1 /*
2 * Copyright (c) 2000, 2010, 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 class BytecodeStream;
26
27 // The MethodData object collects counts and other profile information
28 // during zeroth-tier (interpretive) and first-tier execution.
29 // The profile is used later by compilation heuristics. Some heuristics
30 // enable use of aggressive (or "heroic") optimizations. An aggressive
31 // optimization often has a down-side, a corner case that it handles
32 // poorly, but which is thought to be rare. The profile provides
33 // evidence of this rarity for a given method or even BCI. It allows
34 // the compiler to back out of the optimization at places where it
35 // has historically been a poor choice. Other heuristics try to use
36 // specific information gathered about types observed at a given site.
37 //
38 // All data in the profile is approximate. It is expected to be accurate
39 // on the whole, but the system expects occasional inaccuraces, due to
40 // counter overflow, multiprocessor races during data collection, space
41 // limitations, missing MDO blocks, etc. Bad or missing data will degrade
42 // optimization quality but will not affect correctness. Also, each MDO
43 // is marked with its birth-date ("creation_mileage") which can be used
44 // to assess the quality ("maturity") of its data.
45 //
46 // Short (<32-bit) counters are designed to overflow to a known "saturated"
47 // state. Also, certain recorded per-BCI events are given one-bit counters
48 // which overflow to a saturated state which applied to all counters at
49 // that BCI. In other words, there is a small lattice which approximates
50 // the ideal of an infinite-precision counter for each event at each BCI,
51 // and the lattice quickly "bottoms out" in a state where all counters
52 // are taken to be indefinitely large.
53 //
54 // The reader will find many data races in profile gathering code, starting
55 // with invocation counter incrementation. None of these races harm correct
56 // execution of the compiled code.
57
58 // forward decl
59 class ProfileData;
60
61 // DataLayout
62 //
63 // Overlay for generic profiling data.
64 class DataLayout VALUE_OBJ_CLASS_SPEC {
65 private:
66 // Every data layout begins with a header. This header
67 // contains a tag, which is used to indicate the size/layout
68 // of the data, 4 bits of flags, which can be used in any way,
69 // 4 bits of trap history (none/one reason/many reasons),
70 // and a bci, which is used to tie this piece of data to a
71 // specific bci in the bytecodes.
72 union {
73 intptr_t _bits;
74 struct {
75 u1 _tag;
76 u1 _flags;
77 u2 _bci;
78 } _struct;
79 } _header;
80
81 // The data layout has an arbitrary number of cells, each sized
82 // to accomodate a pointer or an integer.
83 intptr_t _cells[1];
84
85 // Some types of data layouts need a length field.
86 static bool needs_array_len(u1 tag);
87
88 public:
89 enum {
90 counter_increment = 1
91 };
92
93 enum {
94 cell_size = sizeof(intptr_t)
95 };
96
97 // Tag values
98 enum {
99 no_tag,
100 bit_data_tag,
101 counter_data_tag,
102 jump_data_tag,
103 receiver_type_data_tag,
104 virtual_call_data_tag,
105 ret_data_tag,
106 branch_data_tag,
107 multi_branch_data_tag,
108 arg_info_data_tag
109 };
110
111 enum {
112 // The _struct._flags word is formatted as [trap_state:4 | flags:4].
113 // The trap state breaks down further as [recompile:1 | reason:3].
114 // This further breakdown is defined in deoptimization.cpp.
115 // See Deoptimization::trap_state_reason for an assert that
116 // trap_bits is big enough to hold reasons < Reason_RECORDED_LIMIT.
117 //
118 // The trap_state is collected only if ProfileTraps is true.
119 trap_bits = 1+3, // 3: enough to distinguish [0..Reason_RECORDED_LIMIT].
120 trap_shift = BitsPerByte - trap_bits,
121 trap_mask = right_n_bits(trap_bits),
122 trap_mask_in_place = (trap_mask << trap_shift),
123 flag_limit = trap_shift,
124 flag_mask = right_n_bits(flag_limit),
125 first_flag = 0
126 };
127
128 // Size computation
129 static int header_size_in_bytes() {
130 return cell_size;
131 }
132 static int header_size_in_cells() {
133 return 1;
134 }
135
136 static int compute_size_in_bytes(int cell_count) {
137 return header_size_in_bytes() + cell_count * cell_size;
138 }
139
140 // Initialization
141 void initialize(u1 tag, u2 bci, int cell_count);
142
143 // Accessors
144 u1 tag() {
145 return _header._struct._tag;
146 }
147
148 // Return a few bits of trap state. Range is [0..trap_mask].
149 // The state tells if traps with zero, one, or many reasons have occurred.
150 // It also tells whether zero or many recompilations have occurred.
151 // The associated trap histogram in the MDO itself tells whether
152 // traps are common or not. If a BCI shows that a trap X has
153 // occurred, and the MDO shows N occurrences of X, we make the
154 // simplifying assumption that all N occurrences can be blamed
155 // on that BCI.
156 int trap_state() {
157 return ((_header._struct._flags >> trap_shift) & trap_mask);
158 }
159
160 void set_trap_state(int new_state) {
161 assert(ProfileTraps, "used only under +ProfileTraps");
162 uint old_flags = (_header._struct._flags & flag_mask);
163 _header._struct._flags = (new_state << trap_shift) | old_flags;
164 }
165
166 u1 flags() {
167 return _header._struct._flags;
168 }
169
170 u2 bci() {
171 return _header._struct._bci;
172 }
173
174 void set_header(intptr_t value) {
175 _header._bits = value;
176 }
177 void release_set_header(intptr_t value) {
178 OrderAccess::release_store_ptr(&_header._bits, value);
179 }
180 intptr_t header() {
181 return _header._bits;
182 }
183 void set_cell_at(int index, intptr_t value) {
184 _cells[index] = value;
185 }
186 void release_set_cell_at(int index, intptr_t value) {
187 OrderAccess::release_store_ptr(&_cells[index], value);
188 }
189 intptr_t cell_at(int index) {
190 return _cells[index];
191 }
192 intptr_t* adr_cell_at(int index) {
193 return &_cells[index];
194 }
195 oop* adr_oop_at(int index) {
196 return (oop*)&(_cells[index]);
197 }
198
199 void set_flag_at(int flag_number) {
200 assert(flag_number < flag_limit, "oob");
201 _header._struct._flags |= (0x1 << flag_number);
202 }
203 bool flag_at(int flag_number) {
204 assert(flag_number < flag_limit, "oob");
205 return (_header._struct._flags & (0x1 << flag_number)) != 0;
206 }
207
208 // Low-level support for code generation.
