diff -r 000000000000 -r c880a8a8803b rt/emul/compact/src/main/java/java/lang/invoke/LambdaForm.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rt/emul/compact/src/main/java/java/lang/invoke/LambdaForm.java	Sat Aug 09 11:11:13 2014 +0200
@@ -0,0 +1,1646 @@
+/*
+ * Copyright (c) 2011, 2013, 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 java.lang.annotation.*;
+import java.lang.reflect.Method;
+import java.util.Map;
+import java.util.List;
+import java.util.Arrays;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.concurrent.ConcurrentHashMap;
+import sun.invoke.util.Wrapper;
+import static java.lang.invoke.MethodHandleStatics.*;
+import static java.lang.invoke.MethodHandleNatives.Constants.*;
+import java.lang.reflect.Field;
+import java.util.Objects;
+
+/**
+ * The symbolic, non-executable form of a method handle's invocation semantics.
+ * It consists of a series of names.
+ * The first N (N=arity) names are parameters,
+ * while any remaining names are temporary values.
+ * Each temporary specifies the application of a function to some arguments.
+ * The functions are method handles, while the arguments are mixes of
+ * constant values and local names.
+ * The result of the lambda is defined as one of the names, often the last one.
+ * <p>
+ * Here is an approximate grammar:
+ * <blockquote><pre>{@code
+ * LambdaForm = "(" ArgName* ")=>{" TempName* Result "}"
+ * ArgName = "a" N ":" T
+ * TempName = "t" N ":" T "=" Function "(" Argument* ");"
+ * Function = ConstantValue
+ * Argument = NameRef | ConstantValue
+ * Result = NameRef | "void"
+ * NameRef = "a" N | "t" N
+ * N = (any whole number)
+ * T = "L" | "I" | "J" | "F" | "D" | "V"
+ * }</pre></blockquote>
+ * Names are numbered consecutively from left to right starting at zero.
+ * (The letters are merely a taste of syntax sugar.)
+ * Thus, the first temporary (if any) is always numbered N (where N=arity).
+ * Every occurrence of a name reference in an argument list must refer to
+ * a name previously defined within the same lambda.
+ * A lambda has a void result if and only if its result index is -1.
+ * If a temporary has the type "V", it cannot be the subject of a NameRef,
+ * even though possesses a number.
+ * Note that all reference types are erased to "L", which stands for {@code Object}.
+ * All subword types (boolean, byte, short, char) are erased to "I" which is {@code int}.
+ * The other types stand for the usual primitive types.
+ * <p>
+ * Function invocation closely follows the static rules of the Java verifier.
+ * Arguments and return values must exactly match when their "Name" types are
+ * considered.
+ * Conversions are allowed only if they do not change the erased type.
+ * <ul>
+ * <li>L = Object: casts are used freely to convert into and out of reference types
+ * <li>I = int: subword types are forcibly narrowed when passed as arguments (see {@code explicitCastArguments})
+ * <li>J = long: no implicit conversions
+ * <li>F = float: no implicit conversions
+ * <li>D = double: no implicit conversions
+ * <li>V = void: a function result may be void if and only if its Name is of type "V"
+ * </ul>
+ * Although implicit conversions are not allowed, explicit ones can easily be
+ * encoded by using temporary expressions which call type-transformed identity functions.
+ * <p>
+ * Examples:
+ * <blockquote><pre>{@code
+ * (a0:J)=>{ a0 }
+ *     == identity(long)
+ * (a0:I)=>{ t1:V = System.out#println(a0); void }
+ *     == System.out#println(int)
+ * (a0:L)=>{ t1:V = System.out#println(a0); a0 }
+ *     == identity, with printing side-effect
+ * (a0:L, a1:L)=>{ t2:L = BoundMethodHandle#argument(a0);
+ *                 t3:L = BoundMethodHandle#target(a0);
+ *                 t4:L = MethodHandle#invoke(t3, t2, a1); t4 }
+ *     == general invoker for unary insertArgument combination
+ * (a0:L, a1:L)=>{ t2:L = FilterMethodHandle#filter(a0);
+ *                 t3:L = MethodHandle#invoke(t2, a1);
+ *                 t4:L = FilterMethodHandle#target(a0);
+ *                 t5:L = MethodHandle#invoke(t4, t3); t5 }
+ *     == general invoker for unary filterArgument combination
+ * (a0:L, a1:L)=>{ ...(same as previous example)...
+ *                 t5:L = MethodHandle#invoke(t4, t3, a1); t5 }
+ *     == general invoker for unary/unary foldArgument combination
+ * (a0:L, a1:I)=>{ t2:I = identity(long).asType((int)->long)(a1); t2 }
+ *     == invoker for identity method handle which performs i2l
+ * (a0:L, a1:L)=>{ t2:L = BoundMethodHandle#argument(a0);
+ *                 t3:L = Class#cast(t2,a1); t3 }
+ *     == invoker for identity method handle which performs cast
+ * }</pre></blockquote>
+ * <p>
+ * @author John Rose, JSR 292 EG
+ */
+class LambdaForm {
+    final int arity;
+    final int result;
+    @Stable final Name[] names;
+    final String debugName;
+    MemberName vmentry;   // low-level behavior, or null if not yet prepared
+    private boolean isCompiled;
+
+    // Caches for common structural transforms:
+    LambdaForm[] bindCache;
+
+    public static final int VOID_RESULT = -1, LAST_RESULT = -2;
+
+    LambdaForm(String debugName,
+               int arity, Name[] names, int result) {
+        assert(namesOK(arity, names));
+        this.arity = arity;
+        this.result = fixResult(result, names);
+        this.names = names.clone();
+        this.debugName = debugName;
+        normalize();
+    }
+
+    LambdaForm(String debugName,
+               int arity, Name[] names) {
+        this(debugName,
+             arity, names, LAST_RESULT);
+    }
+
+    LambdaForm(String debugName,
+               Name[] formals, Name[] temps, Name result) {
+        this(debugName,
+             formals.length, buildNames(formals, temps, result), LAST_RESULT);
+    }
+
+    private static Name[] buildNames(Name[] formals, Name[] temps, Name result) {
+        int arity = formals.length;
+        int length = arity + temps.length + (result == null ? 0 : 1);
+        Name[] names = Arrays.copyOf(formals, length);
+        System.arraycopy(temps, 0, names, arity, temps.length);
+        if (result != null)
+            names[length - 1] = result;
+        return names;
+    }
+
+    private LambdaForm(String sig) {
+        // Make a blank lambda form, which returns a constant zero or null.
+        // It is used as a template for managing the invocation of similar forms that are non-empty.
+        // Called only from getPreparedForm.
