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
181 // Compute address and memory type.
182 int offset = field->offset_in_bytes();
183 const TypePtr* adr_type = C->alias_type(field)->adr_type();
184 Node *adr = basic_plus_adr(obj, obj, offset);
185
186 // Build the resultant type of the load
187 const Type *type;
188
189 bool must_assert_null = false;
190 if (bt == T_OBJECT || bt == T_VALUETYPE) {
191 if (!field->type()->is_loaded()) {
192 type = TypeInstPtr::BOTTOM;
193 must_assert_null = true;
194 } else if (field->is_static_constant()) {
195 // This can happen if the constant oop is non-perm.
196 ciObject* con = field->constant_value().as_object();
197 // Do not "join" in the previous type; it doesn't add value,
198 // and may yield a vacuous result if the field is of interface type.
199 if (con->is_null_object()) {
200 type = TypePtr::NULL_PTR;
201 } else {
202 type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
203 }
204 assert(type != NULL, "field singleton type must be consistent");
205 } else {
206 type = TypeOopPtr::make_from_klass(field_klass->as_klass());
207 }
208 } else {
209 type = Type::get_const_basic_type(bt);
210 }
211 if (support_IRIW_for_not_multiple_copy_atomic_cpu && field->is_volatile()) {
212 insert_mem_bar(Op_MemBarVolatile); // StoreLoad barrier
213 }
214
215 // Build the load.
216 //
217 MemNode::MemOrd mo = is_vol ? MemNode::acquire : MemNode::unordered;
218 bool needs_atomic_access = is_vol || AlwaysAtomicAccesses;
219 Node* ld = NULL;
220 if (bt == T_VALUETYPE && !field->is_static()) {
221 // Load flattened value type from non-static field
222 ld = ValueTypeNode::make(_gvn, field_klass->as_value_klass(), map()->memory(), obj, obj, field->holder(), offset);
223 } else {
224 ld = make_load(NULL, adr, type, bt, adr_type, mo, LoadNode::DependsOnlyOnTest, needs_atomic_access);
225 }
226
227 // Adjust Java stack
228 if (type2size[bt] == 1)
229 push(ld);
230 else
231 push_pair(ld);
232
233 if (must_assert_null) {
234 // Do not take a trap here. It's possible that the program
235 // will never load the field's class, and will happily see
236 // null values in this field forever. Don't stumble into a
237 // trap for such a program, or we might get a long series
238 // of useless recompilations. (Or, we might load a class
239 // which should not be loaded.) If we ever see a non-null
240 // value, we will then trap and recompile. (The trap will
241 // not need to mention the class index, since the class will
242 // already have been loaded if we ever see a non-null value.)
243 // uncommon_trap(iter().get_field_signature_index());
244 if (PrintOpto && (Verbose || WizardMode)) {
245 method()->print_name(); tty->print_cr(" asserting nullness of field at bci: %d", bci());
246 }
247 if (C->log() != NULL) {
248 C->log()->elem("assert_null reason='field' klass='%d'",
249 C->log()->identify(field->type()));
250 }
251 // If there is going to be a trap, put it at the next bytecode:
252 set_bci(iter().next_bci());
253 null_assert(peek());
254 set_bci(iter().cur_bci()); // put it back
255 }
256
257 // If reference is volatile, prevent following memory ops from
258 // floating up past the volatile read. Also prevents commoning
259 // another volatile read.
260 if (field->is_volatile()) {
261 // Memory barrier includes bogus read of value to force load BEFORE membar
262 insert_mem_bar(Op_MemBarAcquire, ld);
263 }
264 }
265
266 void Parse::do_put_xxx(Node* obj, ciField* field, bool is_field) {
267 bool is_vol = field->is_volatile();
268 // If reference is volatile, prevent following memory ops from
269 // floating down past the volatile write. Also prevents commoning
270 // another volatile read.
271 if (is_vol) insert_mem_bar(Op_MemBarRelease);
272
273 // Compute address and memory type.
