1 /*
2 * Copyright (c) 1997, 2011, 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 "oops/generateOopMap.hpp"
28 #include "oops/oop.inline.hpp"
29 #include "oops/symbol.hpp"
30 #include "runtime/handles.inline.hpp"
31 #include "runtime/java.hpp"
32 #include "runtime/relocator.hpp"
33 #include "utilities/bitMap.inline.hpp"
34
35 //
36 //
37 // Compute stack layouts for each instruction in method.
38 //
39 // Problems:
40 // - What to do about jsr with different types of local vars?
41 // Need maps that are conditional on jsr path?
42 // - Jsr and exceptions should be done more efficiently (the retAddr stuff)
43 //
44 // Alternative:
45 // - Could extend verifier to provide this information.
46 // For: one fewer abstract interpreter to maintain. Against: the verifier
47 // solves a bigger problem so slower (undesirable to force verification of
48 // everything?).
49 //
50 // Algorithm:
51 // Partition bytecodes into basic blocks
52 // For each basic block: store entry state (vars, stack). For instructions
53 // inside basic blocks we do not store any state (instead we recompute it
54 // from state produced by previous instruction).
55 //
56 // Perform abstract interpretation of bytecodes over this lattice:
57 //
58 // _--'#'--_
59 // / / \ \
60 // / / \ \
61 // / | | \
62 // 'r' 'v' 'p' ' '
63 // \ | | /
64 // \ \ / /
65 // \ \ / /
66 // -- '@' --
67 //
68 // '#' top, result of conflict merge
69 // 'r' reference type
70 // 'v' value type
71 // 'p' pc type for jsr/ret
72 // ' ' uninitialized; never occurs on operand stack in Java
73 // '@' bottom/unexecuted; initial state each bytecode.
74 //
75 // Basic block headers are the only merge points. We use this iteration to
76 // compute the information:
77 //
78 // find basic blocks;
79 // initialize them with uninitialized state;
80 // initialize first BB according to method signature;
81 // mark first BB changed
82 // while (some BB is changed) do {
83 // perform abstract interpration of all bytecodes in BB;
84 // merge exit state of BB into entry state of all successor BBs,
85 // noting if any of these change;
86 // }
87 //
88 // One additional complication is necessary. The jsr instruction pushes
89 // a return PC on the stack (a 'p' type in the abstract interpretation).
90 // To be able to process "ret" bytecodes, we keep track of these return
91 // PC's in a 'retAddrs' structure in abstract interpreter context (when
92 // processing a "ret" bytecodes, it is not sufficient to know that it gets
93 // an argument of the right type 'p'; we need to know which address it
94 // returns to).
95 //
96 // (Note this comment is borrowed form the original author of the algorithm)
97
98 // ComputeCallStack
99 //
100 // Specialization of SignatureIterator - compute the effects of a call
101 //
102 class ComputeCallStack : public SignatureIterator {
103 CellTypeState *_effect;
104 int _idx;
105
106 void setup();
107 void set(CellTypeState state) { _effect[_idx++] = state; }
108 int length() { return _idx; };
109
110 virtual void do_bool () { set(CellTypeState::value); };
111 virtual void do_char () { set(CellTypeState::value); };
112 virtual void do_float () { set(CellTypeState::value); };
113 virtual void do_byte () { set(CellTypeState::value); };
114 virtual void do_short () { set(CellTypeState::value); };
115 virtual void do_int () { set(CellTypeState::value); };
116 virtual void do_void () { set(CellTypeState::bottom);};
117 virtual void do_object(int begin, int end) { set(CellTypeState::ref); };
118 virtual void do_array (int begin, int end) { set(CellTypeState::ref); };
119
120 void do_double() { set(CellTypeState::value);
121 set(CellTypeState::value); }
122 void do_long () { set(CellTypeState::value);
123 set(CellTypeState::value); }
124
125 public:
126 ComputeCallStack(Symbol* signature) : SignatureIterator(signature) {};
127
128 // Compute methods
129 int compute_for_parameters(bool is_static, CellTypeState *effect) {
130 _idx = 0;
131 _effect = effect;
132
133 if (!is_static)
134 effect[_idx++] = CellTypeState::ref;
135
136 iterate_parameters();
137
138 return length();
139 };
140
141 int compute_for_returntype(CellTypeState *effect) {
142 _idx = 0;
143 _effect = effect;
144 iterate_returntype();
145 set(CellTypeState::bottom); // Always terminate with a bottom state, so ppush works
146
147 return length();
148 }
149 };
150
151 //=========================================================================================
152 // ComputeEntryStack
153 //
154 // Specialization of SignatureIterator - in order to set up first stack frame
155 //
156 class ComputeEntryStack : public SignatureIterator {
157 CellTypeState *_effect;
158 int _idx;
159
160 void setup();
161 void set(CellTypeState state) { _effect[_idx++] = state; }
162 int length() { return _idx; };
163
164 virtual void do_bool () { set(CellTypeState::value); };
165 virtual void do_char () { set(CellTypeState::value); };
166 virtual void do_float () { set(CellTypeState::value); };
167 virtual void do_byte () { set(CellTypeState::value); };
168 virtual void do_short () { set(CellTypeState::value); };
169 virtual void do_int () { set(CellTypeState::value); };
170 virtual void do_void () { set(CellTypeState::bottom);};
171 virtual void do_object(int begin, int end) { set(CellTypeState::make_slot_ref(_idx)); }
172 virtual void do_array (int begin, int end) { set(CellTypeState::make_slot_ref(_idx)); }
173
174 void do_double() { set(CellTypeState::value);
175 set(CellTypeState::value); }
176 void do_long () { set(CellTypeState::value);
177 set(CellTypeState::value); }
178
179 public:
