1 /*
2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "jvm.h"
27 #include "interpreter/bytecodeStream.hpp"
28 #include "logging/log.hpp"
29 #include "logging/logStream.hpp"
30 #include "memory/allocation.inline.hpp"
31 #include "oops/generateOopMap.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "oops/symbol.hpp"
34 #include "runtime/handles.inline.hpp"
35 #include "runtime/java.hpp"
36 #include "runtime/relocator.hpp"
37 #include "runtime/timerTrace.hpp"
38 #include "utilities/bitMap.inline.hpp"
39 #include "utilities/ostream.hpp"
40
41 //
42 //
43 // Compute stack layouts for each instruction in method.
44 //
45 // Problems:
46 // - What to do about jsr with different types of local vars?
47 // Need maps that are conditional on jsr path?
48 // - Jsr and exceptions should be done more efficiently (the retAddr stuff)
49 //
50 // Alternative:
51 // - Could extend verifier to provide this information.
52 // For: one fewer abstract interpreter to maintain. Against: the verifier
53 // solves a bigger problem so slower (undesirable to force verification of
54 // everything?).
55 //
56 // Algorithm:
57 // Partition bytecodes into basic blocks
58 // For each basic block: store entry state (vars, stack). For instructions
59 // inside basic blocks we do not store any state (instead we recompute it
60 // from state produced by previous instruction).
61 //
62 // Perform abstract interpretation of bytecodes over this lattice:
63 //
64 // _--'#'--_
65 // / / \ \
66 // / / \ \
67 // / | | \
68 // 'r' 'v' 'p' ' '
69 // \ | | /
70 // \ \ / /
71 // \ \ / /
72 // -- '@' --
73 //
74 // '#' top, result of conflict merge
75 // 'r' reference type
76 // 'v' value type
77 // 'p' pc type for jsr/ret
78 // ' ' uninitialized; never occurs on operand stack in Java
79 // '@' bottom/unexecuted; initial state each bytecode.
80 //
81 // Basic block headers are the only merge points. We use this iteration to
82 // compute the information:
83 //
84 // find basic blocks;
85 // initialize them with uninitialized state;
86 // initialize first BB according to method signature;
87 // mark first BB changed
88 // while (some BB is changed) do {
89 // perform abstract interpration of all bytecodes in BB;
90 // merge exit state of BB into entry state of all successor BBs,
91 // noting if any of these change;
92 // }
93 //
94 // One additional complication is necessary. The jsr instruction pushes
95 // a return PC on the stack (a 'p' type in the abstract interpretation).
96 // To be able to process "ret" bytecodes, we keep track of these return
97 // PC's in a 'retAddrs' structure in abstract interpreter context (when
98 // processing a "ret" bytecodes, it is not sufficient to know that it gets
99 // an argument of the right type 'p'; we need to know which address it
100 // returns to).
101 //
102 // (Note this comment is borrowed form the original author of the algorithm)
103
104 // ComputeCallStack
105 //
106 // Specialization of SignatureIterator - compute the effects of a call
107 //
108 class ComputeCallStack : public SignatureIterator {
109 CellTypeState *_effect;
110 int _idx;
111
112 void setup();
113 void set(CellTypeState state) { _effect[_idx++] = state; }
114 int length() { return _idx; };
115
116 virtual void do_bool () { set(CellTypeState::value); };
117 virtual void do_char () { set(CellTypeState::value); };
118 virtual void do_float () { set(CellTypeState::value); };
119 virtual void do_byte () { set(CellTypeState::value); };
120 virtual void do_short () { set(CellTypeState::value); };
121 virtual void do_int () { set(CellTypeState::value); };
122 virtual void do_void () { set(CellTypeState::bottom);};
123 virtual void do_object(int begin, int end) { set(CellTypeState::ref); };
124 virtual void do_array (int begin, int end) { set(CellTypeState::ref); };
125
126 void do_double() { set(CellTypeState::value);
127 set(CellTypeState::value); }
128 void do_long () { set(CellTypeState::value);
129 set(CellTypeState::value); }
130
131 public:
132 ComputeCallStack(Symbol* signature) : SignatureIterator(signature) {};
133
134 // Compute methods
135 int compute_for_parameters(bool is_static, CellTypeState *effect) {
136 _idx = 0;
137 _effect = effect;
138
139 if (!is_static) {
140 effect[_idx++] = CellTypeState::ref;
141 }
142
143 iterate_parameters();
144
145 return length();
146 };
147
148 int compute_for_returntype(CellTypeState *effect) {
149 _idx = 0;
150 _effect = effect;
151 iterate_returntype();
152 set(CellTypeState::bottom); // Always terminate with a bottom state, so ppush works
153
154 return length();
155 }
156 };
157
158 //=========================================================================================
159 // ComputeEntryStack
160 //
161 // Specialization of SignatureIterator - in order to set up first stack frame
162 //
163 class ComputeEntryStack : public SignatureIterator {
164 CellTypeState *_effect;
165 int _idx;
166
167 void setup();
168 void set(CellTypeState state) { _effect[_idx++] = state; }
169 int length() { return _idx; };
170
171 virtual void do_bool () { set(CellTypeState::value); };
172 virtual void do_char () { set(CellTypeState::value); };
173 virtual void do_float () { set(CellTypeState::value); };
174 virtual void do_byte () { set(CellTypeState::value); };
175 virtual void do_short () { set(CellTypeState::value); };
176 virtual void do_int () { set(CellTypeState::value); };
177 virtual void do_void () { set(CellTypeState::bottom);};
178 virtual void do_object(int begin, int end) { set(CellTypeState::make_slot_ref(_idx)); }
179 virtual void do_array (int begin, int end) { set(CellTypeState::make_slot_ref(_idx)); }
180
181 void do_double() { set(CellTypeState::value);
182 set(CellTypeState::value); }
183 void do_long () { set(CellTypeState::value);
184 set(CellTypeState::value); }
185
186 public:
187 ComputeEntryStack(Symbol* signature) : SignatureIterator(signature) {};
188
189 // Compute methods
190 int compute_for_parameters(bool is_static, CellTypeState *effect) {
191 _idx = 0;
192 _effect = effect;
193
194 if (!is_static)
195 effect[_idx++] = CellTypeState::make_slot_ref(0);
196
197 iterate_parameters();
198
199 return length();
200 };
201
202 int compute_for_returntype(CellTypeState *effect) {
203 _idx = 0;
204 _effect = effect;
205 iterate_returntype();
206 set(CellTypeState::bottom); // Always terminate with a bottom state, so ppush works
207
208 return length();
209 }
210 };
211
212 //=====================================================================================
213 //
214 // Implementation of RetTable/RetTableEntry
215 //
216 // Contains function to itereate through all bytecodes
217 // and find all return entry points
218 //
219 int RetTable::_init_nof_entries = 10;
220 int RetTableEntry::_init_nof_jsrs = 5;
221
222 RetTableEntry::RetTableEntry(int target, RetTableEntry *next) {
223 _target_bci = target;
224 _jsrs = new GrowableArray<intptr_t>(_init_nof_jsrs);
225 _next = next;
226 }
227
228 void RetTableEntry::add_delta(int bci, int delta) {
229 if (_target_bci > bci) _target_bci += delta;
230
231 for (int k = 0; k < _jsrs->length(); k++) {
232 int jsr = _jsrs->at(k);
233 if (jsr > bci) _jsrs->at_put(k, jsr+delta);
234 }
235 }
236
237 void RetTable::compute_ret_table(const methodHandle& method) {
238 BytecodeStream i(method);
239 Bytecodes::Code bytecode;
240
241 while( (bytecode = i.next()) >= 0) {
242 switch (bytecode) {
243 case Bytecodes::_jsr:
244 add_jsr(i.next_bci(), i.dest());
245 break;
246 case Bytecodes::_jsr_w:
247 add_jsr(i.next_bci(), i.dest_w());
248 break;
249 default:
250 break;
251 }
252 }
253 }
254
255 void RetTable::add_jsr(int return_bci, int target_bci) {
256 RetTableEntry* entry = _first;
257
258 // Scan table for entry
259 for (;entry && entry->target_bci() != target_bci; entry = entry->next());
260
261 if (!entry) {
262 // Allocate new entry and put in list
263 entry = new RetTableEntry(target_bci, _first);
264 _first = entry;
265 }
266
267 // Now "entry" is set. Make sure that the entry is initialized
268 // and has room for the new jsr.
269 entry->add_jsr(return_bci);
270 }
271
272 RetTableEntry* RetTable::find_jsrs_for_target(int targBci) {
273 RetTableEntry *cur = _first;
274
275 while(cur) {
276 assert(cur->target_bci() != -1, "sanity check");
277 if (cur->target_bci() == targBci) return cur;
278 cur = cur->next();
279 }
280 ShouldNotReachHere();
281 return NULL;
282 }
283
284 // The instruction at bci is changing size by "delta". Update the return map.
285 void RetTable::update_ret_table(int bci, int delta) {
286 RetTableEntry *cur = _first;
287 while(cur) {
288 cur->add_delta(bci, delta);
289 cur = cur->next();
290 }
291 }
292
293 //
294 // Celltype state
295 //
296
297 CellTypeState CellTypeState::bottom = CellTypeState::make_bottom();
298 CellTypeState CellTypeState::uninit = CellTypeState::make_any(uninit_value);
299 CellTypeState CellTypeState::ref = CellTypeState::make_any(ref_conflict);
300 CellTypeState CellTypeState::value = CellTypeState::make_any(val_value);
301 CellTypeState CellTypeState::refUninit = CellTypeState::make_any(ref_conflict | uninit_value);
302 CellTypeState CellTypeState::top = CellTypeState::make_top();
303 CellTypeState CellTypeState::addr = CellTypeState::make_any(addr_conflict);
304
305 // Commonly used constants
306 static CellTypeState epsilonCTS[1] = { CellTypeState::bottom };
307 static CellTypeState refCTS = CellTypeState::ref;
308 static CellTypeState valCTS = CellTypeState::value;
309 static CellTypeState vCTS[2] = { CellTypeState::value, CellTypeState::bottom };
310 static CellTypeState rCTS[2] = { CellTypeState::ref, CellTypeState::bottom };
311 static CellTypeState rrCTS[3] = { CellTypeState::ref, CellTypeState::ref, CellTypeState::bottom };
312 static CellTypeState vrCTS[3] = { CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
313 static CellTypeState vvCTS[3] = { CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
314 static CellTypeState rvrCTS[4] = { CellTypeState::ref, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
315 static CellTypeState vvrCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
316 static CellTypeState vvvCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
317 static CellTypeState vvvrCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
318 static CellTypeState vvvvCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
319
320 char CellTypeState::to_char() const {
321 if (can_be_reference()) {
322 if (can_be_value() || can_be_address())
323 return '#'; // Conflict that needs to be rewritten
324 else
325 return 'r';
326 } else if (can_be_value())
327 return 'v';
328 else if (can_be_address())
329 return 'p';
330 else if (can_be_uninit())
331 return ' ';
332 else
333 return '@';
334 }
335
336
337 // Print a detailed CellTypeState. Indicate all bits that are set. If
338 // the CellTypeState represents an address or a reference, print the
339 // value of the additional information.
340 void CellTypeState::print(outputStream *os) {
341 if (can_be_address()) {
342 os->print("(p");
343 } else {
344 os->print("( ");
345 }
346 if (can_be_reference()) {
347 os->print("r");
348 } else {
349 os->print(" ");
350 }
351 if (can_be_value()) {
352 os->print("v");
353 } else {
354 os->print(" ");
355 }
356 if (can_be_uninit()) {
357 os->print("u|");
358 } else {
359 os->print(" |");
360 }
361 if (is_info_top()) {
362 os->print("Top)");
363 } else if (is_info_bottom()) {
364 os->print("Bot)");
365 } else {
366 if (is_reference()) {
367 int info = get_info();
368 int data = info & ~(ref_not_lock_bit | ref_slot_bit);
369 if (info & ref_not_lock_bit) {
370 // Not a monitor lock reference.
