Initial commit

2026-03-13 21:43:42 +08:00 · 2023-07-19 18:06:38 +08:00
commit ff0fcd92bd
249 changed files with 7676 additions and 0 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -0,0 +1,38 @@
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### IntelliJ IDEA ###
+.idea/modules.xml
+.idea/jarRepositories.xml
+.idea/compiler.xml
+.idea/libraries/
+*.iws
+*.iml
+*.ipr
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store
--- a/README.md
+++ b/README.md
@@ -0,0 +1,64 @@
+# haidnorJVM
+使用 Java17 编写的 Java 虚拟机
+
+## 意义  
+1. 纸上得来终觉浅，绝知此事要躬行。只学习 JVM 机制和理论，很多时候任然觉得缺乏那种大彻大悟之感  
+2. 使用简单的方式实现 JVM，用于学习理解 JVM 运行原理
+
+## 主要技术选型
+* [Java 17](https://www.oracle.com/java/technologies/javase/jdk17-archive-downloads.html)
+* [Apache Commons BCEL](https://commons.apache.org/proper/commons-bcel/)
+* [Apache Commons CLI](https://commons.apache.org/proper/commons-cli/)
+
+# 实现功能与局限性
+* 支持基本数据类型数学运算
+* 支持循环、条件结构代码
+* 支持创建对象，访问对象
+* 支持多态
+* 支持访问静态方法
+* 不支持多线程
+* 垃圾回收依靠宿主 JVM
+
+# 快速体验
+## 你需要准备什么
+1. 集成开发环境 (IDE)。你可以选择包括 IntelliJ IDEA、Spring Tools、Visual Studio Code 或 Eclipse 等等
+2. JDK 17。并配置 JAVA_HOME
+3. JDK 8。强烈推荐! haidnorJVM 的主要目标是运行 Java8 本版的字节码文件。(haidnorVM 没有强制要求字节码文件是 Java8 版本)
+4. Maven
+
+## 配置 haidnorJVM
+### 配置日志输出级别
+修改 `simplelogger.properties` 文件中的内容。配置日志输出级别，一般使用 `debug`、`info`
+
+### 配置 rt.jar
+修改 `haidnorJVM.properties` 文件中的内容。配置 rt.jar 的绝对路径，例如`rt.jar=D:/Program Files/Java/jdk1.8.0_361/jre/lib/rt.jar`
+
+## 运行单元测试用例
+打开 test 目录下的 `haidnor.jvm.test.TestJVM` 类文件。 这是 haidnorJVM 功能的主要测试类。 里面的测试方法可以解析并加载一些class字节码文件。
+```java
+@Test
+public void test_LSUB() throws Exception {
+    runMainClass(LSUB.class);
+}
+```
+例如以上代码会加载 LSUB.class 类在 target 目录下的字节码文件，然后使用 haidnorJVM 运行其中的 main 函数。你可以使用打断点的方式看到 haidnorJVM 是如何解释运行 Java 字节码的。   
+值得注意的是，这种方式编译运行的字节码文件是基于 java17 版本的。
+
+## 运行 .class 文件
+1. 使用 maven 命令将项目编译打包，得到 `haidnorJVM-1.0.jar` 文件
+2. 编写一个简单的程序，例如以下代码
+   ```java
+   public class HelloWorld {
+      public static void main(String[] args) {
+        System.out.println("HelloWorld");
+      }
+   }
+   ```
+3. 编译代码，得到 HelloWorld.class 文件。（推荐使用 JDK8 进行编译）
+4. 使用 haidnorJVM 运行程序。执行命令 `java -jar haidnorJVM-1.0-SNAPSHOT.jar -class R:\HelloWorld.class`。注意需要 class 文件的绝对路径
+
+## 运行 .jar 文件
+开发中...
+
+# 联系作者
+个人微信账号: haidnor (请备注 "JVM")
--- a/pom.xml
+++ b/pom.xml
@@ -0,0 +1,86 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>haindor.vm</groupId>
+    <artifactId>haidnorJVM</artifactId>
+    <version>1.0</version>
+
+    <properties>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <dependencies>
+        <!-- https://mvnrepository.com/artifact/commons-cli/commons-cli -->
+        <dependency>
+            <groupId>commons-cli</groupId>
+            <artifactId>commons-cli</artifactId>
+            <version>1.5.0</version>
+        </dependency>
+
+        <!-- https://mvnrepository.com/artifact/org.apache.bcel/bcel -->
+        <dependency>
+            <groupId>org.apache.bcel</groupId>
+            <artifactId>bcel</artifactId>
+            <version>6.7.0</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>1.18.26</version>
+        </dependency>
+
+        <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+            <version>2.0.7</version>
+        </dependency>
+
+        <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-simple -->
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-simple</artifactId>
+            <version>2.0.7</version>
+        </dependency>
+
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.1</version>
+            <scope>test</scope>
+        </dependency>
+
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <version>2.3</version>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                        <configuration>
+                            <transformers>
+                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+                                    <mainClass>haidnor.jvm.Main</mainClass>
+                                </transformer>
+                            </transformers>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>
--- a/src/main/java/haidnor/jvm/Main.java
+++ b/src/main/java/haidnor/jvm/Main.java
@@ -0,0 +1,48 @@
+package haidnor.jvm;
+
+import haidnor.jvm.classloader.ClassLoader;
+import haidnor.jvm.core.JavaExecutionEngine;
+import haidnor.jvm.rtda.heap.Klass;
+import haidnor.jvm.rtda.heap.KlassMethod;
+import haidnor.jvm.rtda.metaspace.Metaspace;
+import haidnor.jvm.runtime.JvmThread;
+import haidnor.jvm.util.JavaClassUtil;
+import haidnor.jvm.util.JvmThreadHolder;
+import lombok.SneakyThrows;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.commons.cli.*;
+
+@Slf4j
+public class Main {
+
+    @SneakyThrows
+    public static void main(String[] args) {
+        Option jarOption = new Option("jar", true, "运行 jar 程序");
+        Option classOption = new Option("class", true, "运行 .class 字节码文件");
+
+        OptionGroup optionGroup = new OptionGroup();
+        optionGroup.addOption(jarOption).addOption(classOption);
+
+        Options options = new Options();
+        options.addOptionGroup(optionGroup);
+
+        CommandLineParser parser = new DefaultParser();
+        CommandLine cmd = parser.parse(options, args);
+
+        if (cmd.hasOption("jar")) {
+            String path = cmd.getOptionValue("jar");
+            // TODO
+        }
+        if (cmd.hasOption("class")) {
+            String path = cmd.getOptionValue("class");
+            ClassLoader bootClassLoader = new ClassLoader("ApplicationClassLoader");
+            Klass mainMeteKlass = bootClassLoader.loadClassWithAbsolutePath(path);
+            KlassMethod mainKlassMethod = JavaClassUtil.getMainMethod(mainMeteKlass);
+            Metaspace.registerJavaClass(mainMeteKlass);
+            JvmThreadHolder.set(new JvmThread());
+
+            JavaExecutionEngine.callMainStaticMethod(mainKlassMethod);
+        }
+    }
+
+}
--- a/src/main/java/haidnor/jvm/classloader/BootstrapClassLoader.java
+++ b/src/main/java/haidnor/jvm/classloader/BootstrapClassLoader.java
@@ -0,0 +1,5 @@
+package haidnor.jvm.classloader;
+
+public class BootstrapClassLoader {
+
+}
--- a/src/main/java/haidnor/jvm/classloader/ClassLoader.java
+++ b/src/main/java/haidnor/jvm/classloader/ClassLoader.java
@@ -0,0 +1,82 @@
+package haidnor.jvm.classloader;
+
+import haidnor.jvm.rtda.heap.Klass;
+import haidnor.jvm.rtda.metaspace.Metaspace;
+import org.apache.bcel.classfile.ClassParser;
+import org.apache.bcel.classfile.JavaClass;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.net.URL;
+import java.util.Properties;
+
+public class ClassLoader {
+
+    public final String name;
+
+    public final static String rtJarPath;
+
+    static {
+        URL resource = ClassLoader.class.getResource("/");
+        String path = resource.getPath();
+        FileInputStream fis;
+        try {
+            fis = new FileInputStream(path + "/haidnorJVM.properties");
+        } catch (FileNotFoundException e) {
+            throw new RuntimeException(e);
+        }
+        Properties properties = new Properties();
+        try {
+            properties.load(fis);
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+        rtJarPath = properties.getProperty("rt.jar");
+    }
+
+    public ClassLoader(String name) {
+        this.name = name;
+    }
+
+    /**
+     * @param classPath 类路径,例如 haidnor/jvm/classloader/ClassLoader
+     */
+    public Klass loadClass(String classPath) throws IOException {
+        ClassParser classParser;
+        if (classPath.startsWith("java/")) {
+            String rtJarPath = getRtJarPath();
+
+            if (!new File(rtJarPath).exists()) {
+                throw new IllegalStateException("rt.jar not found");
+            }
+            classParser = new ClassParser(rtJarPath, classPath + ".class");
+        } else {
+            URL resource = this.getClass().getResource("/");
+            String fileName = resource.getPath() + classPath + ".class";
+            classParser = new ClassParser(fileName);
+        }
+
+        JavaClass javaClass = classParser.parse();
+        Klass klass = new Klass(this, javaClass);
+        Metaspace.registerJavaClass(klass);
+        return klass;
+    }
+
+    public Klass loadClassWithAbsolutePath(String absolutePath) throws IOException {
+        ClassParser classParser = new ClassParser(absolutePath);
+        JavaClass javaClass = classParser.parse();
+        Klass klass = new Klass(this, javaClass);
+        Metaspace.registerJavaClass(klass);
+        return klass;
+    }
+
+    private String getRtJarPath() {
+        // String javaHome = System.getenv("JAVA_HOME");
+        //  Path rtJarPath = Paths.get(javaHome, "jre", "lib", "rt.jar");
+        return rtJarPath;
+    }
+
+
+}
--- a/src/main/java/haidnor/jvm/core/Interpreter.java
+++ b/src/main/java/haidnor/jvm/core/Interpreter.java
@@ -0,0 +1,49 @@
+package haidnor.jvm.core;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.instruction.InstructionFactory;
+import haidnor.jvm.instruction.control.RETURN;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+import lombok.SneakyThrows;
+import lombok.extern.slf4j.Slf4j;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * 字节码执行解释器
+ */
+@Slf4j
+public class Interpreter {
+
+    @SneakyThrows
+    public static void executeFrame(Frame frame) {
+        log.debug("------------------------------ Frame START {}", frame.hashCode());
+        Map<Integer, Instruction> instructionMap = new HashMap<>();
+
+        // 解析方法中的字节码指令
+        log.debug(">>>>>>>>>>>>>>>> PARSE INST START");
+        CodeStream codeStream = frame.getCodeStream();
+        while (codeStream.available() > 0) {
+            Instruction instruction = InstructionFactory.creatInstruction(codeStream);
+            log.debug("{}", instruction);
+            instructionMap.put(instruction.index(), instruction);
+        }
+        log.debug(">>>>>>>>>>>>>>>> PARSE INST END");
+
+        // 执行方法中的字节码指令
+        // int i, 相当于程序计数器, 记录当前执行到的字节码指令的”行号“
+        for (int i = 0; i < frame.getCodeLength(); ) {
+            Instruction instruction = instructionMap.get(i);
+            log.debug("{}", instruction);
+            instruction.execute(frame);
+            if (instruction instanceof RETURN) {
+                break;
+            }
+            i += instruction.offSet();
+        }
+        log.debug("------------------------------ Frame End {}", frame.hashCode());
+    }
+
+}
--- a/src/main/java/haidnor/jvm/core/JavaExecutionEngine.java
+++ b/src/main/java/haidnor/jvm/core/JavaExecutionEngine.java
@@ -0,0 +1,57 @@
+package haidnor.jvm.core;
+
+
+import haidnor.jvm.rtda.heap.KlassMethod;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.JvmThread;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.JvmThreadHolder;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.bcel.classfile.LocalVariable;
