1 /*
2 * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23 package org.graalvm.compiler.phases.common.inlining.info.elem;
24
25 import static org.graalvm.compiler.core.common.CompilationIdentifier.INVALID_COMPILATION_ID;
26 import static org.graalvm.compiler.core.common.GraalOptions.UseGraalInstrumentation;
27 import static org.graalvm.compiler.phases.common.DeadCodeEliminationPhase.Optionality.Optional;
28
29 import java.util.ArrayList;
30 import java.util.List;
31
32 import org.graalvm.compiler.core.common.type.Stamp;
33 import org.graalvm.compiler.debug.Debug;
34 import org.graalvm.compiler.graph.Node;
35 import org.graalvm.compiler.graph.NodeInputList;
36 import org.graalvm.compiler.nodes.ConstantNode;
37 import org.graalvm.compiler.nodes.Invoke;
38 import org.graalvm.compiler.nodes.ParameterNode;
39 import org.graalvm.compiler.nodes.StructuredGraph;
40 import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;
41 import org.graalvm.compiler.nodes.ValueNode;
42 import org.graalvm.compiler.phases.common.CanonicalizerPhase;
43 import org.graalvm.compiler.phases.common.DeadCodeEliminationPhase;
44 import org.graalvm.compiler.phases.common.inlining.InliningUtil;
45 import org.graalvm.compiler.phases.common.instrumentation.ExtractInstrumentationPhase;
46 import org.graalvm.compiler.phases.graph.FixedNodeProbabilityCache;
47 import org.graalvm.compiler.phases.tiers.HighTierContext;
48
49 import jdk.vm.ci.meta.Constant;
50 import jdk.vm.ci.meta.ResolvedJavaMethod;
51
52 /**
53 * <p>
54 * Represents a feasible concrete target for inlining, whose graph has been copied already and thus
55 * can be modified without affecting the original (usually cached) version.
56 * </p>
57 *
58 * <p>
59 * Instances of this class don't make sense in isolation but as part of an
60 * {@link org.graalvm.compiler.phases.common.inlining.info.InlineInfo InlineInfo}.
61 * </p>
62 *
63 * @see org.graalvm.compiler.phases.common.inlining.walker.InliningData#moveForward()
64 * @see org.graalvm.compiler.phases.common.inlining.walker.CallsiteHolderExplorable
65 */
66 public class InlineableGraph implements Inlineable {
67
68 private final StructuredGraph graph;
69
70 private FixedNodeProbabilityCache probabilites = new FixedNodeProbabilityCache();
71
72 public InlineableGraph(final ResolvedJavaMethod method, final Invoke invoke, final HighTierContext context, CanonicalizerPhase canonicalizer) {
73 StructuredGraph original = getOriginalGraph(method, context, canonicalizer, invoke.asNode().graph(), invoke.bci());
74 // TODO copying the graph is only necessary if it is modified or if it contains any invokes
75 this.graph = (StructuredGraph) original.copy();
76 specializeGraphToArguments(invoke, context, canonicalizer);
77 }
78
79 /**
80 * This method looks up in a cache the graph for the argument, if not found bytecode is parsed.
81 * The graph thus obtained is returned, ie the caller is responsible for cloning before
82 * modification.
83 */
84 private static StructuredGraph getOriginalGraph(final ResolvedJavaMethod method, final HighTierContext context, CanonicalizerPhase canonicalizer, StructuredGraph caller, int callerBci) {
85 StructuredGraph result = InliningUtil.getIntrinsicGraph(context.getReplacements(), method, callerBci);
86 if (result != null) {
87 return result;
88 }
89 return parseBytecodes(method, context, canonicalizer, caller);
90 }
91
92 /**
93 * @return true iff one or more parameters <code>newGraph</code> were specialized to account for
94 * a constant argument, or an argument with a more specific stamp.
95 */
96 @SuppressWarnings("try")
97 private boolean specializeGraphToArguments(final Invoke invoke, final HighTierContext context, CanonicalizerPhase canonicalizer) {
98 try (Debug.Scope s = Debug.scope("InlineGraph", graph)) {
99
100 ArrayList<Node> parameterUsages = replaceParamsWithMoreInformativeArguments(invoke, context);
101 if (parameterUsages != null) {
102 assert !parameterUsages.isEmpty() : "The caller didn't have more information about arguments after all";
103 canonicalizer.applyIncremental(graph, context, parameterUsages);
104 return true;
105 } else {
106 // TODO (chaeubl): if args are not more concrete, inlining should be avoided
107 // in most cases or we could at least use the previous graph size + invoke
108 // probability to check the inlining
109 return false;
110 }
111
112 } catch (Throwable e) {
113 throw Debug.handle(e);
114 }
115 }
116
117 private static boolean isArgMoreInformativeThanParam(ValueNode arg, ParameterNode param) {
118 return arg.isConstant() || canStampBeImproved(arg, param);
119 }
120
121 private static boolean canStampBeImproved(ValueNode arg, ParameterNode param) {
122 return improvedStamp(arg, param) != null;
123 }
124
125 private static Stamp improvedStamp(ValueNode arg, ParameterNode param) {
126 Stamp joinedStamp = param.stamp().join(arg.stamp());
127 if (joinedStamp == null || joinedStamp.equals(param.stamp())) {
128 return null;
129 }
130 return joinedStamp;
131 }
132
133 /**
134 * This method detects:
135 * <ul>
136 * <li>constants among the arguments to the <code>invoke</code></li>
137 * <li>arguments with more precise type than that declared by the corresponding parameter</li>
138 * </ul>
139 *
140 * <p>
141 * The corresponding parameters are updated to reflect the above information. Before doing so,
142 * their usages are added to <code>parameterUsages</code> for later incremental
143 * canonicalization.
