@Override
public Object execute(IRScope scope, Object... data) {
// IRScriptBody do not get explicit call protocol instructions right now.
// They dont push/pop a frame and do other special things like run begin/end blocks.
// So, for now, they go through the runtime stub in IRScriptBody.
//
// Add explicit frame and binding push/pop instrs ONLY for methods -- we cannot handle this in
// closures and evals yet
// If the scope uses $_ or $~ family of vars, has local load/stores, or if its binding has
// escaped, we have
// to allocate a dynamic scope for it and add binding push/pop instructions.
if (explicitCallProtocolSupported(scope)) {
StoreLocalVarPlacementProblem slvpp =
(StoreLocalVarPlacementProblem)
scope.getDataFlowSolution(StoreLocalVarPlacementProblem.NAME);
boolean scopeHasLocalVarStores = false;
boolean bindingHasEscaped = scope.bindingHasEscaped();
CFG cfg = scope.cfg();
if (slvpp != null && bindingHasEscaped) {
scopeHasLocalVarStores = slvpp.scopeHasLocalVarStores();
} else {
// We dont require local-var load/stores to have been run.
// If it is not run, we go conservative and add push/pop binding instrs. everywhere
scopeHasLocalVarStores = bindingHasEscaped;
}
boolean requireFrame = doesItRequireFrame(scope, bindingHasEscaped);
boolean requireBinding = !scope.getFlags().contains(IRFlags.DYNSCOPE_ELIMINATED);
if (requireBinding || requireFrame) {
BasicBlock entryBB = cfg.getEntryBB();
// Push
if (requireFrame) entryBB.addInstr(new PushFrameInstr(scope.getName()));
if (requireBinding) entryBB.addInstr(new PushBindingInstr());
// SSS FIXME: We are doing this conservatively.
// Only scopes that have unrescued exceptions need a GEB.
//
// Allocate GEB if necessary for popping
BasicBlock geb = cfg.getGlobalEnsureBB();
if (geb == null) {
Variable exc = scope.createTemporaryVariable();
geb = new BasicBlock(cfg, Label.getGlobalEnsureBlockLabel());
geb.addInstr(
new ReceiveJRubyExceptionInstr(exc)); // JRuby Implementation exception handling
geb.addInstr(new ThrowExceptionInstr(exc));
cfg.addGlobalEnsureBB(geb);
}
// Pop on all scope-exit paths
for (BasicBlock bb : cfg.getBasicBlocks()) {
Instr i = null;
ListIterator<Instr> instrs = bb.getInstrs().listIterator();
while (instrs.hasNext()) {
i = instrs.next();
// Right now, we only support explicit call protocol on methods.
// So, non-local returns and breaks don't get here.
// Non-local-returns and breaks are tricky since they almost always
// throw an exception and we don't multiple pops (once before the
// return/break, and once when the exception is caught).
if (!bb.isExitBB() && i instanceof ReturnBase) {
// Add before the break/return
instrs.previous();
if (requireBinding) instrs.add(new PopBindingInstr());
if (requireFrame) instrs.add(new PopFrameInstr());
break;
}
}
if (bb.isExitBB() && !bb.isEmpty()) {
// Last instr could be a return -- so, move iterator one position back
if (i != null && i instanceof ReturnBase) instrs.previous();
if (requireBinding) instrs.add(new PopBindingInstr());
if (requireFrame) instrs.add(new PopFrameInstr());
}
if (bb == geb) {
// Add before throw-exception-instr which would be the last instr
if (i != null) {
// Assumption: Last instr should always be a control-transfer instruction
assert i.getOperation().transfersControl()
: "Last instruction of GEB in scope: "
+ scope
+ " is "
+ i
+ ", not a control-xfer instruction";
instrs.previous();
}
if (requireBinding) instrs.add(new PopBindingInstr());
if (requireFrame) instrs.add(new PopFrameInstr());
}
}
}
// This scope has an explicit call protocol flag now
scope.setExplicitCallProtocolFlag();
}
// FIXME: Useless for now
// Run on all nested closures.