+import org.apache.bcel.classfile.LocalVariableTable;
+import org.apache.bcel.classfile.Method;
+import org.apache.bcel.classfile.Utility;
+
+@Slf4j
+public class JavaExecutionEngine {
+
+    public static void callMainStaticMethod(KlassMethod klassMethod) {
+        JvmThread jvmThread = JvmThreadHolder.get();
+        // 每个栈帧中包含一个指向运行时常量池中该栈帧所属的方法的引用。包含这个引用的目的就是为了支持当前方法实现动态链接
+        // 有了这个引用，执行引擎就可以找到指定的方法，加载字节码指令
+        Frame frame = new Frame(jvmThread, klassMethod);
+        jvmThread.push(frame);
+        Interpreter.executeFrame(frame);
+    }
+
+    public static void callMethod(Frame lastFrame, KlassMethod klassMethod) {
+        JvmThread jvmThread = JvmThreadHolder.get();
+        Frame newFrame = new Frame(jvmThread, klassMethod);
+
+        Method method = klassMethod.javaMethod;
+        String signature = method.getSignature();
+        String[] argumentTypes = Utility.methodSignatureArgumentTypes(signature);
+
+        int argumentSlotSize = argumentTypes.length;
+        if (!method.isStatic()) {
+            argumentSlotSize++;
+        }
+
+        // 静态方法调用传参
+        // 将上一个栈帧操作数栈中数据弹出,存入下一个栈帧的局部变量表中
+        LocalVariableTable localVariableTable = method.getLocalVariableTable();
+        if (localVariableTable != null) {
+            for (int i = argumentSlotSize - 1; i >= 0; i--) {
+                LocalVariable[] localVariableArr = localVariableTable.getLocalVariableTable();
+                LocalVariable localVariable = localVariableArr[i];
+                int slotIndex = localVariable.getIndex();
+                StackValue stackValue = lastFrame.pop();
+                newFrame.slotSet(slotIndex, stackValue);
+            }
+        }
+        jvmThread.push(newFrame);
+        Interpreter.executeFrame(newFrame);
+    }
+
+
+}
--- a/src/main/java/haidnor/jvm/instruction/Instruction.java
+++ b/src/main/java/haidnor/jvm/instruction/Instruction.java
@@ -0,0 +1,40 @@
+package haidnor.jvm.instruction;
+
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public abstract class Instruction {
+    /**
+     * 指令坐在 code 数组中的索引下标
+     */
+    private final int index;
+
+    /**
+     * 执行下一个执行的偏移量
+     */
+    private int offSet = 1;
+
+    public Instruction(CodeStream codeStream) {
+        this.index = codeStream.index();
+    }
+
+    public abstract void execute(Frame frame);
+
+    public int index() {
+        return index;
+    }
+
+    public final int offSet() {
+        return this.offSet;
+    }
+
+    public void setOffSet(int offSet) {
+        this.offSet = offSet;
+    }
+
+    @Override
+    public String toString() {
+        return index + " " + this.getClass().getSimpleName();
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/InstructionFactory.java
+++ b/src/main/java/haidnor/jvm/instruction/InstructionFactory.java
@@ -0,0 +1,631 @@
+package haidnor.jvm.instruction;
+
+import haidnor.jvm.instruction.comparisons.*;
+import haidnor.jvm.instruction.constants.*;
+import haidnor.jvm.instruction.control.*;
+import haidnor.jvm.instruction.conversions.*;
+import haidnor.jvm.instruction.extended.GOTO;
+import haidnor.jvm.instruction.extended.GOTO_W;
+import haidnor.jvm.instruction.extended.IFNONNULL;
+import haidnor.jvm.instruction.extended.IFNULL;
+import haidnor.jvm.instruction.loads.*;
+import haidnor.jvm.instruction.math.*;
+import haidnor.jvm.instruction.references.*;
+import haidnor.jvm.instruction.stack.*;
+import haidnor.jvm.instruction.stores.*;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+public abstract class InstructionFactory {
+
+    public static Instruction creatInstruction(CodeStream codeStream) {
+        int opcode = codeStream.readJavaVmOpcode();
+        switch (opcode) {
+            case Const.NOP -> {
+                return new NOP(codeStream);
+            }
+            case Const.ACONST_NULL -> {
+                return new ACONST_NULL(codeStream);
+            }
+            case Const.ICONST_M1 -> {
+                return new ICONST_M1(codeStream);
+            }
+            case Const.ICONST_0 -> {
+                return new ICONST_0(codeStream);
+            }
+            case Const.ICONST_1 -> {
+                return new ICONST_1(codeStream);
+            }
+            case Const.ICONST_2 -> {
+                return new ICONST_2(codeStream);
+            }
+            case Const.ICONST_3 -> {
+                return new ICONST_3(codeStream);
+            }
+            case Const.ICONST_4 -> {
+                return new ICONST_4(codeStream);
+            }
+            case Const.ICONST_5 -> {
+                return new ICONST_5(codeStream);
+            }
+            case Const.LCONST_0 -> {
+                return new LCONST_0(codeStream);
+            }
+            case Const.LCONST_1 -> {
+                return new LCONST_1(codeStream);
+            }
+            case Const.FCONST_1 -> {
+                return new FCONST_1(codeStream);
+            }
+            case Const.FCONST_2 -> {
+                return new FCONST_2(codeStream);
+            }
+            case Const.DCONST_0 -> {
+                return new DCONST_0(codeStream);
+            }
+            case Const.DCONST_1 -> {
+                return new DCONST_1(codeStream);
+            }
+            case Const.BIPUSH -> {
+                return new BIPUSH(codeStream);
+            }
+            case Const.SIPUSH -> {
+                return new SIPUSH(codeStream);
+            }
+            case Const.LDC -> {
+                return new LDC(codeStream);
+            }
+            case Const.LDC_W -> {
+                return new LDC_W(codeStream);
+            }
+            case Const.LDC2_W -> {
+                return new LDC2W(codeStream);
+            }
+            case Const.ILOAD -> {
+                return new ILOAD(codeStream);
+            }
+            case Const.LLOAD -> {
+                return new LLOAD(codeStream);
+            }
+            case Const.FLOAD -> {
+                return new FLOAD(codeStream);
+            }
+            case Const.DLOAD -> {
+                return new DLOAD(codeStream);
+            }
+            case Const.ALOAD -> {
+                return new ALOAD(codeStream);
+            }
+            case Const.ILOAD_0 -> {
+                return new ILOAD_0(codeStream);
+            }
+            case Const.ILOAD_1 -> {
+                return new ILOAD_1(codeStream);
+            }
+            case Const.ILOAD_2 -> {
+                return new ILOAD_2(codeStream);
+            }
+            case Const.ILOAD_3 -> {
+                return new ILOAD_3(codeStream);
+            }
+            case Const.LLOAD_0 -> {
+                return new LLOAD_0(codeStream);
+            }
+            case Const.LLOAD_1 -> {
+                return new LLOAD_1(codeStream);
+            }
+            case Const.LLOAD_2 -> {
+                return new LLOAD_2(codeStream);
+            }
+            case Const.LLOAD_3 -> {
+                return new LLOAD_3(codeStream);
+            }
+            case Const.FLOAD_0 -> {
+                return new FLOAD_0(codeStream);
+            }
+            case Const.FLOAD_1 -> {
+                return new FLOAD_1(codeStream);
+            }
+            case Const.FLOAD_2 -> {
+                return new FLOAD_2(codeStream);
+            }
+            case Const.FLOAD_3 -> {
+                return new FLOAD_3(codeStream);
+            }
+            case Const.DLOAD_0 -> {
+                return new DLOAD_0(codeStream);
+            }
+            case Const.DLOAD_1 -> {
+                return new DLOAD_1(codeStream);
+            }
+            case Const.DLOAD_2 -> {
+                return new DLOAD_2(codeStream);
+            }
+            case Const.DLOAD_3 -> {
+                return new DLOAD_3(codeStream);
+            }
+            case Const.ALOAD_0 -> {
+                return new ALOAD_0(codeStream);
+            }
+            case Const.ALOAD_1 -> {
+                return new ALOAD_1(codeStream);
+            }
+            case Const.ALOAD_2 -> {
+                return new ALOAD_2(codeStream);
+            }
+            case Const.ALOAD_3 -> {
+                return new ALOAD_3(codeStream);
+            }
+            case Const.IALOAD -> {
+                return new IALOAD(codeStream);
+            }
+            case Const.LALOAD -> {
+                return new LALOAD(codeStream);
+            }
+            case Const.FALOAD -> {
+                return new FALOAD(codeStream);
+            }
+            case Const.DALOAD -> {
+                return new DALOAD(codeStream);
+            }
+            case Const.AALOAD -> {
+                return new AALOAD(codeStream);
+            }
+            case Const.BALOAD -> {
+                return new BALOAD(codeStream);
+            }
+            case Const.CALOAD -> {
+                return new CALOAD(codeStream);
+            }
+            case Const.SALOAD -> {
+                return new SALOAD(codeStream);
+            }
+            case Const.ISTORE -> {
+                return new ISTORE(codeStream);
+            }
+            case Const.LSTORE -> {
+                return new LSTORE(codeStream);
+            }
+            case Const.FSTORE -> {
+                return new FSTORE(codeStream);
+            }
+            case Const.DSTORE -> {
+                return new DSTORE(codeStream);
+            }
+            case Const.ASTORE -> {
+                return new ASTORE(codeStream);
+            }
+            case Const.ISTORE_0 -> {
+                return new ISTORE_0(codeStream);
+            }
+            case Const.ISTORE_1 -> {
+                return new ISTORE_1(codeStream);
+            }
+            case Const.ISTORE_2 -> {
+                return new ISTORE_2(codeStream);
+            }
+            case Const.ISTORE_3 -> {
+                return new ISTORE_3(codeStream);
+            }
+            case Const.LSTORE_0 -> {
+                return new LSTORE_0(codeStream);
+            }
+            case Const.LSTORE_1 -> {
+                return new LSTORE_1(codeStream);
+            }
+            case Const.LSTORE_2 -> {
+                return new LSTORE_2(codeStream);
+            }
+            case Const.LSTORE_3 -> {
+                return new LSTORE_3(codeStream);
+            }
+            case Const.FSTORE_0 -> {
+                return new FSTORE_0(codeStream);
+            }
+            case Const.FSTORE_1 -> {
+                return new FSTORE_1(codeStream);
+            }
+            case Const.FSTORE_2 -> {
+                return new FSTORE_2(codeStream);
+            }
+            case Const.FSTORE_3 -> {
+                return new FSTORE_3(codeStream);
+            }
+            case Const.DSTORE_0 -> {