+        assert(isValidSignature(sig));
+        this.arity = signatureArity(sig);
+        this.result = (signatureReturn(sig) == 'V' ? -1 : arity);
+        this.names = buildEmptyNames(arity, sig);
+        this.debugName = "LF.zero";
+        assert(nameRefsAreLegal());
+        assert(isEmpty());
+        assert(sig.equals(basicTypeSignature()));
+    }
+
+    private static Name[] buildEmptyNames(int arity, String basicTypeSignature) {
+        assert(isValidSignature(basicTypeSignature));
+        int resultPos = arity + 1;  // skip '_'
+        if (arity < 0 || basicTypeSignature.length() != resultPos+1)
+            throw new IllegalArgumentException("bad arity for "+basicTypeSignature);
+        int numRes = (basicTypeSignature.charAt(resultPos) == 'V' ? 0 : 1);
+        Name[] names = arguments(numRes, basicTypeSignature.substring(0, arity));
+        for (int i = 0; i < numRes; i++) {
+            names[arity + i] = constantZero(arity + i, basicTypeSignature.charAt(resultPos + i));
+        }
+        return names;
+    }
+
+    private static int fixResult(int result, Name[] names) {
+        if (result >= 0) {
+            if (names[result].type == 'V')
+                return -1;
+        } else if (result == LAST_RESULT) {
+            return names.length - 1;
+        }
+        return result;
+    }
+
+    private static boolean namesOK(int arity, Name[] names) {
+        for (int i = 0; i < names.length; i++) {
+            Name n = names[i];
+            assert(n != null) : "n is null";
+            if (i < arity)
+                assert( n.isParam()) : n + " is not param at " + i;
+            else
+                assert(!n.isParam()) : n + " is param at " + i;
+        }
+        return true;
+    }
+
+    /** Renumber and/or replace params so that they are interned and canonically numbered. */
+    private void normalize() {
+        Name[] oldNames = null;
+        int changesStart = 0;
+        for (int i = 0; i < names.length; i++) {
+            Name n = names[i];
+            if (!n.initIndex(i)) {
+                if (oldNames == null) {
+                    oldNames = names.clone();
+                    changesStart = i;
+                }
+                names[i] = n.cloneWithIndex(i);
+            }
+        }
+        if (oldNames != null) {
+            int startFixing = arity;
+            if (startFixing <= changesStart)
+                startFixing = changesStart+1;
+            for (int i = startFixing; i < names.length; i++) {
+                Name fixed = names[i].replaceNames(oldNames, names, changesStart, i);
+                names[i] = fixed.newIndex(i);
+            }
+        }
+        assert(nameRefsAreLegal());
+        int maxInterned = Math.min(arity, INTERNED_ARGUMENT_LIMIT);
+        boolean needIntern = false;
+        for (int i = 0; i < maxInterned; i++) {
+            Name n = names[i], n2 = internArgument(n);
+            if (n != n2) {
+                names[i] = n2;
+                needIntern = true;
+            }
+        }
+        if (needIntern) {
+            for (int i = arity; i < names.length; i++) {
+                names[i].internArguments();
+            }
+            assert(nameRefsAreLegal());
+        }
+    }
+
+    /**
+     * Check that all embedded Name references are localizable to this lambda,
+     * and are properly ordered after their corresponding definitions.
+     * <p>
+     * Note that a Name can be local to multiple lambdas, as long as
+     * it possesses the same index in each use site.
+     * This allows Name references to be freely reused to construct
+     * fresh lambdas, without confusion.
+     */
+    private boolean nameRefsAreLegal() {
+        assert(arity >= 0 && arity <= names.length);
+        assert(result >= -1 && result < names.length);
+        // Do all names possess an index consistent with their local definition order?
+        for (int i = 0; i < arity; i++) {
+            Name n = names[i];
+            assert(n.index() == i) : Arrays.asList(n.index(), i);
+            assert(n.isParam());
+        }
+        // Also, do all local name references
+        for (int i = arity; i < names.length; i++) {
+            Name n = names[i];
+            assert(n.index() == i);
+            for (Object arg : n.arguments) {
+                if (arg instanceof Name) {
+                    Name n2 = (Name) arg;
+                    int i2 = n2.index;
+                    assert(0 <= i2 && i2 < names.length) : n.debugString() + ": 0 <= i2 && i2 < names.length: 0 <= " + i2 + " < " + names.length;
+                    assert(names[i2] == n2) : Arrays.asList("-1-", i, "-2-", n.debugString(), "-3-", i2, "-4-", n2.debugString(), "-5-", names[i2].debugString(), "-6-", this);
+                    assert(i2 < i);  // ref must come after def!
+                }
+            }
+        }
+        return true;
+    }
+
+    /** Invoke this form on the given arguments. */
+    // final Object invoke(Object... args) throws Throwable {
+    //     // NYI: fit this into the fast path?
+    //     return interpretWithArguments(args);
+    // }
+
+    /** Report the return type. */
+    char returnType() {
+        if (result < 0)  return 'V';
+        Name n = names[result];
+        return n.type;
+    }
+
+    /** Report the N-th argument type. */
+    char parameterType(int n) {
+        assert(n < arity);
+        return names[n].type;
+    }
+
+    /** Report the arity. */
+    int arity() {
+        return arity;
+    }
+
+    /** Return the method type corresponding to my basic type signature. */
+    MethodType methodType() {
+        return signatureType(basicTypeSignature());
+    }
+    /** Return ABC_Z, where the ABC are parameter type characters, and Z is the return type character. */
+    final String basicTypeSignature() {
+        StringBuilder buf = new StringBuilder(arity() + 3);
+        for (int i = 0, a = arity(); i < a; i++)
+            buf.append(parameterType(i));
+        return buf.append('_').append(returnType()).toString();
+    }
+    static int signatureArity(String sig) {
+        assert(isValidSignature(sig));
+        return sig.indexOf('_');
+    }
+    static char signatureReturn(String sig) {
+        return sig.charAt(signatureArity(sig)+1);
+    }
+    static boolean isValidSignature(String sig) {
+        int arity = sig.indexOf('_');
+        if (arity < 0)  return false;  // must be of the form *_*
+        int siglen = sig.length();
+        if (siglen != arity + 2)  return false;  // *_X
+        for (int i = 0; i < siglen; i++) {
+            if (i == arity)  continue;  // skip '_'
+            char c = sig.charAt(i);
+            if (c == 'V')
+                return (i == siglen - 1 && arity == siglen - 2);
+            if (ALL_TYPES.indexOf(c) < 0)  return false; // must be [LIJFD]
+        }
+        return true;  // [LIJFD]*_[LIJFDV]
+    }
+    static Class<?> typeClass(char t) {
+        switch (t) {
+        case 'I': return int.class;
+        case 'J': return long.class;
+        case 'F': return float.class;
+        case 'D': return double.class;
+        case 'L': return Object.class;
+        case 'V': return void.class;
+        default: assert false;
+        }
+        return null;
+    }
+    static MethodType signatureType(String sig) {
+        Class<?>[] ptypes = new Class<?>[signatureArity(sig)];
+        for (int i = 0; i < ptypes.length; i++)
+            ptypes[i] = typeClass(sig.charAt(i));
+        Class<?> rtype = typeClass(signatureReturn(sig));
+        return MethodType.methodType(rtype, ptypes);
+    }
+
+    /*
+     * Code generation issues:
+     *
+     * Compiled LFs should be reusable in general.
+     * The biggest issue is how to decide when to pull a name into
+     * the bytecode, versus loading a reified form from the MH data.
+     *
+     * For example, an asType wrapper may require execution of a cast
+     * after a call to a MH.  The target type of the cast can be placed
+     * as a constant in the LF itself.  This will force the cast type
+     * to be compiled into the bytecodes and native code for the MH.
+     * Or, the target type of the cast can be erased in the LF, and
+     * loaded from the MH data.  (Later on, if the MH as a whole is
+     * inlined, the data will flow into the inlined instance of the LF,
+     * as a constant, and the end result will be an optimal cast.)
+     *
+     * This erasure of cast types can be done with any use of
+     * reference types.  It can also be done with whole method
+     * handles.  Erasing a method handle might leave behind
+     * LF code that executes correctly for any MH of a given
+     * type, and load the required MH from the enclosing MH's data.
+     * Or, the erasure might even erase the expected MT.
+     *
+     * Also, for direct MHs, the MemberName of the target
+     * could be erased, and loaded from the containing direct MH.
+     * As a simple case, a LF for all int-valued non-static
+     * field getters would perform a cast on its input argument
+     * (to non-constant base type derived from the MemberName)
+     * and load an integer value from the input object
+     * (at a non-constant offset also derived from the MemberName).
+     * Such MN-erased LFs would be inlinable back to optimized
+     * code, whenever a constant enclosing DMH is available
+     * to supply a constant MN from its data.
+     *
+     * The main problem here is to keep LFs reasonably generic,
+     * while ensuring that hot spots will inline good instances.
+     * "Reasonably generic" means that we don't end up with
+     * repeated versions of bytecode or machine code that do
+     * not differ in their optimized form.  Repeated versions
+     * of machine would have the undesirable overheads of
+     * (a) redundant compilation work and (b) extra I$ pressure.
+     * To control repeated versions, we need to be ready to
+     * erase details from LFs and move them into MH data,
+     * whevener those details are not relevant to significant
+     * optimization.  "Significant" means optimization of
+     * code that is actually hot.
+     *
+     * Achieving this may require dynamic splitting of MHs, by replacing
+     * a generic LF with a more specialized one, on the same MH,
+     * if (a) the MH is frequently executed and (b) the MH cannot
+     * be inlined into a containing caller, such as an invokedynamic.
+     *
+     * Compiled LFs that are no longer used should be GC-able.
