1 /*
2 * Copyright (c) 1998, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "compiler/compileLog.hpp"
27 #include "interpreter/linkResolver.hpp"
28 #include "memory/universe.inline.hpp"
29 #include "oops/objArrayKlass.hpp"
30 #include "oops/valueArrayKlass.hpp"
31 #include "opto/addnode.hpp"
32 #include "opto/castnode.hpp"
33 #include "opto/memnode.hpp"
34 #include "opto/parse.hpp"
35 #include "opto/rootnode.hpp"
36 #include "opto/runtime.hpp"
37 #include "opto/subnode.hpp"
38 #include "opto/valuetypenode.hpp"
39 #include "runtime/deoptimization.hpp"
40 #include "runtime/handles.inline.hpp"
41
42 //=============================================================================
43 // Helper methods for _get* and _put* bytecodes
44 //=============================================================================
45 bool Parse::static_field_ok_in_clinit(ciField *field, ciMethod *method) {
46 // Could be the field_holder's <clinit> method, or <clinit> for a subklass.
47 // Better to check now than to Deoptimize as soon as we execute
48 assert( field->is_static(), "Only check if field is static");
49 // is_being_initialized() is too generous. It allows access to statics
50 // by threads that are not running the <clinit> before the <clinit> finishes.
51 // return field->holder()->is_being_initialized();
52
53 // The following restriction is correct but conservative.
54 // It is also desirable to allow compilation of methods called from <clinit>
55 // but this generated code will need to be made safe for execution by
56 // other threads, or the transition from interpreted to compiled code would
57 // need to be guarded.
58 ciInstanceKlass *field_holder = field->holder();
59
60 bool access_OK = false;
61 if (method->holder()->is_subclass_of(field_holder)) {
62 if (method->is_static()) {
63 if (method->name() == ciSymbol::class_initializer_name()) {
64 // OK to access static fields inside initializer
65 access_OK = true;
66 }
67 } else {
68 if (method->name() == ciSymbol::object_initializer_name()) {
69 // It's also OK to access static fields inside a constructor,
70 // because any thread calling the constructor must first have
71 // synchronized on the class by executing a '_new' bytecode.
72 access_OK = true;
73 }
74 }
75 }
76
77 return access_OK;
78
79 }
80
81
82 void Parse::do_field_access(bool is_get, bool is_field) {
83 bool will_link;
84 ciField* field = iter().get_field(will_link);
85 assert(will_link, "getfield: typeflow responsibility");
86
87 ciInstanceKlass* field_holder = field->holder();
88
89 if (is_field == field->is_static()) {
90 // Interpreter will throw java_lang_IncompatibleClassChangeError
91 // Check this before allowing <clinit> methods to access static fields
92 uncommon_trap(Deoptimization::Reason_unhandled,
93 Deoptimization::Action_none);
94 return;
95 }
96
97 if (!is_field && !field_holder->is_initialized()) {
98 if (!static_field_ok_in_clinit(field, method())) {
99 uncommon_trap(Deoptimization::Reason_uninitialized,
100 Deoptimization::Action_reinterpret,
101 NULL, "!static_field_ok_in_clinit");
102 return;
103 }
104 }
105
106 // Deoptimize on putfield writes to call site target field.
107 if (!is_get && field->is_call_site_target()) {
108 uncommon_trap(Deoptimization::Reason_unhandled,
109 Deoptimization::Action_reinterpret,
110 NULL, "put to call site target field");
111 return;
112 }
113
114 assert(field->will_link(method(), bc()), "getfield: typeflow responsibility");
115
116 // Note: We do not check for an unloaded field type here any more.
117
118 // Generate code for the object pointer.
119 Node* obj;
120 if (is_field) {
121 int obj_depth = is_get ? 0 : field->type()->size();
122 obj = null_check(peek(obj_depth));
123 // Compile-time detect of null-exception?