+                return new DSTORE_0(codeStream);
+            }
+            case Const.DSTORE_1 -> {
+                return new DSTORE_1(codeStream);
+            }
+            case Const.DSTORE_2 -> {
+                return new DSTORE_2(codeStream);
+            }
+            case Const.DSTORE_3 -> {
+                return new DSTORE_3(codeStream);
+            }
+            case Const.ASTORE_0 -> {
+                return new ASTORE_0(codeStream);
+            }
+            case Const.ASTORE_1 -> {
+                return new ASTORE_1(codeStream);
+            }
+            case Const.ASTORE_2 -> {
+                return new ASTORE_2(codeStream);
+            }
+            case Const.ASTORE_3 -> {
+                return new ASTORE_3(codeStream);
+            }
+            case Const.IASTORE -> {
+                return new IASTORE(codeStream);
+            }
+            case Const.LASTORE -> {
+                return new LASTORE(codeStream);
+            }
+            case Const.FASTORE -> {
+                return new FASTORE(codeStream);
+            }
+            case Const.DASTORE -> {
+                return new DASTORE(codeStream);
+            }
+            case Const.AASTORE -> {
+                return new AASTORE(codeStream);
+            }
+            case Const.BASTORE -> {
+                return new BASTORE(codeStream);
+            }
+            case Const.CASTORE -> {
+                return new CASTORE(codeStream);
+            }
+            case Const.SASTORE -> {
+                return new SASTORE(codeStream);
+            }
+            case Const.POP -> {
+                return new POP(codeStream);
+            }
+            case Const.POP2 -> {
+                return new POP2(codeStream);
+            }
+            case Const.DUP -> {
+                return new DUP(codeStream);
+            }
+            case Const.DUP_X1 -> {
+                return new DUP_X1(codeStream);
+            }
+            case Const.DUP_X2 -> {
+                return new DUP_X2(codeStream);
+            }
+            case Const.DUP2 -> {
+                return new DUP2(codeStream);
+            }
+            case Const.DUP2_X1 -> {
+                throw new Error("Not support JavaVM opcode DUP2_X1");
+            }
+            case Const.DUP2_X2 -> {
+                throw new Error("Not support JavaVM opcode DUP2_X2");
+            }
+            case Const.SWAP -> {
+                return new SWAP(codeStream);
+            }
+            case Const.IADD -> {
+                return new IADD(codeStream);
+            }
+            case Const.LADD -> {
+                return new LADD(codeStream);
+            }
+            case Const.FADD -> {
+                return new FADD(codeStream);
+            }
+            case Const.DADD -> {
+                return new DADD(codeStream);
+            }
+            case Const.ISUB -> {
+                return new ISUB(codeStream);
+            }
+            case Const.LSUB -> {
+                return new LSUB(codeStream);
+            }
+            case Const.FSUB -> {
+                return new FSUB(codeStream);
+            }
+            case Const.DSUB -> {
+                return new DSUB(codeStream);
+            }
+            case Const.IMUL -> {
+                return new IMUL(codeStream);
+            }
+            case Const.LMUL -> {
+                return new LMUL(codeStream);
+            }
+            case Const.FMUL -> {
+                return new FMUL(codeStream);
+            }
+            case Const.DMUL -> {
+                return new DMUL(codeStream);
+            }
+            case Const.IDIV -> {
+                return new IDIV(codeStream);
+            }
+            case Const.LDIV -> {
+                return new LDIV(codeStream);
+            }
+            case Const.FDIV -> {
+                return new FDIV(codeStream);
+            }
+            case Const.DDIV -> {
+                return new DDIV(codeStream);
+            }
+            case Const.IREM -> {
+                return new IREM(codeStream);
+            }
+            case Const.LREM -> {
+                return new LREM(codeStream);
+            }
+            case Const.FREM -> {
+                return new FREM(codeStream);
+            }
+            case Const.DREM -> {
+                return new DREM(codeStream);
+            }
+            case Const.INEG -> {
+                return new INEG(codeStream);
+            }
+            case Const.LNEG -> {
+                return new LNEG(codeStream);
+            }
+            case Const.FNEG -> {
+                return new FNEG(codeStream);
+            }
+            case Const.DNEG -> {
+                return new DNEG(codeStream);
+            }
+            case Const.ISHL -> {
+                return new ISHL(codeStream);
+            }
+            case Const.LSHL -> {
+                return new LSHL(codeStream);
+            }
+            case Const.ISHR -> {
+                return new ISHR(codeStream);
+            }
+            case Const.LSHR -> {
+                return new LSHR(codeStream);
+            }
+            case Const.IUSHR -> {
+                return new IUSHR(codeStream);
+            }
+            case Const.LUSHR -> {
+                return new LUSHR(codeStream);
+            }
+            case Const.IAND -> {
+                return new IAND(codeStream);
+            }
+            case Const.LAND -> {
+                return new LAND(codeStream);
+            }
+            case Const.IOR -> {
+                return new IOR(codeStream);
+            }
+            case Const.LOR -> {
+                return new LOR(codeStream);
+            }
+            case Const.IXOR -> {
+                return new IXOR(codeStream);
+            }
+            case Const.LXOR -> {
+                return new LXOR(codeStream);
+            }
+            case Const.IINC -> {
+                return new IINC(codeStream);
+            }
+            case Const.I2L -> {
+                return new I2L(codeStream);
+            }
+            case Const.I2F -> {
+                return new I2F(codeStream);
+            }
+            case Const.I2D -> {
+                return new I2D(codeStream);
+            }
+            case Const.L2I -> {
+                return new L2I(codeStream);
+            }
+            case Const.L2F -> {
+                return new L2F(codeStream);
+            }
+            case Const.L2D -> {
+                return new L2D(codeStream);
+            }
+            case Const.F2I -> {
+                return new F2I(codeStream);
+            }
+            case Const.F2L -> {
+                return new F2L(codeStream);
+            }
+            case Const.F2D -> {
+                return new F2D(codeStream);
+            }
+            case Const.D2I -> {
+                return new D2I(codeStream);
+            }
+            case Const.D2L -> {
+                return new D2L(codeStream);
+            }
+            case Const.D2F -> {
+                return new D2F(codeStream);
+            }
+            case Const.I2B -> {
+                return new I2B(codeStream);
+            }
+            case Const.I2C -> {
+                return new I2C(codeStream);
+            }
+            case Const.I2S -> {
+                return new I2S(codeStream);
+            }
+            case Const.LCMP -> {
+                return new LCMP(codeStream);
+            }
+            case Const.FCMPL -> {
+                return new FCMPL(codeStream);
+            }
+            case Const.FCMPG -> {
+                return new FCMPG(codeStream);
+            }
+            case Const.DCMPL -> {
+                return new DCMPL(codeStream);
+            }
+            case Const.DCMPG -> {
+                return new DCMPG(codeStream);
+            }
+            case Const.IFEQ -> {
+                return new IFEQ(codeStream);
+            }
+            case Const.IFNE -> {
+                return new IFNE(codeStream);
+            }
+            case Const.IFLT -> {
+                return new IFLT(codeStream);
+            }
+            case Const.IFGE -> {
+                return new IFGE(codeStream);
+            }
+            case Const.IFGT -> {
+                return new IFGT(codeStream);
+            }
+            case Const.IFLE -> {
+                return new IFLE(codeStream);
+            }
+            case Const.IF_ICMPEQ -> {
+                return new IF_ICMPEQ(codeStream);
+            }
+            case Const.IF_ICMPNE -> {
+                return new IF_ICMPNE(codeStream);
+            }
+            case Const.IF_ICMPLT -> {
+                return new IF_ICMPLT(codeStream);
+            }
+            case Const.IF_ICMPGE -> {
+                return new IF_ICMPGE(codeStream);
+            }
+            case Const.IF_ICMPGT -> {
+                return new IF_ICMPGT(codeStream);
+            }
+            case Const.IF_ICMPLE -> {
+                return new IF_ICMPLE(codeStream);
+            }
+            case Const.IF_ACMPEQ -> {
+                return new IF_ACMPEQ(codeStream);
+            }
+            case Const.IF_ACMPNE -> {
+                return new IF_ACMPNE(codeStream);
+            }
+            case Const.GOTO -> {
+                return new GOTO(codeStream);
+            }
+            case Const.JSR -> {
+                return new JSR(codeStream);
+            }
+            case Const.RET -> {
+                return new RET(codeStream);
+            }
+            case Const.TABLESWITCH -> {
+                throw new Error("Not support JavaVM opcode TABLESWITCH");
+            }
+            case Const.LOOKUPSWITCH -> {
+                throw new Error("Not support JavaVM opcode LOOKUPSWITCH");
+            }
+            case Const.IRETURN -> {
+                return new IRETURN(codeStream);
+            }
+            case Const.LRETURN -> {
+                return new LRETURN(codeStream);
+            }
+            case Const.FRETURN -> {
+                return new FRETURN(codeStream);
+            }
+            case Const.DRETURN -> {
+                return new DRETURN(codeStream);
+            }
+            case Const.ARETURN -> {
+                throw new Error("Not support JavaVM opcode ARETURN");
+            }
+            case Const.RETURN -> {
+                return new RETURN(codeStream);
+            }
+            case Const.GETSTATIC -> {
+                return new GETSTATIC(codeStream);
+            }
+            case Const.PUTSTATIC -> {
+                throw new Error("Not support JavaVM opcode PUTSTATIC");
+            }
+            case Const.GETFIELD -> {
+                return new GETFIELD(codeStream);
+            }
+            case Const.PUTFIELD -> {