+     * If they contain non-BCP references, they should be properly
+     * interlinked with the class loader(s) that their embedded types
+     * depend on.  This probably means that reusable compiled LFs
+     * will be tabulated (indexed) on relevant class loaders,
+     * or else that the tables that cache them will have weak links.
+     */
+
+    /**
+     * Make this LF directly executable, as part of a MethodHandle.
+     * Invariant:  Every MH which is invoked must prepare its LF
+     * before invocation.
+     * (In principle, the JVM could do this very lazily,
+     * as a sort of pre-invocation linkage step.)
+     */
+    public void prepare() {
+        if (COMPILE_THRESHOLD == 0) {
+            compileToBytecode();
+        }
+        if (this.vmentry != null) {
+            // already prepared (e.g., a primitive DMH invoker form)
+            return;
+        }
+        LambdaForm prep = getPreparedForm(basicTypeSignature());
+        this.vmentry = prep.vmentry;
+        // TO DO: Maybe add invokeGeneric, invokeWithArguments
+    }
+
+    /** Generate optimizable bytecode for this form. */
+    MemberName compileToBytecode() {
+        MethodType invokerType = methodType();
+        assert(vmentry == null || vmentry.getMethodType().basicType().equals(invokerType));
+        if (vmentry != null && isCompiled) {
+            return vmentry;  // already compiled somehow
+        }
+        try {
+            vmentry = InvokerBytecodeGenerator.generateCustomizedCode(this, invokerType);
+            if (TRACE_INTERPRETER)
+                traceInterpreter("compileToBytecode", this);
+            isCompiled = true;
+            return vmentry;
+        } catch (Error | Exception ex) {
+            throw newInternalError("compileToBytecode", ex);
+        }
+    }
+
+    private static final ConcurrentHashMap<String,LambdaForm> PREPARED_FORMS;
+    static {
+        int   capacity   = 512;    // expect many distinct signatures over time
+        float loadFactor = 0.75f;  // normal default
+        int   writers    = 1;
+        PREPARED_FORMS = new ConcurrentHashMap<>(capacity, loadFactor, writers);
+    }
+
+    private static Map<String,LambdaForm> computeInitialPreparedForms() {
+        // Find all predefined invokers and associate them with canonical empty lambda forms.
+        HashMap<String,LambdaForm> forms = new HashMap<>();
+        for (MemberName m : MemberName.getFactory().getMethods(LambdaForm.class, false, null, null, null)) {
+            if (!m.isStatic() || !m.isPackage())  continue;
+            MethodType mt = m.getMethodType();
+            if (mt.parameterCount() > 0 &&
+                mt.parameterType(0) == MethodHandle.class &&
+                m.getName().startsWith("interpret_")) {
+                String sig = basicTypeSignature(mt);
+                assert(m.getName().equals("interpret" + sig.substring(sig.indexOf('_'))));
+                LambdaForm form = new LambdaForm(sig);
+                form.vmentry = m;
+                mt.form().setCachedLambdaForm(MethodTypeForm.LF_COUNTER, form);
+                // FIXME: get rid of PREPARED_FORMS; use MethodTypeForm cache only
+                forms.put(sig, form);
+            }
+        }
+        //System.out.println("computeInitialPreparedForms => "+forms);
+        return forms;
+    }
+
+    // Set this false to disable use of the interpret_L methods defined in this file.
+    private static final boolean USE_PREDEFINED_INTERPRET_METHODS = true;
+
+    // The following are predefined exact invokers.  The system must build
+    // a separate invoker for each distinct signature.
+    static Object interpret_L(MethodHandle mh) throws Throwable {
+        Object[] av = {mh};
+        String sig = null;
+        assert(argumentTypesMatch(sig = "L_L", av));
+        Object res = mh.form.interpretWithArguments(av);
+        assert(returnTypesMatch(sig, av, res));
+        return res;
+    }
+    static Object interpret_L(MethodHandle mh, Object x1) throws Throwable {
+        Object[] av = {mh, x1};
+        String sig = null;
+        assert(argumentTypesMatch(sig = "LL_L", av));
+        Object res = mh.form.interpretWithArguments(av);
+        assert(returnTypesMatch(sig, av, res));
+        return res;
+    }
+    static Object interpret_L(MethodHandle mh, Object x1, Object x2) throws Throwable {
+        Object[] av = {mh, x1, x2};
+        String sig = null;
+        assert(argumentTypesMatch(sig = "LLL_L", av));
+        Object res = mh.form.interpretWithArguments(av);
+        assert(returnTypesMatch(sig, av, res));
+        return res;
+    }
+    private static LambdaForm getPreparedForm(String sig) {
+        MethodType mtype = signatureType(sig);
+        //LambdaForm prep = PREPARED_FORMS.get(sig);
+        LambdaForm prep =  mtype.form().cachedLambdaForm(MethodTypeForm.LF_INTERPRET);
+        if (prep != null)  return prep;
+        assert(isValidSignature(sig));
+        prep = new LambdaForm(sig);
+        prep.vmentry = InvokerBytecodeGenerator.generateLambdaFormInterpreterEntryPoint(sig);
+        //LambdaForm prep2 = PREPARED_FORMS.putIfAbsent(sig.intern(), prep);
+        return mtype.form().setCachedLambdaForm(MethodTypeForm.LF_INTERPRET, prep);
+    }
+
+    // The next few routines are called only from assert expressions
+    // They verify that the built-in invokers process the correct raw data types.
+    private static boolean argumentTypesMatch(String sig, Object[] av) {
+        int arity = signatureArity(sig);
+        assert(av.length == arity) : "av.length == arity: av.length=" + av.length + ", arity=" + arity;
+        assert(av[0] instanceof MethodHandle) : "av[0] not instace of MethodHandle: " + av[0];
+        MethodHandle mh = (MethodHandle) av[0];
+        MethodType mt = mh.type();
+        assert(mt.parameterCount() == arity-1);
+        for (int i = 0; i < av.length; i++) {
+            Class<?> pt = (i == 0 ? MethodHandle.class : mt.parameterType(i-1));
+            assert(valueMatches(sig.charAt(i), pt, av[i]));
+        }
+        return true;
+    }
+    private static boolean valueMatches(char tc, Class<?> type, Object x) {
+        // The following line is needed because (...)void method handles can use non-void invokers
+        if (type == void.class)  tc = 'V';   // can drop any kind of value
+        assert tc == basicType(type) : tc + " == basicType(" + type + ")=" + basicType(type);
+        switch (tc) {
+        case 'I': assert checkInt(type, x)   : "checkInt(" + type + "," + x +")";   break;
+        case 'J': assert x instanceof Long   : "instanceof Long: " + x;             break;
+        case 'F': assert x instanceof Float  : "instanceof Float: " + x;            break;
+        case 'D': assert x instanceof Double : "instanceof Double: " + x;           break;
+        case 'L': assert checkRef(type, x)   : "checkRef(" + type + "," + x + ")";  break;
+        case 'V': break;  // allow anything here; will be dropped
+        default:  assert(false);
+        }
+        return true;
+    }
+    private static boolean returnTypesMatch(String sig, Object[] av, Object res) {
+        MethodHandle mh = (MethodHandle) av[0];
+        return valueMatches(signatureReturn(sig), mh.type().returnType(), res);
+    }
+    private static boolean checkInt(Class<?> type, Object x) {
+        assert(x instanceof Integer);
+        if (type == int.class)  return true;
+        Wrapper w = Wrapper.forBasicType(type);
+        assert(w.isSubwordOrInt());
+        Object x1 = Wrapper.INT.wrap(w.wrap(x));
+        return x.equals(x1);
+    }
+    private static boolean checkRef(Class<?> type, Object x) {
+        assert(!type.isPrimitive());
+        if (x == null)  return true;
+        if (type.isInterface())  return true;
+        return type.isInstance(x);
+    }
+
+    /** If the invocation count hits the threshold we spin bytecodes and call that subsequently. */
+    private static final int COMPILE_THRESHOLD;
+    static {
+        if (MethodHandleStatics.COMPILE_THRESHOLD != null)
+            COMPILE_THRESHOLD = MethodHandleStatics.COMPILE_THRESHOLD;
+        else
+            COMPILE_THRESHOLD = 30;  // default value
+    }
+    private int invocationCounter = 0;
+
+    @Hidden
+    @DontInline
+    /** Interpretively invoke this form on the given arguments. */
+    Object interpretWithArguments(Object... argumentValues) throws Throwable {
+        if (TRACE_INTERPRETER)
+            return interpretWithArgumentsTracing(argumentValues);
+        checkInvocationCounter();
+        assert(arityCheck(argumentValues));
+        Object[] values = Arrays.copyOf(argumentValues, names.length);
+        for (int i = argumentValues.length; i < values.length; i++) {
+            values[i] = interpretName(names[i], values);
+        }
+        return (result < 0) ? null : values[result];
+    }
+
+    @Hidden
+    @DontInline
+    /** Evaluate a single Name within this form, applying its function to its arguments. */
+    Object interpretName(Name name, Object[] values) throws Throwable {
+        if (TRACE_INTERPRETER)
+            traceInterpreter("| interpretName", name.debugString(), (Object[]) null);
+        Object[] arguments = Arrays.copyOf(name.arguments, name.arguments.length, Object[].class);
+        for (int i = 0; i < arguments.length; i++) {
+            Object a = arguments[i];
+            if (a instanceof Name) {
+                int i2 = ((Name)a).index();
+                assert(names[i2] == a);
+                a = values[i2];
+                arguments[i] = a;
+            }
+        }
+        return name.function.invokeWithArguments(arguments);
+    }
+
+    private void checkInvocationCounter() {
+        if (COMPILE_THRESHOLD != 0 &&
+            invocationCounter < COMPILE_THRESHOLD) {
+            invocationCounter++;  // benign race
+            if (invocationCounter >= COMPILE_THRESHOLD) {
+                // Replace vmentry with a bytecode version of this LF.