209 static ByteSize header_offset() {
210 return byte_offset_of(DataLayout, _header);
211 }
212 static ByteSize tag_offset() {
213 return byte_offset_of(DataLayout, _header._struct._tag);
214 }
215 static ByteSize flags_offset() {
216 return byte_offset_of(DataLayout, _header._struct._flags);
217 }
218 static ByteSize bci_offset() {
219 return byte_offset_of(DataLayout, _header._struct._bci);
220 }
221 static ByteSize cell_offset(int index) {
222 return byte_offset_of(DataLayout, _cells[index]);
223 }
224 // Return a value which, when or-ed as a byte into _flags, sets the flag.
225 static int flag_number_to_byte_constant(int flag_number) {
226 assert(0 <= flag_number && flag_number < flag_limit, "oob");
227 DataLayout temp; temp.set_header(0);
228 temp.set_flag_at(flag_number);
229 return temp._header._struct._flags;
230 }
231 // Return a value which, when or-ed as a word into _header, sets the flag.
232 static intptr_t flag_mask_to_header_mask(int byte_constant) {
233 DataLayout temp; temp.set_header(0);
234 temp._header._struct._flags = byte_constant;
235 return temp._header._bits;
236 }
237
238 // GC support
239 ProfileData* data_in();
240 void follow_weak_refs(BoolObjectClosure* cl);
241 };
242
243
244 // ProfileData class hierarchy
245 class ProfileData;
246 class BitData;
247 class CounterData;
248 class ReceiverTypeData;
249 class VirtualCallData;
250 class RetData;
251 class JumpData;
252 class BranchData;
253 class ArrayData;
254 class MultiBranchData;
255 class ArgInfoData;
256
257
258 // ProfileData
259 //
260 // A ProfileData object is created to refer to a section of profiling
261 // data in a structured way.
262 class ProfileData : public ResourceObj {
263 private:
264 #ifndef PRODUCT
265 enum {
266 tab_width_one = 16,
267 tab_width_two = 36
268 };
269 #endif // !PRODUCT
270
271 // This is a pointer to a section of profiling data.
272 DataLayout* _data;
273
274 protected:
275 DataLayout* data() { return _data; }
276
277 enum {
278 cell_size = DataLayout::cell_size
279 };
280
281 public:
282 // How many cells are in this?
283 virtual int cell_count() {
284 ShouldNotReachHere();
285 return -1;
286 }
287
288 // Return the size of this data.
289 int size_in_bytes() {
290 return DataLayout::compute_size_in_bytes(cell_count());
291 }
292
293 protected:
294 // Low-level accessors for underlying data
295 void set_intptr_at(int index, intptr_t value) {
296 assert(0 <= index && index < cell_count(), "oob");
297 data()->set_cell_at(index, value);
298 }
299 void release_set_intptr_at(int index, intptr_t value) {
300 assert(0 <= index && index < cell_count(), "oob");
301 data()->release_set_cell_at(index, value);
302 }
303 intptr_t intptr_at(int index) {
304 assert(0 <= index && index < cell_count(), "oob");
305 return data()->cell_at(index);
306 }
307 void set_uint_at(int index, uint value) {
308 set_intptr_at(index, (intptr_t) value);
309 }
310 void release_set_uint_at(int index, uint value) {
311 release_set_intptr_at(index, (intptr_t) value);
312 }
313 uint uint_at(int index) {
314 return (uint)intptr_at(index);
315 }
316 void set_int_at(int index, int value) {
317 set_intptr_at(index, (intptr_t) value);
318 }
319 void release_set_int_at(int index, int value) {
320 release_set_intptr_at(index, (intptr_t) value);
321 }
322 int int_at(int index) {
323 return (int)intptr_at(index);
324 }
325 int int_at_unchecked(int index) {
326 return (int)data()->cell_at(index);
327 }
328 void set_oop_at(int index, oop value) {
329 set_intptr_at(index, (intptr_t) value);
330 }
331 oop oop_at(int index) {
332 return (oop)intptr_at(index);
333 }
334 oop* adr_oop_at(int index) {
335 assert(0 <= index && index < cell_count(), "oob");
336 return data()->adr_oop_at(index);
337 }
338
339 void set_flag_at(int flag_number) {
340 data()->set_flag_at(flag_number);
341 }
342 bool flag_at(int flag_number) {
343 return data()->flag_at(flag_number);
344 }
345
346 // two convenient imports for use by subclasses:
347 static ByteSize cell_offset(int index) {
348 return DataLayout::cell_offset(index);
349 }
350 static int flag_number_to_byte_constant(int flag_number) {
351 return DataLayout::flag_number_to_byte_constant(flag_number);
352 }
353
354 ProfileData(DataLayout* data) {
355 _data = data;
356 }
357
358 public:
359 // Constructor for invalid ProfileData.