180 ComputeEntryStack(Symbol* signature) : SignatureIterator(signature) {};
181
182 // Compute methods
183 int compute_for_parameters(bool is_static, CellTypeState *effect) {
184 _idx = 0;
185 _effect = effect;
186
187 if (!is_static)
188 effect[_idx++] = CellTypeState::make_slot_ref(0);
189
190 iterate_parameters();
191
192 return length();
193 };
194
195 int compute_for_returntype(CellTypeState *effect) {
196 _idx = 0;
197 _effect = effect;
198 iterate_returntype();
199 set(CellTypeState::bottom); // Always terminate with a bottom state, so ppush works
200
201 return length();
202 }
203 };
204
205 //=====================================================================================
206 //
207 // Implementation of RetTable/RetTableEntry
208 //
209 // Contains function to itereate through all bytecodes
210 // and find all return entry points
211 //
212 int RetTable::_init_nof_entries = 10;
213 int RetTableEntry::_init_nof_jsrs = 5;
214
215 void RetTableEntry::add_delta(int bci, int delta) {
216 if (_target_bci > bci) _target_bci += delta;
217
218 for (int k = 0; k < _jsrs->length(); k++) {
219 int jsr = _jsrs->at(k);
220 if (jsr > bci) _jsrs->at_put(k, jsr+delta);
221 }
222 }
223
224 void RetTable::compute_ret_table(methodHandle method) {
225 BytecodeStream i(method);
226 Bytecodes::Code bytecode;
227
228 while( (bytecode = i.next()) >= 0) {
229 switch (bytecode) {
230 case Bytecodes::_jsr:
231 add_jsr(i.next_bci(), i.dest());
232 break;
233 case Bytecodes::_jsr_w:
234 add_jsr(i.next_bci(), i.dest_w());
235 break;
236 }
237 }
238 }
239
240 void RetTable::add_jsr(int return_bci, int target_bci) {
241 RetTableEntry* entry = _first;
242
243 // Scan table for entry
244 for (;entry && entry->target_bci() != target_bci; entry = entry->next());
245
246 if (!entry) {
247 // Allocate new entry and put in list
248 entry = new RetTableEntry(target_bci, _first);
249 _first = entry;
250 }
251
252 // Now "entry" is set. Make sure that the entry is initialized
253 // and has room for the new jsr.
254 entry->add_jsr(return_bci);
255 }
256
257 RetTableEntry* RetTable::find_jsrs_for_target(int targBci) {
258 RetTableEntry *cur = _first;
259
260 while(cur) {
261 assert(cur->target_bci() != -1, "sanity check");
262 if (cur->target_bci() == targBci) return cur;
263 cur = cur->next();
264 }
265 ShouldNotReachHere();
266 return NULL;
267 }
268
269 // The instruction at bci is changing size by "delta". Update the return map.
270 void RetTable::update_ret_table(int bci, int delta) {
271 RetTableEntry *cur = _first;
272 while(cur) {
273 cur->add_delta(bci, delta);
274 cur = cur->next();
275 }
276 }
277
278 //
279 // Celltype state
280 //
281
282 CellTypeState CellTypeState::bottom = CellTypeState::make_bottom();
283 CellTypeState CellTypeState::uninit = CellTypeState::make_any(uninit_value);
284 CellTypeState CellTypeState::ref = CellTypeState::make_any(ref_conflict);
285 CellTypeState CellTypeState::value = CellTypeState::make_any(val_value);
286 CellTypeState CellTypeState::refUninit = CellTypeState::make_any(ref_conflict | uninit_value);
287 CellTypeState CellTypeState::top = CellTypeState::make_top();
288 CellTypeState CellTypeState::addr = CellTypeState::make_any(addr_conflict);
289
290 // Commonly used constants
291 static CellTypeState epsilonCTS[1] = { CellTypeState::bottom };
292 static CellTypeState refCTS = CellTypeState::ref;
293 static CellTypeState valCTS = CellTypeState::value;
294 static CellTypeState vCTS[2] = { CellTypeState::value, CellTypeState::bottom };
295 static CellTypeState rCTS[2] = { CellTypeState::ref, CellTypeState::bottom };
296 static CellTypeState rrCTS[3] = { CellTypeState::ref, CellTypeState::ref, CellTypeState::bottom };
297 static CellTypeState vrCTS[3] = { CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
298 static CellTypeState vvCTS[3] = { CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
299 static CellTypeState rvrCTS[4] = { CellTypeState::ref, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
300 static CellTypeState vvrCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
301 static CellTypeState vvvCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
302 static CellTypeState vvvrCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
303 static CellTypeState vvvvCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
304
305 char CellTypeState::to_char() const {
306 if (can_be_reference()) {
307 if (can_be_value() || can_be_address())
308 return '#'; // Conflict that needs to be rewritten
309 else
310 return 'r';
311 } else if (can_be_value())
312 return 'v';
313 else if (can_be_address())
314 return 'p';
315 else if (can_be_uninit())
316 return ' ';
317 else
318 return '@';
319 }
320
321
322 // Print a detailed CellTypeState. Indicate all bits that are set. If
323 // the CellTypeState represents an address or a reference, print the
324 // value of the additional information.
325 void CellTypeState::print(outputStream *os) {
326 if (can_be_address()) {
327 os->print("(p");
328 } else {
329 os->print("( ");
330 }
331 if (can_be_reference()) {
332 os->print("r");
333 } else {
334 os->print(" ");
335 }
336 if (can_be_value()) {
337 os->print("v");
338 } else {
339 os->print(" ");
340 }
341 if (can_be_uninit()) {
342 os->print("u|");
343 } else {
344 os->print(" |");
345 }
346 if (is_info_top()) {
347 os->print("Top)");
348 } else if (is_info_bottom()) {
349 os->print("Bot)");
350 } else {
351 if (is_reference()) {
352 int info = get_info();
353 int data = info & ~(ref_not_lock_bit | ref_slot_bit);
354 if (info & ref_not_lock_bit) {
355 // Not a monitor lock reference.
