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	/*
	* Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package java.lang.invoke;

	import jdk.internal.org.objectweb.asm.ClassWriter;
	import jdk.internal.org.objectweb.asm.Label;
	import jdk.internal.org.objectweb.asm.MethodVisitor;
	import jdk.internal.org.objectweb.asm.Opcodes;
	import jdk.internal.org.objectweb.asm.Type;
	import sun.invoke.util.VerifyAccess;
	import sun.invoke.util.VerifyType;
	import sun.invoke.util.Wrapper;
	import sun.reflect.misc.ReflectUtil;

	import java.io.File;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.lang.reflect.Modifier;
	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.HashMap;
	import java.util.stream.Stream;

	import static java.lang.invoke.LambdaForm.BasicType;
	import static java.lang.invoke.LambdaForm.BasicType.*;
	import static java.lang.invoke.LambdaForm.*;
	import static java.lang.invoke.MethodHandleNatives.Constants.*;
	import static java.lang.invoke.MethodHandleStatics.*;

	/**
	* Code generation backend for LambdaForm.
	* <p>
	* @author John Rose, JSR 292 EG
	*/
	class InvokerBytecodeGenerator {
	/** Define class names for convenience. */
	private static final String MH = "java/lang/invoke/MethodHandle";
	private static final String MHI = "java/lang/invoke/MethodHandleImpl";
	private static final String LF = "java/lang/invoke/LambdaForm";
	private static final String LFN = "java/lang/invoke/LambdaForm$Name";
	private static final String CLS = "java/lang/Class";
	private static final String OBJ = "java/lang/Object";
	private static final String OBJARY = "[Ljava/lang/Object;";

	private static final String LOOP_CLAUSES = MHI + "$LoopClauses";
	private static final String MHARY2 = "[[L" + MH + ";";

	private static final String LF_SIG = "L" + LF + ";";
	private static final String LFN_SIG = "L" + LFN + ";";
	private static final String LL_SIG = "(L" + OBJ + ";)L" + OBJ + ";";
	private static final String LLV_SIG = "(L" + OBJ + ";L" + OBJ + ";)V";
	private static final String CLASS_PREFIX = LF + "$";
	private static final String SOURCE_PREFIX = "LambdaForm$";

	/** Name of its super class*/
	static final String INVOKER_SUPER_NAME = OBJ;

	/** Name of new class */
	private final String className;

	private final LambdaForm lambdaForm;
	private final String invokerName;
	private final MethodType invokerType;

	/** Info about local variables in compiled lambda form */
	private int[] localsMap; // index
	private Class<?>[] localClasses; // type

	/** ASM bytecode generation. */
	private ClassWriter cw;
	private MethodVisitor mv;

	/** Single element internal class name lookup cache. */
	private Class<?> lastClass;
	private String lastInternalName;

	private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory();
	private static final Class<?> HOST_CLASS = LambdaForm.class;

	/** Main constructor; other constructors delegate to this one. */
	private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize,
	String className, String invokerName, MethodType invokerType) {
	int p = invokerName.indexOf('.');
	if (p > -1) {
	className = invokerName.substring(0, p);
	invokerName = invokerName.substring(p + 1);
	}
	if (DUMP_CLASS_FILES) {
	className = makeDumpableClassName(className);
	}
	this.className = className;
	this.lambdaForm = lambdaForm;
	this.invokerName = invokerName;
	this.invokerType = invokerType;
	this.localsMap = new int[localsMapSize+1]; // last entry of localsMap is count of allocated local slots
	this.localClasses = new Class<?>[localsMapSize+1];
	}

	/** For generating LambdaForm interpreter entry points. */
	private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) {
	this(null, invokerType.parameterCount(),
	className, invokerName, invokerType);
	// Create an array to map name indexes to locals indexes.
	for (int i = 0; i < localsMap.length; i++) {
	localsMap[i] = invokerType.parameterSlotCount() - invokerType.parameterSlotDepth(i);
	}
	}

	/** For generating customized code for a single LambdaForm. */
	private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) {
	this(className, form.lambdaName(), form, invokerType);
	}

	/** For generating customized code for a single LambdaForm. */
	InvokerBytecodeGenerator(String className, String invokerName,
	LambdaForm form, MethodType invokerType) {
	this(form, form.names.length,
	className, invokerName, invokerType);
	// Create an array to map name indexes to locals indexes.
	Name[] names = form.names;
	for (int i = 0, index = 0; i < localsMap.length; i++) {
	localsMap[i] = index;
	if (i < names.length) {
	BasicType type = names[i].type();
	index += type.basicTypeSlots();
	}
	}
	}

	/** instance counters for dumped classes */
	private static final HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS;
	/** debugging flag for saving generated class files */
	private static final File DUMP_CLASS_FILES_DIR;

	static {
	if (DUMP_CLASS_FILES) {
	DUMP_CLASS_FILES_COUNTERS = new HashMap<>();
	try {
	File dumpDir = new File("DUMP_CLASS_FILES");
	if (!dumpDir.exists()) {
	dumpDir.mkdirs();
	}
	DUMP_CLASS_FILES_DIR = dumpDir;
	System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/...");
	} catch (Exception e) {
	throw newInternalError(e);
	}
	} else {
	DUMP_CLASS_FILES_COUNTERS = null;
	DUMP_CLASS_FILES_DIR = null;
	}
	}

	private void maybeDump(final byte[] classFile) {
	if (DUMP_CLASS_FILES) {
	maybeDump(CLASS_PREFIX + className, classFile);
	}
	}

	// Also used from BoundMethodHandle
	static void maybeDump(final String className, final byte[] classFile) {
	if (DUMP_CLASS_FILES) {
	java.security.AccessController.doPrivileged(
	new java.security.PrivilegedAction<>() {
	public Void run() {
	try {
	String dumpName = className.replace('.','/');
	File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class");
	System.out.println("dump: " + dumpFile);
	dumpFile.getParentFile().mkdirs();
	FileOutputStream file = new FileOutputStream(dumpFile);
	file.write(classFile);
	file.close();
	return null;
	} catch (IOException ex) {
	throw newInternalError(ex);
	}
	}
	});
	}
	}

	private static String makeDumpableClassName(String className) {
	Integer ctr;
	synchronized (DUMP_CLASS_FILES_COUNTERS) {
	ctr = DUMP_CLASS_FILES_COUNTERS.get(className);
	if (ctr == null) ctr = 0;
	DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1);
	}
	String sfx = ctr.toString();
	while (sfx.length() < 3)
	sfx = "0"+sfx;
	className += sfx;
	return className;
	}

	class CpPatch {
	final int index;
	final Object value;
	CpPatch(int index, Object value) {
	this.index = index;
	this.value = value;
	}
	public String toString() {
	return "CpPatch/index="+index+",value="+value;
	}
	}

	private final ArrayList<CpPatch> cpPatches = new ArrayList<>();

	private int cph = 0; // for counting constant placeholders

	String constantPlaceholder(Object arg) {
	String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++;
	if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + debugString(arg) + ">>";
	// TODO check if arg is already in the constant pool
	// insert placeholder in CP and remember the patch
	int index = cw.newConst((Object) cpPlaceholder);
	cpPatches.add(new CpPatch(index, arg));
	return cpPlaceholder;
	}

	Object[] cpPatches(byte[] classFile) {
	int size = getConstantPoolSize(classFile);
	Object[] res = new Object[size];
	for (CpPatch p : cpPatches) {
	if (p.index >= size)
	throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20)));
	res[p.index] = p.value;
	}
	return res;
	}

	private static String debugString(Object arg) {
	if (arg instanceof MethodHandle) {
	MethodHandle mh = (MethodHandle) arg;
	MemberName member = mh.internalMemberName();
	if (member != null)
	return member.toString();
	return mh.debugString();
	}
	return arg.toString();
	}