124 if (stopped()) return;
125
126 #ifdef ASSERT
127 const TypeInstPtr *tjp = TypeInstPtr::make(TypePtr::NotNull, iter().get_declared_field_holder());
128 assert(_gvn.type(obj)->higher_equal(tjp), "cast_up is no longer needed");
129 #endif
130
131 if (is_get) {
132 (void) pop(); // pop receiver before getting
133 do_get_xxx(obj, field, is_field);
134 } else {
135 do_put_xxx(obj, field, is_field);
136 (void) pop(); // pop receiver after putting
137 }
138 } else {
139 const TypeInstPtr* tip = TypeInstPtr::make(field_holder->java_mirror());
140 obj = _gvn.makecon(tip);
141 if (is_get) {
142 do_get_xxx(obj, field, is_field);
143 } else {
144 do_put_xxx(obj, field, is_field);
145 }
146 }
147 }
148
149 void Parse::do_vgetfield() {
150 // fixme null/top check?
151 bool will_link;
152 ciField* field = iter().get_field(will_link);
153 BasicType bt = field->layout_type();
154 ValueTypeNode* vt = pop()->as_ValueType();
155 Node* value = vt->field_value_by_offset(field->offset());
156 push_node(bt, value);
157 }
158
159 void Parse::do_get_xxx(Node* obj, ciField* field, bool is_field) {
160 BasicType bt = field->layout_type();
161
162 // Does this field have a constant value? If so, just push the value.
163 if (field->is_constant() &&
164 // Keep consistent with types found by ciTypeFlow: for an
165 // unloaded field type, ciTypeFlow::StateVector::do_getstatic()
166 // speculates the field is null. The code in the rest of this
167 // method does the same. We must not bypass it and use a non
168 // null constant here.
169 (bt != T_OBJECT || field->type()->is_loaded())) {
170 // final or stable field
171 Node* con = make_constant_from_field(field, obj);
172 if (con != NULL) {
173 push_node(field->layout_type(), con);
174 return;
175 }
176 }
177
178 ciType* field_klass = field->type();
179 bool is_vol = field->is_volatile();
180 // TODO change this when we support non-flattened value type fields that are non-static
181 bool flattened = (bt == T_VALUETYPE) && !field->is_static();
182
183 // Compute address and memory type.
184 int offset = field->offset_in_bytes();
185 const TypePtr* adr_type = C->alias_type(field)->adr_type();
186 Node *adr = basic_plus_adr(obj, obj, offset);
187
188 // Build the resultant type of the load
189 const Type *type;
190
191 bool must_assert_null = false;
192 if (bt == T_OBJECT || bt == T_VALUETYPE) {
193 if (!field->type()->is_loaded()) {
194 type = TypeInstPtr::BOTTOM;
195 must_assert_null = true;
196 } else if (field->is_static_constant()) {
197 // This can happen if the constant oop is non-perm.
198 ciObject* con = field->constant_value().as_object();
199 // Do not "join" in the previous type; it doesn't add value,
200 // and may yield a vacuous result if the field is of interface type.
201 if (con->is_null_object()) {
202 type = TypePtr::NULL_PTR;
203 } else {
204 type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
205 }
206 assert(type != NULL, "field singleton type must be consistent");
207 } else {
208 type = TypeOopPtr::make_from_klass(field_klass->as_klass());
209 if (bt == T_VALUETYPE && !flattened) {
210 // A non-flattened value type field may be NULL
211 bool maybe_null = true;
212 if (field->is_static()) {
213 // Check if static field is already initialized
214 ciInstance* mirror = field->holder()->java_mirror();
215 ciObject* val = mirror->field_value(field).as_object();
216 if (!val->is_null_object()) {
217 maybe_null = false;
218 }
219 }
220 if (maybe_null) {
221 type = type->is_valuetypeptr()->cast_to_ptr_type(TypePtr::BotPTR);
222 }
223 }
224 }
225 } else {
226 type = Type::get_const_basic_type(bt);
227 }
228 if (support_IRIW_for_not_multiple_copy_atomic_cpu && field->is_volatile()) {
229 insert_mem_bar(Op_MemBarVolatile); // StoreLoad barrier
230 }
231
232 // Build the load.
