From 5c02a91a35e3d7ee759ca8911a866adc8e1e4ff4 Mon Sep 17 00:00:00 2001
From: jochen <jochen@379699f6-c40d-0410-875b-85095c16579e>
Date: Fri, 9 Apr 1999 08:07:51 +0000
Subject: [PATCH] Many clean ups, use RuntimeException note that there is also
 a jasmin implementation

git-svn-id: https://svn.code.sf.net/p/jode/code/trunk@538 379699f6-c40d-0410-875b-85095c16579e
---
 jode/jode/jvm/Interpreter.java | 1333 +++++++++++++++-----------------
 1 file changed, 641 insertions(+), 692 deletions(-)

diff --git a/jode/jode/jvm/Interpreter.java b/jode/jode/jvm/Interpreter.java
index f7401b9..bbc8ea0 100644
--- a/jode/jode/jvm/Interpreter.java
+++ b/jode/jode/jvm/Interpreter.java
@@ -21,7 +21,8 @@ package jode.jvm;
 import jode.*;
 import jode.bytecode.*;
 import jode.decompiler.ClassAnalyzer;
-import java.lang.reflect.*;
+import java.lang.reflect.Array;
+import java.lang.reflect.InvocationTargetException;
 
 /**
  * This class is a java virtual machine written in java :-).  Well not
@@ -32,742 +33,690 @@ import java.lang.reflect.*;
  */
 public class Interpreter implements Opcodes {
 