+                compileToBytecode();
+            }
+        }
+    }
+    Object interpretWithArgumentsTracing(Object... argumentValues) throws Throwable {
+        traceInterpreter("[ interpretWithArguments", this, argumentValues);
+        if (invocationCounter < COMPILE_THRESHOLD) {
+            int ctr = invocationCounter++;  // benign race
+            traceInterpreter("| invocationCounter", ctr);
+            if (invocationCounter >= COMPILE_THRESHOLD) {
+                compileToBytecode();
+            }
+        }
+        Object rval;
+        try {
+            assert(arityCheck(argumentValues));
+            Object[] values = Arrays.copyOf(argumentValues, names.length);
+            for (int i = argumentValues.length; i < values.length; i++) {
+                values[i] = interpretName(names[i], values);
+            }
+            rval = (result < 0) ? null : values[result];
+        } catch (Throwable ex) {
+            traceInterpreter("] throw =>", ex);
+            throw ex;
+        }
+        traceInterpreter("] return =>", rval);
+        return rval;
+    }
+
+    //** This transform is applied (statically) to every name.function. */
+    /*
+    private static MethodHandle eraseSubwordTypes(MethodHandle mh) {
+        MethodType mt = mh.type();
+        if (mt.hasPrimitives()) {
+            mt = mt.changeReturnType(eraseSubwordType(mt.returnType()));
+            for (int i = 0; i < mt.parameterCount(); i++) {
+                mt = mt.changeParameterType(i, eraseSubwordType(mt.parameterType(i)));
+            }
+            mh = MethodHandles.explicitCastArguments(mh, mt);
+        }
+        return mh;
+    }
+    private static Class<?> eraseSubwordType(Class<?> type) {
+        if (!type.isPrimitive())  return type;
+        if (type == int.class)  return type;
+        Wrapper w = Wrapper.forPrimitiveType(type);
+        if (w.isSubwordOrInt())  return int.class;
+        return type;
+    }
+    */
+
+    static void traceInterpreter(String event, Object obj, Object... args) {
+        if (TRACE_INTERPRETER) {
+            System.out.println("LFI: "+event+" "+(obj != null ? obj : "")+(args != null && args.length != 0 ? Arrays.asList(args) : ""));
+        }
+    }
+    static void traceInterpreter(String event, Object obj) {
+        traceInterpreter(event, obj, (Object[])null);
+    }
+    private boolean arityCheck(Object[] argumentValues) {
+        assert(argumentValues.length == arity) : arity+"!="+Arrays.asList(argumentValues)+".length";
+        // also check that the leading (receiver) argument is somehow bound to this LF:
+        assert(argumentValues[0] instanceof MethodHandle) : "not MH: " + argumentValues[0];
+        assert(((MethodHandle)argumentValues[0]).internalForm() == this);
+        // note:  argument #0 could also be an interface wrapper, in the future
+        return true;
+    }
+
+    private boolean isEmpty() {
+        if (result < 0)
+            return (names.length == arity);
+        else if (result == arity && names.length == arity + 1)
+            return names[arity].isConstantZero();
+        else
+            return false;
+    }
+
+    public String toString() {
+        StringBuilder buf = new StringBuilder(debugName+"=Lambda(");
+        for (int i = 0; i < names.length; i++) {
+            if (i == arity)  buf.append(")=>{");
+            Name n = names[i];
+            if (i >= arity)  buf.append("\n    ");
+            buf.append(n);
+            if (i < arity) {
+                if (i+1 < arity)  buf.append(",");
+                continue;
+            }
+            buf.append("=").append(n.exprString());
+            buf.append(";");
+        }
+        buf.append(result < 0 ? "void" : names[result]).append("}");
+        if (TRACE_INTERPRETER) {
+            // Extra verbosity:
+            buf.append(":").append(basicTypeSignature());
+            buf.append("/").append(vmentry);
+        }
+        return buf.toString();
+    }
+
+    /**
+     * Apply immediate binding for a Name in this form indicated by its position relative to the form.
+     * The first parameter to a LambdaForm, a0:L, always represents the form's method handle, so 0 is not
+     * accepted as valid.
+     */
+    LambdaForm bindImmediate(int pos, char basicType, Object value) {
+        // must be an argument, and the types must match
+        assert pos > 0 && pos < arity && names[pos].type == basicType && Name.typesMatch(basicType, value);
+
+        int arity2 = arity - 1;
+        Name[] names2 = new Name[names.length - 1];
+        for (int r = 0, w = 0; r < names.length; ++r, ++w) { // (r)ead from names, (w)rite to names2
+            Name n = names[r];
+            if (n.isParam()) {
+                if (n.index == pos) {
+                    // do not copy over the argument that is to be replaced with a literal,
+                    // but adjust the write index
+                    --w;
+                } else {
+                    names2[w] = new Name(w, n.type);
+                }
+            } else {
+                Object[] arguments2 = new Object[n.arguments.length];
+                for (int i = 0; i < n.arguments.length; ++i) {
+                    Object arg = n.arguments[i];
+                    if (arg instanceof Name) {
+                        int ni = ((Name) arg).index;
+                        if (ni == pos) {
+                            arguments2[i] = value;
+                        } else if (ni < pos) {
+                            // replacement position not yet passed
+                            arguments2[i] = names2[ni];
+                        } else {
+                            // replacement position passed
+                            arguments2[i] = names2[ni - 1];
+                        }
+                    } else {
+                        arguments2[i] = arg;
+                    }
+                }
+                names2[w] = new Name(n.function, arguments2);
+                names2[w].initIndex(w);
+            }
+        }
+
+        int result2 = result == -1 ? -1 : result - 1;
+        return new LambdaForm(debugName, arity2, names2, result2);
+    }
+
+    LambdaForm bind(int namePos, BoundMethodHandle.SpeciesData oldData) {
+        Name name = names[namePos];
+        BoundMethodHandle.SpeciesData newData = oldData.extendWithType(name.type);
+        return bind(name, newData.getterName(names[0], oldData.fieldCount()), oldData, newData);
+    }
+    LambdaForm bind(Name name, Name binding,
+                    BoundMethodHandle.SpeciesData oldData,
+                    BoundMethodHandle.SpeciesData newData) {
+        int pos = name.index;
+        assert(name.isParam());
+        assert(!binding.isParam());
+        assert(name.type == binding.type);
+        assert(0 <= pos && pos < arity && names[pos] == name);
+        assert(binding.function.memberDeclaringClassOrNull() == newData.clazz);
+        assert(oldData.getters.length == newData.getters.length-1);
+        if (bindCache != null) {
+            LambdaForm form = bindCache[pos];
+            if (form != null) {
+                assert(form.contains(binding)) : "form << " + form + " >> does not contain binding << " + binding + " >>";
+                return form;
+            }
+        } else {
+            bindCache = new LambdaForm[arity];
+        }
+        assert(nameRefsAreLegal());
+        int arity2 = arity-1;
+        Name[] names2 = names.clone();
+        names2[pos] = binding;  // we might move this in a moment
+
+        // The newly created LF will run with a different BMH.