356 if (info & ref_slot_bit) {
357 // slot
358 os->print("slot%d)", data);
359 } else {
360 // line
361 os->print("line%d)", data);
362 }
363 } else {
364 // lock
365 os->print("lock%d)", data);
366 }
367 } else {
368 os->print("%d)", get_info());
369 }
370 }
371 }
372
373 //
374 // Basicblock handling methods
375 //
376
377 void GenerateOopMap ::initialize_bb() {
378 _gc_points = 0;
379 _bb_count = 0;
380 _bb_hdr_bits.clear();
381 _bb_hdr_bits.resize(method()->code_size());
382 }
383
384 void GenerateOopMap::bb_mark_fct(GenerateOopMap *c, int bci, int *data) {
385 assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
386 if (c->is_bb_header(bci))
387 return;
388
389 if (TraceNewOopMapGeneration) {
390 tty->print_cr("Basicblock#%d begins at: %d", c->_bb_count, bci);
391 }
392 c->set_bbmark_bit(bci);
393 c->_bb_count++;
394 }
395
396
397 void GenerateOopMap::mark_bbheaders_and_count_gc_points() {
398 initialize_bb();
399
400 bool fellThrough = false; // False to get first BB marked.
401
402 // First mark all exception handlers as start of a basic-block
403 typeArrayOop excps = method()->exception_table();
404 for(int i = 0; i < excps->length(); i += 4) {
405 int handler_pc_idx = i+2;
406 bb_mark_fct(this, excps->int_at(handler_pc_idx), NULL);
407 }
408
409 // Then iterate through the code
410 BytecodeStream bcs(_method);
411 Bytecodes::Code bytecode;
412
413 while( (bytecode = bcs.next()) >= 0) {
414 int bci = bcs.bci();
415
416 if (!fellThrough)
417 bb_mark_fct(this, bci, NULL);
418
419 fellThrough = jump_targets_do(&bcs, &GenerateOopMap::bb_mark_fct, NULL);
420
421 /* We will also mark successors of jsr's as basic block headers. */
422 switch (bytecode) {
423 case Bytecodes::_jsr:
424 assert(!fellThrough, "should not happen");
425 bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), NULL);
426 break;
427 case Bytecodes::_jsr_w:
428 assert(!fellThrough, "should not happen");
429 bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), NULL);
430 break;
431 }
432
433 if (possible_gc_point(&bcs))
434 _gc_points++;
435 }
436 }
437
438 void GenerateOopMap::reachable_basicblock(GenerateOopMap *c, int bci, int *data) {
439 assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
440 BasicBlock* bb = c->get_basic_block_at(bci);
441 if (bb->is_dead()) {
442 bb->mark_as_alive();
443 *data = 1; // Mark basicblock as changed
444 }
445 }
446
447
448 void GenerateOopMap::mark_reachable_code() {
449 int change = 1; // int to get function pointers to work
450
451 // Mark entry basic block as alive and all exception handlers
452 _basic_blocks[0].mark_as_alive();
453 typeArrayOop excps = method()->exception_table();
454 for(int i = 0; i < excps->length(); i += 4) {
455 int handler_pc_idx = i+2;
456 BasicBlock *bb = get_basic_block_at(excps->int_at(handler_pc_idx));
457 // If block is not already alive (due to multiple exception handlers to same bb), then
458 // make it alive
459 if (bb->is_dead()) bb->mark_as_alive();
460 }
461
462 BytecodeStream bcs(_method);
463
464 // Iterate through all basic blocks until we reach a fixpoint
465 while (change) {
466 change = 0;
467
468 for (int i = 0; i < _bb_count; i++) {
469 BasicBlock *bb = &_basic_blocks[i];
470 if (bb->is_alive()) {
471 // Position bytecodestream at last bytecode in basicblock
472 bcs.set_start(bb->_end_bci);
473 bcs.next();
474 Bytecodes::Code bytecode = bcs.code();
475 int bci = bcs.bci();
476 assert(bci == bb->_end_bci, "wrong bci");
477
478 bool fell_through = jump_targets_do(&bcs, &GenerateOopMap::reachable_basicblock, &change);
479
480 // We will also mark successors of jsr's as alive.
481 switch (bytecode) {
482 case Bytecodes::_jsr:
483 case Bytecodes::_jsr_w:
484 assert(!fell_through, "should not happen");
485 reachable_basicblock(this, bci + Bytecodes::length_for(bytecode), &change);
486 break;
487 }
488 if (fell_through) {
489 // Mark successor as alive
490 if (bb[1].is_dead()) {
491 bb[1].mark_as_alive();
492 change = 1;
493 }
494 }
495 }
496 }
497 }
498 }
499
500 /* If the current instruction in "c" has no effect on control flow,
501 returns "true". Otherwise, calls "jmpFct" one or more times, with
502 "c", an appropriate "pcDelta", and "data" as arguments, then
503 returns "false". There is one exception: if the current
504 instruction is a "ret", returns "false" without calling "jmpFct".
