDirtyVars.remove(v);
}
}
dirtyVars = newDirtyVars;
instrs.next();
// add stores in the closure
((BindingStorePlacementProblem) cl_cfg.getDataFlowSolution(bsp.getName())).addStoreAndBindingAllocInstructions();
} // Call has no closure && it requires stores
else if (call.requiresBinding()) {
instrs.previous();
if (!bindingAllocated) {
instrs.add(new AllocateBindingInstr(s));