1 /*
2 * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang.invoke;
27
28 import java.lang.annotation.*;
29 import java.lang.reflect.Method;
30 import java.util.List;
31 import java.util.Arrays;
32 import java.util.HashMap;
33
34 import sun.invoke.util.Wrapper;
35 import java.lang.reflect.Field;
36
37 import static java.lang.invoke.LambdaForm.BasicType.*;
38 import static java.lang.invoke.MethodHandleStatics.*;
39 import static java.lang.invoke.MethodHandleNatives.Constants.*;
40
41 /**
42 * The symbolic, non-executable form of a method handle's invocation semantics.
43 * It consists of a series of names.
44 * The first N (N=arity) names are parameters,
45 * while any remaining names are temporary values.
46 * Each temporary specifies the application of a function to some arguments.
47 * The functions are method handles, while the arguments are mixes of
48 * constant values and local names.
49 * The result of the lambda is defined as one of the names, often the last one.
50 * <p>
51 * Here is an approximate grammar:
52 * <blockquote><pre>{@code
53 * LambdaForm = "(" ArgName* ")=>{" TempName* Result "}"
54 * ArgName = "a" N ":" T
55 * TempName = "t" N ":" T "=" Function "(" Argument* ");"
56 * Function = ConstantValue
57 * Argument = NameRef | ConstantValue
58 * Result = NameRef | "void"
59 * NameRef = "a" N | "t" N
60 * N = (any whole number)
61 * T = "L" | "I" | "J" | "F" | "D" | "V"
62 * }</pre></blockquote>
63 * Names are numbered consecutively from left to right starting at zero.
64 * (The letters are merely a taste of syntax sugar.)
65 * Thus, the first temporary (if any) is always numbered N (where N=arity).
66 * Every occurrence of a name reference in an argument list must refer to
67 * a name previously defined within the same lambda.
68 * A lambda has a void result if and only if its result index is -1.
69 * If a temporary has the type "V", it cannot be the subject of a NameRef,
70 * even though possesses a number.
71 * Note that all reference types are erased to "L", which stands for {@code Object}.
72 * All subword types (boolean, byte, short, char) are erased to "I" which is {@code int}.
73 * The other types stand for the usual primitive types.
74 * <p>
75 * Function invocation closely follows the static rules of the Java verifier.
76 * Arguments and return values must exactly match when their "Name" types are
77 * considered.
78 * Conversions are allowed only if they do not change the erased type.
79 * <ul>
80 * <li>L = Object: casts are used freely to convert into and out of reference types
81 * <li>I = int: subword types are forcibly narrowed when passed as arguments (see {@code explicitCastArguments})
82 * <li>J = long: no implicit conversions
83 * <li>F = float: no implicit conversions
84 * <li>D = double: no implicit conversions
85 * <li>V = void: a function result may be void if and only if its Name is of type "V"
86 * </ul>
87 * Although implicit conversions are not allowed, explicit ones can easily be
88 * encoded by using temporary expressions which call type-transformed identity functions.
89 * <p>
90 * Examples:
91 * <blockquote><pre>{@code
92 * (a0:J)=>{ a0 }
93 * == identity(long)
94 * (a0:I)=>{ t1:V = System.out#println(a0); void }
95 * == System.out#println(int)
96 * (a0:L)=>{ t1:V = System.out#println(a0); a0 }
97 * == identity, with printing side-effect
98 * (a0:L, a1:L)=>{ t2:L = BoundMethodHandle#argument(a0);
99 * t3:L = BoundMethodHandle#target(a0);
100 * t4:L = MethodHandle#invoke(t3, t2, a1); t4 }
101 * == general invoker for unary insertArgument combination
102 * (a0:L, a1:L)=>{ t2:L = FilterMethodHandle#filter(a0);
103 * t3:L = MethodHandle#invoke(t2, a1);
104 * t4:L = FilterMethodHandle#target(a0);
105 * t5:L = MethodHandle#invoke(t4, t3); t5 }
106 * == general invoker for unary filterArgument combination
107 * (a0:L, a1:L)=>{ ...(same as previous example)...
108 * t5:L = MethodHandle#invoke(t4, t3, a1); t5 }
109 * == general invoker for unary/unary foldArgument combination
110 * (a0:L, a1:I)=>{ t2:I = identity(long).asType((int)->long)(a1); t2 }
111 * == invoker for identity method handle which performs i2l
112 * (a0:L, a1:L)=>{ t2:L = BoundMethodHandle#argument(a0);
113 * t3:L = Class#cast(t2,a1); t3 }
114 * == invoker for identity method handle which performs cast
115 * }</pre></blockquote>
116 * <p>
117 * @author John Rose, JSR 292 EG
118 */
119 class LambdaForm {
120 final int arity;
121 final int result;
122 @Stable final Name[] names;
123 final String debugName;
124 MemberName vmentry; // low-level behavior, or null if not yet prepared
125 private boolean isCompiled;
126
127 // Caches for common structural transforms:
128 LambdaForm[] bindCache;
129
130 public static final int VOID_RESULT = -1, LAST_RESULT = -2;
131
132 enum BasicType {
133 L_TYPE('L', Object.class, Wrapper.OBJECT), // all reference types
134 I_TYPE('I', int.class, Wrapper.INT),
135 J_TYPE('J', long.class, Wrapper.LONG),
136 F_TYPE('F', float.class, Wrapper.FLOAT),
137 D_TYPE('D', double.class, Wrapper.DOUBLE), // all primitive types
138 V_TYPE('V', void.class, Wrapper.VOID); // not valid in all contexts
139
140 static final BasicType[] ALL_TYPES = BasicType.values();
141 static final BasicType[] ARG_TYPES = Arrays.copyOf(ALL_TYPES, ALL_TYPES.length-1);
142
143 static final int ARG_TYPE_LIMIT = ARG_TYPES.length;
144 static final int TYPE_LIMIT = ALL_TYPES.length;
145
146 private final char btChar;
147 private final Class<?> btClass;
148 private final Wrapper btWrapper;
149
150 private BasicType(char btChar, Class<?> btClass, Wrapper wrapper) {
151 this.btChar = btChar;
152 this.btClass = btClass;
153 this.btWrapper = wrapper;
154 }
155
156 char basicTypeChar() {
157 return btChar;
158 }
159 Class<?> basicTypeClass() {
160 return btClass;
161 }
162 Wrapper basicTypeWrapper() {
163 return btWrapper;
164 }
165 int basicTypeSlots() {
166 return btWrapper.stackSlots();
167 }
168
169 static BasicType basicType(byte type) {
170 return ALL_TYPES[type];
171 }
172 static BasicType basicType(char type) {
173 switch (type) {
174 case 'L': return L_TYPE;
175 case 'I': return I_TYPE;
176 case 'J': return J_TYPE;
177 case 'F': return F_TYPE;
178 case 'D': return D_TYPE;
179 case 'V': return V_TYPE;
180 // all subword types are represented as ints
181 case 'Z':
182 case 'B':
183 case 'S':
184 case 'C':
185 return I_TYPE;
186 default:
187 throw newInternalError("Unknown type char: '"+type+"'");
188 }
189 }
190 static BasicType basicType(Wrapper type) {
191 char c = type.basicTypeChar();
192 return basicType(c);
193 }
194 static BasicType basicType(Class<?> type) {
195 if (!type.isPrimitive()) return L_TYPE;
196 return basicType(Wrapper.forPrimitiveType(type));
197 }
198
199 static char basicTypeChar(Class<?> type) {
200 return basicType(type).btChar;
201 }
202 static BasicType[] basicTypes(List<Class<?>> types) {
203 BasicType[] btypes = new BasicType[types.size()];
204 for (int i = 0; i < btypes.length; i++) {
205 btypes[i] = basicType(types.get(i));
206 }
207 return btypes;
208 }
209 static BasicType[] basicTypes(String types) {
210 BasicType[] btypes = new BasicType[types.length()];
211 for (int i = 0; i < btypes.length; i++) {
212 btypes[i] = basicType(types.charAt(i));
213 }
214 return btypes;
215 }
216 static boolean isBasicTypeChar(char c) {
217 return "LIJFDV".indexOf(c) >= 0;
218 }
219 static boolean isArgBasicTypeChar(char c) {
220 return "LIJFD".indexOf(c) >= 0;
221 }
222
223 static { assert(checkBasicType()); }
224 private static boolean checkBasicType() {
225 for (int i = 0; i < ARG_TYPE_LIMIT; i++) {
226 assert ARG_TYPES[i].ordinal() == i;
227 assert ARG_TYPES[i] == ALL_TYPES[i];
228 }
229 for (int i = 0; i < TYPE_LIMIT; i++) {
230 assert ALL_TYPES[i].ordinal() == i;
231 }
232 assert ALL_TYPES[TYPE_LIMIT - 1] == V_TYPE;
233 assert !Arrays.asList(ARG_TYPES).contains(V_TYPE);
234 return true;
235 }
236 }
237
238 LambdaForm(String debugName,
239 int arity, Name[] names, int result) {
240 assert(namesOK(arity, names));
241 this.arity = arity;
242 this.result = fixResult(result, names);
243 this.names = names.clone();
244 this.debugName = fixDebugName(debugName);
245 int maxOutArity = normalize();
246 if (maxOutArity > MethodType.MAX_MH_INVOKER_ARITY) {
247 // Cannot use LF interpreter on very high arity expressions.