	/**
	* Extract the number of constant pool entries from a given class file.
	*
	* @param classFile the bytes of the class file in question.
	* @return the number of entries in the constant pool.
	*/
	private static int getConstantPoolSize(byte[] classFile) {
	// The first few bytes:
	// u4 magic;
	// u2 minor_version;
	// u2 major_version;
	// u2 constant_pool_count;
	return ((classFile[8] & 0xFF) << 8) \| (classFile[9] & 0xFF);
	}

	/**
	* Extract the MemberName of a newly-defined method.
	*/
	private MemberName loadMethod(byte[] classFile) {
	Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile));
	return resolveInvokerMember(invokerClass, invokerName, invokerType);
	}

	/**
	* Define a given class as anonymous class in the runtime system.
	*/
	private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) {
	Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches);
	UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain.
	return invokerClass;
	}

	private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) {
	MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic);
	try {
	member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class);
	} catch (ReflectiveOperationException e) {
	throw newInternalError(e);
	}
	return member;
	}

	/**
	* Set up class file generation.
	*/
	private ClassWriter classFilePrologue() {
	final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
	cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
	cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER,
	CLASS_PREFIX + className, null, INVOKER_SUPER_NAME, null);
	cw.visitSource(SOURCE_PREFIX + className, null);
	return cw;
	}

	private void methodPrologue() {
	String invokerDesc = invokerType.toMethodDescriptorString();
	mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null);
	}

	/**
	* Tear down class file generation.
	*/
	private void methodEpilogue() {
	mv.visitMaxs(0, 0);
	mv.visitEnd();
	}

	/*
	* Low-level emit helpers.
	*/
	private void emitConst(Object con) {
	if (con == null) {
	mv.visitInsn(Opcodes.ACONST_NULL);
	return;
	}
	if (con instanceof Integer) {
	emitIconstInsn((int) con);
	return;
	}
	if (con instanceof Byte) {
	emitIconstInsn((byte)con);
	return;
	}
	if (con instanceof Short) {
	emitIconstInsn((short)con);
	return;
	}
	if (con instanceof Character) {
	emitIconstInsn((char)con);
	return;
	}
	if (con instanceof Long) {
	long x = (long) con;
	short sx = (short)x;
	if (x == sx) {
	if (sx >= 0 && sx <= 1) {
	mv.visitInsn(Opcodes.LCONST_0 + (int) sx);
	} else {
	emitIconstInsn((int) x);
	mv.visitInsn(Opcodes.I2L);
	}
	return;
	}
	}
	if (con instanceof Float) {
	float x = (float) con;
	short sx = (short)x;
	if (x == sx) {
	if (sx >= 0 && sx <= 2) {
	mv.visitInsn(Opcodes.FCONST_0 + (int) sx);
	} else {
	emitIconstInsn((int) x);
	mv.visitInsn(Opcodes.I2F);
	}
	return;
	}
	}
	if (con instanceof Double) {
	double x = (double) con;
	short sx = (short)x;
	if (x == sx) {
	if (sx >= 0 && sx <= 1) {
	mv.visitInsn(Opcodes.DCONST_0 + (int) sx);
	} else {
	emitIconstInsn((int) x);
	mv.visitInsn(Opcodes.I2D);
	}
	return;
	}
	}
	if (con instanceof Boolean) {
	emitIconstInsn((boolean) con ? 1 : 0);
	return;
	}
	// fall through:
	mv.visitLdcInsn(con);
	}

	private void emitIconstInsn(final int cst) {
	if (cst >= -1 && cst <= 5) {
	mv.visitInsn(Opcodes.ICONST_0 + cst);
	} else if (cst >= Byte.MIN_VALUE && cst <= Byte.MAX_VALUE) {
	mv.visitIntInsn(Opcodes.BIPUSH, cst);
	} else if (cst >= Short.MIN_VALUE && cst <= Short.MAX_VALUE) {
	mv.visitIntInsn(Opcodes.SIPUSH, cst);
	} else {
	mv.visitLdcInsn(cst);
	}
	}

	/*
	* NOTE: These load/store methods use the localsMap to find the correct index!
	*/
	private void emitLoadInsn(BasicType type, int index) {
	int opcode = loadInsnOpcode(type);
	mv.visitVarInsn(opcode, localsMap[index]);
	}

	private int loadInsnOpcode(BasicType type) throws InternalError {
	switch (type) {
	case I_TYPE: return Opcodes.ILOAD;
	case J_TYPE: return Opcodes.LLOAD;
	case F_TYPE: return Opcodes.FLOAD;
	case D_TYPE: return Opcodes.DLOAD;
	case L_TYPE: return Opcodes.ALOAD;
	default:
	throw new InternalError("unknown type: " + type);
	}
	}
	private void emitAloadInsn(int index) {
	emitLoadInsn(L_TYPE, index);
	}

	private void emitStoreInsn(BasicType type, int index) {
	int opcode = storeInsnOpcode(type);
	mv.visitVarInsn(opcode, localsMap[index]);
	}

	private int storeInsnOpcode(BasicType type) throws InternalError {
	switch (type) {
	case I_TYPE: return Opcodes.ISTORE;
	case J_TYPE: return Opcodes.LSTORE;
	case F_TYPE: return Opcodes.FSTORE;
	case D_TYPE: return Opcodes.DSTORE;
	case L_TYPE: return Opcodes.ASTORE;
	default:
	throw new InternalError("unknown type: " + type);
	}
	}
	private void emitAstoreInsn(int index) {
	emitStoreInsn(L_TYPE, index);
	}

	private byte arrayTypeCode(Wrapper elementType) {
	switch (elementType) {
	case BOOLEAN: return Opcodes.T_BOOLEAN;
	case BYTE: return Opcodes.T_BYTE;
	case CHAR: return Opcodes.T_CHAR;
	case SHORT: return Opcodes.T_SHORT;
	case INT: return Opcodes.T_INT;
	case LONG: return Opcodes.T_LONG;
	case FLOAT: return Opcodes.T_FLOAT;
	case DOUBLE: return Opcodes.T_DOUBLE;
	case OBJECT: return 0; // in place of Opcodes.T_OBJECT
	default: throw new InternalError();
	}
	}

	private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError {
	assert(aaop == Opcodes.AASTORE \|\| aaop == Opcodes.AALOAD);
	int xas;
	switch (tcode) {
	case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break;
	case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break;
	case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break;
	case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break;
	case Opcodes.T_INT: xas = Opcodes.IASTORE; break;
	case Opcodes.T_LONG: xas = Opcodes.LASTORE; break;
	case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break;
	case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break;
	case 0: xas = Opcodes.AASTORE; break;
	default: throw new InternalError();
	}
	return xas - Opcodes.AASTORE + aaop;
	}

	/**
	* Emit a boxing call.
	*
	* @param wrapper primitive type class to box.
	*/
	private void emitBoxing(Wrapper wrapper) {
	String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
	String name = "valueOf";
	String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";";
	mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false);
	}

	/**
	* Emit an unboxing call (plus preceding checkcast).
	*
	* @param wrapper wrapper type class to unbox.
	*/
	private void emitUnboxing(Wrapper wrapper) {
	String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
	String name = wrapper.primitiveSimpleName() + "Value";
	String desc = "()" + wrapper.basicTypeChar();
	emitReferenceCast(wrapper.wrapperType(), null);
	mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false);
	}

	/**
	* Emit an implicit conversion for an argument which must be of the given pclass.
	* This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface.
	*
	* @param ptype type of value present on stack
	* @param pclass type of value required on stack
	* @param arg compile-time representation of value on stack (Node, constant) or null if none
	*/
	private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) {
	assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller
	if (pclass == ptype.basicTypeClass() && ptype != L_TYPE)
	return; // nothing to do
	switch (ptype) {
	case L_TYPE:
	if (VerifyType.isNullConversion(Object.class, pclass, false)) {
	if (PROFILE_LEVEL > 0)
	emitReferenceCast(Object.class, arg);
	return;
	}
	emitReferenceCast(pclass, arg);
	return;
	case I_TYPE:
	if (!VerifyType.isNullConversion(int.class, pclass, false))
	emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass));
	return;
	}
	throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass);
	}

