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 "interpreter/bytecodeStream.hpp"
27 #include "logging/log.hpp"
28 #include "logging/logStream.hpp"
29 #include "memory/allocation.inline.hpp"
30 #include "oops/constantPool.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/os.hpp"
37 #include "runtime/relocator.hpp"
38 #include "runtime/timerTrace.hpp"
39 #include "utilities/bitMap.inline.hpp"
40 #include "utilities/ostream.hpp"
41
42 //
43 //
44 // Compute stack layouts for each instruction in method.
45 //
46 // Problems:
47 // - What to do about jsr with different types of local vars?
48 // Need maps that are conditional on jsr path?
49 // - Jsr and exceptions should be done more efficiently (the retAddr stuff)
50 //
51 // Alternative:
52 // - Could extend verifier to provide this information.
53 // For: one fewer abstract interpreter to maintain. Against: the verifier
54 // solves a bigger problem so slower (undesirable to force verification of
55 // everything?).
56 //
57 // Algorithm:
58 // Partition bytecodes into basic blocks
59 // For each basic block: store entry state (vars, stack). For instructions
60 // inside basic blocks we do not store any state (instead we recompute it
61 // from state produced by previous instruction).
62 //
63 // Perform abstract interpretation of bytecodes over this lattice:
64 //
65 // _--'#'--_
66 // / / \ \
67 // / / \ \
68 // / | | \
69 // 'r' 'v' 'p' ' '
70 // \ | | /
71 // \ \ / /
72 // \ \ / /
73 // -- '@' --
74 //
75 // '#' top, result of conflict merge
76 // 'r' reference type
77 // 'v' value type
78 // 'p' pc type for jsr/ret
79 // ' ' uninitialized; never occurs on operand stack in Java
80 // '@' bottom/unexecuted; initial state each bytecode.
81 //
82 // Basic block headers are the only merge points. We use this iteration to
83 // compute the information:
84 //
85 // find basic blocks;
86 // initialize them with uninitialized state;
87 // initialize first BB according to method signature;
88 // mark first BB changed
89 // while (some BB is changed) do {
90 // perform abstract interpration of all bytecodes in BB;
91 // merge exit state of BB into entry state of all successor BBs,
92 // noting if any of these change;
93 // }
94 //
95 // One additional complication is necessary. The jsr instruction pushes
96 // a return PC on the stack (a 'p' type in the abstract interpretation).
97 // To be able to process "ret" bytecodes, we keep track of these return
98 // PC's in a 'retAddrs' structure in abstract interpreter context (when
99 // processing a "ret" bytecodes, it is not sufficient to know that it gets
100 // an argument of the right type 'p'; we need to know which address it
101 // returns to).
102 //
103 // (Note this comment is borrowed form the original author of the algorithm)
104
105 // ComputeCallStack
106 //
107 // Specialization of SignatureIterator - compute the effects of a call
108 //
109 class ComputeCallStack : public SignatureIterator {
110 CellTypeState *_effect;
111 int _idx;
112
113 void setup();
114 void set(CellTypeState state) { _effect[_idx++] = state; }
115 int length() { return _idx; };
116
117 virtual void do_bool () { set(CellTypeState::value); };
118 virtual void do_char () { set(CellTypeState::value); };
119 virtual void do_float () { set(CellTypeState::value); };
120 virtual void do_byte () { set(CellTypeState::value); };
121 virtual void do_short () { set(CellTypeState::value); };
122 virtual void do_int () { set(CellTypeState::value); };
123 virtual void do_void () { set(CellTypeState::bottom);};
124 virtual void do_object(int begin, int end) { set(CellTypeState::ref); };
125 virtual void do_valuetype(int begin, int end) { set(CellTypeState::ref); };
126 virtual void do_array (int begin, int end) { set(CellTypeState::ref); };
127
128 void do_double() { set(CellTypeState::value);
129 set(CellTypeState::value); }
130 void do_long () { set(CellTypeState::value);
131 set(CellTypeState::value); }
132
133 public:
134 ComputeCallStack(Symbol* signature) : SignatureIterator(signature) {};
135
136 // Compute methods
137 int compute_for_parameters(bool is_static, CellTypeState *effect) {
138 _idx = 0;
139 _effect = effect;
140
141 if (!is_static) {
142 effect[_idx++] = CellTypeState::ref;
143 }
144
145 iterate_parameters();
146
147 return length();
148 };
149
150 int compute_for_returntype(CellTypeState *effect) {
151 _idx = 0;
152 _effect = effect;
153 iterate_returntype();
154 set(CellTypeState::bottom); // Always terminate with a bottom state, so ppush works
155
156 return length();
157 }
158 };
159
160 //=========================================================================================
161 // ComputeEntryStack
162 //
163 // Specialization of SignatureIterator - in order to set up first stack frame
164 //
165 class ComputeEntryStack : public SignatureIterator {
166 CellTypeState *_effect;
167 int _idx;
168
169 void setup();
170 void set(CellTypeState state) { _effect[_idx++] = state; }
171 int length() { return _idx; };
172
173 virtual void do_bool () { set(CellTypeState::value); };
174 virtual void do_char () { set(CellTypeState::value); };
175 virtual void do_float () { set(CellTypeState::value); };
176 virtual void do_byte () { set(CellTypeState::value); };
177 virtual void do_short () { set(CellTypeState::value); };
178 virtual void do_int () { set(CellTypeState::value); };
179 virtual void do_void () { set(CellTypeState::bottom);};
180 virtual void do_object(int begin, int end) { set(CellTypeState::make_slot_ref(_idx)); }
181 virtual void do_valuetype(int begin, int end) { set(CellTypeState::make_slot_ref(_idx)); }
182 virtual void do_array (int begin, int end) { set(CellTypeState::make_slot_ref(_idx)); }
183
184 void do_double() { set(CellTypeState::value);
185 set(CellTypeState::value); }
186 void do_long () { set(CellTypeState::value);
187 set(CellTypeState::value); }
188
189 public:
190 ComputeEntryStack(Symbol* signature) : SignatureIterator(signature) {};
191
192 // Compute methods
193 int compute_for_parameters(bool is_static, CellTypeState *effect) {
194 _idx = 0;
195 _effect = effect;
196
197 if (!is_static)
198 effect[_idx++] = CellTypeState::make_slot_ref(0);
199
200 iterate_parameters();
201
202 return length();
203 };
204
205 int compute_for_returntype(CellTypeState *effect) {
206 _idx = 0;
207 _effect = effect;
208 iterate_returntype();
209 set(CellTypeState::bottom); // Always terminate with a bottom state, so ppush works
210
211 return length();
212 }
213 };
214
215 //=====================================================================================
216 //
217 // Implementation of RetTable/RetTableEntry
218 //
219 // Contains function to itereate through all bytecodes
220 // and find all return entry points
221 //
222 int RetTable::_init_nof_entries = 10;
223 int RetTableEntry::_init_nof_jsrs = 5;
224
225 RetTableEntry::RetTableEntry(int target, RetTableEntry *next) {
226 _target_bci = target;
227 _jsrs = new GrowableArray<intptr_t>(_init_nof_jsrs);
228 _next = next;
229 }
230
231 void RetTableEntry::add_delta(int bci, int delta) {
232 if (_target_bci > bci) _target_bci += delta;
233
234 for (int k = 0; k < _jsrs->length(); k++) {
235 int jsr = _jsrs->at(k);
236 if (jsr > bci) _jsrs->at_put(k, jsr+delta);
237 }
238 }
239
240 void RetTable::compute_ret_table(const methodHandle& method) {
241 BytecodeStream i(method);
242 Bytecodes::Code bytecode;
243
244 while( (bytecode = i.next()) >= 0) {
245 switch (bytecode) {
246 case Bytecodes::_jsr:
247 add_jsr(i.next_bci(), i.dest());
248 break;
249 case Bytecodes::_jsr_w:
250 add_jsr(i.next_bci(), i.dest_w());
251 break;
252 default:
253 break;
254 }
255 }
256 }
257
258 void RetTable::add_jsr(int return_bci, int target_bci) {
259 RetTableEntry* entry = _first;
260
261 // Scan table for entry
262 for (;entry && entry->target_bci() != target_bci; entry = entry->next());
263
264 if (!entry) {
265 // Allocate new entry and put in list
266 entry = new RetTableEntry(target_bci, _first);
267 _first = entry;
268 }
269
270 // Now "entry" is set. Make sure that the entry is initialized
271 // and has room for the new jsr.
272 entry->add_jsr(return_bci);
273 }
274
275 RetTableEntry* RetTable::find_jsrs_for_target(int targBci) {
276 RetTableEntry *cur = _first;
277
278 while(cur) {
279 assert(cur->target_bci() != -1, "sanity check");
280 if (cur->target_bci() == targBci) return cur;
281 cur = cur->next();
282 }
283 ShouldNotReachHere();
284 return NULL;
285 }
286
287 // The instruction at bci is changing size by "delta". Update the return map.
288 void RetTable::update_ret_table(int bci, int delta) {
289 RetTableEntry *cur = _first;
290 while(cur) {
291 cur->add_delta(bci, delta);
292 cur = cur->next();
293 }
294 }
295
296 //
297 // Celltype state
298 //
299
300 CellTypeState CellTypeState::bottom = CellTypeState::make_bottom();
301 CellTypeState CellTypeState::uninit = CellTypeState::make_any(uninit_value);
302 CellTypeState CellTypeState::ref = CellTypeState::make_any(ref_conflict);
303 CellTypeState CellTypeState::value = CellTypeState::make_any(val_value);
304 CellTypeState CellTypeState::refUninit = CellTypeState::make_any(ref_conflict | uninit_value);
305 CellTypeState CellTypeState::top = CellTypeState::make_top();
306 CellTypeState CellTypeState::addr = CellTypeState::make_any(addr_conflict);
307
308 // Commonly used constants
309 static CellTypeState epsilonCTS[1] = { CellTypeState::bottom };
310 static CellTypeState refCTS = CellTypeState::ref;
311 static CellTypeState valCTS = CellTypeState::value;
312 static CellTypeState vCTS[2] = { CellTypeState::value, CellTypeState::bottom };
313 static CellTypeState rCTS[2] = { CellTypeState::ref, CellTypeState::bottom };
314 static CellTypeState rrCTS[3] = { CellTypeState::ref, CellTypeState::ref, CellTypeState::bottom };
315 static CellTypeState vrCTS[3] = { CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
316 static CellTypeState vvCTS[3] = { CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
317 static CellTypeState rvrCTS[4] = { CellTypeState::ref, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
318 static CellTypeState vvrCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
319 static CellTypeState vvvCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
320 static CellTypeState vvvrCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
321 static CellTypeState vvvvCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
322
323 char CellTypeState::to_char() const {
324 if (can_be_reference()) {
325 if (can_be_value() || can_be_address())
326 return '#'; // Conflict that needs to be rewritten
327 else
328 return 'r';
329 } else if (can_be_value())
330 return 'v';
331 else if (can_be_address())
332 return 'p';
333 else if (can_be_uninit())
334 return ' ';
335 else
336 return '@';
337 }
338
339
340 // Print a detailed CellTypeState. Indicate all bits that are set. If
341 // the CellTypeState represents an address or a reference, print the
342 // value of the additional information.
343 void CellTypeState::print(outputStream *os) {
344 if (can_be_address()) {
345 os->print("(p");
346 } else {
347 os->print("( ");
348 }
349 if (can_be_reference()) {
350 os->print("r");
351 } else {
352 os->print(" ");
353 }
354 if (can_be_value()) {
355 os->print("v");
356 } else {
357 os->print(" ");
358 }
359 if (can_be_uninit()) {
360 os->print("u|");
361 } else {
362 os->print(" |");
363 }
364 if (is_info_top()) {
365 os->print("Top)");
366 } else if (is_info_bottom()) {
367 os->print("Bot)");
368 } else {
369 if (is_reference()) {
370 int info = get_info();
371 int data = info & ~(ref_not_lock_bit | ref_slot_bit);
372 if (info & ref_not_lock_bit) {
373 // Not a monitor lock reference.