360 ProfileData();
361
362 u2 bci() {
363 return data()->bci();
364 }
365
366 address dp() {
367 return (address)_data;
368 }
369
370 int trap_state() {
371 return data()->trap_state();
372 }
373 void set_trap_state(int new_state) {
374 data()->set_trap_state(new_state);
375 }
376
377 // Type checking
378 virtual bool is_BitData() { return false; }
379 virtual bool is_CounterData() { return false; }
380 virtual bool is_JumpData() { return false; }
381 virtual bool is_ReceiverTypeData(){ return false; }
382 virtual bool is_VirtualCallData() { return false; }
383 virtual bool is_RetData() { return false; }
384 virtual bool is_BranchData() { return false; }
385 virtual bool is_ArrayData() { return false; }
386 virtual bool is_MultiBranchData() { return false; }
387 virtual bool is_ArgInfoData() { return false; }
388
389
390 BitData* as_BitData() {
391 assert(is_BitData(), "wrong type");
392 return is_BitData() ? (BitData*) this : NULL;
393 }
394 CounterData* as_CounterData() {
395 assert(is_CounterData(), "wrong type");
396 return is_CounterData() ? (CounterData*) this : NULL;
397 }
398 JumpData* as_JumpData() {
399 assert(is_JumpData(), "wrong type");
400 return is_JumpData() ? (JumpData*) this : NULL;
401 }
402 ReceiverTypeData* as_ReceiverTypeData() {
403 assert(is_ReceiverTypeData(), "wrong type");
404 return is_ReceiverTypeData() ? (ReceiverTypeData*)this : NULL;
405 }
406 VirtualCallData* as_VirtualCallData() {
407 assert(is_VirtualCallData(), "wrong type");
408 return is_VirtualCallData() ? (VirtualCallData*)this : NULL;
409 }
410 RetData* as_RetData() {
411 assert(is_RetData(), "wrong type");
412 return is_RetData() ? (RetData*) this : NULL;
413 }
414 BranchData* as_BranchData() {
415 assert(is_BranchData(), "wrong type");
416 return is_BranchData() ? (BranchData*) this : NULL;
417 }
418 ArrayData* as_ArrayData() {
419 assert(is_ArrayData(), "wrong type");
420 return is_ArrayData() ? (ArrayData*) this : NULL;
421 }
422 MultiBranchData* as_MultiBranchData() {
423 assert(is_MultiBranchData(), "wrong type");
424 return is_MultiBranchData() ? (MultiBranchData*)this : NULL;
425 }
426 ArgInfoData* as_ArgInfoData() {
427 assert(is_ArgInfoData(), "wrong type");
428 return is_ArgInfoData() ? (ArgInfoData*)this : NULL;
429 }
430
431
432 // Subclass specific initialization
433 virtual void post_initialize(BytecodeStream* stream, methodDataOop mdo) {}
434
435 // GC support
436 virtual void follow_contents() {}
437 virtual void oop_iterate(OopClosure* blk) {}
438 virtual void oop_iterate_m(OopClosure* blk, MemRegion mr) {}
439 virtual void adjust_pointers() {}
440 virtual void follow_weak_refs(BoolObjectClosure* is_alive_closure) {}
441
442 #ifndef SERIALGC
443 // Parallel old support
444 virtual void follow_contents(ParCompactionManager* cm) {}
445 virtual void update_pointers() {}
446 virtual void update_pointers(HeapWord* beg_addr, HeapWord* end_addr) {}
447 #endif // SERIALGC
448
449 // CI translation: ProfileData can represent both MethodDataOop data
450 // as well as CIMethodData data. This function is provided for translating
451 // an oop in a ProfileData to the ci equivalent. Generally speaking,
452 // most ProfileData don't require any translation, so we provide the null
453 // translation here, and the required translators are in the ci subclasses.
454 virtual void translate_from(ProfileData* data) {}
455
456 virtual void print_data_on(outputStream* st) {
457 ShouldNotReachHere();
458 }
459
460 #ifndef PRODUCT
461 void print_shared(outputStream* st, const char* name);
462 void tab(outputStream* st);
463 #endif
464 };
465
466 // BitData
467 //
468 // A BitData holds a flag or two in its header.
469 class BitData : public ProfileData {
470 protected:
471 enum {
472 // null_seen:
473 // saw a null operand (cast/aastore/instanceof)
474 null_seen_flag = DataLayout::first_flag + 0
475 };
476 enum { bit_cell_count = 0 }; // no additional data fields needed.
477 public:
478 BitData(DataLayout* layout) : ProfileData(layout) {
479 }
480
481 virtual bool is_BitData() { return true; }
482
483 static int static_cell_count() {
484 return bit_cell_count;
485 }
486
487 virtual int cell_count() {
488 return static_cell_count();
489 }
490
491 // Accessor
492
493 // The null_seen flag bit is specially known to the interpreter.
494 // Consulting it allows the compiler to avoid setting up null_check traps.
495 bool null_seen() { return flag_at(null_seen_flag); }
496 void set_null_seen() { set_flag_at(null_seen_flag); }
497
498
499 // Code generation support
500 static int null_seen_byte_constant() {
501 return flag_number_to_byte_constant(null_seen_flag);
502 }
503
504 static ByteSize bit_data_size() {
505 return cell_offset(bit_cell_count);
506 }
507
508 #ifndef PRODUCT
509 void print_data_on(outputStream* st);
510 #endif
511 };
512
513 // CounterData
514 //
515 // A CounterData corresponds to a simple counter.
516 class CounterData : public BitData {
517 protected:
518 enum {
519 count_off,
520 counter_cell_count
521 };
522 public:
523 CounterData(DataLayout* layout) : BitData(layout) {}
524
525 virtual bool is_CounterData() { return true; }
526
527 static int static_cell_count() {
528 return counter_cell_count;
529 }
530
531 virtual int cell_count() {
532 return static_cell_count();
533 }
534
535 // Direct accessor
536 uint count() {
537 return uint_at(count_off);
538 }
539
540 // Code generation support
541 static ByteSize count_offset() {
542 return cell_offset(count_off);
543 }
544 static ByteSize counter_data_size() {
545 return cell_offset(counter_cell_count);
546 }
547
548 void set_count(uint count) {
549 set_uint_at(count_off, count);
550 }
551
552 #ifndef PRODUCT
553 void print_data_on(outputStream* st);
554 #endif
555 };
556
557 // JumpData
558 //
559 // A JumpData is used to access profiling information for a direct
560 // branch. It is a counter, used for counting the number of branches,
561 // plus a data displacement, used for realigning the data pointer to
562 // the corresponding target bci.
563 class JumpData : public ProfileData {
564 protected:
565 enum {
566 taken_off_set,
567 displacement_off_set,
568 jump_cell_count
569 };
570
571 void set_displacement(int displacement) {
572 set_int_at(displacement_off_set, displacement);
573 }
574
575 public:
576 JumpData(DataLayout* layout) : ProfileData(layout) {
577 assert(layout->tag() == DataLayout::jump_data_tag ||
578 layout->tag() == DataLayout::branch_data_tag, "wrong type");
579 }
580
581 virtual bool is_JumpData() { return true; }
582
583 static int static_cell_count() {
584 return jump_cell_count;
585 }
586
587 virtual int cell_count() {
588 return static_cell_count();
589 }
590
591 // Direct accessor
592 uint taken() {
593 return uint_at(taken_off_set);
594 }
595 // Saturating counter
596 uint inc_taken() {
597 uint cnt = taken() + 1;
598 // Did we wrap? Will compiler screw us??