	/** Update localClasses type map. Return true if the information is already present. */
	private boolean assertStaticType(Class<?> cls, Name n) {
	int local = n.index();
	Class<?> aclass = localClasses[local];
	if (aclass != null && (aclass == cls \|\| cls.isAssignableFrom(aclass))) {
	return true; // type info is already present
	} else if (aclass == null \|\| aclass.isAssignableFrom(cls)) {
	localClasses[local] = cls; // type info can be improved
	}
	return false;
	}

	private void emitReferenceCast(Class<?> cls, Object arg) {
	Name writeBack = null; // local to write back result
	if (arg instanceof Name) {
	Name n = (Name) arg;
	if (lambdaForm.useCount(n) > 1) {
	// This guy gets used more than once.
	writeBack = n;
	if (assertStaticType(cls, n)) {
	return; // this cast was already performed
	}
	}
	}
	if (isStaticallyNameable(cls)) {
	String sig = getInternalName(cls);
	mv.visitTypeInsn(Opcodes.CHECKCAST, sig);
	} else {
	mv.visitLdcInsn(constantPlaceholder(cls));
	mv.visitTypeInsn(Opcodes.CHECKCAST, CLS);
	mv.visitInsn(Opcodes.SWAP);
	mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, CLS, "cast", LL_SIG, false);
	if (Object[].class.isAssignableFrom(cls))
	mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY);
	else if (PROFILE_LEVEL > 0)
	mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ);
	}
	if (writeBack != null) {
	mv.visitInsn(Opcodes.DUP);
	emitAstoreInsn(writeBack.index());
	}
	}

	/**
	* Emits an actual return instruction conforming to the given return type.
	*/
	private void emitReturnInsn(BasicType type) {
	int opcode;
	switch (type) {
	case I_TYPE: opcode = Opcodes.IRETURN; break;
	case J_TYPE: opcode = Opcodes.LRETURN; break;
	case F_TYPE: opcode = Opcodes.FRETURN; break;
	case D_TYPE: opcode = Opcodes.DRETURN; break;
	case L_TYPE: opcode = Opcodes.ARETURN; break;
	case V_TYPE: opcode = Opcodes.RETURN; break;
	default:
	throw new InternalError("unknown return type: " + type);
	}
	mv.visitInsn(opcode);
	}

	private String getInternalName(Class<?> c) {
	if (c == Object.class) return OBJ;
	else if (c == Object[].class) return OBJARY;
	else if (c == Class.class) return CLS;
	else if (c == MethodHandle.class) return MH;
	assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName();

	if (c == lastClass) {
	return lastInternalName;
	}
	lastClass = c;
	return lastInternalName = c.getName().replace('.', '/');
	}

	private static MemberName resolveFrom(String name, MethodType type, Class<?> holder) {
	MemberName member = new MemberName(holder, name, type, REF_invokeStatic);
	MemberName resolvedMember = MemberName.getFactory().resolveOrNull(REF_invokeStatic, member, holder);
	if (TRACE_RESOLVE) {
	System.out.println("[LF_RESOLVE] " + holder.getName() + " " + name + " " +
	shortenSignature(basicTypeSignature(type)) + (resolvedMember != null ? " (success)" : " (fail)") );
	}
	return resolvedMember;
	}

	private static MemberName lookupPregenerated(LambdaForm form, MethodType invokerType) {
	if (form.customized != null) {
	// No pre-generated version for customized LF
	return null;
	}
	String name = form.kind.methodName;
	switch (form.kind) {
	case BOUND_REINVOKER: {
	name = name + "_" + BoundMethodHandle.speciesDataFor(form).key();
	return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class);
	}
	case DELEGATE: return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class);
	case ZERO: // fall-through
	case IDENTITY: {
	name = name + "_" + form.returnType().basicTypeChar();
	return resolveFrom(name, invokerType, LambdaForm.Holder.class);
	}
	case EXACT_INVOKER: // fall-through
	case EXACT_LINKER: // fall-through
	case LINK_TO_CALL_SITE: // fall-through
	case LINK_TO_TARGET_METHOD: // fall-through
	case GENERIC_INVOKER: // fall-through
	case GENERIC_LINKER: return resolveFrom(name, invokerType.basicType(), Invokers.Holder.class);
	case GET_OBJECT: // fall-through
	case GET_BOOLEAN: // fall-through
	case GET_BYTE: // fall-through
	case GET_CHAR: // fall-through
	case GET_SHORT: // fall-through
	case GET_INT: // fall-through
	case GET_LONG: // fall-through
	case GET_FLOAT: // fall-through
	case GET_DOUBLE: // fall-through
	case PUT_OBJECT: // fall-through
	case PUT_BOOLEAN: // fall-through
	case PUT_BYTE: // fall-through
	case PUT_CHAR: // fall-through
	case PUT_SHORT: // fall-through
	case PUT_INT: // fall-through
	case PUT_LONG: // fall-through
	case PUT_FLOAT: // fall-through
	case PUT_DOUBLE: // fall-through
	case DIRECT_NEW_INVOKE_SPECIAL: // fall-through
	case DIRECT_INVOKE_INTERFACE: // fall-through
	case DIRECT_INVOKE_SPECIAL: // fall-through
	case DIRECT_INVOKE_SPECIAL_IFC: // fall-through
	case DIRECT_INVOKE_STATIC: // fall-through
	case DIRECT_INVOKE_STATIC_INIT: // fall-through
	case DIRECT_INVOKE_VIRTUAL: return resolveFrom(name, invokerType, DirectMethodHandle.Holder.class);
	}
	return null;
	}

	/**
	* Generate customized bytecode for a given LambdaForm.
	*/
	static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) {
	MemberName pregenerated = lookupPregenerated(form, invokerType);
	if (pregenerated != null) return pregenerated; // pre-generated bytecode

	InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
	return g.loadMethod(g.generateCustomizedCodeBytes());
	}

	/** Generates code to check that actual receiver and LambdaForm matches */
	private boolean checkActualReceiver() {
	// Expects MethodHandle on the stack and actual receiver MethodHandle in slot #0
	mv.visitInsn(Opcodes.DUP);
	mv.visitVarInsn(Opcodes.ALOAD, localsMap[0]);
	mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "assertSame", LLV_SIG, false);
	return true;
	}

	static String className(String cn) {
	assert checkClassName(cn): "Class not found: " + cn;
	return cn;
	}

	static boolean checkClassName(String cn) {
	Type tp = Type.getType(cn);
	// additional sanity so only valid "L;" descriptors work
	if (tp.getSort() != Type.OBJECT) {
	return false;
	}
	try {
	Class<?> c = Class.forName(tp.getClassName(), false, null);
	return true;
	} catch (ClassNotFoundException e) {
	return false;
	}
	}

	static final String LF_HIDDEN_SIG = className("Ljava/lang/invoke/LambdaForm$Hidden;");
	static final String LF_COMPILED_SIG = className("Ljava/lang/invoke/LambdaForm$Compiled;");
	static final String FORCEINLINE_SIG = className("Ljdk/internal/vm/annotation/ForceInline;");
	static final String DONTINLINE_SIG = className("Ljdk/internal/vm/annotation/DontInline;");
	static final String INJECTEDPROFILE_SIG = className("Ljava/lang/invoke/InjectedProfile;");

	/**
	* Generate an invoker method for the passed {@link LambdaForm}.
	*/
	private byte[] generateCustomizedCodeBytes() {
	classFilePrologue();
	addMethod();
	bogusMethod(lambdaForm);

	final byte[] classFile = toByteArray();
	maybeDump(classFile);
	return classFile;
	}

	void setClassWriter(ClassWriter cw) {
	this.cw = cw;
	}

	void addMethod() {
	methodPrologue();

