1 /*
2 * Copyright (c) 1997, 2017, 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
1596
1597 case Bytecodes::_getstatic: do_field(true, true, itr->get_index_u2_cpcache(), itr->bci()); break;
1598 case Bytecodes::_putstatic: do_field(false, true, itr->get_index_u2_cpcache(), itr->bci()); break;
1599 case Bytecodes::_getfield: do_field(true, false, itr->get_index_u2_cpcache(), itr->bci()); break;
1600 case Bytecodes::_putfield: do_field(false, false, itr->get_index_u2_cpcache(), itr->bci()); break;
1601
1602 case Bytecodes::_invokeinterface:
1603 case Bytecodes::_invokevirtual:
1604 case Bytecodes::_invokespecial: do_method(false, itr->get_index_u2_cpcache(), itr->bci()); break;
1605 case Bytecodes::_invokestatic: do_method(true , itr->get_index_u2_cpcache(), itr->bci()); break;
1606 case Bytecodes::_invokedynamic: do_method(true , itr->get_index_u4(), itr->bci()); break;
1607 case Bytecodes::_newarray:
1608 case Bytecodes::_anewarray: pp_new_ref(vCTS, itr->bci()); break;
1609 case Bytecodes::_checkcast: do_checkcast(); break;
1610 case Bytecodes::_arraylength:
1611 case Bytecodes::_instanceof: pp(rCTS, vCTS); break;
1612 case Bytecodes::_monitorenter: do_monitorenter(itr->bci()); break;
1613 case Bytecodes::_monitorexit: do_monitorexit(itr->bci()); break;
1614
1615 case Bytecodes::_athrow: // handled by do_exception_edge() BUT ...
1616 // vlh(apple): do_exception_edge() does not get
1617 // called if method has no exception handlers
1618 if ((!_has_exceptions) && (_monitor_top > 0)) {
1619 _monitor_safe = false;
1620 }
1621 break;
1622
1623 case Bytecodes::_areturn: do_return_monitor_check();
1624 ppop1(refCTS);
1625 break;
1626
1627 case Bytecodes::_ifnull:
1628 case Bytecodes::_ifnonnull: ppop1(refCTS); break;
1629 case Bytecodes::_multianewarray: do_multianewarray(*(itr->bcp()+3), itr->bci()); break;
1630
1631 case Bytecodes::_wide: fatal("Iterator should skip this bytecode"); break;
1632 case Bytecodes::_ret: break;
1633
1634 // Java opcodes
1635 case Bytecodes::_lookupswitch: ppop1(valCTS); break;
1636
1637 default:
1638 tty->print("unexpected opcode: %d\n", itr->code());
1639 ShouldNotReachHere();
1640 break;
1641 }
1642 }
1643
1644 void GenerateOopMap::check_type(CellTypeState expected, CellTypeState actual) {
1645 if (!expected.equal_kind(actual)) {
1646 verify_error("wrong type on stack (found: %c expected: %c)", actual.to_char(), expected.to_char());
1647 }
1648 }
1649
1650 void GenerateOopMap::ppstore(CellTypeState *in, int loc_no) {
1651 while(!(*in).is_bottom()) {
1652 CellTypeState expected =*in++;
1653 CellTypeState actual = pop();
1654 check_type(expected, actual);
1655 assert(loc_no >= 0, "sanity check");
1656 set_var(loc_no++, actual);
1657 }
1658 }
1659
1660 void GenerateOopMap::ppload(CellTypeState *out, int loc_no) {
1661 while(!(*out).is_bottom()) {
1662 CellTypeState out1 = *out++;
1663 CellTypeState vcts = get_var(loc_no);
1664 assert(out1.can_be_reference() || out1.can_be_value(),
1665 "can only load refs. and values.");
1666 if (out1.is_reference()) {
1667 assert(loc_no>=0, "sanity check");
1668 if (!vcts.is_reference()) {
1669 // We were asked to push a reference, but the type of the
1670 // variable can be something else
1671 _conflict = true;
1672 if (vcts.can_be_uninit()) {
1673 // It is a ref-uninit conflict (at least). If there are other
1674 // problems, we'll get them in the next round
1675 add_to_ref_init_set(loc_no);
1676 vcts = out1;
1677 } else {
1678 // It wasn't a ref-uninit conflict. So must be a
1679 // ref-val or ref-pc conflict. Split the variable.
1680 record_refval_conflict(loc_no);
1681 vcts = out1;
1682 }
1683 push(out1); // recover...
1684 } else {
1685 push(vcts); // preserve reference.
1686 }
1687 // Otherwise it is a conflict, but one that verification would
1688 // have caught if illegal. In particular, it can't be a topCTS
1689 // resulting from mergeing two difference pcCTS's since the verifier
1690 // would have rejected any use of such a merge.
1691 } else {
1692 push(out1); // handle val/init conflict
1693 }
1694 loc_no++;
1695 }
1696 }
1697
1698 void GenerateOopMap::ppdupswap(int poplen, const char *out) {
1699 CellTypeState actual[5];
1700 assert(poplen < 5, "this must be less than length of actual vector");
1701
1702 // Pop all arguments.