374 if (info & ref_slot_bit) {
375 // slot
376 os->print("slot%d)", data);
377 } else {
378 // line
379 os->print("line%d)", data);
380 }
381 } else {
382 // lock
383 os->print("lock%d)", data);
384 }
385 } else {
386 os->print("%d)", get_info());
387 }
388 }
389 }
390
391 //
392 // Basicblock handling methods
393 //
394
395 void GenerateOopMap::initialize_bb() {
396 _gc_points = 0;
397 _bb_count = 0;
398 _bb_hdr_bits.reinitialize(method()->code_size());
399 }
400
401 void GenerateOopMap::bb_mark_fct(GenerateOopMap *c, int bci, int *data) {
402 assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
403 if (c->is_bb_header(bci))
404 return;
405
406 if (TraceNewOopMapGeneration) {
407 tty->print_cr("Basicblock#%d begins at: %d", c->_bb_count, bci);
408 }
409 c->set_bbmark_bit(bci);
410 c->_bb_count++;
411 }
412
413
414 void GenerateOopMap::mark_bbheaders_and_count_gc_points() {
415 initialize_bb();
416
417 bool fellThrough = false; // False to get first BB marked.
418
419 // First mark all exception handlers as start of a basic-block
420 ExceptionTable excps(method());
421 for(int i = 0; i < excps.length(); i ++) {
422 bb_mark_fct(this, excps.handler_pc(i), NULL);
423 }
424
425 // Then iterate through the code
426 BytecodeStream bcs(_method);
427 Bytecodes::Code bytecode;
428
429 while( (bytecode = bcs.next()) >= 0) {
430 int bci = bcs.bci();
431
432 if (!fellThrough)
433 bb_mark_fct(this, bci, NULL);
434
435 fellThrough = jump_targets_do(&bcs, &GenerateOopMap::bb_mark_fct, NULL);
436
437 /* We will also mark successors of jsr's as basic block headers. */
438 switch (bytecode) {
439 case Bytecodes::_jsr:
440 assert(!fellThrough, "should not happen");
441 bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), NULL);
442 break;
443 case Bytecodes::_jsr_w:
444 assert(!fellThrough, "should not happen");
445 bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), NULL);
446 break;
447 default:
448 break;
449 }
450
451 if (possible_gc_point(&bcs))
452 _gc_points++;
453 }
454 }
455
456 void GenerateOopMap::set_bbmark_bit(int bci) {
457 _bb_hdr_bits.at_put(bci, true);
458 }
459
460 void GenerateOopMap::reachable_basicblock(GenerateOopMap *c, int bci, int *data) {
461 assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
462 BasicBlock* bb = c->get_basic_block_at(bci);
463 if (bb->is_dead()) {
464 bb->mark_as_alive();
465 *data = 1; // Mark basicblock as changed
466 }
467 }
468
469
470 void GenerateOopMap::mark_reachable_code() {
471 int change = 1; // int to get function pointers to work
472
473 // Mark entry basic block as alive and all exception handlers
474 _basic_blocks[0].mark_as_alive();
475 ExceptionTable excps(method());
476 for(int i = 0; i < excps.length(); i++) {
477 BasicBlock *bb = get_basic_block_at(excps.handler_pc(i));
478 // If block is not already alive (due to multiple exception handlers to same bb), then
479 // make it alive
480 if (bb->is_dead()) bb->mark_as_alive();
481 }
482
483 BytecodeStream bcs(_method);
484
485 // Iterate through all basic blocks until we reach a fixpoint
486 while (change) {
487 change = 0;
488
489 for (int i = 0; i < _bb_count; i++) {
490 BasicBlock *bb = &_basic_blocks[i];
491 if (bb->is_alive()) {
492 // Position bytecodestream at last bytecode in basicblock
493 bcs.set_start(bb->_end_bci);
494 bcs.next();
495 Bytecodes::Code bytecode = bcs.code();
496 int bci = bcs.bci();
497 assert(bci == bb->_end_bci, "wrong bci");
498
499 bool fell_through = jump_targets_do(&bcs, &GenerateOopMap::reachable_basicblock, &change);
500
501 // We will also mark successors of jsr's as alive.
502 switch (bytecode) {
503 case Bytecodes::_jsr:
504 case Bytecodes::_jsr_w:
505 assert(!fell_through, "should not happen");
506 reachable_basicblock(this, bci + Bytecodes::length_for(bytecode), &change);
507 break;
508 default:
509 break;
510 }
511 if (fell_through) {
512 // Mark successor as alive
513 if (bb[1].is_dead()) {
514 bb[1].mark_as_alive();
515 change = 1;
516 }
517 }
518 }
519 }
520 }
521 }
522
523 /* If the current instruction in "c" has no effect on control flow,
524 returns "true". Otherwise, calls "jmpFct" one or more times, with
525 "c", an appropriate "pcDelta", and "data" as arguments, then
526 returns "false". There is one exception: if the current
527 instruction is a "ret", returns "false" without calling "jmpFct".
528 Arrangements for tracking the control flow of a "ret" must be made
529 externally. */
530 bool GenerateOopMap::jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int *data) {
531 int bci = bcs->bci();
532
533 switch (bcs->code()) {
534 case Bytecodes::_ifeq:
535 case Bytecodes::_ifne:
536 case Bytecodes::_iflt:
537 case Bytecodes::_ifge:
538 case Bytecodes::_ifgt:
539 case Bytecodes::_ifle:
540 case Bytecodes::_if_icmpeq:
541 case Bytecodes::_if_icmpne:
542 case Bytecodes::_if_icmplt:
543 case Bytecodes::_if_icmpge:
544 case Bytecodes::_if_icmpgt:
545 case Bytecodes::_if_icmple:
546 case Bytecodes::_if_acmpeq:
547 case Bytecodes::_if_acmpne:
548 case Bytecodes::_ifnull:
549 case Bytecodes::_ifnonnull:
550 (*jmpFct)(this, bcs->dest(), data);
551 (*jmpFct)(this, bci + 3, data);
552 break;
553
554 case Bytecodes::_goto:
555 (*jmpFct)(this, bcs->dest(), data);
556 break;
557 case Bytecodes::_goto_w:
558 (*jmpFct)(this, bcs->dest_w(), data);
559 break;
560 case Bytecodes::_tableswitch:
561 { Bytecode_tableswitch tableswitch(method(), bcs->bcp());
562 int len = tableswitch.length();
563
564 (*jmpFct)(this, bci + tableswitch.default_offset(), data); /* Default. jump address */
565 while (--len >= 0) {
566 (*jmpFct)(this, bci + tableswitch.dest_offset_at(len), data);
567 }
568 break;
569 }
570
571 case Bytecodes::_lookupswitch:
572 { Bytecode_lookupswitch lookupswitch(method(), bcs->bcp());
573 int npairs = lookupswitch.number_of_pairs();
574 (*jmpFct)(this, bci + lookupswitch.default_offset(), data); /* Default. */
575 while(--npairs >= 0) {
576 LookupswitchPair pair = lookupswitch.pair_at(npairs);
577 (*jmpFct)(this, bci + pair.offset(), data);
578 }
579 break;
580 }
581 case Bytecodes::_jsr:
582 assert(bcs->is_wide()==false, "sanity check");
583 (*jmpFct)(this, bcs->dest(), data);
584
585
586
587 break;
588 case Bytecodes::_jsr_w:
589 (*jmpFct)(this, bcs->dest_w(), data);
590 break;
591 case Bytecodes::_wide:
592 ShouldNotReachHere();
593 return true;
594 break;
595 case Bytecodes::_athrow:
596 case Bytecodes::_ireturn:
597 case Bytecodes::_lreturn:
598 case Bytecodes::_freturn:
599 case Bytecodes::_dreturn:
600 case Bytecodes::_areturn:
601 case Bytecodes::_return:
602 case Bytecodes::_ret:
603 break;
604 default:
605 return true;
606 }
607 return false;
608 }
609
610 /* Requires "pc" to be the head of a basic block; returns that basic
611 block. */
612 BasicBlock *GenerateOopMap::get_basic_block_at(int bci) const {
613 BasicBlock* bb = get_basic_block_containing(bci);
614 assert(bb->_bci == bci, "should have found BB");
615 return bb;
616 }
617
618 // Requires "pc" to be the start of an instruction; returns the basic
619 // block containing that instruction. */
620 BasicBlock *GenerateOopMap::get_basic_block_containing(int bci) const {
621 BasicBlock *bbs = _basic_blocks;
622 int lo = 0, hi = _bb_count - 1;
623
624 while (lo <= hi) {
625 int m = (lo + hi) / 2;
626 int mbci = bbs[m]._bci;
627 int nbci;
628
629 if ( m == _bb_count-1) {
630 assert( bci >= mbci && bci < method()->code_size(), "sanity check failed");
631 return bbs+m;
632 } else {
633 nbci = bbs[m+1]._bci;
634 }
635
636 if ( mbci <= bci && bci < nbci) {
637 return bbs+m;
638 } else if (mbci < bci) {
639 lo = m + 1;
640 } else {
641 assert(mbci > bci, "sanity check");
642 hi = m - 1;
643 }
644 }
645
646 fatal("should have found BB");
647 return NULL;
648 }
649
650 void GenerateOopMap::restore_state(BasicBlock *bb)
651 {
652 memcpy(_state, bb->_state, _state_len*sizeof(CellTypeState));
653 _stack_top = bb->_stack_top;
654 _monitor_top = bb->_monitor_top;
655 }
656
657 int GenerateOopMap::next_bb_start_pc(BasicBlock *bb) {
658 int bbNum = bb - _basic_blocks + 1;
659 if (bbNum == _bb_count)
660 return method()->code_size();
661
662 return _basic_blocks[bbNum]._bci;
663 }
664
665 //
666 // CellType handling methods
667 //
668
669 // Allocate memory and throw LinkageError if failure.
670 #define ALLOC_RESOURCE_ARRAY(var, type, count) \
671 var = NEW_RESOURCE_ARRAY_RETURN_NULL(type, count); \
672 if (var == NULL) { \
673 report_error("Cannot reserve enough memory to analyze this method"); \
674 return; \
675 }
676
677
678 void GenerateOopMap::init_state() {
679 _state_len = _max_locals + _max_stack + _max_monitors;
680 ALLOC_RESOURCE_ARRAY(_state, CellTypeState, _state_len);
681 memset(_state, 0, _state_len * sizeof(CellTypeState));
682 int count = MAX3(_max_locals, _max_stack, _max_monitors) + 1/*for null terminator char */;
683 ALLOC_RESOURCE_ARRAY(_state_vec_buf, char, count);
684 }
685
686 void GenerateOopMap::make_context_uninitialized() {
687 CellTypeState* vs = vars();
688
689 for (int i = 0; i < _max_locals; i++)
690 vs[i] = CellTypeState::uninit;
691
692 _stack_top = 0;
693 _monitor_top = 0;
694 }
695
696 int GenerateOopMap::methodsig_to_effect(Symbol* signature, bool is_static, CellTypeState* effect) {
697 ComputeEntryStack ces(signature);
698 return ces.compute_for_parameters(is_static, effect);
699 }
700
701 // Return result of merging cts1 and cts2.
702 CellTypeState CellTypeState::merge(CellTypeState cts, int slot) const {
703 CellTypeState result;
704
705 assert(!is_bottom() && !cts.is_bottom(),
706 "merge of bottom values is handled elsewhere");
707
708 result._state = _state | cts._state;
709
710 // If the top bit is set, we don't need to do any more work.
711 if (!result.is_info_top()) {
712 assert((result.can_be_address() || result.can_be_reference()),
713 "only addresses and references have non-top info");
714
715 if (!equal(cts)) {
716 // The two values being merged are different. Raise to top.
717 if (result.is_reference()) {
718 result = CellTypeState::make_slot_ref(slot);
719 } else {
720 result._state |= info_conflict;
721 }
722 }
723 }
724 assert(result.is_valid_state(), "checking that CTS merge maintains legal state");
725
726 return result;
727 }
728
729 // Merge the variable state for locals and stack from cts into bbts.
730 bool GenerateOopMap::merge_local_state_vectors(CellTypeState* cts,
731 CellTypeState* bbts) {
732 int i;
733 int len = _max_locals + _stack_top;
734 bool change = false;
735
736 for (i = len - 1; i >= 0; i--) {
737 CellTypeState v = cts[i].merge(bbts[i], i);
738 change = change || !v.equal(bbts[i]);
739 bbts[i] = v;
740 }
741
742 return change;
743 }
744
745 // Merge the monitor stack state from cts into bbts.
746 bool GenerateOopMap::merge_monitor_state_vectors(CellTypeState* cts,
747 CellTypeState* bbts) {
748 bool change = false;
749 if (_max_monitors > 0 && _monitor_top != bad_monitors) {
750 // If there are no monitors in the program, or there has been
751 // a monitor matching error before this point in the program,
752 // then we do not merge in the monitor state.
