Mercurial > hg > graal-jvmci-8
view graal/com.oracle.graal.compiler.common/src/com/oracle/graal/compiler/common/type/AbstractObjectStamp.java @ 18476:2e2148013010
Move nonNull and alwaysNull flags up to AbstractPointerStamp.
author | Roland Schatz <roland.schatz@oracle.com> |
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date | Wed, 19 Nov 2014 16:52:54 +0100 |
parents | 2dc0d4dcb709 |
children | f91e40c4bb47 |
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/* * Copyright (c) 2012, 2014, 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.graal.compiler.common.type; import java.util.*; import com.oracle.graal.api.meta.*; /** * Type describing all pointers to Java objects. */ public abstract class AbstractObjectStamp extends AbstractPointerStamp { private final ResolvedJavaType type; private final boolean exactType; protected AbstractObjectStamp(ResolvedJavaType type, boolean exactType, boolean nonNull, boolean alwaysNull) { super(PointerType.Object, nonNull, alwaysNull); this.type = type; this.exactType = exactType; } protected abstract AbstractObjectStamp copyWith(ResolvedJavaType newType, boolean newExactType, boolean newNonNull, boolean newAlwaysNull); @Override public Stamp unrestricted() { return copyWith(null, false, false, false); } @Override public Stamp illegal() { return copyWith(null, true, true, false); } @Override public Stamp constant(Constant c, MetaAccessProvider meta) { JavaConstant jc = (JavaConstant) c; ResolvedJavaType constType = jc.isNull() ? null : meta.lookupJavaType(jc); return copyWith(constType, jc.isNonNull(), jc.isNonNull(), jc.isNull()); } @Override public boolean isLegal() { return !exactType || (type != null && (isConcreteType(type))); } @Override public Kind getStackKind() { return Kind.Object; } @Override public ResolvedJavaType javaType(MetaAccessProvider metaAccess) { if (type != null) { return type; } return metaAccess.lookupJavaType(Object.class); } public ResolvedJavaType type() { return type; } public boolean isExactType() { return exactType; } protected void appendString(StringBuilder str) { str.append(nonNull() ? "!" : "").append(exactType ? "#" : "").append(' ').append(type == null ? "-" : type.getName()).append(alwaysNull() ? " NULL" : ""); } @Override public Stamp meet(Stamp otherStamp) { if (this == otherStamp) { return this; } if (!isCompatible(otherStamp)) { return StampFactory.illegal(Kind.Illegal); } AbstractObjectStamp other = (AbstractObjectStamp) otherStamp; if (!isLegal()) { return other; } else if (!other.isLegal()) { return this; } ResolvedJavaType meetType; boolean meetExactType; boolean meetNonNull; boolean meetAlwaysNull; if (other.alwaysNull()) { meetType = type(); meetExactType = exactType; meetNonNull = false; meetAlwaysNull = alwaysNull(); } else if (alwaysNull()) { meetType = other.type(); meetExactType = other.exactType; meetNonNull = false; meetAlwaysNull = other.alwaysNull(); } else { meetType = meetTypes(type(), other.type()); meetExactType = exactType && other.exactType; if (meetExactType && type != null && other.type != null) { // meeting two valid exact types may result in a non-exact type meetExactType = Objects.equals(meetType, type) && Objects.equals(meetType, other.type); } meetNonNull = nonNull() && other.nonNull(); meetAlwaysNull = false; } if (Objects.equals(meetType, type) && meetExactType == exactType && meetNonNull == nonNull() && meetAlwaysNull == alwaysNull()) { return this; } else if (Objects.equals(meetType, other.type) && meetExactType == other.exactType && meetNonNull == other.nonNull() && meetAlwaysNull == other.alwaysNull()) { return other; } else { return copyWith(meetType, meetExactType, meetNonNull, meetAlwaysNull); } } @Override public Stamp join(Stamp otherStamp) { return join0(otherStamp, false); } /** * Returns the stamp representing the type of this stamp after a cast to the type represented by * the {@code to} stamp. While this is very similar to a {@link #join} operation, in the case * where both types are not obviously related, the cast operation will prefer the type of the * {@code to} stamp. This is necessary as long as ObjectStamps are not able to accurately * represent intersection types. * * For example when joining the {@link RandomAccess} type with the {@link AbstractList} type, * without intersection types, this would result in the most generic type ({@link Object} ). For * this reason, in some cases a {@code castTo} operation is preferable in order to keep at least * the {@link AbstractList} type. * * @param to the stamp this stamp should be casted to * @return This stamp casted to the {@code to} stamp */ public Stamp castTo(ObjectStamp to) { return join0(to, true); } private Stamp join0(Stamp otherStamp, boolean castToOther) { if (this == otherStamp) { return this; } if (!isCompatible(otherStamp)) { return StampFactory.illegal(Kind.Illegal); } AbstractObjectStamp other = (AbstractObjectStamp) otherStamp; if (!isLegal()) { return this; } else if (!other.isLegal()) { return other; } ResolvedJavaType joinType; boolean joinAlwaysNull = alwaysNull() || other.alwaysNull(); boolean joinNonNull = nonNull() || other.nonNull(); boolean joinExactType = exactType || other.exactType; if (Objects.equals(type, other.type)) { joinType = type; } else if (type == null && other.type == null) { joinType = null; } else if (type == null) { joinType = other.type; } else if (other.type == null) { joinType = type; } else { // both types are != null and different if (type.isAssignableFrom(other.type)) { joinType = other.type; if (exactType) { joinAlwaysNull = true; } } else if (other.type.isAssignableFrom(type)) { joinType = type; if (other.exactType) { joinAlwaysNull = true; } } else { if (castToOther) { joinType = other.type; joinExactType = other.exactType; } else { joinType = null; } if (joinExactType || (!type.isInterface() && !other.type.isInterface())) { joinAlwaysNull = true; } } } if (joinAlwaysNull) { joinType = null; joinExactType = false; } if (joinExactType && joinType == null) { return StampFactory.illegal(Kind.Object); } if (joinAlwaysNull && joinNonNull) { return StampFactory.illegal(Kind.Object); } else if (joinExactType && !isConcreteType(joinType)) { return StampFactory.illegal(Kind.Object); } if (Objects.equals(joinType, type) && joinExactType == exactType && joinNonNull == nonNull() && joinAlwaysNull == alwaysNull()) { return this; } else if (Objects.equals(joinType, other.type) && joinExactType == other.exactType && joinNonNull == other.nonNull() && joinAlwaysNull == other.alwaysNull()) { return other; } else { return copyWith(joinType, joinExactType, joinNonNull, joinAlwaysNull); } } public static boolean isConcreteType(ResolvedJavaType type) { return !(type.isAbstract() && !type.isArray()); } private static ResolvedJavaType meetTypes(ResolvedJavaType a, ResolvedJavaType b) { if (Objects.equals(a, b)) { return a; } else if (a == null || b == null) { return null; } else { return a.findLeastCommonAncestor(b); } } @Override public int hashCode() { final int prime = 31; int result = 1; result = prime * result + super.hashCode(); result = prime * result + (exactType ? 1231 : 1237); result = prime * result + ((type == null) ? 0 : type.hashCode()); return result; } @Override public boolean equals(Object obj) { if (this == obj) { return true; } if (obj == null || getClass() != obj.getClass()) { return false; } AbstractObjectStamp other = (AbstractObjectStamp) obj; if (exactType != other.exactType || !Objects.equals(type, other.type)) { return false; } return super.equals(other); } }