Fri, 28 Mar 2008 11:52:29 -0700
6680665: bytecode Escape Analyzer produces incorrect escape information for methods without oop arguments
Summary: bcEscapeAnalyzer does not analyze methods with no oop arguments.
Reviewed-by: rasbold
1 /*
2 * Copyright 2000-2007 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 */
25 class BytecodeStream;
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.
58 // DataLayout
59 //
60 // Overlay for generic profiling data.
61 class DataLayout VALUE_OBJ_CLASS_SPEC {
62 private:
63 // Every data layout begins with a header. This header
64 // contains a tag, which is used to indicate the size/layout
65 // of the data, 4 bits of flags, which can be used in any way,
66 // 4 bits of trap history (none/one reason/many reasons),
67 // and a bci, which is used to tie this piece of data to a
68 // specific bci in the bytecodes.
69 union {
70 intptr_t _bits;
71 struct {
72 u1 _tag;
73 u1 _flags;
74 u2 _bci;
75 } _struct;
76 } _header;
78 // The data layout has an arbitrary number of cells, each sized
79 // to accomodate a pointer or an integer.
80 intptr_t _cells[1];
82 // Some types of data layouts need a length field.
83 static bool needs_array_len(u1 tag);
85 public:
86 enum {
87 counter_increment = 1
88 };
90 enum {
91 cell_size = sizeof(intptr_t)
92 };
94 // Tag values
95 enum {
96 no_tag,
97 bit_data_tag,
98 counter_data_tag,
99 jump_data_tag,
100 receiver_type_data_tag,
101 virtual_call_data_tag,
102 ret_data_tag,
103 branch_data_tag,
104 multi_branch_data_tag,
105 arg_info_data_tag
106 };
108 enum {
109 // The _struct._flags word is formatted as [trap_state:4 | flags:4].
110 // The trap state breaks down further as [recompile:1 | reason:3].
111 // This further breakdown is defined in deoptimization.cpp.
112 // See Deoptimization::trap_state_reason for an assert that
113 // trap_bits is big enough to hold reasons < Reason_RECORDED_LIMIT.
114 //
115 // The trap_state is collected only if ProfileTraps is true.
116 trap_bits = 1+3, // 3: enough to distinguish [0..Reason_RECORDED_LIMIT].
117 trap_shift = BitsPerByte - trap_bits,
118 trap_mask = right_n_bits(trap_bits),
119 trap_mask_in_place = (trap_mask << trap_shift),
120 flag_limit = trap_shift,
121 flag_mask = right_n_bits(flag_limit),
122 first_flag = 0
123 };
125 // Size computation
126 static int header_size_in_bytes() {
127 return cell_size;
128 }
129 static int header_size_in_cells() {
130 return 1;
131 }
133 static int compute_size_in_bytes(int cell_count) {
134 return header_size_in_bytes() + cell_count * cell_size;
135 }
137 // Initialization
138 void initialize(u1 tag, u2 bci, int cell_count);
140 // Accessors
141 u1 tag() {
142 return _header._struct._tag;
143 }
145 // Return a few bits of trap state. Range is [0..trap_mask].
146 // The state tells if traps with zero, one, or many reasons have occurred.
147 // It also tells whether zero or many recompilations have occurred.
148 // The associated trap histogram in the MDO itself tells whether
149 // traps are common or not. If a BCI shows that a trap X has
150 // occurred, and the MDO shows N occurrences of X, we make the
151 // simplifying assumption that all N occurrences can be blamed
152 // on that BCI.
153 int trap_state() {
154 return ((_header._struct._flags >> trap_shift) & trap_mask);
155 }
157 void set_trap_state(int new_state) {
158 assert(ProfileTraps, "used only under +ProfileTraps");
159 uint old_flags = (_header._struct._flags & flag_mask);
160 _header._struct._flags = (new_state << trap_shift) | old_flags;
161 assert(trap_state() == new_state, "sanity");
162 }
164 u1 flags() {
165 return _header._struct._flags;
166 }
168 u2 bci() {
169 return _header._struct._bci;
170 }
172 void set_header(intptr_t value) {
173 _header._bits = value;
174 }
175 void release_set_header(intptr_t value) {
176 OrderAccess::release_store_ptr(&_header._bits, value);
177 }
178 intptr_t header() {
179 return _header._bits;
180 }
181 void set_cell_at(int index, intptr_t value) {
182 _cells[index] = value;
183 }
184 void release_set_cell_at(int index, intptr_t value) {
185 OrderAccess::release_store_ptr(&_cells[index], value);
186 }
187 intptr_t cell_at(int index) {
188 return _cells[index];
189 }
190 intptr_t* adr_cell_at(int index) {
191 return &_cells[index];
192 }
193 oop* adr_oop_at(int index) {
194 return (oop*)&(_cells[index]);
195 }
197 void set_flag_at(int flag_number) {
198 assert(flag_number < flag_limit, "oob");
199 _header._struct._flags |= (0x1 << flag_number);
200 }
201 bool flag_at(int flag_number) {
202 assert(flag_number < flag_limit, "oob");
203 return (_header._struct._flags & (0x1 << flag_number)) != 0;
204 }
206 // Low-level support for code generation.
