1 /*
2 * Copyright 2000-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any 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 #ifndef PRODUCT
549 void print_data_on(outputStream* st);
550 #endif
551 };
552
553 // JumpData
554 //
555 // A JumpData is used to access profiling information for a direct
556 // branch. It is a counter, used for counting the number of branches,
557 // plus a data displacement, used for realigning the data pointer to
558 // the corresponding target bci.
559 class JumpData : public ProfileData {
560 protected:
561 enum {
562 taken_off_set,
563 displacement_off_set,
564 jump_cell_count
565 };
566
567 void set_displacement(int displacement) {
568 set_int_at(displacement_off_set, displacement);
569 }
570
571 public:
572 JumpData(DataLayout* layout) : ProfileData(layout) {
573 assert(layout->tag() == DataLayout::jump_data_tag ||
574 layout->tag() == DataLayout::branch_data_tag, "wrong type");
575 }
576
577 virtual bool is_JumpData() { return true; }
578
579 static int static_cell_count() {
580 return jump_cell_count;
581 }
582
583 virtual int cell_count() {
584 return static_cell_count();
585 }
586
587 // Direct accessor
588 uint taken() {
589 return uint_at(taken_off_set);
590 }
591 // Saturating counter
592 uint inc_taken() {
593 uint cnt = taken() + 1;
594 // Did we wrap? Will compiler screw us??
595 if (cnt == 0) cnt--;
596 set_uint_at(taken_off_set, cnt);
597 return cnt;
598 }
599
600 int displacement() {
601 return int_at(displacement_off_set);
602 }
603
604 // Code generation support
605 static ByteSize taken_offset() {
606 return cell_offset(taken_off_set);
607 }
608
609 static ByteSize displacement_offset() {
610 return cell_offset(displacement_off_set);
611 }
612
613 // Specific initialization.
614 void post_initialize(BytecodeStream* stream, methodDataOop mdo);
615
616 #ifndef PRODUCT
617 void print_data_on(outputStream* st);
618 #endif
619 };
620
621 // ReceiverTypeData
622 //
623 // A ReceiverTypeData is used to access profiling information about a
624 // dynamic type check. It consists of a counter which counts the total times
625 // that the check is reached, and a series of (klassOop, count) pairs
626 // which are used to store a type profile for the receiver of the check.
627 class ReceiverTypeData : public CounterData {
628 protected:
629 enum {
630 receiver0_offset = counter_cell_count,
631 count0_offset,
632 receiver_type_row_cell_count = (count0_offset + 1) - receiver0_offset
633 };
634
635 public:
636 ReceiverTypeData(DataLayout* layout) : CounterData(layout) {
637 assert(layout->tag() == DataLayout::receiver_type_data_tag ||
638 layout->tag() == DataLayout::virtual_call_data_tag, "wrong type");
639 }
640
641 virtual bool is_ReceiverTypeData() { return true; }
642
643 static int static_cell_count() {
644 return counter_cell_count + (uint) TypeProfileWidth * receiver_type_row_cell_count;
645 }
646
647 virtual int cell_count() {
648 return static_cell_count();
649 }
650
651 // Direct accessors
652 static uint row_limit() {
653 return TypeProfileWidth;
654 }
655 static int receiver_cell_index(uint row) {
656 return receiver0_offset + row * receiver_type_row_cell_count;
657 }
658 static int receiver_count_cell_index(uint row) {
659 return count0_offset + row * receiver_type_row_cell_count;
660 }
661
662 // Get the receiver at row. The 'unchecked' version is needed by parallel old
663 // gc; it does not assert the receiver is a klass. During compaction of the
664 // perm gen, the klass may already have moved, so the is_klass() predicate
665 // would fail. The 'normal' version should be used whenever possible.