753
754 int base = _max_locals + _max_stack;
755 int len = base + _monitor_top;
756 for (int i = len - 1; i >= base; i--) {
757 CellTypeState v = cts[i].merge(bbts[i], i);
758
759 // Can we prove that, when there has been a change, it will already
760 // have been detected at this point? That would make this equal
761 // check here unnecessary.
762 change = change || !v.equal(bbts[i]);
763 bbts[i] = v;
764 }
765 }
766
767 return change;
768 }
769
770 void GenerateOopMap::copy_state(CellTypeState *dst, CellTypeState *src) {
771 int len = _max_locals + _stack_top;
772 for (int i = 0; i < len; i++) {
773 if (src[i].is_nonlock_reference()) {
774 dst[i] = CellTypeState::make_slot_ref(i);
775 } else {
776 dst[i] = src[i];
777 }
778 }
779 if (_max_monitors > 0 && _monitor_top != bad_monitors) {
780 int base = _max_locals + _max_stack;
781 len = base + _monitor_top;
782 for (int i = base; i < len; i++) {
783 dst[i] = src[i];
784 }
785 }
786 }
787
788
789 // Merge the states for the current block and the next. As long as a
790 // block is reachable the locals and stack must be merged. If the
791 // stack heights don't match then this is a verification error and
792 // it's impossible to interpret the code. Simultaneously monitor
793 // states are being check to see if they nest statically. If monitor
794 // depths match up then their states are merged. Otherwise the
795 // mismatch is simply recorded and interpretation continues since
796 // monitor matching is purely informational and doesn't say anything
797 // about the correctness of the code.
798 void GenerateOopMap::merge_state_into_bb(BasicBlock *bb) {
799 guarantee(bb != NULL, "null basicblock");
800 assert(bb->is_alive(), "merging state into a dead basicblock");
801
802 if (_stack_top == bb->_stack_top) {
803 // always merge local state even if monitors don't match.
804 if (merge_local_state_vectors(_state, bb->_state)) {
805 bb->set_changed(true);
806 }
807 if (_monitor_top == bb->_monitor_top) {
808 // monitors still match so continue merging monitor states.
809 if (merge_monitor_state_vectors(_state, bb->_state)) {
810 bb->set_changed(true);
811 }
812 } else {
813 if (log_is_enabled(Info, monitormismatch)) {
814 report_monitor_mismatch("monitor stack height merge conflict");
815 }
816 // When the monitor stacks are not matched, we set _monitor_top to
817 // bad_monitors. This signals that, from here on, the monitor stack cannot
818 // be trusted. In particular, monitorexit bytecodes may throw
819 // exceptions. We mark this block as changed so that the change
820 // propagates properly.
821 bb->_monitor_top = bad_monitors;
822 bb->set_changed(true);
823 _monitor_safe = false;
824 }
825 } else if (!bb->is_reachable()) {
826 // First time we look at this BB
827 copy_state(bb->_state, _state);
828 bb->_stack_top = _stack_top;
829 bb->_monitor_top = _monitor_top;
830 bb->set_changed(true);
831 } else {
832 verify_error("stack height conflict: %d vs. %d", _stack_top, bb->_stack_top);
833 }
834 }
835
836 void GenerateOopMap::merge_state(GenerateOopMap *gom, int bci, int* data) {
837 gom->merge_state_into_bb(gom->get_basic_block_at(bci));
838 }
839
840 void GenerateOopMap::set_var(int localNo, CellTypeState cts) {
841 assert(cts.is_reference() || cts.is_value() || cts.is_address(),
842 "wrong celltypestate");
843 if (localNo < 0 || localNo > _max_locals) {
844 verify_error("variable write error: r%d", localNo);
845 return;
846 }
847 vars()[localNo] = cts;
848 }
849
850 CellTypeState GenerateOopMap::get_var(int localNo) {
851 assert(localNo < _max_locals + _nof_refval_conflicts, "variable read error");
852 if (localNo < 0 || localNo > _max_locals) {
853 verify_error("variable read error: r%d", localNo);
854 return valCTS; // just to pick something;
855 }
856 return vars()[localNo];
857 }
858
859 CellTypeState GenerateOopMap::pop() {
860 if ( _stack_top <= 0) {
861 verify_error("stack underflow");
862 return valCTS; // just to pick something
863 }
864 return stack()[--_stack_top];
865 }
866
867 void GenerateOopMap::push(CellTypeState cts) {
868 if ( _stack_top >= _max_stack) {
869 verify_error("stack overflow");
870 return;
871 }
872 stack()[_stack_top++] = cts;
873 }
874
875 CellTypeState GenerateOopMap::monitor_pop() {
876 assert(_monitor_top != bad_monitors, "monitor_pop called on error monitor stack");
877 if (_monitor_top == 0) {
878 // We have detected a pop of an empty monitor stack.
879 _monitor_safe = false;
880 _monitor_top = bad_monitors;
881
882 if (log_is_enabled(Info, monitormismatch)) {
883 report_monitor_mismatch("monitor stack underflow");
884 }
885 return CellTypeState::ref; // just to keep the analysis going.
886 }
887 return monitors()[--_monitor_top];
888 }
889
890 void GenerateOopMap::monitor_push(CellTypeState cts) {
891 assert(_monitor_top != bad_monitors, "monitor_push called on error monitor stack");
892 if (_monitor_top >= _max_monitors) {
893 // Some monitorenter is being executed more than once.
894 // This means that the monitor stack cannot be simulated.
895 _monitor_safe = false;
896 _monitor_top = bad_monitors;
897
898 if (log_is_enabled(Info, monitormismatch)) {
899 report_monitor_mismatch("monitor stack overflow");
900 }
901 return;
902 }
903 monitors()[_monitor_top++] = cts;
904 }
905
906 //
907 // Interpretation handling methods
908 //
909
910 void GenerateOopMap::do_interpretation()
911 {
912 // "i" is just for debugging, so we can detect cases where this loop is
913 // iterated more than once.
914 int i = 0;
915 do {
916 #ifndef PRODUCT
917 if (TraceNewOopMapGeneration) {
918 tty->print("\n\nIteration #%d of do_interpretation loop, method:\n", i);
919 method()->print_name(tty);
920 tty->print("\n\n");
921 }
922 #endif
923 _conflict = false;
924 _monitor_safe = true;
925 // init_state is now called from init_basic_blocks. The length of a
926 // state vector cannot be determined until we have made a pass through
927 // the bytecodes counting the possible monitor entries.
928 if (!_got_error) init_basic_blocks();
929 if (!_got_error) setup_method_entry_state();
930 if (!_got_error) interp_all();
931 if (!_got_error) rewrite_refval_conflicts();
932 i++;
933 } while (_conflict && !_got_error);
934 }
935
936 void GenerateOopMap::init_basic_blocks() {
937 // Note: Could consider reserving only the needed space for each BB's state
938 // (entry stack may not be of maximal height for every basic block).
939 // But cumbersome since we don't know the stack heights yet. (Nor the
940 // monitor stack heights...)
941
942 ALLOC_RESOURCE_ARRAY(_basic_blocks, BasicBlock, _bb_count);
943
944 // Make a pass through the bytecodes. Count the number of monitorenters.
945 // This can be used an upper bound on the monitor stack depth in programs
946 // which obey stack discipline with their monitor usage. Initialize the
947 // known information about basic blocks.
948 BytecodeStream j(_method);
949 Bytecodes::Code bytecode;
950
951 int bbNo = 0;
952 int monitor_count = 0;
953 int prev_bci = -1;
954 while( (bytecode = j.next()) >= 0) {
955 if (j.code() == Bytecodes::_monitorenter) {
956 monitor_count++;
957 }
958
959 int bci = j.bci();
960 if (is_bb_header(bci)) {
961 // Initialize the basicblock structure
962 BasicBlock *bb = _basic_blocks + bbNo;
963 bb->_bci = bci;
964 bb->_max_locals = _max_locals;
965 bb->_max_stack = _max_stack;
966 bb->set_changed(false);
967 bb->_stack_top = BasicBlock::_dead_basic_block; // Initialize all basicblocks are dead.
968 bb->_monitor_top = bad_monitors;
969
970 if (bbNo > 0) {
971 _basic_blocks[bbNo - 1]._end_bci = prev_bci;
972 }
973
974 bbNo++;
975 }
976 // Remember prevous bci.
977 prev_bci = bci;
978 }
979 // Set
980 _basic_blocks[bbNo-1]._end_bci = prev_bci;
981
982
983 // Check that the correct number of basicblocks was found
984 if (bbNo !=_bb_count) {
985 if (bbNo < _bb_count) {
986 verify_error("jump into the middle of instruction?");
987 return;
988 } else {
989 verify_error("extra basic blocks - should not happen?");
990 return;
991 }
992 }
993
994 _max_monitors = monitor_count;
995
996 // Now that we have a bound on the depth of the monitor stack, we can
997 // initialize the CellTypeState-related information.
998 init_state();
999
1000 // We allocate space for all state-vectors for all basicblocks in one huge
1001 // chunk. Then in the next part of the code, we set a pointer in each
1002 // _basic_block that points to each piece.
1003
1004 // The product of bbNo and _state_len can get large if there are lots of
1005 // basic blocks and stack/locals/monitors. Need to check to make sure
1006 // we don't overflow the capacity of a pointer.
1007 if ((unsigned)bbNo > UINTPTR_MAX / sizeof(CellTypeState) / _state_len) {
1008 report_error("The amount of memory required to analyze this method "
1009 "exceeds addressable range");
1010 return;
1011 }
1012
1013 CellTypeState *basicBlockState;
1014 ALLOC_RESOURCE_ARRAY(basicBlockState, CellTypeState, bbNo * _state_len);
1015 memset(basicBlockState, 0, bbNo * _state_len * sizeof(CellTypeState));
1016
1017 // Make a pass over the basicblocks and assign their state vectors.
1018 for (int blockNum=0; blockNum < bbNo; blockNum++) {
1019 BasicBlock *bb = _basic_blocks + blockNum;
1020 bb->_state = basicBlockState + blockNum * _state_len;
1021
1022 #ifdef ASSERT
1023 if (blockNum + 1 < bbNo) {
1024 address bcp = _method->bcp_from(bb->_end_bci);
1025 int bc_len = Bytecodes::java_length_at(_method(), bcp);
1026 assert(bb->_end_bci + bc_len == bb[1]._bci, "unmatched bci info in basicblock");
1027 }
1028 #endif
1029 }
1030 #ifdef ASSERT
1031 { BasicBlock *bb = &_basic_blocks[bbNo-1];
1032 address bcp = _method->bcp_from(bb->_end_bci);
1033 int bc_len = Bytecodes::java_length_at(_method(), bcp);
1034 assert(bb->_end_bci + bc_len == _method->code_size(), "wrong end bci");
1035 }
1036 #endif
1037
1038 // Mark all alive blocks
1039 mark_reachable_code();
1040 }
1041
1042 void GenerateOopMap::setup_method_entry_state() {
1043
1044 // Initialize all locals to 'uninit' and set stack-height to 0
1045 make_context_uninitialized();
1046
1047 // Initialize CellState type of arguments
1048 methodsig_to_effect(method()->signature(), method()->is_static(), vars());
1049
1050 // If some references must be pre-assigned to null, then set that up
1051 initialize_vars();
1052
1053 // This is the start state
1054 merge_state_into_bb(&_basic_blocks[0]);
1055
1056 assert(_basic_blocks[0].changed(), "we are not getting off the ground");
1057 }
1058
1059 // The instruction at bci is changing size by "delta". Update the basic blocks.
1060 void GenerateOopMap::update_basic_blocks(int bci, int delta,
1061 int new_method_size) {
1062 assert(new_method_size >= method()->code_size() + delta,
1063 "new method size is too small");
1064
1065 _bb_hdr_bits.reinitialize(new_method_size);
1066
1067 for(int k = 0; k < _bb_count; k++) {
1068 if (_basic_blocks[k]._bci > bci) {
1069 _basic_blocks[k]._bci += delta;
1070 _basic_blocks[k]._end_bci += delta;
1071 }
1072 _bb_hdr_bits.at_put(_basic_blocks[k]._bci, true);
1073 }
1074 }
1075
1076 //
1077 // Initvars handling
1078 //
1079
1080 void GenerateOopMap::initialize_vars() {
1081 for (int k = 0; k < _init_vars->length(); k++)
1082 _state[_init_vars->at(k)] = CellTypeState::make_slot_ref(k);
1083 }
1084
1085 void GenerateOopMap::add_to_ref_init_set(int localNo) {
1086
1087 if (TraceNewOopMapGeneration)
1088 tty->print_cr("Added init vars: %d", localNo);
1089
1090 // Is it already in the set?
