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);
}
@Override
public void applyTransferFunction(Instr i) {
Variable dst = null;
boolean dirtied = false;
boolean hitDFBarrier = false;
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) {
dirtied = true;
tmpState.unboxedVars.put(dst, srcType);
} else if (srcType == Fixnum.class) {
dirtied = true;
tmpState.unboxedVars.put(dst, srcType);
}
} else if (i instanceof ClosureAcceptingInstr) {
Operand o = ((ClosureAcceptingInstr) i).getClosureArg();
// Process calls specially -- these are what we want to optimize!
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
if (receiverType == Float.class
|| (receiverType == Fixnum.class && argType == Float.class)) {
dirtied = true;
Class dstType = m.getUnboxedResultType(Float.class);
setOperandType(tmpState, dst, dstType);
tmpState.unboxedVars.put(dst, dstType);
// If 'r' and 'a' are not already in unboxed forms at this point,
// they will get unboxed after this, because we want to opt. this call
if (r instanceof Variable) {
tmpState.unboxedVars.put((Variable) r, Float.class);
}
if (a instanceof Variable) {
tmpState.unboxedVars.put((Variable) a, Float.class);
}
} else if (receiverType == Float.class
|| (receiverType == Fixnum.class && argType == Fixnum.class)) {
dirtied = true;
Class dstType = m.getUnboxedResultType(Fixnum.class);
setOperandType(tmpState, dst, dstType);
tmpState.unboxedVars.put(dst, dstType);
// If 'r' and 'a' are not already in unboxed forms at this point,
// they will get unboxed after this, because we want to opt. this call
if (r instanceof Variable) {
tmpState.unboxedVars.put((Variable) r, Fixnum.class);
}
if (a instanceof Variable) {
tmpState.unboxedVars.put((Variable) a, Fixnum.class);
}
} 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) {
// Fetch the nested unboxing-analysis problem, creating one if necessary
IRClosure cl = ((WrappedIRClosure) o).getClosure();
UnboxableOpsAnalysisProblem subProblem =
(UnboxableOpsAnalysisProblem) cl.getDataFlowSolution(DataFlowConstants.UNBOXING);
if (subProblem == null) {
subProblem = new UnboxableOpsAnalysisProblem();
subProblem.setup(cl);
cl.setDataFlowSolution(DataFlowConstants.UNBOXING, subProblem);
}
UnboxableOpsAnalysisNode exitNode = subProblem.getExitNode();
UnboxableOpsAnalysisNode entryNode = subProblem.getEntryNode();
// Init it to MEET(state-on-entry, state-on-exit).
// The meet is required to account for participation of the closure in a loop.
// Ex: f = 0.0; n.times { f += 10; }
entryNode.inState = new UnboxState();
for (Variable v : tmpState.types.keySet()) {
if (v instanceof LocalVariable) {
entryNode.inState.types.put(v, tmpState.types.get(v));
}
}
entryNode.inState.computeMEET(exitNode.outState);
// Compute solution
subProblem.compute_MOP_Solution();
// 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 {
// Black hole -- 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.
updateUnboxedVarsInfo(i, tmpState, dst, hasExceptionsRescued(), hitDFBarrier);
}
}