207 static ByteSize header_offset() {
208 return byte_offset_of(DataLayout, _header);
209 }
210 static ByteSize tag_offset() {
211 return byte_offset_of(DataLayout, _header._struct._tag);
212 }
213 static ByteSize flags_offset() {
214 return byte_offset_of(DataLayout, _header._struct._flags);
215 }
216 static ByteSize bci_offset() {
217 return byte_offset_of(DataLayout, _header._struct._bci);
218 }
219 static ByteSize cell_offset(int index) {
220 return byte_offset_of(DataLayout, _cells[index]);
221 }
222 // Return a value which, when or-ed as a byte into _flags, sets the flag.
223 static int flag_number_to_byte_constant(int flag_number) {
224 assert(0 <= flag_number && flag_number < flag_limit, "oob");
225 DataLayout temp; temp.set_header(0);
226 temp.set_flag_at(flag_number);
227 return temp._header._struct._flags;
228 }
229 // Return a value which, when or-ed as a word into _header, sets the flag.
230 static intptr_t flag_mask_to_header_mask(int byte_constant) {
231 DataLayout temp; temp.set_header(0);
232 temp._header._struct._flags = byte_constant;
233 return temp._header._bits;
234 }
235 };
238 // ProfileData class hierarchy
239 class ProfileData;
240 class BitData;
241 class CounterData;
242 class ReceiverTypeData;
243 class VirtualCallData;
244 class RetData;
245 class JumpData;
246 class BranchData;
247 class ArrayData;
248 class MultiBranchData;
249 class ArgInfoData;
252 // ProfileData
253 //
254 // A ProfileData object is created to refer to a section of profiling
255 // data in a structured way.
256 class ProfileData : public ResourceObj {
257 private:
258 #ifndef PRODUCT
259 enum {
260 tab_width_one = 16,
261 tab_width_two = 36
262 };
263 #endif // !PRODUCT
265 // This is a pointer to a section of profiling data.
266 DataLayout* _data;
268 protected:
269 DataLayout* data() { return _data; }
271 enum {
272 cell_size = DataLayout::cell_size
273 };
275 public:
276 // How many cells are in this?
277 virtual int cell_count() {
278 ShouldNotReachHere();
279 return -1;
280 }
282 // Return the size of this data.
283 int size_in_bytes() {
284 return DataLayout::compute_size_in_bytes(cell_count());
285 }
287 protected:
288 // Low-level accessors for underlying data
289 void set_intptr_at(int index, intptr_t value) {
290 assert(0 <= index && index < cell_count(), "oob");
291 data()->set_cell_at(index, value);
292 }
293 void release_set_intptr_at(int index, intptr_t value) {
294 assert(0 <= index && index < cell_count(), "oob");
295 data()->release_set_cell_at(index, value);
296 }
297 intptr_t intptr_at(int index) {
298 assert(0 <= index && index < cell_count(), "oob");
299 return data()->cell_at(index);
300 }
301 void set_uint_at(int index, uint value) {
302 set_intptr_at(index, (intptr_t) value);
303 }
304 void release_set_uint_at(int index, uint value) {
305 release_set_intptr_at(index, (intptr_t) value);
306 }
307 uint uint_at(int index) {
308 return (uint)intptr_at(index);
309 }
310 void set_int_at(int index, int value) {
311 set_intptr_at(index, (intptr_t) value);
312 }
313 void release_set_int_at(int index, int value) {
314 release_set_intptr_at(index, (intptr_t) value);
315 }
316 int int_at(int index) {
317 return (int)intptr_at(index);
318 }
319 int int_at_unchecked(int index) {
320 return (int)data()->cell_at(index);
321 }
322 void set_oop_at(int index, oop value) {
323 set_intptr_at(index, (intptr_t) value);
324 }
325 oop oop_at(int index) {
326 return (oop)intptr_at(index);
327 }
328 oop* adr_oop_at(int index) {
329 assert(0 <= index && index < cell_count(), "oob");
330 return data()->adr_oop_at(index);
331 }
333 void set_flag_at(int flag_number) {
334 data()->set_flag_at(flag_number);
335 }
336 bool flag_at(int flag_number) {
337 return data()->flag_at(flag_number);
338 }
340 // two convenient imports for use by subclasses:
341 static ByteSize cell_offset(int index) {
342 return DataLayout::cell_offset(index);
343 }
344 static int flag_number_to_byte_constant(int flag_number) {
345 return DataLayout::flag_number_to_byte_constant(flag_number);
346 }
348 ProfileData(DataLayout* data) {
349 _data = data;
350 }
352 public:
353 // Constructor for invalid ProfileData.