+        // Switch over any pre-existing BMH field references to the new BMH class.
+        int firstOldRef = -1;
+        for (int i = 0; i < names2.length; i++) {
+            Name n = names[i];
+            if (n.function != null &&
+                n.function.memberDeclaringClassOrNull() == oldData.clazz) {
+                MethodHandle oldGetter = n.function.resolvedHandle;
+                MethodHandle newGetter = null;
+                for (int j = 0; j < oldData.getters.length; j++) {
+                    if (oldGetter == oldData.getters[j])
+                        newGetter =  newData.getters[j];
+                }
+                if (newGetter != null) {
+                    if (firstOldRef < 0)  firstOldRef = i;
+                    Name n2 = new Name(newGetter, n.arguments);
+                    names2[i] = n2;
+                }
+            }
+        }
+
+        // Walk over the new list of names once, in forward order.
+        // Replace references to 'name' with 'binding'.
+        // Replace data structure references to the old BMH species with the new.
+        // This might cause a ripple effect, but it will settle in one pass.
+        assert(firstOldRef < 0 || firstOldRef > pos);
+        for (int i = pos+1; i < names2.length; i++) {
+            if (i <= arity2)  continue;
+            names2[i] = names2[i].replaceNames(names, names2, pos, i);
+        }
+
+        //  (a0, a1, name=a2, a3, a4)  =>  (a0, a1, a3, a4, binding)
+        int insPos = pos;
+        for (; insPos+1 < names2.length; insPos++) {
+            Name n = names2[insPos+1];
+            if (n.isSiblingBindingBefore(binding)) {
+                names2[insPos] = n;
+            } else {
+                break;
+            }
+        }
+        names2[insPos] = binding;
+
+        // Since we moved some stuff, maybe update the result reference:
+        int result2 = result;
+        if (result2 == pos)
+            result2 = insPos;
+        else if (result2 > pos && result2 <= insPos)
+            result2 -= 1;
+
+        return bindCache[pos] = new LambdaForm(debugName, arity2, names2, result2);
+    }
+
+    boolean contains(Name name) {
+        int pos = name.index();
+        if (pos >= 0) {
+            return pos < names.length && name.equals(names[pos]);
+        }
+        for (int i = arity; i < names.length; i++) {
+            if (name.equals(names[i]))
+                return true;
+        }
+        return false;
+    }
+
+    LambdaForm addArguments(int pos, char... types) {
+        assert(pos <= arity);
+        int length = names.length;
+        int inTypes = types.length;
+        Name[] names2 = Arrays.copyOf(names, length + inTypes);
+        int arity2 = arity + inTypes;
+        int result2 = result;
+        if (result2 >= arity)
+            result2 += inTypes;
+        // names array has MH in slot 0; skip it.
+        int argpos = pos + 1;
+        // Note:  The LF constructor will rename names2[argpos...].
+        // Make space for new arguments (shift temporaries).
+        System.arraycopy(names, argpos, names2, argpos + inTypes, length - argpos);
+        for (int i = 0; i < inTypes; i++) {
+            names2[argpos + i] = new Name(types[i]);
+        }
+        return new LambdaForm(debugName, arity2, names2, result2);
+    }
+
+    LambdaForm addArguments(int pos, List<Class<?>> types) {
+        char[] basicTypes = new char[types.size()];
+        for (int i = 0; i < basicTypes.length; i++)
+            basicTypes[i] = basicType(types.get(i));
+        return addArguments(pos, basicTypes);
+    }
+
+    LambdaForm permuteArguments(int skip, int[] reorder, char[] types) {
+        // Note:  When inArg = reorder[outArg], outArg is fed by a copy of inArg.
+        // The types are the types of the new (incoming) arguments.
+        int length = names.length;
+        int inTypes = types.length;
+        int outArgs = reorder.length;
+        assert(skip+outArgs == arity);
+        assert(permutedTypesMatch(reorder, types, names, skip));
+        int pos = 0;
+        // skip trivial first part of reordering:
+        while (pos < outArgs && reorder[pos] == pos)  pos += 1;
+        Name[] names2 = new Name[length - outArgs + inTypes];
+        System.arraycopy(names, 0, names2, 0, skip+pos);
+        // copy the body:
+        int bodyLength = length - arity;
+        System.arraycopy(names, skip+outArgs, names2, skip+inTypes, bodyLength);
+        int arity2 = names2.length - bodyLength;
+        int result2 = result;
+        if (result2 >= 0) {
+            if (result2 < skip+outArgs) {
+                // return the corresponding inArg
+                result2 = reorder[result2-skip];
+            } else {
+                result2 = result2 - outArgs + inTypes;
+            }
+        }
+        // rework names in the body:
+        for (int j = pos; j < outArgs; j++) {
+            Name n = names[skip+j];
+            int i = reorder[j];
+            // replace names[skip+j] by names2[skip+i]
+            Name n2 = names2[skip+i];
+            if (n2 == null)
+                names2[skip+i] = n2 = new Name(types[i]);
+            else
+                assert(n2.type == types[i]);
+            for (int k = arity2; k < names2.length; k++) {
+                names2[k] = names2[k].replaceName(n, n2);
+            }
+        }
+        // some names are unused, but must be filled in
+        for (int i = skip+pos; i < arity2; i++) {
+            if (names2[i] == null)
+                names2[i] = argument(i, types[i - skip]);
+        }
+        for (int j = arity; j < names.length; j++) {
+            int i = j - arity + arity2;
+            // replace names2[i] by names[j]
+            Name n = names[j];
+            Name n2 = names2[i];
+            if (n != n2) {
+                for (int k = i+1; k < names2.length; k++) {
+                    names2[k] = names2[k].replaceName(n, n2);
+                }
+            }
+        }
+        return new LambdaForm(debugName, arity2, names2, result2);
+    }
+
+    static boolean permutedTypesMatch(int[] reorder, char[] types, Name[] names, int skip) {
+        int inTypes = types.length;
+        int outArgs = reorder.length;
+        for (int i = 0; i < outArgs; i++) {
+            assert(names[skip+i].isParam());
+            assert(names[skip+i].type == types[reorder[i]]);
+        }
+        return true;
+    }
+
+    static class NamedFunction {
+        final MemberName member;
+        @Stable MethodHandle resolvedHandle;
+        @Stable MethodHandle invoker;
+
+        NamedFunction(MethodHandle resolvedHandle) {
+            this(resolvedHandle.internalMemberName(), resolvedHandle);
+        }
+        NamedFunction(MemberName member, MethodHandle resolvedHandle) {
+            this.member = member;
+            //resolvedHandle = eraseSubwordTypes(resolvedHandle);
+            this.resolvedHandle = resolvedHandle;
+        }
+        NamedFunction(MethodType basicInvokerType) {
+            assert(basicInvokerType == basicInvokerType.basicType()) : basicInvokerType;
+            if (basicInvokerType.parameterSlotCount() < MethodType.MAX_MH_INVOKER_ARITY) {
+                this.resolvedHandle = basicInvokerType.invokers().basicInvoker();
+                this.member = resolvedHandle.internalMemberName();
+            } else {
+                // necessary to pass BigArityTest
+                this.member = Invokers.invokeBasicMethod(basicInvokerType);
+            }
+        }
+
+        // The next 3 constructors are used to break circular dependencies on MH.invokeStatic, etc.
+        // Any LambdaForm containing such a member is not interpretable.
+        // This is OK, since all such LFs are prepared with special primitive vmentry points.
+        // And even without the resolvedHandle, the name can still be compiled and optimized.