599 if (cnt == 0) cnt--;
600 set_uint_at(taken_off_set, cnt);
601 return cnt;
602 }
603
604 int displacement() {
605 return int_at(displacement_off_set);
606 }
607
608 // Code generation support
609 static ByteSize taken_offset() {
610 return cell_offset(taken_off_set);
611 }
612
613 static ByteSize displacement_offset() {
614 return cell_offset(displacement_off_set);
615 }
616
617 // Specific initialization.
618 void post_initialize(BytecodeStream* stream, methodDataOop mdo);
619
620 #ifndef PRODUCT
621 void print_data_on(outputStream* st);
622 #endif
623 };
624
625 // ReceiverTypeData
626 //
627 // A ReceiverTypeData is used to access profiling information about a
628 // dynamic type check. It consists of a counter which counts the total times
629 // that the check is reached, and a series of (klassOop, count) pairs
630 // which are used to store a type profile for the receiver of the check.
631 class ReceiverTypeData : public CounterData {
632 protected:
633 enum {
634 receiver0_offset = counter_cell_count,
635 count0_offset,
636 receiver_type_row_cell_count = (count0_offset + 1) - receiver0_offset
637 };
638
639 public:
640 ReceiverTypeData(DataLayout* layout) : CounterData(layout) {
641 assert(layout->tag() == DataLayout::receiver_type_data_tag ||
642 layout->tag() == DataLayout::virtual_call_data_tag, "wrong type");
643 }
644
645 virtual bool is_ReceiverTypeData() { return true; }
646
647 static int static_cell_count() {
648 return counter_cell_count + (uint) TypeProfileWidth * receiver_type_row_cell_count;
649 }
650
651 virtual int cell_count() {
652 return static_cell_count();
653 }
654
655 // Direct accessors
656 static uint row_limit() {
657 return TypeProfileWidth;
658 }
659 static int receiver_cell_index(uint row) {
660 return receiver0_offset + row * receiver_type_row_cell_count;
661 }
662 static int receiver_count_cell_index(uint row) {
663 return count0_offset + row * receiver_type_row_cell_count;
664 }
665
666 // Get the receiver at row. The 'unchecked' version is needed by parallel old
667 // gc; it does not assert the receiver is a klass. During compaction of the
668 // perm gen, the klass may already have moved, so the is_klass() predicate
669 // would fail. The 'normal' version should be used whenever possible.
670 klassOop receiver_unchecked(uint row) {
671 assert(row < row_limit(), "oob");
672 oop recv = oop_at(receiver_cell_index(row));
673 return (klassOop)recv;
674 }
675
676 klassOop receiver(uint row) {
677 klassOop recv = receiver_unchecked(row);
678 assert(recv == NULL || ((oop)recv)->is_klass(), "wrong type");
679 return recv;
680 }
681
682 void set_receiver(uint row, oop p) {
683 assert((uint)row < row_limit(), "oob");
684 set_oop_at(receiver_cell_index(row), p);
685 }
686
687 uint receiver_count(uint row) {
688 assert(row < row_limit(), "oob");
689 return uint_at(receiver_count_cell_index(row));
690 }
691
692 void set_receiver_count(uint row, uint count) {
693 assert(row < row_limit(), "oob");
694 set_uint_at(receiver_count_cell_index(row), count);
695 }
696
697 void clear_row(uint row) {
698 assert(row < row_limit(), "oob");
699 // Clear total count - indicator of polymorphic call site.
700 // The site may look like as monomorphic after that but
701 // it allow to have more accurate profiling information because
702 // there was execution phase change since klasses were unloaded.
703 // If the site is still polymorphic then MDO will be updated
704 // to reflect it. But it could be the case that the site becomes
705 // only bimorphic. Then keeping total count not 0 will be wrong.
706 // Even if we use monomorphic (when it is not) for compilation
707 // we will only have trap, deoptimization and recompile again
708 // with updated MDO after executing method in Interpreter.
709 // An additional receiver will be recorded in the cleaned row
710 // during next call execution.
711 //
712 // Note: our profiling logic works with empty rows in any slot.
713 // We do sorting a profiling info (ciCallProfile) for compilation.
714 //
715 set_count(0);
716 set_receiver(row, NULL);
717 set_receiver_count(row, 0);
718 }
719
720 // Code generation support
721 static ByteSize receiver_offset(uint row) {
722 return cell_offset(receiver_cell_index(row));
723 }
724 static ByteSize receiver_count_offset(uint row) {
725 return cell_offset(receiver_count_cell_index(row));
726 }
727 static ByteSize receiver_type_data_size() {
728 return cell_offset(static_cell_count());
729 }
730
731 // GC support
732 virtual void follow_contents();
733 virtual void oop_iterate(OopClosure* blk);
734 virtual void oop_iterate_m(OopClosure* blk, MemRegion mr);
735 virtual void adjust_pointers();
736 virtual void follow_weak_refs(BoolObjectClosure* is_alive_closure);
737
738 #ifndef SERIALGC
739 // Parallel old support
740 virtual void follow_contents(ParCompactionManager* cm);
741 virtual void update_pointers();
742 virtual void update_pointers(HeapWord* beg_addr, HeapWord* end_addr);
743 #endif // SERIALGC
744
745 oop* adr_receiver(uint row) {
746 return adr_oop_at(receiver_cell_index(row));
747 }
748
749 #ifndef PRODUCT
750 void print_receiver_data_on(outputStream* st);
751 void print_data_on(outputStream* st);
752 #endif
753 };
754
755 // VirtualCallData
756 //
757 // A VirtualCallData is used to access profiling information about a
758 // virtual call. For now, it has nothing more than a ReceiverTypeData.
759 class VirtualCallData : public ReceiverTypeData {
760 public:
761 VirtualCallData(DataLayout* layout) : ReceiverTypeData(layout) {
762 assert(layout->tag() == DataLayout::virtual_call_data_tag, "wrong type");
763 }
764
765 virtual bool is_VirtualCallData() { return true; }
766
767 static int static_cell_count() {
768 // At this point we could add more profile state, e.g., for arguments.
769 // But for now it's the same size as the base record type.