371 if (info & ref_slot_bit) {
372 // slot
373 os->print("slot%d)", data);
374 } else {
375 // line
376 os->print("line%d)", data);
377 }
378 } else {
379 // lock
380 os->print("lock%d)", data);
381 }
382 } else {
383 os->print("%d)", get_info());
384 }
385 }
386 }
387
388 //
389 // Basicblock handling methods
390 //
391
392 void GenerateOopMap::initialize_bb() {
393 _gc_points = 0;
394 _bb_count = 0;
395 _bb_hdr_bits.reinitialize(method()->code_size());
396 }
397
398 void GenerateOopMap::bb_mark_fct(GenerateOopMap *c, int bci, int *data) {
399 assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
400 if (c->is_bb_header(bci))
401 return;
402
403 if (TraceNewOopMapGeneration) {
404 tty->print_cr("Basicblock#%d begins at: %d", c->_bb_count, bci);
405 }
406 c->set_bbmark_bit(bci);
407 c->_bb_count++;
408 }
409
410
411 void GenerateOopMap::mark_bbheaders_and_count_gc_points() {
412 initialize_bb();
413
414 bool fellThrough = false; // False to get first BB marked.
415
416 // First mark all exception handlers as start of a basic-block
417 ExceptionTable excps(method());
418 for(int i = 0; i < excps.length(); i ++) {
419 bb_mark_fct(this, excps.handler_pc(i), NULL);
420 }
421
422 // Then iterate through the code
423 BytecodeStream bcs(_method);
424 Bytecodes::Code bytecode;
425
426 while( (bytecode = bcs.next()) >= 0) {
427 int bci = bcs.bci();
428
429 if (!fellThrough)
430 bb_mark_fct(this, bci, NULL);
431
432 fellThrough = jump_targets_do(&bcs, &GenerateOopMap::bb_mark_fct, NULL);
433
434 /* We will also mark successors of jsr's as basic block headers. */
435 switch (bytecode) {
436 case Bytecodes::_jsr:
437 assert(!fellThrough, "should not happen");
438 bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), NULL);
439 break;
440 case Bytecodes::_jsr_w:
441 assert(!fellThrough, "should not happen");
442 bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), NULL);
443 break;
444 default:
445 break;
446 }
447
448 if (possible_gc_point(&bcs))
449 _gc_points++;
450 }
451 }
452
453 void GenerateOopMap::set_bbmark_bit(int bci) {
454 _bb_hdr_bits.at_put(bci, true);
455 }
456
457 void GenerateOopMap::reachable_basicblock(GenerateOopMap *c, int bci, int *data) {
458 assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
459 BasicBlock* bb = c->get_basic_block_at(bci);
460 if (bb->is_dead()) {
461 bb->mark_as_alive();
462 *data = 1; // Mark basicblock as changed
463 }
464 }
465
466
467 void GenerateOopMap::mark_reachable_code() {
468 int change = 1; // int to get function pointers to work
469
470 // Mark entry basic block as alive and all exception handlers
471 _basic_blocks[0].mark_as_alive();
472 ExceptionTable excps(method());
473 for(int i = 0; i < excps.length(); i++) {
474 BasicBlock *bb = get_basic_block_at(excps.handler_pc(i));
475 // If block is not already alive (due to multiple exception handlers to same bb), then
476 // make it alive
477 if (bb->is_dead()) bb->mark_as_alive();
478 }
479
480 BytecodeStream bcs(_method);
481
482 // Iterate through all basic blocks until we reach a fixpoint
483 while (change) {
484 change = 0;
485
486 for (int i = 0; i < _bb_count; i++) {
487 BasicBlock *bb = &_basic_blocks[i];
488 if (bb->is_alive()) {
489 // Position bytecodestream at last bytecode in basicblock
490 bcs.set_start(bb->_end_bci);
491 bcs.next();
492 Bytecodes::Code bytecode = bcs.code();
493 int bci = bcs.bci();
494 assert(bci == bb->_end_bci, "wrong bci");
495
496 bool fell_through = jump_targets_do(&bcs, &GenerateOopMap::reachable_basicblock, &change);
497
498 // We will also mark successors of jsr's as alive.
499 switch (bytecode) {
500 case Bytecodes::_jsr:
501 case Bytecodes::_jsr_w:
502 assert(!fell_through, "should not happen");
503 reachable_basicblock(this, bci + Bytecodes::length_for(bytecode), &change);
504 break;
505 default:
506 break;
507 }
508 if (fell_through) {
509 // Mark successor as alive
510 if (bb[1].is_dead()) {
511 bb[1].mark_as_alive();
512 change = 1;
513 }
514 }
515 }
516 }
517 }
518 }
519
520 /* If the current instruction in "c" has no effect on control flow,
521 returns "true". Otherwise, calls "jmpFct" one or more times, with
522 "c", an appropriate "pcDelta", and "data" as arguments, then
523 returns "false". There is one exception: if the current
524 instruction is a "ret", returns "false" without calling "jmpFct".
525 Arrangements for tracking the control flow of a "ret" must be made
526 externally. */
527 bool GenerateOopMap::jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int *data) {
528 int bci = bcs->bci();
529
530 switch (bcs->code()) {
531 case Bytecodes::_ifeq:
532 case Bytecodes::_ifne:
533 case Bytecodes::_iflt:
534 case Bytecodes::_ifge:
535 case Bytecodes::_ifgt:
536 case Bytecodes::_ifle:
537 case Bytecodes::_if_icmpeq:
538 case Bytecodes::_if_icmpne:
539 case Bytecodes::_if_icmplt:
540 case Bytecodes::_if_icmpge:
541 case Bytecodes::_if_icmpgt:
542 case Bytecodes::_if_icmple:
543 case Bytecodes::_if_acmpeq:
544 case Bytecodes::_if_acmpne:
545 case Bytecodes::_ifnull:
546 case Bytecodes::_ifnonnull:
547 (*jmpFct)(this, bcs->dest(), data);
548 (*jmpFct)(this, bci + 3, data);
549 break;
550
551 case Bytecodes::_goto:
552 (*jmpFct)(this, bcs->dest(), data);
553 break;
554 case Bytecodes::_goto_w:
555 (*jmpFct)(this, bcs->dest_w(), data);
556 break;
557 case Bytecodes::_tableswitch:
558 { Bytecode_tableswitch tableswitch(method(), bcs->bcp());
559 int len = tableswitch.length();
560
561 (*jmpFct)(this, bci + tableswitch.default_offset(), data); /* Default. jump address */
562 while (--len >= 0) {
563 (*jmpFct)(this, bci + tableswitch.dest_offset_at(len), data);
564 }
565 break;
566 }
567
568 case Bytecodes::_lookupswitch:
569 { Bytecode_lookupswitch lookupswitch(method(), bcs->bcp());
570 int npairs = lookupswitch.number_of_pairs();
571 (*jmpFct)(this, bci + lookupswitch.default_offset(), data); /* Default. */
572 while(--npairs >= 0) {
573 LookupswitchPair pair = lookupswitch.pair_at(npairs);
574 (*jmpFct)(this, bci + pair.offset(), data);
575 }
576 break;
577 }
578 case Bytecodes::_jsr:
579 assert(bcs->is_wide()==false, "sanity check");
580 (*jmpFct)(this, bcs->dest(), data);
581
582
583
584 break;
585 case Bytecodes::_jsr_w:
586 (*jmpFct)(this, bcs->dest_w(), data);
587 break;
588 case Bytecodes::_wide:
589 ShouldNotReachHere();
590 return true;
591 break;
592 case Bytecodes::_athrow:
593 case Bytecodes::_ireturn:
594 case Bytecodes::_lreturn:
595 case Bytecodes::_freturn:
596 case Bytecodes::_dreturn:
597 case Bytecodes::_areturn:
598 case Bytecodes::_return:
599 case Bytecodes::_ret:
600 break;
601 default:
602 return true;
603 }
604 return false;
605 }
606
607 /* Requires "pc" to be the head of a basic block; returns that basic
608 block. */
609 BasicBlock *GenerateOopMap::get_basic_block_at(int bci) const {
610 BasicBlock* bb = get_basic_block_containing(bci);
611 assert(bb->_bci == bci, "should have found BB");
612 return bb;
613 }
614
615 // Requires "pc" to be the start of an instruction; returns the basic
616 // block containing that instruction. */
617 BasicBlock *GenerateOopMap::get_basic_block_containing(int bci) const {
618 BasicBlock *bbs = _basic_blocks;
619 int lo = 0, hi = _bb_count - 1;
620
621 while (lo <= hi) {
622 int m = (lo + hi) / 2;
623 int mbci = bbs[m]._bci;
624 int nbci;
625
626 if ( m == _bb_count-1) {
627 assert( bci >= mbci && bci < method()->code_size(), "sanity check failed");
628 return bbs+m;
629 } else {
630 nbci = bbs[m+1]._bci;
631 }
632
633 if ( mbci <= bci && bci < nbci) {
634 return bbs+m;
635 } else if (mbci < bci) {
636 lo = m + 1;
637 } else {
638 assert(mbci > bci, "sanity check");
639 hi = m - 1;
640 }
641 }
642
643 fatal("should have found BB");
644 return NULL;
645 }
646
647 void GenerateOopMap::restore_state(BasicBlock *bb)
648 {
649 memcpy(_state, bb->_state, _state_len*sizeof(CellTypeState));
650 _stack_top = bb->_stack_top;
651 _monitor_top = bb->_monitor_top;
652 }
653
654 int GenerateOopMap::next_bb_start_pc(BasicBlock *bb) {
655 int bbNum = bb - _basic_blocks + 1;
656 if (bbNum == _bb_count)
657 return method()->code_size();
658
659 return _basic_blocks[bbNum]._bci;
660 }
661
662 //
663 // CellType handling methods
664 //
665
666 // Allocate memory and throw LinkageError if failure.
667 #define ALLOC_RESOURCE_ARRAY(var, type, count) \
668 var = NEW_RESOURCE_ARRAY_RETURN_NULL(type, count); \
669 if (var == NULL) { \
670 report_error("Cannot reserve enough memory to analyze this method"); \
671 return; \
672 }
673
674
675 void GenerateOopMap::init_state() {
676 _state_len = _max_locals + _max_stack + _max_monitors;
677 ALLOC_RESOURCE_ARRAY(_state, CellTypeState, _state_len);
678 memset(_state, 0, _state_len * sizeof(CellTypeState));
679 int count = MAX3(_max_locals, _max_stack, _max_monitors) + 1/*for null terminator char */;
680 ALLOC_RESOURCE_ARRAY(_state_vec_buf, char, count);
681 }
682
683 void GenerateOopMap::make_context_uninitialized() {
684 CellTypeState* vs = vars();
685
686 for (int i = 0; i < _max_locals; i++)
687 vs[i] = CellTypeState::uninit;
688
689 _stack_top = 0;
690 _monitor_top = 0;
691 }
692
693 int GenerateOopMap::methodsig_to_effect(Symbol* signature, bool is_static, CellTypeState* effect) {
694 ComputeEntryStack ces(signature);
695 return ces.compute_for_parameters(is_static, effect);
696 }
697
698 // Return result of merging cts1 and cts2.
699 CellTypeState CellTypeState::merge(CellTypeState cts, int slot) const {
700 CellTypeState result;
701
702 assert(!is_bottom() && !cts.is_bottom(),
703 "merge of bottom values is handled elsewhere");
704
705 result._state = _state | cts._state;
706
707 // If the top bit is set, we don't need to do any more work.
708 if (!result.is_info_top()) {
709 assert((result.can_be_address() || result.can_be_reference()),
710 "only addresses and references have non-top info");
711
712 if (!equal(cts)) {
713 // The two values being merged are different. Raise to top.
714 if (result.is_reference()) {
715 result = CellTypeState::make_slot_ref(slot);
716 } else {
717 result._state |= info_conflict;
718 }
719 }
720 }
721 assert(result.is_valid_state(), "checking that CTS merge maintains legal state");
722
723 return result;
724 }
725
726 // Merge the variable state for locals and stack from cts into bbts.
727 bool GenerateOopMap::merge_local_state_vectors(CellTypeState* cts,
728 CellTypeState* bbts) {
729 int i;
730 int len = _max_locals + _stack_top;
731 bool change = false;
732
733 for (i = len - 1; i >= 0; i--) {
734 CellTypeState v = cts[i].merge(bbts[i], i);
735 change = change || !v.equal(bbts[i]);
736 bbts[i] = v;
737 }
738
739 return change;
740 }
741
742 // Merge the monitor stack state from cts into bbts.
743 bool GenerateOopMap::merge_monitor_state_vectors(CellTypeState* cts,
744 CellTypeState* bbts) {
745 bool change = false;
746 if (_max_monitors > 0 && _monitor_top != bad_monitors) {
747 // If there are no monitors in the program, or there has been
748 // a monitor matching error before this point in the program,
749 // then we do not merge in the monitor state.