1703 for (int i = 0; i < poplen; i++) {
1704 actual[i] = pop();
1705 }
1706 // Field _state is uninitialized when calling push.
1707 for (int i = poplen; i < 5; i++) {
1708 actual[i] = CellTypeState::uninit;
1709 }
1710
1711 // put them back
1712 char push_ch = *out++;
1713 while (push_ch != '\0') {
1714 int idx = push_ch - '1';
1715 assert(idx >= 0 && idx < poplen, "wrong arguments");
1716 push(actual[idx]);
1717 push_ch = *out++;
1718 }
1719 }
1720
1721 void GenerateOopMap::ppop1(CellTypeState out) {
1722 CellTypeState actual = pop();
1723 check_type(out, actual);
1724 }
1725
1726 void GenerateOopMap::ppop(CellTypeState *out) {
1727 while (!(*out).is_bottom()) {
1728 ppop1(*out++);
1729 }
1730 }
1731
1732 void GenerateOopMap::ppush1(CellTypeState in) {
1733 assert(in.is_reference() || in.is_value(), "sanity check");
1734 push(in);
1735 }
1736
1737 void GenerateOopMap::ppush(CellTypeState *in) {
1738 while (!(*in).is_bottom()) {
1739 ppush1(*in++);
1740 }
1741 }
1742
1743 void GenerateOopMap::pp(CellTypeState *in, CellTypeState *out) {
1744 ppop(in);
1745 ppush(out);
1746 }
1747
1748 void GenerateOopMap::pp_new_ref(CellTypeState *in, int bci) {
1749 ppop(in);
1750 ppush1(CellTypeState::make_line_ref(bci));
1751 }
1752
1753 void GenerateOopMap::ppop_any(int poplen) {
1754 if (_stack_top >= poplen) {
1755 _stack_top -= poplen;
1756 } else {
1757 verify_error("stack underflow");
1758 }
1759 }
1760
1761 // Replace all occurences of the state 'match' with the state 'replace'
1762 // in our current state vector.
1763 void GenerateOopMap::replace_all_CTS_matches(CellTypeState match,
1764 CellTypeState replace) {
1765 int i;
1766 int len = _max_locals + _stack_top;
1767 bool change = false;
1768
1769 for (i = len - 1; i >= 0; i--) {
1770 if (match.equal(_state[i])) {
1771 _state[i] = replace;
1772 }
1773 }
1774
1775 if (_monitor_top > 0) {
1776 int base = _max_locals + _max_stack;
1777 len = base + _monitor_top;
1778 for (i = len - 1; i >= base; i--) {
1779 if (match.equal(_state[i])) {
1780 _state[i] = replace;
1781 }
1782 }
1783 }
1784 }
1785
1786 void GenerateOopMap::do_checkcast() {
1787 CellTypeState actual = pop();
1788 check_type(refCTS, actual);
1789 push(actual);
1790 }
1791
1792 void GenerateOopMap::do_monitorenter(int bci) {
1793 CellTypeState actual = pop();
1794 if (_monitor_top == bad_monitors) {
1795 return;
1796 }
1797
1798 // Bail out when we get repeated locks on an identical monitor. This case
1799 // isn't too hard to handle and can be made to work if supporting nested
1800 // redundant synchronized statements becomes a priority.
1801 //
1802 // See also "Note" in do_monitorexit(), below.
1803 if (actual.is_lock_reference()) {
1804 _monitor_top = bad_monitors;
1805 _monitor_safe = false;
1806
1807 if (log_is_enabled(Info, monitormismatch)) {
1808 report_monitor_mismatch("nested redundant lock -- bailout...");
1809 }
1810 return;
1811 }
1812
1813 CellTypeState lock = CellTypeState::make_lock_ref(bci);
1814 check_type(refCTS, actual);
1815 if (!actual.is_info_top()) {
1816 replace_all_CTS_matches(actual, lock);
1817 monitor_push(lock);
1818 }
1819 }
1820
1821 void GenerateOopMap::do_monitorexit(int bci) {
1822 CellTypeState actual = pop();
1823 if (_monitor_top == bad_monitors) {
1824 return;
1825 }
1826 check_type(refCTS, actual);
1827 CellTypeState expected = monitor_pop();
1828 if (!actual.is_lock_reference() || !expected.equal(actual)) {
1829 // The monitor we are exiting is not verifiably the one
1830 // on the top of our monitor stack. This causes a monitor
1831 // mismatch.
1832 _monitor_top = bad_monitors;
1833 _monitor_safe = false;
1834
1835 // We need to mark this basic block as changed so that
1836 // this monitorexit will be visited again. We need to
1837 // do this to ensure that we have accounted for the
1838 // possibility that this bytecode will throw an
1839 // exception.
1840 BasicBlock* bb = get_basic_block_containing(bci);
1841 guarantee(bb != NULL, "no basic block for bci");
1842 bb->set_changed(true);
1843 bb->_monitor_top = bad_monitors;
1844
1845 if (log_is_enabled(Info, monitormismatch)) {
1846 report_monitor_mismatch("improper monitor pair");
1847 }
1848 } else {
1849 // This code is a fix for the case where we have repeated
1850 // locking of the same object in straightline code. We clear
1851 // out the lock when it is popped from the monitor stack
1852 // and replace it with an unobtrusive reference value that can
1853 // be locked again.