666 klassOop receiver_unchecked(uint row) {
667 assert(row < row_limit(), "oob");
668 oop recv = oop_at(receiver_cell_index(row));
669 return (klassOop)recv;
670 }
671
672 klassOop receiver(uint row) {
673 klassOop recv = receiver_unchecked(row);
674 assert(recv == NULL || ((oop)recv)->is_klass(), "wrong type");
675 return recv;
676 }
677
678 void set_receiver(uint row, oop p) {
679 assert((uint)row < row_limit(), "oob");
680 set_oop_at(receiver_cell_index(row), p);
681 }
682
683 uint receiver_count(uint row) {
684 assert(row < row_limit(), "oob");
685 return uint_at(receiver_count_cell_index(row));
686 }
687
688 void set_receiver_count(uint row, uint count) {
689 assert(row < row_limit(), "oob");
690 set_uint_at(receiver_count_cell_index(row), count);
691 }
692
693 void clear_row(uint row) {
694 assert(row < row_limit(), "oob");
695 set_receiver(row, NULL);
696 set_receiver_count(row, 0);
697 }
698
699 // Code generation support
700 static ByteSize receiver_offset(uint row) {
701 return cell_offset(receiver_cell_index(row));
702 }
703 static ByteSize receiver_count_offset(uint row) {
704 return cell_offset(receiver_count_cell_index(row));
705 }
706 static ByteSize receiver_type_data_size() {
707 return cell_offset(static_cell_count());
708 }
709
710 // GC support
711 virtual void follow_contents();
712 virtual void oop_iterate(OopClosure* blk);
713 virtual void oop_iterate_m(OopClosure* blk, MemRegion mr);
714 virtual void adjust_pointers();
715 virtual void follow_weak_refs(BoolObjectClosure* is_alive_closure);
716
717 #ifndef SERIALGC
718 // Parallel old support
719 virtual void follow_contents(ParCompactionManager* cm);
720 virtual void update_pointers();
721 virtual void update_pointers(HeapWord* beg_addr, HeapWord* end_addr);
722 #endif // SERIALGC
723
724 oop* adr_receiver(uint row) {
725 return adr_oop_at(receiver_cell_index(row));
726 }
727
728 #ifndef PRODUCT
729 void print_receiver_data_on(outputStream* st);
730 void print_data_on(outputStream* st);
731 #endif
732 };
733
734 // VirtualCallData
735 //
736 // A VirtualCallData is used to access profiling information about a
737 // virtual call. For now, it has nothing more than a ReceiverTypeData.
738 class VirtualCallData : public ReceiverTypeData {
739 public:
740 VirtualCallData(DataLayout* layout) : ReceiverTypeData(layout) {
741 assert(layout->tag() == DataLayout::virtual_call_data_tag, "wrong type");
742 }
743
744 virtual bool is_VirtualCallData() { return true; }
745
746 static int static_cell_count() {
747 // At this point we could add more profile state, e.g., for arguments.
748 // But for now it's the same size as the base record type.
749 return ReceiverTypeData::static_cell_count();
750 }
751
752 virtual int cell_count() {
753 return static_cell_count();
754 }
755
756 // Direct accessors
757 static ByteSize virtual_call_data_size() {
758 return cell_offset(static_cell_count());
759 }
760
761 #ifndef PRODUCT
762 void print_data_on(outputStream* st);
763 #endif
764 };
765
766 // RetData
767 //
768 // A RetData is used to access profiling information for a ret bytecode.
769 // It is composed of a count of the number of times that the ret has
770 // been executed, followed by a series of triples of the form
771 // (bci, count, di) which count the number of times that some bci was the
772 // target of the ret and cache a corresponding data displacement.
773 class RetData : public CounterData {
774 protected:
775 enum {
776 bci0_offset = counter_cell_count,
777 count0_offset,
778 displacement0_offset,
779 ret_row_cell_count = (displacement0_offset + 1) - bci0_offset
780 };
781
782 void set_bci(uint row, int bci) {
783 assert((uint)row < row_limit(), "oob");
784 set_int_at(bci0_offset + row * ret_row_cell_count, bci);
785 }
786 void release_set_bci(uint row, int bci) {
787 assert((uint)row < row_limit(), "oob");
788 // 'release' when setting the bci acts as a valid flag for other
789 // threads wrt bci_count and bci_displacement.
790 release_set_int_at(bci0_offset + row * ret_row_cell_count, bci);
791 }
792 void set_bci_count(uint row, uint count) {
793 assert((uint)row < row_limit(), "oob");
794 set_uint_at(count0_offset + row * ret_row_cell_count, count);
795 }
796 void set_bci_displacement(uint row, int disp) {
797 set_int_at(displacement0_offset + row * ret_row_cell_count, disp);
798 }
799
800 public:
801 RetData(DataLayout* layout) : CounterData(layout) {
802 assert(layout->tag() == DataLayout::ret_data_tag, "wrong type");
803 }
804
805 virtual bool is_RetData() { return true; }
806
807 enum {
808 no_bci = -1 // value of bci when bci1/2 are not in use.