750
751 int base = _max_locals + _max_stack;
752 int len = base + _monitor_top;
753 for (int i = len - 1; i >= base; i--) {
754 CellTypeState v = cts[i].merge(bbts[i], i);
755
756 // Can we prove that, when there has been a change, it will already
757 // have been detected at this point? That would make this equal
758 // check here unnecessary.
759 change = change || !v.equal(bbts[i]);
760 bbts[i] = v;
761 }
762 }
763
764 return change;
765 }
766
767 void GenerateOopMap::copy_state(CellTypeState *dst, CellTypeState *src) {
768 int len = _max_locals + _stack_top;
769 for (int i = 0; i < len; i++) {
770 if (src[i].is_nonlock_reference()) {
771 dst[i] = CellTypeState::make_slot_ref(i);
772 } else {
773 dst[i] = src[i];
774 }
775 }
776 if (_max_monitors > 0 && _monitor_top != bad_monitors) {
777 int base = _max_locals + _max_stack;
778 len = base + _monitor_top;
779 for (int i = base; i < len; i++) {
780 dst[i] = src[i];
781 }
782 }
783 }
784
785
786 // Merge the states for the current block and the next. As long as a
787 // block is reachable the locals and stack must be merged. If the
788 // stack heights don't match then this is a verification error and
789 // it's impossible to interpret the code. Simultaneously monitor
790 // states are being check to see if they nest statically. If monitor
791 // depths match up then their states are merged. Otherwise the
792 // mismatch is simply recorded and interpretation continues since
793 // monitor matching is purely informational and doesn't say anything
794 // about the correctness of the code.
795 void GenerateOopMap::merge_state_into_bb(BasicBlock *bb) {
796 guarantee(bb != NULL, "null basicblock");
797 assert(bb->is_alive(), "merging state into a dead basicblock");
798
799 if (_stack_top == bb->_stack_top) {
800 // always merge local state even if monitors don't match.
801 if (merge_local_state_vectors(_state, bb->_state)) {
802 bb->set_changed(true);
803 }
804 if (_monitor_top == bb->_monitor_top) {
805 // monitors still match so continue merging monitor states.
806 if (merge_monitor_state_vectors(_state, bb->_state)) {
807 bb->set_changed(true);
808 }
809 } else {
810 if (log_is_enabled(Info, monitormismatch)) {
811 report_monitor_mismatch("monitor stack height merge conflict");
812 }
813 // When the monitor stacks are not matched, we set _monitor_top to
814 // bad_monitors. This signals that, from here on, the monitor stack cannot
815 // be trusted. In particular, monitorexit bytecodes may throw
816 // exceptions. We mark this block as changed so that the change
817 // propagates properly.
818 bb->_monitor_top = bad_monitors;
819 bb->set_changed(true);
820 _monitor_safe = false;
821 }
822 } else if (!bb->is_reachable()) {
823 // First time we look at this BB
824 copy_state(bb->_state, _state);
825 bb->_stack_top = _stack_top;
826 bb->_monitor_top = _monitor_top;
827 bb->set_changed(true);
828 } else {
829 verify_error("stack height conflict: %d vs. %d", _stack_top, bb->_stack_top);
830 }
831 }
832
833 void GenerateOopMap::merge_state(GenerateOopMap *gom, int bci, int* data) {
834 gom->merge_state_into_bb(gom->get_basic_block_at(bci));
835 }
836
837 void GenerateOopMap::set_var(int localNo, CellTypeState cts) {
838 assert(cts.is_reference() || cts.is_value() || cts.is_address(),
839 "wrong celltypestate");
840 if (localNo < 0 || localNo > _max_locals) {
841 verify_error("variable write error: r%d", localNo);
842 return;
843 }
844 vars()[localNo] = cts;
845 }
846
847 CellTypeState GenerateOopMap::get_var(int localNo) {
848 assert(localNo < _max_locals + _nof_refval_conflicts, "variable read error");
849 if (localNo < 0 || localNo > _max_locals) {
850 verify_error("variable read error: r%d", localNo);
851 return valCTS; // just to pick something;
852 }
853 return vars()[localNo];
854 }
855
856 CellTypeState GenerateOopMap::pop() {
857 if ( _stack_top <= 0) {
858 verify_error("stack underflow");
859 return valCTS; // just to pick something
860 }
861 return stack()[--_stack_top];
862 }
863
864 void GenerateOopMap::push(CellTypeState cts) {
865 if ( _stack_top >= _max_stack) {
866 verify_error("stack overflow");
867 return;
868 }
869 stack()[_stack_top++] = cts;
870 }
871
872 CellTypeState GenerateOopMap::monitor_pop() {
873 assert(_monitor_top != bad_monitors, "monitor_pop called on error monitor stack");
874 if (_monitor_top == 0) {
875 // We have detected a pop of an empty monitor stack.
876 _monitor_safe = false;
877 _monitor_top = bad_monitors;
878
879 if (log_is_enabled(Info, monitormismatch)) {
880 report_monitor_mismatch("monitor stack underflow");
881 }
882 return CellTypeState::ref; // just to keep the analysis going.
883 }
884 return monitors()[--_monitor_top];
885 }
886
887 void GenerateOopMap::monitor_push(CellTypeState cts) {
888 assert(_monitor_top != bad_monitors, "monitor_push called on error monitor stack");
889 if (_monitor_top >= _max_monitors) {
890 // Some monitorenter is being executed more than once.
891 // This means that the monitor stack cannot be simulated.
892 _monitor_safe = false;
893 _monitor_top = bad_monitors;
894
895 if (log_is_enabled(Info, monitormismatch)) {
896 report_monitor_mismatch("monitor stack overflow");
897 }
898 return;
899 }
900 monitors()[_monitor_top++] = cts;
901 }
902
903 //
904 // Interpretation handling methods
905 //
906
907 void GenerateOopMap::do_interpretation()
908 {
909 // "i" is just for debugging, so we can detect cases where this loop is
910 // iterated more than once.
911 int i = 0;
912 do {
913 #ifndef PRODUCT
914 if (TraceNewOopMapGeneration) {
915 tty->print("\n\nIteration #%d of do_interpretation loop, method:\n", i);
916 method()->print_name(tty);
917 tty->print("\n\n");
918 }
919 #endif
920 _conflict = false;
921 _monitor_safe = true;
922 // init_state is now called from init_basic_blocks. The length of a
923 // state vector cannot be determined until we have made a pass through
924 // the bytecodes counting the possible monitor entries.
925 if (!_got_error) init_basic_blocks();
926 if (!_got_error) setup_method_entry_state();
927 if (!_got_error) interp_all();
928 if (!_got_error) rewrite_refval_conflicts();
929 i++;
930 } while (_conflict && !_got_error);
931 }
932
933 void GenerateOopMap::init_basic_blocks() {
934 // Note: Could consider reserving only the needed space for each BB's state
935 // (entry stack may not be of maximal height for every basic block).
936 // But cumbersome since we don't know the stack heights yet. (Nor the
937 // monitor stack heights...)
938
939 ALLOC_RESOURCE_ARRAY(_basic_blocks, BasicBlock, _bb_count);
940
941 // Make a pass through the bytecodes. Count the number of monitorenters.
942 // This can be used an upper bound on the monitor stack depth in programs
943 // which obey stack discipline with their monitor usage. Initialize the
944 // known information about basic blocks.
945 BytecodeStream j(_method);
946 Bytecodes::Code bytecode;
947
948 int bbNo = 0;
949 int monitor_count = 0;
950 int prev_bci = -1;
951 while( (bytecode = j.next()) >= 0) {
952 if (j.code() == Bytecodes::_monitorenter) {
953 monitor_count++;
954 }
955
956 int bci = j.bci();
957 if (is_bb_header(bci)) {
958 // Initialize the basicblock structure
959 BasicBlock *bb = _basic_blocks + bbNo;
960 bb->_bci = bci;
961 bb->_max_locals = _max_locals;
962 bb->_max_stack = _max_stack;
963 bb->set_changed(false);
964 bb->_stack_top = BasicBlock::_dead_basic_block; // Initialize all basicblocks are dead.
965 bb->_monitor_top = bad_monitors;
966
967 if (bbNo > 0) {
968 _basic_blocks[bbNo - 1]._end_bci = prev_bci;
969 }
970
971 bbNo++;
972 }
973 // Remember prevous bci.
974 prev_bci = bci;
975 }
976 // Set
977 _basic_blocks[bbNo-1]._end_bci = prev_bci;
978
979
980 // Check that the correct number of basicblocks was found
981 if (bbNo !=_bb_count) {
982 if (bbNo < _bb_count) {
983 verify_error("jump into the middle of instruction?");
984 return;
985 } else {
986 verify_error("extra basic blocks - should not happen?");
987 return;
988 }
989 }
990
991 _max_monitors = monitor_count;
992
993 // Now that we have a bound on the depth of the monitor stack, we can
994 // initialize the CellTypeState-related information.
995 init_state();
996
997 // We allocate space for all state-vectors for all basicblocks in one huge
998 // chunk. Then in the next part of the code, we set a pointer in each
999 // _basic_block that points to each piece.
1000
1001 // The product of bbNo and _state_len can get large if there are lots of
1002 // basic blocks and stack/locals/monitors. Need to check to make sure
1003 // we don't overflow the capacity of a pointer.
1004 if ((unsigned)bbNo > UINTPTR_MAX / sizeof(CellTypeState) / _state_len) {
1005 report_error("The amount of memory required to analyze this method "
1006 "exceeds addressable range");
1007 return;
1008 }
1009
1010 CellTypeState *basicBlockState;
1011 ALLOC_RESOURCE_ARRAY(basicBlockState, CellTypeState, bbNo * _state_len);
1012 memset(basicBlockState, 0, bbNo * _state_len * sizeof(CellTypeState));
1013
1014 // Make a pass over the basicblocks and assign their state vectors.
1015 for (int blockNum=0; blockNum < bbNo; blockNum++) {
1016 BasicBlock *bb = _basic_blocks + blockNum;
1017 bb->_state = basicBlockState + blockNum * _state_len;
1018
1019 #ifdef ASSERT
1020 if (blockNum + 1 < bbNo) {
1021 address bcp = _method->bcp_from(bb->_end_bci);
1022 int bc_len = Bytecodes::java_length_at(_method(), bcp);
1023 assert(bb->_end_bci + bc_len == bb[1]._bci, "unmatched bci info in basicblock");
1024 }
1025 #endif
1026 }
1027 #ifdef ASSERT
1028 { BasicBlock *bb = &_basic_blocks[bbNo-1];
1029 address bcp = _method->bcp_from(bb->_end_bci);
1030 int bc_len = Bytecodes::java_length_at(_method(), bcp);
1031 assert(bb->_end_bci + bc_len == _method->code_size(), "wrong end bci");
1032 }
1033 #endif
1034
1035 // Mark all alive blocks
1036 mark_reachable_code();
1037 }
1038
1039 void GenerateOopMap::setup_method_entry_state() {
1040
1041 // Initialize all locals to 'uninit' and set stack-height to 0
1042 make_context_uninitialized();
1043
1044 // Initialize CellState type of arguments
1045 methodsig_to_effect(method()->signature(), method()->is_static(), vars());
1046
1047 // If some references must be pre-assigned to null, then set that up
1048 initialize_vars();
1049
1050 // This is the start state
1051 merge_state_into_bb(&_basic_blocks[0]);
1052
1053 assert(_basic_blocks[0].changed(), "we are not getting off the ground");
1054 }
1055
1056 // The instruction at bci is changing size by "delta". Update the basic blocks.
1057 void GenerateOopMap::update_basic_blocks(int bci, int delta,
1058 int new_method_size) {
1059 assert(new_method_size >= method()->code_size() + delta,
1060 "new method size is too small");
1061
1062 _bb_hdr_bits.reinitialize(new_method_size);
1063
1064 for(int k = 0; k < _bb_count; k++) {
1065 if (_basic_blocks[k]._bci > bci) {
1066 _basic_blocks[k]._bci += delta;
1067 _basic_blocks[k]._end_bci += delta;
1068 }
1069 _bb_hdr_bits.at_put(_basic_blocks[k]._bci, true);
1070 }
1071 }
1072
1073 //
1074 // Initvars handling
1075 //
1076
1077 void GenerateOopMap::initialize_vars() {
1078 for (int k = 0; k < _init_vars->length(); k++)
1079 _state[_init_vars->at(k)] = CellTypeState::make_slot_ref(k);
1080 }
1081
1082 void GenerateOopMap::add_to_ref_init_set(int localNo) {
1083
1084 if (TraceNewOopMapGeneration)
1085 tty->print_cr("Added init vars: %d", localNo);
1086
1087 // Is it already in the set?