-    static boolean checkType(Type type1, Class type2) {
-	if (type1 == Type.tBoolean) {
-	    return type2 == Boolean.TYPE;
-	} else if (type1 == Type.tByte) {
-	    return type2 == Byte.TYPE;
-	} else if (type1 == Type.tChar) {
-	    return type2 == Character.TYPE;
-	} else if (type1 == Type.tShort) {
-	    return type2 == Short.TYPE;
-	} else if (type1 == Type.tInt) {
-	    return type2 == Integer.TYPE;
-	} else if (type1 == Type.tLong) {
-	    return type2 == Long.TYPE;
-	} else if (type1 == Type.tFloat) {
-	    return type2 == Float.TYPE;
-	} else if (type1 == Type.tDouble) {
-	    return type2 == Double.TYPE;
-	} else if (type1 == Type.tVoid) {
-	    return type2 == Void.TYPE;
-	} else if (type1 instanceof ArrayType) {
-	    if (!type2.isArray())
-		return false;
-	    return checkType(((ArrayType)type1).getElementType(), 
-			     type2.getComponentType()); 
-	} else if (type1 instanceof ClassInterfacesType) {
-	    return type1.equals(Type.tClass(type2.getName()));
-	} else
-	    return false;
-    }
-
-    static boolean checkMethod(MethodType methodType,
-			       Class[] paramTypes, Class retType) {
-	Type[] params = methodType.getParameterTypes();
-	if (params.length != paramTypes.length)
-	    return false;
-	for (int i=0; i < params.length; i++) {
-	    if (!checkType(params[i], paramTypes[i]))
-		return false;
-	}
-	return checkType(methodType.getReturnType(), retType);
-    }
-
     public static Object interpretMethod
-	(ClassAnalyzer ca, BytecodeInfo code, Value[] locals, Value[] stack)
-	throws InterpreterException, ClassFormatException {
-	try {
+	(RuntimeEnvironment env, BytecodeInfo code, Value[] locals)
+	throws InterpreterException, InvocationTargetException {
+	Value[] stack = new Value[code.getMaxStack()];
+	for (int i=0; i< stack.length; i++)
+	    stack[i] = new Value();
+
 	Instruction pc = code.getFirstInstr();
 	int stacktop = 0;
+	big_loop:
 	for(;;) {
-	    Instruction instr = pc;
-//  	    System.err.print(instr.addr+": [");
-//  	    for (int i=0; i<stacktop; i++) {
-//  		if (i>0)
-//  		    System.err.print(",");
-//  		System.err.print(stack[i]);
-//  		if (stack[i].objectValue() instanceof char[]) {
-//  		    System.err.print(new String((char[])stack[i].objectValue()));
-//  		}
-//  	    }
-//  	    System.err.println("]");
-//  	    System.err.print("local: [");
-//  	    for (int i=0; i<locals.length; i++)
-//  		System.err.print(locals[i]+",");
-//  	    System.err.println("]");
-	    pc = instr.nextByAddr;
-	    int opcode = instr.opcode;
-	    switch (opcode) {
-	    case opc_nop:
-		break;
-	    case opc_ldc:
-	    case opc_ldc2_w: {
-		stack[stacktop++].setObject(instr.objData);
-		break;
-	    }
-	    case opc_iload: case opc_lload: 
-	    case opc_fload: case opc_dload: case opc_aload:
-		stack[stacktop++].setValue(locals[instr.localSlot]);
-		break;
-	    case opc_iaload: case opc_laload: 
-	    case opc_faload: case opc_daload: case opc_aaload:
-	    case opc_baload: case opc_caload: case opc_saload: {
-		int index = stack[--stacktop].intValue();
-		Object array = stack[--stacktop].objectValue();
-		switch(opcode) {
-		case opc_baload: 
-		    stack[stacktop++].setInt
-			(array instanceof byte[]
-			 ? ((byte[])array)[index]
-			 : ((boolean[])array)[index] ? 1 : 0);
-		case opc_caload: 
-		    stack[stacktop++].setInt(((char[])array)[index]);
-		    break;
-		case opc_saload:
-		    stack[stacktop++].setInt(((short[])array)[index]);
-		    break;
-		case opc_iaload: 
-		case opc_laload: 
-		case opc_faload: 
-		case opc_daload: 
-		case opc_aaload:
-		    stack[stacktop++].setObject(Array.get(array, index));
+	    try {
+		Instruction instr = pc;
+		System.err.print(instr.addr+": [");
+		for (int i=0; i<stacktop; i++) {
+		    if (i>0)
+			System.err.print(",");
+		    System.err.print(stack[i]);
+		    if (stack[i].objectValue() instanceof char[]) {
+			System.err.print(new String((char[])stack[i].objectValue()));
+		    }
+		}
+		System.err.println("]");
+		System.err.print("local: [");
+		for (int i=0; i<locals.length; i++)
+		    System.err.print(locals[i]+",");
+		System.err.println("]");
+
+		pc = instr.nextByAddr;
+		int opcode = instr.opcode;
+		switch (opcode) {
+		case opc_nop:
+		    break;
+		case opc_ldc:
+		    stack[stacktop++].setObject(instr.objData);
+		    break;
+		case opc_ldc2_w:
+		    stack[stacktop].setObject(instr.objData);
+		    stacktop += 2;
+		    break;
+		case opc_iload: case opc_lload: 
+		case opc_fload: case opc_dload: case opc_aload:
+		    stack[stacktop++].setValue(locals[instr.localSlot]);
+		    break;
+		case opc_iaload: case opc_laload: 
+		case opc_faload: case opc_daload: case opc_aaload:
+		case opc_baload: case opc_caload: case opc_saload: {
+		    int index = stack[--stacktop].intValue();
+		    Object array = stack[--stacktop].objectValue();
+		    Object result;
+		    try {
+			switch(opcode) {
+			case opc_baload:
+			    result = new Integer
+				(array instanceof byte[]
+				 ? ((byte[])array)[index]
+				 : ((boolean[])array)[index] ? 1 : 0);
+			    break;
+			case opc_caload: 
+			    result = new Integer(((char[])array)[index]);
+			    break;
+			case opc_saload:
+			    result = new Integer(((short[])array)[index]);
+			    break;
+			default:
+			    result = Array.get(array, index);
+			    break;
+			}
+		    } catch (NullPointerException ex) {
+			throw new InvocationTargetException(ex);
+		    } catch (ArrayIndexOutOfBoundsException ex) {
+			throw new InvocationTargetException(ex);
+		    }
+		    stack[stacktop++].setObject(result);
 		    break;
 		}
-		break;
-	    }
-	    case opc_istore: case opc_lstore: 
-	    case opc_fstore: case opc_dstore: case opc_astore:
-		locals[instr.localSlot].setValue(stack[--stacktop]);
-		break;
-	    case opc_iastore: case opc_lastore:
-	    case opc_fastore: case opc_dastore: case opc_aastore:
-	    case opc_bastore: case opc_castore: case opc_sastore: {
-		Value value = stack[--stacktop];
-		int index = stack[--stacktop].intValue();
-		Object array = stack[--stacktop].objectValue();
-		switch(opcode) {
-		case opc_bastore: 
-		    if (array instanceof byte[]) 
-			((byte[])array)[index] = (byte) value.intValue();
-		    else
-			((boolean[])array)[index] = value.intValue() != 0;
+		case opc_istore: case opc_lstore: 
+		case opc_fstore: case opc_dstore: case opc_astore:
+		    locals[instr.localSlot].setValue(stack[--stacktop]);
 		    break;
-		case opc_castore: 
-		    ((char[])array)[index] = (char) value.intValue();
+		case opc_iastore: case opc_lastore:
+		case opc_fastore: case opc_dastore: case opc_aastore:
+		case opc_bastore: case opc_castore: case opc_sastore: {
+		    Value value = stack[--stacktop];
+		    int index = stack[--stacktop].intValue();
+		    Object array = stack[--stacktop].objectValue();
+		    try {
+			switch(opcode) {
+			case opc_bastore: 
+			    if (array instanceof byte[]) 
+				((byte[])array)[index] 
+				    = (byte) value.intValue();
+			    else
+				((boolean[])array)[index]
+				    = value.intValue() != 0;
+			    break;
+			case opc_castore: 
+			    ((char[])array)[index] = (char) value.intValue();
+			    break;
+			case opc_sastore:
+			    ((short[])array)[index] = (short) value.intValue();
+			    break;
+			default:
+			    Array.set(array, index, value.objectValue());
+			}
+		    } catch (NullPointerException ex) {
+			throw new InvocationTargetException(ex);
+		    } catch (ArrayIndexOutOfBoundsException ex) {
+			throw new InvocationTargetException(ex);
+		    } catch (ArrayStoreException ex) {
+			throw new InvocationTargetException(ex);
+		    }
+		    break;
+		}
+		case opc_pop: case opc_pop2:
+		    stacktop -= opcode - (opc_pop-1);
 		    break;
-		case opc_sastore:
-		    ((short[])array)[index] = (short) value.intValue();
+		case opc_dup: case opc_dup_x1: case opc_dup_x2: {
+		    int depth = opcode - opc_dup;
+		    for (int i=0; i < depth+1; i++)
+			stack[stacktop-i].setValue(stack[stacktop-i-1]);
+		    stack[stacktop-depth-1].setValue(stack[stacktop]);
+		    stacktop++;
 		    break;
-		case opc_iastore: 
-		case opc_lastore: 
-		case opc_fastore: 
-		case opc_dastore: 
-		case opc_aastore:
-		    Array.set(array, index, value.objectValue());
 		}
-		break;
-	    }
-	    case opc_pop: case opc_pop2:
-		stacktop -= opcode - (opc_pop-1);
-		break;
-	    case opc_dup: case opc_dup_x1: case opc_dup_x2: {
-		int depth = opcode - opc_dup;
-		for (int i=0; i < depth+1; i++)
-		    stack[stacktop-i].setValue(stack[stacktop-i-1]);
-		stack[stacktop-depth-1].setValue(stack[stacktop]);
-		stacktop++;
-		break;
-	    }
-	    case opc_dup2: case opc_dup2_x1: case opc_dup2_x2: {
-		int depth = opcode - opc_dup2;
-		for (int i=0; i < depth+2; i++)
-		    stack[stacktop+1-i].setValue(stack[stacktop-1-i]);
-		stack[stacktop-depth-1].setValue(stack[stacktop+1]);
-		stack[stacktop-depth-2].setValue(stack[stacktop]);
-		stacktop += 2;
-		break;
-	    }
-	    case opc_swap: {
-		Value tmp = stack[stacktop-1];
-		stack[stacktop-1] = stack[stacktop-2];
-		stack[stacktop-2] = tmp;
-		break;
-	    }
-	    case opc_iadd: 
-		stack[stacktop-2].setInt(stack[stacktop-2].intValue()
-					 + stack[stacktop-1].intValue());
-		stacktop--;
-		break;
-	    case opc_isub: 
-		stack[stacktop-2].setInt(stack[stacktop-2].intValue()
-					 - stack[stacktop-1].intValue());
-		stacktop--;
-		break;
-	    case opc_imul: 
-		stack[stacktop-2].setInt(stack[stacktop-2].intValue()
-					 * stack[stacktop-1].intValue());
-		stacktop--;
-		break;
-	    case opc_idiv: 
-		stack[stacktop-2].setInt(stack[stacktop-2].intValue()
-					 / stack[stacktop-1].intValue());
-		stacktop--;
-		break;
-	    case opc_irem: 
-		stack[stacktop-2].setInt(stack[stacktop-2].intValue()
-					 % stack[stacktop-1].intValue());
-		stacktop--;
-		break;
+		case opc_dup2: case opc_dup2_x1: case opc_dup2_x2: {
+		    int depth = opcode - opc_dup2;
+		    for (int i=0; i < depth+2; i++)
+			stack[stacktop+1-i].setValue(stack[stacktop-1-i]);
+		    stack[stacktop-depth-1].setValue(stack[stacktop+1]);
+		    stack[stacktop-depth-2].setValue(stack[stacktop]);
+		    stacktop += 2;
+		    break;
+		}
+		case opc_swap: {
+		    Value tmp = stack[stacktop-1];
+		    stack[stacktop-1] = stack[stacktop-2];
+		    stack[stacktop-2] = tmp;
+		    break;
+		}
+		case opc_iadd: 
+		    stack[stacktop-2].setInt(stack[stacktop-2].intValue()
+					     + stack[stacktop-1].intValue());
+		    stacktop--;
+		    break;
+		case opc_isub: 
+		    stack[stacktop-2].setInt(stack[stacktop-2].intValue()
+					     - stack[stacktop-1].intValue());
+		    stacktop--;
+		    break;
+		case opc_imul: 
+		    stack[stacktop-2].setInt(stack[stacktop-2].intValue()
+					     * stack[stacktop-1].intValue());
+		    stacktop--;
+		    break;
+		case opc_idiv: 
+		    try {
+			stack[stacktop-2].setInt
+			    (stack[stacktop-2].intValue()
+			     / stack[stacktop-1].intValue());
+		    } catch (ArithmeticException ex) {
+			throw new InvocationTargetException(ex);
+		    }
+		    stacktop--;
+		    break;
+		case opc_irem: 
+		    try {
+			stack[stacktop-2].setInt
+			    (stack[stacktop-2].intValue()
+			     % stack[stacktop-1].intValue());
+		    } catch (ArithmeticException ex) {
+			throw new InvocationTargetException(ex);
+		    }
+		    stacktop--;
+		    break;
 
