/**
* For one or more `invoke` arguments, flow-sensitive information may suggest their narrowing or
* simplification. In those cases, a new {@link com.oracle.graal.nodes.java.MethodCallTargetNode
* MethodCallTargetNode} is prepared just for this callsite, consuming reduced arguments.
*
* <p>Specializing the {@link com.oracle.graal.nodes.java.MethodCallTargetNode
* MethodCallTargetNode} as described above may enable two optimizations:
*
* <ul>
* <li>devirtualization of an {@link com.oracle.graal.nodes.CallTargetNode.InvokeKind#Interface}
* or {@link com.oracle.graal.nodes.CallTargetNode.InvokeKind#Virtual} callsite
* (devirtualization made possible after narrowing the type of the receiver)
* <li>(future work) actual-argument-aware inlining, ie, to specialize callees on the types of
* arguments other than the receiver (examples: multi-methods, the inlining problem, lambdas
* as arguments).
* </ul>
*
* <p>Precondition: inputs haven't been deverbosified yet.
*/
private void visitInvoke(Invoke invoke) {
if (invoke.asNode().stamp() instanceof IllegalStamp) {
return; // just to be safe
}
boolean isMethodCallTarget = invoke.callTarget() instanceof MethodCallTargetNode;
if (!isMethodCallTarget) {
return;
}
FlowUtil.replaceInPlace(
invoke.asNode(),
invoke.callTarget(),
deverbosifyInputsCopyOnWrite((MethodCallTargetNode) invoke.callTarget()));
MethodCallTargetNode callTarget = (MethodCallTargetNode) invoke.callTarget();
if (callTarget.invokeKind() != CallTargetNode.InvokeKind.Interface
&& callTarget.invokeKind() != CallTargetNode.InvokeKind.Virtual) {
return;
}
ValueNode receiver = callTarget.receiver();
if (receiver == null) {
return;
}
if (!FlowUtil.hasLegalObjectStamp(receiver)) {
return;
}
Witness w = state.typeInfo(receiver);
ResolvedJavaType type;
ResolvedJavaType stampType = StampTool.typeOrNull(receiver);
if (w == null || w.cluelessAboutType()) {
// can't improve on stamp but wil try to devirtualize anyway
type = stampType;
} else {
type = FlowUtil.tighten(w.type(), stampType);
}
if (type == null) {
return;
}
ResolvedJavaMethod method =
type.resolveMethod(callTarget.targetMethod(), invoke.getContextType());
if (method == null) {
return;
}
if (method.canBeStaticallyBound() || Modifier.isFinal(type.getModifiers())) {
metricMethodResolved.increment();
callTarget.setInvokeKind(CallTargetNode.InvokeKind.Special);
callTarget.setTargetMethod(method);
}
}
/**
* Gets an approximate source code location for a node if possible.
*
* @return the StackTraceElements if an approximate source location is found, null otherwise
*/
public static StackTraceElement[] approxSourceStackTraceElement(Node node) {
ArrayList<StackTraceElement> elements = new ArrayList<>();
Node n = node;
while (n != null) {
if (n instanceof MethodCallTargetNode) {
elements.add(((MethodCallTargetNode) n).targetMethod().asStackTraceElement(-1));
n = ((MethodCallTargetNode) n).invoke().asNode();
}
if (n instanceof StateSplit) {
FrameState state = ((StateSplit) n).stateAfter();
while (state != null) {
ResolvedJavaMethod method = state.method();
if (method != null) {
elements.add(method.asStackTraceElement(state.bci - 1));
}
state = state.outerFrameState();
}
break;
}
n = n.predecessor();
}
return elements.toArray(new StackTraceElement[elements.size()]);
}