248 assert(maxOutArity <= MethodType.MAX_JVM_ARITY);
249 compileToBytecode();
250 }
251 }
252
253 LambdaForm(String debugName,
254 int arity, Name[] names) {
255 this(debugName,
256 arity, names, LAST_RESULT);
257 }
258
259 LambdaForm(String debugName,
260 Name[] formals, Name[] temps, Name result) {
261 this(debugName,
262 formals.length, buildNames(formals, temps, result), LAST_RESULT);
263 }
264
265 private static Name[] buildNames(Name[] formals, Name[] temps, Name result) {
266 int arity = formals.length;
267 int length = arity + temps.length + (result == null ? 0 : 1);
268 Name[] names = Arrays.copyOf(formals, length);
269 System.arraycopy(temps, 0, names, arity, temps.length);
270 if (result != null)
271 names[length - 1] = result;
272 return names;
273 }
274
275 private LambdaForm(String sig) {
276 // Make a blank lambda form, which returns a constant zero or null.
277 // It is used as a template for managing the invocation of similar forms that are non-empty.
278 // Called only from getPreparedForm.
279 assert(isValidSignature(sig));
280 this.arity = signatureArity(sig);
281 this.result = (signatureReturn(sig) == V_TYPE ? -1 : arity);
282 this.names = buildEmptyNames(arity, sig);
283 this.debugName = "LF.zero";
284 assert(nameRefsAreLegal());
285 assert(isEmpty());
286 assert(sig.equals(basicTypeSignature())) : sig + " != " + basicTypeSignature();
287 }
288
289 private static Name[] buildEmptyNames(int arity, String basicTypeSignature) {
290 assert(isValidSignature(basicTypeSignature));
291 int resultPos = arity + 1; // skip '_'
292 if (arity < 0 || basicTypeSignature.length() != resultPos+1)
293 throw new IllegalArgumentException("bad arity for "+basicTypeSignature);
294 int numRes = (basicType(basicTypeSignature.charAt(resultPos)) == V_TYPE ? 0 : 1);
295 Name[] names = arguments(numRes, basicTypeSignature.substring(0, arity));
296 for (int i = 0; i < numRes; i++) {
297 Name zero = new Name(constantZero(basicType(basicTypeSignature.charAt(resultPos + i))));
298 names[arity + i] = zero.newIndex(arity + i);
299 }
300 return names;
301 }
302
303 private static int fixResult(int result, Name[] names) {
304 if (result == LAST_RESULT)
305 result = names.length - 1; // might still be void
306 if (result >= 0 && names[result].type == V_TYPE)
307 result = VOID_RESULT;
308 return result;
309 }
310
311 private static String fixDebugName(String debugName) {
312 if (DEBUG_NAME_COUNTERS != null) {
313 int under = debugName.indexOf('_');
314 int length = debugName.length();
315 if (under < 0) under = length;
316 String debugNameStem = debugName.substring(0, under);
317 Integer ctr;
318 synchronized (DEBUG_NAME_COUNTERS) {
319 ctr = DEBUG_NAME_COUNTERS.get(debugNameStem);
320 if (ctr == null) ctr = 0;
321 DEBUG_NAME_COUNTERS.put(debugNameStem, ctr+1);
322 }
323 StringBuilder buf = new StringBuilder(debugNameStem);
324 buf.append('_');
325 int leadingZero = buf.length();
326 buf.append((int) ctr);
327 for (int i = buf.length() - leadingZero; i < 3; i++)
328 buf.insert(leadingZero, '0');
329 if (under < length) {
330 ++under; // skip "_"
331 while (under < length && Character.isDigit(debugName.charAt(under))) {
332 ++under;
333 }
334 if (under < length && debugName.charAt(under) == '_') ++under;
335 if (under < length)
336 buf.append('_').append(debugName, under, length);
337 }
338 return buf.toString();
339 }
340 return debugName;
341 }
342
343 private static boolean namesOK(int arity, Name[] names) {
344 for (int i = 0; i < names.length; i++) {
345 Name n = names[i];
346 assert(n != null) : "n is null";
347 if (i < arity)
348 assert( n.isParam()) : n + " is not param at " + i;
349 else
350 assert(!n.isParam()) : n + " is param at " + i;
351 }
352 return true;
353 }
354
355 /** Renumber and/or replace params so that they are interned and canonically numbered.
356 * @return maximum argument list length among the names (since we have to pass over them anyway)
357 */
358 private int normalize() {
359 Name[] oldNames = null;
360 int maxOutArity = 0;
361 int changesStart = 0;
362 for (int i = 0; i < names.length; i++) {
363 Name n = names[i];
364 if (!n.initIndex(i)) {
365 if (oldNames == null) {
366 oldNames = names.clone();
367 changesStart = i;
368 }
369 names[i] = n.cloneWithIndex(i);
370 }
371 if (n.arguments != null && maxOutArity < n.arguments.length)
372 maxOutArity = n.arguments.length;
373 }
374 if (oldNames != null) {
375 int startFixing = arity;
376 if (startFixing <= changesStart)
377 startFixing = changesStart+1;
378 for (int i = startFixing; i < names.length; i++) {
379 Name fixed = names[i].replaceNames(oldNames, names, changesStart, i);
380 names[i] = fixed.newIndex(i);
381 }
382 }
383 assert(nameRefsAreLegal());
384 int maxInterned = Math.min(arity, INTERNED_ARGUMENT_LIMIT);
385 boolean needIntern = false;
386 for (int i = 0; i < maxInterned; i++) {
387 Name n = names[i], n2 = internArgument(n);
388 if (n != n2) {
389 names[i] = n2;
390 needIntern = true;
391 }
392 }
393 if (needIntern) {
394 for (int i = arity; i < names.length; i++) {
395 names[i].internArguments();
396 }
397 assert(nameRefsAreLegal());
398 }
399 return maxOutArity;
400 }
401
402 /**
403 * Check that all embedded Name references are localizable to this lambda,
404 * and are properly ordered after their corresponding definitions.
405 * <p>
406 * Note that a Name can be local to multiple lambdas, as long as
407 * it possesses the same index in each use site.
408 * This allows Name references to be freely reused to construct
409 * fresh lambdas, without confusion.
410 */
411 private boolean nameRefsAreLegal() {
412 assert(arity >= 0 && arity <= names.length);
413 assert(result >= -1 && result < names.length);
414 // Do all names possess an index consistent with their local definition order?
415 for (int i = 0; i < arity; i++) {
416 Name n = names[i];
417 assert(n.index() == i) : Arrays.asList(n.index(), i);
418 assert(n.isParam());
419 }
420 // Also, do all local name references
421 for (int i = arity; i < names.length; i++) {
422 Name n = names[i];
423 assert(n.index() == i);
424 for (Object arg : n.arguments) {
425 if (arg instanceof Name) {
426 Name n2 = (Name) arg;
427 int i2 = n2.index;
428 assert(0 <= i2 && i2 < names.length) : n.debugString() + ": 0 <= i2 && i2 < names.length: 0 <= " + i2 + " < " + names.length;
429 assert(names[i2] == n2) : Arrays.asList("-1-", i, "-2-", n.debugString(), "-3-", i2, "-4-", n2.debugString(), "-5-", names[i2].debugString(), "-6-", this);
430 assert(i2 < i); // ref must come after def!
431 }
432 }
433 }
434 return true;
435 }
436
437 /** Invoke this form on the given arguments. */
438 // final Object invoke(Object... args) throws Throwable {
439 // // NYI: fit this into the fast path?
440 // return interpretWithArguments(args);
441 // }
442
443 /** Report the return type. */
444 BasicType returnType() {
445 if (result < 0) return V_TYPE;
446 Name n = names[result];
447 return n.type;
448 }
449
450 /** Report the N-th argument type. */
451 BasicType parameterType(int n) {
452 return parameter(n).type;
453 }
454
455 /** Report the N-th argument name. */
456 Name parameter(int n) {
457 assert(n < arity);
458 Name param = names[n];
459 assert(param.isParam());
460 return param;
461 }
462
463 /** Report the N-th argument type constraint. */
464 Object parameterConstraint(int n) {
465 return parameter(n).constraint;
466 }
467
468 /** Report the arity. */
469 int arity() {
470 return arity;
471 }
472
473 /** Report the number of expressions (non-parameter names). */
474 int expressionCount() {
475 return names.length - arity;
476 }
477
478 /** Return the method type corresponding to my basic type signature. */
479 MethodType methodType() {
480 return signatureType(basicTypeSignature());
481 }
482 /** Return ABC_Z, where the ABC are parameter type characters, and Z is the return type character. */
483 final String basicTypeSignature() {
484 StringBuilder buf = new StringBuilder(arity() + 3);
485 for (int i = 0, a = arity(); i < a; i++)
486 buf.append(parameterType(i).basicTypeChar());
487 return buf.append('_').append(returnType().basicTypeChar()).toString();
488 }
489 static int signatureArity(String sig) {
490 assert(isValidSignature(sig));
491 return sig.indexOf('_');
492 }
493 static BasicType signatureReturn(String sig) {
494 return basicType(sig.charAt(signatureArity(sig) + 1));
495 }
496 static boolean isValidSignature(String sig) {
497 int arity = sig.indexOf('_');
498 if (arity < 0) return false; // must be of the form *_*
499 int siglen = sig.length();
500 if (siglen != arity + 2) return false; // *_X
501 for (int i = 0; i < siglen; i++) {
502 if (i == arity) continue; // skip '_'
503 char c = sig.charAt(i);
504 if (c == 'V')
505 return (i == siglen - 1 && arity == siglen - 2);
506 if (!isArgBasicTypeChar(c)) return false; // must be [LIJFD]
507 }
508 return true; // [LIJFD]*_[LIJFDV]
509 }
510 static MethodType signatureType(String sig) {
511 Class<?>[] ptypes = new Class<?>[signatureArity(sig)];
512 for (int i = 0; i < ptypes.length; i++)
513 ptypes[i] = basicType(sig.charAt(i)).btClass;
514 Class<?> rtype = signatureReturn(sig).btClass;
515 return MethodType.methodType(rtype, ptypes);
516 }
517
518 /*
519 * Code generation issues:
520 *
521 * Compiled LFs should be reusable in general.