	// Suppress this method in backtraces displayed to the user.
	mv.visitAnnotation(LF_HIDDEN_SIG, true);

	// Mark this method as a compiled LambdaForm
	mv.visitAnnotation(LF_COMPILED_SIG, true);

	if (lambdaForm.forceInline) {
	// Force inlining of this invoker method.
	mv.visitAnnotation(FORCEINLINE_SIG, true);
	} else {
	mv.visitAnnotation(DONTINLINE_SIG, true);
	}

	constantPlaceholder(lambdaForm); // keep LambdaForm instance & its compiled form lifetime tightly coupled.

	if (lambdaForm.customized != null) {
	// Since LambdaForm is customized for a particular MethodHandle, it's safe to substitute
	// receiver MethodHandle (at slot #0) with an embedded constant and use it instead.
	// It enables more efficient code generation in some situations, since embedded constants
	// are compile-time constants for JIT compiler.
	mv.visitLdcInsn(constantPlaceholder(lambdaForm.customized));
	mv.visitTypeInsn(Opcodes.CHECKCAST, MH);
	assert(checkActualReceiver()); // expects MethodHandle on top of the stack
	mv.visitVarInsn(Opcodes.ASTORE, localsMap[0]);
	}

	// iterate over the form's names, generating bytecode instructions for each
	// start iterating at the first name following the arguments
	Name onStack = null;
	for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) {
	Name name = lambdaForm.names[i];

	emitStoreResult(onStack);
	onStack = name; // unless otherwise modified below
	MethodHandleImpl.Intrinsic intr = name.function.intrinsicName();
	switch (intr) {
	case SELECT_ALTERNATIVE:
	assert lambdaForm.isSelectAlternative(i);
	if (PROFILE_GWT) {
	assert(name.arguments[0] instanceof Name &&
	((Name)name.arguments[0]).refersTo(MethodHandleImpl.class, "profileBoolean"));
	mv.visitAnnotation(INJECTEDPROFILE_SIG, true);
	}
	onStack = emitSelectAlternative(name, lambdaForm.names[i+1]);
	i++; // skip MH.invokeBasic of the selectAlternative result
	continue;
	case GUARD_WITH_CATCH:
	assert lambdaForm.isGuardWithCatch(i);
	onStack = emitGuardWithCatch(i);
	i += 2; // jump to the end of GWC idiom
	continue;
	case TRY_FINALLY:
	assert lambdaForm.isTryFinally(i);
	onStack = emitTryFinally(i);
	i += 2; // jump to the end of the TF idiom
	continue;
	case LOOP:
	assert lambdaForm.isLoop(i);
	onStack = emitLoop(i);
	i += 2; // jump to the end of the LOOP idiom
	continue;
	case NEW_ARRAY:
	Class<?> rtype = name.function.methodType().returnType();
	if (isStaticallyNameable(rtype)) {
	emitNewArray(name);
	continue;
	}
	break;
	case ARRAY_LOAD:
	emitArrayLoad(name);
	continue;
	case ARRAY_STORE:
	emitArrayStore(name);
	continue;
	case ARRAY_LENGTH:
	emitArrayLength(name);
	continue;
	case IDENTITY:
	assert(name.arguments.length == 1);
	emitPushArguments(name, 0);
	continue;
	case ZERO:
	assert(name.arguments.length == 0);
	emitConst(name.type.basicTypeWrapper().zero());
	continue;
	case NONE:
	// no intrinsic associated
	break;
	default:
	throw newInternalError("Unknown intrinsic: "+intr);
	}

	MemberName member = name.function.member();
	if (isStaticallyInvocable(member)) {
	emitStaticInvoke(member, name);
	} else {
	emitInvoke(name);
	}
	}

	// return statement
	emitReturn(onStack);

	methodEpilogue();
	}

	/*
	* @throws BytecodeGenerationException if something goes wrong when
	* generating the byte code
	*/
	private byte[] toByteArray() {
	try {
	return cw.toByteArray();
	} catch (RuntimeException e) {
	throw new BytecodeGenerationException(e);
	}
	}

	@SuppressWarnings("serial")
	static final class BytecodeGenerationException extends RuntimeException {
	BytecodeGenerationException(Exception cause) {
	super(cause);
	}
	}

	void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); }
	void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); }
	void emitArrayLength(Name name) { emitArrayOp(name, Opcodes.ARRAYLENGTH); }

	void emitArrayOp(Name name, int arrayOpcode) {
	assert arrayOpcode == Opcodes.AALOAD \|\| arrayOpcode == Opcodes.AASTORE \|\| arrayOpcode == Opcodes.ARRAYLENGTH;
	Class<?> elementType = name.function.methodType().parameterType(0).getComponentType();
	assert elementType != null;
	emitPushArguments(name, 0);
	if (arrayOpcode != Opcodes.ARRAYLENGTH && elementType.isPrimitive()) {
	Wrapper w = Wrapper.forPrimitiveType(elementType);
	arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode);
	}
	mv.visitInsn(arrayOpcode);
	}

	/**
	* Emit an invoke for the given name.
	*/
	void emitInvoke(Name name) {
	assert(!name.isLinkerMethodInvoke()); // should use the static path for these
	if (true) {
	// push receiver
	MethodHandle target = name.function.resolvedHandle();
	assert(target != null) : name.exprString();
	mv.visitLdcInsn(constantPlaceholder(target));
	emitReferenceCast(MethodHandle.class, target);
	} else {
	// load receiver
	emitAloadInsn(0);
	emitReferenceCast(MethodHandle.class, null);
	mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG);
	mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG);
	// TODO more to come
	}

	// push arguments
	emitPushArguments(name, 0);

	// invocation
	MethodType type = name.function.methodType();
	mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
	}

	private static Class<?>[] STATICALLY_INVOCABLE_PACKAGES = {
	// Sample classes from each package we are willing to bind to statically:
	java.lang.Object.class,
	java.util.Arrays.class,
	jdk.internal.misc.Unsafe.class
	//MethodHandle.class already covered
	};

	static boolean isStaticallyInvocable(NamedFunction ... functions) {
	for (NamedFunction nf : functions) {
	if (!isStaticallyInvocable(nf.member())) {
	return false;
	}
	}
	return true;
	}

	static boolean isStaticallyInvocable(Name name) {
	return isStaticallyInvocable(name.function.member());
	}

	static boolean isStaticallyInvocable(MemberName member) {
	if (member == null) return false;
	if (member.isConstructor()) return false;
	Class<?> cls = member.getDeclaringClass();
	// Fast-path non-private members declared by MethodHandles, which is a common
	// case
	if (MethodHandle.class.isAssignableFrom(cls) && !member.isPrivate()) {
	assert(isStaticallyInvocableType(member.getMethodOrFieldType()));
	return true;
	}
	if (cls.isArray() \|\| cls.isPrimitive())
	return false; // FIXME
	if (cls.isAnonymousClass() \|\| cls.isLocalClass())
	return false; // inner class of some sort
	if (cls.getClassLoader() != MethodHandle.class.getClassLoader())
	return false; // not on BCP
	if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
	return false;
	if (!isStaticallyInvocableType(member.getMethodOrFieldType()))
	return false;
	if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls))
	return true; // in java.lang.invoke package
	if (member.isPublic() && isStaticallyNameable(cls))
	return true;
	return false;
	}

	private static boolean isStaticallyInvocableType(MethodType mtype) {
	if (!isStaticallyNameable(mtype.returnType()))
	return false;
	for (Class<?> ptype : mtype.parameterArray())
	if (!isStaticallyNameable(ptype))
	return false;
	return true;
	}

	static boolean isStaticallyNameable(Class<?> cls) {
	if (cls == Object.class)
	return true;
	if (MethodHandle.class.isAssignableFrom(cls)) {
	assert(!ReflectUtil.isVMAnonymousClass(cls));
	return true;
	}
	while (cls.isArray())
	cls = cls.getComponentType();
	if (cls.isPrimitive())
	return true; // int[].class, for example
	if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
	return false;
	// could use VerifyAccess.isClassAccessible but the following is a safe approximation
	if (cls.getClassLoader() != Object.class.getClassLoader())
	return false;
	if (VerifyAccess.isSamePackage(MethodHandle.class, cls))
	return true;
	if (!Modifier.isPublic(cls.getModifiers()))
	return false;
	for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) {
	if (VerifyAccess.isSamePackage(pkgcls, cls))
	return true;
	}
	return false;
	}

	void emitStaticInvoke(Name name) {
	emitStaticInvoke(name.function.member(), name);
	}