1088 if (_init_vars->contains(localNo) )
1089 return;
1090
1091 _init_vars->append(localNo);
1092 }
1093
1094 //
1095 // Interpreration code
1096 //
1097
1098 void GenerateOopMap::interp_all() {
1099 bool change = true;
1100
1101 while (change && !_got_error) {
1102 change = false;
1103 for (int i = 0; i < _bb_count && !_got_error; i++) {
1104 BasicBlock *bb = &_basic_blocks[i];
1105 if (bb->changed()) {
1106 if (_got_error) return;
1107 change = true;
1108 bb->set_changed(false);
1109 interp_bb(bb);
1110 }
1111 }
1112 }
1113 }
1114
1115 void GenerateOopMap::interp_bb(BasicBlock *bb) {
1116
1117 // We do not want to do anything in case the basic-block has not been initialized. This
1118 // will happen in the case where there is dead-code hang around in a method.
1119 assert(bb->is_reachable(), "should be reachable or deadcode exist");
1120 restore_state(bb);
1121
1122 BytecodeStream itr(_method);
1123
1124 // Set iterator interval to be the current basicblock
1125 int lim_bci = next_bb_start_pc(bb);
1126 itr.set_interval(bb->_bci, lim_bci);
1127 assert(lim_bci != bb->_bci, "must be at least one instruction in a basicblock");
1128 itr.next(); // read first instruction
1129
1130 // Iterates through all bytecodes except the last in a basic block.
1131 // We handle the last one special, since there is controlflow change.
1132 while(itr.next_bci() < lim_bci && !_got_error) {
1133 if (_has_exceptions || _monitor_top != 0) {
1134 // We do not need to interpret the results of exceptional
1135 // continuation from this instruction when the method has no
1136 // exception handlers and the monitor stack is currently
1137 // empty.
1138 do_exception_edge(&itr);
1139 }
1140 interp1(&itr);
1141 itr.next();
1142 }
1143
1144 // Handle last instruction.
1145 if (!_got_error) {
1146 assert(itr.next_bci() == lim_bci, "must point to end");
1147 if (_has_exceptions || _monitor_top != 0) {
1148 do_exception_edge(&itr);
1149 }
1150 interp1(&itr);
1151
1152 bool fall_through = jump_targets_do(&itr, GenerateOopMap::merge_state, NULL);
1153 if (_got_error) return;
1154
1155 if (itr.code() == Bytecodes::_ret) {
1156 assert(!fall_through, "cannot be set if ret instruction");
1157 // Automatically handles 'wide' ret indicies
1158 ret_jump_targets_do(&itr, GenerateOopMap::merge_state, itr.get_index(), NULL);
1159 } else if (fall_through) {
1160 // Hit end of BB, but the instr. was a fall-through instruction,
1161 // so perform transition as if the BB ended in a "jump".
1162 if (lim_bci != bb[1]._bci) {
1163 verify_error("bytecodes fell through last instruction");
1164 return;
1165 }
1166 merge_state_into_bb(bb + 1);
1167 }
1168 }
1169 }
1170
1171 void GenerateOopMap::do_exception_edge(BytecodeStream* itr) {
1172 // Only check exception edge, if bytecode can trap
1173 if (!Bytecodes::can_trap(itr->code())) return;
1174 switch (itr->code()) {
1175 case Bytecodes::_aload_0:
1176 // These bytecodes can trap for rewriting. We need to assume that
1177 // they do not throw exceptions to make the monitor analysis work.
1178 return;
1179
1180 case Bytecodes::_ireturn:
1181 case Bytecodes::_lreturn:
1182 case Bytecodes::_freturn:
1183 case Bytecodes::_dreturn:
1184 case Bytecodes::_areturn:
1185 case Bytecodes::_return:
1186 // If the monitor stack height is not zero when we leave the method,
1187 // then we are either exiting with a non-empty stack or we have
1188 // found monitor trouble earlier in our analysis. In either case,
1189 // assume an exception could be taken here.
1190 if (_monitor_top == 0) {
1191 return;
1192 }
1193 break;
1194
1195 case Bytecodes::_monitorexit:
1196 // If the monitor stack height is bad_monitors, then we have detected a
1197 // monitor matching problem earlier in the analysis. If the
1198 // monitor stack height is 0, we are about to pop a monitor
1199 // off of an empty stack. In either case, the bytecode
1200 // could throw an exception.
1201 if (_monitor_top != bad_monitors && _monitor_top != 0) {
1202 return;
1203 }
1204 break;
1205
1206 default:
1207 break;
1208 }
1209
1210 if (_has_exceptions) {
1211 int bci = itr->bci();
1212 ExceptionTable exct(method());
1213 for(int i = 0; i< exct.length(); i++) {
1214 int start_pc = exct.start_pc(i);
1215 int end_pc = exct.end_pc(i);
1216 int handler_pc = exct.handler_pc(i);
1217 int catch_type = exct.catch_type_index(i);
1218
1219 if (start_pc <= bci && bci < end_pc) {
1220 BasicBlock *excBB = get_basic_block_at(handler_pc);
1221 guarantee(excBB != NULL, "no basic block for exception");
1222 CellTypeState *excStk = excBB->stack();
1223 CellTypeState *cOpStck = stack();
1224 CellTypeState cOpStck_0 = cOpStck[0];
1225 int cOpStackTop = _stack_top;
1226
1227 // Exception stacks are always the same.
1228 assert(method()->max_stack() > 0, "sanity check");
1229
1230 // We remembered the size and first element of "cOpStck"
1231 // above; now we temporarily set them to the appropriate
1232 // values for an exception handler. */
1233 cOpStck[0] = CellTypeState::make_slot_ref(_max_locals);
1234 _stack_top = 1;
1235
1236 merge_state_into_bb(excBB);
1237
1238 // Now undo the temporary change.
1239 cOpStck[0] = cOpStck_0;
1240 _stack_top = cOpStackTop;
1241
1242 // If this is a "catch all" handler, then we do not need to
1243 // consider any additional handlers.
1244 if (catch_type == 0) {
1245 return;
1246 }
1247 }
1248 }
1249 }
1250
1251 // It is possible that none of the exception handlers would have caught
1252 // the exception. In this case, we will exit the method. We must
1253 // ensure that the monitor stack is empty in this case.
1254 if (_monitor_top == 0) {
1255 return;
1256 }
1257
1258 // We pessimistically assume that this exception can escape the
1259 // method. (It is possible that it will always be caught, but
1260 // we don't care to analyse the types of the catch clauses.)
1261
1262 // We don't set _monitor_top to bad_monitors because there are no successors
1263 // to this exceptional exit.
1264
1265 if (log_is_enabled(Info, monitormismatch) && _monitor_safe) {
1266 // We check _monitor_safe so that we only report the first mismatched
1267 // exceptional exit.
1268 report_monitor_mismatch("non-empty monitor stack at exceptional exit");
1269 }
1270 _monitor_safe = false;
1271
1272 }
1273
1274 void GenerateOopMap::report_monitor_mismatch(const char *msg) {
1275 ResourceMark rm;
1276 LogStream ls(Log(monitormismatch)::info());
1277 ls.print("Monitor mismatch in method ");
1278 method()->print_short_name(&ls);
1279 ls.print_cr(": %s", msg);
1280 }
1281
1282 void GenerateOopMap::print_states(outputStream *os,
1283 CellTypeState* vec, int num) {
1284 for (int i = 0; i < num; i++) {
1285 vec[i].print(tty);
1286 }
1287 }
1288
1289 // Print the state values at the current bytecode.
1290 void GenerateOopMap::print_current_state(outputStream *os,
1291 BytecodeStream *currentBC,
1292 bool detailed) {
1293 if (detailed) {
1294 os->print(" %4d vars = ", currentBC->bci());
1295 print_states(os, vars(), _max_locals);
1296 os->print(" %s", Bytecodes::name(currentBC->code()));
1297 } else {
1298 os->print(" %4d vars = '%s' ", currentBC->bci(), state_vec_to_string(vars(), _max_locals));
1299 os->print(" stack = '%s' ", state_vec_to_string(stack(), _stack_top));
1300 if (_monitor_top != bad_monitors) {
1301 os->print(" monitors = '%s' \t%s", state_vec_to_string(monitors(), _monitor_top), Bytecodes::name(currentBC->code()));
1302 } else {
1303 os->print(" [bad monitor stack]");
1304 }
1305 }
1306
1307 switch(currentBC->code()) {
1308 case Bytecodes::_invokevirtual:
1309 case Bytecodes::_invokespecial:
1310 case Bytecodes::_invokestatic:
1311 case Bytecodes::_invokedynamic:
1312 case Bytecodes::_invokeinterface: {
1313 int idx = currentBC->has_index_u4() ? currentBC->get_index_u4() : currentBC->get_index_u2_cpcache();
1314 ConstantPool* cp = method()->constants();
1315 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
1316 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1317 Symbol* signature = cp->symbol_at(signatureIdx);
1318 os->print("%s", signature->as_C_string());
1319 }
1320 default:
1321 break;
1322 }
1323
1324 if (detailed) {
1325 os->cr();
1326 os->print(" stack = ");
1327 print_states(os, stack(), _stack_top);
1328 os->cr();
1329 if (_monitor_top != bad_monitors) {
1330 os->print(" monitors = ");
1331 print_states(os, monitors(), _monitor_top);
1332 } else {
1333 os->print(" [bad monitor stack]");
1334 }
1335 }
1336
1337 os->cr();
1338 }
1339
1340 // Sets the current state to be the state after executing the
1341 // current instruction, starting in the current state.
1342 void GenerateOopMap::interp1(BytecodeStream *itr) {
1343 if (TraceNewOopMapGeneration) {
1344 print_current_state(tty, itr, TraceNewOopMapGenerationDetailed);
1345 }
1346
1347 // Should we report the results? Result is reported *before* the instruction at the current bci is executed.
1348 // However, not for calls. For calls we do not want to include the arguments, so we postpone the reporting until
1349 // they have been popped (in method ppl).