505 Arrangements for tracking the control flow of a "ret" must be made
506 externally. */
507 bool GenerateOopMap::jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int *data) {
508 int bci = bcs->bci();
509
510 switch (bcs->code()) {
511 case Bytecodes::_ifeq:
512 case Bytecodes::_ifne:
513 case Bytecodes::_iflt:
514 case Bytecodes::_ifge:
515 case Bytecodes::_ifgt:
516 case Bytecodes::_ifle:
517 case Bytecodes::_if_icmpeq:
518 case Bytecodes::_if_icmpne:
519 case Bytecodes::_if_icmplt:
520 case Bytecodes::_if_icmpge:
521 case Bytecodes::_if_icmpgt:
522 case Bytecodes::_if_icmple:
523 case Bytecodes::_if_acmpeq:
524 case Bytecodes::_if_acmpne:
525 case Bytecodes::_ifnull:
526 case Bytecodes::_ifnonnull:
527 (*jmpFct)(this, bcs->dest(), data);
528 (*jmpFct)(this, bci + 3, data);
529 break;
530
531 case Bytecodes::_goto:
532 (*jmpFct)(this, bcs->dest(), data);
533 break;
534 case Bytecodes::_goto_w:
535 (*jmpFct)(this, bcs->dest_w(), data);
536 break;
537 case Bytecodes::_tableswitch:
538 { Bytecode_tableswitch tableswitch(method(), bcs->bcp());
539 int len = tableswitch.length();
540
541 (*jmpFct)(this, bci + tableswitch.default_offset(), data); /* Default. jump address */
542 while (--len >= 0) {
543 (*jmpFct)(this, bci + tableswitch.dest_offset_at(len), data);
544 }
545 break;
546 }
547
548 case Bytecodes::_lookupswitch:
549 { Bytecode_lookupswitch lookupswitch(method(), bcs->bcp());
550 int npairs = lookupswitch.number_of_pairs();
551 (*jmpFct)(this, bci + lookupswitch.default_offset(), data); /* Default. */
552 while(--npairs >= 0) {
553 LookupswitchPair pair = lookupswitch.pair_at(npairs);
554 (*jmpFct)(this, bci + pair.offset(), data);
555 }
556 break;
557 }
558 case Bytecodes::_jsr:
559 assert(bcs->is_wide()==false, "sanity check");
560 (*jmpFct)(this, bcs->dest(), data);
561
562
563
564 break;
565 case Bytecodes::_jsr_w:
566 (*jmpFct)(this, bcs->dest_w(), data);
567 break;
568 case Bytecodes::_wide:
569 ShouldNotReachHere();
570 return true;
571 break;
572 case Bytecodes::_athrow:
573 case Bytecodes::_ireturn:
574 case Bytecodes::_lreturn:
575 case Bytecodes::_freturn:
576 case Bytecodes::_dreturn:
577 case Bytecodes::_areturn:
578 case Bytecodes::_return:
579 case Bytecodes::_ret:
580 break;
581 default:
582 return true;
583 }
584 return false;
585 }
586
587 /* Requires "pc" to be the head of a basic block; returns that basic
588 block. */
589 BasicBlock *GenerateOopMap::get_basic_block_at(int bci) const {
590 BasicBlock* bb = get_basic_block_containing(bci);
591 assert(bb->_bci == bci, "should have found BB");
592 return bb;
593 }
594
595 // Requires "pc" to be the start of an instruction; returns the basic
596 // block containing that instruction. */
597 BasicBlock *GenerateOopMap::get_basic_block_containing(int bci) const {
598 BasicBlock *bbs = _basic_blocks;
599 int lo = 0, hi = _bb_count - 1;
600
601 while (lo <= hi) {
602 int m = (lo + hi) / 2;
603 int mbci = bbs[m]._bci;
604 int nbci;
605
606 if ( m == _bb_count-1) {
607 assert( bci >= mbci && bci < method()->code_size(), "sanity check failed");
608 return bbs+m;
609 } else {
610 nbci = bbs[m+1]._bci;
611 }
612
613 if ( mbci <= bci && bci < nbci) {
614 return bbs+m;
615 } else if (mbci < bci) {
616 lo = m + 1;
617 } else {
618 assert(mbci > bci, "sanity check");
619 hi = m - 1;
620 }
621 }
622
623 fatal("should have found BB");
624 return NULL;
625 }
626
627 void GenerateOopMap::restore_state(BasicBlock *bb)
628 {
629 memcpy(_state, bb->_state, _state_len*sizeof(CellTypeState));
630 _stack_top = bb->_stack_top;
631 _monitor_top = bb->_monitor_top;
632 }
633
634 int GenerateOopMap::next_bb_start_pc(BasicBlock *bb) {
635 int bbNum = bb - _basic_blocks + 1;
636 if (bbNum == _bb_count)
637 return method()->code_size();
638
639 return _basic_blocks[bbNum]._bci;
640 }
641
642 //
643 // CellType handling methods
644 //
645
646 void GenerateOopMap::init_state() {
647 _state_len = _max_locals + _max_stack + _max_monitors;
648 _state = NEW_RESOURCE_ARRAY(CellTypeState, _state_len);
649 memset(_state, 0, _state_len * sizeof(CellTypeState));
650 _state_vec_buf = NEW_RESOURCE_ARRAY(char, MAX3(_max_locals, _max_stack, _max_monitors) + 1/*for null terminator char */);
651 }
652
653 void GenerateOopMap::make_context_uninitialized() {
654 CellTypeState* vs = vars();
655
656 for (int i = 0; i < _max_locals; i++)
657 vs[i] = CellTypeState::uninit;
658
659 _stack_top = 0;
660 _monitor_top = 0;
661 }
662
663 int GenerateOopMap::methodsig_to_effect(Symbol* signature, bool is_static, CellTypeState* effect) {
664 ComputeEntryStack ces(signature);
665 return ces.compute_for_parameters(is_static, effect);
666 }
667
668 // Return result of merging cts1 and cts2.
669 CellTypeState CellTypeState::merge(CellTypeState cts, int slot) const {
670 CellTypeState result;
671
672 assert(!is_bottom() && !cts.is_bottom(),
673 "merge of bottom values is handled elsewhere");
674
675 result._state = _state | cts._state;
676
677 // If the top bit is set, we don't need to do any more work.
678 if (!result.is_info_top()) {
679 assert((result.can_be_address() || result.can_be_reference()),
680 "only addresses and references have non-top info");
681
682 if (!equal(cts)) {
683 // The two values being merged are different. Raise to top.