-	    case opc_ladd: 
-		stack[stacktop-2].setLong(stack[stacktop-2].longValue()
-					  + stack[stacktop-1].longValue());
-		stacktop--;
-		break;
-	    case opc_lsub: 
-		stack[stacktop-2].setLong(stack[stacktop-2].longValue()
-					  - stack[stacktop-1].longValue());
-		stacktop--;
-		break;
-	    case opc_lmul: 
-		stack[stacktop-2].setLong(stack[stacktop-2].longValue()
-					  * stack[stacktop-1].longValue());
-		stacktop--;
-		break;
-	    case opc_ldiv: 
-		stack[stacktop-2].setLong(stack[stacktop-2].longValue()
-					  / stack[stacktop-1].longValue());
-		stacktop--;
-		break;
-	    case opc_lrem: 
-		stack[stacktop-2].setLong(stack[stacktop-2].longValue()
-					  % stack[stacktop-1].longValue());
-		stacktop--;
-		break;
+		case opc_ladd: 
+		    stacktop-=2;
+		    stack[stacktop-2].setLong(stack[stacktop-2].longValue()
+					      + stack[stacktop].longValue());
+		    break;
+		case opc_lsub: 
+		    stacktop-=2;
+		    stack[stacktop-2].setLong(stack[stacktop-2].longValue()
+					      - stack[stacktop].longValue());
+		    break;
+		case opc_lmul: 
+		    stacktop-=2;
+		    stack[stacktop-2].setLong(stack[stacktop-2].longValue()
+					      * stack[stacktop].longValue());
+		    break;
+		case opc_ldiv: 
+		    stacktop-=2;
+		    try {
+			stack[stacktop-2].setLong
+			    (stack[stacktop-2].longValue()
+			     / stack[stacktop].longValue());
+		    } catch (ArithmeticException ex) {
+			throw new InvocationTargetException(ex);
+		    }
+		    break;
+		case opc_lrem: 
+		    stacktop-=2;
+		    try {
+			stack[stacktop-2].setLong
+			    (stack[stacktop-2].longValue()
+			     % stack[stacktop].longValue());
+		    } catch (ArithmeticException ex) {
+			throw new InvocationTargetException(ex);
+		    }
+		    break;
 
-	    case opc_fadd: 
-		stack[stacktop-2].setFloat(stack[stacktop-2].floatValue()
-					   + stack[stacktop-1].floatValue());
-		stacktop--;
-		break;
-	    case opc_fsub: 
-		stack[stacktop-2].setFloat(stack[stacktop-2].floatValue()
-					   - stack[stacktop-1].floatValue());
-		stacktop--;
-		break;
-	    case opc_fmul: 
-		stack[stacktop-2].setFloat(stack[stacktop-2].floatValue()
-					   * stack[stacktop-1].floatValue());
-		stacktop--;
-		break;
-	    case opc_fdiv: 
-		stack[stacktop-2].setFloat(stack[stacktop-2].floatValue()
-					   / stack[stacktop-1].floatValue());
-		stacktop--;
-		break;
-	    case opc_frem: 
-		stack[stacktop-2].setFloat(stack[stacktop-2].floatValue()
-					   % stack[stacktop-1].floatValue());
-		stacktop--;
-		break;
+		case opc_fadd: 
+		    stack[stacktop-2].setFloat(stack[stacktop-2].floatValue()
+					       + stack[stacktop-1].floatValue());
+		    stacktop--;
+		    break;
+		case opc_fsub: 
+		    stack[stacktop-2].setFloat(stack[stacktop-2].floatValue()
+					       - stack[stacktop-1].floatValue());
+		    stacktop--;
+		    break;
+		case opc_fmul: 
+		    stack[stacktop-2].setFloat(stack[stacktop-2].floatValue()
+					       * stack[stacktop-1].floatValue());
+		    stacktop--;
+		    break;
+		case opc_fdiv: 
+		    stack[stacktop-2].setFloat(stack[stacktop-2].floatValue()
+					       / stack[stacktop-1].floatValue());
+		    stacktop--;
+		    break;
+		case opc_frem: 
+		    stack[stacktop-2].setFloat(stack[stacktop-2].floatValue()
+					       % stack[stacktop-1].floatValue());
+		    stacktop--;
+		    break;
 