809 };
810
811 static int static_cell_count() {
812 return counter_cell_count + (uint) BciProfileWidth * ret_row_cell_count;
813 }
814
815 virtual int cell_count() {
816 return static_cell_count();
817 }
818
819 static uint row_limit() {
820 return BciProfileWidth;
821 }
822 static int bci_cell_index(uint row) {
823 return bci0_offset + row * ret_row_cell_count;
824 }
825 static int bci_count_cell_index(uint row) {
826 return count0_offset + row * ret_row_cell_count;
827 }
828 static int bci_displacement_cell_index(uint row) {
829 return displacement0_offset + row * ret_row_cell_count;
830 }
831
832 // Direct accessors
833 int bci(uint row) {
834 return int_at(bci_cell_index(row));
835 }
836 uint bci_count(uint row) {
837 return uint_at(bci_count_cell_index(row));
838 }
839 int bci_displacement(uint row) {
840 return int_at(bci_displacement_cell_index(row));
841 }
842
843 // Interpreter Runtime support
844 address fixup_ret(int return_bci, methodDataHandle mdo);
845
846 // Code generation support
847 static ByteSize bci_offset(uint row) {
848 return cell_offset(bci_cell_index(row));
849 }
850 static ByteSize bci_count_offset(uint row) {
851 return cell_offset(bci_count_cell_index(row));
852 }
853 static ByteSize bci_displacement_offset(uint row) {
854 return cell_offset(bci_displacement_cell_index(row));
855 }
856
857 // Specific initialization.
858 void post_initialize(BytecodeStream* stream, methodDataOop mdo);
859
860 #ifndef PRODUCT
861 void print_data_on(outputStream* st);
862 #endif
863 };
864
865 // BranchData
866 //
867 // A BranchData is used to access profiling data for a two-way branch.
868 // It consists of taken and not_taken counts as well as a data displacement
869 // for the taken case.
870 class BranchData : public JumpData {
871 protected:
872 enum {
873 not_taken_off_set = jump_cell_count,
874 branch_cell_count
875 };
876
877 void set_displacement(int displacement) {
878 set_int_at(displacement_off_set, displacement);
879 }
880
881 public:
882 BranchData(DataLayout* layout) : JumpData(layout) {
883 assert(layout->tag() == DataLayout::branch_data_tag, "wrong type");
884 }
885
886 virtual bool is_BranchData() { return true; }
887
888 static int static_cell_count() {
889 return branch_cell_count;
890 }
891
892 virtual int cell_count() {
893 return static_cell_count();
894 }
895
896 // Direct accessor
897 uint not_taken() {
898 return uint_at(not_taken_off_set);
899 }
900
901 uint inc_not_taken() {
902 uint cnt = not_taken() + 1;
903 // Did we wrap? Will compiler screw us??
904 if (cnt == 0) cnt--;
905 set_uint_at(not_taken_off_set, cnt);
906 return cnt;
907 }
908
909 // Code generation support
910 static ByteSize not_taken_offset() {
911 return cell_offset(not_taken_off_set);
912 }
913 static ByteSize branch_data_size() {
914 return cell_offset(branch_cell_count);
915 }
916
917 // Specific initialization.
918 void post_initialize(BytecodeStream* stream, methodDataOop mdo);
919
920 #ifndef PRODUCT
921 void print_data_on(outputStream* st);
922 #endif
923 };
924
925 // ArrayData
926 //
927 // A ArrayData is a base class for accessing profiling data which does
928 // not have a statically known size. It consists of an array length
929 // and an array start.
930 class ArrayData : public ProfileData {
931 protected:
932 friend class DataLayout;
933
934 enum {
935 array_len_off_set,
936 array_start_off_set
937 };
938
939 uint array_uint_at(int index) {
940 int aindex = index + array_start_off_set;
941 return uint_at(aindex);
942 }
943 int array_int_at(int index) {
944 int aindex = index + array_start_off_set;
945 return int_at(aindex);
946 }
947 oop array_oop_at(int index) {
948 int aindex = index + array_start_off_set;
949 return oop_at(aindex);
950 }
951 void array_set_int_at(int index, int value) {
952 int aindex = index + array_start_off_set;
953 set_int_at(aindex, value);
954 }
955
956 // Code generation support for subclasses.