233 //
234 MemNode::MemOrd mo = is_vol ? MemNode::acquire : MemNode::unordered;
235 bool needs_atomic_access = is_vol || AlwaysAtomicAccesses;
236 Node* ld = NULL;
237 if (flattened) {
238 // Load flattened value type
239 ld = ValueTypeNode::make(_gvn, field_klass->as_value_klass(), map()->memory(), obj, obj, field->holder(), offset);
240 } else {
241 ld = make_load(NULL, adr, type, bt, adr_type, mo, LoadNode::DependsOnlyOnTest, needs_atomic_access);
242 }
243
244 // Adjust Java stack
245 if (type2size[bt] == 1)
246 push(ld);
247 else
248 push_pair(ld);
249
250 if (must_assert_null) {
251 // Do not take a trap here. It's possible that the program
252 // will never load the field's class, and will happily see
253 // null values in this field forever. Don't stumble into a
254 // trap for such a program, or we might get a long series
255 // of useless recompilations. (Or, we might load a class
256 // which should not be loaded.) If we ever see a non-null
257 // value, we will then trap and recompile. (The trap will
258 // not need to mention the class index, since the class will
259 // already have been loaded if we ever see a non-null value.)
260 // uncommon_trap(iter().get_field_signature_index());
261 if (PrintOpto && (Verbose || WizardMode)) {
262 method()->print_name(); tty->print_cr(" asserting nullness of field at bci: %d", bci());
263 }
264 if (C->log() != NULL) {
265 C->log()->elem("assert_null reason='field' klass='%d'",
266 C->log()->identify(field->type()));
267 }
268 // If there is going to be a trap, put it at the next bytecode:
269 set_bci(iter().next_bci());
270 null_assert(peek());
271 set_bci(iter().cur_bci()); // put it back
272 }
273
274 // If reference is volatile, prevent following memory ops from
275 // floating up past the volatile read. Also prevents commoning
276 // another volatile read.
277 if (field->is_volatile()) {
278 // Memory barrier includes bogus read of value to force load BEFORE membar
279 insert_mem_bar(Op_MemBarAcquire, ld);
280 }
281 }
282
283 void Parse::do_put_xxx(Node* obj, ciField* field, bool is_field) {
284 bool is_vol = field->is_volatile();
285 // If reference is volatile, prevent following memory ops from
286 // floating down past the volatile write. Also prevents commoning
287 // another volatile read.
288 if (is_vol) insert_mem_bar(Op_MemBarRelease);
289
290 // Compute address and memory type.
291 int offset = field->offset_in_bytes();
292 const TypePtr* adr_type = C->alias_type(field)->adr_type();
293 Node* adr = basic_plus_adr(obj, obj, offset);
294 BasicType bt = field->layout_type();
295 // Value to be stored
296 Node* val = type2size[bt] == 1 ? pop() : pop_pair();
297 // Round doubles before storing
298 if (bt == T_DOUBLE) val = dstore_rounding(val);
299
300 // Conservatively release stores of object references.
301 const MemNode::MemOrd mo =
302 is_vol ?
303 // Volatile fields need releasing stores.
304 MemNode::release :
305 // Non-volatile fields also need releasing stores if they hold an
306 // object reference, because the object reference might point to
307 // a freshly created object.
308 StoreNode::release_if_reference(bt);
309
310 // Store the value.