684 if (result.is_reference()) {
685 result = CellTypeState::make_slot_ref(slot);
686 } else {
687 result._state |= info_conflict;
688 }
689 }
690 }
691 assert(result.is_valid_state(), "checking that CTS merge maintains legal state");
692
693 return result;
694 }
695
696 // Merge the variable state for locals and stack from cts into bbts.
697 bool GenerateOopMap::merge_local_state_vectors(CellTypeState* cts,
698 CellTypeState* bbts) {
699 int i;
700 int len = _max_locals + _stack_top;
701 bool change = false;
702
703 for (i = len - 1; i >= 0; i--) {
704 CellTypeState v = cts[i].merge(bbts[i], i);
705 change = change || !v.equal(bbts[i]);
706 bbts[i] = v;
707 }
708
709 return change;
710 }
711
712 // Merge the monitor stack state from cts into bbts.
713 bool GenerateOopMap::merge_monitor_state_vectors(CellTypeState* cts,
714 CellTypeState* bbts) {
715 bool change = false;
716 if (_max_monitors > 0 && _monitor_top != bad_monitors) {
717 // If there are no monitors in the program, or there has been
718 // a monitor matching error before this point in the program,
719 // then we do not merge in the monitor state.
720
721 int base = _max_locals + _max_stack;
722 int len = base + _monitor_top;
723 for (int i = len - 1; i >= base; i--) {
724 CellTypeState v = cts[i].merge(bbts[i], i);
725
726 // Can we prove that, when there has been a change, it will already
727 // have been detected at this point? That would make this equal
728 // check here unnecessary.
729 change = change || !v.equal(bbts[i]);
730 bbts[i] = v;
731 }
732 }
733
734 return change;
735 }
736
737 void GenerateOopMap::copy_state(CellTypeState *dst, CellTypeState *src) {
738 int len = _max_locals + _stack_top;
739 for (int i = 0; i < len; i++) {
740 if (src[i].is_nonlock_reference()) {
741 dst[i] = CellTypeState::make_slot_ref(i);
742 } else {
743 dst[i] = src[i];
744 }
745 }
746 if (_max_monitors > 0 && _monitor_top != bad_monitors) {
747 int base = _max_locals + _max_stack;
748 len = base + _monitor_top;
749 for (int i = base; i < len; i++) {
750 dst[i] = src[i];
751 }
752 }
753 }
754
755
756 // Merge the states for the current block and the next. As long as a
757 // block is reachable the locals and stack must be merged. If the
758 // stack heights don't match then this is a verification error and
759 // it's impossible to interpret the code. Simultaneously monitor
760 // states are being check to see if they nest statically. If monitor
761 // depths match up then their states are merged. Otherwise the
762 // mismatch is simply recorded and interpretation continues since
763 // monitor matching is purely informational and doesn't say anything
764 // about the correctness of the code.
765 void GenerateOopMap::merge_state_into_bb(BasicBlock *bb) {
766 assert(bb->is_alive(), "merging state into a dead basicblock");
767
768 if (_stack_top == bb->_stack_top) {
769 // always merge local state even if monitors don't match.
770 if (merge_local_state_vectors(_state, bb->_state)) {
771 bb->set_changed(true);
772 }
773 if (_monitor_top == bb->_monitor_top) {
774 // monitors still match so continue merging monitor states.
775 if (merge_monitor_state_vectors(_state, bb->_state)) {
776 bb->set_changed(true);
777 }
778 } else {
779 if (TraceMonitorMismatch) {
780 report_monitor_mismatch("monitor stack height merge conflict");
781 }
782 // When the monitor stacks are not matched, we set _monitor_top to
783 // bad_monitors. This signals that, from here on, the monitor stack cannot
784 // be trusted. In particular, monitorexit bytecodes may throw
785 // exceptions. We mark this block as changed so that the change
786 // propagates properly.
787 bb->_monitor_top = bad_monitors;
788 bb->set_changed(true);
789 _monitor_safe = false;
790 }
791 } else if (!bb->is_reachable()) {
792 // First time we look at this BB
793 copy_state(bb->_state, _state);
794 bb->_stack_top = _stack_top;
795 bb->_monitor_top = _monitor_top;
796 bb->set_changed(true);
797 } else {
798 verify_error("stack height conflict: %d vs. %d", _stack_top, bb->_stack_top);
799 }
800 }
801
802 void GenerateOopMap::merge_state(GenerateOopMap *gom, int bci, int* data) {
803 gom->merge_state_into_bb(gom->get_basic_block_at(bci));
804 }
805
806 void GenerateOopMap::set_var(int localNo, CellTypeState cts) {
807 assert(cts.is_reference() || cts.is_value() || cts.is_address(),
808 "wrong celltypestate");
809 if (localNo < 0 || localNo > _max_locals) {
810 verify_error("variable write error: r%d", localNo);
811 return;
812 }
813 vars()[localNo] = cts;
814 }
815
816 CellTypeState GenerateOopMap::get_var(int localNo) {
817 assert(localNo < _max_locals + _nof_refval_conflicts, "variable read error");
818 if (localNo < 0 || localNo > _max_locals) {
819 verify_error("variable read error: r%d", localNo);
820 return valCTS; // just to pick something;
821 }
822 return vars()[localNo];
823 }
824
825 CellTypeState GenerateOopMap::pop() {
826 if ( _stack_top <= 0) {
827 verify_error("stack underflow");
828 return valCTS; // just to pick something
829 }
830 return stack()[--_stack_top];
831 }
832
833 void GenerateOopMap::push(CellTypeState cts) {
834 if ( _stack_top >= _max_stack) {
835 verify_error("stack overflow");
836 return;
837 }
838 stack()[_stack_top++] = cts;
839 }
840
841 CellTypeState GenerateOopMap::monitor_pop() {
842 assert(_monitor_top != bad_monitors, "monitor_pop called on error monitor stack");
843 if (_monitor_top == 0) {
844 // We have detected a pop of an empty monitor stack.