274 int offset = field->offset_in_bytes();
275 const TypePtr* adr_type = C->alias_type(field)->adr_type();
276 Node* adr = basic_plus_adr(obj, obj, offset);
277 BasicType bt = field->layout_type();
278 // Value to be stored
279 Node* val = type2size[bt] == 1 ? pop() : pop_pair();
280 // Round doubles before storing
281 if (bt == T_DOUBLE) val = dstore_rounding(val);
282
283 // Conservatively release stores of object references.
284 const MemNode::MemOrd mo =
285 is_vol ?
286 // Volatile fields need releasing stores.
287 MemNode::release :
288 // Non-volatile fields also need releasing stores if they hold an
289 // object reference, because the object reference might point to
290 // a freshly created object.
291 StoreNode::release_if_reference(bt);
292
293 // Store the value.
294 if (bt == T_OBJECT || bt == T_VALUETYPE) {
295 const TypeOopPtr* field_type;
296 if (!field->type()->is_loaded()) {
297 field_type = TypeInstPtr::BOTTOM;
298 } else {
299 field_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
300 }
301 if (bt == T_VALUETYPE && !field->is_static()) {
302 // Store flattened value type to non-static field
303 val->as_ValueType()->store(this, obj, obj, field->holder(), offset);
304 } else {
305 store_oop_to_object(control(), obj, adr, adr_type, val, field_type, bt, mo);
306 }
307 } else {
308 bool needs_atomic_access = is_vol || AlwaysAtomicAccesses;
309 store_to_memory(control(), adr, val, bt, adr_type, mo, needs_atomic_access);
310 }
311
312 // If reference is volatile, prevent following volatiles ops from
313 // floating up before the volatile write.
314 if (is_vol) {
315 // If not multiple copy atomic, we do the MemBarVolatile before the load.
316 if (!support_IRIW_for_not_multiple_copy_atomic_cpu) {
317 insert_mem_bar(Op_MemBarVolatile); // Use fat membar
318 }
319 // Remember we wrote a volatile field.
320 // For not multiple copy atomic cpu (ppc64) a barrier should be issued
321 // in constructors which have such stores. See do_exits() in parse1.cpp.
322 if (is_field) {
323 set_wrote_volatile(true);
324 }
325 }
326
327 if (is_field) {
328 set_wrote_fields(true);
329 }
330
331 // If the field is final, the rules of Java say we are in <init> or <clinit>.
332 // Note the presence of writes to final non-static fields, so that we
333 // can insert a memory barrier later on to keep the writes from floating
334 // out of the constructor.
335 // Any method can write a @Stable field; insert memory barriers after those also.
336 if (is_field && (field->is_final() || field->is_stable())) {
337 if (field->is_final()) {
338 set_wrote_final(true);
339 }
340 if (field->is_stable()) {
341 set_wrote_stable(true);
342 }
343
344 // Preserve allocation ptr to create precedent edge to it in membar
345 // generated on exit from constructor.
346 // Can't bind stable with its allocation, only record allocation for final field.
347 if (field->is_final() && AllocateNode::Ideal_allocation(obj, &_gvn) != NULL) {
348 set_alloc_with_final(obj);
349 }
350 }
351 }
352
353 //=============================================================================
354
355 void Parse::do_newarray() {
356 bool will_link;
357 ciKlass* klass = iter().get_klass(will_link);
358
359 // Uncommon Trap when class that array contains is not loaded
360 // we need the loaded class for the rest of graph; do not
361 // initialize the container class (see Java spec)!!!
362 assert(will_link, "newarray: typeflow responsibility");
363
364 ciArrayKlass* array_klass = ciArrayKlass::make(klass);
365 // Check that array_klass object is loaded
366 if (!array_klass->is_loaded()) {
367 // Generate uncommon_trap for unloaded array_class
368 uncommon_trap(Deoptimization::Reason_unloaded,
369 Deoptimization::Action_reinterpret,
370 array_klass);
371 return;
372 } else if (array_klass->element_klass() != NULL &&
373 array_klass->element_klass()->is_valuetype() &&
374 !array_klass->element_klass()->as_value_klass()->is_initialized()) {
375 uncommon_trap(Deoptimization::Reason_uninitialized,
376 Deoptimization::Action_reinterpret,
377 NULL);
378 return;
379 }
380
381 kill_dead_locals();
382
383 const TypeKlassPtr* array_klass_type = TypeKlassPtr::make(array_klass);
384 Node* count_val = pop();
385 Node* obj = new_array(makecon(array_klass_type), count_val, 1);
386 push(obj);
387 }
388
389
390 void Parse::do_newarray(BasicType elem_type) {
391 kill_dead_locals();
392
393 Node* count_val = pop();
394 const TypeKlassPtr* array_klass = TypeKlassPtr::make(ciTypeArrayKlass::make(elem_type));
395 Node* obj = new_array(makecon(array_klass), count_val, 1);
396 // Push resultant oop onto stack
397 push(obj);
398 }
399
400 // Expand simple expressions like new int[3][5] and new Object[2][nonConLen].