for (IRClosure c : scope.getClosures()) run(c, false, true);
// LVA information is no longer valid after the pass
// FIXME: Grrr ... this seems broken to have to create a new object to invalidate
(new LiveVariableAnalysis()).invalidate(scope);
return null;
}
public void unbox(Map<Variable, TemporaryLocalVariable> unboxMap) {
// System.out.println("BB : " + basicBlock + " in " + problem.getScope().getName());
// System.out.println("-- known types on entry:");
// for (Variable v: inState.types.keySet()) {
// if (inState.types.get(v) != Object.class) {
// System.out.println(v + "-->" + inState.types.get(v));
// }
// }
// System.out.print("-- unboxed vars on entry:");
// for (Variable v: inState.unboxedVars) {
// System.out.print(" " + v);
// }
// System.out.println("------");
// System.out.print("-- unboxed vars on exit:");
// for (Variable v: outState.unboxedVars) {
// System.out.print(" " + v);
// }
// System.out.println("------");
CFG cfg = getCFG();
// Compute UNION(unboxedVarsIn(all-successors)) - this.unboxedVarsOut
// All vars in this new set have to be unboxed on exit from this BB
HashMap<Variable, Class> succUnboxedVars = new HashMap<Variable, Class>();
for (BasicBlock b : cfg.getOutgoingDestinations(basicBlock)) {
if (b.isExitBB()) continue;
Map<Variable, Class> xVars = problem.getFlowGraphNode(b).inState.unboxedVars;
for (Variable v2 : xVars.keySet()) {
// VERY IMPORTANT: Pay attention!
//
// Technically, the successors of this node may not all agree on what
// the unboxed type ought to be for 'v2'. For example, one successor might
// want 'v2' in Fixnum form and other might want it in Float form. If that
// happens, we have to add unboxing instructions for each of those expected
// types. However, for now, we are going to punt and assume that our successors
// agree on unboxed types for 'v2'.
succUnboxedVars.put(v2, xVars.get(v2));
}
}
// Same caveat as above applies here
for (Variable v3 : outState.unboxedVars.keySet()) {
succUnboxedVars.remove(v3);
}
// Only worry about vars live on exit from the BB
LiveVariablesProblem lvp =
(LiveVariablesProblem) problem.getScope().getDataFlowSolution(DataFlowConstants.LVP_NAME);
BitSet liveVarsSet = lvp.getFlowGraphNode(basicBlock).getLiveInBitSet();
List<Instr> newInstrs = new ArrayList<Instr>();
boolean unboxedLiveVars = false;
initSolution();
for (Instr i : basicBlock.getInstrs()) {
Variable dst = null;
boolean dirtied = false;
boolean hitDFBarrier = false;
// System.out.println("ORIG: " + i);
if (i.getOperation().transfersControl()) {
// Add unboxing instrs.
for (Variable v : succUnboxedVars.keySet()) {
if (liveVarsSet.get(lvp.getDFVar(v))) {
unboxVar(tmpState, succUnboxedVars.get(v), unboxMap, v, newInstrs);
}
}
unboxedLiveVars = true;
} else {
if (i instanceof ResultInstr) {
dst = ((ResultInstr) i).getResult();
}
if (i instanceof CopyInstr) {
// Copies are easy
Operand src = ((CopyInstr) i).getSource();
Class srcType = getOperandType(tmpState, src);
setOperandType(tmpState, dst, srcType);
// If we have an unboxed type for 'src', we can leave this unboxed.
//
// FIXME: However, if 'src' is a constant, this could unnecessarily
// leave 'src' unboxed and lead to a boxing instruction further down
// at the use site of 'dst'. This indicates that leaving this unboxed
// should ideally be done 'on-demand'. This indicates that this could
// be a backward-flow algo OR that this algo should be run on a
// dataflow graph / SSA graph.