-	    case opc_dadd: 
-		stack[stacktop-2].setDouble(stack[stacktop-2].doubleValue()
-					    + stack[stacktop-1].doubleValue());
-		stacktop--;
-		break;
-	    case opc_dsub: 
-		stack[stacktop-2].setDouble(stack[stacktop-2].doubleValue()
-					    - stack[stacktop-1].doubleValue());
-		stacktop--;
-		break;
-	    case opc_dmul: 
-		stack[stacktop-2].setDouble(stack[stacktop-2].doubleValue()
-					    * stack[stacktop-1].doubleValue());
-		stacktop--;
-		break;
-	    case opc_ddiv: 
-		stack[stacktop-2].setDouble(stack[stacktop-2].doubleValue()
-					    / stack[stacktop-1].doubleValue());
-		stacktop--;
-		break;
-	    case opc_drem: 
-		stack[stacktop-2].setDouble(stack[stacktop-2].doubleValue()
-					    % stack[stacktop-1].doubleValue());
-		stacktop--;
-		break;
+		case opc_dadd: 
+		    stacktop-=2;
+		    stack[stacktop-2].setDouble(stack[stacktop-2].doubleValue()
+						+ stack[stacktop].doubleValue());
+		    break;
+		case opc_dsub: 
+		    stacktop-=2;
+		    stack[stacktop-2].setDouble(stack[stacktop-2].doubleValue()
+						- stack[stacktop].doubleValue());
+		    break;
+		case opc_dmul: 
+		    stacktop-=2;
+		    stack[stacktop-2].setDouble(stack[stacktop-2].doubleValue()
+						* stack[stacktop].doubleValue());
+		    break;
+		case opc_ddiv: 
+		    stacktop-=2;
+		    stack[stacktop-2].setDouble(stack[stacktop-2].doubleValue()
+						/ stack[stacktop].doubleValue());
+		    break;
+		case opc_drem: 
+		    stacktop-=2;
+		    stack[stacktop-2].setDouble(stack[stacktop-2].doubleValue()
+						% stack[stacktop].doubleValue());
+		    break;
 
-	    case opc_ineg: 
-		stack[stacktop-1].setInt(-stack[stacktop-1].intValue());
-		break;
-	    case opc_lneg: 
-		stack[stacktop-1].setLong(-stack[stacktop-1].longValue());
-		break;
-	    case opc_fneg: 
-		stack[stacktop-1].setFloat(-stack[stacktop-1].floatValue());
-		break;
-	    case opc_dneg: 
-		stack[stacktop-1].setDouble(-stack[stacktop-1].doubleValue());
-		break;
+		case opc_ineg: 
+		    stack[stacktop-1].setInt(-stack[stacktop-1].intValue());
+		    break;
+		case opc_lneg: 
+		    stack[stacktop-2].setLong(-stack[stacktop-2].longValue());
+		    break;
+		case opc_fneg: 
+		    stack[stacktop-1].setFloat(-stack[stacktop-1].floatValue());
+		    break;
+		case opc_dneg: 
+		    stack[stacktop-2].setDouble(-stack[stacktop-2].doubleValue());
+		    break;
 
-	    case opc_ishl:
-		stack[stacktop-2].setInt(stack[stacktop-2].intValue()
-					 << stack[stacktop-1].intValue());
-		stacktop--;
-		break;
-	    case opc_ishr:
-		stack[stacktop-2].setInt(stack[stacktop-2].intValue()
-					 >> stack[stacktop-1].intValue());
-		stacktop--;
-		break;
-	    case opc_iushr:
-		stack[stacktop-2].setInt(stack[stacktop-2].intValue()
-					 >>> stack[stacktop-1].intValue());
-		stacktop--;
-		break;
-	    case opc_iand:
-		stack[stacktop-2].setInt(stack[stacktop-2].intValue()
-					 & stack[stacktop-1].intValue());
-		stacktop--;
-		break;
-	    case opc_ior :
-		stack[stacktop-2].setInt(stack[stacktop-2].intValue()
-					 | stack[stacktop-1].intValue());
-		stacktop--;
-		break;
-	    case opc_ixor:
-		stack[stacktop-2].setInt(stack[stacktop-2].intValue()
-					 ^ stack[stacktop-1].intValue());
-		stacktop--;
-		break;
+		case opc_ishl:
+		    stack[stacktop-2].setInt(stack[stacktop-2].intValue()
+					     << stack[stacktop-1].intValue());
+		    stacktop--;
+		    break;
+		case opc_ishr:
+		    stack[stacktop-2].setInt(stack[stacktop-2].intValue()
+					     >> stack[stacktop-1].intValue());
+		    stacktop--;
+		    break;
+		case opc_iushr:
+		    stack[stacktop-2].setInt(stack[stacktop-2].intValue()
+					     >>> stack[stacktop-1].intValue());
+		    stacktop--;
+		    break;
+		case opc_iand:
+		    stack[stacktop-2].setInt(stack[stacktop-2].intValue()
+					     & stack[stacktop-1].intValue());
+		    stacktop--;
+		    break;
+		case opc_ior :
+		    stack[stacktop-2].setInt(stack[stacktop-2].intValue()
+					     | stack[stacktop-1].intValue());
+		    stacktop--;
+		    break;
+		case opc_ixor:
+		    stack[stacktop-2].setInt(stack[stacktop-2].intValue()
+					     ^ stack[stacktop-1].intValue());
+		    stacktop--;
+		    break;
 
-	    case opc_lshl:
-		stack[stacktop-2].setLong(stack[stacktop-2].longValue()
-					  << stack[stacktop-1].longValue());
-		stacktop--;
-		break;
-	    case opc_lshr:
-		stack[stacktop-2].setLong(stack[stacktop-2].longValue()
-					  >> stack[stacktop-1].longValue());
-		stacktop--;
-		break;
-	    case opc_lushr:
-		stack[stacktop-2].setLong(stack[stacktop-2].longValue()
-					  >>> stack[stacktop-1].longValue());
-		stacktop--;
-		break;
-	    case opc_land:
-		stack[stacktop-2].setLong(stack[stacktop-2].longValue()
-					  & stack[stacktop-1].longValue());
-		stacktop--;
-		break;
-	    case opc_lor :
-		stack[stacktop-2].setLong(stack[stacktop-2].longValue()
-					  | stack[stacktop-1].longValue());
-		stacktop--;
-		break;
-	    case opc_lxor:
-		stack[stacktop-2].setLong(stack[stacktop-2].longValue()
-					  ^ stack[stacktop-1].longValue());
-		stacktop--;
-		break;
+		case opc_lshl:
+		    stack[stacktop-2].setLong(stack[stacktop-2].longValue()
+					      << stack[stacktop-1].longValue());
+		    stacktop--;
+		    break;
+		case opc_lshr:
+		    stack[stacktop-2].setLong(stack[stacktop-2].longValue()
+					      >> stack[stacktop-1].longValue());
+		    stacktop--;
+		    break;
+		case opc_lushr:
+		    stack[stacktop-2].setLong(stack[stacktop-2].longValue()
+					      >>> stack[stacktop-1].longValue());
+		    stacktop--;
+		    break;
+		case opc_land:
+		    stack[stacktop-2].setLong(stack[stacktop-2].longValue()
+					      & stack[stacktop-1].longValue());
+		    stacktop--;
+		    break;
+		case opc_lor :
+		    stack[stacktop-2].setLong(stack[stacktop-2].longValue()
+					      | stack[stacktop-1].longValue());
+		    stacktop--;
+		    break;
+		case opc_lxor:
+		    stack[stacktop-2].setLong(stack[stacktop-2].longValue()
+					      ^ stack[stacktop-1].longValue());
+		    stacktop--;
+		    break;
 