957 static ByteSize array_element_offset(int index) {
958 return cell_offset(array_start_off_set + index);
959 }
960
961 public:
962 ArrayData(DataLayout* layout) : ProfileData(layout) {}
963
964 virtual bool is_ArrayData() { return true; }
965
966 static int static_cell_count() {
967 return -1;
968 }
969
970 int array_len() {
971 return int_at_unchecked(array_len_off_set);
972 }
973
974 virtual int cell_count() {
975 return array_len() + 1;
976 }
977
978 // Code generation support
979 static ByteSize array_len_offset() {
980 return cell_offset(array_len_off_set);
981 }
982 static ByteSize array_start_offset() {
983 return cell_offset(array_start_off_set);
984 }
985 };
986
987 // MultiBranchData
988 //
989 // A MultiBranchData is used to access profiling information for
990 // a multi-way branch (*switch bytecodes). It consists of a series
991 // of (count, displacement) pairs, which count the number of times each
992 // case was taken and specify the data displacment for each branch target.
993 class MultiBranchData : public ArrayData {
994 protected:
995 enum {
996 default_count_off_set,
997 default_disaplacement_off_set,
998 case_array_start
999 };
1000 enum {
1001 relative_count_off_set,
1002 relative_displacement_off_set,
1003 per_case_cell_count
1004 };
1005
1006 void set_default_displacement(int displacement) {
1007 array_set_int_at(default_disaplacement_off_set, displacement);
1008 }
1009 void set_displacement_at(int index, int displacement) {
1010 array_set_int_at(case_array_start +
1011 index * per_case_cell_count +
1012 relative_displacement_off_set,
1013 displacement);
1014 }
1015
1016 public:
1017 MultiBranchData(DataLayout* layout) : ArrayData(layout) {
1018 assert(layout->tag() == DataLayout::multi_branch_data_tag, "wrong type");
1019 }
1020
1021 virtual bool is_MultiBranchData() { return true; }
1022
1023 static int compute_cell_count(BytecodeStream* stream);
1024
1025 int number_of_cases() {
1026 int alen = array_len() - 2; // get rid of default case here.
1027 assert(alen % per_case_cell_count == 0, "must be even");
1028 return (alen / per_case_cell_count);
1029 }
1030
1031 uint default_count() {
1032 return array_uint_at(default_count_off_set);
1033 }
1034 int default_displacement() {
1035 return array_int_at(default_disaplacement_off_set);
1036 }
1037
1038 uint count_at(int index) {
1039 return array_uint_at(case_array_start +
1040 index * per_case_cell_count +
1041 relative_count_off_set);
1042 }
1043 int displacement_at(int index) {
1044 return array_int_at(case_array_start +
1045 index * per_case_cell_count +
1046 relative_displacement_off_set);
1047 }
1048
1049 // Code generation support
1050 static ByteSize default_count_offset() {
1051 return array_element_offset(default_count_off_set);
1052 }
1053 static ByteSize default_displacement_offset() {
1054 return array_element_offset(default_disaplacement_off_set);
1055 }
1056 static ByteSize case_count_offset(int index) {
1057 return case_array_offset() +
1058 (per_case_size() * index) +
1059 relative_count_offset();
1060 }
1061 static ByteSize case_array_offset() {
1062 return array_element_offset(case_array_start);
1063 }
1064 static ByteSize per_case_size() {
1065 return in_ByteSize(per_case_cell_count) * cell_size;
1066 }
1067 static ByteSize relative_count_offset() {
1068 return in_ByteSize(relative_count_off_set) * cell_size;
1069 }
1070 static ByteSize relative_displacement_offset() {
1071 return in_ByteSize(relative_displacement_off_set) * cell_size;
1072 }
1073
1074 // Specific initialization.