1854 //
1855 // Note: when generateOopMap is fixed to properly handle repeated,
1856 // nested, redundant locks on the same object, then this
1857 // fix will need to be removed at that time.
1858 replace_all_CTS_matches(actual, CellTypeState::make_line_ref(bci));
1859 }
1860 }
1861
1862 void GenerateOopMap::do_return_monitor_check() {
1863 if (_monitor_top > 0) {
1864 // The monitor stack must be empty when we leave the method
1865 // for the monitors to be properly matched.
1866 _monitor_safe = false;
1867
1868 // Since there are no successors to the *return bytecode, it
1869 // isn't necessary to set _monitor_top to bad_monitors.
1870
1871 if (log_is_enabled(Info, monitormismatch)) {
1872 report_monitor_mismatch("non-empty monitor stack at return");
1873 }
1874 }
1875 }
1876
1877 void GenerateOopMap::do_jsr(int targ_bci) {
1878 push(CellTypeState::make_addr(targ_bci));
1879 }
1880
1881
1882
1883 void GenerateOopMap::do_ldc(int bci) {
1884 Bytecode_loadconstant ldc(method(), bci);
1885 ConstantPool* cp = method()->constants();
1886 constantTag tag = cp->tag_at(ldc.pool_index()); // idx is index in resolved_references
1887 BasicType bt = ldc.result_type();
1888 #ifdef ASSERT
1889 BasicType tag_bt = tag.is_dynamic_constant() ? bt : tag.basic_type();
1890 assert(bt == tag_bt, "same result");
1891 #endif
1892 CellTypeState cts;
1893 if (is_reference_type(bt)) { // could be T_ARRAY with condy
1894 assert(!tag.is_string_index() && !tag.is_klass_index() && !tag.is_value_type_index(), "Unexpected index tag");
1895 cts = CellTypeState::make_line_ref(bci);
1896 } else {
1897 cts = valCTS;
1898 }
1899 ppush1(cts);
1900 }
1901
1902 void GenerateOopMap::do_multianewarray(int dims, int bci) {
1903 assert(dims >= 1, "sanity check");
1904 for(int i = dims -1; i >=0; i--) {
1905 ppop1(valCTS);
1906 }
1907 ppush1(CellTypeState::make_line_ref(bci));
1908 }
1909
1910 void GenerateOopMap::do_astore(int idx) {
1911 CellTypeState r_or_p = pop();
1912 if (!r_or_p.is_address() && !r_or_p.is_reference()) {
1913 // We actually expected ref or pc, but we only report that we expected a ref. It does not
1914 // really matter (at least for now)
1915 verify_error("wrong type on stack (found: %c, expected: {pr})", r_or_p.to_char());
1916 return;
1917 }
1918 set_var(idx, r_or_p);
1919 }
1920
1921 // Copies bottom/zero terminated CTS string from "src" into "dst".
1922 // Does NOT terminate with a bottom. Returns the number of cells copied.
1923 int GenerateOopMap::copy_cts(CellTypeState *dst, CellTypeState *src) {
1924 int idx = 0;
1925 while (!src[idx].is_bottom()) {
1926 dst[idx] = src[idx];
1927 idx++;
1928 }
1929 return idx;
1930 }
1931
1932 void GenerateOopMap::do_field(int is_get, int is_static, int idx, int bci) {
1933 // Dig up signature for field in constant pool
1934 ConstantPool* cp = method()->constants();
1935 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
1936 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1937 Symbol* signature = cp->symbol_at(signatureIdx);
1938
1939 // Parse signature (espcially simple for fields)
1940 assert(signature->utf8_length() > 0, "field signatures cannot have zero length");
1941 // The signature is UFT8 encoded, but the first char is always ASCII for signatures.
1942 char sigch = (char)*(signature->base());
1943 CellTypeState temp[4];
1944 CellTypeState *eff = sigchar_to_effect(sigch, bci, temp);
1945
1946 CellTypeState in[4];
1947 CellTypeState *out;
1948 int i = 0;
1949
1950 if (is_get) {
1951 out = eff;
1952 } else {
1953 out = epsilonCTS;
1954 i = copy_cts(in, eff);
1955 }
1956 if (!is_static) {
1957 in[i++] = CellTypeState::ref;
1958 }
1959 in[i] = CellTypeState::bottom;
1960 assert(i<=3, "sanity check");
1961 pp(in, out);
1962 }
1963
1964 void GenerateOopMap::do_method(int is_static, int idx, int bci) {
1965 // Dig up signature for field in constant pool
1966 ConstantPool* cp = _method->constants();
1967 Symbol* signature = cp->signature_ref_at(idx);
1968
1969 // Parse method signature
1970 CellTypeState out[4];
1971 CellTypeState in[MAXARGSIZE+1]; // Includes result
1972 ComputeCallStack cse(signature);
1973
1974 // Compute return type
1975 int res_length= cse.compute_for_returntype(out);
1976
1977 // Temporary hack.