if (srcType == Float.class || srcType == Fixnum.class) {
Operand unboxedSrc =
src instanceof Variable ? getUnboxedVar(srcType, unboxMap, (Variable) src) : src;
TemporaryLocalVariable unboxedDst = getUnboxedVar(srcType, unboxMap, dst);
newInstrs.add(new CopyInstr(Operation.COPY, unboxedDst, unboxedSrc));
tmpState.unboxedVars.put(dst, srcType);
dirtied = true;
}
} else if (i instanceof ClosureAcceptingInstr) {
Operand o = ((ClosureAcceptingInstr) i).getClosureArg();
if (i instanceof CallBase && o == null) {
CallBase c = (CallBase) i;
MethAddr m = c.getMethodAddr();
Operand r = c.getReceiver();
Operand[] args = c.getCallArgs();
if (dst != null && args.length == 1 && m.resemblesALUOp()) {
Operand a = args[0];
Class receiverType = getOperandType(tmpState, r);
Class argType = getOperandType(tmpState, a);
// Optimistically assume that call is an ALU op
Operation unboxedOp;
if ((receiverType == Float.class
|| (receiverType == Fixnum.class && argType == Float.class))
&& (unboxedOp = m.getUnboxedOp(Float.class)) != null) {
dirtied = true;
Class dstType = m.getUnboxedResultType(Float.class);
setOperandType(tmpState, dst, dstType);
tmpState.unboxedVars.put(dst, dstType);
TemporaryLocalVariable unboxedDst = getUnboxedVar(dstType, unboxMap, dst);
r = unboxOperand(tmpState, Float.class, unboxMap, r, newInstrs);
a = unboxOperand(tmpState, Float.class, unboxMap, a, newInstrs);
newInstrs.add(new AluInstr(unboxedOp, unboxedDst, r, a));
} else if ((receiverType == Float.class
|| (receiverType == Fixnum.class && argType == Fixnum.class))
&& (unboxedOp = m.getUnboxedOp(Fixnum.class)) != null) {
dirtied = true;
Class dstType = m.getUnboxedResultType(Fixnum.class);
setOperandType(tmpState, dst, dstType);
tmpState.unboxedVars.put(dst, dstType);
TemporaryLocalVariable unboxedDst = getUnboxedVar(dstType, unboxMap, dst);
r = unboxOperand(tmpState, Fixnum.class, unboxMap, r, newInstrs);
a = unboxOperand(tmpState, Fixnum.class, unboxMap, a, newInstrs);
newInstrs.add(new AluInstr(unboxedOp, unboxedDst, r, a));
} else {
if (receiverType == Fixnum.class && argType == Fixnum.class) {
setOperandType(tmpState, dst, Fixnum.class);
} else {
setOperandType(tmpState, dst, Object.class);
}
if (c.targetRequiresCallersBinding()) {
hitDFBarrier = true;
}
}
} else {
setOperandType(tmpState, dst, Object.class);
}
} else {
if (o instanceof WrappedIRClosure) {
// Since binding can escape in arbitrary ways in the general case,
// assume the worst for now. If we are guaranteed that the closure binding
// is not used outside the closure itself, we can avoid worst-case behavior.
hitDFBarrier = true;
// Fetch the nested unboxing-analysis problem, creating one if necessary
IRClosure cl = ((WrappedIRClosure) o).getClosure();
UnboxableOpsAnalysisProblem subProblem =
(UnboxableOpsAnalysisProblem) cl.getDataFlowSolution(DataFlowConstants.UNBOXING);
UnboxableOpsAnalysisNode exitNode = subProblem.getExitNode();
// Compute solution
subProblem.unbox();
// Update types to MEET(new-state-on-exit, current-state)
tmpState.computeMEETForTypes(exitNode.outState, true);
// As for unboxed var state, since binding can escape in
// arbitrary ways in the general case, assume the worst for now.
// If we are guaranteed that the closure binding is not used
// outside the closure itself, we can avoid worst-case behavior
// and only clear vars that are modified in the closure.
hitDFBarrier = true;
} else {
// Cannot analyze
hitDFBarrier = true;
}
}
} else {
// We dont know how to optimize this instruction.
// So, we assume we dont know type of the result.
// TOP/class --> BOTTOM
setOperandType(tmpState, dst, Object.class);
}
}
if (dirtied) {
tmpState.unboxedDirtyVars.add(dst);
} else {
// Since the instruction didn't run in unboxed form,
// dirty unboxed vars will have to get boxed here.
boxRequiredVars(
i, tmpState, unboxMap, dst, hasExceptionsRescued(), hitDFBarrier, newInstrs);
}
}
// Add unboxing instrs.
if (!unboxedLiveVars) {
for (Variable v : succUnboxedVars.keySet()) {
if (liveVarsSet.get(lvp.getDFVar(v))) {
unboxVar(tmpState, succUnboxedVars.get(v), unboxMap, v, newInstrs);
}
}
}
/*
System.out.println("------");
for (Instr i : newInstrs) {
System.out.println("NEW: " + i);
}
*/
basicBlock.replaceInstrs(newInstrs);
}