770 return ReceiverTypeData::static_cell_count();
771 }
772
773 virtual int cell_count() {
774 return static_cell_count();
775 }
776
777 // Direct accessors
778 static ByteSize virtual_call_data_size() {
779 return cell_offset(static_cell_count());
780 }
781
782 #ifndef PRODUCT
783 void print_data_on(outputStream* st);
784 #endif
785 };
786
787 // RetData
788 //
789 // A RetData is used to access profiling information for a ret bytecode.
790 // It is composed of a count of the number of times that the ret has
791 // been executed, followed by a series of triples of the form
792 // (bci, count, di) which count the number of times that some bci was the
793 // target of the ret and cache a corresponding data displacement.
794 class RetData : public CounterData {
795 protected:
796 enum {
797 bci0_offset = counter_cell_count,
798 count0_offset,
799 displacement0_offset,
800 ret_row_cell_count = (displacement0_offset + 1) - bci0_offset
801 };
802
803 void set_bci(uint row, int bci) {
804 assert((uint)row < row_limit(), "oob");
805 set_int_at(bci0_offset + row * ret_row_cell_count, bci);
806 }
807 void release_set_bci(uint row, int bci) {
808 assert((uint)row < row_limit(), "oob");
809 // 'release' when setting the bci acts as a valid flag for other
810 // threads wrt bci_count and bci_displacement.
811 release_set_int_at(bci0_offset + row * ret_row_cell_count, bci);
812 }
813 void set_bci_count(uint row, uint count) {
814 assert((uint)row < row_limit(), "oob");
815 set_uint_at(count0_offset + row * ret_row_cell_count, count);
816 }
817 void set_bci_displacement(uint row, int disp) {
818 set_int_at(displacement0_offset + row * ret_row_cell_count, disp);
819 }
820
821 public:
822 RetData(DataLayout* layout) : CounterData(layout) {
823 assert(layout->tag() == DataLayout::ret_data_tag, "wrong type");
824 }
825
826 virtual bool is_RetData() { return true; }
827
828 enum {
829 no_bci = -1 // value of bci when bci1/2 are not in use.
830 };
831
832 static int static_cell_count() {
833 return counter_cell_count + (uint) BciProfileWidth * ret_row_cell_count;
834 }
835
836 virtual int cell_count() {
837 return static_cell_count();
838 }
839
840 static uint row_limit() {
841 return BciProfileWidth;
842 }
843 static int bci_cell_index(uint row) {
844 return bci0_offset + row * ret_row_cell_count;
845 }
846 static int bci_count_cell_index(uint row) {
847 return count0_offset + row * ret_row_cell_count;
848 }
849 static int bci_displacement_cell_index(uint row) {
850 return displacement0_offset + row * ret_row_cell_count;
851 }
852
853 // Direct accessors
854 int bci(uint row) {
855 return int_at(bci_cell_index(row));
856 }
857 uint bci_count(uint row) {
858 return uint_at(bci_count_cell_index(row));
859 }
860 int bci_displacement(uint row) {
861 return int_at(bci_displacement_cell_index(row));
862 }
863
864 // Interpreter Runtime support
865 address fixup_ret(int return_bci, methodDataHandle mdo);
866
867 // Code generation support
868 static ByteSize bci_offset(uint row) {
869 return cell_offset(bci_cell_index(row));
870 }
871 static ByteSize bci_count_offset(uint row) {
872 return cell_offset(bci_count_cell_index(row));
873 }
874 static ByteSize bci_displacement_offset(uint row) {
875 return cell_offset(bci_displacement_cell_index(row));
876 }
877
878 // Specific initialization.
879 void post_initialize(BytecodeStream* stream, methodDataOop mdo);
880
881 #ifndef PRODUCT
882 void print_data_on(outputStream* st);
883 #endif
884 };
885
886 // BranchData
887 //
888 // A BranchData is used to access profiling data for a two-way branch.
889 // It consists of taken and not_taken counts as well as a data displacement
890 // for the taken case.
891 class BranchData : public JumpData {
892 protected:
893 enum {
894 not_taken_off_set = jump_cell_count,
895 branch_cell_count
896 };
897
898 void set_displacement(int displacement) {
899 set_int_at(displacement_off_set, displacement);
900 }
901
902 public:
903 BranchData(DataLayout* layout) : JumpData(layout) {
904 assert(layout->tag() == DataLayout::branch_data_tag, "wrong type");
905 }
906
907 virtual bool is_BranchData() { return true; }
908
909 static int static_cell_count() {
910 return branch_cell_count;
911 }
912
913 virtual int cell_count() {
914 return static_cell_count();
915 }
916
917 // Direct accessor
918 uint not_taken() {
919 return uint_at(not_taken_off_set);
920 }
921
922 uint inc_not_taken() {
923 uint cnt = not_taken() + 1;
924 // Did we wrap? Will compiler screw us??
925 if (cnt == 0) cnt--;
926 set_uint_at(not_taken_off_set, cnt);
927 return cnt;
928 }
929
930 // Code generation support
931 static ByteSize not_taken_offset() {
932 return cell_offset(not_taken_off_set);
933 }
934 static ByteSize branch_data_size() {
935 return cell_offset(branch_cell_count);
936 }
937
938 // Specific initialization.
939 void post_initialize(BytecodeStream* stream, methodDataOop mdo);
940
941 #ifndef PRODUCT
942 void print_data_on(outputStream* st);
943 #endif
944 };
945
946 // ArrayData
947 //
948 // A ArrayData is a base class for accessing profiling data which does
949 // not have a statically known size. It consists of an array length
950 // and an array start.
951 class ArrayData : public ProfileData {
952 protected:
953 friend class DataLayout;
954
955 enum {
956 array_len_off_set,
957 array_start_off_set
958 };
959
960 uint array_uint_at(int index) {
961 int aindex = index + array_start_off_set;
962 return uint_at(aindex);
963 }
964 int array_int_at(int index) {
965 int aindex = index + array_start_off_set;
966 return int_at(aindex);
967 }
968 oop array_oop_at(int index) {
969 int aindex = index + array_start_off_set;
970 return oop_at(aindex);
971 }
972 void array_set_int_at(int index, int value) {
973 int aindex = index + array_start_off_set;
974 set_int_at(aindex, value);
975 }
976
977 // Code generation support for subclasses.