+        NamedFunction(Method method) {
+            this(new MemberName(method));
+        }
+        NamedFunction(Field field) {
+            this(new MemberName(field));
+        }
+        NamedFunction(MemberName member) {
+            this.member = member;
+            this.resolvedHandle = null;
+        }
+
+        MethodHandle resolvedHandle() {
+            if (resolvedHandle == null)  resolve();
+            return resolvedHandle;
+        }
+
+        void resolve() {
+            resolvedHandle = DirectMethodHandle.make(member);
+        }
+
+        @Override
+        public boolean equals(Object other) {
+            if (this == other) return true;
+            if (other == null) return false;
+            if (!(other instanceof NamedFunction)) return false;
+            NamedFunction that = (NamedFunction) other;
+            return this.member != null && this.member.equals(that.member);
+        }
+
+        @Override
+        public int hashCode() {
+            if (member != null)
+                return member.hashCode();
+            return super.hashCode();
+        }
+
+        // Put the predefined NamedFunction invokers into the table.
+        static void initializeInvokers() {
+            for (MemberName m : MemberName.getFactory().getMethods(NamedFunction.class, false, null, null, null)) {
+                if (!m.isStatic() || !m.isPackage())  continue;
+                MethodType type = m.getMethodType();
+                if (type.equals(INVOKER_METHOD_TYPE) &&
+                    m.getName().startsWith("invoke_")) {
+                    String sig = m.getName().substring("invoke_".length());
+                    int arity = LambdaForm.signatureArity(sig);
+                    MethodType srcType = MethodType.genericMethodType(arity);
+                    if (LambdaForm.signatureReturn(sig) == 'V')
+                        srcType = srcType.changeReturnType(void.class);
+                    MethodTypeForm typeForm = srcType.form();
+                    typeForm.namedFunctionInvoker = DirectMethodHandle.make(m);
+                }
+            }
+        }
+
+        // The following are predefined NamedFunction invokers.  The system must build
+        // a separate invoker for each distinct signature.
+        /** void return type invokers. */
+        @Hidden
+        static Object invoke__V(MethodHandle mh, Object[] a) throws Throwable {
+            assert(a.length == 0);
+            mh.invokeBasic();
+            return null;
+        }
+        @Hidden
+        static Object invoke_L_V(MethodHandle mh, Object[] a) throws Throwable {
+            assert(a.length == 1);
+            mh.invokeBasic(a[0]);
+            return null;
+        }
+        @Hidden
+        static Object invoke_LL_V(MethodHandle mh, Object[] a) throws Throwable {
+            assert(a.length == 2);
+            mh.invokeBasic(a[0], a[1]);
+            return null;
+        }
+        @Hidden
+        static Object invoke_LLL_V(MethodHandle mh, Object[] a) throws Throwable {
+            assert(a.length == 3);
+            mh.invokeBasic(a[0], a[1], a[2]);
+            return null;
+        }
+        @Hidden
+        static Object invoke_LLLL_V(MethodHandle mh, Object[] a) throws Throwable {
+            assert(a.length == 4);
+            mh.invokeBasic(a[0], a[1], a[2], a[3]);
+            return null;
+        }
+        @Hidden
+        static Object invoke_LLLLL_V(MethodHandle mh, Object[] a) throws Throwable {
+            assert(a.length == 5);
+            mh.invokeBasic(a[0], a[1], a[2], a[3], a[4]);
+            return null;
+        }
+        /** Object return type invokers. */
+        @Hidden
+        static Object invoke__L(MethodHandle mh, Object[] a) throws Throwable {
+            assert(a.length == 0);
+            return mh.invokeBasic();
+        }
+        @Hidden
+        static Object invoke_L_L(MethodHandle mh, Object[] a) throws Throwable {
+            assert(a.length == 1);
+            return mh.invokeBasic(a[0]);
+        }
+        @Hidden
+        static Object invoke_LL_L(MethodHandle mh, Object[] a) throws Throwable {
+            assert(a.length == 2);
+            return mh.invokeBasic(a[0], a[1]);
+        }
+        @Hidden
+        static Object invoke_LLL_L(MethodHandle mh, Object[] a) throws Throwable {
+            assert(a.length == 3);
+            return mh.invokeBasic(a[0], a[1], a[2]);
+        }
+        @Hidden
+        static Object invoke_LLLL_L(MethodHandle mh, Object[] a) throws Throwable {
+            assert(a.length == 4);
+            return mh.invokeBasic(a[0], a[1], a[2], a[3]);
+        }
+        @Hidden
+        static Object invoke_LLLLL_L(MethodHandle mh, Object[] a) throws Throwable {
+            assert(a.length == 5);
+            return mh.invokeBasic(a[0], a[1], a[2], a[3], a[4]);
+        }
+
+        static final MethodType INVOKER_METHOD_TYPE =
+            MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
+
+        private static MethodHandle computeInvoker(MethodTypeForm typeForm) {
+            MethodHandle mh = typeForm.namedFunctionInvoker;
+            if (mh != null)  return mh;
+            MemberName invoker = InvokerBytecodeGenerator.generateNamedFunctionInvoker(typeForm);  // this could take a while
+            mh = DirectMethodHandle.make(invoker);
+            MethodHandle mh2 = typeForm.namedFunctionInvoker;
+            if (mh2 != null)  return mh2;  // benign race
+            if (!mh.type().equals(INVOKER_METHOD_TYPE))
+                throw new InternalError(mh.debugString());
+            return typeForm.namedFunctionInvoker = mh;
+        }
+
+        @Hidden
+        Object invokeWithArguments(Object... arguments) throws Throwable {
+            // If we have a cached invoker, call it right away.
+            // NOTE: The invoker always returns a reference value.
+            if (TRACE_INTERPRETER)  return invokeWithArgumentsTracing(arguments);
+            assert(checkArgumentTypes(arguments, methodType()));
+            return invoker().invokeBasic(resolvedHandle(), arguments);
+        }
+
+        @Hidden
+        Object invokeWithArgumentsTracing(Object[] arguments) throws Throwable {
+            Object rval;
+            try {
+                traceInterpreter("[ call", this, arguments);
+                if (invoker == null) {
+                    traceInterpreter("| getInvoker", this);
+                    invoker();
+                }
+                if (resolvedHandle == null) {
+                    traceInterpreter("| resolve", this);
+                    resolvedHandle();
+                }
+                assert(checkArgumentTypes(arguments, methodType()));
+                rval = invoker().invokeBasic(resolvedHandle(), arguments);
+            } catch (Throwable ex) {
+                traceInterpreter("] throw =>", ex);
+                throw ex;
+            }
+            traceInterpreter("] return =>", rval);
+            return rval;
+        }
+
+        private MethodHandle invoker() {
+            if (invoker != null)  return invoker;
+            // Get an invoker and cache it.
+            return invoker = computeInvoker(methodType().form());
+        }
+
+        private static boolean checkArgumentTypes(Object[] arguments, MethodType methodType) {
+            if (true)  return true;  // FIXME
+            MethodType dstType = methodType.form().erasedType();
+            MethodType srcType = dstType.basicType().wrap();
+            Class<?>[] ptypes = new Class<?>[arguments.length];
+            for (int i = 0; i < arguments.length; i++) {
+                Object arg = arguments[i];
+                Class<?> ptype = arg == null ? Object.class : arg.getClass();
+                // If the dest. type is a primitive we keep the
+                // argument type.
+                ptypes[i] = dstType.parameterType(i).isPrimitive() ? ptype : Object.class;
+            }
+            MethodType argType = MethodType.methodType(srcType.returnType(), ptypes).wrap();
+            assert(argType.isConvertibleTo(srcType)) : "wrong argument types: cannot convert " + argType + " to " + srcType;
+            return true;
+        }
+
+        String basicTypeSignature() {
+            //return LambdaForm.basicTypeSignature(resolvedHandle.type());
+            return LambdaForm.basicTypeSignature(methodType());
+        }
+
+        MethodType methodType() {
+            if (resolvedHandle != null)
+                return resolvedHandle.type();
+            else
+                // only for certain internal LFs during bootstrapping
+                return member.getInvocationType();
+        }
+
+        MemberName member() {
+            assert(assertMemberIsConsistent());
+            return member;
+        }
+
+        // Called only from assert.
