private static Block calcBlockForUsage(
     Node node, Node usage, Block startBlock, NodeMap<Block> currentNodeMap) {
   assert !(node instanceof PhiNode);
   Block currentBlock = startBlock;
   if (usage instanceof PhiNode) {
     // An input to a PhiNode is used at the end of the predecessor block that
     // corresponds to the PhiNode input. One PhiNode can use an input multiple times.
     PhiNode phi = (PhiNode) usage;
     AbstractMergeNode merge = phi.merge();
     Block mergeBlock = currentNodeMap.get(merge);
     for (int i = 0; i < phi.valueCount(); ++i) {
       if (phi.valueAt(i) == node) {
         Block otherBlock = mergeBlock.getPredecessors()[i];
         currentBlock = AbstractControlFlowGraph.commonDominatorTyped(currentBlock, otherBlock);
       }
     }
   } else if (usage instanceof AbstractBeginNode) {
     AbstractBeginNode abstractBeginNode = (AbstractBeginNode) usage;
     if (abstractBeginNode instanceof StartNode) {
       currentBlock =
           AbstractControlFlowGraph.commonDominatorTyped(
               currentBlock, currentNodeMap.get(abstractBeginNode));
     } else {
       Block otherBlock = currentNodeMap.get(abstractBeginNode).getDominator();
       currentBlock = AbstractControlFlowGraph.commonDominatorTyped(currentBlock, otherBlock);
     }
   } else {
     // All other types of usages: Put the input into the same block as the usage.
     Block otherBlock = currentNodeMap.get(usage);
     currentBlock = AbstractControlFlowGraph.commonDominatorTyped(currentBlock, otherBlock);
   }
   return currentBlock;
 }
 private static void processStackPhi(NodeStack stack, PhiNode phiNode) {
   AbstractMergeNode merge = phiNode.merge();
   for (int i = 0; i < merge.forwardEndCount(); ++i) {
     Node input = phiNode.valueAt(i);
     if (input != null) {
       stack.push(input);
     }
   }
 }
 /**
  * The {@link com.oracle.graal.nodes.AbstractEndNode} at the end of the current code path
  * contributes values to {@link com.oracle.graal.nodes.PhiNode}s. Now is a good time to {@link
  * EquationalReasoner#deverbosify(com.oracle.graal.graph.Node) EquationalReasoner#deverbosify}
  * those values.
  *
  * <p>Precondition: inputs haven't been deverbosified yet.
  */
 private void visitAbstractEndNode(AbstractEndNode endNode) {
   MergeNode merge = endNode.merge();
   for (PhiNode phi : merge.phis()) {
     if (phi instanceof ValuePhiNode && phi.getKind() == Kind.Object) {
       assert phi.verify();
       int index = merge.phiPredecessorIndex(endNode);
       ValueNode original = phi.valueAt(index);
       ValueNode reduced = (ValueNode) reasoner.deverbosify(original);
       if (reduced != original) {
         phi.setValueAt(index, reduced);
         // `original` if unused will be removed in finished()
       }
     }
   }
 }
Exemple #4
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  public static void checkRedundantPhi(PhiNode phiNode) {
    if (phiNode.isDeleted() || phiNode.valueCount() == 1) {
      return;
    }

    ValueNode singleValue = phiNode.singleValue();
    if (singleValue != null) {
      Collection<PhiNode> phiUsages = phiNode.usages().filter(PhiNode.class).snapshot();
      Collection<ProxyNode> proxyUsages = phiNode.usages().filter(ProxyNode.class).snapshot();
      phiNode.graph().replaceFloating(phiNode, singleValue);
      for (PhiNode phi : phiUsages) {
        checkRedundantPhi(phi);
      }
      for (ProxyNode proxy : proxyUsages) {
        checkRedundantProxy(proxy);
      }
    }
  }
    private void scheduleEarliestIterative(
        BlockMap<List<Node>> blockToNodes,
        NodeMap<Block> nodeToBlock,
        NodeBitMap visited,
        StructuredGraph graph,
        boolean immutableGraph) {

      BitSet floatingReads = new BitSet(cfg.getBlocks().length);

      // Add begin nodes as the first entry and set the block for phi nodes.
      for (Block b : cfg.getBlocks()) {
        AbstractBeginNode beginNode = b.getBeginNode();
        ArrayList<Node> nodes = new ArrayList<>();
        nodeToBlock.set(beginNode, b);
        nodes.add(beginNode);
        blockToNodes.put(b, nodes);

        if (beginNode instanceof AbstractMergeNode) {
          AbstractMergeNode mergeNode = (AbstractMergeNode) beginNode;
          for (PhiNode phi : mergeNode.phis()) {
            nodeToBlock.set(phi, b);
          }
        } else if (beginNode instanceof LoopExitNode) {
          LoopExitNode loopExitNode = (LoopExitNode) beginNode;
          for (ProxyNode proxy : loopExitNode.proxies()) {
            nodeToBlock.set(proxy, b);
          }
        }
      }

      NodeStack stack = new NodeStack();

      // Start analysis with control flow ends.
      Block[] reversePostOrder = cfg.reversePostOrder();
      for (int j = reversePostOrder.length - 1; j >= 0; --j) {
        Block b = reversePostOrder[j];
        FixedNode endNode = b.getEndNode();
        if (isFixedEnd(endNode)) {
          stack.push(endNode);
          nodeToBlock.set(endNode, b);
        }
      }

      processStack(cfg, blockToNodes, nodeToBlock, visited, floatingReads, stack);

      // Visit back input edges of loop phis.
      boolean changed;
      boolean unmarkedPhi;
      do {
        changed = false;
        unmarkedPhi = false;
        for (LoopBeginNode loopBegin : graph.getNodes(LoopBeginNode.TYPE)) {
          for (PhiNode phi : loopBegin.phis()) {
            if (visited.isMarked(phi)) {
              for (int i = 0; i < loopBegin.getLoopEndCount(); ++i) {
                Node node = phi.valueAt(i + loopBegin.forwardEndCount());
                if (node != null && !visited.isMarked(node)) {
                  changed = true;
                  stack.push(node);
                  processStack(cfg, blockToNodes, nodeToBlock, visited, floatingReads, stack);
                }
              }
            } else {
              unmarkedPhi = true;
            }
          }
        }

        /*
         * the processing of one loop phi could have marked a previously checked loop phi,
         * therefore this needs to be iterative.
         */
      } while (unmarkedPhi && changed);

      // Check for dead nodes.
      if (!immutableGraph && visited.getCounter() < graph.getNodeCount()) {
        for (Node n : graph.getNodes()) {
          if (!visited.isMarked(n)) {
            n.clearInputs();
            n.markDeleted();
          }
        }
      }

      // Add end nodes as the last nodes in each block.
      for (Block b : cfg.getBlocks()) {
        FixedNode endNode = b.getEndNode();
        if (isFixedEnd(endNode)) {
          if (endNode != b.getBeginNode()) {
            addNode(blockToNodes, b, endNode);
          }
        }
      }

      if (!floatingReads.isEmpty()) {
        for (Block b : cfg.getBlocks()) {
          if (floatingReads.get(b.getId())) {
            resortEarliestWithinBlock(b, blockToNodes, nodeToBlock, visited);
          }
        }
      }

      assert MemoryScheduleVerification.check(cfg.getStartBlock(), blockToNodes);
    }