private void processFixedGuardAndMerge(
     FixedGuardNode fixedGuard,
     PhaseContext context,
     CompareNode compare,
     ValueNode x,
     ValuePhiNode xPhi,
     ValueNode y,
     ValuePhiNode yPhi,
     AbstractMergeNode merge) {
   List<EndNode> mergePredecessors = merge.cfgPredecessors().snapshot();
   for (int i = 0; i < mergePredecessors.size(); ++i) {
     AbstractEndNode mergePredecessor = mergePredecessors.get(i);
     if (!mergePredecessor.isAlive()) {
       break;
     }
     Constant xs;
     if (xPhi == null) {
       xs = x.asConstant();
     } else {
       xs = xPhi.valueAt(mergePredecessor).asConstant();
     }
     Constant ys;
     if (yPhi == null) {
       ys = y.asConstant();
     } else {
       ys = yPhi.valueAt(mergePredecessor).asConstant();
     }
     if (xs != null
         && ys != null
         && compare
                 .condition()
                 .foldCondition(xs, ys, context.getConstantReflection(), compare.unorderedIsTrue())
             == fixedGuard.isNegated()) {
       visitDeoptBegin(
           AbstractBeginNode.prevBegin(mergePredecessor),
           fixedGuard.getAction(),
           fixedGuard.getReason(),
           fixedGuard.getSpeculation(),
           fixedGuard.graph());
     }
   }
 }
  @Override
  protected void run(final StructuredGraph graph, PhaseContext context) {
    assert graph.hasValueProxies() : "ConvertDeoptimizeToGuardPhase always creates proxies";
    if (graph.getNodes(DeoptimizeNode.TYPE).isEmpty()) {
      return;
    }
    for (DeoptimizeNode d : graph.getNodes(DeoptimizeNode.TYPE)) {
      assert d.isAlive();
      visitDeoptBegin(
          AbstractBeginNode.prevBegin(d), d.action(), d.reason(), d.getSpeculation(), graph);
    }

    if (context != null) {
      for (FixedGuardNode fixedGuard : graph.getNodes(FixedGuardNode.TYPE)) {
        trySplitFixedGuard(fixedGuard, context);
      }
    }

    new DeadCodeEliminationPhase(Optional).apply(graph);
  }
  private void processFixedGuardAndPhis(
      FixedGuardNode fixedGuard,
      PhaseContext context,
      CompareNode compare,
      ValueNode x,
      ValuePhiNode xPhi,
      ValueNode y,
      ValuePhiNode yPhi) {
    AbstractBeginNode pred = AbstractBeginNode.prevBegin(fixedGuard);
    if (pred instanceof AbstractMergeNode) {
      AbstractMergeNode merge = (AbstractMergeNode) pred;
      if (xPhi != null && xPhi.merge() != merge) {
        return;
      }
      if (yPhi != null && yPhi.merge() != merge) {
        return;
      }

      processFixedGuardAndMerge(fixedGuard, context, compare, x, xPhi, y, yPhi, merge);
    }
  }
    @SuppressWarnings("try")
    private AnchoringNode process(
        final Block b, final NodeBitMap activeGuards, final AnchoringNode startAnchor) {

      final LoweringToolImpl loweringTool =
          new LoweringToolImpl(context, startAnchor, activeGuards, b.getBeginNode());

      // Lower the instructions of this block.
      List<Node> nodes = schedule.nodesFor(b);
      for (Node node : nodes) {

        if (node.isDeleted()) {
          // This case can happen when previous lowerings deleted nodes.
          continue;
        }

        // Cache the next node to be able to reconstruct the previous of the next node
        // after lowering.
        FixedNode nextNode = null;
        if (node instanceof FixedWithNextNode) {
          nextNode = ((FixedWithNextNode) node).next();
        } else {
          nextNode = loweringTool.lastFixedNode().next();
        }

        if (node instanceof Lowerable) {
          Collection<Node> unscheduledUsages = null;
          assert (unscheduledUsages = getUnscheduledUsages(node)) != null;
          Mark preLoweringMark = node.graph().getMark();
          try (DebugCloseable s = node.graph().withNodeContext(node)) {
            ((Lowerable) node).lower(loweringTool);
          }
          if (loweringTool.guardAnchor.asNode().isDeleted()) {
            // TODO nextNode could be deleted but this is not currently supported
            assert nextNode.isAlive();
            loweringTool.guardAnchor = AbstractBeginNode.prevBegin(nextNode);
          }
          assert checkPostNodeLowering(node, loweringTool, preLoweringMark, unscheduledUsages);
        }

        if (!nextNode.isAlive()) {
          // can happen when the rest of the block is killed by lowering
          // (e.g. by an unconditional deopt)
          break;
        } else {
          Node nextLastFixed = nextNode.predecessor();
          if (!(nextLastFixed instanceof FixedWithNextNode)) {
            // insert begin node, to have a valid last fixed for next lowerable node.
            // This is about lowering a FixedWithNextNode to a control split while this
            // FixedWithNextNode is followed by some kind of BeginNode.
            // For example the when a FixedGuard followed by a loop exit is lowered to a
            // control-split + deopt.
            AbstractBeginNode begin = node.graph().add(new BeginNode());
            nextLastFixed.replaceFirstSuccessor(nextNode, begin);
            begin.setNext(nextNode);
            nextLastFixed = begin;
          }
          loweringTool.setLastFixedNode((FixedWithNextNode) nextLastFixed);
        }
      }
      return loweringTool.getCurrentGuardAnchor();
    }