1350 if (_report_result == true) {
1351 switch(itr->code()) {
1352 case Bytecodes::_invokevirtual:
1353 case Bytecodes::_invokespecial:
1354 case Bytecodes::_invokestatic:
1355 case Bytecodes::_invokedynamic:
1356 case Bytecodes::_invokeinterface:
1357 _itr_send = itr;
1358 _report_result_for_send = true;
1359 break;
1360 default:
1361 fill_stackmap_for_opcodes(itr, vars(), stack(), _stack_top);
1362 break;
1363 }
1364 }
1365
1366 // abstract interpretation of current opcode
1367 switch(itr->code()) {
1368 case Bytecodes::_nop: break;
1369 case Bytecodes::_goto: break;
1370 case Bytecodes::_goto_w: break;
1371 case Bytecodes::_iinc: break;
1372 case Bytecodes::_return: do_return_monitor_check();
1373 break;
1374
1375 case Bytecodes::_aconst_null:
1376 case Bytecodes::_new: ppush1(CellTypeState::make_line_ref(itr->bci()));
1377 break;
1378
1379 case Bytecodes::_defaultvalue: ppush1(CellTypeState::make_line_ref(itr->bci())); break;
1380 case Bytecodes::_withfield: do_withfield(itr->get_index_u2_cpcache(), itr->bci()); break;
1381
1382 case Bytecodes::_iconst_m1:
1383 case Bytecodes::_iconst_0:
1384 case Bytecodes::_iconst_1:
1385 case Bytecodes::_iconst_2:
1386 case Bytecodes::_iconst_3:
1387 case Bytecodes::_iconst_4:
1388 case Bytecodes::_iconst_5:
1389 case Bytecodes::_fconst_0:
1390 case Bytecodes::_fconst_1:
1391 case Bytecodes::_fconst_2:
1392 case Bytecodes::_bipush:
1393 case Bytecodes::_sipush: ppush1(valCTS); break;
1394
1395 case Bytecodes::_lconst_0:
1396 case Bytecodes::_lconst_1:
1397 case Bytecodes::_dconst_0:
1398 case Bytecodes::_dconst_1: ppush(vvCTS); break;
1399
1400 case Bytecodes::_ldc2_w: ppush(vvCTS); break;
1401
1402 case Bytecodes::_ldc: // fall through:
1403 case Bytecodes::_ldc_w: do_ldc(itr->bci()); break;
1404
1405 case Bytecodes::_iload:
1406 case Bytecodes::_fload: ppload(vCTS, itr->get_index()); break;
1407
1408 case Bytecodes::_lload:
1409 case Bytecodes::_dload: ppload(vvCTS,itr->get_index()); break;
1410
1411 case Bytecodes::_aload: ppload(rCTS, itr->get_index()); break;
1412
1413 case Bytecodes::_iload_0:
1414 case Bytecodes::_fload_0: ppload(vCTS, 0); break;
1415 case Bytecodes::_iload_1:
1416 case Bytecodes::_fload_1: ppload(vCTS, 1); break;
1417 case Bytecodes::_iload_2:
1418 case Bytecodes::_fload_2: ppload(vCTS, 2); break;
1419 case Bytecodes::_iload_3:
1420 case Bytecodes::_fload_3: ppload(vCTS, 3); break;
1421
1422 case Bytecodes::_lload_0:
1423 case Bytecodes::_dload_0: ppload(vvCTS, 0); break;
1424 case Bytecodes::_lload_1:
1425 case Bytecodes::_dload_1: ppload(vvCTS, 1); break;
1426 case Bytecodes::_lload_2:
1427 case Bytecodes::_dload_2: ppload(vvCTS, 2); break;
1428 case Bytecodes::_lload_3:
1429 case Bytecodes::_dload_3: ppload(vvCTS, 3); break;
1430
1431 case Bytecodes::_aload_0: ppload(rCTS, 0); break;
1432 case Bytecodes::_aload_1: ppload(rCTS, 1); break;
1433 case Bytecodes::_aload_2: ppload(rCTS, 2); break;
1434 case Bytecodes::_aload_3: ppload(rCTS, 3); break;
1435
1436 case Bytecodes::_iaload:
1437 case Bytecodes::_faload:
1438 case Bytecodes::_baload:
1439 case Bytecodes::_caload:
1440 case Bytecodes::_saload: pp(vrCTS, vCTS); break;
1441
1442 case Bytecodes::_laload: pp(vrCTS, vvCTS); break;
1443 case Bytecodes::_daload: pp(vrCTS, vvCTS); break;
1444
1445 case Bytecodes::_aaload: pp_new_ref(vrCTS, itr->bci()); break;
1446
1447 case Bytecodes::_istore:
1448 case Bytecodes::_fstore: ppstore(vCTS, itr->get_index()); break;
1449
1450 case Bytecodes::_lstore:
1451 case Bytecodes::_dstore: ppstore(vvCTS, itr->get_index()); break;
1452
1453 case Bytecodes::_astore: do_astore(itr->get_index()); break;
1454
1455 case Bytecodes::_istore_0:
1456 case Bytecodes::_fstore_0: ppstore(vCTS, 0); break;
1457 case Bytecodes::_istore_1:
1458 case Bytecodes::_fstore_1: ppstore(vCTS, 1); break;
1459 case Bytecodes::_istore_2:
1460 case Bytecodes::_fstore_2: ppstore(vCTS, 2); break;
1461 case Bytecodes::_istore_3:
1462 case Bytecodes::_fstore_3: ppstore(vCTS, 3); break;
1463
1464 case Bytecodes::_lstore_0:
1465 case Bytecodes::_dstore_0: ppstore(vvCTS, 0); break;
1466 case Bytecodes::_lstore_1:
1467 case Bytecodes::_dstore_1: ppstore(vvCTS, 1); break;
1468 case Bytecodes::_lstore_2:
1469 case Bytecodes::_dstore_2: ppstore(vvCTS, 2); break;
1470 case Bytecodes::_lstore_3:
1471 case Bytecodes::_dstore_3: ppstore(vvCTS, 3); break;
1472
1473 case Bytecodes::_astore_0: do_astore(0); break;
1474 case Bytecodes::_astore_1: do_astore(1); break;
1475 case Bytecodes::_astore_2: do_astore(2); break;
1476 case Bytecodes::_astore_3: do_astore(3); break;
1477
1478 case Bytecodes::_iastore:
1479 case Bytecodes::_fastore:
1480 case Bytecodes::_bastore:
1481 case Bytecodes::_castore:
1482 case Bytecodes::_sastore: ppop(vvrCTS); break;
1483 case Bytecodes::_lastore:
1484 case Bytecodes::_dastore: ppop(vvvrCTS); break;
1485 case Bytecodes::_aastore: ppop(rvrCTS); break;
1486
1487 case Bytecodes::_pop: ppop_any(1); break;
1488 case Bytecodes::_pop2: ppop_any(2); break;
1489
1490 case Bytecodes::_dup: ppdupswap(1, "11"); break;
1491 case Bytecodes::_dup_x1: ppdupswap(2, "121"); break;
1492 case Bytecodes::_dup_x2: ppdupswap(3, "1321"); break;
1493 case Bytecodes::_dup2: ppdupswap(2, "2121"); break;
1494 case Bytecodes::_dup2_x1: ppdupswap(3, "21321"); break;
1495 case Bytecodes::_dup2_x2: ppdupswap(4, "214321"); break;
1496 case Bytecodes::_swap: ppdupswap(2, "12"); break;
1497
1498 case Bytecodes::_iadd:
1499 case Bytecodes::_fadd:
1500 case Bytecodes::_isub:
1501 case Bytecodes::_fsub:
1502 case Bytecodes::_imul:
1503 case Bytecodes::_fmul:
1504 case Bytecodes::_idiv:
1505 case Bytecodes::_fdiv:
1506 case Bytecodes::_irem:
1507 case Bytecodes::_frem:
1508 case Bytecodes::_ishl:
1509 case Bytecodes::_ishr:
1510 case Bytecodes::_iushr:
1511 case Bytecodes::_iand:
1512 case Bytecodes::_ior:
1513 case Bytecodes::_ixor:
1514 case Bytecodes::_l2f:
1515 case Bytecodes::_l2i:
1516 case Bytecodes::_d2f:
1517 case Bytecodes::_d2i:
1518 case Bytecodes::_fcmpl:
1519 case Bytecodes::_fcmpg: pp(vvCTS, vCTS); break;
1520
1521 case Bytecodes::_ladd:
1522 case Bytecodes::_dadd:
1523 case Bytecodes::_lsub:
1524 case Bytecodes::_dsub:
1525 case Bytecodes::_lmul:
1526 case Bytecodes::_dmul:
1527 case Bytecodes::_ldiv:
1528 case Bytecodes::_ddiv:
1529 case Bytecodes::_lrem:
1530 case Bytecodes::_drem:
1531 case Bytecodes::_land:
1532 case Bytecodes::_lor:
1533 case Bytecodes::_lxor: pp(vvvvCTS, vvCTS); break;
1534
1535 case Bytecodes::_ineg:
1536 case Bytecodes::_fneg:
1537 case Bytecodes::_i2f:
1538 case Bytecodes::_f2i:
1539 case Bytecodes::_i2c:
1540 case Bytecodes::_i2s:
1541 case Bytecodes::_i2b: pp(vCTS, vCTS); break;
1542
1543 case Bytecodes::_lneg:
1544 case Bytecodes::_dneg:
1545 case Bytecodes::_l2d:
1546 case Bytecodes::_d2l: pp(vvCTS, vvCTS); break;
1547
1548 case Bytecodes::_lshl:
1549 case Bytecodes::_lshr:
1550 case Bytecodes::_lushr: pp(vvvCTS, vvCTS); break;
1551
1552 case Bytecodes::_i2l:
1553 case Bytecodes::_i2d:
1554 case Bytecodes::_f2l:
1555 case Bytecodes::_f2d: pp(vCTS, vvCTS); break;
1556
1557 case Bytecodes::_lcmp: pp(vvvvCTS, vCTS); break;
1558 case Bytecodes::_dcmpl:
1559 case Bytecodes::_dcmpg: pp(vvvvCTS, vCTS); break;
1560
1561 case Bytecodes::_ifeq:
1562 case Bytecodes::_ifne:
1563 case Bytecodes::_iflt:
1564 case Bytecodes::_ifge:
1565 case Bytecodes::_ifgt:
1566 case Bytecodes::_ifle:
1567 case Bytecodes::_tableswitch: ppop1(valCTS);
1568 break;
1569 case Bytecodes::_ireturn:
1570 case Bytecodes::_freturn: do_return_monitor_check();
1571 ppop1(valCTS);
1572 break;
1573 case Bytecodes::_if_icmpeq:
1574 case Bytecodes::_if_icmpne:
1575 case Bytecodes::_if_icmplt:
1576 case Bytecodes::_if_icmpge:
1577 case Bytecodes::_if_icmpgt:
1578 case Bytecodes::_if_icmple: ppop(vvCTS);
1579 break;
1580
1581 case Bytecodes::_lreturn: do_return_monitor_check();
1582 ppop(vvCTS);
1583 break;
1584
1585 case Bytecodes::_dreturn: do_return_monitor_check();
1586 ppop(vvCTS);
1587 break;
1588
1589 case Bytecodes::_if_acmpeq:
1590 case Bytecodes::_if_acmpne: ppop(rrCTS); break;
1591
1592 case Bytecodes::_jsr: do_jsr(itr->dest()); break;
1593 case Bytecodes::_jsr_w: do_jsr(itr->dest_w()); break;
1594
1595 case Bytecodes::_getstatic: do_field(true, true, itr->get_index_u2_cpcache(), itr->bci()); break;
1596 case Bytecodes::_putstatic: do_field(false, true, itr->get_index_u2_cpcache(), itr->bci()); break;
1597 case Bytecodes::_getfield: do_field(true, false, itr->get_index_u2_cpcache(), itr->bci()); break;
1598 case Bytecodes::_putfield: do_field(false, false, itr->get_index_u2_cpcache(), itr->bci()); break;
1599
1600 case Bytecodes::_invokeinterface:
1601 case Bytecodes::_invokevirtual:
1602 case Bytecodes::_invokespecial: do_method(false, itr->get_index_u2_cpcache(), itr->bci()); break;
1603 case Bytecodes::_invokestatic: do_method(true , itr->get_index_u2_cpcache(), itr->bci()); break;
1604 case Bytecodes::_invokedynamic: do_method(true , itr->get_index_u4(), itr->bci()); break;
1605 case Bytecodes::_newarray:
1606 case Bytecodes::_anewarray: pp_new_ref(vCTS, itr->bci()); break;
1607 case Bytecodes::_checkcast: do_checkcast(); break;
1608 case Bytecodes::_arraylength:
1609 case Bytecodes::_instanceof: pp(rCTS, vCTS); break;
1610 case Bytecodes::_monitorenter: do_monitorenter(itr->bci()); break;
1611 case Bytecodes::_monitorexit: do_monitorexit(itr->bci()); break;
1612
1613 case Bytecodes::_athrow: // handled by do_exception_edge() BUT ...
1614 // vlh(apple): do_exception_edge() does not get
1615 // called if method has no exception handlers
1616 if ((!_has_exceptions) && (_monitor_top > 0)) {
1617 _monitor_safe = false;
1618 }
1619 break;
1620
1621 case Bytecodes::_areturn: do_return_monitor_check();
1622 ppop1(refCTS);
1623 break;
1624
1625 case Bytecodes::_ifnull:
1626 case Bytecodes::_ifnonnull: ppop1(refCTS); break;
1627 case Bytecodes::_multianewarray: do_multianewarray(*(itr->bcp()+3), itr->bci()); break;
1628
1629 case Bytecodes::_wide: fatal("Iterator should skip this bytecode"); break;
1630 case Bytecodes::_ret: break;
1631
1632 // Java opcodes
1633 case Bytecodes::_lookupswitch: ppop1(valCTS); break;
1634
1635 default:
1636 tty->print("unexpected opcode: %d\n", itr->code());
1637 ShouldNotReachHere();
1638 break;
1639 }
1640 }
1641
1642 void GenerateOopMap::check_type(CellTypeState expected, CellTypeState actual) {
1643 if (!expected.equal_kind(actual)) {
1644 verify_error("wrong type on stack (found: %c expected: %c)", actual.to_char(), expected.to_char());
1645 }
1646 }
1647
1648 void GenerateOopMap::ppstore(CellTypeState *in, int loc_no) {
1649 while(!(*in).is_bottom()) {
1650 CellTypeState expected =*in++;
1651 CellTypeState actual = pop();
1652 check_type(expected, actual);
1653 assert(loc_no >= 0, "sanity check");
1654 set_var(loc_no++, actual);
1655 }
1656 }
1657
1658 void GenerateOopMap::ppload(CellTypeState *out, int loc_no) {
1659 while(!(*out).is_bottom()) {
1660 CellTypeState out1 = *out++;
1661 CellTypeState vcts = get_var(loc_no);
1662 assert(out1.can_be_reference() || out1.can_be_value(),
1663 "can only load refs. and values.");
1664 if (out1.is_reference()) {
1665 assert(loc_no>=0, "sanity check");
1666 if (!vcts.is_reference()) {
1667 // We were asked to push a reference, but the type of the
1668 // variable can be something else
1669 _conflict = true;
1670 if (vcts.can_be_uninit()) {
1671 // It is a ref-uninit conflict (at least). If there are other
1672 // problems, we'll get them in the next round
1673 add_to_ref_init_set(loc_no);
1674 vcts = out1;
1675 } else {
1676 // It wasn't a ref-uninit conflict. So must be a
1677 // ref-val or ref-pc conflict. Split the variable.