	/**
	* Emit an invoke for the given name, using the MemberName directly.
	*/
	void emitStaticInvoke(MemberName member, Name name) {
	assert(member.equals(name.function.member()));
	Class<?> defc = member.getDeclaringClass();
	String cname = getInternalName(defc);
	String mname = member.getName();
	String mtype;
	byte refKind = member.getReferenceKind();
	if (refKind == REF_invokeSpecial) {
	// in order to pass the verifier, we need to convert this to invokevirtual in all cases
	assert(member.canBeStaticallyBound()) : member;
	refKind = REF_invokeVirtual;
	}

	assert(!(member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual));

	// push arguments
	emitPushArguments(name, 0);

	// invocation
	if (member.isMethod()) {
	mtype = member.getMethodType().toMethodDescriptorString();
	mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype,
	member.getDeclaringClass().isInterface());
	} else {
	mtype = MethodType.toFieldDescriptorString(member.getFieldType());
	mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype);
	}
	// Issue a type assertion for the result, so we can avoid casts later.
	if (name.type == L_TYPE) {
	Class<?> rtype = member.getInvocationType().returnType();
	assert(!rtype.isPrimitive());
	if (rtype != Object.class && !rtype.isInterface()) {
	assertStaticType(rtype, name);
	}
	}
	}

	void emitNewArray(Name name) throws InternalError {
	Class<?> rtype = name.function.methodType().returnType();
	if (name.arguments.length == 0) {
	// The array will be a constant.
	Object emptyArray;
	try {
	emptyArray = name.function.resolvedHandle().invoke();
	} catch (Throwable ex) {
	throw uncaughtException(ex);
	}
	assert(java.lang.reflect.Array.getLength(emptyArray) == 0);
	assert(emptyArray.getClass() == rtype); // exact typing
	mv.visitLdcInsn(constantPlaceholder(emptyArray));
	emitReferenceCast(rtype, emptyArray);
	return;
	}
	Class<?> arrayElementType = rtype.getComponentType();
	assert(arrayElementType != null);
	emitIconstInsn(name.arguments.length);
	int xas = Opcodes.AASTORE;
	if (!arrayElementType.isPrimitive()) {
	mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType));
	} else {
	byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType));
	xas = arrayInsnOpcode(tc, xas);
	mv.visitIntInsn(Opcodes.NEWARRAY, tc);
	}
	// store arguments
	for (int i = 0; i < name.arguments.length; i++) {
	mv.visitInsn(Opcodes.DUP);
	emitIconstInsn(i);
	emitPushArgument(name, i);
	mv.visitInsn(xas);
	}
	// the array is left on the stack
	assertStaticType(rtype, name);
	}
	int refKindOpcode(byte refKind) {
	switch (refKind) {
	case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL;
	case REF_invokeStatic: return Opcodes.INVOKESTATIC;
	case REF_invokeSpecial: return Opcodes.INVOKESPECIAL;
	case REF_invokeInterface: return Opcodes.INVOKEINTERFACE;
	case REF_getField: return Opcodes.GETFIELD;
	case REF_putField: return Opcodes.PUTFIELD;
	case REF_getStatic: return Opcodes.GETSTATIC;
	case REF_putStatic: return Opcodes.PUTSTATIC;
	}
	throw new InternalError("refKind="+refKind);
	}

	/**
	* Emit bytecode for the selectAlternative idiom.
	*
	* The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest):
	* <blockquote><pre>{@code
	* Lambda(a0:L,a1:I)=>{
	* t2:I=foo.test(a1:I);
	* t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int));
	* t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I}
	* }</pre></blockquote>
	*/
	private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) {
	assert isStaticallyInvocable(invokeBasicName);

	Name receiver = (Name) invokeBasicName.arguments[0];

	Label L_fallback = new Label();
	Label L_done = new Label();

	// load test result
	emitPushArgument(selectAlternativeName, 0);

	// if_icmpne L_fallback
	mv.visitJumpInsn(Opcodes.IFEQ, L_fallback);

	// invoke selectAlternativeName.arguments[1]
	Class<?>[] preForkClasses = localClasses.clone();
	emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative
	emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
	emitStaticInvoke(invokeBasicName);

	// goto L_done
	mv.visitJumpInsn(Opcodes.GOTO, L_done);

	// L_fallback:
	mv.visitLabel(L_fallback);

	// invoke selectAlternativeName.arguments[2]
	System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
	emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative
	emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
	emitStaticInvoke(invokeBasicName);

	// L_done:
	mv.visitLabel(L_done);
	// for now do not bother to merge typestate; just reset to the dominator state
	System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);

	return invokeBasicName; // return what's on stack
	}

	/**
	* Emit bytecode for the guardWithCatch idiom.
	*
	* The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch):
	* <blockquote><pre>{@code
	* guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{
	* t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L);
	* t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L);
	* t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I}
	* }</pre></blockquote>
	*
	* It is compiled into bytecode equivalent of the following code:
	* <blockquote><pre>{@code
	* try {
	* return a1.invokeBasic(a6, a7);
	* } catch (Throwable e) {
	* if (!a2.isInstance(e)) throw e;
	* return a3.invokeBasic(ex, a6, a7);
	* }}
	*/
	private Name emitGuardWithCatch(int pos) {
	Name args = lambdaForm.names[pos];
	Name invoker = lambdaForm.names[pos+1];
	Name result = lambdaForm.names[pos+2];

	Label L_startBlock = new Label();
	Label L_endBlock = new Label();
	Label L_handler = new Label();
	Label L_done = new Label();

	Class<?> returnType = result.function.resolvedHandle().type().returnType();
	MethodType type = args.function.resolvedHandle().type()
	.dropParameterTypes(0,1)
	.changeReturnType(returnType);

	mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable");

	// Normal case
	mv.visitLabel(L_startBlock);
	// load target
	emitPushArgument(invoker, 0);
	emitPushArguments(args, 1); // skip 1st argument: method handle
	mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
	mv.visitLabel(L_endBlock);
	mv.visitJumpInsn(Opcodes.GOTO, L_done);

	// Exceptional case
	mv.visitLabel(L_handler);

	// Check exception's type
	mv.visitInsn(Opcodes.DUP);
	// load exception class
	emitPushArgument(invoker, 1);
	mv.visitInsn(Opcodes.SWAP);
	mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false);
	Label L_rethrow = new Label();
	mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow);