+                return new PUTFIELD(codeStream);
+            }
+            case Const.INVOKEVIRTUAL -> {
+                return new INVOKEVIRTUAL(codeStream);
+            }
+            case Const.INVOKESPECIAL -> {
+                return new INVOKESPECIAL(codeStream);
+            }
+            case Const.INVOKESTATIC -> {
+                return new INVOKESTATIC(codeStream);
+            }
+            case Const.INVOKEINTERFACE -> {
+                throw new Error("Not support JavaVM opcode INVOKEINTERFACE");
+            }
+            case Const.INVOKEDYNAMIC -> {
+                throw new Error("Not support JavaVM opcode INVOKEDYNAMIC");
+            }
+            case Const.NEW -> {
+                return new NEW(codeStream);
+            }
+            case Const.NEWARRAY -> {
+                return new NEWARRAY(codeStream);
+            }
+            case Const.ANEWARRAY -> {
+                return new ANEWARRAY(codeStream);
+            }
+            case Const.ARRAYLENGTH -> {
+                return new ARRAYLENGTH(codeStream);
+            }
+            case Const.ATHROW -> {
+                throw new Error("Not support JavaVM opcode ATHROW");
+            }
+            case Const.CHECKCAST -> {
+                return new CHECKCAST(codeStream);
+            }
+            case Const.INSTANCEOF -> {
+                throw new Error("Not support JavaVM opcode INSTANCEOF");
+            }
+            case Const.MONITORENTER -> {
+                throw new Error("Not support JavaVM opcode MONITORENTER");
+            }
+            case Const.MONITOREXIT -> {
+                throw new Error("Not support JavaVM opcode MONITOREXIT");
+            }
+            case Const.WIDE -> {
+                throw new Error("Not support JavaVM opcode WIDE");
+            }
+            case Const.MULTIANEWARRAY -> {
+                throw new Error("Not support JavaVM opcode MULTIANEWARRAY");
+            }
+            case Const.IFNULL -> {
+                return new IFNULL(codeStream);
+            }
+            case Const.IFNONNULL -> {
+                return new IFNONNULL(codeStream);
+            }
+            case Const.GOTO_W -> {
+                return new GOTO_W(codeStream);
+            }
+            case Const.JSR_W -> {
+                return new JSR_W(codeStream);
+            }
+            default -> throw new Error("Unknown JavaVM opcode " + opcode);
+        }
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/DCMPG.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/DCMPG.java
@@ -0,0 +1,28 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class DCMPG extends Instruction {
+
+    public DCMPG(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        double v2 = frame.popDouble();
+        double v1 = frame.popDouble();
+        if (v1 == v2) {
+            frame.pushInt(0);
+            return;
+        }
+        if (v1 < v2) {
+            frame.pushInt(-1);
+            return;
+        }
+        frame.pushInt(1);
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/DCMPL.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/DCMPL.java
@@ -0,0 +1,28 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class DCMPL extends Instruction {
+
+    public DCMPL(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        Double v2 = frame.popDouble();
+        Double v1 = frame.popDouble();
+        if (v1.equals(v2)) {
+            frame.pushInt(0);
+            return;
+        }
+        if (v1 < v2) {
+            frame.pushInt(-1);
+            return;
+        }
+        frame.pushInt(1);
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/FCMPG.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/FCMPG.java
@@ -0,0 +1,28 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class FCMPG extends Instruction {
+
+    public FCMPG(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        float v2 = frame.popFloat();
+        float v1 = frame.popFloat();
+        if (v1 == v2) {
+            frame.pushInt(0);
+            return;
+        }
+        if (v1 < v2) {
+            frame.pushInt(-1);
+            return;
+        }
+        frame.pushInt(1);
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/FCMPL.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/FCMPL.java
@@ -0,0 +1,28 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class FCMPL extends Instruction {
+
+    public FCMPL(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        float v2 = frame.popFloat();
+        float v1 = frame.popFloat();
+        if (v1 == v2) {
+            frame.pushInt(0);
+            return;
+        }
+        if (v1 < v2) {
+            frame.pushInt(-1);
+            return;
+        }
+        frame.pushInt(1);
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/IFEQ.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/IFEQ.java
@@ -0,0 +1,34 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+
+public class IFEQ extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public IFEQ(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        StackValue v1 = frame.pop();
+        if ((int) v1.getValue() == 0) {
+            super.setOffSet(offSet);
+        } else {
+            super.setOffSet(3);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " "  + offSet;
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/IFGE.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/IFGE.java
@@ -0,0 +1,34 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+
+public class IFGE extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public IFGE(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        StackValue v1 = frame.pop();
+        if ((int) v1.getValue() >= 0) {
+            super.setOffSet(offSet);
+        } else {
+            super.setOffSet(3);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " "  + offSet;
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/IFGT.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/IFGT.java
@@ -0,0 +1,34 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+
+public class IFGT extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public IFGT(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        StackValue v1 = frame.pop();
+        if ((int) v1.getValue() > 0) {
+            super.setOffSet(offSet);
+        } else {
+            super.setOffSet(3);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " "  + offSet;
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/IFLE.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/IFLE.java
@@ -0,0 +1,34 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+
+public class IFLE extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public IFLE(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        StackValue v1 = frame.pop();
+        if ((int) v1.getValue() <= 0) {
+            super.setOffSet(offSet);
+        } else {
+            super.setOffSet(3);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " "  + offSet;
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/IFLT.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/IFLT.java
@@ -0,0 +1,34 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+
+public class IFLT extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public IFLT(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        StackValue v1 = frame.pop();
+        if ((int) v1.getValue() < 0) {
+            super.setOffSet(offSet);
+        } else {
+            super.setOffSet(3);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " "  + offSet;
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/IFNE.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/IFNE.java
@@ -0,0 +1,34 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+
+public class IFNE extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public IFNE(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        StackValue v1 = frame.pop();
+        if ((int) v1.getValue() != 0) {
+            super.setOffSet(offSet);
+        } else {
+            super.setOffSet(3);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " "  + offSet;
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/IF_ACMPEQ.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/IF_ACMPEQ.java
@@ -0,0 +1,34 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class IF_ACMPEQ extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public IF_ACMPEQ(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        Object val2 = frame.popRef();
+        Object val1 = frame.popRef();
+        if (val1 == val2) {
+            super.setOffSet(offSet);
+        } else {
+            super.setOffSet(3);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " " + offSet;
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/IF_ACMPNE.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/IF_ACMPNE.java
@@ -0,0 +1,34 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class IF_ACMPNE extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public IF_ACMPNE(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        Object val2 = frame.popRef();
+        Object val1 = frame.popRef();
+        if (val1 != val2) {
+            super.setOffSet(offSet);
+        } else {
+            super.setOffSet(3);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " " + offSet;
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/IF_ICMPEQ.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/IF_ICMPEQ.java
@@ -0,0 +1,41 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.if_icmp_cond"> Opcode
+ * definitions in The Java Virtual Machine Specification</a>
+ */
+public class IF_ICMPEQ extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public IF_ICMPEQ(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        StackValue v1 = frame.pop();
+        StackValue v2 = frame.pop();
+
+        if ((int) v1.getValue() == (int) v2.getValue()) {
+            super.setOffSet(offSet);
+        } else {
+            super.setOffSet(3);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " "  + offSet;
+    }
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/IF_ICMPGE.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/IF_ICMPGE.java
@@ -0,0 +1,42 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.if_icmp_cond"> Opcode
+ * definitions in The Java Virtual Machine Specification</a>
+ */
+public class IF_ICMPGE extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public IF_ICMPGE(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        StackValue v2 = frame.pop();
+        StackValue v1 = frame.pop();
+
+        if ((int) v1.getValue() >= (int) v2.getValue()) {
+            super.setOffSet(offSet);
+        } else {
+            super.setOffSet(3);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " "  + offSet;