354 ProfileData();
356 u2 bci() {
357 return data()->bci();
358 }
360 address dp() {
361 return (address)_data;
362 }
364 int trap_state() {
365 return data()->trap_state();
366 }
367 void set_trap_state(int new_state) {
368 data()->set_trap_state(new_state);
369 }
371 // Type checking
372 virtual bool is_BitData() { return false; }
373 virtual bool is_CounterData() { return false; }
374 virtual bool is_JumpData() { return false; }
375 virtual bool is_ReceiverTypeData(){ return false; }
376 virtual bool is_VirtualCallData() { return false; }
377 virtual bool is_RetData() { return false; }
378 virtual bool is_BranchData() { return false; }
379 virtual bool is_ArrayData() { return false; }
380 virtual bool is_MultiBranchData() { return false; }
381 virtual bool is_ArgInfoData() { return false; }
384 BitData* as_BitData() {
385 assert(is_BitData(), "wrong type");
386 return is_BitData() ? (BitData*) this : NULL;
387 }
388 CounterData* as_CounterData() {
389 assert(is_CounterData(), "wrong type");
390 return is_CounterData() ? (CounterData*) this : NULL;
391 }
392 JumpData* as_JumpData() {
393 assert(is_JumpData(), "wrong type");
394 return is_JumpData() ? (JumpData*) this : NULL;
395 }
396 ReceiverTypeData* as_ReceiverTypeData() {
397 assert(is_ReceiverTypeData(), "wrong type");
398 return is_ReceiverTypeData() ? (ReceiverTypeData*)this : NULL;
399 }
400 VirtualCallData* as_VirtualCallData() {
401 assert(is_VirtualCallData(), "wrong type");
402 return is_VirtualCallData() ? (VirtualCallData*)this : NULL;
403 }
404 RetData* as_RetData() {
405 assert(is_RetData(), "wrong type");
406 return is_RetData() ? (RetData*) this : NULL;
407 }
408 BranchData* as_BranchData() {
409 assert(is_BranchData(), "wrong type");
410 return is_BranchData() ? (BranchData*) this : NULL;
411 }
412 ArrayData* as_ArrayData() {
413 assert(is_ArrayData(), "wrong type");
414 return is_ArrayData() ? (ArrayData*) this : NULL;
415 }
416 MultiBranchData* as_MultiBranchData() {
417 assert(is_MultiBranchData(), "wrong type");
418 return is_MultiBranchData() ? (MultiBranchData*)this : NULL;
419 }
420 ArgInfoData* as_ArgInfoData() {
421 assert(is_ArgInfoData(), "wrong type");
422 return is_ArgInfoData() ? (ArgInfoData*)this : NULL;
423 }
426 // Subclass specific initialization
427 virtual void post_initialize(BytecodeStream* stream, methodDataOop mdo) {}
429 // GC support
430 virtual void follow_contents() {}
431 virtual void oop_iterate(OopClosure* blk) {}
432 virtual void oop_iterate_m(OopClosure* blk, MemRegion mr) {}
433 virtual void adjust_pointers() {}
435 #ifndef SERIALGC
436 // Parallel old support
437 virtual void follow_contents(ParCompactionManager* cm) {}
438 virtual void update_pointers() {}
439 virtual void update_pointers(HeapWord* beg_addr, HeapWord* end_addr) {}
440 #endif // SERIALGC
442 // CI translation: ProfileData can represent both MethodDataOop data
443 // as well as CIMethodData data. This function is provided for translating
444 // an oop in a ProfileData to the ci equivalent. Generally speaking,
445 // most ProfileData don't require any translation, so we provide the null
446 // translation here, and the required translators are in the ci subclasses.
447 virtual void translate_from(ProfileData* data) {}
449 virtual void print_data_on(outputStream* st) {
450 ShouldNotReachHere();
451 }
453 #ifndef PRODUCT
454 void print_shared(outputStream* st, const char* name);
455 void tab(outputStream* st);
456 #endif
457 };
459 // BitData
460 //
461 // A BitData holds a flag or two in its header.
462 class BitData : public ProfileData {
463 protected:
464 enum {
465 // null_seen:
466 // saw a null operand (cast/aastore/instanceof)
467 null_seen_flag = DataLayout::first_flag + 0
468 };
469 enum { bit_cell_count = 0 }; // no additional data fields needed.
470 public:
471 BitData(DataLayout* layout) : ProfileData(layout) {
472 }
474 virtual bool is_BitData() { return true; }
476 static int static_cell_count() {
477 return bit_cell_count;
478 }
480 virtual int cell_count() {
481 return static_cell_count();
482 }
484 // Accessor
486 // The null_seen flag bit is specially known to the interpreter.
487 // Consulting it allows the compiler to avoid setting up null_check traps.
488 bool null_seen() { return flag_at(null_seen_flag); }
489 void set_null_seen() { set_flag_at(null_seen_flag); }
492 // Code generation support
493 static int null_seen_byte_constant() {
494 return flag_number_to_byte_constant(null_seen_flag);
495 }
497 static ByteSize bit_data_size() {
498 return cell_offset(bit_cell_count);
499 }
501 #ifndef PRODUCT
502 void print_data_on(outputStream* st);
503 #endif
504 };
506 // CounterData
507 //
508 // A CounterData corresponds to a simple counter.
509 class CounterData : public BitData {
510 protected:
511 enum {
512 count_off,
513 counter_cell_count
514 };
515 public:
516 CounterData(DataLayout* layout) : BitData(layout) {}
518 virtual bool is_CounterData() { return true; }
520 static int static_cell_count() {
521 return counter_cell_count;
522 }
524 virtual int cell_count() {
525 return static_cell_count();
526 }
528 // Direct accessor
529 uint count() {
530 return uint_at(count_off);
531 }
533 // Code generation support
534 static ByteSize count_offset() {
535 return cell_offset(count_off);
536 }
537 static ByteSize counter_data_size() {
538 return cell_offset(counter_cell_count);
539 }
541 #ifndef PRODUCT
542 void print_data_on(outputStream* st);
543 #endif
544 };
546 // JumpData
547 //
548 // A JumpData is used to access profiling information for a direct
549 // branch. It is a counter, used for counting the number of branches,
550 // plus a data displacement, used for realigning the data pointer to
551 // the corresponding target bci.