	// Invoke catcher
	// load catcher
	emitPushArgument(invoker, 2);
	mv.visitInsn(Opcodes.SWAP);
	emitPushArguments(args, 1); // skip 1st argument: method handle
	MethodType catcherType = type.insertParameterTypes(0, Throwable.class);
	mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false);
	mv.visitJumpInsn(Opcodes.GOTO, L_done);

	mv.visitLabel(L_rethrow);
	mv.visitInsn(Opcodes.ATHROW);

	mv.visitLabel(L_done);

	return result;
	}

	/**
	* Emit bytecode for the tryFinally idiom.
	* <p>
	* The pattern looks like (Cf. MethodHandleImpl.makeTryFinally):
	* <blockquote><pre>{@code
	* // a0: BMH
	* // a1: target, a2: cleanup
	* // a3: box, a4: unbox
	* // a5 (and following): arguments
	* tryFinally=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L)=>{
	* t6:L=MethodHandle.invokeBasic(a3:L,a5:L); // box the arguments into an Object[]
	* t7:L=MethodHandleImpl.tryFinally(a1:L,a2:L,t6:L); // call the tryFinally executor
	* t8:L=MethodHandle.invokeBasic(a4:L,t7:L);t8:L} // unbox the result; return the result
	* }</pre></blockquote>
	* <p>
	* It is compiled into bytecode equivalent to the following code:
	* <blockquote><pre>{@code
	* Throwable t;
	* Object r;
	* try {
	* r = a1.invokeBasic(a5);
	* } catch (Throwable thrown) {
	* t = thrown;
	* throw t;
	* } finally {
	* r = a2.invokeBasic(t, r, a5);
	* }
	* return r;
	* }</pre></blockquote>
	* <p>
	* Specifically, the bytecode will have the following form (the stack effects are given for the beginnings of
	* blocks, and for the situations after executing the given instruction - the code will have a slightly different
	* shape if the return type is {@code void}):
	* <blockquote><pre>{@code
	* TRY: (--)
	* load target (-- target)
	* load args (-- args... target)
	* INVOKEVIRTUAL MethodHandle.invokeBasic (depends)
	* FINALLY_NORMAL: (-- r)
	* load cleanup (-- cleanup r)
	* SWAP (-- r cleanup)
	* ACONST_NULL (-- t r cleanup)
	* SWAP (-- r t cleanup)
	* load args (-- args... r t cleanup)
	* INVOKEVIRTUAL MethodHandle.invokeBasic (-- r)
	* GOTO DONE
	* CATCH: (-- t)
	* DUP (-- t t)
	* FINALLY_EXCEPTIONAL: (-- t t)
	* load cleanup (-- cleanup t t)
	* SWAP (-- t cleanup t)
	* load default for r (-- r t cleanup t)
	* load args (-- args... r t cleanup t)
	* INVOKEVIRTUAL MethodHandle.invokeBasic (-- r t)
	* POP (-- t)
	* ATHROW
	* DONE: (-- r)
	* }</pre></blockquote>
	*/
	private Name emitTryFinally(int pos) {
	Name args = lambdaForm.names[pos];
	Name invoker = lambdaForm.names[pos+1];
	Name result = lambdaForm.names[pos+2];

	Label lFrom = new Label();
	Label lTo = new Label();
	Label lCatch = new Label();
	Label lDone = new Label();

	Class<?> returnType = result.function.resolvedHandle().type().returnType();
	boolean isNonVoid = returnType != void.class;
	MethodType type = args.function.resolvedHandle().type()
	.dropParameterTypes(0,1)
	.changeReturnType(returnType);
	MethodType cleanupType = type.insertParameterTypes(0, Throwable.class);
	if (isNonVoid) {
	cleanupType = cleanupType.insertParameterTypes(1, returnType);
	}
	String cleanupDesc = cleanupType.basicType().toMethodDescriptorString();

	// exception handler table
	mv.visitTryCatchBlock(lFrom, lTo, lCatch, "java/lang/Throwable");

	// TRY:
	mv.visitLabel(lFrom);
	emitPushArgument(invoker, 0); // load target
	emitPushArguments(args, 1); // load args (skip 0: method handle)
	mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
	mv.visitLabel(lTo);

	// FINALLY_NORMAL:
	emitPushArgument(invoker, 1); // load cleanup
	if (isNonVoid) {
	mv.visitInsn(Opcodes.SWAP);
	}
	mv.visitInsn(Opcodes.ACONST_NULL);
	if (isNonVoid) {
	mv.visitInsn(Opcodes.SWAP);
	}
	emitPushArguments(args, 1); // load args (skip 0: method handle)
	mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false);
	mv.visitJumpInsn(Opcodes.GOTO, lDone);

	// CATCH:
	mv.visitLabel(lCatch);
	mv.visitInsn(Opcodes.DUP);

	// FINALLY_EXCEPTIONAL:
	emitPushArgument(invoker, 1); // load cleanup
	mv.visitInsn(Opcodes.SWAP);
	if (isNonVoid) {
	emitZero(BasicType.basicType(returnType)); // load default for result
	}
	emitPushArguments(args, 1); // load args (skip 0: method handle)
	mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false);
	if (isNonVoid) {
	mv.visitInsn(Opcodes.POP);
	}
	mv.visitInsn(Opcodes.ATHROW);

	// DONE:
	mv.visitLabel(lDone);

	return result;
	}

	/**
	* Emit bytecode for the loop idiom.
	* <p>
	* The pattern looks like (Cf. MethodHandleImpl.loop):
	* <blockquote><pre>{@code
	* // a0: BMH
	* // a1: LoopClauses (containing an array of arrays: inits, steps, preds, finis)
	* // a2: box, a3: unbox
	* // a4 (and following): arguments
	* loop=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L)=>{
	* t5:L=MethodHandle.invokeBasic(a2:L,a4:L); // box the arguments into an Object[]
	* t6:L=MethodHandleImpl.loop(bt:L,a1:L,t5:L); // call the loop executor (with supplied types in bt)
	* t7:L=MethodHandle.invokeBasic(a3:L,t6:L);t7:L} // unbox the result; return the result
	* }</pre></blockquote>
	* <p>
	* It is compiled into bytecode equivalent to the code seen in {@link MethodHandleImpl#loop(BasicType[],
	* MethodHandleImpl.LoopClauses, Object...)}, with the difference that no arrays
	* will be used for local state storage. Instead, the local state will be mapped to actual stack slots.
	* <p>
	* Bytecode generation applies an unrolling scheme to enable better bytecode generation regarding local state type
	* handling. The generated bytecode will have the following form ({@code void} types are ignored for convenience).
	* Assume there are {@code C} clauses in the loop.
	* <blockquote><pre>{@code
	* PREINIT: ALOAD_1
	* CHECKCAST LoopClauses
	* GETFIELD LoopClauses.clauses
	* ASTORE clauseDataIndex // place the clauses 2-dimensional array on the stack
	* INIT: (INIT_SEQ for clause 1)
	* ...
	* (INIT_SEQ for clause C)
	* LOOP: (LOOP_SEQ for clause 1)
	* ...
	* (LOOP_SEQ for clause C)
	* GOTO LOOP
	* DONE: ...
	* }</pre></blockquote>
	* <p>
	* The {@code INIT_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has
	* the following shape. Assume slot {@code vx} is used to hold the state for clause {@code x}.
	* <blockquote><pre>{@code
	* INIT_SEQ_x: ALOAD clauseDataIndex
	* ICONST_0
	* AALOAD // load the inits array
	* ICONST x
	* AALOAD // load the init handle for clause x
	* load args
	* INVOKEVIRTUAL MethodHandle.invokeBasic
	* store vx
	* }</pre></blockquote>
	* <p>
	* The {@code LOOP_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has
	* the following shape. Again, assume slot {@code vx} is used to hold the state for clause {@code x}.
	* <blockquote><pre>{@code
	* LOOP_SEQ_x: ALOAD clauseDataIndex
	* ICONST_1
	* AALOAD // load the steps array
	* ICONST x
	* AALOAD // load the step handle for clause x
	* load locals
	* load args
	* INVOKEVIRTUAL MethodHandle.invokeBasic
	* store vx
	* ALOAD clauseDataIndex
	* ICONST_2
	* AALOAD // load the preds array
	* ICONST x
	* AALOAD // load the pred handle for clause x
	* load locals
	* load args
	* INVOKEVIRTUAL MethodHandle.invokeBasic
	* IFNE LOOP_SEQ_x+1 // predicate returned false -> jump to next clause
	* ALOAD clauseDataIndex
	* ICONST_3
	* AALOAD // load the finis array
	* ICONST x
	* AALOAD // load the fini handle for clause x
	* load locals
	* load args
	* INVOKEVIRTUAL MethodHandle.invokeBasic
	* GOTO DONE // jump beyond end of clauses to return from loop
	* }</pre></blockquote>
	*/
	private Name emitLoop(int pos) {
	Name args = lambdaForm.names[pos];
	Name invoker = lambdaForm.names[pos+1];
	Name result = lambdaForm.names[pos+2];