1678 record_refval_conflict(loc_no);
1679 vcts = out1;
1680 }
1681 push(out1); // recover...
1682 } else {
1683 push(vcts); // preserve reference.
1684 }
1685 // Otherwise it is a conflict, but one that verification would
1686 // have caught if illegal. In particular, it can't be a topCTS
1687 // resulting from mergeing two difference pcCTS's since the verifier
1688 // would have rejected any use of such a merge.
1689 } else {
1690 push(out1); // handle val/init conflict
1691 }
1692 loc_no++;
1693 }
1694 }
1695
1696 void GenerateOopMap::ppdupswap(int poplen, const char *out) {
1697 CellTypeState actual[5];
1698 assert(poplen < 5, "this must be less than length of actual vector");
1699
1700 // Pop all arguments.
1701 for (int i = 0; i < poplen; i++) {
1702 actual[i] = pop();
1703 }
1704 // Field _state is uninitialized when calling push.
1705 for (int i = poplen; i < 5; i++) {
1706 actual[i] = CellTypeState::uninit;
1707 }
1708
1709 // put them back
1710 char push_ch = *out++;
1711 while (push_ch != '\0') {
1712 int idx = push_ch - '1';
1713 assert(idx >= 0 && idx < poplen, "wrong arguments");
1714 push(actual[idx]);
1715 push_ch = *out++;
1716 }
1717 }
1718
1719 void GenerateOopMap::ppop1(CellTypeState out) {
1720 CellTypeState actual = pop();
1721 check_type(out, actual);
1722 }
1723
1724 void GenerateOopMap::ppop(CellTypeState *out) {
1725 while (!(*out).is_bottom()) {
1726 ppop1(*out++);
1727 }
1728 }
1729
1730 void GenerateOopMap::ppush1(CellTypeState in) {
1731 assert(in.is_reference() || in.is_value(), "sanity check");
1732 push(in);
1733 }
1734
1735 void GenerateOopMap::ppush(CellTypeState *in) {
1736 while (!(*in).is_bottom()) {
1737 ppush1(*in++);
1738 }
1739 }
1740
1741 void GenerateOopMap::pp(CellTypeState *in, CellTypeState *out) {
1742 ppop(in);
1743 ppush(out);
1744 }
1745
1746 void GenerateOopMap::pp_new_ref(CellTypeState *in, int bci) {
1747 ppop(in);
1748 ppush1(CellTypeState::make_line_ref(bci));
1749 }
1750
1751 void GenerateOopMap::ppop_any(int poplen) {
1752 if (_stack_top >= poplen) {
1753 _stack_top -= poplen;
1754 } else {
1755 verify_error("stack underflow");
1756 }
1757 }
1758
1759 // Replace all occurences of the state 'match' with the state 'replace'
1760 // in our current state vector.
1761 void GenerateOopMap::replace_all_CTS_matches(CellTypeState match,
1762 CellTypeState replace) {
1763 int i;
1764 int len = _max_locals + _stack_top;
1765 bool change = false;
1766
1767 for (i = len - 1; i >= 0; i--) {
1768 if (match.equal(_state[i])) {
1769 _state[i] = replace;
1770 }
1771 }
1772
1773 if (_monitor_top > 0) {
1774 int base = _max_locals + _max_stack;
1775 len = base + _monitor_top;
1776 for (i = len - 1; i >= base; i--) {
1777 if (match.equal(_state[i])) {
1778 _state[i] = replace;
1779 }
1780 }
1781 }
1782 }
1783
1784 void GenerateOopMap::do_checkcast() {
1785 CellTypeState actual = pop();
1786 check_type(refCTS, actual);
1787 push(actual);
1788 }
1789
1790 void GenerateOopMap::do_monitorenter(int bci) {
1791 CellTypeState actual = pop();
1792 if (_monitor_top == bad_monitors) {
1793 return;
1794 }
1795
1796 // Bail out when we get repeated locks on an identical monitor. This case
1797 // isn't too hard to handle and can be made to work if supporting nested
1798 // redundant synchronized statements becomes a priority.
1799 //
1800 // See also "Note" in do_monitorexit(), below.
1801 if (actual.is_lock_reference()) {
1802 _monitor_top = bad_monitors;
1803 _monitor_safe = false;
1804
1805 if (log_is_enabled(Info, monitormismatch)) {
1806 report_monitor_mismatch("nested redundant lock -- bailout...");
1807 }
1808 return;
1809 }
1810
1811 CellTypeState lock = CellTypeState::make_lock_ref(bci);
1812 check_type(refCTS, actual);
1813 if (!actual.is_info_top()) {
1814 replace_all_CTS_matches(actual, lock);
1815 monitor_push(lock);
1816 }
1817 }
1818
1819 void GenerateOopMap::do_monitorexit(int bci) {
1820 CellTypeState actual = pop();
1821 if (_monitor_top == bad_monitors) {
1822 return;
1823 }
1824 check_type(refCTS, actual);
1825 CellTypeState expected = monitor_pop();
1826 if (!actual.is_lock_reference() || !expected.equal(actual)) {
1827 // The monitor we are exiting is not verifiably the one
1828 // on the top of our monitor stack. This causes a monitor
1829 // mismatch.
1830 _monitor_top = bad_monitors;
1831 _monitor_safe = false;
1832
1833 // We need to mark this basic block as changed so that
1834 // this monitorexit will be visited again. We need to
1835 // do this to ensure that we have accounted for the
1836 // possibility that this bytecode will throw an
1837 // exception.
1838 BasicBlock* bb = get_basic_block_containing(bci);
1839 guarantee(bb != NULL, "no basic block for bci");
1840 bb->set_changed(true);
1841 bb->_monitor_top = bad_monitors;
1842
1843 if (log_is_enabled(Info, monitormismatch)) {
1844 report_monitor_mismatch("improper monitor pair");
1845 }
1846 } else {
1847 // This code is a fix for the case where we have repeated
1848 // locking of the same object in straightline code. We clear
1849 // out the lock when it is popped from the monitor stack
1850 // and replace it with an unobtrusive reference value that can
1851 // be locked again.
1852 //
1853 // Note: when generateOopMap is fixed to properly handle repeated,
1854 // nested, redundant locks on the same object, then this
1855 // fix will need to be removed at that time.
1856 replace_all_CTS_matches(actual, CellTypeState::make_line_ref(bci));
1857 }
1858 }
1859
1860 void GenerateOopMap::do_return_monitor_check() {
1861 if (_monitor_top > 0) {
1862 // The monitor stack must be empty when we leave the method
1863 // for the monitors to be properly matched.
1864 _monitor_safe = false;
1865
1866 // Since there are no successors to the *return bytecode, it
1867 // isn't necessary to set _monitor_top to bad_monitors.
1868
1869 if (log_is_enabled(Info, monitormismatch)) {
1870 report_monitor_mismatch("non-empty monitor stack at return");
1871 }
1872 }
1873 }
1874
1875 void GenerateOopMap::do_jsr(int targ_bci) {
1876 push(CellTypeState::make_addr(targ_bci));
1877 }
1878
1879
1880
1881 void GenerateOopMap::do_ldc(int bci) {
1882 Bytecode_loadconstant ldc(method(), bci);
1883 ConstantPool* cp = method()->constants();
1884 constantTag tag = cp->tag_at(ldc.pool_index()); // idx is index in resolved_references
1885 BasicType bt = ldc.result_type();
1886 #ifdef ASSERT
1887 BasicType tag_bt = tag.is_dynamic_constant() ? bt : tag.basic_type();
1888 assert(bt == tag_bt, "same result");
1889 #endif
1890 CellTypeState cts;
1891 if (is_reference_type(bt)) { // could be T_ARRAY with condy
1892 assert(!tag.is_string_index() && !tag.is_klass_index(), "Unexpected index tag");
1893 cts = CellTypeState::make_line_ref(bci);
1894 } else {
1895 cts = valCTS;
1896 }
1897 ppush1(cts);
1898 }
1899
1900 void GenerateOopMap::do_multianewarray(int dims, int bci) {
1901 assert(dims >= 1, "sanity check");
1902 for(int i = dims -1; i >=0; i--) {
1903 ppop1(valCTS);
1904 }
1905 ppush1(CellTypeState::make_line_ref(bci));
1906 }
1907
1908 void GenerateOopMap::do_astore(int idx) {
1909 CellTypeState r_or_p = pop();
1910 if (!r_or_p.is_address() && !r_or_p.is_reference()) {
1911 // We actually expected ref or pc, but we only report that we expected a ref. It does not
1912 // really matter (at least for now)
1913 verify_error("wrong type on stack (found: %c, expected: {pr})", r_or_p.to_char());
1914 return;
1915 }
1916 set_var(idx, r_or_p);
1917 }
1918
1919 // Copies bottom/zero terminated CTS string from "src" into "dst".
1920 // Does NOT terminate with a bottom. Returns the number of cells copied.
1921 int GenerateOopMap::copy_cts(CellTypeState *dst, CellTypeState *src) {
1922 int idx = 0;
1923 while (!src[idx].is_bottom()) {
1924 dst[idx] = src[idx];
1925 idx++;
1926 }
1927 return idx;
1928 }
1929
1930 void GenerateOopMap::do_field(int is_get, int is_static, int idx, int bci) {
1931 // Dig up signature for field in constant pool
1932 ConstantPool* cp = method()->constants();
1933 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
1934 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1935 Symbol* signature = cp->symbol_at(signatureIdx);
1936
1937 // Parse signature (espcially simple for fields)
1938 assert(signature->utf8_length() > 0, "field signatures cannot have zero length");
1939 // The signature is UFT8 encoded, but the first char is always ASCII for signatures.
1940 char sigch = (char)*(signature->base());
1941 CellTypeState temp[4];
1942 CellTypeState *eff = sigchar_to_effect(sigch, bci, temp);
1943
1944 CellTypeState in[4];
1945 CellTypeState *out;
1946 int i = 0;
1947
1948 if (is_get) {
1949 out = eff;
1950 } else {
1951 out = epsilonCTS;
1952 i = copy_cts(in, eff);
1953 }
1954 if (!is_static) {
1955 in[i++] = CellTypeState::ref;
1956 }
1957 in[i] = CellTypeState::bottom;
1958 assert(i<=3, "sanity check");
1959 pp(in, out);
1960 }
1961
1962 void GenerateOopMap::do_method(int is_static, int idx, int bci) {
1963 // Dig up signature for field in constant pool
1964 ConstantPool* cp = _method->constants();
1965 Symbol* signature = cp->signature_ref_at(idx);
1966
1967 // Parse method signature
1968 CellTypeState out[4];
1969 CellTypeState in[MAXARGSIZE+1]; // Includes result
1970 ComputeCallStack cse(signature);
1971
1972 // Compute return type
1973 int res_length= cse.compute_for_returntype(out);
1974
1975 // Temporary hack.
1976 if (out[0].equal(CellTypeState::ref) && out[1].equal(CellTypeState::bottom)) {
1977 out[0] = CellTypeState::make_line_ref(bci);
1978 }
1979
1980 assert(res_length<=4, "max value should be vv");
1981
1982 // Compute arguments
1983 int arg_length = cse.compute_for_parameters(is_static != 0, in);
1984 assert(arg_length<=MAXARGSIZE, "too many locals");
1985
1986 // Pop arguments
1987 for (int i = arg_length - 1; i >= 0; i--) ppop1(in[i]);// Do args in reverse order.