1978 if (out[0].equal(CellTypeState::ref) && out[1].equal(CellTypeState::bottom)) {
1979 out[0] = CellTypeState::make_line_ref(bci);
1980 }
1981
1982 assert(res_length<=4, "max value should be vv");
1983
1984 // Compute arguments
1985 int arg_length = cse.compute_for_parameters(is_static != 0, in);
1986 assert(arg_length<=MAXARGSIZE, "too many locals");
1987
1988 // Pop arguments
1989 for (int i = arg_length - 1; i >= 0; i--) ppop1(in[i]);// Do args in reverse order.
1990
1991 // Report results
1992 if (_report_result_for_send == true) {
1993 fill_stackmap_for_opcodes(_itr_send, vars(), stack(), _stack_top);
1994 _report_result_for_send = false;
1995 }
1996
1997 // Push return address
1998 ppush(out);
1999 }
2000
2001 void GenerateOopMap::do_withfield(int idx, int bci) {
2002 // Dig up signature for field in constant pool
2003 ConstantPool* cp = method()->constants();
2004 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
2005 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
2006 Symbol* signature = cp->symbol_at(signatureIdx);
2007
2008 // Parse signature (especially simple for fields)
2009 assert(signature->utf8_length() > 0,
2010 "field signatures cannot have zero length");
2011 // The signature is UFT8 encoded, but the first char is always ASCII for signatures.
2012 char sigch = (char) *(signature->base());
2013 CellTypeState temp[4];
2014 CellTypeState *eff = sigchar_to_effect(sigch, bci, temp);
2015
2016 CellTypeState in[4];
2017 int i = copy_cts(in, eff);
2018 in[i++] = CellTypeState::ref;
2019 in[i] = CellTypeState::bottom;
2020 assert(i <= 3, "sanity check");
2021
2022 CellTypeState out[2];
2023 out[0] = CellTypeState::ref;
2024 out[1] = CellTypeState::bottom;
2025
2026 pp(in, out);
2027 }
2028
2029 // This is used to parse the signature for fields, since they are very simple...
2030 CellTypeState *GenerateOopMap::sigchar_to_effect(char sigch, int bci, CellTypeState *out) {
2031 // Object and array
2032 if (sigch=='L' || sigch=='[') {
2033 out[0] = CellTypeState::make_line_ref(bci);
2034 out[1] = CellTypeState::bottom;
2035 return out;
2036 }
2037 if (sigch == 'J' || sigch == 'D' ) return vvCTS; // Long and Double
2038 if (sigch == 'V' ) return epsilonCTS; // Void
2039 return vCTS; // Otherwise
2040 }
2041
2042 long GenerateOopMap::_total_byte_count = 0;
2043 elapsedTimer GenerateOopMap::_total_oopmap_time;
2044
2045 // This function assumes "bcs" is at a "ret" instruction and that the vars
2046 // state is valid for that instruction. Furthermore, the ret instruction
2047 // must be the last instruction in "bb" (we store information about the
2048 // "ret" in "bb").
2049 void GenerateOopMap::ret_jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int varNo, int *data) {
2050 CellTypeState ra = vars()[varNo];
2051 if (!ra.is_good_address()) {
2052 verify_error("ret returns from two jsr subroutines?");
2053 return;
2054 }
2055 int target = ra.get_info();
2056
2057 RetTableEntry* rtEnt = _rt.find_jsrs_for_target(target);
2058 int bci = bcs->bci();
2059 for (int i = 0; i < rtEnt->nof_jsrs(); i++) {
2060 int target_bci = rtEnt->jsrs(i);
2061 // Make sure a jrtRet does not set the changed bit for dead basicblock.
2062 BasicBlock* jsr_bb = get_basic_block_containing(target_bci - 1);
2063 debug_only(BasicBlock* target_bb = &jsr_bb[1];)
2064 assert(target_bb == get_basic_block_at(target_bci), "wrong calc. of successor basicblock");
2065 bool alive = jsr_bb->is_alive();
2066 if (TraceNewOopMapGeneration) {
2067 tty->print("pc = %d, ret -> %d alive: %s\n", bci, target_bci, alive ? "true" : "false");
2068 }
2069 if (alive) jmpFct(this, target_bci, data);
2070 }
2071 }
2072
2073 //
2074 // Debug method
2075 //
2076 char* GenerateOopMap::state_vec_to_string(CellTypeState* vec, int len) {
2077 #ifdef ASSERT
2078 int checklen = MAX3(_max_locals, _max_stack, _max_monitors) + 1;
2079 assert(len < checklen, "state_vec_buf overflow");
2080 #endif
2081 for (int i = 0; i < len; i++) _state_vec_buf[i] = vec[i].to_char();
2082 _state_vec_buf[len] = 0;
2083 return _state_vec_buf;
2084 }
2085
2086 void GenerateOopMap::print_time() {
2087 tty->print_cr ("Accumulated oopmap times:");
2088 tty->print_cr ("---------------------------");
2089 tty->print_cr (" Total : %3.3f sec.", GenerateOopMap::_total_oopmap_time.seconds());
2090 tty->print_cr (" (%3.0f bytecodes per sec) ",
2091 GenerateOopMap::_total_byte_count / GenerateOopMap::_total_oopmap_time.seconds());
2092 }
2093
2094 //
2095 // ============ Main Entry Point ===========
2096 //
2097 GenerateOopMap::GenerateOopMap(const methodHandle& method) {
2098 // We have to initialize all variables here, that can be queried directly
2099 _method = method;
2100 _max_locals=0;
2101 _init_vars = NULL;
2102
2103 #ifndef PRODUCT
2104 // If we are doing a detailed trace, include the regular trace information.