	// extract clause and loop-local state types
	// find the type info in the loop invocation
	BasicType[] loopClauseTypes = (BasicType[]) invoker.arguments[0];
	Class<?>[] loopLocalStateTypes = Stream.of(loopClauseTypes).
	filter(bt -> bt != BasicType.V_TYPE).map(BasicType::basicTypeClass).toArray(Class<?>[]::new);
	Class<?>[] localTypes = new Class<?>[loopLocalStateTypes.length + 1];
	localTypes[0] = MethodHandleImpl.LoopClauses.class;
	System.arraycopy(loopLocalStateTypes, 0, localTypes, 1, loopLocalStateTypes.length);

	final int clauseDataIndex = extendLocalsMap(localTypes);
	final int firstLoopStateIndex = clauseDataIndex + 1;

	Class<?> returnType = result.function.resolvedHandle().type().returnType();
	MethodType loopType = args.function.resolvedHandle().type()
	.dropParameterTypes(0,1)
	.changeReturnType(returnType);
	MethodType loopHandleType = loopType.insertParameterTypes(0, loopLocalStateTypes);
	MethodType predType = loopHandleType.changeReturnType(boolean.class);
	MethodType finiType = loopHandleType;

	final int nClauses = loopClauseTypes.length;

	// indices to invoker arguments to load method handle arrays
	final int inits = 1;
	final int steps = 2;
	final int preds = 3;
	final int finis = 4;

	Label lLoop = new Label();
	Label lDone = new Label();
	Label lNext;

	// PREINIT:
	emitPushArgument(MethodHandleImpl.LoopClauses.class, invoker.arguments[1]);
	mv.visitFieldInsn(Opcodes.GETFIELD, LOOP_CLAUSES, "clauses", MHARY2);
	emitAstoreInsn(clauseDataIndex);

	// INIT:
	for (int c = 0, state = 0; c < nClauses; ++c) {
	MethodType cInitType = loopType.changeReturnType(loopClauseTypes[c].basicTypeClass());
	emitLoopHandleInvoke(invoker, inits, c, args, false, cInitType, loopLocalStateTypes, clauseDataIndex,
	firstLoopStateIndex);
	if (cInitType.returnType() != void.class) {
	emitStoreInsn(BasicType.basicType(cInitType.returnType()), firstLoopStateIndex + state);
	++state;
	}
	}

	// LOOP:
	mv.visitLabel(lLoop);

	for (int c = 0, state = 0; c < nClauses; ++c) {
	lNext = new Label();

	MethodType stepType = loopHandleType.changeReturnType(loopClauseTypes[c].basicTypeClass());
	boolean isVoid = stepType.returnType() == void.class;

	// invoke loop step
	emitLoopHandleInvoke(invoker, steps, c, args, true, stepType, loopLocalStateTypes, clauseDataIndex,
	firstLoopStateIndex);
	if (!isVoid) {
	emitStoreInsn(BasicType.basicType(stepType.returnType()), firstLoopStateIndex + state);
	++state;
	}

	// invoke loop predicate
	emitLoopHandleInvoke(invoker, preds, c, args, true, predType, loopLocalStateTypes, clauseDataIndex,
	firstLoopStateIndex);
	mv.visitJumpInsn(Opcodes.IFNE, lNext);

	// invoke fini
	emitLoopHandleInvoke(invoker, finis, c, args, true, finiType, loopLocalStateTypes, clauseDataIndex,
	firstLoopStateIndex);
	mv.visitJumpInsn(Opcodes.GOTO, lDone);

	// this is the beginning of the next loop clause
	mv.visitLabel(lNext);
	}

	mv.visitJumpInsn(Opcodes.GOTO, lLoop);

	// DONE:
	mv.visitLabel(lDone);

	return result;
	}

	private int extendLocalsMap(Class<?>[] types) {
	int firstSlot = localsMap.length - 1;
	localsMap = Arrays.copyOf(localsMap, localsMap.length + types.length);
	localClasses = Arrays.copyOf(localClasses, localClasses.length + types.length);
	System.arraycopy(types, 0, localClasses, firstSlot, types.length);
	int index = localsMap[firstSlot - 1] + 1;
	int lastSlots = 0;
	for (int i = 0; i < types.length; ++i) {
	localsMap[firstSlot + i] = index;
	lastSlots = BasicType.basicType(localClasses[firstSlot + i]).basicTypeSlots();
	index += lastSlots;
	}
	localsMap[localsMap.length - 1] = index - lastSlots;
	return firstSlot;
	}

	private void emitLoopHandleInvoke(Name holder, int handles, int clause, Name args, boolean pushLocalState,
	MethodType type, Class<?>[] loopLocalStateTypes, int clauseDataSlot,
	int firstLoopStateSlot) {
	// load handle for clause
	emitPushClauseArray(clauseDataSlot, handles);
	emitIconstInsn(clause);
	mv.visitInsn(Opcodes.AALOAD);
	// load loop state (preceding the other arguments)
	if (pushLocalState) {
	for (int s = 0; s < loopLocalStateTypes.length; ++s) {
	emitLoadInsn(BasicType.basicType(loopLocalStateTypes[s]), firstLoopStateSlot + s);
	}
	}
	// load loop args (skip 0: method handle)
	emitPushArguments(args, 1);
	mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.toMethodDescriptorString(), false);
	}

	private void emitPushClauseArray(int clauseDataSlot, int which) {
	emitAloadInsn(clauseDataSlot);
	emitIconstInsn(which - 1);
	mv.visitInsn(Opcodes.AALOAD);
	}

	private void emitZero(BasicType type) {
	switch (type) {
	case I_TYPE: mv.visitInsn(Opcodes.ICONST_0); break;
	case J_TYPE: mv.visitInsn(Opcodes.LCONST_0); break;
	case F_TYPE: mv.visitInsn(Opcodes.FCONST_0); break;
	case D_TYPE: mv.visitInsn(Opcodes.DCONST_0); break;
	case L_TYPE: mv.visitInsn(Opcodes.ACONST_NULL); break;
	default: throw new InternalError("unknown type: " + type);
	}
	}

	private void emitPushArguments(Name args, int start) {
	MethodType type = args.function.methodType();
	for (int i = start; i < args.arguments.length; i++) {
	emitPushArgument(type.parameterType(i), args.arguments[i]);
	}
	}

	private void emitPushArgument(Name name, int paramIndex) {
	Object arg = name.arguments[paramIndex];
	Class<?> ptype = name.function.methodType().parameterType(paramIndex);
	emitPushArgument(ptype, arg);
	}

	private void emitPushArgument(Class<?> ptype, Object arg) {
	BasicType bptype = basicType(ptype);
	if (arg instanceof Name) {
	Name n = (Name) arg;
	emitLoadInsn(n.type, n.index());
	emitImplicitConversion(n.type, ptype, n);
	} else if ((arg == null \|\| arg instanceof String) && bptype == L_TYPE) {
	emitConst(arg);
	} else {
	if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) {
	emitConst(arg);
	} else {
	mv.visitLdcInsn(constantPlaceholder(arg));
	emitImplicitConversion(L_TYPE, ptype, arg);
	}
	}
	}

	/**
	* Store the name to its local, if necessary.
	*/
	private void emitStoreResult(Name name) {
	if (name != null && name.type != V_TYPE) {
	// non-void: actually assign
	emitStoreInsn(name.type, name.index());
	}
	}