-	    case opc_iinc:
-		locals[instr.localSlot].setInt
-		    (locals[instr.localSlot].intValue() + instr.intData);
-		break;
-	    case opc_i2l:
-		stack[stacktop-1]
-		    .setLong((long)stack[stacktop-1].intValue());
-		break;
-	    case opc_i2f: 
-		stack[stacktop-1]
-		    .setFloat((float)stack[stacktop-1].intValue());
-		break;
-	    case opc_i2d:
-		stack[stacktop-1]
-		    .setDouble((double)stack[stacktop-1].intValue());
-		break;
+		case opc_iinc:
+		    locals[instr.localSlot].setInt
+			(locals[instr.localSlot].intValue() + instr.intData);
+		    break;
+		case opc_i2l:
+		    stack[stacktop-1]
+			.setLong((long)stack[stacktop-1].intValue());
+		    break;
+		case opc_i2f: 
+		    stack[stacktop-1]
+			.setFloat((float)stack[stacktop-1].intValue());
+		    break;
+		case opc_i2d:
+		    stack[stacktop-1]
+			.setDouble((double)stack[stacktop-1].intValue());
+		    break;
 
-	    case opc_l2i:
-		stack[stacktop-1]
-		    .setInt((int)stack[stacktop-1].longValue());
-		break;
-	    case opc_l2f: 
-		stack[stacktop-1]
-		    .setFloat((float)stack[stacktop-1].longValue());
-		break;
-	    case opc_l2d:
-		stack[stacktop-1]
-		    .setDouble((double)stack[stacktop-1].longValue());
-		break;
+		case opc_l2i:
+		    stack[stacktop-1]
+			.setInt((int)stack[stacktop-1].longValue());
+		    break;
+		case opc_l2f: 
+		    stack[stacktop-1]
+			.setFloat((float)stack[stacktop-1].longValue());
+		    break;
+		case opc_l2d:
+		    stack[stacktop-1]
+			.setDouble((double)stack[stacktop-1].longValue());
+		    break;
 
-	    case opc_f2i: 
-		stack[stacktop-1]
-		    .setInt((int)stack[stacktop-1].floatValue());
-		break;
-	    case opc_f2l:
-		stack[stacktop-1]
-		    .setLong((long)stack[stacktop-1].floatValue());
-		break;
-	    case opc_f2d:
-		stack[stacktop-1]
-		    .setDouble((double)stack[stacktop-1].floatValue());
-		break;
+		case opc_f2i: 
+		    stack[stacktop-1]
+			.setInt((int)stack[stacktop-1].floatValue());
+		    break;
+		case opc_f2l:
+		    stack[stacktop-1]
+			.setLong((long)stack[stacktop-1].floatValue());
+		    break;
+		case opc_f2d:
+		    stack[stacktop-1]
+			.setDouble((double)stack[stacktop-1].floatValue());
+		    break;
 
-	    case opc_d2i:
-		stack[stacktop-1]
-		    .setInt((int)stack[stacktop-1].doubleValue());
-		break;
-	    case opc_d2l:
-		stack[stacktop-1]
-		    .setLong((long)stack[stacktop-1].doubleValue());
-		break;
-	    case opc_d2f: 
-		stack[stacktop-1]
-		    .setFloat((float)stack[stacktop-1].doubleValue());
-		break;
+		case opc_d2i:
+		    stack[stacktop-1]
+			.setInt((int)stack[stacktop-1].doubleValue());
+		    break;
+		case opc_d2l:
+		    stack[stacktop-1]
+			.setLong((long)stack[stacktop-1].doubleValue());
+		    break;
+		case opc_d2f: 
+		    stack[stacktop-1]
+			.setFloat((float)stack[stacktop-1].doubleValue());
+		    break;
 