845 _monitor_safe = false;
846 _monitor_top = bad_monitors;
847
848 if (TraceMonitorMismatch) {
849 report_monitor_mismatch("monitor stack underflow");
850 }
851 return CellTypeState::ref; // just to keep the analysis going.
852 }
853 return monitors()[--_monitor_top];
854 }
855
856 void GenerateOopMap::monitor_push(CellTypeState cts) {
857 assert(_monitor_top != bad_monitors, "monitor_push called on error monitor stack");
858 if (_monitor_top >= _max_monitors) {
859 // Some monitorenter is being executed more than once.
860 // This means that the monitor stack cannot be simulated.
861 _monitor_safe = false;
862 _monitor_top = bad_monitors;
863
864 if (TraceMonitorMismatch) {
865 report_monitor_mismatch("monitor stack overflow");
866 }
867 return;
868 }
869 monitors()[_monitor_top++] = cts;
870 }
871
872 //
873 // Interpretation handling methods
874 //
875
876 void GenerateOopMap::do_interpretation()
877 {
878 // "i" is just for debugging, so we can detect cases where this loop is
879 // iterated more than once.
880 int i = 0;
881 do {
882 #ifndef PRODUCT
883 if (TraceNewOopMapGeneration) {
884 tty->print("\n\nIteration #%d of do_interpretation loop, method:\n", i);
885 method()->print_name(tty);
886 tty->print("\n\n");
887 }
888 #endif
889 _conflict = false;
890 _monitor_safe = true;
891 // init_state is now called from init_basic_blocks. The length of a
892 // state vector cannot be determined until we have made a pass through
893 // the bytecodes counting the possible monitor entries.
894 if (!_got_error) init_basic_blocks();
895 if (!_got_error) setup_method_entry_state();
896 if (!_got_error) interp_all();
897 if (!_got_error) rewrite_refval_conflicts();
898 i++;
899 } while (_conflict && !_got_error);
900 }
901
902 void GenerateOopMap::init_basic_blocks() {
903 // Note: Could consider reserving only the needed space for each BB's state
904 // (entry stack may not be of maximal height for every basic block).
905 // But cumbersome since we don't know the stack heights yet. (Nor the
906 // monitor stack heights...)
907
908 _basic_blocks = NEW_RESOURCE_ARRAY(BasicBlock, _bb_count);
909
910 // Make a pass through the bytecodes. Count the number of monitorenters.
911 // This can be used an upper bound on the monitor stack depth in programs
912 // which obey stack discipline with their monitor usage. Initialize the
913 // known information about basic blocks.
914 BytecodeStream j(_method);
915 Bytecodes::Code bytecode;
916
917 int bbNo = 0;
918 int monitor_count = 0;
919 int prev_bci = -1;
920 while( (bytecode = j.next()) >= 0) {
921 if (j.code() == Bytecodes::_monitorenter) {
922 monitor_count++;
923 }
924
925 int bci = j.bci();
926 if (is_bb_header(bci)) {
927 // Initialize the basicblock structure
928 BasicBlock *bb = _basic_blocks + bbNo;
929 bb->_bci = bci;
930 bb->_max_locals = _max_locals;
931 bb->_max_stack = _max_stack;
932 bb->set_changed(false);
933 bb->_stack_top = BasicBlock::_dead_basic_block; // Initialize all basicblocks are dead.
934 bb->_monitor_top = bad_monitors;
935
936 if (bbNo > 0) {
937 _basic_blocks[bbNo - 1]._end_bci = prev_bci;
938 }
939
940 bbNo++;
941 }
942 // Remember prevous bci.
943 prev_bci = bci;
944 }
945 // Set
946 _basic_blocks[bbNo-1]._end_bci = prev_bci;
947
948
949 // Check that the correct number of basicblocks was found
950 if (bbNo !=_bb_count) {
951 if (bbNo < _bb_count) {
952 verify_error("jump into the middle of instruction?");
953 return;
954 } else {
955 verify_error("extra basic blocks - should not happen?");
956 return;
957 }
958 }
959
960 _max_monitors = monitor_count;
961
962 // Now that we have a bound on the depth of the monitor stack, we can
963 // initialize the CellTypeState-related information.
964 init_state();
965
966 // We allocate space for all state-vectors for all basicblocks in one huge chuck.
967 // Then in the next part of the code, we set a pointer in each _basic_block that
968 // points to each piece.
969 CellTypeState *basicBlockState = NEW_RESOURCE_ARRAY(CellTypeState, bbNo * _state_len);
970 memset(basicBlockState, 0, bbNo * _state_len * sizeof(CellTypeState));
971
972 // Make a pass over the basicblocks and assign their state vectors.
973 for (int blockNum=0; blockNum < bbNo; blockNum++) {
974 BasicBlock *bb = _basic_blocks + blockNum;
975 bb->_state = basicBlockState + blockNum * _state_len;
976
977 #ifdef ASSERT
978 if (blockNum + 1 < bbNo) {
979 address bcp = _method->bcp_from(bb->_end_bci);
980 int bc_len = Bytecodes::java_length_at(_method(), bcp);
981 assert(bb->_end_bci + bc_len == bb[1]._bci, "unmatched bci info in basicblock");
982 }
983 #endif
984 }
985 #ifdef ASSERT
986 { BasicBlock *bb = &_basic_blocks[bbNo-1];
987 address bcp = _method->bcp_from(bb->_end_bci);
988 int bc_len = Bytecodes::java_length_at(_method(), bcp);
989 assert(bb->_end_bci + bc_len == _method->code_size(), "wrong end bci");
990 }
991 #endif
992
993 // Mark all alive blocks
994 mark_reachable_code();
995 }
996
997 void GenerateOopMap::setup_method_entry_state() {
998
999 // Initialize all locals to 'uninit' and set stack-height to 0
1000 make_context_uninitialized();
1001
1002 // Initialize CellState type of arguments
1003 methodsig_to_effect(method()->signature(), method()->is_static(), vars());
1004
1005 // If some references must be pre-assigned to null, then set that up
1006 initialize_vars();
1007
1008 // This is the start state
1009 merge_state_into_bb(&_basic_blocks[0]);
1010
1011 assert(_basic_blocks[0].changed(), "we are not getting off the ground");
1012 }
1013
1014 // The instruction at bci is changing size by "delta". Update the basic blocks.