+        private boolean assertMemberIsConsistent() {
+            if (resolvedHandle instanceof DirectMethodHandle) {
+                MemberName m = resolvedHandle.internalMemberName();
+                assert(m.equals(member));
+            }
+            return true;
+        }
+
+        Class<?> memberDeclaringClassOrNull() {
+            return (member == null) ? null : member.getDeclaringClass();
+        }
+
+        char returnType() {
+            return basicType(methodType().returnType());
+        }
+
+        char parameterType(int n) {
+            return basicType(methodType().parameterType(n));
+        }
+
+        int arity() {
+            //int siglen = member.getMethodType().parameterCount();
+            //if (!member.isStatic())  siglen += 1;
+            //return siglen;
+            return methodType().parameterCount();
+        }
+
+        public String toString() {
+            if (member == null)  return String.valueOf(resolvedHandle);
+            return member.getDeclaringClass().getSimpleName()+"."+member.getName();
+        }
+    }
+
+    void resolve() {
+        for (Name n : names) n.resolve();
+    }
+
+    public static char basicType(Class<?> type) {
+        char c = Wrapper.basicTypeChar(type);
+        if ("ZBSC".indexOf(c) >= 0)  c = 'I';
+        assert("LIJFDV".indexOf(c) >= 0);
+        return c;
+    }
+    public static char[] basicTypes(List<Class<?>> types) {
+        char[] btypes = new char[types.size()];
+        for (int i = 0; i < btypes.length; i++) {
+            btypes[i] = basicType(types.get(i));
+        }
+        return btypes;
+    }
+    public static String basicTypeSignature(MethodType type) {
+        char[] sig = new char[type.parameterCount() + 2];
+        int sigp = 0;
+        for (Class<?> pt : type.parameterList()) {
+            sig[sigp++] = basicType(pt);
+        }
+        sig[sigp++] = '_';
+        sig[sigp++] = basicType(type.returnType());
+        assert(sigp == sig.length);
+        return String.valueOf(sig);
+    }
+
+    static final class Name {
+        final char type;
+        private short index;
+        final NamedFunction function;
+        @Stable final Object[] arguments;
+
+        private Name(int index, char type, NamedFunction function, Object[] arguments) {
+            this.index = (short)index;
+            this.type = type;
+            this.function = function;
+            this.arguments = arguments;
+            assert(this.index == index);
+        }
+        Name(MethodHandle function, Object... arguments) {
+            this(new NamedFunction(function), arguments);
+        }
+        Name(MethodType functionType, Object... arguments) {
+            this(new NamedFunction(functionType), arguments);
+            assert(arguments[0] instanceof Name && ((Name)arguments[0]).type == 'L');
+        }
+        Name(MemberName function, Object... arguments) {
+            this(new NamedFunction(function), arguments);
+        }
+        Name(NamedFunction function, Object... arguments) {
+            this(-1, function.returnType(), function, arguments = arguments.clone());
+            assert(arguments.length == function.arity()) : "arity mismatch: arguments.length=" + arguments.length + " == function.arity()=" + function.arity() + " in " + debugString();
+            for (int i = 0; i < arguments.length; i++)
+                assert(typesMatch(function.parameterType(i), arguments[i])) : "types don't match: function.parameterType(" + i + ")=" + function.parameterType(i) + ", arguments[" + i + "]=" + arguments[i] + " in " + debugString();
+        }
+        Name(int index, char type) {
+            this(index, type, null, null);
+        }
+        Name(char type) {
+            this(-1, type);
+        }
+
+        char type() { return type; }
+        int index() { return index; }
+        boolean initIndex(int i) {
+            if (index != i) {
+                if (index != -1)  return false;
+                index = (short)i;
+            }
+            return true;
+        }
+
+
+        void resolve() {
+            if (function != null)
+                function.resolve();
+        }
+
+        Name newIndex(int i) {
+            if (initIndex(i))  return this;
+            return cloneWithIndex(i);
+        }
+        Name cloneWithIndex(int i) {
+            Object[] newArguments = (arguments == null) ? null : arguments.clone();
+            return new Name(i, type, function, newArguments);
+        }
+        Name replaceName(Name oldName, Name newName) {  // FIXME: use replaceNames uniformly
+            if (oldName == newName)  return this;
+            @SuppressWarnings("LocalVariableHidesMemberVariable")
+            Object[] arguments = this.arguments;
+            if (arguments == null)  return this;
+            boolean replaced = false;
+            for (int j = 0; j < arguments.length; j++) {
+                if (arguments[j] == oldName) {
+                    if (!replaced) {
+                        replaced = true;
+                        arguments = arguments.clone();
+                    }
+                    arguments[j] = newName;
+                }
+            }
+            if (!replaced)  return this;
+            return new Name(function, arguments);
+        }
+        Name replaceNames(Name[] oldNames, Name[] newNames, int start, int end) {
+            @SuppressWarnings("LocalVariableHidesMemberVariable")
+            Object[] arguments = this.arguments;
+            boolean replaced = false;
+        eachArg:
+            for (int j = 0; j < arguments.length; j++) {
+                if (arguments[j] instanceof Name) {
+                    Name n = (Name) arguments[j];
+                    int check = n.index;
+                    // harmless check to see if the thing is already in newNames:
+                    if (check >= 0 && check < newNames.length && n == newNames[check])
+                        continue eachArg;
+                    // n might not have the correct index: n != oldNames[n.index].
+                    for (int i = start; i < end; i++) {
+                        if (n == oldNames[i]) {
+                            if (n == newNames[i])
+                                continue eachArg;
+                            if (!replaced) {
+                                replaced = true;
+                                arguments = arguments.clone();
+                            }
+                            arguments[j] = newNames[i];
+                            continue eachArg;
+                        }
+                    }
+                }
+            }
+            if (!replaced)  return this;
+            return new Name(function, arguments);
+        }
+        void internArguments() {
+            @SuppressWarnings("LocalVariableHidesMemberVariable")
+            Object[] arguments = this.arguments;
+            for (int j = 0; j < arguments.length; j++) {
+                if (arguments[j] instanceof Name) {
+                    Name n = (Name) arguments[j];
+                    if (n.isParam() && n.index < INTERNED_ARGUMENT_LIMIT)
+                        arguments[j] = internArgument(n);
+                }
+            }
+        }
+        boolean isParam() {
+            return function == null;
+        }
+        boolean isConstantZero() {
+            return !isParam() && arguments.length == 0 && function.equals(constantZero(0, type).function);
+        }
+
+        public String toString() {
+            return (isParam()?"a":"t")+(index >= 0 ? index : System.identityHashCode(this))+":"+type;
+        }
+        public String debugString() {
+            String s = toString();
+            return (function == null) ? s : s + "=" + exprString();
+        }
+        public String exprString() {
+            if (function == null)  return "null";
+            StringBuilder buf = new StringBuilder(function.toString());
+            buf.append("(");
+            String cma = "";
+            for (Object a : arguments) {
+                buf.append(cma); cma = ",";
+                if (a instanceof Name || a instanceof Integer)
+                    buf.append(a);
+                else
+                    buf.append("(").append(a).append(")");
+            }
+            buf.append(")");
+            return buf.toString();
+        }
+
+        private static boolean typesMatch(char parameterType, Object object) {
+            if (object instanceof Name) {
+                return ((Name)object).type == parameterType;
+            }
+            switch (parameterType) {
+                case 'I':  return object instanceof Integer;
+                case 'J':  return object instanceof Long;
+                case 'F':  return object instanceof Float;
+                case 'D':  return object instanceof Double;
+            }
+            assert(parameterType == 'L');
+            return true;
+        }
+
+        /**
+         * Does this Name precede the given binding node in some canonical order?
+         * This predicate is used to order data bindings (via insertion sort)
+         * with some stability.