522 * The biggest issue is how to decide when to pull a name into
523 * the bytecode, versus loading a reified form from the MH data.
524 *
525 * For example, an asType wrapper may require execution of a cast
526 * after a call to a MH. The target type of the cast can be placed
527 * as a constant in the LF itself. This will force the cast type
528 * to be compiled into the bytecodes and native code for the MH.
529 * Or, the target type of the cast can be erased in the LF, and
530 * loaded from the MH data. (Later on, if the MH as a whole is
531 * inlined, the data will flow into the inlined instance of the LF,
532 * as a constant, and the end result will be an optimal cast.)
533 *
534 * This erasure of cast types can be done with any use of
535 * reference types. It can also be done with whole method
536 * handles. Erasing a method handle might leave behind
537 * LF code that executes correctly for any MH of a given
538 * type, and load the required MH from the enclosing MH's data.
539 * Or, the erasure might even erase the expected MT.
540 *
541 * Also, for direct MHs, the MemberName of the target
542 * could be erased, and loaded from the containing direct MH.
543 * As a simple case, a LF for all int-valued non-static
544 * field getters would perform a cast on its input argument
545 * (to non-constant base type derived from the MemberName)
546 * and load an integer value from the input object
547 * (at a non-constant offset also derived from the MemberName).
548 * Such MN-erased LFs would be inlinable back to optimized
549 * code, whenever a constant enclosing DMH is available
550 * to supply a constant MN from its data.
551 *
552 * The main problem here is to keep LFs reasonably generic,
553 * while ensuring that hot spots will inline good instances.
554 * "Reasonably generic" means that we don't end up with
555 * repeated versions of bytecode or machine code that do
556 * not differ in their optimized form. Repeated versions
557 * of machine would have the undesirable overheads of
558 * (a) redundant compilation work and (b) extra I$ pressure.
559 * To control repeated versions, we need to be ready to
560 * erase details from LFs and move them into MH data,
561 * whevener those details are not relevant to significant
562 * optimization. "Significant" means optimization of
563 * code that is actually hot.
564 *
565 * Achieving this may require dynamic splitting of MHs, by replacing
566 * a generic LF with a more specialized one, on the same MH,
567 * if (a) the MH is frequently executed and (b) the MH cannot
568 * be inlined into a containing caller, such as an invokedynamic.
569 *
570 * Compiled LFs that are no longer used should be GC-able.
571 * If they contain non-BCP references, they should be properly
572 * interlinked with the class loader(s) that their embedded types
573 * depend on. This probably means that reusable compiled LFs
574 * will be tabulated (indexed) on relevant class loaders,
575 * or else that the tables that cache them will have weak links.
576 */
577
578 /**
579 * Make this LF directly executable, as part of a MethodHandle.
580 * Invariant: Every MH which is invoked must prepare its LF
581 * before invocation.
582 * (In principle, the JVM could do this very lazily,
583 * as a sort of pre-invocation linkage step.)
584 */
585 public void prepare() {
586 if (COMPILE_THRESHOLD == 0) {
587 compileToBytecode();
588 }
589 if (this.vmentry != null) {
590 // already prepared (e.g., a primitive DMH invoker form)
591 return;
592 }
593 LambdaForm prep = getPreparedForm(basicTypeSignature());
594 this.vmentry = prep.vmentry;
595 // TO DO: Maybe add invokeGeneric, invokeWithArguments
596 }
597
598 /** Generate optimizable bytecode for this form. */
599 MemberName compileToBytecode() {
600 MethodType invokerType = methodType();
601 assert(vmentry == null || vmentry.getMethodType().basicType().equals(invokerType));
602 if (vmentry != null && isCompiled) {
603 return vmentry; // already compiled somehow
604 }
605 try {
606 vmentry = InvokerBytecodeGenerator.generateCustomizedCode(this, invokerType);
607 if (TRACE_INTERPRETER)
608 traceInterpreter("compileToBytecode", this);
609 isCompiled = true;
610 return vmentry;
611 } catch (Error | Exception ex) {
612 throw newInternalError(this.toString(), ex);
613 }
614 }
615
616 private static void computeInitialPreparedForms() {
617 // Find all predefined invokers and associate them with canonical empty lambda forms.
618 for (MemberName m : MemberName.getFactory().getMethods(LambdaForm.class, false, null, null, null)) {
619 if (!m.isStatic() || !m.isPackage()) continue;
620 MethodType mt = m.getMethodType();
621 if (mt.parameterCount() > 0 &&
622 mt.parameterType(0) == MethodHandle.class &&
623 m.getName().startsWith("interpret_")) {
624 String sig = basicTypeSignature(mt);
625 assert(m.getName().equals("interpret" + sig.substring(sig.indexOf('_'))));
626 LambdaForm form = new LambdaForm(sig);
627 form.vmentry = m;
628 form = mt.form().setCachedLambdaForm(MethodTypeForm.LF_INTERPRET, form);
629 }
630 }
631 }
632
633 // Set this false to disable use of the interpret_L methods defined in this file.
634 private static final boolean USE_PREDEFINED_INTERPRET_METHODS = true;
635
636 // The following are predefined exact invokers. The system must build
637 // a separate invoker for each distinct signature.
638 static Object interpret_L(MethodHandle mh) throws Throwable {
639 Object[] av = {mh};
640 String sig = null;
641 assert(argumentTypesMatch(sig = "L_L", av));
642 Object res = mh.form.interpretWithArguments(av);
643 assert(returnTypesMatch(sig, av, res));
644 return res;
645 }
646 static Object interpret_L(MethodHandle mh, Object x1) throws Throwable {
647 Object[] av = {mh, x1};
648 String sig = null;
649 assert(argumentTypesMatch(sig = "LL_L", av));
650 Object res = mh.form.interpretWithArguments(av);
651 assert(returnTypesMatch(sig, av, res));
652 return res;
653 }
654 static Object interpret_L(MethodHandle mh, Object x1, Object x2) throws Throwable {
655 Object[] av = {mh, x1, x2};
656 String sig = null;
657 assert(argumentTypesMatch(sig = "LLL_L", av));
658 Object res = mh.form.interpretWithArguments(av);
659 assert(returnTypesMatch(sig, av, res));
660 return res;
661 }
662 private static LambdaForm getPreparedForm(String sig) {
663 MethodType mtype = signatureType(sig);
664 LambdaForm prep = mtype.form().cachedLambdaForm(MethodTypeForm.LF_INTERPRET);
665 if (prep != null) return prep;
666 assert(isValidSignature(sig));
667 prep = new LambdaForm(sig);
668 prep.vmentry = InvokerBytecodeGenerator.generateLambdaFormInterpreterEntryPoint(sig);
669 return mtype.form().setCachedLambdaForm(MethodTypeForm.LF_INTERPRET, prep);
670 }
671
672 // The next few routines are called only from assert expressions
673 // They verify that the built-in invokers process the correct raw data types.
674 private static boolean argumentTypesMatch(String sig, Object[] av) {
675 int arity = signatureArity(sig);
676 assert(av.length == arity) : "av.length == arity: av.length=" + av.length + ", arity=" + arity;
677 assert(av[0] instanceof MethodHandle) : "av[0] not instace of MethodHandle: " + av[0];
678 MethodHandle mh = (MethodHandle) av[0];
679 MethodType mt = mh.type();
680 assert(mt.parameterCount() == arity-1);
681 for (int i = 0; i < av.length; i++) {
682 Class<?> pt = (i == 0 ? MethodHandle.class : mt.parameterType(i-1));
683 assert(valueMatches(basicType(sig.charAt(i)), pt, av[i]));
684 }
685 return true;
686 }
687 private static boolean valueMatches(BasicType tc, Class<?> type, Object x) {
688 // The following line is needed because (...)void method handles can use non-void invokers
689 if (type == void.class) tc = V_TYPE; // can drop any kind of value
690 assert tc == basicType(type) : tc + " == basicType(" + type + ")=" + basicType(type);
691 switch (tc) {
692 case I_TYPE: assert checkInt(type, x) : "checkInt(" + type + "," + x +")"; break;
693 case J_TYPE: assert x instanceof Long : "instanceof Long: " + x; break;
694 case F_TYPE: assert x instanceof Float : "instanceof Float: " + x; break;
695 case D_TYPE: assert x instanceof Double : "instanceof Double: " + x; break;
696 case L_TYPE: assert checkRef(type, x) : "checkRef(" + type + "," + x + ")"; break;
697 case V_TYPE: break; // allow anything here; will be dropped
698 default: assert(false);
699 }
700 return true;
701 }
702 private static boolean returnTypesMatch(String sig, Object[] av, Object res) {
703 MethodHandle mh = (MethodHandle) av[0];
704 return valueMatches(signatureReturn(sig), mh.type().returnType(), res);
705 }
706 private static boolean checkInt(Class<?> type, Object x) {
707 assert(x instanceof Integer);
708 if (type == int.class) return true;
709 Wrapper w = Wrapper.forBasicType(type);
710 assert(w.isSubwordOrInt());
711 Object x1 = Wrapper.INT.wrap(w.wrap(x));
712 return x.equals(x1);
713 }
714 private static boolean checkRef(Class<?> type, Object x) {
715 assert(!type.isPrimitive());
716 if (x == null) return true;
717 if (type.isInterface()) return true;
718 return type.isInstance(x);
719 }
720
721 /** If the invocation count hits the threshold we spin bytecodes and call that subsequently. */
722 private static final int COMPILE_THRESHOLD;
723 static {
724 COMPILE_THRESHOLD = Math.max(-1, MethodHandleStatics.COMPILE_THRESHOLD);
725 }
726 private int invocationCounter = 0;
727
728 @Hidden
729 @DontInline
730 /** Interpretively invoke this form on the given arguments. */
731 Object interpretWithArguments(Object... argumentValues) throws Throwable {
732 if (TRACE_INTERPRETER)
733 return interpretWithArgumentsTracing(argumentValues);
734 checkInvocationCounter();
735 assert(arityCheck(argumentValues));
736 Object[] values = Arrays.copyOf(argumentValues, names.length);
737 for (int i = argumentValues.length; i < values.length; i++) {
738 values[i] = interpretName(names[i], values);
739 }
740 Object rv = (result < 0) ? null : values[result];
741 assert(resultCheck(argumentValues, rv));
742 return rv;
743 }
744
745 @Hidden
746 @DontInline
747 /** Evaluate a single Name within this form, applying its function to its arguments. */
748 Object interpretName(Name name, Object[] values) throws Throwable {
749 if (TRACE_INTERPRETER)
750 traceInterpreter("| interpretName", name.debugString(), (Object[]) null);
751 Object[] arguments = Arrays.copyOf(name.arguments, name.arguments.length, Object[].class);
752 for (int i = 0; i < arguments.length; i++) {
753 Object a = arguments[i];
754 if (a instanceof Name) {
755 int i2 = ((Name)a).index();
756 assert(names[i2] == a);
757 a = values[i2];
758 arguments[i] = a;
759 }
760 }
761 return name.function.invokeWithArguments(arguments);
762 }
763
764 private void checkInvocationCounter() {
765 if (COMPILE_THRESHOLD != 0 &&
766 invocationCounter < COMPILE_THRESHOLD) {
767 invocationCounter++; // benign race
768 if (invocationCounter >= COMPILE_THRESHOLD) {
769 // Replace vmentry with a bytecode version of this LF.
