001 /*
002 * Copyright 2010-2015 JetBrains s.r.o.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017 package org.jetbrains.kotlin.codegen.optimization.common;
018
019 import org.jetbrains.annotations.NotNull;
020 import org.jetbrains.annotations.Nullable;
021 import org.jetbrains.org.objectweb.asm.Opcodes;
022 import org.jetbrains.org.objectweb.asm.Type;
023 import org.jetbrains.org.objectweb.asm.tree.AbstractInsnNode;
024 import org.jetbrains.org.objectweb.asm.tree.LdcInsnNode;
025 import org.jetbrains.org.objectweb.asm.tree.analysis.AnalyzerException;
026 import org.jetbrains.org.objectweb.asm.tree.analysis.BasicInterpreter;
027 import org.jetbrains.org.objectweb.asm.tree.analysis.BasicValue;
028
029 public class OptimizationBasicInterpreter extends BasicInterpreter {
030 private static final BasicValue BOOLEAN_VALUE = new BasicValue(Type.BOOLEAN_TYPE);
031 private static final BasicValue CHAR_VALUE = new BasicValue(Type.CHAR_TYPE);
032 private static final BasicValue BYTE_VALUE = new BasicValue(Type.BYTE_TYPE);
033 private static final BasicValue SHORT_VALUE = new BasicValue(Type.SHORT_TYPE);
034
035 @Override
036 @Nullable
037 public BasicValue newValue(@Nullable Type type) {
038 if (type == null) {
039 return super.newValue(null);
040 }
041
042 switch (type.getSort()) {
043 case Type.VOID:
044 return null;
045 case Type.BOOLEAN:
046 return BOOLEAN_VALUE;
047 case Type.CHAR:
048 return CHAR_VALUE;
049 case Type.BYTE:
050 return BYTE_VALUE;
051 case Type.SHORT:
052 return SHORT_VALUE;
053 case Type.OBJECT:
054 return new BasicValue(type);
055 default:
056 return super.newValue(type);
057 }
058 }
059
060 @Override
061 public BasicValue newOperation(@NotNull AbstractInsnNode insn) throws AnalyzerException {
062 if (insn.getOpcode() == Opcodes.LDC) {
063 Object cst = ((LdcInsnNode) insn).cst;
064
065 if (cst instanceof Long) {
066 return BasicValue.LONG_VALUE;
067 }
068
069 if (cst instanceof Boolean ||
070 cst instanceof Integer ||
071 cst instanceof Short ||
072 cst instanceof Byte ||
073 cst instanceof Character) {
074 return BasicValue.INT_VALUE;
075 }
076
077 if (cst instanceof Float) {
078 return BasicValue.FLOAT_VALUE;
079 }
080
081 if (cst instanceof Double) {
082 return BasicValue.DOUBLE_VALUE;
083 }
084 }
085
086 return super.newOperation(insn);
087 }
088
089 @NotNull
090 @Override
091 public BasicValue merge(
092 @NotNull BasicValue v, @NotNull BasicValue w
093 ) {
094 if (!v.equals(w)) {
095 if (v == BasicValue.UNINITIALIZED_VALUE || w == BasicValue.UNINITIALIZED_VALUE) {
096 return BasicValue.UNINITIALIZED_VALUE;
097 }
098
099 // if merge of two references then `lub` is java/lang/Object
100 // arrays also are BasicValues with reference type's
101 if (v.getType().getSort() == Type.OBJECT && w.getType().getSort() == Type.OBJECT) {
102 return BasicValue.REFERENCE_VALUE;
103 }
104
105 assert v.getType().getSort() != Type.ARRAY && w.getType().getSort() != Type.ARRAY : "There should not be arrays";
106
107 // if merge of something can be stored in int var (int, char, boolean, byte, character)
108 if (v.getType().getOpcode(Opcodes.ISTORE) == Opcodes.ISTORE &&
109 w.getType().getOpcode(Opcodes.ISTORE) == Opcodes.ISTORE) {
110 return BasicValue.INT_VALUE;
111 }
112
113 return BasicValue.UNINITIALIZED_VALUE;
114 }
115 return v;
116 }
117 }