1075 void post_initialize(BytecodeStream* stream, methodDataOop mdo);
1076
1077 #ifndef PRODUCT
1078 void print_data_on(outputStream* st);
1079 #endif
1080 };
1081
1082 class ArgInfoData : public ArrayData {
1083
1084 public:
1085 ArgInfoData(DataLayout* layout) : ArrayData(layout) {
1086 assert(layout->tag() == DataLayout::arg_info_data_tag, "wrong type");
1087 }
1088
1089 virtual bool is_ArgInfoData() { return true; }
1090
1091
1092 int number_of_args() {
1093 return array_len();
1094 }
1095
1096 uint arg_modified(int arg) {
1097 return array_uint_at(arg);
1098 }
1099
1100 void set_arg_modified(int arg, uint val) {
1101 array_set_int_at(arg, val);
1102 }
1103
1104 #ifndef PRODUCT
1105 void print_data_on(outputStream* st);
1106 #endif
1107 };
1108
1109 // methodDataOop
1110 //
1111 // A methodDataOop holds information which has been collected about
1112 // a method. Its layout looks like this:
1113 //
1114 // -----------------------------
1115 // | header |
1116 // | klass |
1117 // -----------------------------
1118 // | method |
1119 // | size of the methodDataOop |
1120 // -----------------------------
1121 // | Data entries... |
1122 // | (variable size) |
1123 // | |
1124 // . .
1125 // . .
1126 // . .
1127 // | |
1128 // -----------------------------
1129 //
1130 // The data entry area is a heterogeneous array of DataLayouts. Each
1131 // DataLayout in the array corresponds to a specific bytecode in the
1132 // method. The entries in the array are sorted by the corresponding
1133 // bytecode. Access to the data is via resource-allocated ProfileData,
1134 // which point to the underlying blocks of DataLayout structures.
1135 //
1136 // During interpretation, if profiling in enabled, the interpreter
1137 // maintains a method data pointer (mdp), which points at the entry
1138 // in the array corresponding to the current bci. In the course of
1139 // intepretation, when a bytecode is encountered that has profile data
1140 // associated with it, the entry pointed to by mdp is updated, then the
1141 // mdp is adjusted to point to the next appropriate DataLayout. If mdp
1142 // is NULL to begin with, the interpreter assumes that the current method
1143 // is not (yet) being profiled.
1144 //
1145 // In methodDataOop parlance, "dp" is a "data pointer", the actual address
1146 // of a DataLayout element. A "di" is a "data index", the offset in bytes
1147 // from the base of the data entry array. A "displacement" is the byte offset
1148 // in certain ProfileData objects that indicate the amount the mdp must be
1149 // adjusted in the event of a change in control flow.
1150 //
1151
1152 class methodDataOopDesc : public oopDesc {
1153 friend class VMStructs;
1154 private:
1155 friend class ProfileData;
1156
1157 // Back pointer to the methodOop
1158 methodOop _method;
1159
1160 // Size of this oop in bytes
1161 int _size;
1162
1163 // Cached hint for bci_to_dp and bci_to_data
1164 int _hint_di;
1165
1166 // Whole-method sticky bits and flags
1167 public:
1168 enum {
1169 _trap_hist_limit = 16, // decoupled from Deoptimization::Reason_LIMIT
1170 _trap_hist_mask = max_jubyte,
1171 _extra_data_count = 4 // extra DataLayout headers, for trap history
1172 }; // Public flag values
1173 private:
1174 uint _nof_decompiles; // count of all nmethod removals
1175 uint _nof_overflow_recompiles; // recompile count, excluding recomp. bits
1176 uint _nof_overflow_traps; // trap count, excluding _trap_hist
1177 union {
1178 intptr_t _align;
1179 u1 _array[_trap_hist_limit];
1180 } _trap_hist;
1181
1182 // Support for interprocedural escape analysis, from Thomas Kotzmann.
1183 intx _eflags; // flags on escape information
1184 intx _arg_local; // bit set of non-escaping arguments
1185 intx _arg_stack; // bit set of stack-allocatable arguments
1186 intx _arg_returned; // bit set of returned arguments
1187
1188 int _creation_mileage; // method mileage at MDO creation
1189
1190 // Size of _data array in bytes. (Excludes header and extra_data fields.)
