Mercurial > hg > truffle
view graal/com.oracle.max.criutils/src/com/oracle/max/criutils/TypeCheckHints.java @ 5563:6a2671066204
added NewInstanceSnippets for lowering NewInstanceNodes (currently disabled by default)
added Word type and WordTypeRewriterPhase to support programming against machine word values in snippets without duplicating the code for 32 and 64 bit platforms
added GraphUtil.approxSourceLocation() utility method for getting an approximate source code location for a node
author | Doug Simon <doug.simon@oracle.com> |
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date | Mon, 11 Jun 2012 15:39:57 +0200 |
parents | b6617d13ea44 |
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.max.criutils; import java.lang.reflect.*; import java.util.*; import com.oracle.graal.api.code.*; import com.oracle.graal.api.meta.*; import com.oracle.graal.api.meta.JavaTypeProfile.*; /** * 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 ResolvedJavaType[] 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 ResolvedJavaType[] 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(ResolvedJavaType type, JavaTypeProfile profile, Assumptions assumptions, double minHintHitProbability, int maxHints) { if (type != null && isFinalClass(type)) { types = new ResolvedJavaType[] {type}; exact = true; } else { ResolvedJavaType uniqueSubtype = type == null ? null : type.uniqueConcreteSubtype(); if (uniqueSubtype != null) { types = new ResolvedJavaType[] {uniqueSubtype}; if (assumptions != null) { assumptions.recordConcreteSubtype(type, uniqueSubtype); exact = true; } else { exact = false; } } else { exact = false; ResolvedJavaType[] hintTypes = NO_TYPES; JavaTypeProfile typeProfile = profile; if (typeProfile != null) { double notRecordedTypes = typeProfile.getNotRecordedProbability(); ProfiledType[] ptypes = typeProfile.getTypes(); if (notRecordedTypes < (1D - minHintHitProbability) && ptypes != null && ptypes.length > 0) { hintTypes = new ResolvedJavaType[ptypes.length]; int hintCount = 0; double totalHintProbability = 0.0d; for (ProfiledType ptype : ptypes) { ResolvedJavaType 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(ResolvedJavaType type) { return Modifier.isFinal(type.accessFlags()) || (type.isArrayClass() && Modifier.isFinal(type.componentType().accessFlags())); } }