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