1191 int _data_size;
1192
1193 // Beginning of the data entries
1194 intptr_t _data[1];
1195
1196 // Helper for size computation
1197 static int compute_data_size(BytecodeStream* stream);
1198 static int bytecode_cell_count(Bytecodes::Code code);
1199 enum { no_profile_data = -1, variable_cell_count = -2 };
1200
1201 // Helper for initialization
1202 DataLayout* data_layout_at(int data_index) {
1203 assert(data_index % sizeof(intptr_t) == 0, "unaligned");
1204 return (DataLayout*) (((address)_data) + data_index);
1205 }
1206
1207 // Initialize an individual data segment. Returns the size of
1208 // the segment in bytes.
1209 int initialize_data(BytecodeStream* stream, int data_index);
1210
1211 // Helper for data_at
1212 DataLayout* limit_data_position() {
1213 return (DataLayout*)((address)data_base() + _data_size);
1214 }
1215 bool out_of_bounds(int data_index) {
1216 return data_index >= data_size();
1217 }
1218
1219 // Give each of the data entries a chance to perform specific
1220 // data initialization.
1221 void post_initialize(BytecodeStream* stream);
1222
1223 // hint accessors
1224 int hint_di() const { return _hint_di; }
1225 void set_hint_di(int di) {
1226 assert(!out_of_bounds(di), "hint_di out of bounds");
1227 _hint_di = di;
1228 }
1229 ProfileData* data_before(int bci) {
1230 // avoid SEGV on this edge case
1231 if (data_size() == 0)
1232 return NULL;
1233 int hint = hint_di();
1234 if (data_layout_at(hint)->bci() <= bci)
1235 return data_at(hint);
1236 return first_data();
1237 }
1238
1239 // What is the index of the first data entry?
1240 int first_di() { return 0; }
1241
1242 // Find or create an extra ProfileData:
1243 ProfileData* bci_to_extra_data(int bci, bool create_if_missing);
1244
1245 // return the argument info cell
1246 ArgInfoData *arg_info();
1247
1248 public:
1249 static int header_size() {
1250 return sizeof(methodDataOopDesc)/wordSize;
1251 }
1252
1253 // Compute the size of a methodDataOop before it is created.
1254 static int compute_allocation_size_in_bytes(methodHandle method);
1255 static int compute_allocation_size_in_words(methodHandle method);
1256 static int compute_extra_data_count(int data_size, int empty_bc_count);
1257
1258 // Determine if a given bytecode can have profile information.
1259 static bool bytecode_has_profile(Bytecodes::Code code) {
1260 return bytecode_cell_count(code) != no_profile_data;
1261 }
1262
1263 // Perform initialization of a new methodDataOop
1264 void initialize(methodHandle method);
1265
1266 // My size
1267 int object_size_in_bytes() { return _size; }
1268 int object_size() {
1269 return align_object_size(align_size_up(_size, BytesPerWord)/BytesPerWord);
1270 }
1271
1272 int creation_mileage() const { return _creation_mileage; }
1273 void set_creation_mileage(int x) { _creation_mileage = x; }
1274 bool is_mature() const; // consult mileage and ProfileMaturityPercentage
1275 static int mileage_of(methodOop m);
1276
1277 // Support for interprocedural escape analysis, from Thomas Kotzmann.
1278 enum EscapeFlag {
1279 estimated = 1 << 0,
1280 return_local = 1 << 1,
1281 return_allocated = 1 << 2,
1282 allocated_escapes = 1 << 3,
1283 unknown_modified = 1 << 4
1284 };
1285
1286 intx eflags() { return _eflags; }
1287 intx arg_local() { return _arg_local; }
1288 intx arg_stack() { return _arg_stack; }
1289 intx arg_returned() { return _arg_returned; }
1290 uint arg_modified(int a) { ArgInfoData *aid = arg_info();
1291 assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
1292 return aid->arg_modified(a); }
1293
1294 void set_eflags(intx v) { _eflags = v; }
1295 void set_arg_local(intx v) { _arg_local = v; }
1296 void set_arg_stack(intx v) { _arg_stack = v; }
1297 void set_arg_returned(intx v) { _arg_returned = v; }
1298 void set_arg_modified(int a, uint v) { ArgInfoData *aid = arg_info();
1299 assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
1300
1301 aid->set_arg_modified(a, v); }
1302
1303 void clear_escape_info() { _eflags = _arg_local = _arg_stack = _arg_returned = 0; }
1304
1305 // Location and size of data area
1306 address data_base() const {
1307 return (address) _data;
1308 }
1309 int data_size() {
1310 return _data_size;
1311 }
1312
1313 // Accessors
1314 methodOop method() { return _method; }
1315
1316 // Get the data at an arbitrary (sort of) data index.
