/*
* Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package org.graalvm.compiler.phases.common.inlining.info.elem;
import static org.graalvm.compiler.phases.common.DeadCodeEliminationPhase.Optionality.Optional;
import java.util.ArrayList;
import java.util.List;
import org.graalvm.compiler.core.common.type.Stamp;
import org.graalvm.compiler.debug.Debug;
import org.graalvm.compiler.graph.Node;
import org.graalvm.compiler.graph.NodeInputList;
import org.graalvm.compiler.nodes.ConstantNode;
import org.graalvm.compiler.nodes.Invoke;
import org.graalvm.compiler.nodes.ParameterNode;
import org.graalvm.compiler.nodes.StructuredGraph;
import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;
import org.graalvm.compiler.nodes.ValueNode;
import org.graalvm.compiler.phases.common.CanonicalizerPhase;
import org.graalvm.compiler.phases.common.DeadCodeEliminationPhase;
import org.graalvm.compiler.phases.common.inlining.InliningUtil;
import org.graalvm.compiler.phases.graph.FixedNodeProbabilityCache;
import org.graalvm.compiler.phases.tiers.HighTierContext;
import jdk.vm.ci.meta.Constant;
import jdk.vm.ci.meta.ResolvedJavaMethod;
/**
* <p>
* Represents a feasible concrete target for inlining, whose graph has been copied already and thus
* can be modified without affecting the original (usually cached) version.
* </p>
*
* <p>
* Instances of this class don't make sense in isolation but as part of an
* {@link org.graalvm.compiler.phases.common.inlining.info.InlineInfo InlineInfo}.
* </p>
*
* @see org.graalvm.compiler.phases.common.inlining.walker.InliningData#moveForward()
* @see org.graalvm.compiler.phases.common.inlining.walker.CallsiteHolderExplorable
*/
public class InlineableGraph implements Inlineable {
private final StructuredGraph graph;
private FixedNodeProbabilityCache probabilites = new FixedNodeProbabilityCache();
public InlineableGraph(final ResolvedJavaMethod method, final Invoke invoke, final HighTierContext context, CanonicalizerPhase canonicalizer) {
StructuredGraph original = getOriginalGraph(method, context, canonicalizer, invoke.asNode().graph(), invoke.bci());
// TODO copying the graph is only necessary if it is modified or if it contains any invokes
this.graph = (StructuredGraph) original.copy();
specializeGraphToArguments(invoke, context, canonicalizer);
}
/**
* This method looks up in a cache the graph for the argument, if not found bytecode is parsed.
* The graph thus obtained is returned, ie the caller is responsible for cloning before
* modification.
*/
private static StructuredGraph getOriginalGraph(final ResolvedJavaMethod method, final HighTierContext context, CanonicalizerPhase canonicalizer, StructuredGraph caller, int callerBci) {
StructuredGraph result = InliningUtil.getIntrinsicGraph(context.getReplacements(), method, callerBci);
if (result != null) {
return result;
}
return parseBytecodes(method, context, canonicalizer, caller);
}
/**
* @return true iff one or more parameters <code>newGraph</code> were specialized to account for
* a constant argument, or an argument with a more specific stamp.
*/
@SuppressWarnings("try")
private boolean specializeGraphToArguments(final Invoke invoke, final HighTierContext context, CanonicalizerPhase canonicalizer) {
try (Debug.Scope s = Debug.scope("InlineGraph", graph)) {
ArrayList<Node> parameterUsages = replaceParamsWithMoreInformativeArguments(invoke, context);
if (parameterUsages != null) {
assert !parameterUsages.isEmpty() : "The caller didn't have more information about arguments after all";
canonicalizer.applyIncremental(graph, context, parameterUsages);
return true;
} else {
// TODO (chaeubl): if args are not more concrete, inlining should be avoided
// in most cases or we could at least use the previous graph size + invoke
// probability to check the inlining
return false;
}
} catch (Throwable e) {
throw Debug.handle(e);
}
}
private static boolean isArgMoreInformativeThanParam(ValueNode arg, ParameterNode param) {
return arg.isConstant() || canStampBeImproved(arg, param);
}
private static boolean canStampBeImproved(ValueNode arg, ParameterNode param) {
return improvedStamp(arg, param) != null;
}
private static Stamp improvedStamp(ValueNode arg, ParameterNode param) {
Stamp joinedStamp = param.stamp().join(arg.stamp());
if (joinedStamp == null || joinedStamp.equals(param.stamp())) {
return null;
}
return joinedStamp;
}
/**
* This method detects:
* <ul>
* <li>constants among the arguments to the <code>invoke</code></li>
* <li>arguments with more precise type than that declared by the corresponding parameter</li>
* </ul>
*
* <p>
* The corresponding parameters are updated to reflect the above information. Before doing so,
* their usages are added to <code>parameterUsages</code> for later incremental
* canonicalization.