2105 if (TraceNewOopMapGenerationDetailed) {
2106 TraceNewOopMapGeneration = true;
2107 }
2108 #endif
2109 }
2110
2111 void GenerateOopMap::compute_map(TRAPS) {
2112 #ifndef PRODUCT
2113 if (TimeOopMap2) {
2114 method()->print_short_name(tty);
2115 tty->print(" ");
2116 }
2117 if (TimeOopMap) {
2118 _total_byte_count += method()->code_size();
2119 }
2120 #endif
2121 TraceTime t_single("oopmap time", TimeOopMap2);
2122 TraceTime t_all(NULL, &_total_oopmap_time, TimeOopMap);
2123
2124 // Initialize values
2125 _got_error = false;
2126 _conflict = false;
2127 _max_locals = method()->max_locals();
2128 _max_stack = method()->max_stack();
2129 _has_exceptions = (method()->has_exception_handler());
2130 _nof_refval_conflicts = 0;
2131 _init_vars = new GrowableArray<intptr_t>(5); // There are seldom more than 5 init_vars
2132 _report_result = false;
2133 _report_result_for_send = false;
2134 _new_var_map = NULL;
2135 _ret_adr_tos = new GrowableArray<intptr_t>(5); // 5 seems like a good number;
2136 _did_rewriting = false;
2137 _did_relocation = false;
2138
2139 if (TraceNewOopMapGeneration) {
2140 tty->print("Method name: %s\n", method()->name()->as_C_string());
2141 if (Verbose) {
2142 _method->print_codes();
2143 tty->print_cr("Exception table:");
2144 ExceptionTable excps(method());
2145 for(int i = 0; i < excps.length(); i ++) {
2146 tty->print_cr("[%d - %d] -> %d",
2147 excps.start_pc(i), excps.end_pc(i), excps.handler_pc(i));
2148 }
2149 }
2150 }
2151
2152 // if no code - do nothing
2153 // compiler needs info
2154 if (method()->code_size() == 0 || _max_locals + method()->max_stack() == 0) {
2155 fill_stackmap_prolog(0);
2156 fill_stackmap_epilog();
2157 return;
2158 }
2159 // Step 1: Compute all jump targets and their return value
2160 if (!_got_error)
2161 _rt.compute_ret_table(_method);
2162
2163 // Step 2: Find all basic blocks and count GC points
2164 if (!_got_error)
2165 mark_bbheaders_and_count_gc_points();
2166
2167 // Step 3: Calculate stack maps
2168 if (!_got_error)
2169 do_interpretation();
2170
2171 // Step 4:Return results
2172 if (!_got_error && report_results())
2173 report_result();
2174
2175 if (_got_error) {
2176 THROW_HANDLE(_exception);
2177 }
2178 }
2179
2180 // Error handling methods
2181 // These methods create an exception for the current thread which is thrown
2182 // at the bottom of the call stack, when it returns to compute_map(). The
2183 // _got_error flag controls execution. NOT TODO: The VM exception propagation
2184 // mechanism using TRAPS/CHECKs could be used here instead but it would need
2185 // to be added as a parameter to every function and checked for every call.
2186 // The tons of extra code it would generate didn't seem worth the change.
2187 //
2188 void GenerateOopMap::error_work(const char *format, va_list ap) {
2189 _got_error = true;
2190 char msg_buffer[512];
2191 vsnprintf(msg_buffer, sizeof(msg_buffer), format, ap);
2192 // Append method name
2193 char msg_buffer2[512];
2194 jio_snprintf(msg_buffer2, sizeof(msg_buffer2), "%s in method %s", msg_buffer, method()->name()->as_C_string());
2195 if (Thread::current()->can_call_java()) {
2196 _exception = Exceptions::new_exception(Thread::current(),
2197 vmSymbols::java_lang_LinkageError(), msg_buffer2);
2198 } else {
2199 // We cannot instantiate an exception object from a compiler thread.
2200 // Exit the VM with a useful error message.
2201 fatal("%s", msg_buffer2);
2202 }
2203 }
2204
2205 void GenerateOopMap::report_error(const char *format, ...) {
2206 va_list ap;
2207 va_start(ap, format);
2208 error_work(format, ap);
2209 }
2210
2211 void GenerateOopMap::verify_error(const char *format, ...) {
2212 // We do not distinguish between different types of errors for verification
2213 // errors. Let the verifier give a better message.
2214 report_error("Illegal class file encountered. Try running with -Xverify:all");
2215 }
2216
2217 //
2218 // Report result opcodes
2219 //
2220 void GenerateOopMap::report_result() {
2221
2222 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass");
2223
2224 // We now want to report the result of the parse
2225 _report_result = true;
2226
2227 // Prolog code
2228 fill_stackmap_prolog(_gc_points);
2229
2230 // Mark everything changed, then do one interpretation pass.
