private List<Object[]> buildJVMExceptionTable() {
List<Object[]> etEntries = new ArrayList<Object[]>();
for (BasicBlock b : linearizedBBList) {
// We need handlers for:
// - Unrescuable (handled by ensures),
// - Throwable (handled by rescues)
// in that order since Throwable < Unrescuable
BasicBlock rBB = cfg().getRescuerBBFor(b);
BasicBlock eBB = cfg().getEnsurerBBFor(b);
if ((eBB != null) && (rBB == eBB || rBB == null)) {
// 1. same rescue and ensure handler ==> just spit out one entry with a Throwable class
// 2. only ensure handler ==> just spit out one entry with a Throwable class
etEntries.add(new Object[] {b.getLabel(), eBB.getLabel(), Throwable.class});
} else if (rBB != null) {
// Unrescuable comes before Throwable
if (eBB != null)
etEntries.add(new Object[] {b.getLabel(), eBB.getLabel(), Unrescuable.class});
etEntries.add(new Object[] {b.getLabel(), rBB.getLabel(), Throwable.class});
}
}
// SSS FIXME: This could be optimized by compressing entries for adjacent BBs that have
// identical handlers
// This could be optimized either during generation or as another pass over the table. But, if
// the JVM
// does that already, do we need to bother with it?
return etEntries;
}
@Override
public Object execute(IRScope s, Object... data) {
StoreLocalVarPlacementProblem slvp = new StoreLocalVarPlacementProblem();
// Only run if we are pushing a scope or we are reusing the parents scope.
if (!s.getFlags().contains(IRFlags.DYNSCOPE_ELIMINATED)
|| s.getFlags().contains(IRFlags.REUSE_PARENT_DYNSCOPE)) {
// Make sure flags are computed
s.computeScopeFlags();
Map<Operand, Operand> varRenameMap = new HashMap<Operand, Operand>();
// 1. Figure out required stores
// 2. Add stores
// 3. Figure out required loads
// 4. Add loads
//
// Order is important since loads in 3. depend on stores in 2.
slvp.setup(s);
slvp.compute_MOP_Solution();
// Add stores, assigning an equivalent tmp-var for each local var
slvp.addStores(varRenameMap);
// Once stores have been added, figure out required loads
LoadLocalVarPlacementProblem llvp = new LoadLocalVarPlacementProblem();
llvp.setup(s);
llvp.compute_MOP_Solution();
// Add loads
llvp.addLoads(varRenameMap);
// Rename all local var uses with their tmp-var stand-ins
for (BasicBlock b : s.getCFG().getBasicBlocks()) {
for (Instr i : b.getInstrs()) i.renameVars(varRenameMap);
}
// Run on all nested closures.
//
// In the current implementation, nested scopes are processed independently (unlike Live
// Variable Analysis)
for (IRClosure c : s.getClosures()) run(c, false, true);
// LVA information is no longer valid after this pass
// FIXME: Grrr ... this seems broken to have to create a new object to invalidate
(new LiveVariableAnalysis()).invalidate(s);
}
s.setDataFlowSolution(StoreLocalVarPlacementProblem.NAME, slvp);
return slvp;
}
//
// This can help use eliminate writes to %block that are not used since this is
// a special local-variable, not programmer-defined local-variable
public void computeScopeFlags() {
if (flagsComputed) {
return;
}
// init
canModifyCode = true;
canCaptureCallersBinding = false;
usesZSuper = false;
usesEval = false;
usesBackrefOrLastline = false;
// NOTE: bindingHasEscaped is the crucial flag and it effectively is
// unconditionally true whenever it has a call that receives a closure.
// See CallInstr.computeRequiresCallersBindingFlag
bindingHasEscaped =
(this instanceof IREvalScript); // for eval scopes, bindings are considered escaped ...
hasBreakInstrs = false;
hasNonlocalReturns = false;
canReceiveBreaks = false;
canReceiveNonlocalReturns = false;
// recompute flags -- we could be calling this method different times
// definitely once after ir generation and local optimizations propagates constants locally
// but potentially at a later time after doing ssa generation and constant propagation
if (cfg == null) {
computeScopeFlags(false, getInstrs());
} else {
boolean receivesClosureArg = false;
for (BasicBlock b : cfg.getBasicBlocks()) {
receivesClosureArg = computeScopeFlags(receivesClosureArg, b.getInstrs());
}
}
// Compute flags for nested closures (recursively) and set derived flags.