1988
1989 // Report results
1990 if (_report_result_for_send == true) {
1991 fill_stackmap_for_opcodes(_itr_send, vars(), stack(), _stack_top);
1992 _report_result_for_send = false;
1993 }
1994
1995 // Push return address
1996 ppush(out);
1997 }
1998
1999 void GenerateOopMap::do_withfield(int idx, int bci) {
2000 // Dig up signature for field in constant pool
2001 ConstantPool* cp = method()->constants();
2002 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
2003 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
2004 Symbol* signature = cp->symbol_at(signatureIdx);
2005
2006 // Parse signature (especially simple for fields)
2007 assert(signature->utf8_length() > 0,
2008 "field signatures cannot have zero length");
2009 // The signature is UFT8 encoded, but the first char is always ASCII for signatures.
2010 char sigch = (char) *(signature->base());
2011 CellTypeState temp[4];
2012 CellTypeState *eff = sigchar_to_effect(sigch, bci, temp);
2013
2014 CellTypeState in[4];
2015 int i = copy_cts(in, eff);
2016 in[i++] = CellTypeState::ref;
2017 in[i] = CellTypeState::bottom;
2018 assert(i <= 3, "sanity check");
2019
2020 CellTypeState out[2];
2021 out[0] = CellTypeState::ref;
2022 out[1] = CellTypeState::bottom;
2023
2024 pp(in, out);
2025 }
2026
2027 // This is used to parse the signature for fields, since they are very simple...
2028 CellTypeState *GenerateOopMap::sigchar_to_effect(char sigch, int bci, CellTypeState *out) {
2029 // Object and array
2030 if (sigch=='L' || sigch=='[') {
2031 out[0] = CellTypeState::make_line_ref(bci);
2032 out[1] = CellTypeState::bottom;
2033 return out;
2034 }
2035 if (sigch == 'J' || sigch == 'D' ) return vvCTS; // Long and Double
2036 if (sigch == 'V' ) return epsilonCTS; // Void
2037 return vCTS; // Otherwise
2038 }
2039
2040 long GenerateOopMap::_total_byte_count = 0;
2041 elapsedTimer GenerateOopMap::_total_oopmap_time;
2042
2043 // This function assumes "bcs" is at a "ret" instruction and that the vars
2044 // state is valid for that instruction. Furthermore, the ret instruction
2045 // must be the last instruction in "bb" (we store information about the
2046 // "ret" in "bb").
2047 void GenerateOopMap::ret_jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int varNo, int *data) {
2048 CellTypeState ra = vars()[varNo];
2049 if (!ra.is_good_address()) {
2050 verify_error("ret returns from two jsr subroutines?");
2051 return;
2052 }
2053 int target = ra.get_info();
2054
2055 RetTableEntry* rtEnt = _rt.find_jsrs_for_target(target);
2056 int bci = bcs->bci();
2057 for (int i = 0; i < rtEnt->nof_jsrs(); i++) {
2058 int target_bci = rtEnt->jsrs(i);
2059 // Make sure a jrtRet does not set the changed bit for dead basicblock.
2060 BasicBlock* jsr_bb = get_basic_block_containing(target_bci - 1);
2061 debug_only(BasicBlock* target_bb = &jsr_bb[1];)
2062 assert(target_bb == get_basic_block_at(target_bci), "wrong calc. of successor basicblock");
2063 bool alive = jsr_bb->is_alive();
2064 if (TraceNewOopMapGeneration) {
2065 tty->print("pc = %d, ret -> %d alive: %s\n", bci, target_bci, alive ? "true" : "false");
2066 }
2067 if (alive) jmpFct(this, target_bci, data);
2068 }
2069 }
2070
2071 //
2072 // Debug method
2073 //
2074 char* GenerateOopMap::state_vec_to_string(CellTypeState* vec, int len) {
2075 #ifdef ASSERT
2076 int checklen = MAX3(_max_locals, _max_stack, _max_monitors) + 1;
2077 assert(len < checklen, "state_vec_buf overflow");
2078 #endif
2079 for (int i = 0; i < len; i++) _state_vec_buf[i] = vec[i].to_char();
2080 _state_vec_buf[len] = 0;
2081 return _state_vec_buf;
2082 }
2083
2084 void GenerateOopMap::print_time() {
2085 tty->print_cr ("Accumulated oopmap times:");
2086 tty->print_cr ("---------------------------");
2087 tty->print_cr (" Total : %3.3f sec.", GenerateOopMap::_total_oopmap_time.seconds());
2088 tty->print_cr (" (%3.0f bytecodes per sec) ",
2089 GenerateOopMap::_total_byte_count / GenerateOopMap::_total_oopmap_time.seconds());
2090 }
2091
2092 //
2093 // ============ Main Entry Point ===========
2094 //
2095 GenerateOopMap::GenerateOopMap(const methodHandle& method) {
2096 // We have to initialize all variables here, that can be queried directly
2097 _method = method;
2098 _max_locals=0;
2099 _init_vars = NULL;
2100
2101 #ifndef PRODUCT
2102 // If we are doing a detailed trace, include the regular trace information.
2103 if (TraceNewOopMapGenerationDetailed) {
2104 TraceNewOopMapGeneration = true;
2105 }
2106 #endif
2107 }
2108
2109 void GenerateOopMap::compute_map(TRAPS) {
2110 #ifndef PRODUCT
2111 if (TimeOopMap2) {
2112 method()->print_short_name(tty);
2113 tty->print(" ");
2114 }
2115 if (TimeOopMap) {
2116 _total_byte_count += method()->code_size();
2117 }
2118 #endif
2119 TraceTime t_single("oopmap time", TimeOopMap2);
2120 TraceTime t_all(NULL, &_total_oopmap_time, TimeOopMap);
2121
2122 // Initialize values
2123 _got_error = false;
2124 _conflict = false;
2125 _max_locals = method()->max_locals();
2126 _max_stack = method()->max_stack();
2127 _has_exceptions = (method()->has_exception_handler());
2128 _nof_refval_conflicts = 0;
2129 _init_vars = new GrowableArray<intptr_t>(5); // There are seldom more than 5 init_vars
2130 _report_result = false;
2131 _report_result_for_send = false;
2132 _new_var_map = NULL;
2133 _ret_adr_tos = new GrowableArray<intptr_t>(5); // 5 seems like a good number;
2134 _did_rewriting = false;
2135 _did_relocation = false;
2136
2137 if (TraceNewOopMapGeneration) {
2138 tty->print("Method name: %s\n", method()->name()->as_C_string());
2139 if (Verbose) {
2140 _method->print_codes();
2141 tty->print_cr("Exception table:");
2142 ExceptionTable excps(method());
2143 for(int i = 0; i < excps.length(); i ++) {
2144 tty->print_cr("[%d - %d] -> %d",
2145 excps.start_pc(i), excps.end_pc(i), excps.handler_pc(i));
2146 }
2147 }
2148 }
2149
2150 // if no code - do nothing
2151 // compiler needs info
2152 if (method()->code_size() == 0 || _max_locals + method()->max_stack() == 0) {
2153 fill_stackmap_prolog(0);
2154 fill_stackmap_epilog();
2155 return;
2156 }
2157 // Step 1: Compute all jump targets and their return value
2158 if (!_got_error)
2159 _rt.compute_ret_table(_method);
2160
2161 // Step 2: Find all basic blocks and count GC points
2162 if (!_got_error)
2163 mark_bbheaders_and_count_gc_points();
2164
2165 // Step 3: Calculate stack maps
2166 if (!_got_error)
2167 do_interpretation();
2168
2169 // Step 4:Return results
2170 if (!_got_error && report_results())
2171 report_result();
2172
2173 if (_got_error) {
2174 THROW_HANDLE(_exception);
2175 }
2176 }
2177
2178 // Error handling methods
2179 // These methods create an exception for the current thread which is thrown
2180 // at the bottom of the call stack, when it returns to compute_map(). The
2181 // _got_error flag controls execution. NOT TODO: The VM exception propagation
2182 // mechanism using TRAPS/CHECKs could be used here instead but it would need
2183 // to be added as a parameter to every function and checked for every call.
2184 // The tons of extra code it would generate didn't seem worth the change.
2185 //
2186 void GenerateOopMap::error_work(const char *format, va_list ap) {
2187 _got_error = true;
2188 char msg_buffer[512];
2189 vsnprintf(msg_buffer, sizeof(msg_buffer), format, ap);
2190 // Append method name
2191 char msg_buffer2[512];
2192 jio_snprintf(msg_buffer2, sizeof(msg_buffer2), "%s in method %s", msg_buffer, method()->name()->as_C_string());
2193 if (Thread::current()->can_call_java()) {
2194 _exception = Exceptions::new_exception(Thread::current(),
2195 vmSymbols::java_lang_LinkageError(), msg_buffer2);
2196 } else {
2197 // We cannot instantiate an exception object from a compiler thread.
2198 // Exit the VM with a useful error message.
2199 fatal("%s", msg_buffer2);
2200 }
2201 }
2202
2203 void GenerateOopMap::report_error(const char *format, ...) {
2204 va_list ap;
2205 va_start(ap, format);
2206 error_work(format, ap);
2207 }
2208
2209 void GenerateOopMap::verify_error(const char *format, ...) {
2210 // We do not distinguish between different types of errors for verification
2211 // errors. Let the verifier give a better message.
2212 report_error("Illegal class file encountered. Try running with -Xverify:all");
2213 }
2214
2215 //
2216 // Report result opcodes
2217 //
2218 void GenerateOopMap::report_result() {
2219
2220 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass");
2221
2222 // We now want to report the result of the parse
2223 _report_result = true;
2224
2225 // Prolog code
2226 fill_stackmap_prolog(_gc_points);
2227
2228 // Mark everything changed, then do one interpretation pass.
2229 for (int i = 0; i<_bb_count; i++) {
2230 if (_basic_blocks[i].is_reachable()) {
2231 _basic_blocks[i].set_changed(true);
2232 interp_bb(&_basic_blocks[i]);
2233 }
2234 }
2235
2236 // Note: Since we are skipping dead-code when we are reporting results, then
2237 // the no. of encountered gc-points might be fewer than the previously number
2238 // we have counted. (dead-code is a pain - it should be removed before we get here)
2239 fill_stackmap_epilog();
2240
2241 // Report initvars
2242 fill_init_vars(_init_vars);
2243
2244 _report_result = false;
2245 }
2246
2247 void GenerateOopMap::result_for_basicblock(int bci) {
2248 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass for basicblock");
2249
2250 // We now want to report the result of the parse
2251 _report_result = true;
2252
2253 // Find basicblock and report results
2254 BasicBlock* bb = get_basic_block_containing(bci);
2255 guarantee(bb != NULL, "no basic block for bci");
2256 assert(bb->is_reachable(), "getting result from unreachable basicblock");
2257 bb->set_changed(true);
2258 interp_bb(bb);
2259 }
2260
2261 //
2262 // Conflict handling code
2263 //
2264
2265 void GenerateOopMap::record_refval_conflict(int varNo) {
2266 assert(varNo>=0 && varNo< _max_locals, "index out of range");
2267
2268 if (TraceOopMapRewrites) {
2269 tty->print("### Conflict detected (local no: %d)\n", varNo);
2270 }
2271
2272 if (!_new_var_map) {
2273 _new_var_map = NEW_RESOURCE_ARRAY(int, _max_locals);
2274 for (int k = 0; k < _max_locals; k++) _new_var_map[k] = k;
2275 }
2276
2277 if ( _new_var_map[varNo] == varNo) {
2278 // Check if max. number of locals has been reached
2279 if (_max_locals + _nof_refval_conflicts >= MAX_LOCAL_VARS) {
2280 report_error("Rewriting exceeded local variable limit");
2281 return;
2282 }
2283 _new_var_map[varNo] = _max_locals + _nof_refval_conflicts;
2284 _nof_refval_conflicts++;
2285 }
2286 }
2287
2288 void GenerateOopMap::rewrite_refval_conflicts()
2289 {
2290 // We can get here two ways: Either a rewrite conflict was detected, or
2291 // an uninitialize reference was detected. In the second case, we do not
2292 // do any rewriting, we just want to recompute the reference set with the
2293 // new information
2294
2295 int nof_conflicts = 0; // Used for debugging only
2296
2297 if ( _nof_refval_conflicts == 0 )
2298 return;
2299
2300 // Check if rewrites are allowed in this parse.
2301 if (!allow_rewrites() && !IgnoreRewrites) {
2302 fatal("Rewriting method not allowed at this stage");
2303 }
2304
2305
2306 // This following flag is to tempoary supress rewrites. The locals that might conflict will
2307 // all be set to contain values. This is UNSAFE - however, until the rewriting has been completely
2308 // tested it is nice to have.
