1 /* 2 * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 package org.graalvm.compiler.core.common.type; 24 25 import jdk.vm.ci.meta.Constant; 26 import jdk.vm.ci.meta.JavaConstant; 27 import jdk.vm.ci.meta.JavaKind; 28 29 /** 30 * Abstract base class of all pointer types. 31 */ 32 public abstract class AbstractPointerStamp extends Stamp { 33 34 private final boolean nonNull; 35 private final boolean alwaysNull; 36 37 protected AbstractPointerStamp(boolean nonNull, boolean alwaysNull) { 38 this.nonNull = nonNull; 39 this.alwaysNull = alwaysNull; 40 } 41 42 public boolean nonNull() { 43 assert !this.isEmpty() || nonNull; 44 return nonNull; 45 } 46 47 public boolean alwaysNull() { 48 return alwaysNull; 49 } 50 51 protected abstract AbstractPointerStamp copyWith(boolean newNonNull, boolean newAlwaysNull); 52 53 @Override 54 public int hashCode() { 55 final int prime = 31; 56 int result = 1; 57 result = prime * result + (alwaysNull ? 1231 : 1237); 58 result = prime * result + (nonNull ? 1231 : 1237); 59 return result; 60 } 61 62 @Override 63 public Stamp join(Stamp stamp) { 64 AbstractPointerStamp other = (AbstractPointerStamp) stamp; 65 boolean joinNonNull = this.nonNull || other.nonNull; 66 boolean joinAlwaysNull = this.alwaysNull || other.alwaysNull; 67 if (joinNonNull && joinAlwaysNull) { 68 return empty(); 69 } else { 70 return copyWith(joinNonNull, joinAlwaysNull); 71 } 72 } 73 74 @Override 75 public Stamp improveWith(Stamp other) { 76 return join(other); 77 } 78 79 @Override 80 public Stamp meet(Stamp stamp) { 81 AbstractPointerStamp other = (AbstractPointerStamp) stamp; 82 boolean meetNonNull = this.nonNull && other.nonNull; 83 boolean meetAlwaysNull = this.alwaysNull && other.alwaysNull; 84 return copyWith(meetNonNull, meetAlwaysNull); 85 } 86 87 @Override 88 public Stamp unrestricted() { 89 return copyWith(false, false); 90 } 91 92 @Override 93 public boolean equals(Object obj) { 94 if (this == obj) { 95 return true; 96 } 97 if (obj == null || getClass() != obj.getClass()) { 98 return false; 99 } 100 AbstractPointerStamp other = (AbstractPointerStamp) obj; 101 return this.alwaysNull == other.alwaysNull && this.nonNull == other.nonNull; 102 } 103 104 @Override 105 public Constant asConstant() { 106 if (alwaysNull) { 107 return JavaConstant.NULL_POINTER; 108 } else { 109 return null; 110 } 111 } 112 113 @Override 114 public JavaKind getStackKind() { 115 return JavaKind.Illegal; 116 } 117 }