978 static ByteSize array_element_offset(int index) {
979 return cell_offset(array_start_off_set + index);
980 }
981
982 public:
983 ArrayData(DataLayout* layout) : ProfileData(layout) {}
984
985 virtual bool is_ArrayData() { return true; }
986
987 static int static_cell_count() {
988 return -1;
989 }
990
991 int array_len() {
992 return int_at_unchecked(array_len_off_set);
993 }
994
995 virtual int cell_count() {
996 return array_len() + 1;
997 }
998
999 // Code generation support
1000 static ByteSize array_len_offset() {
1001 return cell_offset(array_len_off_set);
1002 }
1003 static ByteSize array_start_offset() {
1004 return cell_offset(array_start_off_set);
1005 }
1006 };
1007
1008 // MultiBranchData
1009 //
1010 // A MultiBranchData is used to access profiling information for
1011 // a multi-way branch (*switch bytecodes). It consists of a series
1012 // of (count, displacement) pairs, which count the number of times each
1013 // case was taken and specify the data displacment for each branch target.
1014 class MultiBranchData : public ArrayData {
1015 protected:
1016 enum {
1017 default_count_off_set,
1018 default_disaplacement_off_set,
1019 case_array_start
1020 };
1021 enum {
1022 relative_count_off_set,
1023 relative_displacement_off_set,
1024 per_case_cell_count
1025 };
1026
1027 void set_default_displacement(int displacement) {
1028 array_set_int_at(default_disaplacement_off_set, displacement);
1029 }
1030 void set_displacement_at(int index, int displacement) {
1031 array_set_int_at(case_array_start +
1032 index * per_case_cell_count +
1033 relative_displacement_off_set,
1034 displacement);
1035 }
1036
1037 public:
1038 MultiBranchData(DataLayout* layout) : ArrayData(layout) {
1039 assert(layout->tag() == DataLayout::multi_branch_data_tag, "wrong type");
1040 }
1041
1042 virtual bool is_MultiBranchData() { return true; }
1043
1044 static int compute_cell_count(BytecodeStream* stream);
1045
1046 int number_of_cases() {
1047 int alen = array_len() - 2; // get rid of default case here.
1048 assert(alen % per_case_cell_count == 0, "must be even");
1049 return (alen / per_case_cell_count);
1050 }
1051
1052 uint default_count() {
1053 return array_uint_at(default_count_off_set);
1054 }
1055 int default_displacement() {
1056 return array_int_at(default_disaplacement_off_set);
1057 }
1058
1059 uint count_at(int index) {
1060 return array_uint_at(case_array_start +
1061 index * per_case_cell_count +
1062 relative_count_off_set);
1063 }
1064 int displacement_at(int index) {
1065 return array_int_at(case_array_start +
1066 index * per_case_cell_count +
1067 relative_displacement_off_set);
1068 }
1069
1070 // Code generation support
1071 static ByteSize default_count_offset() {
1072 return array_element_offset(default_count_off_set);
1073 }
1074 static ByteSize default_displacement_offset() {
1075 return array_element_offset(default_disaplacement_off_set);
1076 }
1077 static ByteSize case_count_offset(int index) {
1078 return case_array_offset() +
1079 (per_case_size() * index) +
1080 relative_count_offset();
1081 }
1082 static ByteSize case_array_offset() {
1083 return array_element_offset(case_array_start);
1084 }
1085 static ByteSize per_case_size() {
1086 return in_ByteSize(per_case_cell_count) * cell_size;
1087 }
1088 static ByteSize relative_count_offset() {
1089 return in_ByteSize(relative_count_off_set) * cell_size;
1090 }
1091 static ByteSize relative_displacement_offset() {
1092 return in_ByteSize(relative_displacement_off_set) * cell_size;
1093 }
1094
1095 // Specific initialization.
1096 void post_initialize(BytecodeStream* stream, methodDataOop mdo);
1097
1098 #ifndef PRODUCT
1099 void print_data_on(outputStream* st);
1100 #endif
1101 };
1102
1103 class ArgInfoData : public ArrayData {
1104
1105 public:
1106 ArgInfoData(DataLayout* layout) : ArrayData(layout) {
1107 assert(layout->tag() == DataLayout::arg_info_data_tag, "wrong type");
1108 }
1109
1110 virtual bool is_ArgInfoData() { return true; }
1111
1112
1113 int number_of_args() {
1114 return array_len();
1115 }
1116
1117 uint arg_modified(int arg) {
1118 return array_uint_at(arg);
1119 }
1120
1121 void set_arg_modified(int arg, uint val) {
1122 array_set_int_at(arg, val);
1123 }
1124
1125 #ifndef PRODUCT
1126 void print_data_on(outputStream* st);
1127 #endif
1128 };
1129
1130 // methodDataOop
1131 //
1132 // A methodDataOop holds information which has been collected about
1133 // a method. Its layout looks like this:
1134 //
1135 // -----------------------------
1136 // | header |
1137 // | klass |
1138 // -----------------------------
1139 // | method |
1140 // | size of the methodDataOop |
1141 // -----------------------------
1142 // | Data entries... |
1143 // | (variable size) |
1144 // | |
1145 // . .
1146 // . .
1147 // . .
1148 // | |
1149 // -----------------------------
1150 //
1151 // The data entry area is a heterogeneous array of DataLayouts. Each
1152 // DataLayout in the array corresponds to a specific bytecode in the
1153 // method. The entries in the array are sorted by the corresponding
1154 // bytecode. Access to the data is via resource-allocated ProfileData,
1155 // which point to the underlying blocks of DataLayout structures.
1156 //
1157 // During interpretation, if profiling in enabled, the interpreter
1158 // maintains a method data pointer (mdp), which points at the entry
1159 // in the array corresponding to the current bci. In the course of
1160 // intepretation, when a bytecode is encountered that has profile data
1161 // associated with it, the entry pointed to by mdp is updated, then the
1162 // mdp is adjusted to point to the next appropriate DataLayout. If mdp
1163 // is NULL to begin with, the interpreter assumes that the current method
1164 // is not (yet) being profiled.
1165 //
1166 // In methodDataOop parlance, "dp" is a "data pointer", the actual address
1167 // of a DataLayout element. A "di" is a "data index", the offset in bytes
1168 // from the base of the data entry array. A "displacement" is the byte offset
1169 // in certain ProfileData objects that indicate the amount the mdp must be
1170 // adjusted in the event of a change in control flow.