770 compileToBytecode();
771 }
772 }
773 }
774 Object interpretWithArgumentsTracing(Object... argumentValues) throws Throwable {
775 traceInterpreter("[ interpretWithArguments", this, argumentValues);
776 if (invocationCounter < COMPILE_THRESHOLD) {
777 int ctr = invocationCounter++; // benign race
778 traceInterpreter("| invocationCounter", ctr);
779 if (invocationCounter >= COMPILE_THRESHOLD) {
780 compileToBytecode();
781 }
782 }
783 Object rval;
784 try {
785 assert(arityCheck(argumentValues));
786 Object[] values = Arrays.copyOf(argumentValues, names.length);
787 for (int i = argumentValues.length; i < values.length; i++) {
788 values[i] = interpretName(names[i], values);
789 }
790 rval = (result < 0) ? null : values[result];
791 } catch (Throwable ex) {
792 traceInterpreter("] throw =>", ex);
793 throw ex;
794 }
795 traceInterpreter("] return =>", rval);
796 return rval;
797 }
798
799 //** This transform is applied (statically) to every name.function. */
800 /*
801 private static MethodHandle eraseSubwordTypes(MethodHandle mh) {
802 MethodType mt = mh.type();
803 if (mt.hasPrimitives()) {
804 mt = mt.changeReturnType(eraseSubwordType(mt.returnType()));
805 for (int i = 0; i < mt.parameterCount(); i++) {
806 mt = mt.changeParameterType(i, eraseSubwordType(mt.parameterType(i)));
807 }
808 mh = MethodHandles.explicitCastArguments(mh, mt);
809 }
810 return mh;
811 }
812 private static Class<?> eraseSubwordType(Class<?> type) {
813 if (!type.isPrimitive()) return type;
814 if (type == int.class) return type;
815 Wrapper w = Wrapper.forPrimitiveType(type);
816 if (w.isSubwordOrInt()) return int.class;
817 return type;
818 }
819 */
820
821 static void traceInterpreter(String event, Object obj, Object... args) {
822 if (TRACE_INTERPRETER) {
823 System.out.println("LFI: "+event+" "+(obj != null ? obj : "")+(args != null && args.length != 0 ? Arrays.asList(args) : ""));
824 }
825 }
826 static void traceInterpreter(String event, Object obj) {
827 traceInterpreter(event, obj, (Object[])null);
828 }
829 private boolean arityCheck(Object[] argumentValues) {
830 assert(argumentValues.length == arity) : arity+"!="+Arrays.asList(argumentValues)+".length";
831 // also check that the leading (receiver) argument is somehow bound to this LF:
832 assert(argumentValues[0] instanceof MethodHandle) : "not MH: " + argumentValues[0];
833 MethodHandle mh = (MethodHandle) argumentValues[0];
834 assert(mh.internalForm() == this);
835 // note: argument #0 could also be an interface wrapper, in the future
836 argumentTypesMatch(basicTypeSignature(), argumentValues);
837 return true;
838 }
839 private boolean resultCheck(Object[] argumentValues, Object result) {
840 MethodHandle mh = (MethodHandle) argumentValues[0];
841 MethodType mt = mh.type();
842 assert(valueMatches(returnType(), mt.returnType(), result));
843 return true;
844 }
845
846 private boolean isEmpty() {
847 if (result < 0)
848 return (names.length == arity);
849 else if (result == arity && names.length == arity + 1)
850 return names[arity].isConstantZero();
851 else
852 return false;
853 }
854
855 public String toString() {
856 StringBuilder buf = new StringBuilder(debugName+"=Lambda(");
857 for (int i = 0; i < names.length; i++) {
858 if (i == arity) buf.append(")=>{");
859 Name n = names[i];
860 if (i >= arity) buf.append("\n ");
861 buf.append(n.paramString());
862 if (i < arity) {
863 if (i+1 < arity) buf.append(",");
864 continue;
865 }
866 buf.append("=").append(n.exprString());
867 buf.append(";");
868 }
869 if (arity == names.length) buf.append(")=>{");
870 buf.append(result < 0 ? "void" : names[result]).append("}");
871 if (TRACE_INTERPRETER) {
872 // Extra verbosity:
873 buf.append(":").append(basicTypeSignature());
874 buf.append("/").append(vmentry);
875 }
876 return buf.toString();
877 }
878
879 @Override
880 public boolean equals(Object obj) {
881 return obj instanceof LambdaForm && equals((LambdaForm)obj);
882 }
883 public boolean equals(LambdaForm that) {
884 if (this.result != that.result) return false;
885 return Arrays.equals(this.names, that.names);
886 }
887 public int hashCode() {
888 return result + 31 * Arrays.hashCode(names);
889 }
890
891 LambdaForm bind(int namePos, BoundMethodHandle.SpeciesData oldData) {
892 Name name = names[namePos];
893 BoundMethodHandle.SpeciesData newData = oldData.extendWith(name.type);
894 return bind(name, new Name(newData.getterFunction(oldData.fieldCount()), names[0]), oldData, newData);
895 }
896 LambdaForm bind(Name name, Name binding,
897 BoundMethodHandle.SpeciesData oldData,
898 BoundMethodHandle.SpeciesData newData) {
899 int pos = name.index;
900 assert(name.isParam());
901 assert(!binding.isParam());
902 assert(name.type == binding.type);
903 assert(0 <= pos && pos < arity && names[pos] == name);
904 assert(binding.function.memberDeclaringClassOrNull() == newData.fieldHolder());
905 assert(oldData.getterFunctions().length == newData.getterFunctions().length-1);
906 if (bindCache != null) {
907 LambdaForm form = bindCache[pos];
908 if (form != null) {
909 assert(form.contains(binding)) : "form << " + form + " >> does not contain binding << " + binding + " >>";
910 return form;
911 }
912 } else {
913 bindCache = new LambdaForm[arity];
914 }
915 assert(nameRefsAreLegal());
916 int arity2 = arity-1;
917 Name[] names2 = names.clone();
918 names2[pos] = binding; // we might move this in a moment
919
920 // The newly created LF will run with a different BMH.
921 // Switch over any pre-existing BMH field references to the new BMH class.
922 int firstOldRef = -1;
923 for (int i = 0; i < names2.length; i++) {
924 Name n = names[i];
925 if (n.function != null &&
926 n.function.memberDeclaringClassOrNull() == oldData.fieldHolder()) {
927 MethodHandle oldGetter = n.function.resolvedHandle;
928 MethodHandle newGetter = null;
929 for (int j = 0; j < oldData.getterHandles().length; j++) {
930 if (oldGetter == oldData.getterHandles()[j])
931 newGetter = newData.getterHandles()[j];
932 }
933 if (newGetter != null) {
934 if (firstOldRef < 0) firstOldRef = i;
935 Name n2 = new Name(newGetter, n.arguments);
936 names2[i] = n2;
937 }
938 }
939 }
940
941 // Walk over the new list of names once, in forward order.
942 // Replace references to 'name' with 'binding'.
943 // Replace data structure references to the old BMH species with the new.
944 // This might cause a ripple effect, but it will settle in one pass.
