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