311 if (bt == T_OBJECT || bt == T_VALUETYPE) {
312 const TypeOopPtr* field_type;
313 if (!field->type()->is_loaded()) {
314 field_type = TypeInstPtr::BOTTOM;
315 } else {
316 field_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
317 }
318 if (bt == T_VALUETYPE && !field->is_static()) {
319 // Store flattened value type to non-static field
320 val->as_ValueType()->store(this, obj, obj, field->holder(), offset);
321 } else {
322 store_oop_to_object(control(), obj, adr, adr_type, val, field_type, bt, mo);
323 }
324 } else {
325 bool needs_atomic_access = is_vol || AlwaysAtomicAccesses;
326 store_to_memory(control(), adr, val, bt, adr_type, mo, needs_atomic_access);
327 }
328
329 // If reference is volatile, prevent following volatiles ops from
330 // floating up before the volatile write.
331 if (is_vol) {
332 // If not multiple copy atomic, we do the MemBarVolatile before the load.
333 if (!support_IRIW_for_not_multiple_copy_atomic_cpu) {
334 insert_mem_bar(Op_MemBarVolatile); // Use fat membar
335 }
336 // Remember we wrote a volatile field.
337 // For not multiple copy atomic cpu (ppc64) a barrier should be issued
338 // in constructors which have such stores. See do_exits() in parse1.cpp.
339 if (is_field) {
340 set_wrote_volatile(true);
341 }
342 }
343
344 if (is_field) {
345 set_wrote_fields(true);
346 }
347
348 // If the field is final, the rules of Java say we are in <init> or <clinit>.
349 // Note the presence of writes to final non-static fields, so that we
350 // can insert a memory barrier later on to keep the writes from floating
351 // out of the constructor.
352 // Any method can write a @Stable field; insert memory barriers after those also.
353 if (is_field && (field->is_final() || field->is_stable())) {
354 if (field->is_final()) {
355 set_wrote_final(true);
356 }
357 if (field->is_stable()) {
358 set_wrote_stable(true);
359 }
360
361 // Preserve allocation ptr to create precedent edge to it in membar
362 // generated on exit from constructor.
363 // Can't bind stable with its allocation, only record allocation for final field.
364 if (field->is_final() && AllocateNode::Ideal_allocation(obj, &_gvn) != NULL) {
365 set_alloc_with_final(obj);
366 }
367 }
368 }
369
370 //=============================================================================
371
372 void Parse::do_newarray() {
373 bool will_link;
374 ciKlass* klass = iter().get_klass(will_link);
375
376 // Uncommon Trap when class that array contains is not loaded
377 // we need the loaded class for the rest of graph; do not
378 // initialize the container class (see Java spec)!!!
379 assert(will_link, "newarray: typeflow responsibility");
380
381 ciArrayKlass* array_klass = ciArrayKlass::make(klass);
382 // Check that array_klass object is loaded
383 if (!array_klass->is_loaded()) {
384 // Generate uncommon_trap for unloaded array_class
385 uncommon_trap(Deoptimization::Reason_unloaded,
386 Deoptimization::Action_reinterpret,
387 array_klass);
388 return;
389 } else if (array_klass->element_klass() != NULL &&
390 array_klass->element_klass()->is_valuetype() &&
391 !array_klass->element_klass()->as_value_klass()->is_initialized()) {
392 uncommon_trap(Deoptimization::Reason_uninitialized,
393 Deoptimization::Action_reinterpret,
394 NULL);
395 return;
396 }
397
398 kill_dead_locals();
399
400 const TypeKlassPtr* array_klass_type = TypeKlassPtr::make(array_klass);
401 Node* count_val = pop();
402 Node* obj = new_array(makecon(array_klass_type), count_val, 1);
403 push(obj);
404 }
405
406
407 void Parse::do_newarray(BasicType elem_type) {
408 kill_dead_locals();
409
410 Node* count_val = pop();
411 const TypeKlassPtr* array_klass = TypeKlassPtr::make(ciTypeArrayKlass::make(elem_type));
412 Node* obj = new_array(makecon(array_klass), count_val, 1);
413 // Push resultant oop onto stack
414 push(obj);
415 }
416
417 // Expand simple expressions like new int[3][5] and new Object[2][nonConLen].