+         */
+        boolean isSiblingBindingBefore(Name binding) {
+            assert(!binding.isParam());
+            if (isParam())  return true;
+            if (function.equals(binding.function) &&
+                arguments.length == binding.arguments.length) {
+                boolean sawInt = false;
+                for (int i = 0; i < arguments.length; i++) {
+                    Object a1 = arguments[i];
+                    Object a2 = binding.arguments[i];
+                    if (!a1.equals(a2)) {
+                        if (a1 instanceof Integer && a2 instanceof Integer) {
+                            if (sawInt)  continue;
+                            sawInt = true;
+                            if ((int)a1 < (int)a2)  continue;  // still might be true
+                        }
+                        return false;
+                    }
+                }
+                return sawInt;
+            }
+            return false;
+        }
+
+        public boolean equals(Name that) {
+            if (this == that)  return true;
+            if (isParam())
+                // each parameter is a unique atom
+                return false;  // this != that
+            return
+                //this.index == that.index &&
+                this.type == that.type &&
+                this.function.equals(that.function) &&
+                Arrays.equals(this.arguments, that.arguments);
+        }
+        @Override
+        public boolean equals(Object x) {
+            return x instanceof Name && equals((Name)x);
+        }
+        @Override
+        public int hashCode() {
+            if (isParam())
+                return index | (type << 8);
+            return function.hashCode() ^ Arrays.hashCode(arguments);
+        }
+    }
+
+    static Name argument(int which, char type) {
+        int tn = ALL_TYPES.indexOf(type);
+        if (tn < 0 || which >= INTERNED_ARGUMENT_LIMIT)
+            return new Name(which, type);
+        return INTERNED_ARGUMENTS[tn][which];
+    }
+    static Name internArgument(Name n) {
+        assert(n.isParam()) : "not param: " + n;
+        assert(n.index < INTERNED_ARGUMENT_LIMIT);
+        return argument(n.index, n.type);
+    }
+    static Name[] arguments(int extra, String types) {
+        int length = types.length();
+        Name[] names = new Name[length + extra];
+        for (int i = 0; i < length; i++)
+            names[i] = argument(i, types.charAt(i));
+        return names;
+    }
+    static Name[] arguments(int extra, char... types) {
+        int length = types.length;
+        Name[] names = new Name[length + extra];
+        for (int i = 0; i < length; i++)
+            names[i] = argument(i, types[i]);
+        return names;
+    }
+    static Name[] arguments(int extra, List<Class<?>> types) {
+        int length = types.size();
+        Name[] names = new Name[length + extra];
+        for (int i = 0; i < length; i++)
+            names[i] = argument(i, basicType(types.get(i)));
+        return names;
+    }
+    static Name[] arguments(int extra, Class<?>... types) {
+        int length = types.length;
+        Name[] names = new Name[length + extra];
+        for (int i = 0; i < length; i++)
+            names[i] = argument(i, basicType(types[i]));
+        return names;
+    }
+    static Name[] arguments(int extra, MethodType types) {
+        int length = types.parameterCount();
+        Name[] names = new Name[length + extra];
+        for (int i = 0; i < length; i++)
+            names[i] = argument(i, basicType(types.parameterType(i)));
+        return names;
+    }
+    static final String ALL_TYPES = "LIJFD";  // omit V, not an argument type
+    static final int INTERNED_ARGUMENT_LIMIT = 10;
+    private static final Name[][] INTERNED_ARGUMENTS
+            = new Name[ALL_TYPES.length()][INTERNED_ARGUMENT_LIMIT];
+    static {
+        for (int tn = 0; tn < ALL_TYPES.length(); tn++) {
+            for (int i = 0; i < INTERNED_ARGUMENTS[tn].length; i++) {
+                char type = ALL_TYPES.charAt(tn);
+                INTERNED_ARGUMENTS[tn][i] = new Name(i, type);
+            }
+        }
+    }
+
+    private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
+
+    static Name constantZero(int which, char type) {
+        return CONSTANT_ZERO[ALL_TYPES.indexOf(type)].newIndex(which);
+    }
+    private static final Name[] CONSTANT_ZERO
+            = new Name[ALL_TYPES.length()];
+    static {
+        for (int tn = 0; tn < ALL_TYPES.length(); tn++) {
+            char bt = ALL_TYPES.charAt(tn);
+            Wrapper wrap = Wrapper.forBasicType(bt);
+            MemberName zmem = new MemberName(LambdaForm.class, "zero"+bt, MethodType.methodType(wrap.primitiveType()), REF_invokeStatic);
+            try {
+                zmem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, zmem, null, NoSuchMethodException.class);
+            } catch (IllegalAccessException|NoSuchMethodException ex) {
+                throw newInternalError(ex);
+            }
+            NamedFunction zcon = new NamedFunction(zmem);
+            Name n = new Name(zcon).newIndex(0);
+            assert(n.type == ALL_TYPES.charAt(tn));
+            CONSTANT_ZERO[tn] = n;
+            assert(n.isConstantZero());
+        }
+    }
+
+    // Avoid appealing to ValueConversions at bootstrap time:
+    private static int zeroI() { return 0; }
+    private static long zeroJ() { return 0; }
+    private static float zeroF() { return 0; }
+    private static double zeroD() { return 0; }
+    private static Object zeroL() { return null; }
+
+    // Put this last, so that previous static inits can run before.
+    static {
+        if (USE_PREDEFINED_INTERPRET_METHODS)
+            PREPARED_FORMS.putAll(computeInitialPreparedForms());
+    }
+
+    /**
+     * Internal marker for byte-compiled LambdaForms.
+     */
+    /*non-public*/
+    @Target(ElementType.METHOD)
+    @Retention(RetentionPolicy.RUNTIME)
+    @interface Compiled {
+    }
+
+    /**
+     * Internal marker for LambdaForm interpreter frames.
+     */
+    /*non-public*/
+    @Target(ElementType.METHOD)
+    @Retention(RetentionPolicy.RUNTIME)
+    @interface Hidden {
+    }
+
+
+/*
+    // Smoke-test for the invokers used in this file.
+    static void testMethodHandleLinkers() throws Throwable {
+        MemberName.Factory lookup = MemberName.getFactory();
+        MemberName asList_MN = new MemberName(Arrays.class, "asList",
+                                              MethodType.methodType(List.class, Object[].class),
+                                              REF_invokeStatic);
+        //MethodHandleNatives.resolve(asList_MN, null);
+        asList_MN = lookup.resolveOrFail(asList_MN, REF_invokeStatic, null, NoSuchMethodException.class);
+        System.out.println("about to call "+asList_MN);
+        Object[] abc = { "a", "bc" };
+        List<?> lst = (List<?>) MethodHandle.linkToStatic(abc, asList_MN);
+        System.out.println("lst="+lst);
+        MemberName toString_MN = new MemberName(Object.class.getMethod("toString"));
+        String s1 = (String) MethodHandle.linkToVirtual(lst, toString_MN);
+        toString_MN = new MemberName(Object.class.getMethod("toString"), true);
+        String s2 = (String) MethodHandle.linkToSpecial(lst, toString_MN);
+        System.out.println("[s1,s2,lst]="+Arrays.asList(s1, s2, lst.toString()));
+        MemberName toArray_MN = new MemberName(List.class.getMethod("toArray"));
+        Object[] arr = (Object[]) MethodHandle.linkToInterface(lst, toArray_MN);
+        System.out.println("toArray="+Arrays.toString(arr));
+    }
+    static { try { testMethodHandleLinkers(); } catch (Throwable ex) { throw new RuntimeException(ex); } }
+    // Requires these definitions in MethodHandle:
+    static final native Object linkToStatic(Object x1, MemberName mn) throws Throwable;
+    static final native Object linkToVirtual(Object x1, MemberName mn) throws Throwable;
+    static final native Object linkToSpecial(Object x1, MemberName mn) throws Throwable;
+    static final native Object linkToInterface(Object x1, MemberName mn) throws Throwable;
+ */
+
+    static { NamedFunction.initializeInvokers(); }
+
+    // The following hack is necessary in order to suppress TRACE_INTERPRETER
+    // during execution of the static initializes of this class.
+    // Turning on TRACE_INTERPRETER too early will cause
+    // stack overflows and other misbehavior during attempts to trace events
+    // that occur during LambdaForm.<clinit>.
+    // Therefore, do not move this line higher in this file, and do not remove.
+    private static final boolean TRACE_INTERPRETER = MethodHandleStatics.TRACE_INTERPRETER;
+}