1015 void GenerateOopMap::update_basic_blocks(int bci, int delta,
1016 int new_method_size) {
1017 assert(new_method_size >= method()->code_size() + delta,
1018 "new method size is too small");
1019
1020 BitMap::bm_word_t* new_bb_hdr_bits =
1021 NEW_RESOURCE_ARRAY(BitMap::bm_word_t,
1022 BitMap::word_align_up(new_method_size));
1023 _bb_hdr_bits.set_map(new_bb_hdr_bits);
1024 _bb_hdr_bits.set_size(new_method_size);
1025 _bb_hdr_bits.clear();
1026
1027
1028 for(int k = 0; k < _bb_count; k++) {
1029 if (_basic_blocks[k]._bci > bci) {
1030 _basic_blocks[k]._bci += delta;
1031 _basic_blocks[k]._end_bci += delta;
1032 }
1033 _bb_hdr_bits.at_put(_basic_blocks[k]._bci, true);
1034 }
1035 }
1036
1037 //
1038 // Initvars handling
1039 //
1040
1041 void GenerateOopMap::initialize_vars() {
1042 for (int k = 0; k < _init_vars->length(); k++)
1043 _state[_init_vars->at(k)] = CellTypeState::make_slot_ref(k);
1044 }
1045
1046 void GenerateOopMap::add_to_ref_init_set(int localNo) {
1047
1048 if (TraceNewOopMapGeneration)
1049 tty->print_cr("Added init vars: %d", localNo);
1050
1051 // Is it already in the set?
1052 if (_init_vars->contains(localNo) )
1053 return;
1054
1055 _init_vars->append(localNo);
1056 }
1057
1058 //
1059 // Interpreration code
1060 //
1061
1062 void GenerateOopMap::interp_all() {
1063 bool change = true;
1064
1065 while (change && !_got_error) {
1066 change = false;
1067 for (int i = 0; i < _bb_count && !_got_error; i++) {
1068 BasicBlock *bb = &_basic_blocks[i];
1069 if (bb->changed()) {
1070 if (_got_error) return;
1071 change = true;
1072 bb->set_changed(false);
1073 interp_bb(bb);
1074 }
1075 }
1076 }
1077 }
1078
1079 void GenerateOopMap::interp_bb(BasicBlock *bb) {
1080
1081 // We do not want to do anything in case the basic-block has not been initialized. This
1082 // will happen in the case where there is dead-code hang around in a method.
1083 assert(bb->is_reachable(), "should be reachable or deadcode exist");
1084 restore_state(bb);
1085
1086 BytecodeStream itr(_method);
1087
1088 // Set iterator interval to be the current basicblock
1089 int lim_bci = next_bb_start_pc(bb);
1090 itr.set_interval(bb->_bci, lim_bci);
1091 assert(lim_bci != bb->_bci, "must be at least one instruction in a basicblock");
1092 itr.next(); // read first instruction
1093
1094 // Iterates through all bytecodes except the last in a basic block.
1095 // We handle the last one special, since there is controlflow change.
1096 while(itr.next_bci() < lim_bci && !_got_error) {
1097 if (_has_exceptions || _monitor_top != 0) {
1098 // We do not need to interpret the results of exceptional
1099 // continuation from this instruction when the method has no
1100 // exception handlers and the monitor stack is currently
1101 // empty.
1102 do_exception_edge(&itr);
1103 }
1104 interp1(&itr);
1105 itr.next();
1106 }
1107
1108 // Handle last instruction.
1109 if (!_got_error) {
1110 assert(itr.next_bci() == lim_bci, "must point to end");
1111 if (_has_exceptions || _monitor_top != 0) {
1112 do_exception_edge(&itr);
1113 }
1114 interp1(&itr);
1115
1116 bool fall_through = jump_targets_do(&itr, GenerateOopMap::merge_state, NULL);
1117 if (_got_error) return;
1118
1119 if (itr.code() == Bytecodes::_ret) {
1120 assert(!fall_through, "cannot be set if ret instruction");
1121 // Automatically handles 'wide' ret indicies
1122 ret_jump_targets_do(&itr, GenerateOopMap::merge_state, itr.get_index(), NULL);
1123 } else if (fall_through) {
1124 // Hit end of BB, but the instr. was a fall-through instruction,
1125 // so perform transition as if the BB ended in a "jump".
1126 if (lim_bci != bb[1]._bci) {
1127 verify_error("bytecodes fell through last instruction");
1128 return;
1129 }
1130 merge_state_into_bb(bb + 1);
1131 }
1132 }
1133 }
1134
1135 void GenerateOopMap::do_exception_edge(BytecodeStream* itr) {
1136 // Only check exception edge, if bytecode can trap
1137 if (!Bytecodes::can_trap(itr->code())) return;
1138 switch (itr->code()) {
1139 case Bytecodes::_aload_0:
1140 // These bytecodes can trap for rewriting. We need to assume that
1141 // they do not throw exceptions to make the monitor analysis work.
1142 return;
1143
1144 case Bytecodes::_ireturn:
1145 case Bytecodes::_lreturn:
1146 case Bytecodes::_freturn:
1147 case Bytecodes::_dreturn:
1148 case Bytecodes::_areturn:
1149 case Bytecodes::_return:
1150 // If the monitor stack height is not zero when we leave the method,
1151 // then we are either exiting with a non-empty stack or we have
1152 // found monitor trouble earlier in our analysis. In either case,
1153 // assume an exception could be taken here.