552 class JumpData : public ProfileData {
553 protected:
554 enum {
555 taken_off_set,
556 displacement_off_set,
557 jump_cell_count
558 };
560 void set_displacement(int displacement) {
561 set_int_at(displacement_off_set, displacement);
562 }
564 public:
565 JumpData(DataLayout* layout) : ProfileData(layout) {
566 assert(layout->tag() == DataLayout::jump_data_tag ||
567 layout->tag() == DataLayout::branch_data_tag, "wrong type");
568 }
570 virtual bool is_JumpData() { return true; }
572 static int static_cell_count() {
573 return jump_cell_count;
574 }
576 virtual int cell_count() {
577 return static_cell_count();
578 }
580 // Direct accessor
581 uint taken() {
582 return uint_at(taken_off_set);
583 }
584 // Saturating counter
585 uint inc_taken() {
586 uint cnt = taken() + 1;
587 // Did we wrap? Will compiler screw us??
588 if (cnt == 0) cnt--;
589 set_uint_at(taken_off_set, cnt);
590 return cnt;
591 }
593 int displacement() {
594 return int_at(displacement_off_set);
595 }
597 // Code generation support
598 static ByteSize taken_offset() {
599 return cell_offset(taken_off_set);
600 }
602 static ByteSize displacement_offset() {
603 return cell_offset(displacement_off_set);
604 }
606 // Specific initialization.
607 void post_initialize(BytecodeStream* stream, methodDataOop mdo);
609 #ifndef PRODUCT
610 void print_data_on(outputStream* st);
611 #endif
612 };
614 // ReceiverTypeData
615 //
616 // A ReceiverTypeData is used to access profiling information about a
617 // dynamic type check. It consists of a counter which counts the total times
618 // that the check is reached, and a series of (klassOop, count) pairs
619 // which are used to store a type profile for the receiver of the check.
620 class ReceiverTypeData : public CounterData {
621 protected:
622 enum {
623 receiver0_offset = counter_cell_count,
624 count0_offset,
625 receiver_type_row_cell_count = (count0_offset + 1) - receiver0_offset
626 };
628 public:
629 ReceiverTypeData(DataLayout* layout) : CounterData(layout) {
630 assert(layout->tag() == DataLayout::receiver_type_data_tag ||
631 layout->tag() == DataLayout::virtual_call_data_tag, "wrong type");
632 }
634 virtual bool is_ReceiverTypeData() { return true; }
636 static int static_cell_count() {
637 return counter_cell_count + (uint) TypeProfileWidth * receiver_type_row_cell_count;
638 }
640 virtual int cell_count() {
641 return static_cell_count();
642 }
644 // Direct accessors
645 static uint row_limit() {
646 return TypeProfileWidth;
647 }
648 static int receiver_cell_index(uint row) {
649 return receiver0_offset + row * receiver_type_row_cell_count;
650 }
651 static int receiver_count_cell_index(uint row) {
652 return count0_offset + row * receiver_type_row_cell_count;
653 }
655 // Get the receiver at row. The 'unchecked' version is needed by parallel old
656 // gc; it does not assert the receiver is a klass. During compaction of the
657 // perm gen, the klass may already have moved, so the is_klass() predicate
658 // would fail. The 'normal' version should be used whenever possible.
659 klassOop receiver_unchecked(uint row) {
660 assert(row < row_limit(), "oob");
661 oop recv = oop_at(receiver_cell_index(row));
662 return (klassOop)recv;
663 }
665 klassOop receiver(uint row) {
666 klassOop recv = receiver_unchecked(row);
667 assert(recv == NULL || ((oop)recv)->is_klass(), "wrong type");
668 return recv;
669 }
671 uint receiver_count(uint row) {
672 assert(row < row_limit(), "oob");
673 return uint_at(receiver_count_cell_index(row));
674 }
676 // Code generation support
677 static ByteSize receiver_offset(uint row) {
678 return cell_offset(receiver_cell_index(row));
679 }
680 static ByteSize receiver_count_offset(uint row) {
681 return cell_offset(receiver_count_cell_index(row));
682 }
683 static ByteSize receiver_type_data_size() {
684 return cell_offset(static_cell_count());
685 }
687 // GC support
688 virtual void follow_contents();
689 virtual void oop_iterate(OopClosure* blk);
690 virtual void oop_iterate_m(OopClosure* blk, MemRegion mr);
691 virtual void adjust_pointers();
693 #ifndef SERIALGC
694 // Parallel old support
695 virtual void follow_contents(ParCompactionManager* cm);
696 virtual void update_pointers();
697 virtual void update_pointers(HeapWord* beg_addr, HeapWord* end_addr);
698 #endif // SERIALGC
700 oop* adr_receiver(uint row) {
701 return adr_oop_at(receiver_cell_index(row));
702 }
704 #ifndef PRODUCT
705 void print_receiver_data_on(outputStream* st);
706 void print_data_on(outputStream* st);
707 #endif
708 };
710 // VirtualCallData
711 //
712 // A VirtualCallData is used to access profiling information about a
713 // virtual call. For now, it has nothing more than a ReceiverTypeData.
714 class VirtualCallData : public ReceiverTypeData {
715 public:
716 VirtualCallData(DataLayout* layout) : ReceiverTypeData(layout) {
717 assert(layout->tag() == DataLayout::virtual_call_data_tag, "wrong type");
718 }
720 virtual bool is_VirtualCallData() { return true; }
722 static int static_cell_count() {
723 // At this point we could add more profile state, e.g., for arguments.
724 // But for now it's the same size as the base record type.
725 return ReceiverTypeData::static_cell_count();
726 }
728 virtual int cell_count() {
729 return static_cell_count();
730 }
732 // Direct accessors
733 static ByteSize virtual_call_data_size() {
734 return cell_offset(static_cell_count());
735 }
737 #ifndef PRODUCT
738 void print_data_on(outputStream* st);
739 #endif
740 };
742 // RetData
743 //
744 // A RetData is used to access profiling information for a ret bytecode.