2231 for (int i = 0; i<_bb_count; i++) {
2232 if (_basic_blocks[i].is_reachable()) {
2233 _basic_blocks[i].set_changed(true);
2234 interp_bb(&_basic_blocks[i]);
2235 }
2236 }
2237
2238 // Note: Since we are skipping dead-code when we are reporting results, then
2239 // the no. of encountered gc-points might be fewer than the previously number
2240 // we have counted. (dead-code is a pain - it should be removed before we get here)
2241 fill_stackmap_epilog();
2242
2243 // Report initvars
2244 fill_init_vars(_init_vars);
2245
2246 _report_result = false;
2247 }
2248
2249 void GenerateOopMap::result_for_basicblock(int bci) {
2250 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass for basicblock");
2251
2252 // We now want to report the result of the parse
2253 _report_result = true;
2254
2255 // Find basicblock and report results
2256 BasicBlock* bb = get_basic_block_containing(bci);
2257 guarantee(bb != NULL, "no basic block for bci");
2258 assert(bb->is_reachable(), "getting result from unreachable basicblock");
2259 bb->set_changed(true);
2260 interp_bb(bb);
2261 }
2262
2263 //
2264 // Conflict handling code
2265 //
2266
2267 void GenerateOopMap::record_refval_conflict(int varNo) {
2268 assert(varNo>=0 && varNo< _max_locals, "index out of range");
2269
2270 if (TraceOopMapRewrites) {
2271 tty->print("### Conflict detected (local no: %d)\n", varNo);
2272 }
2273
2274 if (!_new_var_map) {
2275 _new_var_map = NEW_RESOURCE_ARRAY(int, _max_locals);
2276 for (int k = 0; k < _max_locals; k++) _new_var_map[k] = k;
2277 }
2278
2279 if ( _new_var_map[varNo] == varNo) {
2280 // Check if max. number of locals has been reached
2281 if (_max_locals + _nof_refval_conflicts >= MAX_LOCAL_VARS) {
2282 report_error("Rewriting exceeded local variable limit");
2283 return;
2284 }
2285 _new_var_map[varNo] = _max_locals + _nof_refval_conflicts;
2286 _nof_refval_conflicts++;
2287 }
2288 }
2289
2290 void GenerateOopMap::rewrite_refval_conflicts()
2291 {
2292 // We can get here two ways: Either a rewrite conflict was detected, or
2293 // an uninitialize reference was detected. In the second case, we do not
2294 // do any rewriting, we just want to recompute the reference set with the
2295 // new information
2296
2297 int nof_conflicts = 0; // Used for debugging only
2298
2299 if ( _nof_refval_conflicts == 0 )
2300 return;
2301
2302 // Check if rewrites are allowed in this parse.
2303 if (!allow_rewrites() && !IgnoreRewrites) {
2304 fatal("Rewriting method not allowed at this stage");
2305 }
2306
2307
2308 // This following flag is to tempoary supress rewrites. The locals that might conflict will
2309 // all be set to contain values. This is UNSAFE - however, until the rewriting has been completely
2310 // tested it is nice to have.
2311 if (IgnoreRewrites) {
2312 if (Verbose) {
2313 tty->print("rewrites suppressed for local no. ");
2314 for (int l = 0; l < _max_locals; l++) {
2315 if (_new_var_map[l] != l) {
2316 tty->print("%d ", l);
2317 vars()[l] = CellTypeState::value;
2318 }
2319 }
2320 tty->cr();
2321 }
2322
2323 // That was that...
2324 _new_var_map = NULL;
2325 _nof_refval_conflicts = 0;
2326 _conflict = false;
2327
2328 return;
2329 }
2330
2331 // Tracing flag
2332 _did_rewriting = true;
2333
2334 if (TraceOopMapRewrites) {
2335 tty->print_cr("ref/value conflict for method %s - bytecodes are getting rewritten", method()->name()->as_C_string());
2336 method()->print();
2337 method()->print_codes();
2338 }
2339
2340 assert(_new_var_map!=NULL, "nothing to rewrite");
2341 assert(_conflict==true, "We should not be here");
2342
2343 compute_ret_adr_at_TOS();
2344 if (!_got_error) {
2345 for (int k = 0; k < _max_locals && !_got_error; k++) {
2346 if (_new_var_map[k] != k) {
2347 if (TraceOopMapRewrites) {
2348 tty->print_cr("Rewriting: %d -> %d", k, _new_var_map[k]);
2349 }
2350 rewrite_refval_conflict(k, _new_var_map[k]);
2351 if (_got_error) return;
2352 nof_conflicts++;
2353 }
2354 }
2355 }
2356
2357 assert(nof_conflicts == _nof_refval_conflicts, "sanity check");
2358
2359 // Adjust the number of locals
2360 method()->set_max_locals(_max_locals+_nof_refval_conflicts);
2361 _max_locals += _nof_refval_conflicts;
2362
2363 // That was that...
2364 _new_var_map = NULL;
2365 _nof_refval_conflicts = 0;
2366 }
2367
2368 void GenerateOopMap::rewrite_refval_conflict(int from, int to) {
2369 bool startOver;
2370 do {
2371 // Make sure that the BytecodeStream is constructed in the loop, since
2372 // during rewriting a new method oop is going to be used, and the next time
2373 // around we want to use that.