945 assert(firstOldRef < 0 || firstOldRef > pos);
946 for (int i = pos+1; i < names2.length; i++) {
947 if (i <= arity2) continue;
948 names2[i] = names2[i].replaceNames(names, names2, pos, i);
949 }
950
951 // (a0, a1, name=a2, a3, a4) => (a0, a1, a3, a4, binding)
952 int insPos = pos;
953 for (; insPos+1 < names2.length; insPos++) {
954 Name n = names2[insPos+1];
955 if (n.isParam()) {
956 names2[insPos] = n;
957 } else {
958 break;
959 }
960 }
961 names2[insPos] = binding;
962
963 // Since we moved some stuff, maybe update the result reference:
964 int result2 = result;
965 if (result2 == pos)
966 result2 = insPos;
967 else if (result2 > pos && result2 <= insPos)
968 result2 -= 1;
969
970 return bindCache[pos] = new LambdaForm(debugName, arity2, names2, result2);
971 }
972
973 boolean contains(Name name) {
974 int pos = name.index();
975 if (pos >= 0) {
976 return pos < names.length && name.equals(names[pos]);
977 }
978 for (int i = arity; i < names.length; i++) {
979 if (name.equals(names[i]))
980 return true;
981 }
982 return false;
983 }
984
985 LambdaForm addArguments(int pos, BasicType... types) {
986 // names array has MH in slot 0; skip it.
987 int argpos = pos + 1;
988 assert(argpos <= arity);
989 int length = names.length;
990 int inTypes = types.length;
991 Name[] names2 = Arrays.copyOf(names, length + inTypes);
992 int arity2 = arity + inTypes;
993 int result2 = result;
994 if (result2 >= argpos)
995 result2 += inTypes;
996 // Note: The LF constructor will rename names2[argpos...].
997 // Make space for new arguments (shift temporaries).
998 System.arraycopy(names, argpos, names2, argpos + inTypes, length - argpos);
999 for (int i = 0; i < inTypes; i++) {
1000 names2[argpos + i] = new Name(types[i]);
1001 }
1002 return new LambdaForm(debugName, arity2, names2, result2);
1003 }
1004
1005 LambdaForm addArguments(int pos, List<Class<?>> types) {
1006 return addArguments(pos, basicTypes(types));
1007 }
1008
1009 LambdaForm permuteArguments(int skip, int[] reorder, BasicType[] types) {
1010 // Note: When inArg = reorder[outArg], outArg is fed by a copy of inArg.
1011 // The types are the types of the new (incoming) arguments.
1012 int length = names.length;
1013 int inTypes = types.length;
1014 int outArgs = reorder.length;
1015 assert(skip+outArgs == arity);
1016 assert(permutedTypesMatch(reorder, types, names, skip));
1017 int pos = 0;
1018 // skip trivial first part of reordering:
1019 while (pos < outArgs && reorder[pos] == pos) pos += 1;
1020 Name[] names2 = new Name[length - outArgs + inTypes];
1021 System.arraycopy(names, 0, names2, 0, skip+pos);
1022 // copy the body:
1023 int bodyLength = length - arity;
1024 System.arraycopy(names, skip+outArgs, names2, skip+inTypes, bodyLength);
1025 int arity2 = names2.length - bodyLength;
1026 int result2 = result;
1027 if (result2 >= 0) {
1028 if (result2 < skip+outArgs) {
1029 // return the corresponding inArg
1030 result2 = reorder[result2-skip];
1031 } else {
1032 result2 = result2 - outArgs + inTypes;
1033 }
1034 }
1035 // rework names in the body:
1036 for (int j = pos; j < outArgs; j++) {
1037 Name n = names[skip+j];
1038 int i = reorder[j];
1039 // replace names[skip+j] by names2[skip+i]
1040 Name n2 = names2[skip+i];
1041 if (n2 == null)
1042 names2[skip+i] = n2 = new Name(types[i]);
1043 else
1044 assert(n2.type == types[i]);
1045 for (int k = arity2; k < names2.length; k++) {
1046 names2[k] = names2[k].replaceName(n, n2);
1047 }
1048 }
1049 // some names are unused, but must be filled in
1050 for (int i = skip+pos; i < arity2; i++) {
1051 if (names2[i] == null)
1052 names2[i] = argument(i, types[i - skip]);
1053 }
1054 for (int j = arity; j < names.length; j++) {
1055 int i = j - arity + arity2;
1056 // replace names2[i] by names[j]
1057 Name n = names[j];
1058 Name n2 = names2[i];
1059 if (n != n2) {
1060 for (int k = i+1; k < names2.length; k++) {
1061 names2[k] = names2[k].replaceName(n, n2);
1062 }
1063 }
1064 }
1065 return new LambdaForm(debugName, arity2, names2, result2);
1066 }
1067
1068 static boolean permutedTypesMatch(int[] reorder, BasicType[] types, Name[] names, int skip) {
1069 int inTypes = types.length;
1070 int outArgs = reorder.length;
1071 for (int i = 0; i < outArgs; i++) {
1072 assert(names[skip+i].isParam());
1073 assert(names[skip+i].type == types[reorder[i]]);
1074 }
1075 return true;
1076 }
1077
1078 static class NamedFunction {
1079 final MemberName member;
1080 @Stable MethodHandle resolvedHandle;
1081 @Stable MethodHandle invoker;
1082
1083 NamedFunction(MethodHandle resolvedHandle) {
1084 this(resolvedHandle.internalMemberName(), resolvedHandle);
1085 }
1086 NamedFunction(MemberName member, MethodHandle resolvedHandle) {
1087 this.member = member;
1088 this.resolvedHandle = resolvedHandle;
1089 // The following assert is almost always correct, but will fail for corner cases, such as PrivateInvokeTest.
1090 //assert(!isInvokeBasic());
1091 }
1092 NamedFunction(MethodType basicInvokerType) {
1093 assert(basicInvokerType == basicInvokerType.basicType()) : basicInvokerType;
1094 if (basicInvokerType.parameterSlotCount() < MethodType.MAX_MH_INVOKER_ARITY) {
1095 this.resolvedHandle = basicInvokerType.invokers().basicInvoker();
1096 this.member = resolvedHandle.internalMemberName();
1097 } else {
1098 // necessary to pass BigArityTest
1099 this.member = Invokers.invokeBasicMethod(basicInvokerType);
1100 }
1101 assert(isInvokeBasic());
1102 }
1103
1104 private boolean isInvokeBasic() {
1105 return member != null &&
1106 member.isMethodHandleInvoke() &&
1107 "invokeBasic".equals(member.getName());
1108 }
1109
1110 // The next 3 constructors are used to break circular dependencies on MH.invokeStatic, etc.
1111 // Any LambdaForm containing such a member is not interpretable.
1112 // This is OK, since all such LFs are prepared with special primitive vmentry points.
1113 // And even without the resolvedHandle, the name can still be compiled and optimized.
1114 NamedFunction(Method method) {
1115 this(new MemberName(method));
1116 }
1117 NamedFunction(Field field) {
1118 this(new MemberName(field));
1119 }
1120 NamedFunction(MemberName member) {
1121 this.member = member;
1122 this.resolvedHandle = null;
1123 }
1124
1125 MethodHandle resolvedHandle() {
1126 if (resolvedHandle == null) resolve();
1127 return resolvedHandle;
1128 }
1129
1130 void resolve() {
1131 resolvedHandle = DirectMethodHandle.make(member);
1132 }
1133
1134 @Override
1135 public boolean equals(Object other) {
1136 if (this == other) return true;
1137 if (other == null) return false;
1138 if (!(other instanceof NamedFunction)) return false;
1139 NamedFunction that = (NamedFunction) other;
1140 return this.member != null && this.member.equals(that.member);
1141 }
1142
1143 @Override
1144 public int hashCode() {
1145 if (member != null)
1146 return member.hashCode();
1147 return super.hashCode();
1148 }
1149
1150 // Put the predefined NamedFunction invokers into the table.
1151 static void initializeInvokers() {
1152 for (MemberName m : MemberName.getFactory().getMethods(NamedFunction.class, false, null, null, null)) {
1153 if (!m.isStatic() || !m.isPackage()) continue;
1154 MethodType type = m.getMethodType();
1155 if (type.equals(INVOKER_METHOD_TYPE) &&
1156 m.getName().startsWith("invoke_")) {
1157 String sig = m.getName().substring("invoke_".length());
1158 int arity = LambdaForm.signatureArity(sig);
1159 MethodType srcType = MethodType.genericMethodType(arity);
1160 if (LambdaForm.signatureReturn(sig) == V_TYPE)
1161 srcType = srcType.changeReturnType(void.class);
1162 MethodTypeForm typeForm = srcType.form();
1163 typeForm.setCachedMethodHandle(MethodTypeForm.MH_NF_INV, DirectMethodHandle.make(m));
1164 }
1165 }
1166 }
1167
1168 // The following are predefined NamedFunction invokers. The system must build
1169 // a separate invoker for each distinct signature.