1317 ProfileData* data_at(int data_index);
1318
1319 // Walk through the data in order.
1320 ProfileData* first_data() { return data_at(first_di()); }
1321 ProfileData* next_data(ProfileData* current);
1322 bool is_valid(ProfileData* current) { return current != NULL; }
1323
1324 // Convert a dp (data pointer) to a di (data index).
1325 int dp_to_di(address dp) {
1326 return dp - ((address)_data);
1327 }
1328
1329 address di_to_dp(int di) {
1330 return (address)data_layout_at(di);
1331 }
1332
1333 // bci to di/dp conversion.
1334 address bci_to_dp(int bci);
1335 int bci_to_di(int bci) {
1336 return dp_to_di(bci_to_dp(bci));
1337 }
1338
1339 // Get the data at an arbitrary bci, or NULL if there is none.
1340 ProfileData* bci_to_data(int bci);
1341
1342 // Same, but try to create an extra_data record if one is needed:
1343 ProfileData* allocate_bci_to_data(int bci) {
1344 ProfileData* data = bci_to_data(bci);
1345 return (data != NULL) ? data : bci_to_extra_data(bci, true);
1346 }
1347
1348 // Add a handful of extra data records, for trap tracking.
1349 DataLayout* extra_data_base() { return limit_data_position(); }
1350 DataLayout* extra_data_limit() { return (DataLayout*)((address)this + object_size_in_bytes()); }
1351 int extra_data_size() { return (address)extra_data_limit()
1352 - (address)extra_data_base(); }
1353 static DataLayout* next_extra(DataLayout* dp) { return (DataLayout*)((address)dp + in_bytes(DataLayout::cell_offset(0))); }
1354
1355 // Return (uint)-1 for overflow.
1356 uint trap_count(int reason) const {
1357 assert((uint)reason < _trap_hist_limit, "oob");
1358 return (int)((_trap_hist._array[reason]+1) & _trap_hist_mask) - 1;
1359 }
1360 // For loops:
1361 static uint trap_reason_limit() { return _trap_hist_limit; }
1362 static uint trap_count_limit() { return _trap_hist_mask; }
1363 uint inc_trap_count(int reason) {
1364 // Count another trap, anywhere in this method.
1365 assert(reason >= 0, "must be single trap");
1366 if ((uint)reason < _trap_hist_limit) {
1367 uint cnt1 = 1 + _trap_hist._array[reason];
1368 if ((cnt1 & _trap_hist_mask) != 0) { // if no counter overflow...
1369 _trap_hist._array[reason] = cnt1;
1370 return cnt1;
1371 } else {
1372 return _trap_hist_mask + (++_nof_overflow_traps);
1373 }
1374 } else {
1375 // Could not represent the count in the histogram.
1376 return (++_nof_overflow_traps);
1377 }
1378 }
1379
1380 uint overflow_trap_count() const {
1381 return _nof_overflow_traps;
1382 }
1383 uint overflow_recompile_count() const {
1384 return _nof_overflow_recompiles;
1385 }
1386 void inc_overflow_recompile_count() {
1387 _nof_overflow_recompiles += 1;
1388 }
1389 uint decompile_count() const {
1390 return _nof_decompiles;
1391 }
1392 void inc_decompile_count() {
1393 _nof_decompiles += 1;
1394 }
1395
1396 // Support for code generation
1397 static ByteSize data_offset() {
1398 return byte_offset_of(methodDataOopDesc, _data[0]);
1399 }
1400
1401 // GC support
1402 oop* adr_method() const { return (oop*)&_method; }
1403 bool object_is_parsable() const { return _size != 0; }
1404 void set_object_is_parsable(int object_size_in_bytes) { _size = object_size_in_bytes; }
1405
1406 #ifndef PRODUCT
1407 // printing support for method data
1408 void print_data_on(outputStream* st);
1409 #endif
1410
1411 // verification
1412 void verify_data_on(outputStream* st);
1413 };