-	    case opc_i2b: 
-		stack[stacktop-1]
-		    .setInt((byte)stack[stacktop-1].intValue());
-		break;		
-	    case opc_i2c: 
-		stack[stacktop-1]
-		    .setInt((char)stack[stacktop-1].intValue());
-		break;
-	    case opc_i2s:
-		stack[stacktop-1]
-		    .setInt((short)stack[stacktop-1].intValue());
-		break;
-	    case opc_lcmp: {
-		long val1 = stack[stacktop-2].longValue();
-		long val2 = stack[--stacktop].longValue();
-		stack[stacktop-1].setInt
-		    (val1 == val2 ? 0 : val1 < val2 ? -1 : 1);
-		break;
-	    }
-	    case opc_fcmpl: case opc_fcmpg: {
-		float val1 = stack[stacktop-2].floatValue();
-		float val2 = stack[--stacktop].floatValue();
-		stack[stacktop-1].setInt
-		    (val1 == val2 ? 0
-		     : ( opcode == opc_fcmpg
-			 ? (val1 < val2 ? -1 :  1)
-			 : (val1 > val2 ?  1 : -1)));
-		break;
-	    }
-	    case opc_dcmpl: case opc_dcmpg: {
-		double val1 = stack[stacktop-2].doubleValue();
-		double val2 = stack[--stacktop].doubleValue();
-		stack[stacktop-1].setInt
-		    (val1 == val2 ? 0
-		     : ( opcode == opc_dcmpg
-			 ? (val1 < val2 ? -1 :  1)
-			 : (val1 > val2 ?  1 : -1)));
-		break;
-	    }
-	    case opc_ifeq: case opc_ifne: 
-	    case opc_iflt: case opc_ifge: 
-	    case opc_ifgt: case opc_ifle:
-	    case opc_if_icmpeq: case opc_if_icmpne:
-	    case opc_if_icmplt: case opc_if_icmpge: 
-	    case opc_if_icmpgt: case opc_if_icmple: 
-	    case opc_if_acmpeq: case opc_if_acmpne:
-	    case opc_ifnull: case opc_ifnonnull: {
-		int value;
-		if (opcode >= opc_if_acmpeq) {
-		    if (opcode >= opc_ifnull) {
-			value = 
-			    stack[--stacktop].objectValue() == null ? 0 : 1;
-			opcode += opc_ifeq - opc_ifnull;
+		case opc_i2b: 
+		    stack[stacktop-1]
+			.setInt((byte)stack[stacktop-1].intValue());
+		    break;		
+		case opc_i2c: 
+		    stack[stacktop-1]
+			.setInt((char)stack[stacktop-1].intValue());
+		    break;
+		case opc_i2s:
+		    stack[stacktop-1]
+			.setInt((short)stack[stacktop-1].intValue());
+		    break;
+		case opc_lcmp: {
+		    long val1 = stack[stacktop-2].longValue();
+		    long val2 = stack[--stacktop].longValue();
+		    stack[stacktop-1].setInt
+			(val1 == val2 ? 0 : val1 < val2 ? -1 : 1);
+		    break;
+		}
+		case opc_fcmpl: case opc_fcmpg: {
+		    float val1 = stack[stacktop-2].floatValue();
+		    float val2 = stack[--stacktop].floatValue();
+		    stack[stacktop-1].setInt
+			(val1 == val2 ? 0
+			 : ( opcode == opc_fcmpg
+			     ? (val1 < val2 ? -1 :  1)
+			     : (val1 > val2 ?  1 : -1)));
+		    break;
+		}
+		case opc_dcmpl: case opc_dcmpg: {
+		    double val1 = stack[stacktop-2].doubleValue();
+		    double val2 = stack[--stacktop].doubleValue();
+		    stack[stacktop-1].setInt
+			(val1 == val2 ? 0
+			 : ( opcode == opc_dcmpg
+			     ? (val1 < val2 ? -1 :  1)
+			     : (val1 > val2 ?  1 : -1)));
+		    break;
+		}
+		case opc_ifeq: case opc_ifne: 
+		case opc_iflt: case opc_ifge: 
+		case opc_ifgt: case opc_ifle:
+		case opc_if_icmpeq: case opc_if_icmpne:
+		case opc_if_icmplt: case opc_if_icmpge: 
+		case opc_if_icmpgt: case opc_if_icmple: 
+		case opc_if_acmpeq: case opc_if_acmpne:
+		case opc_ifnull: case opc_ifnonnull: {
+		    int value;
+		    if (opcode >= opc_if_acmpeq) {
+			if (opcode >= opc_ifnull) {
+			    value = 
+				stack[--stacktop].objectValue() == null ? 0 : 1;
+			    opcode += opc_ifeq - opc_ifnull;
+			} else {
+			    value = 
+				stack[--stacktop].objectValue()
+				== stack[--stacktop].objectValue() ? 0 : 1;
+			    opcode += opc_ifeq - opc_if_acmpeq;
+			}
 		    } else {
-			value = 
-			    stack[--stacktop].objectValue()
-			    == stack[--stacktop].objectValue() ? 0 : 1;
-			opcode += opc_ifeq - opc_if_acmpeq;
-		    }
-		} else {
-		    value = stack[--stacktop].intValue();
-		    if (opcode >= opc_if_icmpeq) {
-			int val1 = stack[--stacktop].intValue();
-			value = (val1 == value ? 0
-				 : val1 < value ? -1 : 1);
-			opcode += opc_ifeq - opc_if_icmpeq;
+			value = stack[--stacktop].intValue();
+			if (opcode >= opc_if_icmpeq) {
+			    int val1 = stack[--stacktop].intValue();
+			    value = (val1 == value ? 0
+				     : val1 < value ? -1 : 1);
+			    opcode += opc_ifeq - opc_if_icmpeq;
+			}
 		    }
+		    if (value > 0 && (opcode == opc_ifgt || opcode == opc_ifge)
+			|| value < 0 && (opcode == opc_iflt || opcode == opc_ifle)
+			|| value == 0 && (opcode == opc_ifge || opcode == opc_ifle
+					  || opcode == opc_ifeq))
+			pc = instr.succs[0];
+		    break;
 		}
-		if (value > 0 && (opcode == opc_ifgt || opcode == opc_ifge)
-		    || value < 0 && (opcode == opc_iflt || opcode == opc_ifle)
-		    || value == 0 && (opcode == opc_ifge || opcode == opc_ifle
-				      || opcode == opc_ifeq))
+		case opc_jsr:
+		case opc_jsr_w:
+		    stack[stacktop++].setObject(instr);
+		    /* fall through */
+		case opc_goto:
+		case opc_goto_w:
 		    pc = instr.succs[0];
-		break;
-	    }
-	    case opc_jsr:
-	    case opc_jsr_w:
-		stack[stacktop++].setObject(instr);
-		/* fall through */
-	    case opc_goto:
-	    case opc_goto_w:
-		pc = instr.succs[0];
-		break;
-	    case opc_ret:
-		pc = (Instruction)locals[instr.localSlot].objectValue();
-		break;
-	    case opc_tableswitch: {
-		int value = stack[--stacktop].intValue();
-		int low  = instr.intData;
-		if (value >= low && value <= low + instr.succs.length - 2)
-		    pc = instr.succs[value - low];
-		else
-		    pc = instr.succs[instr.succs.length-1];
-		break;
-            }
-	    case opc_lookupswitch: {
-		int value = stack[--stacktop].intValue();
-		int[] values = (int[]) instr.objData;
-		pc = instr.succs[values.length];
-		for (int i=0; i< values.length; i++) {
-		    if (values[i] == value) {
-			pc = instr.succs[i];
-			break;
-		    }
+		    break;
+		case opc_ret:
+		    pc = (Instruction)locals[instr.localSlot].objectValue();
+		    break;
+		case opc_tableswitch: {
+		    int value = stack[--stacktop].intValue();
+		    int low  = instr.intData;
+		    if (value >= low && value <= low + instr.succs.length - 2)
+			pc = instr.succs[value - low];
+		    else
+			pc = instr.succs[instr.succs.length-1];
+		    break;
 		}
-		break;
-            }
-	    case opc_ireturn: case opc_lreturn: 
-	    case opc_freturn: case opc_dreturn: case opc_areturn:
-		return stack[--stacktop].objectValue();
-	    case opc_return:
-		return Void.TYPE;
-	    case opc_getstatic:
-	    case opc_getfield:
-	    case opc_putstatic:
-	    case opc_putfield:
-		throw new InterpreterException
-		    ("Implement get/put-static/field?");