418 // Also handle the degenerate 1-dimensional case of anewarray.
419 Node* Parse::expand_multianewarray(ciArrayKlass* array_klass, Node* *lengths, int ndimensions, int nargs) {
420 Node* length = lengths[0];
421 assert(length != NULL, "");
422 Node* array = new_array(makecon(TypeKlassPtr::make(array_klass)), length, nargs);
423 if (ndimensions > 1) {
424 jint length_con = find_int_con(length, -1);
425 guarantee(length_con >= 0, "non-constant multianewarray");
426 ciArrayKlass* array_klass_1 = array_klass->as_obj_array_klass()->element_klass()->as_array_klass();
427 const TypePtr* adr_type = TypeAryPtr::OOPS;
428 const TypeOopPtr* elemtype = _gvn.type(array)->is_aryptr()->elem()->make_oopptr();
429 const intptr_t header = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
430 for (jint i = 0; i < length_con; i++) {
431 Node* elem = expand_multianewarray(array_klass_1, &lengths[1], ndimensions-1, nargs);
432 intptr_t offset = header + ((intptr_t)i << LogBytesPerHeapOop);
433 Node* eaddr = basic_plus_adr(array, offset);
434 store_oop_to_array(control(), array, eaddr, adr_type, elem, elemtype, T_OBJECT, MemNode::unordered);
435 }
436 }
437 return array;
438 }
439
440 void Parse::do_multianewarray() {
441 int ndimensions = iter().get_dimensions();
442
443 // the m-dimensional array
444 bool will_link;
445 ciArrayKlass* array_klass = iter().get_klass(will_link)->as_array_klass();
446 assert(will_link, "multianewarray: typeflow responsibility");
447
448 // Note: Array classes are always initialized; no is_initialized check.
449
450 kill_dead_locals();
451
452 // get the lengths from the stack (first dimension is on top)
453 Node** length = NEW_RESOURCE_ARRAY(Node*, ndimensions + 1);
454 length[ndimensions] = NULL; // terminating null for make_runtime_call
455 int j;
456 for (j = ndimensions-1; j >= 0 ; j--) length[j] = pop();
457
458 // The original expression was of this form: new T[length0][length1]...
459 // It is often the case that the lengths are small (except the last).
460 // If that happens, use the fast 1-d creator a constant number of times.
461 const jint expand_limit = MIN2((jint)MultiArrayExpandLimit, 100);
462 jint expand_count = 1; // count of allocations in the expansion
463 jint expand_fanout = 1; // running total fanout
464 for (j = 0; j < ndimensions-1; j++) {
465 jint dim_con = find_int_con(length[j], -1);
466 expand_fanout *= dim_con;
467 expand_count += expand_fanout; // count the level-J sub-arrays
468 if (dim_con <= 0
469 || dim_con > expand_limit
470 || expand_count > expand_limit) {
471 expand_count = 0;
472 break;
473 }
474 }
475
476 // Can use multianewarray instead of [a]newarray if only one dimension,
477 // or if all non-final dimensions are small constants.
478 if (ndimensions == 1 || (1 <= expand_count && expand_count <= expand_limit)) {
479 Node* obj = NULL;
480 // Set the original stack and the reexecute bit for the interpreter
481 // to reexecute the multianewarray bytecode if deoptimization happens.
482 // Do it unconditionally even for one dimension multianewarray.
483 // Note: the reexecute bit will be set in GraphKit::add_safepoint_edges()
484 // when AllocateArray node for newarray is created.
485 { PreserveReexecuteState preexecs(this);
486 inc_sp(ndimensions);
487 // Pass 0 as nargs since uncommon trap code does not need to restore stack.