1091 if (_init_vars->contains(localNo) )
1092 return;
1093
1094 _init_vars->append(localNo);
1095 }
1096
1097 //
1098 // Interpreration code
1099 //
1100
1101 void GenerateOopMap::interp_all() {
1102 bool change = true;
1103
1104 while (change && !_got_error) {
1105 change = false;
1106 for (int i = 0; i < _bb_count && !_got_error; i++) {
1107 BasicBlock *bb = &_basic_blocks[i];
1108 if (bb->changed()) {
1109 if (_got_error) return;
1110 change = true;
1111 bb->set_changed(false);
1112 interp_bb(bb);
1113 }
1114 }
1115 }
1116 }
1117
1118 void GenerateOopMap::interp_bb(BasicBlock *bb) {
1119
1120 // We do not want to do anything in case the basic-block has not been initialized. This
1121 // will happen in the case where there is dead-code hang around in a method.
1122 assert(bb->is_reachable(), "should be reachable or deadcode exist");
1123 restore_state(bb);
1124
1125 BytecodeStream itr(_method);
1126
1127 // Set iterator interval to be the current basicblock
1128 int lim_bci = next_bb_start_pc(bb);
1129 itr.set_interval(bb->_bci, lim_bci);
1130 assert(lim_bci != bb->_bci, "must be at least one instruction in a basicblock");
1131 itr.next(); // read first instruction
1132
1133 // Iterates through all bytecodes except the last in a basic block.
1134 // We handle the last one special, since there is controlflow change.
1135 while(itr.next_bci() < lim_bci && !_got_error) {
1136 if (_has_exceptions || _monitor_top != 0) {
1137 // We do not need to interpret the results of exceptional
1138 // continuation from this instruction when the method has no
1139 // exception handlers and the monitor stack is currently
1140 // empty.
1141 do_exception_edge(&itr);
1142 }
1143 interp1(&itr);
1144 itr.next();
1145 }
1146
1147 // Handle last instruction.
1148 if (!_got_error) {
1149 assert(itr.next_bci() == lim_bci, "must point to end");
1150 if (_has_exceptions || _monitor_top != 0) {
1151 do_exception_edge(&itr);
1152 }
1153 interp1(&itr);
1154
1155 bool fall_through = jump_targets_do(&itr, GenerateOopMap::merge_state, NULL);
1156 if (_got_error) return;
1157
1158 if (itr.code() == Bytecodes::_ret) {
1159 assert(!fall_through, "cannot be set if ret instruction");
1160 // Automatically handles 'wide' ret indicies
1161 ret_jump_targets_do(&itr, GenerateOopMap::merge_state, itr.get_index(), NULL);
1162 } else if (fall_through) {
1163 // Hit end of BB, but the instr. was a fall-through instruction,
1164 // so perform transition as if the BB ended in a "jump".
1165 if (lim_bci != bb[1]._bci) {
1166 verify_error("bytecodes fell through last instruction");
1167 return;
1168 }
1169 merge_state_into_bb(bb + 1);
1170 }
1171 }
1172 }
1173
1174 void GenerateOopMap::do_exception_edge(BytecodeStream* itr) {
1175 // Only check exception edge, if bytecode can trap
1176 if (!Bytecodes::can_trap(itr->code())) return;
1177 switch (itr->code()) {
1178 case Bytecodes::_aload_0:
1179 // These bytecodes can trap for rewriting. We need to assume that
1180 // they do not throw exceptions to make the monitor analysis work.
1181 return;
1182
1183 case Bytecodes::_ireturn:
1184 case Bytecodes::_lreturn:
1185 case Bytecodes::_freturn:
1186 case Bytecodes::_dreturn:
1187 case Bytecodes::_areturn:
1188 case Bytecodes::_return:
1189 // If the monitor stack height is not zero when we leave the method,
1190 // then we are either exiting with a non-empty stack or we have
1191 // found monitor trouble earlier in our analysis. In either case,
1192 // assume an exception could be taken here.
1193 if (_monitor_top == 0) {
1194 return;
1195 }
1196 break;
1197
1198 case Bytecodes::_monitorexit:
1199 // If the monitor stack height is bad_monitors, then we have detected a
1200 // monitor matching problem earlier in the analysis. If the
1201 // monitor stack height is 0, we are about to pop a monitor
1202 // off of an empty stack. In either case, the bytecode
1203 // could throw an exception.
1204 if (_monitor_top != bad_monitors && _monitor_top != 0) {
1205 return;
1206 }
1207 break;
1208
1209 default:
1210 break;
1211 }
1212
1213 if (_has_exceptions) {
1214 int bci = itr->bci();
1215 ExceptionTable exct(method());
1216 for(int i = 0; i< exct.length(); i++) {
1217 int start_pc = exct.start_pc(i);
1218 int end_pc = exct.end_pc(i);
1219 int handler_pc = exct.handler_pc(i);
1220 int catch_type = exct.catch_type_index(i);
1221
1222 if (start_pc <= bci && bci < end_pc) {
1223 BasicBlock *excBB = get_basic_block_at(handler_pc);
1224 guarantee(excBB != NULL, "no basic block for exception");
1225 CellTypeState *excStk = excBB->stack();
1226 CellTypeState *cOpStck = stack();
1227 CellTypeState cOpStck_0 = cOpStck[0];
1228 int cOpStackTop = _stack_top;
1229
1230 // Exception stacks are always the same.
1231 assert(method()->max_stack() > 0, "sanity check");
1232
1233 // We remembered the size and first element of "cOpStck"
1234 // above; now we temporarily set them to the appropriate
1235 // values for an exception handler. */
1236 cOpStck[0] = CellTypeState::make_slot_ref(_max_locals);
1237 _stack_top = 1;
1238
1239 merge_state_into_bb(excBB);
1240
1241 // Now undo the temporary change.
1242 cOpStck[0] = cOpStck_0;
1243 _stack_top = cOpStackTop;
1244
1245 // If this is a "catch all" handler, then we do not need to
1246 // consider any additional handlers.
1247 if (catch_type == 0) {
1248 return;
1249 }
1250 }
1251 }
1252 }
1253
1254 // It is possible that none of the exception handlers would have caught
1255 // the exception. In this case, we will exit the method. We must
1256 // ensure that the monitor stack is empty in this case.
1257 if (_monitor_top == 0) {
1258 return;
1259 }
1260
1261 // We pessimistically assume that this exception can escape the
1262 // method. (It is possible that it will always be caught, but
1263 // we don't care to analyse the types of the catch clauses.)
1264
1265 // We don't set _monitor_top to bad_monitors because there are no successors
1266 // to this exceptional exit.
1267
1268 if (log_is_enabled(Info, monitormismatch) && _monitor_safe) {
1269 // We check _monitor_safe so that we only report the first mismatched
1270 // exceptional exit.
1271 report_monitor_mismatch("non-empty monitor stack at exceptional exit");
1272 }
1273 _monitor_safe = false;
1274
1275 }
1276
1277 void GenerateOopMap::report_monitor_mismatch(const char *msg) {
1278 ResourceMark rm;
1279 LogStream ls(Log(monitormismatch)::info());
1280 ls.print("Monitor mismatch in method ");
1281 method()->print_short_name(&ls);
1282 ls.print_cr(": %s", msg);
1283 }
1284
1285 void GenerateOopMap::print_states(outputStream *os,
1286 CellTypeState* vec, int num) {
1287 for (int i = 0; i < num; i++) {
1288 vec[i].print(tty);
1289 }
1290 }
1291
1292 // Print the state values at the current bytecode.
1293 void GenerateOopMap::print_current_state(outputStream *os,
1294 BytecodeStream *currentBC,
1295 bool detailed) {
1296 if (detailed) {
1297 os->print(" %4d vars = ", currentBC->bci());
1298 print_states(os, vars(), _max_locals);
1299 os->print(" %s", Bytecodes::name(currentBC->code()));
1300 } else {
1301 os->print(" %4d vars = '%s' ", currentBC->bci(), state_vec_to_string(vars(), _max_locals));
1302 os->print(" stack = '%s' ", state_vec_to_string(stack(), _stack_top));
1303 if (_monitor_top != bad_monitors) {
1304 os->print(" monitors = '%s' \t%s", state_vec_to_string(monitors(), _monitor_top), Bytecodes::name(currentBC->code()));
1305 } else {
1306 os->print(" [bad monitor stack]");
1307 }
1308 }
1309
1310 switch(currentBC->code()) {
1311 case Bytecodes::_invokevirtual:
1312 case Bytecodes::_invokespecial:
1313 case Bytecodes::_invokestatic:
1314 case Bytecodes::_invokedynamic:
1315 case Bytecodes::_invokeinterface: {
1316 int idx = currentBC->has_index_u4() ? currentBC->get_index_u4() : currentBC->get_index_u2_cpcache();
1317 ConstantPool* cp = method()->constants();
1318 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
1319 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1320 Symbol* signature = cp->symbol_at(signatureIdx);
1321 os->print("%s", signature->as_C_string());
1322 }
1323 default:
1324 break;
1325 }
1326
1327 if (detailed) {
1328 os->cr();
1329 os->print(" stack = ");
1330 print_states(os, stack(), _stack_top);
1331 os->cr();
1332 if (_monitor_top != bad_monitors) {
1333 os->print(" monitors = ");
1334 print_states(os, monitors(), _monitor_top);
1335 } else {
1336 os->print(" [bad monitor stack]");
1337 }
1338 }
1339
1340 os->cr();
1341 }
1342
1343 // Sets the current state to be the state after executing the
1344 // current instruction, starting in the current state.
1345 void GenerateOopMap::interp1(BytecodeStream *itr) {
1346 if (TraceNewOopMapGeneration) {
1347 print_current_state(tty, itr, TraceNewOopMapGenerationDetailed);
1348 }
1349
1350 // Should we report the results? Result is reported *before* the instruction at the current bci is executed.
1351 // However, not for calls. For calls we do not want to include the arguments, so we postpone the reporting until
1352 // they have been popped (in method ppl).
