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comparison graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/InstanceOfSnippets.java @ 10069:abb9d3a26025

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an instanceof instruction lowers to a deoptimize-on-hint-miss snippet only if its profile indicates a miss (of a hint type) occurs an order of magnitude less than the compilation threshold
author Doug Simon <doug.simon@oracle.com>
date Mon, 17 Jun 2013 17:55:19 +0200
parents 0b30da13d86b
children e04f128d719c
comparison
equal deleted inserted replaced
10068:529570e20aff 10069:abb9d3a26025
57 * Cliff Click and John Rose. 57 * Cliff Click and John Rose.
58 */ 58 */
59 public class InstanceOfSnippets implements Snippets { 59 public class InstanceOfSnippets implements Snippets {
60 60
61 /** 61 /**
62 * Gets the minimum required probability of a profiled instanceof hitting one the profiled types
63 * for use of the {@linkplain #instanceofWithProfile deoptimizing} snippet. The value is
64 * computed to be an order of magnitude greater than the configured compilation threshold. For
65 * example, if a method is compiled after being interpreted 10000 times, the deoptimizing
66 * snippet will only be used for an instanceof if its profile indicates that less than 1 in
67 * 100000 executions are for an object whose type is not one of the top N profiled types (where
68 * {@code N == } {@link GraalOptions#InstanceOfMaxHints}).
69 */
70 public static double hintHitProbabilityThresholdForDeoptimizingSnippet() {
71 return 1.0D - (1.0D / (graalRuntime().getConfig().compileThreshold * 10));
72 }
73
74 /**
62 * A test against a set of hints derived from a profile with very close to 100% precise coverage 75 * A test against a set of hints derived from a profile with very close to 100% precise coverage
63 * of seen types. This snippet deoptimizes on hint miss paths. 76 * of seen types. This snippet deoptimizes on hint miss paths.
64 * 77 *
65 * @see GraalOptions#InstanceOfFullCoverageSpeculationThreshold 78 * @see #hintHitProbabilityThresholdForDeoptimizingSnippet()
66 */ 79 */
67 @Snippet 80 @Snippet
68 public static Object instanceofWithProfile(Object object, @VarargsParameter Word[] hints, @VarargsParameter boolean[] hintIsPositive, Object trueValue, Object falseValue, 81 public static Object instanceofWithProfile(Object object, @VarargsParameter Word[] hints, @VarargsParameter boolean[] hintIsPositive, Object trueValue, Object falseValue,
69 @ConstantParameter boolean checkNull, @ConstantParameter boolean nullSeen) { 82 @ConstantParameter boolean checkNull, @ConstantParameter boolean nullSeen) {
70 if (probability(NOT_FREQUENT_PROBABILITY, checkNull && object == null)) { 83 if (probability(NOT_FREQUENT_PROBABILITY, checkNull && object == null)) {
194 TypeCheckHints hintInfo = new TypeCheckHints(instanceOf.type(), instanceOf.profile(), tool.assumptions(), InstanceOfMinHintHitProbability.getValue(), InstanceOfMaxHints.getValue()); 207 TypeCheckHints hintInfo = new TypeCheckHints(instanceOf.type(), instanceOf.profile(), tool.assumptions(), InstanceOfMinHintHitProbability.getValue(), InstanceOfMaxHints.getValue());
195 final HotSpotResolvedObjectType type = (HotSpotResolvedObjectType) instanceOf.type(); 208 final HotSpotResolvedObjectType type = (HotSpotResolvedObjectType) instanceOf.type();
196 ConstantNode hub = ConstantNode.forConstant(type.klass(), runtime, instanceOf.graph()); 209 ConstantNode hub = ConstantNode.forConstant(type.klass(), runtime, instanceOf.graph());
197 210
198 Arguments args; 211 Arguments args;
199 if (hintInfo.hintHitProbability >= InstanceOfFullCoverageSpeculationThreshold.getValue()) { 212
213 if (hintInfo.hintHitProbability >= hintHitProbabilityThresholdForDeoptimizingSnippet()) {
200 Hints hints = createHints(hintInfo, runtime, false, hub.graph()); 214 Hints hints = createHints(hintInfo, runtime, false, hub.graph());
201 args = new Arguments(instanceofWithProfile); 215 args = new Arguments(instanceofWithProfile);
202 args.add("object", object); 216 args.add("object", object);
203 args.addVarargs("hints", Word.class, StampFactory.forKind(wordKind()), hints.hubs); 217 args.addVarargs("hints", Word.class, StampFactory.forKind(wordKind()), hints.hubs);
204 args.addVarargs("hintIsPositive", boolean.class, StampFactory.forKind(Kind.Boolean), hints.isPositive); 218 args.addVarargs("hintIsPositive", boolean.class, StampFactory.forKind(Kind.Boolean), hints.isPositive);
220 args.addVarargs("hintIsPositive", boolean.class, StampFactory.forKind(Kind.Boolean), hints.isPositive); 234 args.addVarargs("hintIsPositive", boolean.class, StampFactory.forKind(Kind.Boolean), hints.isPositive);
221 } 235 }
222 args.add("trueValue", replacer.trueValue); 236 args.add("trueValue", replacer.trueValue);
223 args.add("falseValue", replacer.falseValue); 237 args.add("falseValue", replacer.falseValue);
224 args.addConst("checkNull", !object.stamp().nonNull()); 238 args.addConst("checkNull", !object.stamp().nonNull());
225 if (hintInfo.hintHitProbability >= InstanceOfFullCoverageSpeculationThreshold.getValue()) { 239 if (hintInfo.hintHitProbability >= hintHitProbabilityThresholdForDeoptimizingSnippet()) {
226 args.addConst("nullSeen", hintInfo.profile.getNullSeen() != TriState.FALSE); 240 args.addConst("nullSeen", hintInfo.profile.getNullSeen() != TriState.FALSE);
227 } 241 }
228 return args; 242 return args;
229 243
230 } else { 244 } else {