488 obj = expand_multianewarray(array_klass, &length[0], ndimensions, 0);
489 } //original reexecute and sp are set back here
490 push(obj);
491 return;
492 }
493
494 address fun = NULL;
495 switch (ndimensions) {
496 case 1: ShouldNotReachHere(); break;
497 case 2: fun = OptoRuntime::multianewarray2_Java(); break;
498 case 3: fun = OptoRuntime::multianewarray3_Java(); break;
499 case 4: fun = OptoRuntime::multianewarray4_Java(); break;
500 case 5: fun = OptoRuntime::multianewarray5_Java(); break;
501 };
502 Node* c = NULL;
503
504 if (fun != NULL) {
505 c = make_runtime_call(RC_NO_LEAF | RC_NO_IO,
506 OptoRuntime::multianewarray_Type(ndimensions),
507 fun, NULL, TypeRawPtr::BOTTOM,
508 makecon(TypeKlassPtr::make(array_klass)),
509 length[0], length[1], length[2],
510 (ndimensions > 2) ? length[3] : NULL,
511 (ndimensions > 3) ? length[4] : NULL);
512 } else {
513 // Create a java array for dimension sizes
514 Node* dims = NULL;
515 { PreserveReexecuteState preexecs(this);
516 inc_sp(ndimensions);
517 Node* dims_array_klass = makecon(TypeKlassPtr::make(ciArrayKlass::make(ciType::make(T_INT))));
518 dims = new_array(dims_array_klass, intcon(ndimensions), 0);
519
520 // Fill-in it with values
521 for (j = 0; j < ndimensions; j++) {
522 Node *dims_elem = array_element_address(dims, intcon(j), T_INT);
523 store_to_memory(control(), dims_elem, length[j], T_INT, TypeAryPtr::INTS, MemNode::unordered);
524 }
525 }
526
527 c = make_runtime_call(RC_NO_LEAF | RC_NO_IO,
528 OptoRuntime::multianewarrayN_Type(),
529 OptoRuntime::multianewarrayN_Java(), NULL, TypeRawPtr::BOTTOM,
530 makecon(TypeKlassPtr::make(array_klass)),
531 dims);
532 }
533 make_slow_call_ex(c, env()->Throwable_klass(), false);
534
535 Node* res = _gvn.transform(new ProjNode(c, TypeFunc::Parms));
536
537 const Type* type = TypeOopPtr::make_from_klass_raw(array_klass);
538
539 // Improve the type: We know it's not null, exact, and of a given length.
540 type = type->is_ptr()->cast_to_ptr_type(TypePtr::NotNull);
541 type = type->is_aryptr()->cast_to_exactness(true);
542
543 const TypeInt* ltype = _gvn.find_int_type(length[0]);
544 if (ltype != NULL)
545 type = type->is_aryptr()->cast_to_size(ltype);
546
547 // We cannot sharpen the nested sub-arrays, since the top level is mutable.
548
549 Node* cast = _gvn.transform( new CheckCastPPNode(control(), res, type) );
550 push(cast);
551
552 // Possible improvements:
553 // - Make a fast path for small multi-arrays. (W/ implicit init. loops.)
554 // - Issue CastII against length[*] values, to TypeInt::POS.
555 }
556
557 void Parse::do_vbox() {
558 // Obtain target type (from bytecodes)
559 bool will_link;
560 ciKlass* target_klass = iter().get_klass(will_link);
561 guarantee(will_link, "vbox: Value-capable class must be loaded");
562 guarantee(target_klass->is_instance_klass(), "vbox: Target class must be an instance type");
563
564 // Obtain source type
565 ValueTypeNode* vt = peek()->as_ValueType();
566 const TypeValueType* src_type = gvn().type(vt)->isa_valuetype();
567 guarantee(src_type != NULL, "vbox: Source type must not be null");
568 ciValueKlass* src_vk = src_type->value_klass();
569 guarantee(src_vk != NULL && src_vk->is_loaded() && src_vk->exact_klass(),
570 "vbox: Source class must be a value type and must be loaded and exact");
571
572 kill_dead_locals();
573
574 ciInstanceKlass* target_vcc_klass = target_klass->as_instance_klass();
575 ciInstanceKlass* src_vcc_klass = src_vk->vcc_klass();;
576
577 // TODO: Extend type check below if (and once) value type class hierarchies become available.