1171 //
1172
1173 class methodDataOopDesc : public oopDesc {
1174 friend class VMStructs;
1175 private:
1176 friend class ProfileData;
1177
1178 // Back pointer to the methodOop
1179 methodOop _method;
1180
1181 // Size of this oop in bytes
1182 int _size;
1183
1184 // Cached hint for bci_to_dp and bci_to_data
1185 int _hint_di;
1186
1187 // Whole-method sticky bits and flags
1188 public:
1189 enum {
1190 _trap_hist_limit = 16, // decoupled from Deoptimization::Reason_LIMIT
1191 _trap_hist_mask = max_jubyte,
1192 _extra_data_count = 4 // extra DataLayout headers, for trap history
1193 }; // Public flag values
1194 private:
1195 uint _nof_decompiles; // count of all nmethod removals
1196 uint _nof_overflow_recompiles; // recompile count, excluding recomp. bits
1197 uint _nof_overflow_traps; // trap count, excluding _trap_hist
1198 union {
1199 intptr_t _align;
1200 u1 _array[_trap_hist_limit];
1201 } _trap_hist;
1202
1203 // Support for interprocedural escape analysis, from Thomas Kotzmann.
1204 intx _eflags; // flags on escape information
1205 intx _arg_local; // bit set of non-escaping arguments
1206 intx _arg_stack; // bit set of stack-allocatable arguments
1207 intx _arg_returned; // bit set of returned arguments
1208
1209 int _creation_mileage; // method mileage at MDO creation
1210
1211 // How many invocations has this MDO seen?
1212 // These counters are used to determine the exact age of MDO.
1213 // We need those because in tiered a method can be concurrently
1214 // executed at different levels.
1215 InvocationCounter _invocation_counter;
1216 // Same for backedges.
1217 InvocationCounter _backedge_counter;
1218 // Number of loops and blocks is computed when compiling the first
1219 // time with C1. It is used to determine if method is trivial.
1220 short _num_loops;
1221 short _num_blocks;
1222 // Highest compile level this method has ever seen.
1223 u1 _highest_comp_level;
1224 // Same for OSR level
1225 u1 _highest_osr_comp_level;
1226 // Does this method contain anything worth profiling?
1227 bool _would_profile;
1228
1229 // Size of _data array in bytes. (Excludes header and extra_data fields.)
1230 int _data_size;
1231
1232 // Beginning of the data entries
1233 intptr_t _data[1];
1234
1235 // Helper for size computation
1236 static int compute_data_size(BytecodeStream* stream);
1237 static int bytecode_cell_count(Bytecodes::Code code);
1238 enum { no_profile_data = -1, variable_cell_count = -2 };
1239
1240 // Helper for initialization
1241 DataLayout* data_layout_at(int data_index) {
1242 assert(data_index % sizeof(intptr_t) == 0, "unaligned");
1243 return (DataLayout*) (((address)_data) + data_index);
1244 }
1245
1246 // Initialize an individual data segment. Returns the size of
1247 // the segment in bytes.
1248 int initialize_data(BytecodeStream* stream, int data_index);
1249
1250 // Helper for data_at
1251 DataLayout* limit_data_position() {
1252 return (DataLayout*)((address)data_base() + _data_size);
1253 }
1254 bool out_of_bounds(int data_index) {
1255 return data_index >= data_size();
1256 }
1257
1258 // Give each of the data entries a chance to perform specific
1259 // data initialization.
1260 void post_initialize(BytecodeStream* stream);
1261
1262 // hint accessors
1263 int hint_di() const { return _hint_di; }
1264 void set_hint_di(int di) {
1265 assert(!out_of_bounds(di), "hint_di out of bounds");
1266 _hint_di = di;
1267 }
1268 ProfileData* data_before(int bci) {
1269 // avoid SEGV on this edge case
1270 if (data_size() == 0)
1271 return NULL;
1272 int hint = hint_di();
1273 if (data_layout_at(hint)->bci() <= bci)
1274 return data_at(hint);
1275 return first_data();
1276 }
1277
1278 // What is the index of the first data entry?
1279 int first_di() { return 0; }
1280
1281 // Find or create an extra ProfileData:
1282 ProfileData* bci_to_extra_data(int bci, bool create_if_missing);
1283
1284 // return the argument info cell
1285 ArgInfoData *arg_info();
1286
1287 public:
1288 static int header_size() {
1289 return sizeof(methodDataOopDesc)/wordSize;
1290 }
1291
1292 // Compute the size of a methodDataOop before it is created.
1293 static int compute_allocation_size_in_bytes(methodHandle method);
1294 static int compute_allocation_size_in_words(methodHandle method);
1295 static int compute_extra_data_count(int data_size, int empty_bc_count);
1296
1297 // Determine if a given bytecode can have profile information.
1298 static bool bytecode_has_profile(Bytecodes::Code code) {
1299 return bytecode_cell_count(code) != no_profile_data;
1300 }
1301
1302 // Perform initialization of a new methodDataOop
1303 void initialize(methodHandle method);
1304
1305 // My size
1306 int object_size_in_bytes() { return _size; }
1307 int object_size() {
1308 return align_object_size(align_size_up(_size, BytesPerWord)/BytesPerWord);
1309 }
1310
1311 int creation_mileage() const { return _creation_mileage; }
1312 void set_creation_mileage(int x) { _creation_mileage = x; }
1313
1314 int invocation_count() {
1315 if (invocation_counter()->carry()) {
1316 return InvocationCounter::count_limit;
1317 }
1318 return invocation_counter()->count();
1319 }
1320 int backedge_count() {
1321 if (backedge_counter()->carry()) {
1322 return InvocationCounter::count_limit;
1323 }
1324 return backedge_counter()->count();
1325 }
1326
1327 InvocationCounter* invocation_counter() { return &_invocation_counter; }
1328 InvocationCounter* backedge_counter() { return &_backedge_counter; }
1329
1330 void set_would_profile(bool p) { _would_profile = p; }
1331 bool would_profile() const { return _would_profile; }
1332
1333 int highest_comp_level() { return _highest_comp_level; }
1334 void set_highest_comp_level(int level) { _highest_comp_level = level; }
1335 int highest_osr_comp_level() { return _highest_osr_comp_level; }
1336 void set_highest_osr_comp_level(int level) { _highest_osr_comp_level = level; }
1337
1338 int num_loops() const { return _num_loops; }
1339 void set_num_loops(int n) { _num_loops = n; }
1340 int num_blocks() const { return _num_blocks; }
1341 void set_num_blocks(int n) { _num_blocks = n; }
1342
1343 bool is_mature() const; // consult mileage and ProfileMaturityPercentage
1344 static int mileage_of(methodOop m);
1345
1346 // Support for interprocedural escape analysis, from Thomas Kotzmann.