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/IF_ICMPGT.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/IF_ICMPGT.java
@@ -0,0 +1,42 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.if_icmp_cond"> Opcode
+ * definitions in The Java Virtual Machine Specification</a>
+ */
+public class IF_ICMPGT extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public IF_ICMPGT(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        StackValue v2 = frame.pop();
+        StackValue v1 = frame.pop();
+
+        if ((int) v1.getValue() > (int) v2.getValue()) {
+            super.setOffSet(offSet);
+        } else {
+            super.setOffSet(3);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " "  + offSet;
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/IF_ICMPLE.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/IF_ICMPLE.java
@@ -0,0 +1,42 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.if_icmp_cond"> Opcode
+ * definitions in The Java Virtual Machine Specification</a>
+ */
+public class IF_ICMPLE extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public IF_ICMPLE(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        StackValue v2 = frame.pop();
+        StackValue v1 = frame.pop();
+
+        if ((int) v1.getValue() <= (int) v2.getValue()) {
+            super.setOffSet(offSet);
+        } else {
+            super.setOffSet(3);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " "  + offSet;
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/IF_ICMPLT.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/IF_ICMPLT.java
@@ -0,0 +1,42 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.if_icmp_cond"> Opcode
+ * definitions in The Java Virtual Machine Specification</a>
+ */
+public class IF_ICMPLT extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public IF_ICMPLT(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        StackValue v2 = frame.pop();
+        StackValue v1 = frame.pop();
+
+        if ((int) v1.getValue() < (int) v2.getValue()) {
+            super.setOffSet(offSet);
+        } else {
+            super.setOffSet(3);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " "  + offSet;
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/IF_ICMPNE.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/IF_ICMPNE.java
@@ -0,0 +1,42 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.if_icmp_cond"> Opcode
+ * definitions in The Java Virtual Machine Specification</a>
+ */
+public class IF_ICMPNE extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public IF_ICMPNE(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        StackValue v1 = frame.pop();
+        StackValue v2 = frame.pop();
+
+        if ((int) v1.getValue() != (int) v2.getValue()) {
+            super.setOffSet(offSet);
+        } else {
+            super.setOffSet(3);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " "  + offSet;
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/comparisons/LCMP.java
+++ b/src/main/java/haidnor/jvm/instruction/comparisons/LCMP.java
@@ -0,0 +1,28 @@
+package haidnor.jvm.instruction.comparisons;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class LCMP extends Instruction {
+
+    public LCMP(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        Long v2 = frame.popLong();
+        Long v1 = frame.popLong();
+        if (v1.equals(v2)) {
+            frame.pushInt(0);
+            return;
+        }
+        if (v1 < v2) {
+            frame.pushInt(-1);
+            return;
+        }
+        frame.pushInt(1);
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/ACONST_NULL.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/ACONST_NULL.java
@@ -0,0 +1,20 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+public class ACONST_NULL extends Instruction {
+
+    public ACONST_NULL(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        frame.push(new StackValue(Const.T_OBJECT, null));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/BIPUSH.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/BIPUSH.java
@@ -0,0 +1,29 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.bipush"> Opcode definitions in
+ * The Java Virtual Machine Specification</a>
+ */
+public class BIPUSH extends Instruction {
+
+    private final int value;
+
+    public BIPUSH(CodeStream codeStream) {
+        super(codeStream);
+        this.value = codeStream.readByte(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        frame.push(new StackValue(Const.T_INT, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/DCONST_0.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/DCONST_0.java
@@ -0,0 +1,26 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.dconst_d"> Opcode definitions
+ *      in The Java Virtual Machine Specification</a>
+ */
+public class DCONST_0 extends Instruction {
+
+    public DCONST_0(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        frame.push(new StackValue(Const.T_DOUBLE, 0.0D));
+    }
+    
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/DCONST_1.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/DCONST_1.java
@@ -0,0 +1,26 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.dconst_d"> Opcode definitions
+ *      in The Java Virtual Machine Specification</a>
+ */
+public class DCONST_1 extends Instruction {
+
+    public DCONST_1(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        frame.push(new StackValue(Const.T_DOUBLE, 1.0D));
+    }
+    
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/FCONST_1.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/FCONST_1.java
@@ -0,0 +1,26 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.fconst_f"> Opcode definitions
+ *      in The Java Virtual Machine Specification</a>
+ */
+public class FCONST_1 extends Instruction {
+
+    public FCONST_1(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        frame.push(new StackValue(Const.T_FLOAT, 1.0f));
+    }
+    
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/FCONST_2.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/FCONST_2.java
@@ -0,0 +1,26 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.fconst_f"> Opcode definitions
+ *      in The Java Virtual Machine Specification</a>
+ */
+public class FCONST_2 extends Instruction {
+
+    public FCONST_2(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        frame.push(new StackValue(Const.T_FLOAT, 2.0f));
+    }
+    
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/ICONST_0.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/ICONST_0.java
@@ -0,0 +1,23 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * https://docs.oracle.com/javase/specs/jvms/se19/html/jvms-6.html#jvms-6.5.iconst_i
+ */
+public class ICONST_0 extends Instruction {
+
+    public ICONST_0(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        frame.push(new StackValue(Const.T_INT, 0));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/ICONST_1.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/ICONST_1.java
@@ -0,0 +1,23 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * https://docs.oracle.com/javase/specs/jvms/se19/html/jvms-6.html#jvms-6.5.iconst_i
+ */
+public class ICONST_1 extends Instruction {
+
+    public ICONST_1(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        frame.push(new StackValue(Const.T_INT, 1));
+    }
+    
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/ICONST_2.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/ICONST_2.java
@@ -0,0 +1,23 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * https://docs.oracle.com/javase/specs/jvms/se19/html/jvms-6.html#jvms-6.5.iconst_i
+ */
+public class ICONST_2 extends Instruction {
+
+    public ICONST_2(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        frame.push(new StackValue(Const.T_INT, 2));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/ICONST_3.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/ICONST_3.java
@@ -0,0 +1,23 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * https://docs.oracle.com/javase/specs/jvms/se19/html/jvms-6.html#jvms-6.5.iconst_i
+ */
+public class ICONST_3 extends Instruction {
+
+    public ICONST_3(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        frame.push(new StackValue(Const.T_INT, 3));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/ICONST_4.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/ICONST_4.java
@@ -0,0 +1,23 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * https://docs.oracle.com/javase/specs/jvms/se19/html/jvms-6.html#jvms-6.5.iconst_i
+ */
+public class ICONST_4 extends Instruction {
+
+    public ICONST_4(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        frame.push(new StackValue(Const.T_INT, 4));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/ICONST_5.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/ICONST_5.java
@@ -0,0 +1,23 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * https://docs.oracle.com/javase/specs/jvms/se19/html/jvms-6.html#jvms-6.5.iconst_i
+ */
+public class ICONST_5 extends Instruction {
+
+    public ICONST_5(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        frame.push(new StackValue(Const.T_INT, 5));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/ICONST_M1.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/ICONST_M1.java
@@ -0,0 +1,23 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * https://docs.oracle.com/javase/specs/jvms/se19/html/jvms-6.html#jvms-6.5.iconst_i
+ */
+public class ICONST_M1 extends Instruction {
+
+    public ICONST_M1(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        frame.push(new StackValue(Const.T_INT, -1));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/LCONST_0.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/LCONST_0.java
@@ -0,0 +1,26 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.lconst_l"> Opcode definitions
+ *      in The Java Virtual Machine Specification</a>
+ */
+public class LCONST_0 extends Instruction {
+
+    public LCONST_0(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        frame.push(new StackValue(Const.T_LONG, 0L));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/LCONST_1.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/LCONST_1.java
@@ -0,0 +1,26 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.lconst_l"> Opcode definitions
+ *      in The Java Virtual Machine Specification</a>
+ */
+public class LCONST_1 extends Instruction {
+
+    public LCONST_1(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        frame.push(new StackValue(Const.T_LONG, 1L));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/LDC.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/LDC.java
@@ -0,0 +1,58 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import lombok.SneakyThrows;
+import org.apache.bcel.Const;