578 // (incl. extension to support dynamic type checks).
579 if (!src_vcc_klass->equals(target_vcc_klass)) {
580 builtin_throw(Deoptimization::Reason_class_check);
581 guarantee(stopped(), "A ClassCastException must be always thrown on this path");
582 return;
583 }
584 guarantee(src_vk->is_valuetype(), "vbox: Target DVT must be a value type");
585 pop();
586
587 // Create new object
588 Node* kls = makecon(TypeKlassPtr::make(target_vcc_klass));
589 Node* obj = new_instance(kls);
590
591 // Store all field values to the newly created object.
592 // The code below relies on the assumption that the VCC has the
593 // same memory layout as the derived value type.
594 // TODO: Once the layout of the two is not the same, update code below.
595 vt->as_ValueType()->store_values(this, obj, obj, target_vcc_klass);
596
597 // Push the new object onto the stack
598 push(obj);
599 }
600
601 void Parse::do_vunbox() {
602 kill_dead_locals();
603
604 // Check if the VCC instance is null.
605 Node* not_null_obj = null_check(peek());
606
607 // Value determined to be null at compile time
608 if (stopped()) {
609 return;
610 }
611
612 // Obtain target type (from bytecodes)
613 bool will_link;
614 ciKlass* target_klass = iter().get_klass(will_link);
615 guarantee(will_link, "vunbox: Derived value type must be loaded");
616 guarantee(target_klass->is_instance_klass(), "vunbox: Target class must be an instance type");
617
618 // Obtain source type
619 const TypeOopPtr* source_type = gvn().type(not_null_obj)->isa_oopptr();
620 guarantee(source_type != NULL && source_type->klass() != NULL &&
621 source_type->klass()->is_instance_klass() && source_type->klass()->is_loaded(),
622 "vunbox: Source class must be an instance type and must be loaded");
623
624 ciInstanceKlass* target_dvt_klass = target_klass->as_instance_klass();
625 ciInstanceKlass* target_vcc_klass = target_dvt_klass->vcc_klass();
626
627 // Check if the class of the source is a subclass of the value-capable class
628 // corresponding to the target.
629 // TOOD: Implement profiling of vunbox bytecodes to enable type speculation.
630 if (target_vcc_klass == NULL || !source_type->klass()->is_subclass_of(target_vcc_klass)) {
631 // It is obvious at compile-time that source and target are unrelated.
632 builtin_throw(Deoptimization::Reason_class_check);
633 guarantee(stopped(), "A ClassCastException must be always thrown on this path");
634 return;
635 }
636 guarantee(target_dvt_klass->is_valuetype(), "vunbox: Target DVT must be a value type");
637
638 if (!target_vcc_klass->equals(source_type->klass()) || !source_type->klass_is_exact()) {
639 Node* exact_obj = not_null_obj;
640 Node* slow_ctl = type_check_receiver(exact_obj, target_vcc_klass, 1.0, &exact_obj);
641 {
642 PreserveJVMState pjvms(this);
643 set_control(slow_ctl);
644 builtin_throw(Deoptimization::Reason_class_check);
645 }
646 replace_in_map(not_null_obj, exact_obj);
647 not_null_obj = exact_obj;
648 }
649
650 // Remove object from the top of the stack
651 pop();
652
653 // Create a value type node with the corresponding type
654 ciValueKlass* vk = target_dvt_klass->as_value_klass();
655 Node* vt = ValueTypeNode::make(gvn(), vk, map()->memory(), not_null_obj, not_null_obj, target_vcc_klass, vk->first_field_offset());
656
657 // Push the value type onto the stack
658 push(vt);
659 }