401 // Also handle the degenerate 1-dimensional case of anewarray.
402 Node* Parse::expand_multianewarray(ciArrayKlass* array_klass, Node* *lengths, int ndimensions, int nargs) {
403 Node* length = lengths[0];
404 assert(length != NULL, "");
405 Node* array = new_array(makecon(TypeKlassPtr::make(array_klass)), length, nargs);
406 if (ndimensions > 1) {
407 jint length_con = find_int_con(length, -1);
408 guarantee(length_con >= 0, "non-constant multianewarray");
409 ciArrayKlass* array_klass_1 = array_klass->as_obj_array_klass()->element_klass()->as_array_klass();
410 const TypePtr* adr_type = TypeAryPtr::OOPS;
411 const TypeOopPtr* elemtype = _gvn.type(array)->is_aryptr()->elem()->make_oopptr();
412 const intptr_t header = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
413 for (jint i = 0; i < length_con; i++) {
414 Node* elem = expand_multianewarray(array_klass_1, &lengths[1], ndimensions-1, nargs);
415 intptr_t offset = header + ((intptr_t)i << LogBytesPerHeapOop);
416 Node* eaddr = basic_plus_adr(array, offset);
417 store_oop_to_array(control(), array, eaddr, adr_type, elem, elemtype, T_OBJECT, MemNode::unordered);
418 }
419 }
420 return array;
421 }
422
423 void Parse::do_multianewarray() {
424 int ndimensions = iter().get_dimensions();
425
426 // the m-dimensional array
427 bool will_link;
428 ciArrayKlass* array_klass = iter().get_klass(will_link)->as_array_klass();
429 assert(will_link, "multianewarray: typeflow responsibility");
430
431 // Note: Array classes are always initialized; no is_initialized check.
432
433 kill_dead_locals();
434
435 // get the lengths from the stack (first dimension is on top)
436 Node** length = NEW_RESOURCE_ARRAY(Node*, ndimensions + 1);
437 length[ndimensions] = NULL; // terminating null for make_runtime_call
438 int j;
439 for (j = ndimensions-1; j >= 0 ; j--) length[j] = pop();
440
441 // The original expression was of this form: new T[length0][length1]...
442 // It is often the case that the lengths are small (except the last).
443 // If that happens, use the fast 1-d creator a constant number of times.
444 const jint expand_limit = MIN2((jint)MultiArrayExpandLimit, 100);
445 jint expand_count = 1; // count of allocations in the expansion
446 jint expand_fanout = 1; // running total fanout
447 for (j = 0; j < ndimensions-1; j++) {
448 jint dim_con = find_int_con(length[j], -1);
449 expand_fanout *= dim_con;
450 expand_count += expand_fanout; // count the level-J sub-arrays
451 if (dim_con <= 0
452 || dim_con > expand_limit
453 || expand_count > expand_limit) {
454 expand_count = 0;
455 break;
456 }
457 }
458
459 // Can use multianewarray instead of [a]newarray if only one dimension,
460 // or if all non-final dimensions are small constants.
461 if (ndimensions == 1 || (1 <= expand_count && expand_count <= expand_limit)) {
462 Node* obj = NULL;
463 // Set the original stack and the reexecute bit for the interpreter
464 // to reexecute the multianewarray bytecode if deoptimization happens.
465 // Do it unconditionally even for one dimension multianewarray.