+import org.apache.bcel.classfile.*;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.ldc"> Opcode definitions in The
+ *      Java Virtual Machine Specification</a>
+ */
+public class LDC extends Instruction {
+
+    private final int constantIndex;
+
+    public LDC(CodeStream codeStream) {
+        super(codeStream);
+        this.constantIndex = codeStream.readUnsignedByte(this);
+    }
+
+    @Override
+    @SneakyThrows
+    public void execute(Frame frame) {
+        ConstantPool constantPool = frame.getConstantPool();
+
+        // 从常量池中获取值
+        Constant constant = constantPool.getConstant(constantIndex);
+
+        switch (constant.getTag()) {
+            case Const.CONSTANT_Integer: {
+                ConstantInteger constantInteger = (ConstantInteger) constant;
+                Object value = constantInteger.getConstantValue(constantPool);
+                frame.push(new StackValue(Const.T_INT, value));
+                break;
+            }
+            case Const.CONSTANT_Float: {
+                ConstantFloat constantFloat = (ConstantFloat) constant;
+                Object value = constantFloat.getConstantValue(constantPool);
+                frame.push(new StackValue(Const.T_FLOAT, value));
+                break;
+            }
+            case Const.CONSTANT_String: {
+                ConstantString constString = (ConstantString) constant;
+                Object value = constString.getConstantValue(constantPool);
+                frame.push(new StackValue(Const.T_OBJECT, value));
+                break;
+            }
+            default:
+                throw new Error("not supported LDC type" + constant.getTag());
+        }
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/LDC2W.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/LDC2W.java
@@ -0,0 +1,48 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+import org.apache.bcel.classfile.Constant;
+import org.apache.bcel.classfile.ConstantDouble;
+import org.apache.bcel.classfile.ConstantLong;
+import org.apache.bcel.classfile.ConstantPool;
+
+/**
+ * 将 long 或 double 型常量从常量池中推送至栈顶 (宽索引)
+ */
+public class LDC2W extends Instruction {
+
+    private final byte constantTag;
+
+    private long longValue;
+
+    private double doubleValue;
+
+    public LDC2W(CodeStream codeStream) {
+        super(codeStream);
+        int index = codeStream.readUnsignedShort(this);
+        ConstantPool constantPool = codeStream.getCode().getConstantPool();
+        Constant constant = constantPool.getConstant(index);
+        this.constantTag = constant.getTag();
+        if (constantTag == Const.CONSTANT_Long) {
+            ConstantLong constantLong = (ConstantLong) constant;
+            this.longValue = constantLong.getBytes();
+        } else if (constantTag == Const.CONSTANT_Double) {
+            ConstantDouble constantDouble = (ConstantDouble) constant;
+            this.doubleValue = constantDouble.getBytes();
+        }
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        if (constantTag == Const.CONSTANT_Long) {
+            frame.push(new StackValue(Const.T_LONG, this.longValue));
+        } else if (constantTag == Const.CONSTANT_Double) {
+            frame.push(new StackValue(Const.T_DOUBLE, this.doubleValue));
+        }
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/LDC_W.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/LDC_W.java
@@ -0,0 +1,58 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import lombok.SneakyThrows;
+import org.apache.bcel.Const;
+import org.apache.bcel.classfile.*;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.ldc_w"> Opcode definitions in
+ *      The Java Virtual Machine Specification</a>
+ */
+public class LDC_W extends Instruction {
+
+    private final int constantIndex;
+
+    public LDC_W(CodeStream codeStream) {
+        super(codeStream);
+        this.constantIndex = codeStream.readUnsignedShort(this);
+    }
+
+    @Override
+    @SneakyThrows
+    public void execute(Frame frame) {
+        ConstantPool constantPool = frame.getConstantPool();
+
+        // 从常量池中获取值
+        Constant constant = constantPool.getConstant(constantIndex);
+
+        switch (constant.getTag()) {
+            case Const.CONSTANT_Integer: {
+                ConstantInteger constantInteger = (ConstantInteger) constant;
+                Object value = constantInteger.getConstantValue(constantPool);
+                frame.push(new StackValue(Const.T_INT, value));
+                break;
+            }
+            case Const.CONSTANT_Float: {
+                ConstantFloat constantFloat = (ConstantFloat) constant;
+                Object value = constantFloat.getConstantValue(constantPool);
+                frame.push(new StackValue(Const.T_FLOAT, value));
+                break;
+            }
+            case Const.CONSTANT_String: {
+                ConstantString constString = (ConstantString) constant;
+                Object value = constString.getConstantValue(constantPool);
+                frame.push(new StackValue(Const.T_OBJECT, value));
+                break;
+            }
+            default:
+                throw new Error("not supported LDCW type" + constant.getTag());
+        }
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/NOP.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/NOP.java
@@ -0,0 +1,23 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.nop"> Opcode definitions in The
+ *      Java Virtual Machine Specification</a>
+ */
+public class NOP extends Instruction {
+
+    public NOP(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/constants/SIPUSH.java
+++ b/src/main/java/haidnor/jvm/instruction/constants/SIPUSH.java
@@ -0,0 +1,29 @@
+package haidnor.jvm.instruction.constants;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.sipush"> Opcode definitions in
+ *      The Java Virtual Machine Specification</a>
+ */
+public class SIPUSH extends Instruction {
+
+    private final int value;
+
+    public SIPUSH(CodeStream codeStream) {
+        super(codeStream);
+        this.value = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        frame.push(new StackValue(Const.T_INT, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/control/DRETURN.java
+++ b/src/main/java/haidnor/jvm/instruction/control/DRETURN.java
@@ -0,0 +1,26 @@
+package haidnor.jvm.instruction.control;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import haidnor.jvm.util.JvmThreadHolder;
+
+public class DRETURN extends Instruction {
+
+    public DRETURN(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        // 弹出操作数栈中的值
+        StackValue stackValue = frame.pop();
+        // 将当前栈帧从 jvm 线程栈中弹出
+        JvmThreadHolder.get().pop();
+        // 将方法返回值压入前一个栈帧的操作数栈中
+        Frame topFrame = JvmThreadHolder.get().peek();
+        topFrame.push(stackValue);
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/control/FRETURN.java
+++ b/src/main/java/haidnor/jvm/instruction/control/FRETURN.java
@@ -0,0 +1,26 @@
+package haidnor.jvm.instruction.control;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import haidnor.jvm.util.JvmThreadHolder;
+
+public class FRETURN extends Instruction {
+
+    public FRETURN(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        // 弹出操作数栈中的值
+        StackValue stackValue = frame.pop();
+        // 将当前栈帧从 jvm 线程栈中弹出
+        JvmThreadHolder.get().pop();
+        // 将方法返回值压入前一个栈帧的操作数栈中
+        Frame topFrame = JvmThreadHolder.get().peek();
+        topFrame.push(stackValue);
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/control/IRETURN.java
+++ b/src/main/java/haidnor/jvm/instruction/control/IRETURN.java
@@ -0,0 +1,26 @@
+package haidnor.jvm.instruction.control;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import haidnor.jvm.util.JvmThreadHolder;
+
+public class IRETURN extends Instruction {
+
+    public IRETURN(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        // 弹出操作数栈中的值
+        StackValue stackValue = frame.pop();
+        // 将当前栈帧从 jvm 线程栈中弹出
+        JvmThreadHolder.get().pop();
+        // 将方法返回值压入前一个栈帧的操作数栈中
+        Frame topFrame = JvmThreadHolder.get().peek();
+        topFrame.push(stackValue);
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/control/LRETURN.java
+++ b/src/main/java/haidnor/jvm/instruction/control/LRETURN.java
@@ -0,0 +1,26 @@
+package haidnor.jvm.instruction.control;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import haidnor.jvm.util.JvmThreadHolder;
+
+public class LRETURN extends Instruction {
+
+    public LRETURN(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        // 弹出操作数栈中的值
+        StackValue stackValue = frame.pop();
+        // 将当前栈帧从 jvm 线程栈中弹出
+        JvmThreadHolder.get().pop();
+        // 将方法返回值压入前一个栈帧的操作数栈中
+        Frame topFrame = JvmThreadHolder.get().peek();
+        topFrame.push(stackValue);
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/control/RET.java
+++ b/src/main/java/haidnor/jvm/instruction/control/RET.java
@@ -0,0 +1,28 @@
+package haidnor.jvm.instruction.control;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+/**
+ * RET（Return）指令是 Java 虚拟机中的一条指令，用于从方法中返回并将控制流转移到调用该方法的位置。
+ * <p>
+ * RET 指令在早期版本的 Java 虚拟机中使用，但自从 Java SE 6 版本以后，它已经被废弃不再使用。取而代之的是通过 JSR 和 RET 指令的组合实现的子例程（subroutines）已经被新的字节码指令 invokedynamic 所取代。
+ * <p>
+ * RET 指令需要一个操作数，作为局部变量表（local variable table）中一个给定索引处的值。这个索引通常是由 JSR（Jump SubRoutine）指令记录的，JSR 指令在携带一个偏移量的情况下，会将指令执行的位置压入操作数栈，并跳转到指定的位置。RET 指令则使用这个记录的位置来返回。
+ * <p>
+ * 需要注意的是，由于 RET 指令被废弃，所以在现代的 Java 虚拟机中，解释器或即时编译器会将 RET 指令替换为其他的指令序列来实现相同的功能。
+ */
+public class RET extends Instruction {
+
+    public RET(CodeStream codeStream) {
+        super(codeStream);
+        throw new UnsupportedOperationException("RET");
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        throw new UnsupportedOperationException("RET");
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/control/RETURN.java
+++ b/src/main/java/haidnor/jvm/instruction/control/RETURN.java
@@ -0,0 +1,19 @@
+package haidnor.jvm.instruction.control;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+import haidnor.jvm.util.JvmThreadHolder;
+
+public class RETURN extends Instruction {
+
+    public RETURN(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        JvmThreadHolder.get().pop();
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/conversions/D2F.java
+++ b/src/main/java/haidnor/jvm/instruction/conversions/D2F.java
@@ -0,0 +1,20 @@
+
+package haidnor.jvm.instruction.conversions;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class D2F extends Instruction {
+
+    public D2F(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        double doubleVal = frame.popDouble();
+        frame.pushFloat(Double.valueOf(doubleVal).floatValue());
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/conversions/D2I.java