1170 /** void return type invokers. */
1171 @Hidden
1172 static Object invoke__V(MethodHandle mh, Object[] a) throws Throwable {
1173 assert(arityCheck(0, void.class, mh, a));
1174 mh.invokeBasic();
1175 return null;
1176 }
1177 @Hidden
1178 static Object invoke_L_V(MethodHandle mh, Object[] a) throws Throwable {
1179 assert(arityCheck(1, void.class, mh, a));
1180 mh.invokeBasic(a[0]);
1181 return null;
1182 }
1183 @Hidden
1184 static Object invoke_LL_V(MethodHandle mh, Object[] a) throws Throwable {
1185 assert(arityCheck(2, void.class, mh, a));
1186 mh.invokeBasic(a[0], a[1]);
1187 return null;
1188 }
1189 @Hidden
1190 static Object invoke_LLL_V(MethodHandle mh, Object[] a) throws Throwable {
1191 assert(arityCheck(3, void.class, mh, a));
1192 mh.invokeBasic(a[0], a[1], a[2]);
1193 return null;
1194 }
1195 @Hidden
1196 static Object invoke_LLLL_V(MethodHandle mh, Object[] a) throws Throwable {
1197 assert(arityCheck(4, void.class, mh, a));
1198 mh.invokeBasic(a[0], a[1], a[2], a[3]);
1199 return null;
1200 }
1201 @Hidden
1202 static Object invoke_LLLLL_V(MethodHandle mh, Object[] a) throws Throwable {
1203 assert(arityCheck(5, void.class, mh, a));
1204 mh.invokeBasic(a[0], a[1], a[2], a[3], a[4]);
1205 return null;
1206 }
1207 /** Object return type invokers. */
1208 @Hidden
1209 static Object invoke__L(MethodHandle mh, Object[] a) throws Throwable {
1210 assert(arityCheck(0, mh, a));
1211 return mh.invokeBasic();
1212 }
1213 @Hidden
1214 static Object invoke_L_L(MethodHandle mh, Object[] a) throws Throwable {
1215 assert(arityCheck(1, mh, a));
1216 return mh.invokeBasic(a[0]);
1217 }
1218 @Hidden
1219 static Object invoke_LL_L(MethodHandle mh, Object[] a) throws Throwable {
1220 assert(arityCheck(2, mh, a));
1221 return mh.invokeBasic(a[0], a[1]);
1222 }
1223 @Hidden
1224 static Object invoke_LLL_L(MethodHandle mh, Object[] a) throws Throwable {
1225 assert(arityCheck(3, mh, a));
1226 return mh.invokeBasic(a[0], a[1], a[2]);
1227 }
1228 @Hidden
1229 static Object invoke_LLLL_L(MethodHandle mh, Object[] a) throws Throwable {
1230 assert(arityCheck(4, mh, a));
1231 return mh.invokeBasic(a[0], a[1], a[2], a[3]);
1232 }
1233 @Hidden
1234 static Object invoke_LLLLL_L(MethodHandle mh, Object[] a) throws Throwable {
1235 assert(arityCheck(5, mh, a));
1236 return mh.invokeBasic(a[0], a[1], a[2], a[3], a[4]);
1237 }
1238 private static boolean arityCheck(int arity, MethodHandle mh, Object[] a) {
1239 return arityCheck(arity, Object.class, mh, a);
1240 }
1241 private static boolean arityCheck(int arity, Class<?> rtype, MethodHandle mh, Object[] a) {
1242 assert(a.length == arity)
1243 : Arrays.asList(a.length, arity);
1244 assert(mh.type().basicType() == MethodType.genericMethodType(arity).changeReturnType(rtype))
1245 : Arrays.asList(mh, rtype, arity);
1246 MemberName member = mh.internalMemberName();
1247 if (member != null && member.getName().equals("invokeBasic") && member.isMethodHandleInvoke()) {
1248 assert(arity > 0);
1249 assert(a[0] instanceof MethodHandle);
1250 MethodHandle mh2 = (MethodHandle) a[0];
1251 assert(mh2.type().basicType() == MethodType.genericMethodType(arity-1).changeReturnType(rtype))
1252 : Arrays.asList(member, mh2, rtype, arity);
1253 }
1254 return true;
1255 }
1256
1257 static final MethodType INVOKER_METHOD_TYPE =
1258 MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1259
1260 private static MethodHandle computeInvoker(MethodTypeForm typeForm) {
1261 typeForm = typeForm.basicType().form(); // normalize to basic type
1262 MethodHandle mh = typeForm.cachedMethodHandle(MethodTypeForm.MH_NF_INV);
1263 if (mh != null) return mh;
1264 MemberName invoker = InvokerBytecodeGenerator.generateNamedFunctionInvoker(typeForm); // this could take a while
1265 mh = DirectMethodHandle.make(invoker);
1266 MethodHandle mh2 = typeForm.cachedMethodHandle(MethodTypeForm.MH_NF_INV);
1267 if (mh2 != null) return mh2; // benign race
1268 if (!mh.type().equals(INVOKER_METHOD_TYPE))
1269 throw newInternalError(mh.debugString());
1270 return typeForm.setCachedMethodHandle(MethodTypeForm.MH_NF_INV, mh);
1271 }
1272
1273 @Hidden
1274 Object invokeWithArguments(Object... arguments) throws Throwable {
1275 // If we have a cached invoker, call it right away.
1276 // NOTE: The invoker always returns a reference value.
1277 if (TRACE_INTERPRETER) return invokeWithArgumentsTracing(arguments);
1278 assert(checkArgumentTypes(arguments, methodType()));
1279 return invoker().invokeBasic(resolvedHandle(), arguments);
1280 }
1281
1282 @Hidden
1283 Object invokeWithArgumentsTracing(Object[] arguments) throws Throwable {
1284 Object rval;
1285 try {
1286 traceInterpreter("[ call", this, arguments);
1287 if (invoker == null) {
1288 traceInterpreter("| getInvoker", this);
1289 invoker();
1290 }
1291 if (resolvedHandle == null) {
1292 traceInterpreter("| resolve", this);
1293 resolvedHandle();
1294 }
1295 assert(checkArgumentTypes(arguments, methodType()));
1296 rval = invoker().invokeBasic(resolvedHandle(), arguments);
1297 } catch (Throwable ex) {
1298 traceInterpreter("] throw =>", ex);
1299 throw ex;
1300 }
1301 traceInterpreter("] return =>", rval);
1302 return rval;
1303 }
1304
1305 private MethodHandle invoker() {
1306 if (invoker != null) return invoker;
1307 // Get an invoker and cache it.
1308 return invoker = computeInvoker(methodType().form());
1309 }
1310
1311 private static boolean checkArgumentTypes(Object[] arguments, MethodType methodType) {
1312 if (true) return true; // FIXME
1313 MethodType dstType = methodType.form().erasedType();
1314 MethodType srcType = dstType.basicType().wrap();
1315 Class<?>[] ptypes = new Class<?>[arguments.length];
1316 for (int i = 0; i < arguments.length; i++) {
1317 Object arg = arguments[i];
1318 Class<?> ptype = arg == null ? Object.class : arg.getClass();
1319 // If the dest. type is a primitive we keep the
1320 // argument type.
1321 ptypes[i] = dstType.parameterType(i).isPrimitive() ? ptype : Object.class;
1322 }
1323 MethodType argType = MethodType.methodType(srcType.returnType(), ptypes).wrap();
1324 assert(argType.isConvertibleTo(srcType)) : "wrong argument types: cannot convert " + argType + " to " + srcType;
1325 return true;
1326 }
1327
1328 MethodType methodType() {
1329 if (resolvedHandle != null)
1330 return resolvedHandle.type();
1331 else
1332 // only for certain internal LFs during bootstrapping
1333 return member.getInvocationType();
1334 }
1335
1336 MemberName member() {
1337 assert(assertMemberIsConsistent());
1338 return member;
1339 }
1340
1341 // Called only from assert.
1342 private boolean assertMemberIsConsistent() {
1343 if (resolvedHandle instanceof DirectMethodHandle) {
1344 MemberName m = resolvedHandle.internalMemberName();
1345 assert(m.equals(member));
1346 }
1347 return true;
1348 }
1349
1350 Class<?> memberDeclaringClassOrNull() {
1351 return (member == null) ? null : member.getDeclaringClass();
1352 }
1353
1354 BasicType returnType() {
1355 return basicType(methodType().returnType());
1356 }
1357
1358 BasicType parameterType(int n) {
1359 return basicType(methodType().parameterType(n));
1360 }
1361
1362 int arity() {
1363 return methodType().parameterCount();
1364 }
1365
1366 public String toString() {
1367 if (member == null) return String.valueOf(resolvedHandle);
1368 return member.getDeclaringClass().getSimpleName()+"."+member.getName();
1369 }
1370
1371 public boolean isIdentity() {
1372 return this.equals(identity(returnType()));
1373 }
1374
1375 public boolean isConstantZero() {
1376 return this.equals(constantZero(returnType()));
1377 }
1378
1379 public MethodHandleImpl.Intrinsic intrinsicName() {
1380 return resolvedHandle == null ? MethodHandleImpl.Intrinsic.NONE
1381 : resolvedHandle.intrinsicName();
1382 }
1383 }
1384
1385 public static String basicTypeSignature(MethodType type) {
1386 char[] sig = new char[type.parameterCount() + 2];
1387 int sigp = 0;
1388 for (Class<?> pt : type.parameterList()) {
1389 sig[sigp++] = basicTypeChar(pt);
1390 }
1391 sig[sigp++] = '_';
1392 sig[sigp++] = basicTypeChar(type.returnType());
1393 assert(sigp == sig.length);
1394 return String.valueOf(sig);
1395 }
1396 public static String shortenSignature(String signature) {
1397 // Hack to make signatures more readable when they show up in method names.
