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.Debug;
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();
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 try (Debug.Scope s = Debug.scope("InlineGraph", graph)) {
96
97 ArrayList<Node> parameterUsages = replaceParamsWithMoreInformativeArguments(invoke, context);
98 if (parameterUsages != null) {
99 assert !parameterUsages.isEmpty() : "The caller didn't have more information about arguments after all";
100 canonicalizer.applyIncremental(graph, context, parameterUsages);
101 return true;
102 } else {
103 // TODO (chaeubl): if args are not more concrete, inlining should be avoided
104 // in most cases or we could at least use the previous graph size + invoke
105 // probability to check the inlining
106 return false;
107 }
108
109 } catch (Throwable e) {
110 throw Debug.handle(e);
111 }
112 }
113
114 private static boolean isArgMoreInformativeThanParam(ValueNode arg, ParameterNode param) {
115 return arg.isConstant() || canStampBeImproved(arg, param);
116 }
117
118 private static boolean canStampBeImproved(ValueNode arg, ParameterNode param) {
119 return improvedStamp(arg, param) != null;
120 }
121
122 private static Stamp improvedStamp(ValueNode arg, ParameterNode param) {
123 Stamp joinedStamp = param.stamp().join(arg.stamp());
124 if (joinedStamp == null || joinedStamp.equals(param.stamp())) {
125 return null;
126 }
127 return joinedStamp;
128 }
129
130 /**
131 * This method detects:
132 * <ul>
133 * <li>constants among the arguments to the <code>invoke</code></li>
134 * <li>arguments with more precise type than that declared by the corresponding parameter</li>
135 * </ul>
136 *
137 * <p>
138 * The corresponding parameters are updated to reflect the above information. Before doing so,
139 * their usages are added to <code>parameterUsages</code> for later incremental
140 * canonicalization.
141 * </p>
142 *
143 * @return null if no incremental canonicalization is need, a list of nodes for such
144 * canonicalization otherwise.
145 */
146 private ArrayList<Node> replaceParamsWithMoreInformativeArguments(final Invoke invoke, final HighTierContext context) {
147 NodeInputList<ValueNode> args = invoke.callTarget().arguments();
148 ArrayList<Node> parameterUsages = null;
149 List<ParameterNode> params = graph.getNodes(ParameterNode.TYPE).snapshot();
150 assert params.size() <= args.size();
151 /*
152 * param-nodes that aren't used (eg, as a result of canonicalization) don't occur in
153 * `params`. Thus, in general, the sizes of `params` and `args` don't always match. Still,
154 * it's always possible to pair a param-node with its corresponding arg-node using
155 * param.index() as index into `args`.
156 */
157 for (ParameterNode param : params) {
158 if (param.usages().isNotEmpty()) {
159 ValueNode arg = args.get(param.index());
160 if (arg.isConstant()) {
161 Constant constant = arg.asConstant();
162 parameterUsages = trackParameterUsages(param, parameterUsages);
163 // collect param usages before replacing the param
164 param.replaceAtUsagesAndDelete(graph.unique(
165 ConstantNode.forConstant(arg.stamp(), constant, ((ConstantNode) arg).getStableDimension(), ((ConstantNode) arg).isDefaultStable(), context.getMetaAccess())));
166 // param-node gone, leaving a gap in the sequence given by param.index()
167 } else {
168 Stamp impro = improvedStamp(arg, param);
169 if (impro != null) {
170 param.setStamp(impro);
171 parameterUsages = trackParameterUsages(param, parameterUsages);
172 } else {
173 assert !isArgMoreInformativeThanParam(arg, param);
174 }
175 }
176 }
177 }
178 assert (parameterUsages == null) || (!parameterUsages.isEmpty());
179 return parameterUsages;
180 }
181
182 private static ArrayList<Node> trackParameterUsages(ParameterNode param, ArrayList<Node> parameterUsages) {
183 ArrayList<Node> result = (parameterUsages == null) ? new ArrayList<>() : parameterUsages;
184 param.usages().snapshotTo(result);
185 return result;
186 }
187
188 /**
189 * This method builds the IR nodes for the given <code>method</code> and canonicalizes them.
190 * Provided profiling info is mature, the resulting graph is cached. The caller is responsible
191 * for cloning before modification.
192 * </p>
193 */
194 @SuppressWarnings("try")
195 private static StructuredGraph parseBytecodes(ResolvedJavaMethod method, HighTierContext context, CanonicalizerPhase canonicalizer, StructuredGraph caller) {
196 StructuredGraph newGraph = new StructuredGraph.Builder(caller.getOptions(), AllowAssumptions.ifNonNull(caller.getAssumptions())).method(method).build();
197 try (Debug.Scope s = Debug.scope("InlineGraph", newGraph)) {
198 if (!caller.isUnsafeAccessTrackingEnabled()) {
199 newGraph.disableUnsafeAccessTracking();
200 }
201 if (context.getGraphBuilderSuite() != null) {
202 context.getGraphBuilderSuite().apply(newGraph, context);
203 }
204 assert newGraph.start().next() != null : "graph needs to be populated by the GraphBuilderSuite " + method + ", " + method.canBeInlined();
205
206 new DeadCodeEliminationPhase(Optional).apply(newGraph);
207
208 canonicalizer.apply(newGraph, context);
209
210 return newGraph;
211 } catch (Throwable e) {
212 throw Debug.handle(e);
213 }
214 }
215
216 @Override
217 public int getNodeCount() {
218 return InliningUtil.getNodeCount(graph);
219 }
220
221 @Override
222 public Iterable<Invoke> getInvokes() {
223 return graph.getInvokes();
224 }
225
226 @Override
227 public double getProbability(Invoke invoke) {
228 return probabilites.applyAsDouble(invoke.asNode());
229 }
230
231 public StructuredGraph getGraph() {
232 return graph;
233 }
234 }