1353 if (_report_result == true) {
1354 switch(itr->code()) {
1355 case Bytecodes::_invokevirtual:
1356 case Bytecodes::_invokespecial:
1357 case Bytecodes::_invokestatic:
1358 case Bytecodes::_invokedynamic:
1359 case Bytecodes::_invokeinterface:
1360 _itr_send = itr;
1361 _report_result_for_send = true;
1362 break;
1363 default:
1364 fill_stackmap_for_opcodes(itr, vars(), stack(), _stack_top);
1365 break;
1366 }
1367 }
1368
1369 // abstract interpretation of current opcode
1370 switch(itr->code()) {
1371 case Bytecodes::_nop: break;
1372 case Bytecodes::_goto: break;
1373 case Bytecodes::_goto_w: break;
1374 case Bytecodes::_iinc: break;
1375 case Bytecodes::_return: do_return_monitor_check();
1376 break;
1377
1378 case Bytecodes::_aconst_null:
1379 case Bytecodes::_new: ppush1(CellTypeState::make_line_ref(itr->bci()));
1380 break;
1381
1382 case Bytecodes::_defaultvalue: ppush1(CellTypeState::make_line_ref(itr->bci())); break;
1383 case Bytecodes::_withfield: do_withfield(itr->get_index_u2_cpcache(), itr->bci()); break;
1384
1385 case Bytecodes::_iconst_m1:
1386 case Bytecodes::_iconst_0:
1387 case Bytecodes::_iconst_1:
1388 case Bytecodes::_iconst_2:
1389 case Bytecodes::_iconst_3:
1390 case Bytecodes::_iconst_4:
1391 case Bytecodes::_iconst_5:
1392 case Bytecodes::_fconst_0:
1393 case Bytecodes::_fconst_1:
1394 case Bytecodes::_fconst_2:
1395 case Bytecodes::_bipush:
1396 case Bytecodes::_sipush: ppush1(valCTS); break;
1397
1398 case Bytecodes::_lconst_0:
1399 case Bytecodes::_lconst_1:
1400 case Bytecodes::_dconst_0:
1401 case Bytecodes::_dconst_1: ppush(vvCTS); break;
1402
1403 case Bytecodes::_ldc2_w: ppush(vvCTS); break;
1404
1405 case Bytecodes::_ldc: // fall through:
1406 case Bytecodes::_ldc_w: do_ldc(itr->bci()); break;
1407
1408 case Bytecodes::_iload:
1409 case Bytecodes::_fload: ppload(vCTS, itr->get_index()); break;
1410
1411 case Bytecodes::_lload:
1412 case Bytecodes::_dload: ppload(vvCTS,itr->get_index()); break;
1413
1414 case Bytecodes::_aload: ppload(rCTS, itr->get_index()); break;
1415
1416 case Bytecodes::_iload_0:
1417 case Bytecodes::_fload_0: ppload(vCTS, 0); break;
1418 case Bytecodes::_iload_1:
1419 case Bytecodes::_fload_1: ppload(vCTS, 1); break;
1420 case Bytecodes::_iload_2:
1421 case Bytecodes::_fload_2: ppload(vCTS, 2); break;
1422 case Bytecodes::_iload_3:
1423 case Bytecodes::_fload_3: ppload(vCTS, 3); break;
1424
1425 case Bytecodes::_lload_0:
1426 case Bytecodes::_dload_0: ppload(vvCTS, 0); break;
1427 case Bytecodes::_lload_1:
1428 case Bytecodes::_dload_1: ppload(vvCTS, 1); break;
1429 case Bytecodes::_lload_2:
1430 case Bytecodes::_dload_2: ppload(vvCTS, 2); break;
1431 case Bytecodes::_lload_3:
1432 case Bytecodes::_dload_3: ppload(vvCTS, 3); break;
1433
1434 case Bytecodes::_aload_0: ppload(rCTS, 0); break;
1435 case Bytecodes::_aload_1: ppload(rCTS, 1); break;
1436 case Bytecodes::_aload_2: ppload(rCTS, 2); break;
1437 case Bytecodes::_aload_3: ppload(rCTS, 3); break;
1438
1439 case Bytecodes::_iaload:
1440 case Bytecodes::_faload:
1441 case Bytecodes::_baload:
1442 case Bytecodes::_caload:
1443 case Bytecodes::_saload: pp(vrCTS, vCTS); break;
1444
1445 case Bytecodes::_laload: pp(vrCTS, vvCTS); break;
1446 case Bytecodes::_daload: pp(vrCTS, vvCTS); break;
1447
1448 case Bytecodes::_aaload: pp_new_ref(vrCTS, itr->bci()); break;
1449
1450 case Bytecodes::_istore:
1451 case Bytecodes::_fstore: ppstore(vCTS, itr->get_index()); break;
1452
1453 case Bytecodes::_lstore:
1454 case Bytecodes::_dstore: ppstore(vvCTS, itr->get_index()); break;
1455
1456 case Bytecodes::_astore: do_astore(itr->get_index()); break;
1457
1458 case Bytecodes::_istore_0:
1459 case Bytecodes::_fstore_0: ppstore(vCTS, 0); break;
1460 case Bytecodes::_istore_1:
1461 case Bytecodes::_fstore_1: ppstore(vCTS, 1); break;
1462 case Bytecodes::_istore_2:
1463 case Bytecodes::_fstore_2: ppstore(vCTS, 2); break;
1464 case Bytecodes::_istore_3:
1465 case Bytecodes::_fstore_3: ppstore(vCTS, 3); break;
1466
1467 case Bytecodes::_lstore_0:
1468 case Bytecodes::_dstore_0: ppstore(vvCTS, 0); break;
1469 case Bytecodes::_lstore_1:
1470 case Bytecodes::_dstore_1: ppstore(vvCTS, 1); break;
1471 case Bytecodes::_lstore_2:
1472 case Bytecodes::_dstore_2: ppstore(vvCTS, 2); break;
1473 case Bytecodes::_lstore_3:
1474 case Bytecodes::_dstore_3: ppstore(vvCTS, 3); break;
1475
1476 case Bytecodes::_astore_0: do_astore(0); break;
1477 case Bytecodes::_astore_1: do_astore(1); break;
1478 case Bytecodes::_astore_2: do_astore(2); break;
1479 case Bytecodes::_astore_3: do_astore(3); break;
1480
1481 case Bytecodes::_iastore:
1482 case Bytecodes::_fastore:
1483 case Bytecodes::_bastore:
1484 case Bytecodes::_castore:
1485 case Bytecodes::_sastore: ppop(vvrCTS); break;
1486 case Bytecodes::_lastore:
1487 case Bytecodes::_dastore: ppop(vvvrCTS); break;
1488 case Bytecodes::_aastore: ppop(rvrCTS); break;
1489
1490 case Bytecodes::_pop: ppop_any(1); break;
1491 case Bytecodes::_pop2: ppop_any(2); break;
1492
1493 case Bytecodes::_dup: ppdupswap(1, "11"); break;
1494 case Bytecodes::_dup_x1: ppdupswap(2, "121"); break;
1495 case Bytecodes::_dup_x2: ppdupswap(3, "1321"); break;
1496 case Bytecodes::_dup2: ppdupswap(2, "2121"); break;
1497 case Bytecodes::_dup2_x1: ppdupswap(3, "21321"); break;
1498 case Bytecodes::_dup2_x2: ppdupswap(4, "214321"); break;
1499 case Bytecodes::_swap: ppdupswap(2, "12"); break;
1500
1501 case Bytecodes::_iadd:
1502 case Bytecodes::_fadd:
1503 case Bytecodes::_isub:
1504 case Bytecodes::_fsub:
1505 case Bytecodes::_imul:
1506 case Bytecodes::_fmul:
1507 case Bytecodes::_idiv:
1508 case Bytecodes::_fdiv:
1509 case Bytecodes::_irem:
1510 case Bytecodes::_frem:
1511 case Bytecodes::_ishl:
1512 case Bytecodes::_ishr:
1513 case Bytecodes::_iushr:
1514 case Bytecodes::_iand:
1515 case Bytecodes::_ior:
1516 case Bytecodes::_ixor:
1517 case Bytecodes::_l2f:
1518 case Bytecodes::_l2i:
1519 case Bytecodes::_d2f:
1520 case Bytecodes::_d2i:
1521 case Bytecodes::_fcmpl:
1522 case Bytecodes::_fcmpg: pp(vvCTS, vCTS); break;
1523
1524 case Bytecodes::_ladd:
1525 case Bytecodes::_dadd:
1526 case Bytecodes::_lsub:
1527 case Bytecodes::_dsub:
1528 case Bytecodes::_lmul:
1529 case Bytecodes::_dmul:
1530 case Bytecodes::_ldiv:
1531 case Bytecodes::_ddiv:
1532 case Bytecodes::_lrem:
1533 case Bytecodes::_drem:
1534 case Bytecodes::_land:
1535 case Bytecodes::_lor:
1536 case Bytecodes::_lxor: pp(vvvvCTS, vvCTS); break;
1537
1538 case Bytecodes::_ineg:
1539 case Bytecodes::_fneg:
1540 case Bytecodes::_i2f:
1541 case Bytecodes::_f2i:
1542 case Bytecodes::_i2c:
1543 case Bytecodes::_i2s:
1544 case Bytecodes::_i2b: pp(vCTS, vCTS); break;
1545
1546 case Bytecodes::_lneg:
1547 case Bytecodes::_dneg:
1548 case Bytecodes::_l2d:
1549 case Bytecodes::_d2l: pp(vvCTS, vvCTS); break;
1550
1551 case Bytecodes::_lshl:
1552 case Bytecodes::_lshr:
1553 case Bytecodes::_lushr: pp(vvvCTS, vvCTS); break;
1554
1555 case Bytecodes::_i2l:
1556 case Bytecodes::_i2d:
1557 case Bytecodes::_f2l:
1558 case Bytecodes::_f2d: pp(vCTS, vvCTS); break;
1559
1560 case Bytecodes::_lcmp: pp(vvvvCTS, vCTS); break;
1561 case Bytecodes::_dcmpl:
1562 case Bytecodes::_dcmpg: pp(vvvvCTS, vCTS); break;
1563
1564 case Bytecodes::_ifeq:
1565 case Bytecodes::_ifne:
1566 case Bytecodes::_iflt:
1567 case Bytecodes::_ifge:
1568 case Bytecodes::_ifgt:
1569 case Bytecodes::_ifle:
1570 case Bytecodes::_tableswitch: ppop1(valCTS);
1571 break;
1572 case Bytecodes::_ireturn:
1573 case Bytecodes::_freturn: do_return_monitor_check();
1574 ppop1(valCTS);
1575 break;
1576 case Bytecodes::_if_icmpeq:
1577 case Bytecodes::_if_icmpne:
1578 case Bytecodes::_if_icmplt:
1579 case Bytecodes::_if_icmpge:
1580 case Bytecodes::_if_icmpgt:
1581 case Bytecodes::_if_icmple: ppop(vvCTS);
1582 break;
1583
1584 case Bytecodes::_lreturn: do_return_monitor_check();
1585 ppop(vvCTS);
1586 break;
1587
1588 case Bytecodes::_dreturn: do_return_monitor_check();
1589 ppop(vvCTS);
1590 break;
1591
1592 case Bytecodes::_if_acmpeq:
1593 case Bytecodes::_if_acmpne: ppop(rrCTS); break;
1594
1595 case Bytecodes::_jsr: do_jsr(itr->dest()); break;
1596 case Bytecodes::_jsr_w: do_jsr(itr->dest_w()); break;
1597
1598 case Bytecodes::_getstatic: do_field(true, true, itr->get_index_u2_cpcache(), itr->bci()); break;
1599 case Bytecodes::_putstatic: do_field(false, true, itr->get_index_u2_cpcache(), itr->bci()); break;
1600 case Bytecodes::_getfield: do_field(true, false, itr->get_index_u2_cpcache(), itr->bci()); break;
1601 case Bytecodes::_putfield: do_field(false, false, itr->get_index_u2_cpcache(), itr->bci()); break;
1602
1603 case Bytecodes::_invokeinterface:
1604 case Bytecodes::_invokevirtual:
1605 case Bytecodes::_invokespecial: do_method(false, itr->get_index_u2_cpcache(), itr->bci()); break;
1606 case Bytecodes::_invokestatic: do_method(true , itr->get_index_u2_cpcache(), itr->bci()); break;
1607 case Bytecodes::_invokedynamic: do_method(true , itr->get_index_u4(), itr->bci()); break;
1608 case Bytecodes::_newarray:
1609 case Bytecodes::_anewarray: pp_new_ref(vCTS, itr->bci()); break;
1610 case Bytecodes::_checkcast: do_checkcast(); break;
1611 case Bytecodes::_arraylength:
1612 case Bytecodes::_instanceof: pp(rCTS, vCTS); break;
1613 case Bytecodes::_monitorenter: do_monitorenter(itr->bci()); break;
1614 case Bytecodes::_monitorexit: do_monitorexit(itr->bci()); break;
1615
1616 case Bytecodes::_athrow: // handled by do_exception_edge() BUT ...
1617 // vlh(apple): do_exception_edge() does not get
1618 // called if method has no exception handlers
1619 if ((!_has_exceptions) && (_monitor_top > 0)) {
1620 _monitor_safe = false;
1621 }
1622 break;
1623
1624 case Bytecodes::_areturn: do_return_monitor_check();
1625 ppop1(refCTS);
1626 break;
1627
1628 case Bytecodes::_ifnull:
1629 case Bytecodes::_ifnonnull: ppop1(refCTS); break;
1630 case Bytecodes::_multianewarray: do_multianewarray(*(itr->bcp()+3), itr->bci()); break;
1631
1632 case Bytecodes::_wide: fatal("Iterator should skip this bytecode"); break;
1633 case Bytecodes::_ret: break;
1634
1635 // Java opcodes
1636 case Bytecodes::_lookupswitch: ppop1(valCTS); break;
1637
1638 default:
1639 tty->print("unexpected opcode: %d\n", itr->code());
1640 ShouldNotReachHere();
1641 break;
1642 }
1643 }
1644
1645 void GenerateOopMap::check_type(CellTypeState expected, CellTypeState actual) {
1646 if (!expected.equal_kind(actual)) {
1647 verify_error("wrong type on stack (found: %c expected: %c)", actual.to_char(), expected.to_char());
1648 }
1649 }
1650
1651 void GenerateOopMap::ppstore(CellTypeState *in, int loc_no) {
1652 while(!(*in).is_bottom()) {
1653 CellTypeState expected =*in++;
1654 CellTypeState actual = pop();
1655 check_type(expected, actual);
1656 assert(loc_no >= 0, "sanity check");
1657 set_var(loc_no++, actual);
1658 }
1659 }
1660
1661 void GenerateOopMap::ppload(CellTypeState *out, int loc_no) {
1662 while(!(*out).is_bottom()) {
1663 CellTypeState out1 = *out++;
1664 CellTypeState vcts = get_var(loc_no);
1665 assert(out1.can_be_reference() || out1.can_be_value(),
1666 "can only load refs. and values.");
1667 if (out1.is_reference()) {
1668 assert(loc_no>=0, "sanity check");
1669 if (!vcts.is_reference()) {
1670 // We were asked to push a reference, but the type of the
1671 // variable can be something else
1672 _conflict = true;
1673 if (vcts.can_be_uninit()) {
1674 // It is a ref-uninit conflict (at least). If there are other
1675 // problems, we'll get them in the next round
1676 add_to_ref_init_set(loc_no);
1677 vcts = out1;
1678 } else {
1679 // It wasn't a ref-uninit conflict. So must be a
1680 // ref-val or ref-pc conflict. Split the variable.