-	    case opc_invokevirtual:
-	    case opc_invokespecial:
-	    case opc_invokestatic :
-	    case opc_invokeinterface: {
-		Reference ref = (Reference) instr.objData;
-		
-		if (ref.getClazz().equals(ca.getClazz().getName())) {
-		    MethodType mt = (MethodType) Type.tType(ref.getType());
-		    BytecodeInfo info = ca.getMethod(ref.getName(), mt)
-			.getCode().getBytecodeInfo();
-		    Value[] newLocals = new Value[info.getMaxLocals()];
-		    for (int i=0; i< newLocals.length; i++)
-			newLocals[i] = new Value();
-		    Value[] newStack = new Value[info.getMaxStack()];
-		    for (int i=0; i< newStack.length; i++)
-			newStack[i] = new Value();
-		    int param = mt.getParameterTypes().length;
-		    int slot = 0;
-		    if (opcode != opc_invokestatic)
-			newLocals[slot++].setValue(stack[stacktop-param-1]);
-		    for (int i = 0; i < param; i++) {
-			newLocals[slot].setValue(stack[stacktop-param+i]);
-			slot += mt.getParameterTypes()[i].stackSize();
-		    }
-		    Object result = interpretMethod(ca, info, 
-						    newLocals, newStack);
-		    if (mt.getReturnType() != Type.tVoid)
-			stack[stacktop++].setObject(result);
-		} else {
-		    Class clazz;
-		    try {
-			clazz = Class.forName(ref.getClazz());
-		    } catch (ClassNotFoundException ex) {
-			throw new InterpreterException
-			    ("Class "+ref.getClazz()+" not found");
-		    }
-		    try {
-			if (ref.getName().equals("<init>")) {
-			    Constructor[] cs = clazz.getConstructors();
-			    Constructor c = null;
-			    for (int i=0; i< cs.length; i++) {
-				if (checkMethod((MethodType) 
-						Type.tType(ref.getType()), 
-						cs[i].getParameterTypes(), 
-						Void.TYPE)) {
-				    c = cs[i];
-				    break;
-				}
-			    }
-			    if (c == null)
-				throw new InterpreterException
-				    ("Constructor " + ref + " not found.");
-			    Object[] args
-				= new Object[c.getParameterTypes().length];
-			    for (int i=args.length - 1; i >= 0; i--)
-				args[i] = stack[--stacktop].objectValue();
-			    NewObject newObj = stack[--stacktop].getNewObject();
-			    if (!newObj.getType().equals(ref.getClazz()))
-				throw new InterpreterException
-				    ("constructor called on wrong type");
-			    newObj.setObject(c.newInstance(args));
-			} else {
-			    Method[] ms = clazz.getMethods();
-			    Method m = null;
-			    for (int i=0; i< ms.length; i++) {
-				if (ms[i].getName().equals(ref.getName())) {
-				    if (checkMethod((MethodType) 
-						    Type.tType(ref.getType()),
-						    ms[i].getParameterTypes(), 
-						    ms[i].getReturnType())) {
-					m = ms[i];
-					break;
-				    }
-				}
-			    }
-			    if (m == null)
-				throw new InterpreterException
-				    ("Method " + ref + " not found.");
-			    Object obj = null;
-			    Object[] args 
-				= new Object[m.getParameterTypes().length];
-			    for (int i=args.length - 1; i >= 0; i--)
-				args[i] = stack[--stacktop].objectValue();
-			    if (opcode != opc_invokestatic)
-				obj = stack[--stacktop].objectValue();
-			    /* special and constructor? XXX*/
-			Object result = m.invoke(obj, args);
-			if (m.getReturnType() != Void.TYPE)
-			    stack[stacktop++].setObject(result);
+		case opc_lookupswitch: {
+		    int value = stack[--stacktop].intValue();
+		    int[] values = (int[]) instr.objData;
+		    pc = instr.succs[values.length];
+		    for (int i=0; i< values.length; i++) {
+			if (values[i] == value) {
+			    pc = instr.succs[i];
+			    break;
 			}
-		    } catch (IllegalAccessException ex) {
-			throw new InterpreterException
-			    ("Method " + ref + " not accessible");
-		    } catch (InstantiationException ex) {
-			throw new InterpreterException
-			    ("InstantiationException in " + ref + ".");
-		    } catch (InvocationTargetException ex) {
-			throw new InterpreterException
-			    ("Method " + ref + " throwed an exception");
-			/*XXX exception handler?*/
 		    }
+		    break;
 		}
-		break;
-	    }
-	    case opc_new: {
-		String clazz = (String) instr.objData;
-		stack[stacktop++].setNewObject(new NewObject(clazz));
-		break;
-	    }
-	    case opc_newarray: {
-		int length = stack[--stacktop].intValue();
-		switch (instr.intData) {
-		case  4: 
-		    stack[stacktop++].setObject(new boolean[length]); 
+		case opc_ireturn: case opc_lreturn: 
+		case opc_freturn: case opc_dreturn: case opc_areturn:
+		    return stack[--stacktop].objectValue();
+		case opc_return:
+		    return Void.TYPE;
+		case opc_getstatic:
+		    stack[stacktop++].setObject
+			(env.getField((Reference) instr.objData, null));
 		    break;
-		case  5:
-		    stack[stacktop++].setObject(new char[length]); 
+		case opc_getfield: {
+		    Object cls = stack[--stacktop];
+		    if (cls == null)
+			throw new InvocationTargetException
+			    (new NullPointerException());
+		    stack[stacktop++].setObject
+			(env.getField((Reference) instr.objData, cls));
 		    break;
-		case  6:
-		    stack[stacktop++].setObject(new float[length]); 
+		}
+		case opc_putstatic: {
+		    Object value = stack[--stacktop];
+		    env.putField((Reference) instr.objData, null, value);
 		    break;
-		case  7:
-		    stack[stacktop++].setObject(new double[length]); 
+		}
+		case opc_putfield: {
+		    Object value = stack[--stacktop];
+		    Object cls = stack[--stacktop];
+		    if (cls == null)
+			throw new InvocationTargetException
+			    (new NullPointerException());
+		    env.putField((Reference) instr.objData, cls, value);
 		    break;
-		case  8:
-		    stack[stacktop++].setObject(new byte[length]); 
+		}
+		case opc_invokevirtual:
+		case opc_invokespecial:
+		case opc_invokestatic :
+		case opc_invokeinterface: {
+		    Reference ref = (Reference) instr.objData;
+		    MethodType mt = (MethodType) Type.tType(ref.getType());
+		    Object[] args = new Object[mt.getParameterTypes().length];
+		    for (int i=args.length - 1; i >= 0; i--) {
+			stacktop -= mt.getParameterTypes()[i].stackSize();
+			args[i] = stack[stacktop].objectValue();
+		    }
+		
+		    Object result = null;
+		    if (ref.getName().equals("<init>")) {
+			NewObject newObj = stack[--stacktop].getNewObject();
+//  			if (!newObj.getType().equals(ref.getClazz()))
+//  			    throw new InterpreterException
+//  				("constructor called on wrong type");
+			newObj.setObject(env.invokeConstructor(ref, args));
+		    } else if (opcode == opc_invokestatic) {
+			result = env.invokeMethod(ref, false, null, args);
+		    } else {
+			Object cls = stack[--stacktop].objectValue();
+			if (cls == null)