+++ b/src/main/java/haidnor/jvm/instruction/conversions/D2I.java
@@ -0,0 +1,19 @@
+package haidnor.jvm.instruction.conversions;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class D2I extends Instruction {
+
+    public D2I(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        double doubleVal = frame.popDouble();
+        frame.pushInt(Double.valueOf(doubleVal).intValue());
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/conversions/D2L.java
+++ b/src/main/java/haidnor/jvm/instruction/conversions/D2L.java
@@ -0,0 +1,19 @@
+package haidnor.jvm.instruction.conversions;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class D2L extends Instruction {
+
+    public D2L(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        double doubleVal = frame.popDouble();
+        frame.pushLong(Double.valueOf(doubleVal).longValue());
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/conversions/F2D.java
+++ b/src/main/java/haidnor/jvm/instruction/conversions/F2D.java
@@ -0,0 +1,19 @@
+package haidnor.jvm.instruction.conversions;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class F2D extends Instruction {
+
+    public F2D(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        float floatVal = frame.popFloat();
+        frame.pushDouble(Float.valueOf(floatVal).doubleValue());
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/conversions/F2I.java
+++ b/src/main/java/haidnor/jvm/instruction/conversions/F2I.java
@@ -0,0 +1,19 @@
+package haidnor.jvm.instruction.conversions;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class F2I extends Instruction {
+
+    public F2I(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        float floatVal = frame.popFloat();
+        frame.pushInt(Float.valueOf(floatVal).intValue());
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/conversions/F2L.java
+++ b/src/main/java/haidnor/jvm/instruction/conversions/F2L.java
@@ -0,0 +1,19 @@
+package haidnor.jvm.instruction.conversions;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class F2L extends Instruction {
+
+    public F2L(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        float floatVal = frame.popFloat();
+        frame.pushLong(Float.valueOf(floatVal).longValue());
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/conversions/I2B.java
+++ b/src/main/java/haidnor/jvm/instruction/conversions/I2B.java
@@ -0,0 +1,24 @@
+package haidnor.jvm.instruction.conversions;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+/**
+ * JVM中的I2B指令是用于执行将整数类型（int）转换为字节类型（byte）的指令。该指令将一个int类型的数值从操作数栈中弹出，并将其转换为一个字节（byte）。
+ * 然后，将转换后的字节值压入操作数栈顶。
+ * <p>
+ * byte 类型的数据是以 int 形式存在的,因此不需要做任何处理
+ */
+public class I2B extends Instruction {
+
+    public I2B(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/conversions/I2C.java
+++ b/src/main/java/haidnor/jvm/instruction/conversions/I2C.java
@@ -0,0 +1,21 @@
+package haidnor.jvm.instruction.conversions;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+/**
+ * char 类型的数据是以 int 形式存在的,因此不需要做任何处理
+ */
+public class I2C extends Instruction {
+
+    public I2C(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/conversions/I2D.java
+++ b/src/main/java/haidnor/jvm/instruction/conversions/I2D.java
@@ -0,0 +1,19 @@
+package haidnor.jvm.instruction.conversions;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class I2D extends Instruction {
+
+    public I2D(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        int intVal = frame.popInt();
+        frame.pushDouble(Integer.valueOf(intVal).doubleValue());
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/conversions/I2F.java
+++ b/src/main/java/haidnor/jvm/instruction/conversions/I2F.java
@@ -0,0 +1,19 @@
+package haidnor.jvm.instruction.conversions;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class I2F extends Instruction {
+
+    public I2F(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        int intVal = frame.popInt();
+        frame.pushFloat(Integer.valueOf(intVal).floatValue());
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/conversions/I2L.java
+++ b/src/main/java/haidnor/jvm/instruction/conversions/I2L.java
@@ -0,0 +1,19 @@
+package haidnor.jvm.instruction.conversions;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class I2L extends Instruction {
+
+    public I2L(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        int intVal = frame.popInt();
+        frame.pushLong(Integer.valueOf(intVal).longValue());
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/conversions/I2S.java
+++ b/src/main/java/haidnor/jvm/instruction/conversions/I2S.java
@@ -0,0 +1,20 @@
+package haidnor.jvm.instruction.conversions;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class I2S extends Instruction {
+
+    public I2S(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        int intVal = frame.popInt();
+        short shortValue = Integer.valueOf(intVal).shortValue();
+        frame.pushInt(((int) shortValue));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/conversions/L2D.java
+++ b/src/main/java/haidnor/jvm/instruction/conversions/L2D.java
@@ -0,0 +1,19 @@
+package haidnor.jvm.instruction.conversions;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class L2D extends Instruction {
+
+    public L2D(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        long longVal = frame.popLong();
+        frame.pushDouble(Long.valueOf(longVal).doubleValue());
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/conversions/L2F.java
+++ b/src/main/java/haidnor/jvm/instruction/conversions/L2F.java
@@ -0,0 +1,19 @@
+package haidnor.jvm.instruction.conversions;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class L2F extends Instruction {
+
+    public L2F(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        long longVal = frame.popLong();
+        frame.pushFloat(Long.valueOf(longVal).floatValue());
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/conversions/L2I.java
+++ b/src/main/java/haidnor/jvm/instruction/conversions/L2I.java
@@ -0,0 +1,19 @@
+package haidnor.jvm.instruction.conversions;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class L2I extends Instruction {
+
+    public L2I(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        long longVal = frame.popLong();
+        frame.pushInt(Long.valueOf(longVal).intValue());
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/extended/GOTO.java
+++ b/src/main/java/haidnor/jvm/instruction/extended/GOTO.java
@@ -0,0 +1,33 @@
+package haidnor.jvm.instruction.extended;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+/**
+ * Java VM opcode.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.goto"> Opcode definitions in
+ *      The Java Virtual Machine Specification</a>
+ */
+public class GOTO extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public GOTO(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        super.setOffSet(offSet);
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " "  + offSet;
+    }
+}
--- a/src/main/java/haidnor/jvm/instruction/extended/GOTO_W.java
+++ b/src/main/java/haidnor/jvm/instruction/extended/GOTO_W.java
@@ -0,0 +1,27 @@
+package haidnor.jvm.instruction.extended;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+public class GOTO_W extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public GOTO_W(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readInt(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        super.setOffSet(offSet);
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " " + offSet;
+    }
+}
--- a/src/main/java/haidnor/jvm/instruction/extended/IFNONNULL.java
+++ b/src/main/java/haidnor/jvm/instruction/extended/IFNONNULL.java
@@ -0,0 +1,33 @@
+package haidnor.jvm.instruction.extended;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+
+public class IFNONNULL extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public IFNONNULL(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        StackValue v1 = frame.pop();
+        if (v1.getValue() != null) {
+            super.setOffSet(offSet);
+        } else {
+            super.setOffSet(3);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " "  + offSet;
+    }
+}
--- a/src/main/java/haidnor/jvm/instruction/extended/IFNULL.java
+++ b/src/main/java/haidnor/jvm/instruction/extended/IFNULL.java
@@ -0,0 +1,33 @@
+package haidnor.jvm.instruction.extended;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+
+public class IFNULL extends Instruction {
+    /**
+     * 下次再执行的偏移量
+     */
+    private final int offSet;
+
+    public IFNULL(CodeStream codeStream) {
+        super(codeStream);
+        this.offSet = codeStream.readShort(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        StackValue v1 = frame.pop();
+        if (v1.getValue() == null) {
+            super.setOffSet(offSet);
+        } else {
+            super.setOffSet(3);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return super.index() + " " + this.getClass().getSimpleName() + " "  + offSet;
+    }
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/AALOAD.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/AALOAD.java
@@ -0,0 +1,24 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.rtda.heap.Instance;
+import haidnor.jvm.rtda.heap.InstanceArray;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+
+public class AALOAD extends Instruction {
+
+    public AALOAD(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        int index = frame.popInt();
+        InstanceArray array = (InstanceArray) frame.popRef();
+        Instance item = (Instance) array.items[index];
+        frame.pushRef(item);
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/ALOAD.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/ALOAD.java
@@ -0,0 +1,26 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.rtda.heap.Instance;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+
+public class ALOAD extends Instruction {
+
+    private final int index;
+
+    public ALOAD(CodeStream codeStream) {
+        super(codeStream);
+        this.index = codeStream.readUnsignedByte(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        Object value = frame.slotGetRef(index);
+        frame.push(new StackValue(Const.T_OBJECT, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/ALOAD_0.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/ALOAD_0.java
@@ -0,0 +1,22 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.rtda.heap.Instance;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+public class ALOAD_0 extends Instruction {
+
+    public ALOAD_0(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        Object value = frame.slotGetRef(0);
+        frame.push(new StackValue(Const.T_OBJECT, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/ALOAD_1.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/ALOAD_1.java