	/**
	* Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type.
	*/
	private void emitReturn(Name onStack) {
	// return statement
	Class<?> rclass = invokerType.returnType();
	BasicType rtype = lambdaForm.returnType();
	assert(rtype == basicType(rclass)); // must agree
	if (rtype == V_TYPE) {
	// void
	mv.visitInsn(Opcodes.RETURN);
	// it doesn't matter what rclass is; the JVM will discard any value
	} else {
	LambdaForm.Name rn = lambdaForm.names[lambdaForm.result];

	// put return value on the stack if it is not already there
	if (rn != onStack) {
	emitLoadInsn(rtype, lambdaForm.result);
	}

	emitImplicitConversion(rtype, rclass, rn);

	// generate actual return statement
	emitReturnInsn(rtype);
	}
	}

	/**
	* Emit a type conversion bytecode casting from "from" to "to".
	*/
	private void emitPrimCast(Wrapper from, Wrapper to) {
	// Here's how.
	// - indicates forbidden
	// <-> indicates implicit
	// to ----> boolean byte short char int long float double
	// from boolean <-> - - - - - - -
	// byte - <-> i2s i2c <-> i2l i2f i2d
	// short - i2b <-> i2c <-> i2l i2f i2d
	// char - i2b i2s <-> <-> i2l i2f i2d
	// int - i2b i2s i2c <-> i2l i2f i2d
	// long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d
	// float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d
	// double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <->
	if (from == to) {
	// no cast required, should be dead code anyway
	return;
	}
	if (from.isSubwordOrInt()) {
	// cast from {byte,short,char,int} to anything
	emitI2X(to);
	} else {
	// cast from {long,float,double} to anything
	if (to.isSubwordOrInt()) {
	// cast to {byte,short,char,int}
	emitX2I(from);
	if (to.bitWidth() < 32) {
	// targets other than int require another conversion
	emitI2X(to);
	}
	} else {
	// cast to {long,float,double} - this is verbose
	boolean error = false;
	switch (from) {
	case LONG:
	switch (to) {
	case FLOAT: mv.visitInsn(Opcodes.L2F); break;
	case DOUBLE: mv.visitInsn(Opcodes.L2D); break;
	default: error = true; break;
	}
	break;
	case FLOAT:
	switch (to) {
	case LONG : mv.visitInsn(Opcodes.F2L); break;
	case DOUBLE: mv.visitInsn(Opcodes.F2D); break;
	default: error = true; break;
	}
	break;
	case DOUBLE:
	switch (to) {
	case LONG : mv.visitInsn(Opcodes.D2L); break;
	case FLOAT: mv.visitInsn(Opcodes.D2F); break;
	default: error = true; break;
	}
	break;
	default:
	error = true;
	break;
	}
	if (error) {
	throw new IllegalStateException("unhandled prim cast: " + from + "2" + to);
	}
	}
	}
	}

	private void emitI2X(Wrapper type) {
	switch (type) {
	case BYTE: mv.visitInsn(Opcodes.I2B); break;
	case SHORT: mv.visitInsn(Opcodes.I2S); break;
	case CHAR: mv.visitInsn(Opcodes.I2C); break;
	case INT: /* naught */ break;
	case LONG: mv.visitInsn(Opcodes.I2L); break;
	case FLOAT: mv.visitInsn(Opcodes.I2F); break;
	case DOUBLE: mv.visitInsn(Opcodes.I2D); break;
	case BOOLEAN:
	// For compatibility with ValueConversions and explicitCastArguments:
	mv.visitInsn(Opcodes.ICONST_1);
	mv.visitInsn(Opcodes.IAND);
	break;
	default: throw new InternalError("unknown type: " + type);
	}
	}

	private void emitX2I(Wrapper type) {
	switch (type) {
	case LONG: mv.visitInsn(Opcodes.L2I); break;
	case FLOAT: mv.visitInsn(Opcodes.F2I); break;
	case DOUBLE: mv.visitInsn(Opcodes.D2I); break;
	default: throw new InternalError("unknown type: " + type);
	}
	}

	/**
	* Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments.
	*/
	static MemberName generateLambdaFormInterpreterEntryPoint(MethodType mt) {
	assert(isValidSignature(basicTypeSignature(mt)));
	String name = "interpret_"+basicTypeChar(mt.returnType());
	MethodType type = mt; // includes leading argument
	type = type.changeParameterType(0, MethodHandle.class);
	InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type);
	return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes());
	}

	private byte[] generateLambdaFormInterpreterEntryPointBytes() {
	classFilePrologue();
	methodPrologue();

	// Suppress this method in backtraces displayed to the user.
	mv.visitAnnotation(LF_HIDDEN_SIG, true);

	// Don't inline the interpreter entry.
	mv.visitAnnotation(DONTINLINE_SIG, true);

	// create parameter array
	emitIconstInsn(invokerType.parameterCount());
	mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object");

	// fill parameter array
	for (int i = 0; i < invokerType.parameterCount(); i++) {
	Class<?> ptype = invokerType.parameterType(i);
	mv.visitInsn(Opcodes.DUP);
	emitIconstInsn(i);
	emitLoadInsn(basicType(ptype), i);
	// box if primitive type
	if (ptype.isPrimitive()) {
	emitBoxing(Wrapper.forPrimitiveType(ptype));
	}
	mv.visitInsn(Opcodes.AASTORE);
	}
	// invoke
	emitAloadInsn(0);
	mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;");
	mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable
	mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false);

	// maybe unbox
	Class<?> rtype = invokerType.returnType();
	if (rtype.isPrimitive() && rtype != void.class) {
	emitUnboxing(Wrapper.forPrimitiveType(rtype));
	}

	// return statement
	emitReturnInsn(basicType(rtype));

	methodEpilogue();
	bogusMethod(invokerType);

	final byte[] classFile = cw.toByteArray();
	maybeDump(classFile);
	return classFile;
	}

	/**
	* Generate bytecode for a NamedFunction invoker.
	*/
	static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) {
	MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE;
	String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType()));
	InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType);
	return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm));
	}

	private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) {
	MethodType dstType = typeForm.erasedType();
	classFilePrologue();
	methodPrologue();

	// Suppress this method in backtraces displayed to the user.
	mv.visitAnnotation(LF_HIDDEN_SIG, true);

	// Force inlining of this invoker method.
	mv.visitAnnotation(FORCEINLINE_SIG, true);

	// Load receiver
	emitAloadInsn(0);

	// Load arguments from array
	for (int i = 0; i < dstType.parameterCount(); i++) {
	emitAloadInsn(1);
	emitIconstInsn(i);
	mv.visitInsn(Opcodes.AALOAD);

	// Maybe unbox
	Class<?> dptype = dstType.parameterType(i);
	if (dptype.isPrimitive()) {
	Wrapper dstWrapper = Wrapper.forBasicType(dptype);
	Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int
	emitUnboxing(srcWrapper);
	emitPrimCast(srcWrapper, dstWrapper);
	}
	}

	// Invoke
	String targetDesc = dstType.basicType().toMethodDescriptorString();
	mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false);

	// Box primitive types
	Class<?> rtype = dstType.returnType();
	if (rtype != void.class && rtype.isPrimitive()) {
	Wrapper srcWrapper = Wrapper.forBasicType(rtype);
	Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int
	// boolean casts not allowed
	emitPrimCast(srcWrapper, dstWrapper);
	emitBoxing(dstWrapper);
	}

	// If the return type is void we return a null reference.
	if (rtype == void.class) {
	mv.visitInsn(Opcodes.ACONST_NULL);
	}
	emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value.

	methodEpilogue();
	bogusMethod(dstType);

	final byte[] classFile = cw.toByteArray();
	maybeDump(classFile);
	return classFile;
	}

	/**
	* Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool
	* for debugging purposes.
	*/
	private void bogusMethod(Object os) {
	if (DUMP_CLASS_FILES) {
	mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null);
	mv.visitLdcInsn(os.toString());
	mv.visitInsn(Opcodes.POP);
	mv.visitInsn(Opcodes.RETURN);
	mv.visitMaxs(0, 0);
	mv.visitEnd();
	}
	}
	}

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