745 // It is composed of a count of the number of times that the ret has
746 // been executed, followed by a series of triples of the form
747 // (bci, count, di) which count the number of times that some bci was the
748 // target of the ret and cache a corresponding data displacement.
749 class RetData : public CounterData {
750 protected:
751 enum {
752 bci0_offset = counter_cell_count,
753 count0_offset,
754 displacement0_offset,
755 ret_row_cell_count = (displacement0_offset + 1) - bci0_offset
756 };
758 void set_bci(uint row, int bci) {
759 assert((uint)row < row_limit(), "oob");
760 set_int_at(bci0_offset + row * ret_row_cell_count, bci);
761 }
762 void release_set_bci(uint row, int bci) {
763 assert((uint)row < row_limit(), "oob");
764 // 'release' when setting the bci acts as a valid flag for other
765 // threads wrt bci_count and bci_displacement.
766 release_set_int_at(bci0_offset + row * ret_row_cell_count, bci);
767 }
768 void set_bci_count(uint row, uint count) {
769 assert((uint)row < row_limit(), "oob");
770 set_uint_at(count0_offset + row * ret_row_cell_count, count);
771 }
772 void set_bci_displacement(uint row, int disp) {
773 set_int_at(displacement0_offset + row * ret_row_cell_count, disp);
774 }
776 public:
777 RetData(DataLayout* layout) : CounterData(layout) {
778 assert(layout->tag() == DataLayout::ret_data_tag, "wrong type");
779 }
781 virtual bool is_RetData() { return true; }
783 enum {
784 no_bci = -1 // value of bci when bci1/2 are not in use.
785 };
787 static int static_cell_count() {
788 return counter_cell_count + (uint) BciProfileWidth * ret_row_cell_count;
789 }
791 virtual int cell_count() {
792 return static_cell_count();
793 }
795 static uint row_limit() {
796 return BciProfileWidth;
797 }
798 static int bci_cell_index(uint row) {
799 return bci0_offset + row * ret_row_cell_count;
800 }
801 static int bci_count_cell_index(uint row) {
802 return count0_offset + row * ret_row_cell_count;
803 }
804 static int bci_displacement_cell_index(uint row) {
805 return displacement0_offset + row * ret_row_cell_count;
806 }
808 // Direct accessors
809 int bci(uint row) {
810 return int_at(bci_cell_index(row));
811 }
812 uint bci_count(uint row) {
813 return uint_at(bci_count_cell_index(row));
814 }
815 int bci_displacement(uint row) {
816 return int_at(bci_displacement_cell_index(row));
817 }
819 // Interpreter Runtime support
820 address fixup_ret(int return_bci, methodDataHandle mdo);
822 // Code generation support
823 static ByteSize bci_offset(uint row) {
824 return cell_offset(bci_cell_index(row));
825 }
826 static ByteSize bci_count_offset(uint row) {
827 return cell_offset(bci_count_cell_index(row));
828 }
829 static ByteSize bci_displacement_offset(uint row) {
830 return cell_offset(bci_displacement_cell_index(row));
831 }
833 // Specific initialization.
834 void post_initialize(BytecodeStream* stream, methodDataOop mdo);
836 #ifndef PRODUCT
837 void print_data_on(outputStream* st);
838 #endif
839 };
841 // BranchData
842 //
843 // A BranchData is used to access profiling data for a two-way branch.
844 // It consists of taken and not_taken counts as well as a data displacement
845 // for the taken case.
846 class BranchData : public JumpData {
847 protected:
848 enum {
849 not_taken_off_set = jump_cell_count,
850 branch_cell_count
851 };
853 void set_displacement(int displacement) {
854 set_int_at(displacement_off_set, displacement);
855 }
857 public:
858 BranchData(DataLayout* layout) : JumpData(layout) {
859 assert(layout->tag() == DataLayout::branch_data_tag, "wrong type");
860 }
862 virtual bool is_BranchData() { return true; }
864 static int static_cell_count() {
865 return branch_cell_count;
866 }
868 virtual int cell_count() {
869 return static_cell_count();
870 }
872 // Direct accessor
873 uint not_taken() {
874 return uint_at(not_taken_off_set);
875 }
877 uint inc_not_taken() {
878 uint cnt = not_taken() + 1;
879 // Did we wrap? Will compiler screw us??
880 if (cnt == 0) cnt--;
881 set_uint_at(not_taken_off_set, cnt);
882 return cnt;
883 }
885 // Code generation support
886 static ByteSize not_taken_offset() {
887 return cell_offset(not_taken_off_set);
888 }
889 static ByteSize branch_data_size() {
890 return cell_offset(branch_cell_count);
891 }
893 // Specific initialization.
894 void post_initialize(BytecodeStream* stream, methodDataOop mdo);
896 #ifndef PRODUCT
897 void print_data_on(outputStream* st);
898 #endif
899 };
901 // ArrayData
902 //
903 // A ArrayData is a base class for accessing profiling data which does
904 // not have a statically known size. It consists of an array length
905 // and an array start.