1681 record_refval_conflict(loc_no);
1682 vcts = out1;
1683 }
1684 push(out1); // recover...
1685 } else {
1686 push(vcts); // preserve reference.
1687 }
1688 // Otherwise it is a conflict, but one that verification would
1689 // have caught if illegal. In particular, it can't be a topCTS
1690 // resulting from mergeing two difference pcCTS's since the verifier
1691 // would have rejected any use of such a merge.
1692 } else {
1693 push(out1); // handle val/init conflict
1694 }
1695 loc_no++;
1696 }
1697 }
1698
1699 void GenerateOopMap::ppdupswap(int poplen, const char *out) {
1700 CellTypeState actual[5];
1701 assert(poplen < 5, "this must be less than length of actual vector");
1702
1703 // Pop all arguments.
1704 for (int i = 0; i < poplen; i++) {
1705 actual[i] = pop();
1706 }
1707 // Field _state is uninitialized when calling push.
1708 for (int i = poplen; i < 5; i++) {
1709 actual[i] = CellTypeState::uninit;
1710 }
1711
1712 // put them back
1713 char push_ch = *out++;
1714 while (push_ch != '\0') {
1715 int idx = push_ch - '1';
1716 assert(idx >= 0 && idx < poplen, "wrong arguments");
1717 push(actual[idx]);
1718 push_ch = *out++;
1719 }
1720 }
1721
1722 void GenerateOopMap::ppop1(CellTypeState out) {
1723 CellTypeState actual = pop();
1724 check_type(out, actual);
1725 }
1726
1727 void GenerateOopMap::ppop(CellTypeState *out) {
1728 while (!(*out).is_bottom()) {
1729 ppop1(*out++);
1730 }
1731 }
1732
1733 void GenerateOopMap::ppush1(CellTypeState in) {
1734 assert(in.is_reference() || in.is_value(), "sanity check");
1735 push(in);
1736 }
1737
1738 void GenerateOopMap::ppush(CellTypeState *in) {
1739 while (!(*in).is_bottom()) {
1740 ppush1(*in++);
1741 }
1742 }
1743
1744 void GenerateOopMap::pp(CellTypeState *in, CellTypeState *out) {
1745 ppop(in);
1746 ppush(out);
1747 }
1748
1749 void GenerateOopMap::pp_new_ref(CellTypeState *in, int bci) {
1750 ppop(in);
1751 ppush1(CellTypeState::make_line_ref(bci));
1752 }
1753
1754 void GenerateOopMap::ppop_any(int poplen) {
1755 if (_stack_top >= poplen) {
1756 _stack_top -= poplen;
1757 } else {
1758 verify_error("stack underflow");
1759 }
1760 }
1761
1762 // Replace all occurences of the state 'match' with the state 'replace'
1763 // in our current state vector.
1764 void GenerateOopMap::replace_all_CTS_matches(CellTypeState match,
1765 CellTypeState replace) {
1766 int i;
1767 int len = _max_locals + _stack_top;
1768 bool change = false;
1769
1770 for (i = len - 1; i >= 0; i--) {
1771 if (match.equal(_state[i])) {
1772 _state[i] = replace;
1773 }
1774 }
1775
1776 if (_monitor_top > 0) {
1777 int base = _max_locals + _max_stack;
1778 len = base + _monitor_top;
1779 for (i = len - 1; i >= base; i--) {
1780 if (match.equal(_state[i])) {
1781 _state[i] = replace;
1782 }
1783 }
1784 }
1785 }
1786
1787 void GenerateOopMap::do_checkcast() {
1788 CellTypeState actual = pop();
1789 check_type(refCTS, actual);
1790 push(actual);
1791 }
1792
1793 void GenerateOopMap::do_monitorenter(int bci) {
1794 CellTypeState actual = pop();
1795 if (_monitor_top == bad_monitors) {
1796 return;
1797 }
1798
1799 // Bail out when we get repeated locks on an identical monitor. This case
1800 // isn't too hard to handle and can be made to work if supporting nested
1801 // redundant synchronized statements becomes a priority.
1802 //
1803 // See also "Note" in do_monitorexit(), below.
1804 if (actual.is_lock_reference()) {
1805 _monitor_top = bad_monitors;
1806 _monitor_safe = false;
1807
1808 if (log_is_enabled(Info, monitormismatch)) {
1809 report_monitor_mismatch("nested redundant lock -- bailout...");
1810 }
1811 return;
1812 }
1813
1814 CellTypeState lock = CellTypeState::make_lock_ref(bci);
1815 check_type(refCTS, actual);
1816 if (!actual.is_info_top()) {
1817 replace_all_CTS_matches(actual, lock);
1818 monitor_push(lock);
1819 }
1820 }
1821
1822 void GenerateOopMap::do_monitorexit(int bci) {
1823 CellTypeState actual = pop();
1824 if (_monitor_top == bad_monitors) {
1825 return;
1826 }
1827 check_type(refCTS, actual);
1828 CellTypeState expected = monitor_pop();
1829 if (!actual.is_lock_reference() || !expected.equal(actual)) {
1830 // The monitor we are exiting is not verifiably the one
1831 // on the top of our monitor stack. This causes a monitor
1832 // mismatch.
1833 _monitor_top = bad_monitors;
1834 _monitor_safe = false;
1835
1836 // We need to mark this basic block as changed so that
1837 // this monitorexit will be visited again. We need to
1838 // do this to ensure that we have accounted for the
1839 // possibility that this bytecode will throw an
1840 // exception.
1841 BasicBlock* bb = get_basic_block_containing(bci);
1842 guarantee(bb != NULL, "no basic block for bci");
1843 bb->set_changed(true);
1844 bb->_monitor_top = bad_monitors;
1845
1846 if (log_is_enabled(Info, monitormismatch)) {
1847 report_monitor_mismatch("improper monitor pair");
1848 }
1849 } else {
1850 // This code is a fix for the case where we have repeated
1851 // locking of the same object in straightline code. We clear
1852 // out the lock when it is popped from the monitor stack
1853 // and replace it with an unobtrusive reference value that can
1854 // be locked again.
1855 //
1856 // Note: when generateOopMap is fixed to properly handle repeated,
1857 // nested, redundant locks on the same object, then this
1858 // fix will need to be removed at that time.
1859 replace_all_CTS_matches(actual, CellTypeState::make_line_ref(bci));
1860 }
1861 }
1862
1863 void GenerateOopMap::do_return_monitor_check() {
1864 if (_monitor_top > 0) {
1865 // The monitor stack must be empty when we leave the method
1866 // for the monitors to be properly matched.
1867 _monitor_safe = false;
1868
1869 // Since there are no successors to the *return bytecode, it
1870 // isn't necessary to set _monitor_top to bad_monitors.
1871
1872 if (log_is_enabled(Info, monitormismatch)) {
1873 report_monitor_mismatch("non-empty monitor stack at return");
1874 }
1875 }
1876 }
1877
1878 void GenerateOopMap::do_jsr(int targ_bci) {
1879 push(CellTypeState::make_addr(targ_bci));
1880 }
1881
1882
1883
1884 void GenerateOopMap::do_ldc(int bci) {
1885 Bytecode_loadconstant ldc(method(), bci);
1886 ConstantPool* cp = method()->constants();
1887 constantTag tag = cp->tag_at(ldc.pool_index()); // idx is index in resolved_references
1888 BasicType bt = ldc.result_type();
1889 #ifdef ASSERT
1890 BasicType tag_bt = (tag.is_dynamic_constant() || tag.is_dynamic_constant_in_error()) ? bt : tag.basic_type();
1891 assert(bt == tag_bt, "same result");
1892 #endif
1893 CellTypeState cts;
1894 if (is_reference_type(bt)) { // could be T_ARRAY with condy
1895 assert(!tag.is_string_index() && !tag.is_klass_index(), "Unexpected index tag");
1896 cts = CellTypeState::make_line_ref(bci);
1897 } else {
1898 cts = valCTS;
1899 }
1900 ppush1(cts);
1901 }
1902
1903 void GenerateOopMap::do_multianewarray(int dims, int bci) {
1904 assert(dims >= 1, "sanity check");
1905 for(int i = dims -1; i >=0; i--) {
1906 ppop1(valCTS);
1907 }
1908 ppush1(CellTypeState::make_line_ref(bci));
1909 }
1910
1911 void GenerateOopMap::do_astore(int idx) {
1912 CellTypeState r_or_p = pop();
1913 if (!r_or_p.is_address() && !r_or_p.is_reference()) {
1914 // We actually expected ref or pc, but we only report that we expected a ref. It does not
1915 // really matter (at least for now)
1916 verify_error("wrong type on stack (found: %c, expected: {pr})", r_or_p.to_char());
1917 return;
1918 }
1919 set_var(idx, r_or_p);
1920 }
1921
1922 // Copies bottom/zero terminated CTS string from "src" into "dst".
1923 // Does NOT terminate with a bottom. Returns the number of cells copied.
1924 int GenerateOopMap::copy_cts(CellTypeState *dst, CellTypeState *src) {
1925 int idx = 0;
1926 while (!src[idx].is_bottom()) {
1927 dst[idx] = src[idx];
1928 idx++;
1929 }
1930 return idx;
1931 }
1932
1933 void GenerateOopMap::do_field(int is_get, int is_static, int idx, int bci) {
1934 // Dig up signature for field in constant pool
1935 ConstantPool* cp = method()->constants();
1936 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
1937 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1938 Symbol* signature = cp->symbol_at(signatureIdx);
1939
1940 // Parse signature (espcially simple for fields)
1941 assert(signature->utf8_length() > 0, "field signatures cannot have zero length");
1942 // The signature is UFT8 encoded, but the first char is always ASCII for signatures.
1943 char sigch = (char)*(signature->base());
1944 CellTypeState temp[4];
1945 CellTypeState *eff = sigchar_to_effect(sigch, bci, temp);
1946
1947 CellTypeState in[4];
1948 CellTypeState *out;
1949 int i = 0;
1950
1951 if (is_get) {
1952 out = eff;
1953 } else {
1954 out = epsilonCTS;
1955 i = copy_cts(in, eff);
1956 }
1957 if (!is_static) {
1958 in[i++] = CellTypeState::ref;
1959 }
1960 in[i] = CellTypeState::bottom;
1961 assert(i<=3, "sanity check");
1962 pp(in, out);
1963 }
1964
1965 void GenerateOopMap::do_method(int is_static, int idx, int bci) {
1966 // Dig up signature for field in constant pool
1967 ConstantPool* cp = _method->constants();
1968 Symbol* signature = cp->signature_ref_at(idx);
1969
1970 // Parse method signature
1971 CellTypeState out[4];
1972 CellTypeState in[MAXARGSIZE+1]; // Includes result
1973 ComputeCallStack cse(signature);
1974
1975 // Compute return type
1976 int res_length= cse.compute_for_returntype(out);
1977
1978 // Temporary hack.
1979 if (out[0].equal(CellTypeState::ref) && out[1].equal(CellTypeState::bottom)) {
1980 out[0] = CellTypeState::make_line_ref(bci);
1981 }
1982
1983 assert(res_length<=4, "max value should be vv");
1984
1985 // Compute arguments
1986 int arg_length = cse.compute_for_parameters(is_static != 0, in);
1987 assert(arg_length<=MAXARGSIZE, "too many locals");
1988
1989 // Pop arguments
1990 for (int i = arg_length - 1; i >= 0; i--) ppop1(in[i]);// Do args in reverse order.