1398 final int NO_CHAR = -1, MIN_RUN = 3;
1399 int c0, c1 = NO_CHAR, c1reps = 0;
1400 StringBuilder buf = null;
1401 int len = signature.length();
1402 if (len < MIN_RUN) return signature;
1403 for (int i = 0; i <= len; i++) {
1404 // shift in the next char:
1405 c0 = c1; c1 = (i == len ? NO_CHAR : signature.charAt(i));
1406 if (c1 == c0) { ++c1reps; continue; }
1407 // shift in the next count:
1408 int c0reps = c1reps; c1reps = 1;
1409 // end of a character run
1410 if (c0reps < MIN_RUN) {
1411 if (buf != null) {
1412 while (--c0reps >= 0)
1413 buf.append((char)c0);
1414 }
1415 continue;
1416 }
1417 // found three or more in a row
1418 if (buf == null)
1419 buf = new StringBuilder().append(signature, 0, i - c0reps);
1420 buf.append((char)c0).append(c0reps);
1421 }
1422 return (buf == null) ? signature : buf.toString();
1423 }
1424
1425 static final class Name {
1426 final BasicType type;
1427 private short index;
1428 final NamedFunction function;
1429 final Object constraint; // additional type information, if not null
1430 @Stable final Object[] arguments;
1431
1432 private Name(int index, BasicType type, NamedFunction function, Object[] arguments) {
1433 this.index = (short)index;
1434 this.type = type;
1435 this.function = function;
1436 this.arguments = arguments;
1437 this.constraint = null;
1438 assert(this.index == index);
1439 }
1440 private Name(Name that, Object constraint) {
1441 this.index = that.index;
1442 this.type = that.type;
1443 this.function = that.function;
1444 this.arguments = that.arguments;
1445 this.constraint = constraint;
1446 assert(constraint == null || isParam()); // only params have constraints
1447 assert(constraint == null || constraint instanceof BoundMethodHandle.SpeciesData || constraint instanceof Class);
1448 }
1449 Name(MethodHandle function, Object... arguments) {
1450 this(new NamedFunction(function), arguments);
1451 }
1452 Name(MethodType functionType, Object... arguments) {
1453 this(new NamedFunction(functionType), arguments);
1454 assert(arguments[0] instanceof Name && ((Name)arguments[0]).type == L_TYPE);
1455 }
1456 Name(MemberName function, Object... arguments) {
1457 this(new NamedFunction(function), arguments);
1458 }
1459 Name(NamedFunction function, Object... arguments) {
1460 this(-1, function.returnType(), function, arguments = Arrays.copyOf(arguments, arguments.length, Object[].class));
1461 assert(arguments.length == function.arity()) : "arity mismatch: arguments.length=" + arguments.length + " == function.arity()=" + function.arity() + " in " + debugString();
1462 for (int i = 0; i < arguments.length; i++)
1463 assert(typesMatch(function.parameterType(i), arguments[i])) : "types don't match: function.parameterType(" + i + ")=" + function.parameterType(i) + ", arguments[" + i + "]=" + arguments[i] + " in " + debugString();
1464 }
1465 /** Create a raw parameter of the given type, with an expected index. */
1466 Name(int index, BasicType type) {
1467 this(index, type, null, null);
1468 }
1469 /** Create a raw parameter of the given type. */
1470 Name(BasicType type) { this(-1, type); }
1471
1472 BasicType type() { return type; }
1473 int index() { return index; }
1474 boolean initIndex(int i) {
1475 if (index != i) {
1476 if (index != -1) return false;
1477 index = (short)i;
1478 }
1479 return true;
1480 }
1481 char typeChar() {
1482 return type.btChar;
1483 }
1484
1485 void resolve() {
1486 if (function != null)
1487 function.resolve();
1488 }
1489
1490 Name newIndex(int i) {
1491 if (initIndex(i)) return this;
1492 return cloneWithIndex(i);
1493 }
1494 Name cloneWithIndex(int i) {
1495 Object[] newArguments = (arguments == null) ? null : arguments.clone();
1496 return new Name(i, type, function, newArguments).withConstraint(constraint);
1497 }
1498 Name withConstraint(Object constraint) {
1499 if (constraint == this.constraint) return this;
1500 return new Name(this, constraint);
1501 }
1502 Name replaceName(Name oldName, Name newName) { // FIXME: use replaceNames uniformly
1503 if (oldName == newName) return this;
1504 @SuppressWarnings("LocalVariableHidesMemberVariable")
1505 Object[] arguments = this.arguments;
1506 if (arguments == null) return this;
1507 boolean replaced = false;
1508 for (int j = 0; j < arguments.length; j++) {
1509 if (arguments[j] == oldName) {
1510 if (!replaced) {
1511 replaced = true;
1512 arguments = arguments.clone();
1513 }
1514 arguments[j] = newName;
1515 }
1516 }
1517 if (!replaced) return this;
1518 return new Name(function, arguments);
1519 }
1520 /** In the arguments of this Name, replace oldNames[i] pairwise by newNames[i].
1521 * Limit such replacements to {@code start<=i<end}. Return possibly changed self.
1522 */
1523 Name replaceNames(Name[] oldNames, Name[] newNames, int start, int end) {
1524 if (start >= end) return this;
1525 @SuppressWarnings("LocalVariableHidesMemberVariable")
1526 Object[] arguments = this.arguments;
1527 boolean replaced = false;
1528 eachArg:
1529 for (int j = 0; j < arguments.length; j++) {
1530 if (arguments[j] instanceof Name) {
1531 Name n = (Name) arguments[j];
1532 int check = n.index;
1533 // harmless check to see if the thing is already in newNames:
1534 if (check >= 0 && check < newNames.length && n == newNames[check])
1535 continue eachArg;
1536 // n might not have the correct index: n != oldNames[n.index].
1537 for (int i = start; i < end; i++) {
1538 if (n == oldNames[i]) {
1539 if (n == newNames[i])
1540 continue eachArg;
1541 if (!replaced) {
1542 replaced = true;
1543 arguments = arguments.clone();
1544 }
1545 arguments[j] = newNames[i];
1546 continue eachArg;
1547 }
1548 }
1549 }
1550 }
1551 if (!replaced) return this;
1552 return new Name(function, arguments);
1553 }
1554 void internArguments() {
1555 @SuppressWarnings("LocalVariableHidesMemberVariable")
1556 Object[] arguments = this.arguments;
1557 for (int j = 0; j < arguments.length; j++) {
1558 if (arguments[j] instanceof Name) {
1559 Name n = (Name) arguments[j];
1560 if (n.isParam() && n.index < INTERNED_ARGUMENT_LIMIT)
1561 arguments[j] = internArgument(n);
1562 }
1563 }
1564 }
1565 boolean isParam() {
1566 return function == null;
1567 }
1568 boolean isConstantZero() {
1569 return !isParam() && arguments.length == 0 && function.isConstantZero();
1570 }
1571
1572 public String toString() {
1573 return (isParam()?"a":"t")+(index >= 0 ? index : System.identityHashCode(this))+":"+typeChar();
1574 }
1575 public String debugString() {
1576 String s = paramString();
1577 return (function == null) ? s : s + "=" + exprString();
1578 }
1579 public String paramString() {
1580 String s = toString();
1581 Object c = constraint;
1582 if (c == null)
1583 return s;
1584 if (c instanceof Class) c = ((Class<?>)c).getSimpleName();
1585 return s + "/" + c;
1586 }
1587 public String exprString() {
1588 if (function == null) return toString();
1589 StringBuilder buf = new StringBuilder(function.toString());
1590 buf.append("(");
1591 String cma = "";
1592 for (Object a : arguments) {
1593 buf.append(cma); cma = ",";
1594 if (a instanceof Name || a instanceof Integer)
1595 buf.append(a);
1596 else
1597 buf.append("(").append(a).append(")");
1598 }
1599 buf.append(")");
1600 return buf.toString();
1601 }
1602
1603 static boolean typesMatch(BasicType parameterType, Object object) {
1604 if (object instanceof Name) {
1605 return ((Name)object).type == parameterType;
1606 }
1607 switch (parameterType) {
1608 case I_TYPE: return object instanceof Integer;
1609 case J_TYPE: return object instanceof Long;
1610 case F_TYPE: return object instanceof Float;
1611 case D_TYPE: return object instanceof Double;
1612 }
1613 assert(parameterType == L_TYPE);
1614 return true;
1615 }
1616
1617 /** Return the index of the last occurrence of n in the argument array.
1618 * Return -1 if the name is not used.
1619 */
1620 int lastUseIndex(Name n) {
1621 if (arguments == null) return -1;
1622 for (int i = arguments.length; --i >= 0; ) {
1623 if (arguments[i] == n) return i;
1624 }
1625 return -1;
1626 }
1627
1628 /** Return the number of occurrences of n in the argument array.
1629 * Return 0 if the name is not used.
1630 */
1631 int useCount(Name n) {
1632 if (arguments == null) return 0;
1633 int count = 0;
1634 for (int i = arguments.length; --i >= 0; ) {
1635 if (arguments[i] == n) ++count;
1636 }
1637 return count;
1638 }
1639
1640 boolean contains(Name n) {
1641 return this == n || lastUseIndex(n) >= 0;
1642 }
1643
1644 public boolean equals(Name that) {
1645 if (this == that) return true;
1646 if (isParam())
1647 // each parameter is a unique atom
1648 return false; // this != that
1649 return
1650 //this.index == that.index &&
1651 this.type == that.type &&
1652 this.function.equals(that.function) &&
1653 Arrays.equals(this.arguments, that.arguments);
1654 }
1655 @Override
1656 public boolean equals(Object x) {
1657 return x instanceof Name && equals((Name)x);
1658 }
1659 @Override
1660 public int hashCode() {
1661 if (isParam())
1662 return index | (type.ordinal() << 8);
1663 return function.hashCode() ^ Arrays.hashCode(arguments);
1664 }
1665 }
1666
1667 /** Return the index of the last name which contains n as an argument.
1668 * Return -1 if the name is not used. Return names.length if it is the return value.