2374 BytecodeStream bcs(_method);
2375 startOver = false;
2376
2377 while( !startOver && !_got_error &&
2378 // test bcs in case method changed and it became invalid
2379 bcs.next() >=0) {
2380 startOver = rewrite_refval_conflict_inst(&bcs, from, to);
2381 }
2382 } while (startOver && !_got_error);
2383 }
2384
2385 /* If the current instruction is one that uses local variable "from"
2386 in a ref way, change it to use "to". There's a subtle reason why we
2387 renumber the ref uses and not the non-ref uses: non-ref uses may be
2388 2 slots wide (double, long) which would necessitate keeping track of
2389 whether we should add one or two variables to the method. If the change
2390 affected the width of some instruction, returns "TRUE"; otherwise, returns "FALSE".
2391 Another reason for moving ref's value is for solving (addr, ref) conflicts, which
2392 both uses aload/astore methods.
2393 */
2394 bool GenerateOopMap::rewrite_refval_conflict_inst(BytecodeStream *itr, int from, int to) {
2395 Bytecodes::Code bc = itr->code();
2396 int index;
2397 int bci = itr->bci();
2398
2399 if (is_aload(itr, &index) && index == from) {
2400 if (TraceOopMapRewrites) {
2401 tty->print_cr("Rewriting aload at bci: %d", bci);
2402 }
2403 return rewrite_load_or_store(itr, Bytecodes::_aload, Bytecodes::_aload_0, to);
2404 }
2405
2406 if (is_astore(itr, &index) && index == from) {
2407 if (!stack_top_holds_ret_addr(bci)) {
2408 if (TraceOopMapRewrites) {
2409 tty->print_cr("Rewriting astore at bci: %d", bci);
2410 }
2411 return rewrite_load_or_store(itr, Bytecodes::_astore, Bytecodes::_astore_0, to);
2412 } else {
2413 if (TraceOopMapRewrites) {
2414 tty->print_cr("Supress rewriting of astore at bci: %d", bci);
2415 }
2416 }
2417 }
2418
2419 return false;
2420 }
2421
2422 // The argument to this method is:
2423 // bc : Current bytecode
2424 // bcN : either _aload or _astore
2425 // bc0 : either _aload_0 or _astore_0
2426 bool GenerateOopMap::rewrite_load_or_store(BytecodeStream *bcs, Bytecodes::Code bcN, Bytecodes::Code bc0, unsigned int varNo) {
2427 assert(bcN == Bytecodes::_astore || bcN == Bytecodes::_aload, "wrong argument (bcN)");
2428 assert(bc0 == Bytecodes::_astore_0 || bc0 == Bytecodes::_aload_0, "wrong argument (bc0)");
2429 int ilen = Bytecodes::length_at(_method(), bcs->bcp());
2430 int newIlen;
2431
2432 if (ilen == 4) {
2433 // Original instruction was wide; keep it wide for simplicity
2434 newIlen = 4;
2435 } else if (varNo < 4)
2436 newIlen = 1;
2437 else if (varNo >= 256)
2438 newIlen = 4;
2439 else
2440 newIlen = 2;
2441
2442 // If we need to relocate in order to patch the byte, we
2443 // do the patching in a temp. buffer, that is passed to the reloc.
2444 // The patching of the bytecode stream is then done by the Relocator.
2445 // This is neccesary, since relocating the instruction at a certain bci, might
2446 // also relocate that instruction, e.g., if a _goto before it gets widen to a _goto_w.
2447 // Hence, we do not know which bci to patch after relocation.
2448
2449 assert(newIlen <= 4, "sanity check");
2450 u_char inst_buffer[4]; // Max. instruction size is 4.
2451 address bcp;
2452
2453 if (newIlen != ilen) {
2454 // Relocation needed do patching in temp. buffer
2455 bcp = (address)inst_buffer;
2456 } else {
2457 bcp = _method->bcp_from(bcs->bci());
2458 }
2459
2460 // Patch either directly in Method* or in temp. buffer
2461 if (newIlen == 1) {
2462 assert(varNo < 4, "varNo too large");
2463 *bcp = bc0 + varNo;
2464 } else if (newIlen == 2) {
2465 assert(varNo < 256, "2-byte index needed!");
2466 *(bcp + 0) = bcN;
2467 *(bcp + 1) = varNo;
2468 } else {
2469 assert(newIlen == 4, "Wrong instruction length");
2470 *(bcp + 0) = Bytecodes::_wide;
2471 *(bcp + 1) = bcN;
2472 Bytes::put_Java_u2(bcp+2, varNo);
2473 }
2474
2475 if (newIlen != ilen) {
2476 expand_current_instr(bcs->bci(), ilen, newIlen, inst_buffer);
2477 }
2478
2479
2480 return (newIlen != ilen);
2481 }
2482
2483 class RelocCallback : public RelocatorListener {
2484 private:
2485 GenerateOopMap* _gom;
2486 public:
2487 RelocCallback(GenerateOopMap* gom) { _gom = gom; };
2488
2489 // Callback method
2490 virtual void relocated(int bci, int delta, int new_code_length) {
2491 _gom->update_basic_blocks (bci, delta, new_code_length);
2492 _gom->update_ret_adr_at_TOS(bci, delta);
2493 _gom->_rt.update_ret_table (bci, delta);
2494 }
2495 };
2496
2497 // Returns true if expanding was succesful. Otherwise, reports an error and
2498 // returns false.