for (IRClosure cl : getClosures()) {
cl.computeScopeFlags();
if (cl.hasBreakInstrs || cl.canReceiveBreaks) {
canReceiveBreaks = true;
}
if (cl.hasNonlocalReturns || cl.canReceiveNonlocalReturns) {
canReceiveNonlocalReturns = true;
}
if (cl.usesZSuper()) {
usesZSuper = true;
}
}
flagsComputed = true;
}
private Instr[] prepareInstructionsForInterpretation() {
checkRelinearization();
if (linearizedInstrArray != null) return linearizedInstrArray; // Already prepared
try {
buildLinearization(); // FIXME: compiler passes should have done this
depends(linearization());
} catch (RuntimeException e) {
LOG.error("Error linearizing cfg: ", e);
CFG c = cfg();
LOG.error("\nGraph:\n" + c.toStringGraph());
LOG.error("\nInstructions:\n" + c.toStringInstrs());
throw e;
}
// Set up IPCs
HashMap<Label, Integer> labelIPCMap = new HashMap<Label, Integer>();
List<Instr> newInstrs = new ArrayList<Instr>();
int ipc = 0;
for (BasicBlock b : linearizedBBList) {
labelIPCMap.put(b.getLabel(), ipc);
List<Instr> bbInstrs = b.getInstrs();
int bbInstrsLength = bbInstrs.size();
for (int i = 0; i < bbInstrsLength; i++) {
Instr instr = bbInstrs.get(i);
if (instr instanceof Specializeable) {
instr = ((Specializeable) instr).specializeForInterpretation();
bbInstrs.set(i, instr);
}
if (!(instr instanceof ReceiveSelfInstr)) {
newInstrs.add(instr);
ipc++;
}
}
}
// Set up label PCs
setupLabelPCs(labelIPCMap);
// Exit BB ipc
cfg().getExitBB().getLabel().setTargetPC(ipc + 1);
linearizedInstrArray = newInstrs.toArray(new Instr[newInstrs.size()]);
return linearizedInstrArray;
}
// SSS FIXME: Extremely inefficient
public int getEnsurerPC(Instr excInstr) {
depends(cfg());
for (BasicBlock b : linearizedBBList) {
for (Instr i : b.getInstrs()) {
if (i == excInstr) {
BasicBlock ensurerBB = cfg.getEnsurerBBFor(b);
return (ensurerBB == null) ? -1 : ensurerBB.getLabel().getTargetPC();
}
}
}
// SSS FIXME: Cannot happen! Throw runtime exception
LOG.error("Fell through looking for ensurer ipc for " + excInstr);
return -1;
}
/** Run any necessary passes to get the IR ready for compilation */
public Tuple<Instr[], Map<Integer, Label[]>> prepareForCompilation() {
// Build CFG and run compiler passes, if necessary
if (getCFG() == null) runCompilerPasses();
// Add this always since we dont re-JIT a previously
// JIT-ted closure. But, check if there are other
// smarts available to us and eliminate adding this
// code to every closure there is.
//
// Add a global ensure block to catch uncaught breaks
// and throw a LocalJumpError.
if (this instanceof IRClosure && ((IRClosure) this).addGEBForUncaughtBreaks()) {
this.relinearizeCFG = true;
}
try {
buildLinearization(); // FIXME: compiler passes should have done this
depends(linearization());
} catch (RuntimeException e) {
LOG.error("Error linearizing cfg: ", e);
CFG c = cfg();
LOG.error("\nGraph:\n" + c.toStringGraph());
LOG.error("\nInstructions:\n" + c.toStringInstrs());
throw e;
}
// Set up IPCs
// FIXME: Would be nice to collapse duplicate labels; for now, using Label[]
HashMap<Integer, Label[]> ipcLabelMap = new HashMap<Integer, Label[]>();
List<Instr> newInstrs = new ArrayList<Instr>();
int ipc = 0;
for (BasicBlock b : linearizedBBList) {
Label l = b.getLabel();
ipcLabelMap.put(ipc, catLabels(ipcLabelMap.get(ipc), l));
for (Instr i : b.getInstrs()) {
if (!(i instanceof ReceiveSelfInstr)) {
newInstrs.add(i);
ipc++;
}
}
}
return new Tuple<Instr[], Map<Integer, Label[]>>(
newInstrs.toArray(new Instr[newInstrs.size()]), ipcLabelMap);
}
public void setUpUseDefLocalVarMaps() {
definedLocalVars = new java.util.HashSet<Variable>();
usedLocalVars = new java.util.HashSet<Variable>();
for (BasicBlock bb : cfg().getBasicBlocks()) {
for (Instr i : bb.getInstrs()) {
for (Variable v : i.getUsedVariables()) {
if (v instanceof LocalVariable) usedLocalVars.add(v);
}
if (i instanceof ResultInstr) {
Variable v = ((ResultInstr) i).getResult();
if (v instanceof LocalVariable) definedLocalVars.add(v);
}
}
}
for (IRClosure cl : getClosures()) {
cl.setUpUseDefLocalVarMaps();
}
}
public void compute_MEET(Edge e, BasicBlock source, FlowGraphNode pred) {
// Ignore rescue entries -- everything is unboxed, as necessary.
if (!source.isRescueEntry()) {
inState.computeMEET(((UnboxableOpsAnalysisNode) pred).outState);
}
}
@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);
}
private void setupLabelPCs(HashMap<Label, Integer> labelIPCMap) {
for (BasicBlock b : linearizedBBList) {
Label l = b.getLabel();
l.setTargetPC(labelIPCMap.get(l));
}
}
