Mercurial > hg > truffle
view graal/com.oracle.max.criutils/src/com/oracle/max/criutils/TypeCheckHints.java @ 5471:c9b8994b43d8
Merge.
author | Thomas Wuerthinger <thomas.wuerthinger@oracle.com> |
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date | Fri, 01 Jun 2012 16:32:05 +0200 |
parents | 2e9a5365dfb0 |
children | dc71b06d09f8 |
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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.max.criutils; import java.lang.reflect.*; import java.util.*; import com.oracle.max.cri.ci.*; import com.oracle.max.cri.ri.*; import com.oracle.max.cri.ri.RiTypeProfile.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 { private static final RiResolvedType[] NO_TYPES = {}; /** * If true, then {@link #types} contains the only possible 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. */ public final boolean exact; /** * The most likely types that the type check instruction will see. */ public final RiResolvedType[] types; /** * Derives hint information for use when generating the code for a type check instruction. * * @param type 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 the profiled types (up to * {@code maxHints}) is below this value, then {@link #types} will be null * @param maxHints the maximum length of {@link #types} */ public TypeCheckHints(RiResolvedType type, RiTypeProfile profile, CiAssumptions assumptions, double minHintHitProbability, int maxHints) { if (type != null && isFinalClass(type)) { types = new RiResolvedType[] {type}; exact = true; } else { RiResolvedType uniqueSubtype = type == null ? null : type.uniqueConcreteSubtype(); if (uniqueSubtype != null) { types = new RiResolvedType[] {uniqueSubtype}; if (assumptions != null) { assumptions.recordConcreteSubtype(type, uniqueSubtype); exact = true; } else { exact = false; } } else { exact = false; RiResolvedType[] hintTypes = NO_TYPES; RiTypeProfile typeProfile = profile; if (typeProfile != null) { double notRecordedTypes = typeProfile.getNotRecordedProbability(); ProfiledType[] ptypes = typeProfile.getTypes(); if (notRecordedTypes < (1D - minHintHitProbability) && ptypes != null && ptypes.length > 0) { hintTypes = new RiResolvedType[ptypes.length]; int hintCount = 0; double totalHintProbability = 0.0d; for (ProfiledType ptype : ptypes) { RiResolvedType hint = ptype.type; if (type != null && hint.isSubtypeOf(type)) { hintTypes[hintCount++] = hint; totalHintProbability += ptype.probability; } } if (totalHintProbability >= minHintHitProbability) { if (hintTypes.length != hintCount || hintCount > maxHints) { hintTypes = Arrays.copyOf(hintTypes, Math.min(maxHints, hintCount)); } } else { hintTypes = NO_TYPES; } } } this.types = hintTypes; } } } public static boolean isFinalClass(RiResolvedType type) { return Modifier.isFinal(type.accessFlags()) || (type.isArrayClass() && Modifier.isFinal(type.componentType().accessFlags())); } }