144 * </p>
145 *
146 * @return null if no incremental canonicalization is need, a list of nodes for such
147 * canonicalization otherwise.
148 */
149 private ArrayList<Node> replaceParamsWithMoreInformativeArguments(final Invoke invoke, final HighTierContext context) {
150 NodeInputList<ValueNode> args = invoke.callTarget().arguments();
151 ArrayList<Node> parameterUsages = null;
152 List<ParameterNode> params = graph.getNodes(ParameterNode.TYPE).snapshot();
153 assert params.size() <= args.size();
154 /*
155 * param-nodes that aren't used (eg, as a result of canonicalization) don't occur in
156 * `params`. Thus, in general, the sizes of `params` and `args` don't always match. Still,
157 * it's always possible to pair a param-node with its corresponding arg-node using
158 * param.index() as index into `args`.
159 */
160 for (ParameterNode param : params) {
161 if (param.usages().isNotEmpty()) {
162 ValueNode arg = args.get(param.index());
163 if (arg.isConstant()) {
164 Constant constant = arg.asConstant();
165 parameterUsages = trackParameterUsages(param, parameterUsages);
166 // collect param usages before replacing the param
167 param.replaceAtUsagesAndDelete(graph.unique(
168 ConstantNode.forConstant(arg.stamp(), constant, ((ConstantNode) arg).getStableDimension(), ((ConstantNode) arg).isDefaultStable(), context.getMetaAccess())));
169 // param-node gone, leaving a gap in the sequence given by param.index()
170 } else {
171 Stamp impro = improvedStamp(arg, param);
172 if (impro != null) {
173 param.setStamp(impro);
174 parameterUsages = trackParameterUsages(param, parameterUsages);
175 } else {
176 assert !isArgMoreInformativeThanParam(arg, param);
177 }
178 }
179 }
180 }
181 assert (parameterUsages == null) || (!parameterUsages.isEmpty());
182 return parameterUsages;
183 }
184
185 private static ArrayList<Node> trackParameterUsages(ParameterNode param, ArrayList<Node> parameterUsages) {
186 ArrayList<Node> result = (parameterUsages == null) ? new ArrayList<>() : parameterUsages;
187 param.usages().snapshotTo(result);
188 return result;
189 }
190
191 /**
192 * This method builds the IR nodes for the given <code>method</code> and canonicalizes them.
193 * Provided profiling info is mature, the resulting graph is cached. The caller is responsible
194 * for cloning before modification.
195 * </p>
196 */
197 @SuppressWarnings("try")
198 private static StructuredGraph parseBytecodes(ResolvedJavaMethod method, HighTierContext context, CanonicalizerPhase canonicalizer, StructuredGraph caller) {
199 StructuredGraph newGraph = new StructuredGraph(method, AllowAssumptions.from(caller.getAssumptions() != null), INVALID_COMPILATION_ID);
200 try (Debug.Scope s = Debug.scope("InlineGraph", newGraph)) {
201 if (!caller.isUnsafeAccessTrackingEnabled()) {
202 newGraph.disableUnsafeAccessTracking();
203 }
204 if (context.getGraphBuilderSuite() != null) {
205 context.getGraphBuilderSuite().apply(newGraph, context);
206 }
207 assert newGraph.start().next() != null : "graph needs to be populated by the GraphBuilderSuite " + method + ", " + method.canBeInlined();
208
209 if (UseGraalInstrumentation.getValue()) {
210 new ExtractInstrumentationPhase().apply(newGraph, context);
211 }
212 new DeadCodeEliminationPhase(Optional).apply(newGraph);
213
214 canonicalizer.apply(newGraph, context);
215
216 return newGraph;
217 } catch (Throwable e) {
218 throw Debug.handle(e);
219 }
220 }
221
222 @Override
223 public int getNodeCount() {
224 return InliningUtil.getNodeCount(graph);
225 }
226
227 @Override
228 public Iterable<Invoke> getInvokes() {
229 return graph.getInvokes();
230 }
231
232 @Override
233 public double getProbability(Invoke invoke) {
234 return probabilites.applyAsDouble(invoke.asNode());
235 }
236
237 public StructuredGraph getGraph() {
238 return graph;
239 }
240 }