906 class ArrayData : public ProfileData {
907 protected:
908 friend class DataLayout;
910 enum {
911 array_len_off_set,
912 array_start_off_set
913 };
915 uint array_uint_at(int index) {
916 int aindex = index + array_start_off_set;
917 return uint_at(aindex);
918 }
919 int array_int_at(int index) {
920 int aindex = index + array_start_off_set;
921 return int_at(aindex);
922 }
923 oop array_oop_at(int index) {
924 int aindex = index + array_start_off_set;
925 return oop_at(aindex);
926 }
927 void array_set_int_at(int index, int value) {
928 int aindex = index + array_start_off_set;
929 set_int_at(aindex, value);
930 }
932 // Code generation support for subclasses.
933 static ByteSize array_element_offset(int index) {
934 return cell_offset(array_start_off_set + index);
935 }
937 public:
938 ArrayData(DataLayout* layout) : ProfileData(layout) {}
940 virtual bool is_ArrayData() { return true; }
942 static int static_cell_count() {
943 return -1;
944 }
946 int array_len() {
947 return int_at_unchecked(array_len_off_set);
948 }
950 virtual int cell_count() {
951 return array_len() + 1;
952 }
954 // Code generation support
955 static ByteSize array_len_offset() {
956 return cell_offset(array_len_off_set);
957 }
958 static ByteSize array_start_offset() {
959 return cell_offset(array_start_off_set);
960 }
961 };
963 // MultiBranchData
964 //
965 // A MultiBranchData is used to access profiling information for
966 // a multi-way branch (*switch bytecodes). It consists of a series
967 // of (count, displacement) pairs, which count the number of times each
968 // case was taken and specify the data displacment for each branch target.
969 class MultiBranchData : public ArrayData {
970 protected:
971 enum {
972 default_count_off_set,
973 default_disaplacement_off_set,
974 case_array_start
975 };
976 enum {
977 relative_count_off_set,
978 relative_displacement_off_set,
979 per_case_cell_count
980 };
982 void set_default_displacement(int displacement) {
983 array_set_int_at(default_disaplacement_off_set, displacement);
984 }
985 void set_displacement_at(int index, int displacement) {
986 array_set_int_at(case_array_start +
987 index * per_case_cell_count +
988 relative_displacement_off_set,
989 displacement);
990 }
992 public:
993 MultiBranchData(DataLayout* layout) : ArrayData(layout) {
994 assert(layout->tag() == DataLayout::multi_branch_data_tag, "wrong type");
995 }
997 virtual bool is_MultiBranchData() { return true; }
999 static int compute_cell_count(BytecodeStream* stream);
1001 int number_of_cases() {
1002 int alen = array_len() - 2; // get rid of default case here.
1003 assert(alen % per_case_cell_count == 0, "must be even");
1004 return (alen / per_case_cell_count);
1005 }
1007 uint default_count() {
1008 return array_uint_at(default_count_off_set);
1009 }
1010 int default_displacement() {
1011 return array_int_at(default_disaplacement_off_set);
1012 }
1014 uint count_at(int index) {
1015 return array_uint_at(case_array_start +
1016 index * per_case_cell_count +
1017 relative_count_off_set);
1018 }
1019 int displacement_at(int index) {
1020 return array_int_at(case_array_start +
1021 index * per_case_cell_count +
1022 relative_displacement_off_set);
1023 }
1025 // Code generation support
1026 static ByteSize default_count_offset() {
1027 return array_element_offset(default_count_off_set);
1028 }
1029 static ByteSize default_displacement_offset() {
1030 return array_element_offset(default_disaplacement_off_set);
1031 }
1032 static ByteSize case_count_offset(int index) {
1033 return case_array_offset() +
1034 (per_case_size() * index) +
1035 relative_count_offset();
1036 }
1037 static ByteSize case_array_offset() {
1038 return array_element_offset(case_array_start);
1039 }
1040 static ByteSize per_case_size() {
1041 return in_ByteSize(per_case_cell_count) * cell_size;
1042 }
1043 static ByteSize relative_count_offset() {
1044 return in_ByteSize(relative_count_off_set) * cell_size;
1045 }
1046 static ByteSize relative_displacement_offset() {
1047 return in_ByteSize(relative_displacement_off_set) * cell_size;
1048 }
1050 // Specific initialization.
1051 void post_initialize(BytecodeStream* stream, methodDataOop mdo);
1053 #ifndef PRODUCT
1054 void print_data_on(outputStream* st);
1055 #endif
1056 };
1058 class ArgInfoData : public ArrayData {
1060 public:
1061 ArgInfoData(DataLayout* layout) : ArrayData(layout) {
1062 assert(layout->tag() == DataLayout::arg_info_data_tag, "wrong type");
1063 }
1065 virtual bool is_ArgInfoData() { return true; }
1068 int number_of_args() {
1069 return array_len();
1070 }
1072 uint arg_modified(int arg) {
1073 return array_uint_at(arg);
1074 }
1076 void set_arg_modified(int arg, uint val) {
1077 array_set_int_at(arg, val);
1078 }
1080 #ifndef PRODUCT
1081 void print_data_on(outputStream* st);
1082 #endif
1083 };
1085 // methodDataOop
1086 //
1087 // A methodDataOop holds information which has been collected about
1088 // a method. Its layout looks like this:
1089 //
1090 // -----------------------------
1091 // | header |
1092 // | klass |
1093 // -----------------------------
1094 // | method |
1095 // | size of the methodDataOop |
1096 // -----------------------------
1097 // | Data entries... |
1098 // | (variable size) |
1099 // | |
1100 // . .
1101 // . .
1102 // . .