2309 if (IgnoreRewrites) {
2310 if (Verbose) {
2311 tty->print("rewrites suppressed for local no. ");
2312 for (int l = 0; l < _max_locals; l++) {
2313 if (_new_var_map[l] != l) {
2314 tty->print("%d ", l);
2315 vars()[l] = CellTypeState::value;
2316 }
2317 }
2318 tty->cr();
2319 }
2320
2321 // That was that...
2322 _new_var_map = NULL;
2323 _nof_refval_conflicts = 0;
2324 _conflict = false;
2325
2326 return;
2327 }
2328
2329 // Tracing flag
2330 _did_rewriting = true;
2331
2332 if (TraceOopMapRewrites) {
2333 tty->print_cr("ref/value conflict for method %s - bytecodes are getting rewritten", method()->name()->as_C_string());
2334 method()->print();
2335 method()->print_codes();
2336 }
2337
2338 assert(_new_var_map!=NULL, "nothing to rewrite");
2339 assert(_conflict==true, "We should not be here");
2340
2341 compute_ret_adr_at_TOS();
2342 if (!_got_error) {
2343 for (int k = 0; k < _max_locals && !_got_error; k++) {
2344 if (_new_var_map[k] != k) {
2345 if (TraceOopMapRewrites) {
2346 tty->print_cr("Rewriting: %d -> %d", k, _new_var_map[k]);
2347 }
2348 rewrite_refval_conflict(k, _new_var_map[k]);
2349 if (_got_error) return;
2350 nof_conflicts++;
2351 }
2352 }
2353 }
2354
2355 assert(nof_conflicts == _nof_refval_conflicts, "sanity check");
2356
2357 // Adjust the number of locals
2358 method()->set_max_locals(_max_locals+_nof_refval_conflicts);
2359 _max_locals += _nof_refval_conflicts;
2360
2361 // That was that...
2362 _new_var_map = NULL;
2363 _nof_refval_conflicts = 0;
2364 }
2365
2366 void GenerateOopMap::rewrite_refval_conflict(int from, int to) {
2367 bool startOver;
2368 do {
2369 // Make sure that the BytecodeStream is constructed in the loop, since
2370 // during rewriting a new method oop is going to be used, and the next time
2371 // around we want to use that.
2372 BytecodeStream bcs(_method);
2373 startOver = false;
2374
2375 while( !startOver && !_got_error &&
2376 // test bcs in case method changed and it became invalid
2377 bcs.next() >=0) {
2378 startOver = rewrite_refval_conflict_inst(&bcs, from, to);
2379 }
2380 } while (startOver && !_got_error);
2381 }
2382
2383 /* If the current instruction is one that uses local variable "from"
2384 in a ref way, change it to use "to". There's a subtle reason why we
2385 renumber the ref uses and not the non-ref uses: non-ref uses may be
2386 2 slots wide (double, long) which would necessitate keeping track of
2387 whether we should add one or two variables to the method. If the change
2388 affected the width of some instruction, returns "TRUE"; otherwise, returns "FALSE".
2389 Another reason for moving ref's value is for solving (addr, ref) conflicts, which
2390 both uses aload/astore methods.
2391 */
2392 bool GenerateOopMap::rewrite_refval_conflict_inst(BytecodeStream *itr, int from, int to) {
2393 Bytecodes::Code bc = itr->code();
2394 int index;
2395 int bci = itr->bci();
2396
2397 if (is_aload(itr, &index) && index == from) {
2398 if (TraceOopMapRewrites) {
2399 tty->print_cr("Rewriting aload at bci: %d", bci);
2400 }
2401 return rewrite_load_or_store(itr, Bytecodes::_aload, Bytecodes::_aload_0, to);
2402 }
2403
2404 if (is_astore(itr, &index) && index == from) {
2405 if (!stack_top_holds_ret_addr(bci)) {
2406 if (TraceOopMapRewrites) {
2407 tty->print_cr("Rewriting astore at bci: %d", bci);
2408 }
2409 return rewrite_load_or_store(itr, Bytecodes::_astore, Bytecodes::_astore_0, to);
2410 } else {
2411 if (TraceOopMapRewrites) {
2412 tty->print_cr("Supress rewriting of astore at bci: %d", bci);
2413 }
2414 }
2415 }
2416
2417 return false;
2418 }
2419
2420 // The argument to this method is:
2421 // bc : Current bytecode
2422 // bcN : either _aload or _astore
2423 // bc0 : either _aload_0 or _astore_0
2424 bool GenerateOopMap::rewrite_load_or_store(BytecodeStream *bcs, Bytecodes::Code bcN, Bytecodes::Code bc0, unsigned int varNo) {
2425 assert(bcN == Bytecodes::_astore || bcN == Bytecodes::_aload, "wrong argument (bcN)");
2426 assert(bc0 == Bytecodes::_astore_0 || bc0 == Bytecodes::_aload_0, "wrong argument (bc0)");
2427 int ilen = Bytecodes::length_at(_method(), bcs->bcp());
2428 int newIlen;
2429
2430 if (ilen == 4) {
2431 // Original instruction was wide; keep it wide for simplicity
2432 newIlen = 4;
2433 } else if (varNo < 4)
2434 newIlen = 1;
2435 else if (varNo >= 256)
2436 newIlen = 4;
2437 else
2438 newIlen = 2;
2439
2440 // If we need to relocate in order to patch the byte, we
2441 // do the patching in a temp. buffer, that is passed to the reloc.
2442 // The patching of the bytecode stream is then done by the Relocator.
2443 // This is neccesary, since relocating the instruction at a certain bci, might
2444 // also relocate that instruction, e.g., if a _goto before it gets widen to a _goto_w.
2445 // Hence, we do not know which bci to patch after relocation.
2446
2447 assert(newIlen <= 4, "sanity check");
2448 u_char inst_buffer[4]; // Max. instruction size is 4.
2449 address bcp;
2450
2451 if (newIlen != ilen) {
2452 // Relocation needed do patching in temp. buffer
2453 bcp = (address)inst_buffer;
2454 } else {
2455 bcp = _method->bcp_from(bcs->bci());
2456 }
2457
2458 // Patch either directly in Method* or in temp. buffer
2459 if (newIlen == 1) {
2460 assert(varNo < 4, "varNo too large");
2461 *bcp = bc0 + varNo;
2462 } else if (newIlen == 2) {
2463 assert(varNo < 256, "2-byte index needed!");
2464 *(bcp + 0) = bcN;
2465 *(bcp + 1) = varNo;
2466 } else {
2467 assert(newIlen == 4, "Wrong instruction length");
2468 *(bcp + 0) = Bytecodes::_wide;
2469 *(bcp + 1) = bcN;
2470 Bytes::put_Java_u2(bcp+2, varNo);
2471 }
2472
2473 if (newIlen != ilen) {
2474 expand_current_instr(bcs->bci(), ilen, newIlen, inst_buffer);
2475 }
2476
2477
2478 return (newIlen != ilen);
2479 }
2480
2481 class RelocCallback : public RelocatorListener {
2482 private:
2483 GenerateOopMap* _gom;
2484 public:
2485 RelocCallback(GenerateOopMap* gom) { _gom = gom; };
2486
2487 // Callback method
2488 virtual void relocated(int bci, int delta, int new_code_length) {
2489 _gom->update_basic_blocks (bci, delta, new_code_length);
2490 _gom->update_ret_adr_at_TOS(bci, delta);
2491 _gom->_rt.update_ret_table (bci, delta);
2492 }
2493 };
2494
2495 // Returns true if expanding was succesful. Otherwise, reports an error and
2496 // returns false.
2497 void GenerateOopMap::expand_current_instr(int bci, int ilen, int newIlen, u_char inst_buffer[]) {
2498 Thread *THREAD = Thread::current(); // Could really have TRAPS argument.
2499 RelocCallback rcb(this);
2500 Relocator rc(_method, &rcb);
2501 methodHandle m= rc.insert_space_at(bci, newIlen, inst_buffer, THREAD);
2502 if (m.is_null() || HAS_PENDING_EXCEPTION) {
2503 report_error("could not rewrite method - exception occurred or bytecode buffer overflow");
2504 return;
2505 }
2506
2507 // Relocator returns a new method oop.
2508 _did_relocation = true;
2509 _method = m;
2510 }
2511
2512
2513 bool GenerateOopMap::is_astore(BytecodeStream *itr, int *index) {
2514 Bytecodes::Code bc = itr->code();
2515 switch(bc) {
2516 case Bytecodes::_astore_0:
2517 case Bytecodes::_astore_1:
2518 case Bytecodes::_astore_2:
2519 case Bytecodes::_astore_3:
2520 *index = bc - Bytecodes::_astore_0;
2521 return true;
2522 case Bytecodes::_astore:
2523 *index = itr->get_index();
2524 return true;
2525 default:
2526 return false;
2527 }
2528 }
2529
2530 bool GenerateOopMap::is_aload(BytecodeStream *itr, int *index) {
2531 Bytecodes::Code bc = itr->code();
2532 switch(bc) {
2533 case Bytecodes::_aload_0:
2534 case Bytecodes::_aload_1:
2535 case Bytecodes::_aload_2:
2536 case Bytecodes::_aload_3:
2537 *index = bc - Bytecodes::_aload_0;
2538 return true;
2539
2540 case Bytecodes::_aload:
2541 *index = itr->get_index();
2542 return true;
2543
2544 default:
2545 return false;
2546 }
2547 }
2548
2549
2550 // Return true iff the top of the operand stack holds a return address at
2551 // the current instruction
2552 bool GenerateOopMap::stack_top_holds_ret_addr(int bci) {
2553 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2554 if (_ret_adr_tos->at(i) == bci)
2555 return true;
2556 }
2557
2558 return false;
2559 }
2560
2561 void GenerateOopMap::compute_ret_adr_at_TOS() {
2562 assert(_ret_adr_tos != NULL, "must be initialized");
2563 _ret_adr_tos->clear();
2564
2565 for (int i = 0; i < bb_count(); i++) {
2566 BasicBlock* bb = &_basic_blocks[i];
2567
2568 // Make sure to only check basicblocks that are reachable
2569 if (bb->is_reachable()) {
2570
2571 // For each Basic block we check all instructions
2572 BytecodeStream bcs(_method);
2573 bcs.set_interval(bb->_bci, next_bb_start_pc(bb));
2574
2575 restore_state(bb);
2576
2577 while (bcs.next()>=0 && !_got_error) {
2578 // TDT: should this be is_good_address() ?
2579 if (_stack_top > 0 && stack()[_stack_top-1].is_address()) {
2580 _ret_adr_tos->append(bcs.bci());
2581 if (TraceNewOopMapGeneration) {
2582 tty->print_cr("Ret_adr TOS at bci: %d", bcs.bci());
2583 }
2584 }
2585 interp1(&bcs);
2586 }
2587 }
2588 }
2589 }
2590
2591 void GenerateOopMap::update_ret_adr_at_TOS(int bci, int delta) {
2592 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2593 int v = _ret_adr_tos->at(i);
2594 if (v > bci) _ret_adr_tos->at_put(i, v + delta);
2595 }
2596 }
2597
2598 // ===================================================================
2599
2600 #ifndef PRODUCT
2601 int ResolveOopMapConflicts::_nof_invocations = 0;
2602 int ResolveOopMapConflicts::_nof_rewrites = 0;
2603 int ResolveOopMapConflicts::_nof_relocations = 0;
2604 #endif
2605
2606 methodHandle ResolveOopMapConflicts::do_potential_rewrite(TRAPS) {
2607 compute_map(CHECK_(methodHandle()));
2608
2609 #ifndef PRODUCT
2610 // Tracking and statistics
2611 if (PrintRewrites) {
2612 _nof_invocations++;
2613 if (did_rewriting()) {
2614 _nof_rewrites++;
2615 if (did_relocation()) _nof_relocations++;
2616 tty->print("Method was rewritten %s: ", (did_relocation()) ? "and relocated" : "");
2617 method()->print_value(); tty->cr();
2618 tty->print_cr("Cand.: %d rewrts: %d (%d%%) reloc.: %d (%d%%)",
2619 _nof_invocations,
2620 _nof_rewrites, (_nof_rewrites * 100) / _nof_invocations,
2621 _nof_relocations, (_nof_relocations * 100) / _nof_invocations);
2622 }
2623 }
2624 #endif
2625 return methodHandle(THREAD, method());
2626 }