466 // Note: the reexecute bit will be set in GraphKit::add_safepoint_edges()
467 // when AllocateArray node for newarray is created.
468 { PreserveReexecuteState preexecs(this);
469 inc_sp(ndimensions);
470 // Pass 0 as nargs since uncommon trap code does not need to restore stack.
471 obj = expand_multianewarray(array_klass, &length[0], ndimensions, 0);
472 } //original reexecute and sp are set back here
473 push(obj);
474 return;
475 }
476
477 address fun = NULL;
478 switch (ndimensions) {
479 case 1: ShouldNotReachHere(); break;
480 case 2: fun = OptoRuntime::multianewarray2_Java(); break;
481 case 3: fun = OptoRuntime::multianewarray3_Java(); break;
482 case 4: fun = OptoRuntime::multianewarray4_Java(); break;
483 case 5: fun = OptoRuntime::multianewarray5_Java(); break;
484 };
485 Node* c = NULL;
486
487 if (fun != NULL) {
488 c = make_runtime_call(RC_NO_LEAF | RC_NO_IO,
489 OptoRuntime::multianewarray_Type(ndimensions),
490 fun, NULL, TypeRawPtr::BOTTOM,
491 makecon(TypeKlassPtr::make(array_klass)),
492 length[0], length[1], length[2],
493 (ndimensions > 2) ? length[3] : NULL,
494 (ndimensions > 3) ? length[4] : NULL);
495 } else {
496 // Create a java array for dimension sizes
497 Node* dims = NULL;
498 { PreserveReexecuteState preexecs(this);
499 inc_sp(ndimensions);
500 Node* dims_array_klass = makecon(TypeKlassPtr::make(ciArrayKlass::make(ciType::make(T_INT))));
501 dims = new_array(dims_array_klass, intcon(ndimensions), 0);
502
503 // Fill-in it with values
504 for (j = 0; j < ndimensions; j++) {
505 Node *dims_elem = array_element_address(dims, intcon(j), T_INT);
506 store_to_memory(control(), dims_elem, length[j], T_INT, TypeAryPtr::INTS, MemNode::unordered);
507 }
508 }
509
510 c = make_runtime_call(RC_NO_LEAF | RC_NO_IO,
511 OptoRuntime::multianewarrayN_Type(),
512 OptoRuntime::multianewarrayN_Java(), NULL, TypeRawPtr::BOTTOM,
513 makecon(TypeKlassPtr::make(array_klass)),
514 dims);
515 }
516 make_slow_call_ex(c, env()->Throwable_klass(), false);
517
518 Node* res = _gvn.transform(new ProjNode(c, TypeFunc::Parms));
519
520 const Type* type = TypeOopPtr::make_from_klass_raw(array_klass);
521
522 // Improve the type: We know it's not null, exact, and of a given length.
523 type = type->is_ptr()->cast_to_ptr_type(TypePtr::NotNull);
524 type = type->is_aryptr()->cast_to_exactness(true);
525
526 const TypeInt* ltype = _gvn.find_int_type(length[0]);
527 if (ltype != NULL)
528 type = type->is_aryptr()->cast_to_size(ltype);
529
530 // We cannot sharpen the nested sub-arrays, since the top level is mutable.
531
532 Node* cast = _gvn.transform( new CheckCastPPNode(control(), res, type) );
533 push(cast);
534
535 // Possible improvements:
536 // - Make a fast path for small multi-arrays. (W/ implicit init. loops.)
537 // - Issue CastII against length[*] values, to TypeInt::POS.
538 }
539
540 void Parse::do_vbox() {
541 // Obtain target type (from bytecodes)
542 bool will_link;
543 ciKlass* target_klass = iter().get_klass(will_link);
544 guarantee(will_link, "vbox: Value-capable class must be loaded");
545 guarantee(target_klass->is_instance_klass(), "vbox: Target class must be an instance type");
546
547 // Obtain source type
548 ValueTypeNode* vt = peek()->as_ValueType();
549 const TypeValueType* src_type = gvn().type(vt)->isa_valuetype();
550 guarantee(src_type != NULL, "vbox: Source type must not be null");
551 ciValueKlass* src_vk = src_type->value_klass();
552 guarantee(src_vk != NULL && src_vk->is_loaded() && src_vk->exact_klass(),
553 "vbox: Source class must be a value type and must be loaded and exact");
554
555 kill_dead_locals();
556
557 ciInstanceKlass* target_vcc_klass = target_klass->as_instance_klass();
558 ciInstanceKlass* src_vcc_klass = src_vk->vcc_klass();;
559
560 // TODO: Extend type check below if (and once) value type class hierarchies become available.
