public OriginalValueSearch(ValueNode proxy) {
NodeWorkList worklist = proxy.graph().createNodeWorkList();
worklist.add(proxy);
for (Node node : worklist) {
if (node instanceof LimitedValueProxy) {
ValueNode originalValue = ((LimitedValueProxy) node).getOriginalNode();
if (!process(originalValue, worklist)) {
return;
}
} else if (node instanceof PhiNode) {
for (Node value : ((PhiNode) node).values()) {
if (!process((ValueNode) value, worklist)) {
return;
}
}
} else {
if (!process((ValueNode) node, null)) {
return;
}
}
}
}
/**
* Process a node as part of this search.
*
* @param node the next node encountered in the search
* @param worklist if non-null, {@code node} will be added to this list. Otherwise, {@code node}
* is treated as a candidate result.
* @return true if the search should continue, false if a definitive {@link #result} has been
* found
*/
private boolean process(ValueNode node, NodeWorkList worklist) {
if (node.isAlive()) {
if (worklist == null) {
if (result == null) {
// Initial candidate result: continue search
result = node;
} else if (result != node) {
// Conflicts with existing candidate: stop search with null result
result = null;
return false;
}
} else {
worklist.add(node);
}
}
return true;
}