| /* |
| * Copyright (c) 2012, 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.nodes; |
| |
| import java.util.Arrays; |
| |
| import org.graalvm.compiler.core.common.type.TypeReference; |
| |
| import jdk.vm.ci.meta.Assumptions; |
| import jdk.vm.ci.meta.JavaTypeProfile; |
| import jdk.vm.ci.meta.JavaTypeProfile.ProfiledType; |
| import jdk.vm.ci.meta.ResolvedJavaType; |
| |
| /** |
| * Utility for deriving hint types for a type check instruction (e.g. checkcast or instanceof) based |
| * on the target type of the check and any profiling information available for the instruction. |
| */ |
| public class TypeCheckHints { |
| |
| /** |
| * A receiver type profiled in a type check instruction. |
| */ |
| public static class Hint { |
| |
| /** |
| * A type seen while profiling a type check instruction. |
| */ |
| public final ResolvedJavaType type; |
| |
| /** |
| * Specifies if {@link #type} is a sub-type of the checked type. |
| */ |
| public final boolean positive; |
| |
| Hint(ResolvedJavaType type, boolean positive) { |
| this.type = type; |
| this.positive = positive; |
| } |
| } |
| |
| private static final Hint[] NO_HINTS = {}; |
| |
| /** |
| * If non-null, then this is the only type that could pass the type check because the target of |
| * the type check is a final class or has been speculated to be a final class and this value is |
| * the only concrete subclass of the target type. |
| */ |
| public final ResolvedJavaType exact; |
| |
| /** |
| * The most likely types that the type check instruction will see. |
| */ |
| public final Hint[] hints; |
| |
| /** |
| * The profile from which this information was derived. |
| */ |
| public final JavaTypeProfile profile; |
| |
| /** |
| * The total probability that the type check will hit one of the types in {@link #hints}. |
| */ |
| public final double hintHitProbability; |
| |
| /** |
| * Derives hint information for use when generating the code for a type check instruction. |
| * |
| * @param targetType the target type of the type check |
| * @param profile the profiling information available for the instruction (if any) |
| * @param assumptions the object in which speculations are recorded. This is null if |
| * speculations are not supported. |
| * @param minHintHitProbability if the probability that the type check will hit one of the |
| * profiled types (up to {@code maxHints}) is below this value, then {@link #hints} |
| * will be null |
| * @param maxHints the maximum length of {@link #hints} |
| */ |
| public TypeCheckHints(TypeReference targetType, JavaTypeProfile profile, Assumptions assumptions, double minHintHitProbability, int maxHints) { |
| this.profile = profile; |
| if (targetType != null && targetType.isExact()) { |
| exact = targetType.getType(); |
| } else { |
| exact = null; |
| } |
| Double[] hitProbability = {null}; |
| this.hints = makeHints(targetType, profile, minHintHitProbability, maxHints, hitProbability); |
| this.hintHitProbability = hitProbability[0]; |
| } |
| |
| private static Hint[] makeHints(TypeReference targetType, JavaTypeProfile profile, double minHintHitProbability, int maxHints, Double[] hitProbability) { |
| double hitProb = 0.0d; |
| Hint[] hintsBuf = NO_HINTS; |
| if (profile != null) { |
| double notRecordedTypes = profile.getNotRecordedProbability(); |
| ProfiledType[] ptypes = profile.getTypes(); |
| if (notRecordedTypes < (1D - minHintHitProbability) && ptypes != null && ptypes.length > 0) { |
| hintsBuf = new Hint[ptypes.length]; |
| int hintCount = 0; |
| for (ProfiledType ptype : ptypes) { |
| if (targetType != null) { |
| ResolvedJavaType hintType = ptype.getType(); |
| hintsBuf[hintCount++] = new Hint(hintType, targetType.getType().isAssignableFrom(hintType)); |
| hitProb += ptype.getProbability(); |
| } |
| if (hintCount == maxHints) { |
| break; |
| } |
| } |
| if (hitProb >= minHintHitProbability) { |
| if (hintsBuf.length != hintCount || hintCount > maxHints) { |
| hintsBuf = Arrays.copyOf(hintsBuf, Math.min(maxHints, hintCount)); |
| } |
| } else { |
| hintsBuf = NO_HINTS; |
| hitProb = 0.0d; |
| } |
| } |
| } |
| hitProbability[0] = hitProb; |
| return hintsBuf; |
| } |
| } |