1103 // | |
1104 // -----------------------------
1105 //
1106 // The data entry area is a heterogeneous array of DataLayouts. Each
1107 // DataLayout in the array corresponds to a specific bytecode in the
1108 // method. The entries in the array are sorted by the corresponding
1109 // bytecode. Access to the data is via resource-allocated ProfileData,
1110 // which point to the underlying blocks of DataLayout structures.
1111 //
1112 // During interpretation, if profiling in enabled, the interpreter
1113 // maintains a method data pointer (mdp), which points at the entry
1114 // in the array corresponding to the current bci. In the course of
1115 // intepretation, when a bytecode is encountered that has profile data
1116 // associated with it, the entry pointed to by mdp is updated, then the
1117 // mdp is adjusted to point to the next appropriate DataLayout. If mdp
1118 // is NULL to begin with, the interpreter assumes that the current method
1119 // is not (yet) being profiled.
1120 //
1121 // In methodDataOop parlance, "dp" is a "data pointer", the actual address
1122 // of a DataLayout element. A "di" is a "data index", the offset in bytes
1123 // from the base of the data entry array. A "displacement" is the byte offset
1124 // in certain ProfileData objects that indicate the amount the mdp must be
1125 // adjusted in the event of a change in control flow.
1126 //
1128 class methodDataOopDesc : public oopDesc {
1129 friend class VMStructs;
1130 private:
1131 friend class ProfileData;
1133 // Back pointer to the methodOop
1134 methodOop _method;
1136 // Size of this oop in bytes
1137 int _size;
1139 // Cached hint for bci_to_dp and bci_to_data
1140 int _hint_di;
1142 // Whole-method sticky bits and flags
1143 public:
1144 enum {
1145 _trap_hist_limit = 16, // decoupled from Deoptimization::Reason_LIMIT
1146 _trap_hist_mask = max_jubyte,
1147 _extra_data_count = 4 // extra DataLayout headers, for trap history
1148 }; // Public flag values
1149 private:
1150 uint _nof_decompiles; // count of all nmethod removals
1151 uint _nof_overflow_recompiles; // recompile count, excluding recomp. bits
1152 uint _nof_overflow_traps; // trap count, excluding _trap_hist
1153 union {
1154 intptr_t _align;
1155 u1 _array[_trap_hist_limit];
1156 } _trap_hist;
1158 // Support for interprocedural escape analysis, from Thomas Kotzmann.
1159 intx _eflags; // flags on escape information
1160 intx _arg_local; // bit set of non-escaping arguments
1161 intx _arg_stack; // bit set of stack-allocatable arguments
1162 intx _arg_returned; // bit set of returned arguments
1164 int _creation_mileage; // method mileage at MDO creation
1166 // Size of _data array in bytes. (Excludes header and extra_data fields.)
1167 int _data_size;
1169 // Beginning of the data entries
1170 intptr_t _data[1];
1172 // Helper for size computation
1173 static int compute_data_size(BytecodeStream* stream);
1174 static int bytecode_cell_count(Bytecodes::Code code);
1175 enum { no_profile_data = -1, variable_cell_count = -2 };
1177 // Helper for initialization
1178 DataLayout* data_layout_at(int data_index) {
1179 assert(data_index % sizeof(intptr_t) == 0, "unaligned");
1180 return (DataLayout*) (((address)_data) + data_index);
1181 }
1183 // Initialize an individual data segment. Returns the size of
1184 // the segment in bytes.
1185 int initialize_data(BytecodeStream* stream, int data_index);
1187 // Helper for data_at
1188 DataLayout* limit_data_position() {
1189 return (DataLayout*)((address)data_base() + _data_size);
1190 }
1191 bool out_of_bounds(int data_index) {
1192 return data_index >= data_size();
1193 }
1195 // Give each of the data entries a chance to perform specific
1196 // data initialization.
1197 void post_initialize(BytecodeStream* stream);
1199 // hint accessors
1200 int hint_di() const { return _hint_di; }
1201 void set_hint_di(int di) {
1202 assert(!out_of_bounds(di), "hint_di out of bounds");
1203 _hint_di = di;
1204 }
1205 ProfileData* data_before(int bci) {
1206 // avoid SEGV on this edge case
1207 if (data_size() == 0)
1208 return NULL;
1209 int hint = hint_di();
1210 if (data_layout_at(hint)->bci() <= bci)
1211 return data_at(hint);
1212 return first_data();
1213 }
1215 // What is the index of the first data entry?
1216 int first_di() { return 0; }
1218 // Find or create an extra ProfileData:
1219 ProfileData* bci_to_extra_data(int bci, bool create_if_missing);
1221 // return the argument info cell
1222 ArgInfoData *arg_info();
1224 public:
1225 static int header_size() {
1226 return sizeof(methodDataOopDesc)/wordSize;
1227 }
1229 // Compute the size of a methodDataOop before it is created.
1230 static int compute_allocation_size_in_bytes(methodHandle method);
1231 static int compute_allocation_size_in_words(methodHandle method);
1232 static int compute_extra_data_count(int data_size, int empty_bc_count);
1234 // Determine if a given bytecode can have profile information.
1235 static bool bytecode_has_profile(Bytecodes::Code code) {
1236 return bytecode_cell_count(code) != no_profile_data;
1237 }
1239 // Perform initialization of a new methodDataOop
1240 void initialize(methodHandle method);
1242 // My size
1243 int object_size_in_bytes() { return _size; }
1244 int object_size() {
1245 return align_object_size(align_size_up(_size, BytesPerWord)/BytesPerWord);
1246 }
1248 int creation_mileage() const { return _creation_mileage; }
1249 void set_creation_mileage(int x) { _creation_mileage = x; }
1250 bool is_mature() const; // consult mileage and ProfileMaturityPercentage
1251 static int mileage_of(methodOop m);
1253 // Support for interprocedural escape analysis, from Thomas Kotzmann.
