Mercurial > hg > graal-compiler
view graal/com.oracle.jvmci.code/src/com/oracle/jvmci/code/TypeCheckHints.java @ 21591:6c5327245831
LinearScan: fix intervals context.
author | Josef Eisl <josef.eisl@jku.at> |
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date | Fri, 29 May 2015 10:59:03 +0200 |
parents | 48c1ebd24120 |
children |
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/* * 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 com.oracle.jvmci.code; import com.oracle.jvmci.meta.JavaTypeProfile; import com.oracle.jvmci.meta.ResolvedJavaType; import com.oracle.jvmci.meta.Assumptions; import java.util.*; import com.oracle.jvmci.meta.Assumptions.AssumptionResult; import com.oracle.jvmci.meta.JavaTypeProfile.ProfiledType; /** * 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(ResolvedJavaType targetType, JavaTypeProfile profile, Assumptions assumptions, double minHintHitProbability, int maxHints) { this.profile = profile; if (targetType != null && !canHaveSubtype(targetType)) { exact = targetType; } else { if (assumptions != null) { AssumptionResult<ResolvedJavaType> leafConcreteSubtype = targetType == null ? null : targetType.findLeafConcreteSubtype(); if (leafConcreteSubtype != null) { assumptions.record(leafConcreteSubtype); exact = leafConcreteSubtype.getResult(); } else { exact = null; } } else { exact = null; } } Double[] hitProbability = {null}; this.hints = makeHints(targetType, profile, minHintHitProbability, maxHints, hitProbability); this.hintHitProbability = hitProbability[0]; } private static Hint[] makeHints(ResolvedJavaType 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.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; } /** * Determines if a given type can have subtypes other than itself. This analysis is purely * static; no assumptions are made. * * @return true if {@code type} can have subtypes */ public static boolean canHaveSubtype(ResolvedJavaType type) { return !type.getElementalType().isFinal(); } }