@@ -0,0 +1,22 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.rtda.heap.Instance;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+public class ALOAD_1 extends Instruction {
+
+    public ALOAD_1(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        Object value = frame.slotGetRef(1);
+        frame.push(new StackValue(Const.T_OBJECT, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/ALOAD_2.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/ALOAD_2.java
@@ -0,0 +1,21 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+public class ALOAD_2 extends Instruction {
+
+    public ALOAD_2(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        Object value = frame.slotGetRef(2);
+        frame.push(new StackValue(Const.T_OBJECT, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/ALOAD_3.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/ALOAD_3.java
@@ -0,0 +1,21 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+public class ALOAD_3 extends Instruction {
+
+    public ALOAD_3(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        Object value = frame.slotGetRef(3);
+        frame.push(new StackValue(Const.T_OBJECT, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/BALOAD.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/BALOAD.java
@@ -0,0 +1,22 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.rtda.heap.BasicTypeArray;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+
+public class BALOAD extends Instruction {
+
+    public BALOAD(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        int index = frame.popInt();
+        BasicTypeArray array = (BasicTypeArray) frame.popRef();
+        frame.pushInt(array.ints[index]);
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/CALOAD.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/CALOAD.java
@@ -0,0 +1,22 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.rtda.heap.BasicTypeArray;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+
+public class CALOAD extends Instruction {
+
+    public CALOAD(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        int index = frame.popInt();
+        BasicTypeArray array = (BasicTypeArray) frame.popRef();
+        frame.pushInt(array.ints[index]);
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/DALOAD.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/DALOAD.java
@@ -0,0 +1,22 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.rtda.heap.BasicTypeArray;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+
+public class DALOAD extends Instruction {
+
+    public DALOAD(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        int index = frame.popInt();
+        BasicTypeArray array = (BasicTypeArray) frame.popRef();
+        frame.pushDouble(array.doubles[index]);
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/DLOAD.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/DLOAD.java
@@ -0,0 +1,25 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+
+public class DLOAD extends Instruction {
+
+    private final int index;
+
+    public DLOAD(CodeStream codeStream) {
+        super(codeStream);
+        this.index = codeStream.readUnsignedByte(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        double value = frame.slotGetDouble(index);
+        frame.push(new StackValue(Const.T_DOUBLE, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/DLOAD_0.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/DLOAD_0.java
@@ -0,0 +1,21 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+public class DLOAD_0 extends Instruction {
+
+    public DLOAD_0(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        double value = frame.slotGetDouble(0);
+        frame.push(new StackValue(Const.T_DOUBLE, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/DLOAD_1.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/DLOAD_1.java
@@ -0,0 +1,21 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+public class DLOAD_1 extends Instruction {
+
+    public DLOAD_1(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        double value = frame.slotGetDouble(1);
+        frame.push(new StackValue(Const.T_DOUBLE, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/DLOAD_2.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/DLOAD_2.java
@@ -0,0 +1,21 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+public class DLOAD_2 extends Instruction {
+
+    public DLOAD_2(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        double value = frame.slotGetDouble(2);
+        frame.push(new StackValue(Const.T_DOUBLE, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/DLOAD_3.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/DLOAD_3.java
@@ -0,0 +1,21 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+public class DLOAD_3 extends Instruction {
+
+    public DLOAD_3(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        double value = frame.slotGetDouble(3);
+        frame.push(new StackValue(Const.T_DOUBLE, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/FALOAD.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/FALOAD.java
@@ -0,0 +1,22 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.rtda.heap.BasicTypeArray;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+
+public class FALOAD extends Instruction {
+
+    public FALOAD(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        int index = frame.popInt();
+        BasicTypeArray array = (BasicTypeArray) frame.popRef();
+        frame.pushFloat(array.floats[index]);
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/FLOAD.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/FLOAD.java
@@ -0,0 +1,25 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+
+public class FLOAD extends Instruction {
+
+    private final int index;
+
+    public FLOAD(CodeStream codeStream) {
+        super(codeStream);
+        this.index = codeStream.readUnsignedByte(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        float value = frame.slotGetFloat(index);
+        frame.push(new StackValue(Const.T_FLOAT, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/FLOAD_0.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/FLOAD_0.java
@@ -0,0 +1,21 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+public class FLOAD_0 extends Instruction {
+
+    public FLOAD_0(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        float value = frame.slotGetFloat(0);
+        frame.push(new StackValue(Const.T_FLOAT, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/FLOAD_1.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/FLOAD_1.java
@@ -0,0 +1,21 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+public class FLOAD_1 extends Instruction {
+
+    public FLOAD_1(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        float value = frame.slotGetFloat(1);
+        frame.push(new StackValue(Const.T_FLOAT, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/FLOAD_2.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/FLOAD_2.java
@@ -0,0 +1,21 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+public class FLOAD_2 extends Instruction {
+
+    public FLOAD_2(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        float value = frame.slotGetFloat(2);
+        frame.push(new StackValue(Const.T_FLOAT, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/FLOAD_3.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/FLOAD_3.java
@@ -0,0 +1,21 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+public class FLOAD_3 extends Instruction {
+
+    public FLOAD_3(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        float value = frame.slotGetFloat(3);
+        frame.push(new StackValue(Const.T_FLOAT, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/IALOAD.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/IALOAD.java
@@ -0,0 +1,22 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.rtda.heap.BasicTypeArray;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.util.CodeStream;
+
+
+public class IALOAD extends Instruction {
+
+    public IALOAD(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        int index = frame.popInt();
+        BasicTypeArray array = (BasicTypeArray) frame.popRef();
+        frame.pushInt(array.ints[index]);
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/ILOAD.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/ILOAD.java
@@ -0,0 +1,25 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+
+public class ILOAD extends Instruction {
+
+    private final int index;
+
+    public ILOAD(CodeStream codeStream) {
+        super(codeStream);
+        this.index = codeStream.readUnsignedByte(this);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        int value = frame.slotGetInt(index);
+        frame.push(new StackValue(Const.T_INT, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/ILOAD_0.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/ILOAD_0.java
@@ -0,0 +1,24 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.iload_n
+ */
+public class ILOAD_0 extends Instruction {
+
+    public ILOAD_0(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        int value = frame.slotGetInt(0);
+        frame.push(new StackValue(Const.T_INT, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/ILOAD_1.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/ILOAD_1.java
@@ -0,0 +1,24 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.iload_n
+ */
+public class ILOAD_1 extends Instruction {
+
+    public ILOAD_1(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        int value = frame.slotGetInt(1);
+        frame.push(new StackValue(Const.T_INT, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/ILOAD_2.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/ILOAD_2.java
@@ -0,0 +1,24 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.iload_n
+ */
+public class ILOAD_2 extends Instruction {
+
+    public ILOAD_2(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        int value = frame.slotGetInt(2);
+        frame.push(new StackValue(Const.T_INT, value));
+    }
+
+}
--- a/src/main/java/haidnor/jvm/instruction/loads/ILOAD_3.java
+++ b/src/main/java/haidnor/jvm/instruction/loads/ILOAD_3.java
@@ -0,0 +1,24 @@
+package haidnor.jvm.instruction.loads;
+
+import haidnor.jvm.instruction.Instruction;
+import haidnor.jvm.runtime.Frame;
+import haidnor.jvm.runtime.StackValue;
+import haidnor.jvm.util.CodeStream;
+import org.apache.bcel.Const;
+
+/**
+ * https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.iload_n
+ */
+public class ILOAD_3 extends Instruction {
+
+    public ILOAD_3(CodeStream codeStream) {
+        super(codeStream);
+    }
+
+    @Override
+    public void execute(Frame frame) {
+        int value = frame.slotGetInt(3);
+        frame.push(new StackValue(Const.T_INT, value));
+    }
+
+}
--- a/Show More
+++ b/Show More