1347 enum EscapeFlag {
1348 estimated = 1 << 0,
1349 return_local = 1 << 1,
1350 return_allocated = 1 << 2,
1351 allocated_escapes = 1 << 3,
1352 unknown_modified = 1 << 4
1353 };
1354
1355 intx eflags() { return _eflags; }
1356 intx arg_local() { return _arg_local; }
1357 intx arg_stack() { return _arg_stack; }
1358 intx arg_returned() { return _arg_returned; }
1359 uint arg_modified(int a) { ArgInfoData *aid = arg_info();
1360 assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
1361 return aid->arg_modified(a); }
1362
1363 void set_eflags(intx v) { _eflags = v; }
1364 void set_arg_local(intx v) { _arg_local = v; }
1365 void set_arg_stack(intx v) { _arg_stack = v; }
1366 void set_arg_returned(intx v) { _arg_returned = v; }
1367 void set_arg_modified(int a, uint v) { ArgInfoData *aid = arg_info();
1368 assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
1369
1370 aid->set_arg_modified(a, v); }
1371
1372 void clear_escape_info() { _eflags = _arg_local = _arg_stack = _arg_returned = 0; }
1373
1374 // Location and size of data area
1375 address data_base() const {
1376 return (address) _data;
1377 }
1378 int data_size() {
1379 return _data_size;
1380 }
1381
1382 // Accessors
1383 methodOop method() { return _method; }
1384
1385 // Get the data at an arbitrary (sort of) data index.
1386 ProfileData* data_at(int data_index);
1387
1388 // Walk through the data in order.
1389 ProfileData* first_data() { return data_at(first_di()); }
1390 ProfileData* next_data(ProfileData* current);
1391 bool is_valid(ProfileData* current) { return current != NULL; }
1392
1393 // Convert a dp (data pointer) to a di (data index).
1394 int dp_to_di(address dp) {
1395 return dp - ((address)_data);
1396 }
1397
1398 address di_to_dp(int di) {
1399 return (address)data_layout_at(di);
1400 }
1401
1402 // bci to di/dp conversion.
1403 address bci_to_dp(int bci);
1404 int bci_to_di(int bci) {
1405 return dp_to_di(bci_to_dp(bci));
1406 }
1407
1408 // Get the data at an arbitrary bci, or NULL if there is none.
1409 ProfileData* bci_to_data(int bci);
1410
1411 // Same, but try to create an extra_data record if one is needed:
1412 ProfileData* allocate_bci_to_data(int bci) {
1413 ProfileData* data = bci_to_data(bci);
1414 return (data != NULL) ? data : bci_to_extra_data(bci, true);
1415 }
1416
1417 // Add a handful of extra data records, for trap tracking.
1418 DataLayout* extra_data_base() { return limit_data_position(); }
1419 DataLayout* extra_data_limit() { return (DataLayout*)((address)this + object_size_in_bytes()); }
1420 int extra_data_size() { return (address)extra_data_limit()
1421 - (address)extra_data_base(); }
1422 static DataLayout* next_extra(DataLayout* dp) { return (DataLayout*)((address)dp + in_bytes(DataLayout::cell_offset(0))); }
1423
1424 // Return (uint)-1 for overflow.
1425 uint trap_count(int reason) const {
1426 assert((uint)reason < _trap_hist_limit, "oob");
1427 return (int)((_trap_hist._array[reason]+1) & _trap_hist_mask) - 1;
1428 }
1429 // For loops:
1430 static uint trap_reason_limit() { return _trap_hist_limit; }
1431 static uint trap_count_limit() { return _trap_hist_mask; }
1432 uint inc_trap_count(int reason) {
1433 // Count another trap, anywhere in this method.
1434 assert(reason >= 0, "must be single trap");
1435 if ((uint)reason < _trap_hist_limit) {
1436 uint cnt1 = 1 + _trap_hist._array[reason];
1437 if ((cnt1 & _trap_hist_mask) != 0) { // if no counter overflow...
1438 _trap_hist._array[reason] = cnt1;
1439 return cnt1;
1440 } else {
1441 return _trap_hist_mask + (++_nof_overflow_traps);
1442 }
1443 } else {
1444 // Could not represent the count in the histogram.
1445 return (++_nof_overflow_traps);
1446 }
1447 }
1448
1449 uint overflow_trap_count() const {
1450 return _nof_overflow_traps;
1451 }
1452 uint overflow_recompile_count() const {
1453 return _nof_overflow_recompiles;
1454 }
1455 void inc_overflow_recompile_count() {
1456 _nof_overflow_recompiles += 1;
1457 }
1458 uint decompile_count() const {
1459 return _nof_decompiles;
1460 }
1461 void inc_decompile_count() {
1462 _nof_decompiles += 1;
1463 if (decompile_count() > (uint)PerMethodRecompilationCutoff) {
1464 method()->set_not_compilable(CompLevel_full_optimization);
1465 }
1466 }
1467
1468 // Support for code generation
1469 static ByteSize data_offset() {
1470 return byte_offset_of(methodDataOopDesc, _data[0]);
1471 }
1472
1473 static ByteSize invocation_counter_offset() {
1474 return byte_offset_of(methodDataOopDesc, _invocation_counter);
1475 }
1476 static ByteSize backedge_counter_offset() {
1477 return byte_offset_of(methodDataOopDesc, _backedge_counter);
1478 }
1479
1480 // GC support
1481 oop* adr_method() const { return (oop*)&_method; }
1482 bool object_is_parsable() const { return _size != 0; }
1483 void set_object_is_parsable(int object_size_in_bytes) { _size = object_size_in_bytes; }
1484
1485 #ifndef PRODUCT
1486 // printing support for method data
1487 void print_data_on(outputStream* st);
1488 #endif
1489
1490 // verification
1491 void verify_data_on(outputStream* st);
1492 };