1991
1992 // Report results
1993 if (_report_result_for_send == true) {
1994 fill_stackmap_for_opcodes(_itr_send, vars(), stack(), _stack_top);
1995 _report_result_for_send = false;
1996 }
1997
1998 // Push return address
1999 ppush(out);
2000 }
2001
2002 void GenerateOopMap::do_withfield(int idx, int bci) {
2003 // Dig up signature for field in constant pool
2004 ConstantPool* cp = method()->constants();
2005 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
2006 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
2007 Symbol* signature = cp->symbol_at(signatureIdx);
2008
2009 // Parse signature (especially simple for fields)
2010 assert(signature->utf8_length() > 0,
2011 "field signatures cannot have zero length");
2012 // The signature is UFT8 encoded, but the first char is always ASCII for signatures.
2013 char sigch = (char) *(signature->base());
2014 CellTypeState temp[4];
2015 CellTypeState *eff = sigchar_to_effect(sigch, bci, temp);
2016
2017 CellTypeState in[4];
2018 int i = copy_cts(in, eff);
2019 in[i++] = CellTypeState::ref;
2020 in[i] = CellTypeState::bottom;
2021 assert(i <= 3, "sanity check");
2022
2023 CellTypeState out[2];
2024 out[0] = CellTypeState::ref;
2025 out[1] = CellTypeState::bottom;
2026
2027 pp(in, out);
2028 }
2029
2030 // This is used to parse the signature for fields, since they are very simple...
2031 CellTypeState *GenerateOopMap::sigchar_to_effect(char sigch, int bci, CellTypeState *out) {
2032 // Object and array
2033 if (sigch=='L' || sigch=='[' || sigch=='Q') {
2034 out[0] = CellTypeState::make_line_ref(bci);
2035 out[1] = CellTypeState::bottom;
2036 return out;
2037 }
2038 if (sigch == 'J' || sigch == 'D' ) return vvCTS; // Long and Double
2039 if (sigch == 'V' ) return epsilonCTS; // Void
2040 return vCTS; // Otherwise
2041 }
2042
2043 long GenerateOopMap::_total_byte_count = 0;
2044 elapsedTimer GenerateOopMap::_total_oopmap_time;
2045
2046 // This function assumes "bcs" is at a "ret" instruction and that the vars
2047 // state is valid for that instruction. Furthermore, the ret instruction
2048 // must be the last instruction in "bb" (we store information about the
2049 // "ret" in "bb").
2050 void GenerateOopMap::ret_jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int varNo, int *data) {
2051 CellTypeState ra = vars()[varNo];
2052 if (!ra.is_good_address()) {
2053 verify_error("ret returns from two jsr subroutines?");
2054 return;
2055 }
2056 int target = ra.get_info();
2057
2058 RetTableEntry* rtEnt = _rt.find_jsrs_for_target(target);
2059 int bci = bcs->bci();
2060 for (int i = 0; i < rtEnt->nof_jsrs(); i++) {
2061 int target_bci = rtEnt->jsrs(i);
2062 // Make sure a jrtRet does not set the changed bit for dead basicblock.
2063 BasicBlock* jsr_bb = get_basic_block_containing(target_bci - 1);
2064 debug_only(BasicBlock* target_bb = &jsr_bb[1];)
2065 assert(target_bb == get_basic_block_at(target_bci), "wrong calc. of successor basicblock");
2066 bool alive = jsr_bb->is_alive();
2067 if (TraceNewOopMapGeneration) {
2068 tty->print("pc = %d, ret -> %d alive: %s\n", bci, target_bci, alive ? "true" : "false");
2069 }
2070 if (alive) jmpFct(this, target_bci, data);
2071 }
2072 }
2073
2074 //
2075 // Debug method
2076 //
2077 char* GenerateOopMap::state_vec_to_string(CellTypeState* vec, int len) {
2078 #ifdef ASSERT
2079 int checklen = MAX3(_max_locals, _max_stack, _max_monitors) + 1;
2080 assert(len < checklen, "state_vec_buf overflow");
2081 #endif
2082 for (int i = 0; i < len; i++) _state_vec_buf[i] = vec[i].to_char();
2083 _state_vec_buf[len] = 0;
2084 return _state_vec_buf;
2085 }
2086
2087 void GenerateOopMap::print_time() {
2088 tty->print_cr ("Accumulated oopmap times:");
2089 tty->print_cr ("---------------------------");
2090 tty->print_cr (" Total : %3.3f sec.", GenerateOopMap::_total_oopmap_time.seconds());
2091 tty->print_cr (" (%3.0f bytecodes per sec) ",
2092 GenerateOopMap::_total_byte_count / GenerateOopMap::_total_oopmap_time.seconds());
2093 }
2094
2095 //
2096 // ============ Main Entry Point ===========
2097 //
2098 GenerateOopMap::GenerateOopMap(const methodHandle& method) {
2099 // We have to initialize all variables here, that can be queried directly
2100 _method = method;
2101 _max_locals=0;
2102 _init_vars = NULL;
2103
2104 #ifndef PRODUCT
2105 // If we are doing a detailed trace, include the regular trace information.
2106 if (TraceNewOopMapGenerationDetailed) {
2107 TraceNewOopMapGeneration = true;
2108 }
2109 #endif
2110 }
2111
2112 void GenerateOopMap::compute_map(TRAPS) {
2113 #ifndef PRODUCT
2114 if (TimeOopMap2) {
2115 method()->print_short_name(tty);
2116 tty->print(" ");
2117 }
2118 if (TimeOopMap) {
2119 _total_byte_count += method()->code_size();
2120 }
2121 #endif
2122 TraceTime t_single("oopmap time", TimeOopMap2);
2123 TraceTime t_all(NULL, &_total_oopmap_time, TimeOopMap);
2124
2125 // Initialize values
2126 _got_error = false;
2127 _conflict = false;
2128 _max_locals = method()->max_locals();
2129 _max_stack = method()->max_stack();
2130 _has_exceptions = (method()->has_exception_handler());
2131 _nof_refval_conflicts = 0;
2132 _init_vars = new GrowableArray<intptr_t>(5); // There are seldom more than 5 init_vars
2133 _report_result = false;
2134 _report_result_for_send = false;
2135 _new_var_map = NULL;
2136 _ret_adr_tos = new GrowableArray<intptr_t>(5); // 5 seems like a good number;
2137 _did_rewriting = false;
2138 _did_relocation = false;
2139
2140 if (TraceNewOopMapGeneration) {
2141 tty->print("Method name: %s\n", method()->name()->as_C_string());
2142 if (Verbose) {
2143 _method->print_codes();
2144 tty->print_cr("Exception table:");
2145 ExceptionTable excps(method());
2146 for(int i = 0; i < excps.length(); i ++) {
2147 tty->print_cr("[%d - %d] -> %d",
2148 excps.start_pc(i), excps.end_pc(i), excps.handler_pc(i));
2149 }
2150 }
2151 }
2152
2153 // if no code - do nothing
2154 // compiler needs info
2155 if (method()->code_size() == 0 || _max_locals + method()->max_stack() == 0) {
2156 fill_stackmap_prolog(0);
2157 fill_stackmap_epilog();
2158 return;
2159 }
2160 // Step 1: Compute all jump targets and their return value
2161 if (!_got_error)
2162 _rt.compute_ret_table(_method);
2163
2164 // Step 2: Find all basic blocks and count GC points
2165 if (!_got_error)
2166 mark_bbheaders_and_count_gc_points();
2167
2168 // Step 3: Calculate stack maps
2169 if (!_got_error)
2170 do_interpretation();
2171
2172 // Step 4:Return results
2173 if (!_got_error && report_results())
2174 report_result();
2175
2176 if (_got_error) {
2177 THROW_HANDLE(_exception);
2178 }
2179 }
2180
2181 // Error handling methods
2182 // These methods create an exception for the current thread which is thrown
2183 // at the bottom of the call stack, when it returns to compute_map(). The
2184 // _got_error flag controls execution. NOT TODO: The VM exception propagation
2185 // mechanism using TRAPS/CHECKs could be used here instead but it would need
2186 // to be added as a parameter to every function and checked for every call.
2187 // The tons of extra code it would generate didn't seem worth the change.
2188 //
2189 void GenerateOopMap::error_work(const char *format, va_list ap) {
2190 _got_error = true;
2191 char msg_buffer[512];
2192 os::vsnprintf(msg_buffer, sizeof(msg_buffer), format, ap);
2193 // Append method name
2194 char msg_buffer2[512];
2195 os::snprintf(msg_buffer2, sizeof(msg_buffer2), "%s in method %s", msg_buffer, method()->name()->as_C_string());
2196 if (Thread::current()->can_call_java()) {
2197 _exception = Exceptions::new_exception(Thread::current(),
2198 vmSymbols::java_lang_LinkageError(), msg_buffer2);
2199 } else {
2200 // We cannot instantiate an exception object from a compiler thread.
2201 // Exit the VM with a useful error message.
2202 fatal("%s", msg_buffer2);
2203 }
2204 }
2205
2206 void GenerateOopMap::report_error(const char *format, ...) {
2207 va_list ap;
2208 va_start(ap, format);
2209 error_work(format, ap);
2210 }
2211
2212 void GenerateOopMap::verify_error(const char *format, ...) {
2213 // We do not distinguish between different types of errors for verification
2214 // errors. Let the verifier give a better message.
2215 report_error("Illegal class file encountered. Try running with -Xverify:all");
2216 }
2217
2218 //
2219 // Report result opcodes
2220 //
2221 void GenerateOopMap::report_result() {
2222
2223 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass");
2224
2225 // We now want to report the result of the parse
2226 _report_result = true;
2227
2228 // Prolog code
2229 fill_stackmap_prolog(_gc_points);
2230
2231 // Mark everything changed, then do one interpretation pass.
2232 for (int i = 0; i<_bb_count; i++) {
2233 if (_basic_blocks[i].is_reachable()) {
2234 _basic_blocks[i].set_changed(true);
2235 interp_bb(&_basic_blocks[i]);
2236 }
2237 }
2238
2239 // Note: Since we are skipping dead-code when we are reporting results, then
2240 // the no. of encountered gc-points might be fewer than the previously number
2241 // we have counted. (dead-code is a pain - it should be removed before we get here)
2242 fill_stackmap_epilog();
2243
2244 // Report initvars
2245 fill_init_vars(_init_vars);
2246
2247 _report_result = false;
2248 }
2249
2250 void GenerateOopMap::result_for_basicblock(int bci) {
2251 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass for basicblock");
2252
2253 // We now want to report the result of the parse
2254 _report_result = true;
2255
2256 // Find basicblock and report results
2257 BasicBlock* bb = get_basic_block_containing(bci);
2258 guarantee(bb != NULL, "no basic block for bci");
2259 assert(bb->is_reachable(), "getting result from unreachable basicblock");
2260 bb->set_changed(true);
2261 interp_bb(bb);
2262 }
2263
2264 //
2265 // Conflict handling code
2266 //
2267
2268 void GenerateOopMap::record_refval_conflict(int varNo) {
2269 assert(varNo>=0 && varNo< _max_locals, "index out of range");
2270
2271 if (TraceOopMapRewrites) {
2272 tty->print("### Conflict detected (local no: %d)\n", varNo);
2273 }
2274
2275 if (!_new_var_map) {
2276 _new_var_map = NEW_RESOURCE_ARRAY(int, _max_locals);
2277 for (int k = 0; k < _max_locals; k++) _new_var_map[k] = k;
2278 }
2279
2280 if ( _new_var_map[varNo] == varNo) {
2281 // Check if max. number of locals has been reached
2282 if (_max_locals + _nof_refval_conflicts >= MAX_LOCAL_VARS) {
2283 report_error("Rewriting exceeded local variable limit");
2284 return;
2285 }
2286 _new_var_map[varNo] = _max_locals + _nof_refval_conflicts;
2287 _nof_refval_conflicts++;
2288 }
2289 }
2290
2291 void GenerateOopMap::rewrite_refval_conflicts()
2292 {
2293 // We can get here two ways: Either a rewrite conflict was detected, or
2294 // an uninitialize reference was detected. In the second case, we do not
2295 // do any rewriting, we just want to recompute the reference set with the
2296 // new information
2297
2298 int nof_conflicts = 0; // Used for debugging only
2299
2300 if ( _nof_refval_conflicts == 0 )
2301 return;
2302
2303 // Check if rewrites are allowed in this parse.
2304 if (!allow_rewrites() && !IgnoreRewrites) {
2305 fatal("Rewriting method not allowed at this stage");
2306 }
2307
2308
2309 // This following flag is to tempoary supress rewrites. The locals that might conflict will
2310 // all be set to contain values. This is UNSAFE - however, until the rewriting has been completely
2311 // tested it is nice to have.