1669 */
1670 int lastUseIndex(Name n) {
1671 int ni = n.index, nmax = names.length;
1672 assert(names[ni] == n);
1673 if (result == ni) return nmax; // live all the way beyond the end
1674 for (int i = nmax; --i > ni; ) {
1675 if (names[i].lastUseIndex(n) >= 0)
1676 return i;
1677 }
1678 return -1;
1679 }
1680
1681 /** Return the number of times n is used as an argument or return value. */
1682 int useCount(Name n) {
1683 int ni = n.index, nmax = names.length;
1684 int end = lastUseIndex(n);
1685 if (end < 0) return 0;
1686 int count = 0;
1687 if (end == nmax) { count++; end--; }
1688 int beg = n.index() + 1;
1689 if (beg < arity) beg = arity;
1690 for (int i = beg; i <= end; i++) {
1691 count += names[i].useCount(n);
1692 }
1693 return count;
1694 }
1695
1696 static Name argument(int which, char type) {
1697 return argument(which, basicType(type));
1698 }
1699 static Name argument(int which, BasicType type) {
1700 if (which >= INTERNED_ARGUMENT_LIMIT)
1701 return new Name(which, type);
1702 return INTERNED_ARGUMENTS[type.ordinal()][which];
1703 }
1704 static Name internArgument(Name n) {
1705 assert(n.isParam()) : "not param: " + n;
1706 assert(n.index < INTERNED_ARGUMENT_LIMIT);
1707 if (n.constraint != null) return n;
1708 return argument(n.index, n.type);
1709 }
1710 static Name[] arguments(int extra, String types) {
1711 int length = types.length();
1712 Name[] names = new Name[length + extra];
1713 for (int i = 0; i < length; i++)
1714 names[i] = argument(i, types.charAt(i));
1715 return names;
1716 }
1717 static Name[] arguments(int extra, char... types) {
1718 int length = types.length;
1719 Name[] names = new Name[length + extra];
1720 for (int i = 0; i < length; i++)
1721 names[i] = argument(i, types[i]);
1722 return names;
1723 }
1724 static Name[] arguments(int extra, List<Class<?>> types) {
1725 int length = types.size();
1726 Name[] names = new Name[length + extra];
1727 for (int i = 0; i < length; i++)
1728 names[i] = argument(i, basicType(types.get(i)));
1729 return names;
1730 }
1731 static Name[] arguments(int extra, Class<?>... types) {
1732 int length = types.length;
1733 Name[] names = new Name[length + extra];
1734 for (int i = 0; i < length; i++)
1735 names[i] = argument(i, basicType(types[i]));
1736 return names;
1737 }
1738 static Name[] arguments(int extra, MethodType types) {
1739 int length = types.parameterCount();
1740 Name[] names = new Name[length + extra];
1741 for (int i = 0; i < length; i++)
1742 names[i] = argument(i, basicType(types.parameterType(i)));
1743 return names;
1744 }
1745 static final int INTERNED_ARGUMENT_LIMIT = 10;
1746 private static final Name[][] INTERNED_ARGUMENTS
1747 = new Name[ARG_TYPE_LIMIT][INTERNED_ARGUMENT_LIMIT];
1748 static {
1749 for (BasicType type : BasicType.ARG_TYPES) {
1750 int ord = type.ordinal();
1751 for (int i = 0; i < INTERNED_ARGUMENTS[ord].length; i++) {
1752 INTERNED_ARGUMENTS[ord][i] = new Name(i, type);
1753 }
1754 }
1755 }
1756
1757 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
1758
1759 static LambdaForm identityForm(BasicType type) {
1760 return LF_identityForm[type.ordinal()];
1761 }
1762 static LambdaForm zeroForm(BasicType type) {
1763 return LF_zeroForm[type.ordinal()];
1764 }
1765 static NamedFunction identity(BasicType type) {
1766 return NF_identity[type.ordinal()];
1767 }
1768 static NamedFunction constantZero(BasicType type) {
1769 return NF_zero[type.ordinal()];
1770 }
1771 private static final LambdaForm[] LF_identityForm = new LambdaForm[TYPE_LIMIT];
1772 private static final LambdaForm[] LF_zeroForm = new LambdaForm[TYPE_LIMIT];
1773 private static final NamedFunction[] NF_identity = new NamedFunction[TYPE_LIMIT];
1774 private static final NamedFunction[] NF_zero = new NamedFunction[TYPE_LIMIT];
1775 private static void createIdentityForms() {
1776 for (BasicType type : BasicType.ALL_TYPES) {
1777 int ord = type.ordinal();
1778 char btChar = type.basicTypeChar();
1779 boolean isVoid = (type == V_TYPE);
1780 Class<?> btClass = type.btClass;
1781 MethodType zeType = MethodType.methodType(btClass);
1782 MethodType idType = isVoid ? zeType : zeType.appendParameterTypes(btClass);
1783
1784 // Look up some symbolic names. It might not be necessary to have these,
1785 // but if we need to emit direct references to bytecodes, it helps.
1786 // Zero is built from a call to an identity function with a constant zero input.
1787 MemberName idMem = new MemberName(LambdaForm.class, "identity_"+btChar, idType, REF_invokeStatic);
1788 MemberName zeMem = new MemberName(LambdaForm.class, "zero_"+btChar, zeType, REF_invokeStatic);
1789 try {
1790 zeMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, zeMem, null, NoSuchMethodException.class);
1791 idMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, idMem, null, NoSuchMethodException.class);
1792 } catch (IllegalAccessException|NoSuchMethodException ex) {
1793 throw newInternalError(ex);
1794 }
1795
1796 NamedFunction idFun = new NamedFunction(idMem);
1797 LambdaForm idForm;
1798 if (isVoid) {
1799 Name[] idNames = new Name[] { argument(0, L_TYPE) };
1800 idForm = new LambdaForm(idMem.getName(), 1, idNames, VOID_RESULT);
1801 } else {
1802 Name[] idNames = new Name[] { argument(0, L_TYPE), argument(1, type) };
1803 idForm = new LambdaForm(idMem.getName(), 2, idNames, 1);
1804 }
1805 LF_identityForm[ord] = idForm;
1806 NF_identity[ord] = idFun;
1807
1808 NamedFunction zeFun = new NamedFunction(zeMem);
1809 LambdaForm zeForm;
1810 if (isVoid) {
1811 zeForm = idForm;
1812 } else {
1813 Object zeValue = Wrapper.forBasicType(btChar).zero();
1814 Name[] zeNames = new Name[] { argument(0, L_TYPE), new Name(idFun, zeValue) };
1815 zeForm = new LambdaForm(zeMem.getName(), 1, zeNames, 1);
1816 }
1817 LF_zeroForm[ord] = zeForm;
1818 NF_zero[ord] = zeFun;
1819
1820 assert(idFun.isIdentity());
1821 assert(zeFun.isConstantZero());
1822 assert(new Name(zeFun).isConstantZero());
1823 }
1824
1825 // Do this in a separate pass, so that SimpleMethodHandle.make can see the tables.
1826 for (BasicType type : BasicType.ALL_TYPES) {
1827 int ord = type.ordinal();
1828 NamedFunction idFun = NF_identity[ord];
1829 LambdaForm idForm = LF_identityForm[ord];
1830 MemberName idMem = idFun.member;
1831 idFun.resolvedHandle = SimpleMethodHandle.make(idMem.getInvocationType(), idForm);
1832
1833 NamedFunction zeFun = NF_zero[ord];
1834 LambdaForm zeForm = LF_zeroForm[ord];
1835 MemberName zeMem = zeFun.member;
1836 zeFun.resolvedHandle = SimpleMethodHandle.make(zeMem.getInvocationType(), zeForm);
1837
1838 assert(idFun.isIdentity());
1839 assert(zeFun.isConstantZero());
1840 assert(new Name(zeFun).isConstantZero());
1841 }
1842 }
1843
1844 // Avoid appealing to ValueConversions at bootstrap time:
1845 private static int identity_I(int x) { return x; }
1846 private static long identity_J(long x) { return x; }
1847 private static float identity_F(float x) { return x; }
1848 private static double identity_D(double x) { return x; }
1849 private static Object identity_L(Object x) { return x; }
1850 private static void identity_V() { return; } // same as zeroV, but that's OK
1851 private static int zero_I() { return 0; }
1852 private static long zero_J() { return 0; }
1853 private static float zero_F() { return 0; }
1854 private static double zero_D() { return 0; }
1855 private static Object zero_L() { return null; }
1856 private static void zero_V() { return; }
1857
1858 /**
1859 * Internal marker for byte-compiled LambdaForms.
1860 */
1861 /*non-public*/
1862 @Target(ElementType.METHOD)
1863 @Retention(RetentionPolicy.RUNTIME)
1864 @interface Compiled {
1865 }
1866
1867 /**
1868 * Internal marker for LambdaForm interpreter frames.
1869 */
1870 /*non-public*/
1871 @Target(ElementType.METHOD)
1872 @Retention(RetentionPolicy.RUNTIME)
1873 @interface Hidden {
1874 }
1875
1876 private static final HashMap<String,Integer> DEBUG_NAME_COUNTERS;
1877 static {
1878 if (debugEnabled())
1879 DEBUG_NAME_COUNTERS = new HashMap<>();
1880 else
1881 DEBUG_NAME_COUNTERS = null;
1882 }
1883
1884 // Put this last, so that previous static inits can run before.
1885 static {
1886 createIdentityForms();
1887 if (USE_PREDEFINED_INTERPRET_METHODS)
1888 computeInitialPreparedForms();
1889 NamedFunction.initializeInvokers();
1890 }
1891
1892 // The following hack is necessary in order to suppress TRACE_INTERPRETER
1893 // during execution of the static initializes of this class.
1894 // Turning on TRACE_INTERPRETER too early will cause
1895 // stack overflows and other misbehavior during attempts to trace events
1896 // that occur during LambdaForm.<clinit>.
1897 // Therefore, do not move this line higher in this file, and do not remove.
1898 private static final boolean TRACE_INTERPRETER = MethodHandleStatics.TRACE_INTERPRETER;
1899 }