Exemplo n.º 1
0
 private static void killEnd(AbstractEndNode end) {
   MergeNode merge = end.merge();
   if (merge != null) {
     merge.removeEnd(end);
     StructuredGraph graph = end.graph();
     if (merge instanceof LoopBeginNode && merge.forwardEndCount() == 0) { // dead loop
       for (PhiNode phi : merge.phis().snapshot()) {
         propagateKill(phi);
       }
       LoopBeginNode begin = (LoopBeginNode) merge;
       // disconnect and delete loop ends & loop exits
       for (LoopEndNode loopend : begin.loopEnds().snapshot()) {
         loopend.predecessor().replaceFirstSuccessor(loopend, null);
         loopend.safeDelete();
       }
       begin.removeExits();
       FixedNode loopBody = begin.next();
       if (loopBody != null) { // for small infinite loops, the body may be killed while
         // killing the loop ends
         killCFG(loopBody);
       }
       begin.safeDelete();
     } else if (merge instanceof LoopBeginNode
         && ((LoopBeginNode) merge).loopEnds().isEmpty()) { // not
       // a
       // loop
       // anymore
       graph.reduceDegenerateLoopBegin((LoopBeginNode) merge);
     } else if (merge.phiPredecessorCount() == 1) { // not a merge anymore
       graph.reduceTrivialMerge(merge);
     }
   }
 }
Exemplo n.º 2
0
 public void removeSplitPropagate(
     ControlSplitNode node, AbstractBeginNode survivingSuccessor, SimplifierTool tool) {
   assert node != null;
   assert node.hasNoUsages();
   assert survivingSuccessor != null;
   List<Node> snapshot = node.successors().snapshot();
   node.clearSuccessors();
   node.replaceAtPredecessor(survivingSuccessor);
   node.safeDelete();
   for (Node successor : snapshot) {
     if (successor != null && successor.isAlive()) {
       if (successor != survivingSuccessor) {
         GraphUtil.killCFG(successor, tool);
       }
     }
   }
 }
Exemplo n.º 3
0
 public static void killCFG(FixedNode node) {
   assert node.isAlive();
   if (node instanceof AbstractEndNode) {
     // We reached a control flow end.
     AbstractEndNode end = (AbstractEndNode) node;
     killEnd(end);
   } else {
     // Normal control flow node.
     /*
      * We do not take a successor snapshot because this iterator supports concurrent
      * modifications as long as they do not change the size of the successor list. Not
      * taking a snapshot allows us to see modifications to other branches that may happen
      * while processing one branch.
      */
     for (Node successor : node.successors()) {
       killCFG((FixedNode) successor);
     }
   }
   propagateKill(node);
 }
  private void visitDeoptBegin(
      AbstractBeginNode deoptBegin,
      DeoptimizationAction deoptAction,
      DeoptimizationReason deoptReason,
      JavaConstant speculation,
      StructuredGraph graph) {
    if (deoptBegin.predecessor() instanceof AbstractBeginNode) {
      /* Walk up chains of LoopExitNodes to the "real" BeginNode that leads to deoptimization. */
      visitDeoptBegin(
          (AbstractBeginNode) deoptBegin.predecessor(),
          deoptAction,
          deoptReason,
          speculation,
          graph);
      return;
    }

    if (deoptBegin instanceof AbstractMergeNode) {
      AbstractMergeNode mergeNode = (AbstractMergeNode) deoptBegin;
      Debug.log("Visiting %s", mergeNode);
      FixedNode next = mergeNode.next();
      while (mergeNode.isAlive()) {
        AbstractEndNode end = mergeNode.forwardEnds().first();
        AbstractBeginNode newBeginNode = findBeginNode(end);
        visitDeoptBegin(newBeginNode, deoptAction, deoptReason, speculation, graph);
      }
      assert next.isAlive();
      AbstractBeginNode newBeginNode = findBeginNode(next);
      visitDeoptBegin(newBeginNode, deoptAction, deoptReason, speculation, graph);
      return;
    } else if (deoptBegin.predecessor() instanceof IfNode) {
      IfNode ifNode = (IfNode) deoptBegin.predecessor();
      AbstractBeginNode otherBegin = ifNode.trueSuccessor();
      LogicNode conditionNode = ifNode.condition();
      FixedGuardNode guard =
          graph.add(
              new FixedGuardNode(
                  conditionNode,
                  deoptReason,
                  deoptAction,
                  speculation,
                  deoptBegin == ifNode.trueSuccessor()));
      FixedWithNextNode pred = (FixedWithNextNode) ifNode.predecessor();
      AbstractBeginNode survivingSuccessor;
      if (deoptBegin == ifNode.trueSuccessor()) {
        survivingSuccessor = ifNode.falseSuccessor();
      } else {
        survivingSuccessor = ifNode.trueSuccessor();
      }
      graph.removeSplitPropagate(ifNode, survivingSuccessor);

      Node newGuard = guard;
      if (survivingSuccessor instanceof LoopExitNode) {
        newGuard = ProxyNode.forGuard(guard, (LoopExitNode) survivingSuccessor, graph);
      }
      survivingSuccessor.replaceAtUsages(InputType.Guard, newGuard);

      Debug.log(
          "Converting deopt on %-5s branch of %s to guard for remaining branch %s.",
          deoptBegin == ifNode.trueSuccessor() ? "true" : "false", ifNode, otherBegin);
      FixedNode next = pred.next();
      pred.setNext(guard);
      guard.setNext(next);
      survivingSuccessor.simplify(simplifierTool);
      return;
    }

    // We could not convert the control split - at least cut off control flow after the split.
    FixedWithNextNode deoptPred = deoptBegin;
    FixedNode next = deoptPred.next();

    if (!(next instanceof DeoptimizeNode)) {
      DeoptimizeNode newDeoptNode =
          graph.add(new DeoptimizeNode(deoptAction, deoptReason, speculation));
      deoptPred.setNext(newDeoptNode);
      assert deoptPred == newDeoptNode.predecessor();
      GraphUtil.killCFG(next);
    }
  }
Exemplo n.º 5
0
 public static void killCFG(Node node) {
   killCFG(node, null);
 }
Exemplo n.º 6
0
 public void deleteBranch(Node branch) {
   branch.predecessor().replaceFirstSuccessor(branch, null);
   GraphUtil.killCFG(branch, this);
 }