2312 if (IgnoreRewrites) {
2313 if (Verbose) {
2314 tty->print("rewrites suppressed for local no. ");
2315 for (int l = 0; l < _max_locals; l++) {
2316 if (_new_var_map[l] != l) {
2317 tty->print("%d ", l);
2318 vars()[l] = CellTypeState::value;
2319 }
2320 }
2321 tty->cr();
2322 }
2323
2324 // That was that...
2325 _new_var_map = NULL;
2326 _nof_refval_conflicts = 0;
2327 _conflict = false;
2328
2329 return;
2330 }
2331
2332 // Tracing flag
2333 _did_rewriting = true;
2334
2335 if (TraceOopMapRewrites) {
2336 tty->print_cr("ref/value conflict for method %s - bytecodes are getting rewritten", method()->name()->as_C_string());
2337 method()->print();
2338 method()->print_codes();
2339 }
2340
2341 assert(_new_var_map!=NULL, "nothing to rewrite");
2342 assert(_conflict==true, "We should not be here");
2343
2344 compute_ret_adr_at_TOS();
2345 if (!_got_error) {
2346 for (int k = 0; k < _max_locals && !_got_error; k++) {
2347 if (_new_var_map[k] != k) {
2348 if (TraceOopMapRewrites) {
2349 tty->print_cr("Rewriting: %d -> %d", k, _new_var_map[k]);
2350 }
2351 rewrite_refval_conflict(k, _new_var_map[k]);
2352 if (_got_error) return;
2353 nof_conflicts++;
2354 }
2355 }
2356 }
2357
2358 assert(nof_conflicts == _nof_refval_conflicts, "sanity check");
2359
2360 // Adjust the number of locals
2361 method()->set_max_locals(_max_locals+_nof_refval_conflicts);
2362 _max_locals += _nof_refval_conflicts;
2363
2364 // That was that...
2365 _new_var_map = NULL;
2366 _nof_refval_conflicts = 0;
2367 }
2368
2369 void GenerateOopMap::rewrite_refval_conflict(int from, int to) {
2370 bool startOver;
2371 do {
2372 // Make sure that the BytecodeStream is constructed in the loop, since
2373 // during rewriting a new method oop is going to be used, and the next time
2374 // around we want to use that.
2375 BytecodeStream bcs(_method);
2376 startOver = false;
2377
2378 while( !startOver && !_got_error &&
2379 // test bcs in case method changed and it became invalid
2380 bcs.next() >=0) {
2381 startOver = rewrite_refval_conflict_inst(&bcs, from, to);
2382 }
2383 } while (startOver && !_got_error);
2384 }
2385
2386 /* If the current instruction is one that uses local variable "from"
2387 in a ref way, change it to use "to". There's a subtle reason why we
2388 renumber the ref uses and not the non-ref uses: non-ref uses may be
2389 2 slots wide (double, long) which would necessitate keeping track of
2390 whether we should add one or two variables to the method. If the change
2391 affected the width of some instruction, returns "TRUE"; otherwise, returns "FALSE".
2392 Another reason for moving ref's value is for solving (addr, ref) conflicts, which
2393 both uses aload/astore methods.
2394 */
2395 bool GenerateOopMap::rewrite_refval_conflict_inst(BytecodeStream *itr, int from, int to) {
2396 Bytecodes::Code bc = itr->code();
2397 int index;
2398 int bci = itr->bci();
2399
2400 if (is_aload(itr, &index) && index == from) {
2401 if (TraceOopMapRewrites) {
2402 tty->print_cr("Rewriting aload at bci: %d", bci);
2403 }
2404 return rewrite_load_or_store(itr, Bytecodes::_aload, Bytecodes::_aload_0, to);
2405 }
2406
2407 if (is_astore(itr, &index) && index == from) {
2408 if (!stack_top_holds_ret_addr(bci)) {
2409 if (TraceOopMapRewrites) {
2410 tty->print_cr("Rewriting astore at bci: %d", bci);
2411 }
2412 return rewrite_load_or_store(itr, Bytecodes::_astore, Bytecodes::_astore_0, to);
2413 } else {
2414 if (TraceOopMapRewrites) {
2415 tty->print_cr("Supress rewriting of astore at bci: %d", bci);
2416 }
2417 }
2418 }
2419
2420 return false;
2421 }
2422
2423 // The argument to this method is:
2424 // bc : Current bytecode
2425 // bcN : either _aload or _astore
2426 // bc0 : either _aload_0 or _astore_0
2427 bool GenerateOopMap::rewrite_load_or_store(BytecodeStream *bcs, Bytecodes::Code bcN, Bytecodes::Code bc0, unsigned int varNo) {
2428 assert(bcN == Bytecodes::_astore || bcN == Bytecodes::_aload, "wrong argument (bcN)");
2429 assert(bc0 == Bytecodes::_astore_0 || bc0 == Bytecodes::_aload_0, "wrong argument (bc0)");
2430 int ilen = Bytecodes::length_at(_method(), bcs->bcp());
2431 int newIlen;
2432
2433 if (ilen == 4) {
2434 // Original instruction was wide; keep it wide for simplicity
2435 newIlen = 4;
2436 } else if (varNo < 4)
2437 newIlen = 1;
2438 else if (varNo >= 256)
2439 newIlen = 4;
2440 else
2441 newIlen = 2;
2442
2443 // If we need to relocate in order to patch the byte, we
2444 // do the patching in a temp. buffer, that is passed to the reloc.
2445 // The patching of the bytecode stream is then done by the Relocator.
2446 // This is neccesary, since relocating the instruction at a certain bci, might
2447 // also relocate that instruction, e.g., if a _goto before it gets widen to a _goto_w.
2448 // Hence, we do not know which bci to patch after relocation.
2449
2450 assert(newIlen <= 4, "sanity check");
2451 u_char inst_buffer[4]; // Max. instruction size is 4.
2452 address bcp;
2453
2454 if (newIlen != ilen) {
2455 // Relocation needed do patching in temp. buffer
2456 bcp = (address)inst_buffer;
2457 } else {
2458 bcp = _method->bcp_from(bcs->bci());
2459 }
2460
2461 // Patch either directly in Method* or in temp. buffer
2462 if (newIlen == 1) {
2463 assert(varNo < 4, "varNo too large");
2464 *bcp = bc0 + varNo;
2465 } else if (newIlen == 2) {
2466 assert(varNo < 256, "2-byte index needed!");
2467 *(bcp + 0) = bcN;
2468 *(bcp + 1) = varNo;
2469 } else {
2470 assert(newIlen == 4, "Wrong instruction length");
2471 *(bcp + 0) = Bytecodes::_wide;
2472 *(bcp + 1) = bcN;
2473 Bytes::put_Java_u2(bcp+2, varNo);
2474 }
2475
2476 if (newIlen != ilen) {
2477 expand_current_instr(bcs->bci(), ilen, newIlen, inst_buffer);
2478 }
2479
2480
2481 return (newIlen != ilen);
2482 }
2483
2484 class RelocCallback : public RelocatorListener {
2485 private:
2486 GenerateOopMap* _gom;
2487 public:
2488 RelocCallback(GenerateOopMap* gom) { _gom = gom; };
2489
2490 // Callback method
2491 virtual void relocated(int bci, int delta, int new_code_length) {
2492 _gom->update_basic_blocks (bci, delta, new_code_length);
2493 _gom->update_ret_adr_at_TOS(bci, delta);
2494 _gom->_rt.update_ret_table (bci, delta);
2495 }
2496 };
2497
2498 // Returns true if expanding was succesful. Otherwise, reports an error and
2499 // returns false.
2500 void GenerateOopMap::expand_current_instr(int bci, int ilen, int newIlen, u_char inst_buffer[]) {
2501 Thread *THREAD = Thread::current(); // Could really have TRAPS argument.
2502 RelocCallback rcb(this);
2503 Relocator rc(_method, &rcb);
2504 methodHandle m= rc.insert_space_at(bci, newIlen, inst_buffer, THREAD);
2505 if (m.is_null() || HAS_PENDING_EXCEPTION) {
2506 report_error("could not rewrite method - exception occurred or bytecode buffer overflow");
2507 return;
2508 }
2509
2510 // Relocator returns a new method oop.
2511 _did_relocation = true;
2512 _method = m;
2513 }
2514
2515
2516 bool GenerateOopMap::is_astore(BytecodeStream *itr, int *index) {
2517 Bytecodes::Code bc = itr->code();
2518 switch(bc) {
2519 case Bytecodes::_astore_0:
2520 case Bytecodes::_astore_1:
2521 case Bytecodes::_astore_2:
2522 case Bytecodes::_astore_3:
2523 *index = bc - Bytecodes::_astore_0;
2524 return true;
2525 case Bytecodes::_astore:
2526 *index = itr->get_index();
2527 return true;
2528 default:
2529 return false;
2530 }
2531 }
2532
2533 bool GenerateOopMap::is_aload(BytecodeStream *itr, int *index) {
2534 Bytecodes::Code bc = itr->code();
2535 switch(bc) {
2536 case Bytecodes::_aload_0:
2537 case Bytecodes::_aload_1:
2538 case Bytecodes::_aload_2:
2539 case Bytecodes::_aload_3:
2540 *index = bc - Bytecodes::_aload_0;
2541 return true;
2542
2543 case Bytecodes::_aload:
2544 *index = itr->get_index();
2545 return true;
2546
2547 default:
2548 return false;
2549 }
2550 }
2551
2552
2553 // Return true iff the top of the operand stack holds a return address at
2554 // the current instruction
2555 bool GenerateOopMap::stack_top_holds_ret_addr(int bci) {
2556 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2557 if (_ret_adr_tos->at(i) == bci)
2558 return true;
2559 }
2560
2561 return false;
2562 }
2563
2564 void GenerateOopMap::compute_ret_adr_at_TOS() {
2565 assert(_ret_adr_tos != NULL, "must be initialized");
2566 _ret_adr_tos->clear();
2567
2568 for (int i = 0; i < bb_count(); i++) {
2569 BasicBlock* bb = &_basic_blocks[i];
2570
2571 // Make sure to only check basicblocks that are reachable
2572 if (bb->is_reachable()) {
2573
2574 // For each Basic block we check all instructions
2575 BytecodeStream bcs(_method);
2576 bcs.set_interval(bb->_bci, next_bb_start_pc(bb));
2577
2578 restore_state(bb);
2579
2580 while (bcs.next()>=0 && !_got_error) {
2581 // TDT: should this be is_good_address() ?
2582 if (_stack_top > 0 && stack()[_stack_top-1].is_address()) {
2583 _ret_adr_tos->append(bcs.bci());
2584 if (TraceNewOopMapGeneration) {
2585 tty->print_cr("Ret_adr TOS at bci: %d", bcs.bci());
2586 }
2587 }
2588 interp1(&bcs);
2589 }
2590 }
2591 }
2592 }
2593
2594 void GenerateOopMap::update_ret_adr_at_TOS(int bci, int delta) {
2595 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2596 int v = _ret_adr_tos->at(i);
2597 if (v > bci) _ret_adr_tos->at_put(i, v + delta);
2598 }
2599 }
2600
2601 // ===================================================================
2602
2603 #ifndef PRODUCT
2604 int ResolveOopMapConflicts::_nof_invocations = 0;
2605 int ResolveOopMapConflicts::_nof_rewrites = 0;
2606 int ResolveOopMapConflicts::_nof_relocations = 0;
2607 #endif
2608
2609 methodHandle ResolveOopMapConflicts::do_potential_rewrite(TRAPS) {
2610 compute_map(CHECK_(methodHandle()));
2611
2612 #ifndef PRODUCT
2613 // Tracking and statistics
2614 if (PrintRewrites) {
2615 _nof_invocations++;
2616 if (did_rewriting()) {
2617 _nof_rewrites++;
2618 if (did_relocation()) _nof_relocations++;
2619 tty->print("Method was rewritten %s: ", (did_relocation()) ? "and relocated" : "");
2620 method()->print_value(); tty->cr();
2621 tty->print_cr("Cand.: %d rewrts: %d (%d%%) reloc.: %d (%d%%)",
2622 _nof_invocations,
2623 _nof_rewrites, (_nof_rewrites * 100) / _nof_invocations,
2624 _nof_relocations, (_nof_relocations * 100) / _nof_invocations);
2625 }
2626 }
2627 #endif
2628 return methodHandle(THREAD, method());
2629 }