001/* 002 * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved. 003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 004 * 005 * This code is free software; you can redistribute it and/or modify it 006 * under the terms of the GNU General Public License version 2 only, as 007 * published by the Free Software Foundation. 008 * 009 * This code is distributed in the hope that it will be useful, but WITHOUT 010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 011 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 012 * version 2 for more details (a copy is included in the LICENSE file that 013 * accompanied this code). 014 * 015 * You should have received a copy of the GNU General Public License version 016 * 2 along with this work; if not, write to the Free Software Foundation, 017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 018 * 019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 020 * or visit www.oracle.com if you need additional information or have any 021 * questions. 022 */ 023package com.oracle.graal.compiler.common.type; 024 025import jdk.internal.jvmci.meta.*; 026 027/** 028 * Abstract base class of all pointer types. 029 */ 030public abstract class AbstractPointerStamp extends Stamp { 031 032 private final boolean nonNull; 033 private final boolean alwaysNull; 034 035 protected AbstractPointerStamp(boolean nonNull, boolean alwaysNull) { 036 this.nonNull = nonNull; 037 this.alwaysNull = alwaysNull; 038 } 039 040 public boolean nonNull() { 041 assert !this.isEmpty() || nonNull; 042 return nonNull; 043 } 044 045 public boolean alwaysNull() { 046 return alwaysNull; 047 } 048 049 protected abstract AbstractPointerStamp copyWith(boolean newNonNull, boolean newAlwaysNull); 050 051 @Override 052 public int hashCode() { 053 final int prime = 31; 054 int result = 1; 055 result = prime * result + (alwaysNull ? 1231 : 1237); 056 result = prime * result + (nonNull ? 1231 : 1237); 057 return result; 058 } 059 060 @Override 061 public Stamp join(Stamp stamp) { 062 AbstractPointerStamp other = (AbstractPointerStamp) stamp; 063 boolean joinNonNull = this.nonNull || other.nonNull; 064 boolean joinAlwaysNull = this.alwaysNull || other.alwaysNull; 065 if (joinNonNull && joinAlwaysNull) { 066 return empty(); 067 } else { 068 return copyWith(joinNonNull, joinAlwaysNull); 069 } 070 } 071 072 @Override 073 public Stamp improveWith(Stamp other) { 074 return join(other); 075 } 076 077 @Override 078 public Stamp meet(Stamp stamp) { 079 AbstractPointerStamp other = (AbstractPointerStamp) stamp; 080 boolean meetNonNull = this.nonNull && other.nonNull; 081 boolean meetAlwaysNull = this.alwaysNull && other.alwaysNull; 082 return copyWith(meetNonNull, meetAlwaysNull); 083 } 084 085 @Override 086 public Stamp unrestricted() { 087 return copyWith(false, false); 088 } 089 090 @Override 091 public boolean equals(Object obj) { 092 if (this == obj) { 093 return true; 094 } 095 if (obj == null || getClass() != obj.getClass()) { 096 return false; 097 } 098 AbstractPointerStamp other = (AbstractPointerStamp) obj; 099 return this.alwaysNull == other.alwaysNull && this.nonNull == other.nonNull; 100 } 101 102 @Override 103 public Constant asConstant() { 104 if (alwaysNull) { 105 return JavaConstant.NULL_POINTER; 106 } else { 107 return null; 108 } 109 } 110 111 @Override 112 public Kind getStackKind() { 113 return Kind.Illegal; 114 } 115}