+			    throw new InvocationTargetException
+				(new NullPointerException());
+			result = env.invokeMethod
+			    (ref, opcode != opc_invokespecial, cls, args);
+		    }
+		    if (mt.getReturnType() != Type.tVoid) {
+			stack[stacktop].setObject(result);
+			stacktop += mt.getReturnType().stackSize();
+		    }
 		    break;
-		case  9:
-		    stack[stacktop++].setObject(new short[length]); 
+		}
+		case opc_new: {
+		    String clazz = (String) instr.objData;
+		    stack[stacktop++].setNewObject(new NewObject(clazz));
 		    break;
-		case 10:
-		    stack[stacktop++].setObject(new int[length]); 
+		}
+		case opc_newarray: {
+		    int length = stack[--stacktop].intValue();
+		    try {
+			switch (instr.intData) {
+			case  4: 
+			    stack[stacktop++].setObject(new boolean[length]); 
+			    break;
+			case  5:
+			    stack[stacktop++].setObject(new char[length]); 
+			    break;
+			case  6:
+			    stack[stacktop++].setObject(new float[length]); 
+			    break;
+			case  7:
+			    stack[stacktop++].setObject(new double[length]); 
+			    break;
+			case  8:
+			    stack[stacktop++].setObject(new byte[length]); 
+			    break;
+			case  9:
+			    stack[stacktop++].setObject(new short[length]); 
+			    break;
+			case 10:
+			    stack[stacktop++].setObject(new int[length]); 
+			    break;
+			case 11:
+			    stack[stacktop++].setObject(new long[length]); 
+			    break;
+			default:
+			    throw new AssertError("Invalid newarray operand");
+			}
+		    } catch (NegativeArraySizeException ex) {
+			throw new InvocationTargetException(ex);
+		    }
 		    break;
-		case 11:
-		    stack[stacktop++].setObject(new long[length]); 
+		}
+		case opc_anewarray: {
+		    int length = stack[--stacktop].intValue();
+		    try {
+			stack[stacktop++].setObject
+			    (env.newArray((String) instr.objData, 
+					  new int[] { length }));
+		    } catch (NegativeArraySizeException ex) {
+			throw new InvocationTargetException(ex);
+		    }
 		    break;
-		default:
-		    throw new ClassFormatException("Invalid newarray operand");
 		}
-		break;
-	    }
-	    case opc_anewarray: {
-		int length = stack[--stacktop].intValue();
-		Class clazz;
-		try {
-		    clazz = Class.forName((String) instr.objData);
-		} catch (ClassNotFoundException ex) {
-		    throw new InterpreterException
-			("Class "+ex.getMessage()+" not found");
+		case opc_arraylength: {
+		    Object array = stack[--stacktop].objectValue();
+		    stack[stacktop++].setInt(Array.getLength(array));
+		    break;
 		}
-		stack[stacktop++].setObject(Array.newInstance(clazz, length));
-		break;
-	    }
-	    case opc_arraylength: {
-		Object array = stack[--stacktop].objectValue();
-		stack[stacktop++].setInt(Array.getLength(array));
-                break;
-	    }
-	    case opc_athrow:
-		/*XXX Throw and catch ?? */
-		throw new InterpreterException("Throw not implemented");
-	    case opc_checkcast: {
-		Class clazz;
-		try {
-		    clazz = Class.forName((String) instr.objData);
-		} catch (ClassNotFoundException ex) {
-		    throw new InterpreterException
-			("Class "+ex.getMessage()+" not found");
+		case opc_athrow: {
+		    Throwable exc = 
+			(Throwable) stack[--stacktop].objectValue();
+		    throw new InvocationTargetException
+			(exc == null ? new NullPointerException() : exc);
 		}
-		Object obj = stack[stacktop-1].objectValue();
-		if (obj != null && !clazz.isInstance(obj)) {
-		    /*XXX*/
-		    throw new InterpreterException
-			("Throw ClassCastException not implemented");
+		case opc_checkcast: {
+		    Object obj = stack[stacktop-1].objectValue();
+		    if (obj != null
+			&& !env.instanceOf(obj, (String) instr.objData))
+			throw new InvocationTargetException
+			    (new ClassCastException(obj.getClass().getName()));
+		    break;
 		}
-		break;
-	    }
-	    case opc_instanceof: {
-		Class clazz;
-		try {
-		    clazz = Class.forName((String) instr.objData);
-		} catch (ClassNotFoundException ex) {
-		    throw new InterpreterException
-			("Class "+ex.getMessage()+" not found");
+		case opc_instanceof: {
+		    Object obj = stack[--stacktop].objectValue();
+		    stack[stacktop++].setInt
+			(env.instanceOf(obj, (String) instr.objData) ? 1 : 0);
+		    break;
 		}
-		Object obj = stack[--stacktop].objectValue();
-		if (obj != null && !clazz.isInstance(obj)) {
-		    /*XXX*/
-		    throw new InterpreterException
-			("Throw ClassCastException not implemented");
+		case opc_monitorenter:
+		    env.enterMonitor(stack[--stacktop].objectValue());
+		    break;
+		case opc_monitorexit:
+		    env.exitMonitor(stack[--stacktop].objectValue());
+		    break;
+		case opc_multianewarray: {
+		    int dimension = instr.intData;
+		    int[] dims = new int[dimension];
+		    for (int i=dimension - 1; i >= 0; i--)
+			dims[i-1] = stack[--stacktop].intValue();
+		    try {
+			stack[stacktop++].setObject
+			    (env.newArray((String) instr.objData, dims));
+		    } catch (NegativeArraySizeException ex) {
+			throw new InvocationTargetException(ex);
+		    }
+		    break;
 		}
-		break;
-	    }
-	    case opc_monitorenter:
-	    case opc_monitorexit:
-		throw new InterpreterException
-		    ("MonitorEnter/Exit not implemented");
-	    case opc_multianewarray: {
-		Class clazz;
-		try {
-		    clazz = Class.forName((String) instr.objData);
-		} catch (ClassNotFoundException ex) {
-		    throw new InterpreterException
-			("Class "+ex.getMessage()+" not found");
+		default:
+		    throw new AssertError("Invalid opcode "+opcode);
 		}
-		int dimension = instr.intData;
-		int[] dims = new int[dimension];
-		for (int i=dimension - 1; i >= 0; i--)
-		    dims[i-1] = stack[--stacktop].intValue();
-		stack[stacktop++].setObject(Array.newInstance(clazz, dims));
-		break;
-	    }
-	    default:
-		throw new ClassFormatException("Invalid opcode "+opcode);
+	    } catch (InvocationTargetException ex) {
+		Handler[] handlers = code.getExceptionHandlers();
+		Throwable obj = ex.getTargetException();
+		for (int i=0; i< handlers.length; i++) {
+		    if (handlers[i].start.addr <= pc.addr
+			&& handlers[i].end.addr >= pc.addr
+			&& (handlers[i].type == null
+			    || env.instanceOf(obj, handlers[i].type))) {
+			stacktop = 0;
+			stack[stacktop++].setObject(obj);
+			pc = handlers[i].catcher;
+			continue big_loop;
+		    }
+		}
+		throw ex;
 	    }
 	}
-	} catch(RuntimeException ex) {
-	    ex.printStackTrace();
-	    throw new InterpreterException("Caught RuntimeException: "
-					   + ex.toString());
-	}
     }
 }