2499 void GenerateOopMap::expand_current_instr(int bci, int ilen, int newIlen, u_char inst_buffer[]) {
2500 Thread *THREAD = Thread::current(); // Could really have TRAPS argument.
2501 RelocCallback rcb(this);
2502 Relocator rc(_method, &rcb);
2503 methodHandle m= rc.insert_space_at(bci, newIlen, inst_buffer, THREAD);
2504 if (m.is_null() || HAS_PENDING_EXCEPTION) {
2505 report_error("could not rewrite method - exception occurred or bytecode buffer overflow");
2506 return;
2507 }
2508
2509 // Relocator returns a new method oop.
2510 _did_relocation = true;
2511 _method = m;
2512 }
2513
2514
2515 bool GenerateOopMap::is_astore(BytecodeStream *itr, int *index) {
2516 Bytecodes::Code bc = itr->code();
2517 switch(bc) {
2518 case Bytecodes::_astore_0:
2519 case Bytecodes::_astore_1:
2520 case Bytecodes::_astore_2:
2521 case Bytecodes::_astore_3:
2522 *index = bc - Bytecodes::_astore_0;
2523 return true;
2524 case Bytecodes::_astore:
2525 *index = itr->get_index();
2526 return true;
2527 default:
2528 return false;
2529 }
2530 }
2531
2532 bool GenerateOopMap::is_aload(BytecodeStream *itr, int *index) {
2533 Bytecodes::Code bc = itr->code();
2534 switch(bc) {
2535 case Bytecodes::_aload_0:
2536 case Bytecodes::_aload_1:
2537 case Bytecodes::_aload_2:
2538 case Bytecodes::_aload_3:
2539 *index = bc - Bytecodes::_aload_0;
2540 return true;
2541
2542 case Bytecodes::_aload:
2543 *index = itr->get_index();
2544 return true;
2545
2546 default:
2547 return false;
2548 }
2549 }
2550
2551
2552 // Return true iff the top of the operand stack holds a return address at
2553 // the current instruction
2554 bool GenerateOopMap::stack_top_holds_ret_addr(int bci) {
2555 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2556 if (_ret_adr_tos->at(i) == bci)
2557 return true;
2558 }
2559
2560 return false;
2561 }
2562
2563 void GenerateOopMap::compute_ret_adr_at_TOS() {
2564 assert(_ret_adr_tos != NULL, "must be initialized");
2565 _ret_adr_tos->clear();
2566
2567 for (int i = 0; i < bb_count(); i++) {
2568 BasicBlock* bb = &_basic_blocks[i];
2569
2570 // Make sure to only check basicblocks that are reachable
2571 if (bb->is_reachable()) {
2572
2573 // For each Basic block we check all instructions
2574 BytecodeStream bcs(_method);
2575 bcs.set_interval(bb->_bci, next_bb_start_pc(bb));
2576
2577 restore_state(bb);
2578
2579 while (bcs.next()>=0 && !_got_error) {
2580 // TDT: should this be is_good_address() ?
2581 if (_stack_top > 0 && stack()[_stack_top-1].is_address()) {
2582 _ret_adr_tos->append(bcs.bci());
2583 if (TraceNewOopMapGeneration) {
2584 tty->print_cr("Ret_adr TOS at bci: %d", bcs.bci());
2585 }
2586 }
2587 interp1(&bcs);
2588 }
2589 }
2590 }
2591 }
2592
2593 void GenerateOopMap::update_ret_adr_at_TOS(int bci, int delta) {
2594 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2595 int v = _ret_adr_tos->at(i);
2596 if (v > bci) _ret_adr_tos->at_put(i, v + delta);
2597 }
2598 }
2599
2600 // ===================================================================
2601
2602 #ifndef PRODUCT
2603 int ResolveOopMapConflicts::_nof_invocations = 0;
2604 int ResolveOopMapConflicts::_nof_rewrites = 0;
2605 int ResolveOopMapConflicts::_nof_relocations = 0;
2606 #endif
2607
2608 methodHandle ResolveOopMapConflicts::do_potential_rewrite(TRAPS) {
2609 compute_map(CHECK_(methodHandle()));
2610
2611 #ifndef PRODUCT
2612 // Tracking and statistics
2613 if (PrintRewrites) {
2614 _nof_invocations++;
2615 if (did_rewriting()) {
2616 _nof_rewrites++;
2617 if (did_relocation()) _nof_relocations++;
2618 tty->print("Method was rewritten %s: ", (did_relocation()) ? "and relocated" : "");
2619 method()->print_value(); tty->cr();
2620 tty->print_cr("Cand.: %d rewrts: %d (%d%%) reloc.: %d (%d%%)",
2621 _nof_invocations,
2622 _nof_rewrites, (_nof_rewrites * 100) / _nof_invocations,
2623 _nof_relocations, (_nof_relocations * 100) / _nof_invocations);
2624 }
2625 }
2626 #endif
2627 return methodHandle(THREAD, method());
2628 }