* </p>
*
* @return null if no incremental canonicalization is need, a list of nodes for such
* canonicalization otherwise.
*/
private ArrayList<Node> replaceParamsWithMoreInformativeArguments(final Invoke invoke, final HighTierContext context) {
NodeInputList<ValueNode> args = invoke.callTarget().arguments();
ArrayList<Node> parameterUsages = null;
List<ParameterNode> params = graph.getNodes(ParameterNode.TYPE).snapshot();
assert params.size() <= args.size();
/*
* param-nodes that aren't used (eg, as a result of canonicalization) don't occur in
* `params`. Thus, in general, the sizes of `params` and `args` don't always match. Still,
* it's always possible to pair a param-node with its corresponding arg-node using
* param.index() as index into `args`.
*/
for (ParameterNode param : params) {
if (param.usages().isNotEmpty()) {
ValueNode arg = args.get(param.index());
if (arg.isConstant()) {
Constant constant = arg.asConstant();
parameterUsages = trackParameterUsages(param, parameterUsages);
// collect param usages before replacing the param
param.replaceAtUsagesAndDelete(graph.unique(
ConstantNode.forConstant(arg.stamp(), constant, ((ConstantNode) arg).getStableDimension(), ((ConstantNode) arg).isDefaultStable(), context.getMetaAccess())));
// param-node gone, leaving a gap in the sequence given by param.index()
} else {
Stamp impro = improvedStamp(arg, param);
if (impro != null) {
param.setStamp(impro);
parameterUsages = trackParameterUsages(param, parameterUsages);
} else {
assert !isArgMoreInformativeThanParam(arg, param);
}
}
}
}
assert (parameterUsages == null) || (!parameterUsages.isEmpty());
return parameterUsages;
}
private static ArrayList<Node> trackParameterUsages(ParameterNode param, ArrayList<Node> parameterUsages) {
ArrayList<Node> result = (parameterUsages == null) ? new ArrayList<>() : parameterUsages;
param.usages().snapshotTo(result);
return result;
}
/**
* This method builds the IR nodes for the given <code>method</code> and canonicalizes them.
* Provided profiling info is mature, the resulting graph is cached. The caller is responsible
* for cloning before modification.
* </p>
*/
@SuppressWarnings("try")
private static StructuredGraph parseBytecodes(ResolvedJavaMethod method, HighTierContext context, CanonicalizerPhase canonicalizer, StructuredGraph caller) {
StructuredGraph newGraph = new StructuredGraph.Builder(caller.getOptions(), AllowAssumptions.ifNonNull(caller.getAssumptions())).method(method).build();
try (Debug.Scope s = Debug.scope("InlineGraph", newGraph)) {
if (!caller.isUnsafeAccessTrackingEnabled()) {
newGraph.disableUnsafeAccessTracking();
}
if (context.getGraphBuilderSuite() != null) {
context.getGraphBuilderSuite().apply(newGraph, context);
}
assert newGraph.start().next() != null : "graph needs to be populated by the GraphBuilderSuite " + method + ", " + method.canBeInlined();
new DeadCodeEliminationPhase(Optional).apply(newGraph);
canonicalizer.apply(newGraph, context);
return newGraph;
} catch (Throwable e) {
throw Debug.handle(e);
}
}
@Override
public int getNodeCount() {
return InliningUtil.getNodeCount(graph);
}
@Override
public Iterable<Invoke> getInvokes() {
return graph.getInvokes();
}
@Override
public double getProbability(Invoke invoke) {
return probabilites.applyAsDouble(invoke.asNode());
}
public StructuredGraph getGraph() {
return graph;
}
}