1254 enum EscapeFlag {
1255 estimated = 1 << 0,
1256 return_local = 1 << 1,
1257 return_allocated = 1 << 2,
1258 allocated_escapes = 1 << 3,
1259 unknown_modified = 1 << 4
1260 };
1262 intx eflags() { return _eflags; }
1263 intx arg_local() { return _arg_local; }
1264 intx arg_stack() { return _arg_stack; }
1265 intx arg_returned() { return _arg_returned; }
1266 uint arg_modified(int a) { ArgInfoData *aid = arg_info();
1267 assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
1268 return aid->arg_modified(a); }
1270 void set_eflags(intx v) { _eflags = v; }
1271 void set_arg_local(intx v) { _arg_local = v; }
1272 void set_arg_stack(intx v) { _arg_stack = v; }
1273 void set_arg_returned(intx v) { _arg_returned = v; }
1274 void set_arg_modified(int a, uint v) { ArgInfoData *aid = arg_info();
1275 assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
1277 aid->set_arg_modified(a, v); }
1279 void clear_escape_info() { _eflags = _arg_local = _arg_stack = _arg_returned = 0; }
1281 // Location and size of data area
1282 address data_base() const {
1283 return (address) _data;
1284 }
1285 int data_size() {
1286 return _data_size;
1287 }
1289 // Accessors
1290 methodOop method() { return _method; }
1292 // Get the data at an arbitrary (sort of) data index.
1293 ProfileData* data_at(int data_index);
1295 // Walk through the data in order.
1296 ProfileData* first_data() { return data_at(first_di()); }
1297 ProfileData* next_data(ProfileData* current);
1298 bool is_valid(ProfileData* current) { return current != NULL; }
1300 // Convert a dp (data pointer) to a di (data index).
1301 int dp_to_di(address dp) {
1302 return dp - ((address)_data);
1303 }
1305 address di_to_dp(int di) {
1306 return (address)data_layout_at(di);
1307 }
1309 // bci to di/dp conversion.
1310 address bci_to_dp(int bci);
1311 int bci_to_di(int bci) {
1312 return dp_to_di(bci_to_dp(bci));
1313 }
1315 // Get the data at an arbitrary bci, or NULL if there is none.
1316 ProfileData* bci_to_data(int bci);
1318 // Same, but try to create an extra_data record if one is needed:
1319 ProfileData* allocate_bci_to_data(int bci) {
1320 ProfileData* data = bci_to_data(bci);
1321 return (data != NULL) ? data : bci_to_extra_data(bci, true);
1322 }
1324 // Add a handful of extra data records, for trap tracking.
1325 DataLayout* extra_data_base() { return limit_data_position(); }
1326 DataLayout* extra_data_limit() { return (DataLayout*)((address)this + object_size_in_bytes()); }
1327 int extra_data_size() { return (address)extra_data_limit()
1328 - (address)extra_data_base(); }
1329 static DataLayout* next_extra(DataLayout* dp) { return (DataLayout*)((address)dp + in_bytes(DataLayout::cell_offset(0))); }
1331 // Return (uint)-1 for overflow.
1332 uint trap_count(int reason) const {
1333 assert((uint)reason < _trap_hist_limit, "oob");
1334 return (int)((_trap_hist._array[reason]+1) & _trap_hist_mask) - 1;
1335 }
1336 // For loops:
1337 static uint trap_reason_limit() { return _trap_hist_limit; }
1338 static uint trap_count_limit() { return _trap_hist_mask; }
1339 uint inc_trap_count(int reason) {
1340 // Count another trap, anywhere in this method.
1341 assert(reason >= 0, "must be single trap");
1342 if ((uint)reason < _trap_hist_limit) {
1343 uint cnt1 = 1 + _trap_hist._array[reason];
1344 if ((cnt1 & _trap_hist_mask) != 0) { // if no counter overflow...
1345 _trap_hist._array[reason] = cnt1;
1346 return cnt1;
1347 } else {
1348 return _trap_hist_mask + (++_nof_overflow_traps);
1349 }
1350 } else {
1351 // Could not represent the count in the histogram.
1352 return (++_nof_overflow_traps);
1353 }
1354 }
1356 uint overflow_trap_count() const {
1357 return _nof_overflow_traps;
1358 }
1359 uint overflow_recompile_count() const {
1360 return _nof_overflow_recompiles;
1361 }
1362 void inc_overflow_recompile_count() {
1363 _nof_overflow_recompiles += 1;
1364 }
1365 uint decompile_count() const {
1366 return _nof_decompiles;
1367 }
1368 void inc_decompile_count() {
1369 _nof_decompiles += 1;
1370 }
1372 // Support for code generation
1373 static ByteSize data_offset() {
1374 return byte_offset_of(methodDataOopDesc, _data[0]);
1375 }
1377 // GC support
1378 oop* adr_method() const { return (oop*)&_method; }
1379 bool object_is_parsable() const { return _size != 0; }
1380 void set_object_is_parsable(int object_size_in_bytes) { _size = object_size_in_bytes; }
1382 #ifndef PRODUCT
1383 // printing support for method data
1384 void print_data_on(outputStream* st);
1385 #endif
1387 // verification
1388 void verify_data_on(outputStream* st);
1389 };