561 // (incl. extension to support dynamic type checks).
562 if (!src_vcc_klass->equals(target_vcc_klass)) {
563 builtin_throw(Deoptimization::Reason_class_check);
564 guarantee(stopped(), "A ClassCastException must be always thrown on this path");
565 return;
566 }
567 guarantee(src_vk->is_valuetype(), "vbox: Target DVT must be a value type");
568 pop();
569
570 // Create new object
571 Node* kls = makecon(TypeKlassPtr::make(target_vcc_klass));
572 Node* obj = new_instance(kls);
573
574 // Store all field values to the newly created object.
575 // The code below relies on the assumption that the VCC has the
576 // same memory layout as the derived value type.
577 // TODO: Once the layout of the two is not the same, update code below.
578 vt->as_ValueType()->store_values(this, obj, obj, target_vcc_klass);
579
580 // Push the new object onto the stack
581 push(obj);
582 }
583
584 void Parse::do_vunbox() {
585 kill_dead_locals();
586
587 // Check if the VCC instance is null.
588 Node* not_null_obj = null_check(peek());
589
590 // Value determined to be null at compile time
591 if (stopped()) {
592 return;
593 }
594
595 // Obtain target type (from bytecodes)
596 bool will_link;
597 ciKlass* target_klass = iter().get_klass(will_link);
598 guarantee(will_link, "vunbox: Derived value type must be loaded");
599 guarantee(target_klass->is_instance_klass(), "vunbox: Target class must be an instance type");
600
601 // Obtain source type
602 const TypeOopPtr* source_type = gvn().type(not_null_obj)->isa_oopptr();
603 guarantee(source_type != NULL && source_type->klass() != NULL &&
604 source_type->klass()->is_instance_klass() && source_type->klass()->is_loaded(),
605 "vunbox: Source class must be an instance type and must be loaded");
606
607 ciInstanceKlass* target_dvt_klass = target_klass->as_instance_klass();
608 ciInstanceKlass* target_vcc_klass = target_dvt_klass->vcc_klass();
609
610 // Check if the class of the source is a subclass of the value-capable class
611 // corresponding to the target.
612 // TOOD: Implement profiling of vunbox bytecodes to enable type speculation.
613 if (target_vcc_klass == NULL || !source_type->klass()->is_subclass_of(target_vcc_klass)) {
614 // It is obvious at compile-time that source and target are unrelated.
615 builtin_throw(Deoptimization::Reason_class_check);
616 guarantee(stopped(), "A ClassCastException must be always thrown on this path");
617 return;
618 }
619 guarantee(target_dvt_klass->is_valuetype(), "vunbox: Target DVT must be a value type");
620
621 if (!target_vcc_klass->equals(source_type->klass()) || !source_type->klass_is_exact()) {
622 Node* exact_obj = not_null_obj;
623 Node* slow_ctl = type_check_receiver(exact_obj, target_vcc_klass, 1.0, &exact_obj);
624 {
625 PreserveJVMState pjvms(this);
626 set_control(slow_ctl);
627 builtin_throw(Deoptimization::Reason_class_check);
628 }
629 replace_in_map(not_null_obj, exact_obj);
630 not_null_obj = exact_obj;
631 }
632
633 // Remove object from the top of the stack
634 pop();
635
636 // Create a value type node with the corresponding type
637 ciValueKlass* vk = target_dvt_klass->as_value_klass();
638 Node* vt = ValueTypeNode::make(gvn(), vk, map()->memory(), not_null_obj, not_null_obj, target_vcc_klass, vk->first_field_offset());
639
640 // Push the value type onto the stack
641 push(vt);
642 }