1154 if (_monitor_top == 0) {
1155 return;
1156 }
1157 break;
1158
1159 case Bytecodes::_monitorexit:
1160 // If the monitor stack height is bad_monitors, then we have detected a
1161 // monitor matching problem earlier in the analysis. If the
1162 // monitor stack height is 0, we are about to pop a monitor
1163 // off of an empty stack. In either case, the bytecode
1164 // could throw an exception.
1165 if (_monitor_top != bad_monitors && _monitor_top != 0) {
1166 return;
1167 }
1168 break;
1169 }
1170
1171 if (_has_exceptions) {
1172 int bci = itr->bci();
1173 typeArrayOop exct = method()->exception_table();
1174 for(int i = 0; i< exct->length(); i+=4) {
1175 int start_pc = exct->int_at(i);
1176 int end_pc = exct->int_at(i+1);
1177 int handler_pc = exct->int_at(i+2);
1178 int catch_type = exct->int_at(i+3);
1179
1180 if (start_pc <= bci && bci < end_pc) {
1181 BasicBlock *excBB = get_basic_block_at(handler_pc);
1182 CellTypeState *excStk = excBB->stack();
1183 CellTypeState *cOpStck = stack();
1184 CellTypeState cOpStck_0 = cOpStck[0];
1185 int cOpStackTop = _stack_top;
1186
1187 // Exception stacks are always the same.
1188 assert(method()->max_stack() > 0, "sanity check");
1189
1190 // We remembered the size and first element of "cOpStck"
1191 // above; now we temporarily set them to the appropriate
1192 // values for an exception handler. */
1193 cOpStck[0] = CellTypeState::make_slot_ref(_max_locals);
1194 _stack_top = 1;
1195
1196 merge_state_into_bb(excBB);
1197
1198 // Now undo the temporary change.
1199 cOpStck[0] = cOpStck_0;
1200 _stack_top = cOpStackTop;
1201
1202 // If this is a "catch all" handler, then we do not need to
1203 // consider any additional handlers.
1204 if (catch_type == 0) {
1205 return;
1206 }
1207 }
1208 }
1209 }
1210
1211 // It is possible that none of the exception handlers would have caught
1212 // the exception. In this case, we will exit the method. We must
1213 // ensure that the monitor stack is empty in this case.
1214 if (_monitor_top == 0) {
1215 return;
1216 }
1217
1218 // We pessimistically assume that this exception can escape the
1219 // method. (It is possible that it will always be caught, but
1220 // we don't care to analyse the types of the catch clauses.)
1221
1222 // We don't set _monitor_top to bad_monitors because there are no successors
1223 // to this exceptional exit.
1224
1225 if (TraceMonitorMismatch && _monitor_safe) {
1226 // We check _monitor_safe so that we only report the first mismatched
1227 // exceptional exit.
1228 report_monitor_mismatch("non-empty monitor stack at exceptional exit");
1229 }
1230 _monitor_safe = false;
1231
1232 }
1233
1234 void GenerateOopMap::report_monitor_mismatch(const char *msg) {
1235 #ifndef PRODUCT
1236 tty->print(" Monitor mismatch in method ");
1237 method()->print_short_name(tty);
1238 tty->print_cr(": %s", msg);
1239 #endif
1240 }
1241
1242 void GenerateOopMap::print_states(outputStream *os,
1243 CellTypeState* vec, int num) {
1244 for (int i = 0; i < num; i++) {
1245 vec[i].print(tty);
1246 }
1247 }
1248
1249 // Print the state values at the current bytecode.
1250 void GenerateOopMap::print_current_state(outputStream *os,
1251 BytecodeStream *currentBC,
1252 bool detailed) {
1253
1254 if (detailed) {
1255 os->print(" %4d vars = ", currentBC->bci());
1256 print_states(os, vars(), _max_locals);
1257 os->print(" %s", Bytecodes::name(currentBC->code()));
1258 switch(currentBC->code()) {
1259 case Bytecodes::_invokevirtual:
1260 case Bytecodes::_invokespecial:
1261 case Bytecodes::_invokestatic:
1262 case Bytecodes::_invokedynamic:
1263 case Bytecodes::_invokeinterface:
1264 int idx = currentBC->has_index_u4() ? currentBC->get_index_u4() : currentBC->get_index_u2_cpcache();
1265 constantPoolOop cp = method()->constants();
1266 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
1267 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1268 Symbol* signature = cp->symbol_at(signatureIdx);
1269 os->print("%s", signature->as_C_string());
1270 }
1271 os->cr();
1272 os->print(" stack = ");
1273 print_states(os, stack(), _stack_top);
1274 os->cr();
1275 if (_monitor_top != bad_monitors) {
1276 os->print(" monitors = ");
1277 print_states(os, monitors(), _monitor_top);
1278 } else {
1279 os->print(" [bad monitor stack]");
1280 }
1281 os->cr();
1282 } else {
1283 os->print(" %4d vars = '%s' ", currentBC->bci(), state_vec_to_string(vars(), _max_locals));
1284 os->print(" stack = '%s' ", state_vec_to_string(stack(), _stack_top));
1285 if (_monitor_top != bad_monitors) {
1286 os->print(" monitors = '%s' \t%s", state_vec_to_string(monitors(), _monitor_top), Bytecodes::name(currentBC->code()));
1287 } else {
1288 os->print(" [bad monitor stack]");
1289 }
1290 switch(currentBC->code()) {
1291 case Bytecodes::_invokevirtual:
1292 case Bytecodes::_invokespecial:
1293 case Bytecodes::_invokestatic:
1294 case Bytecodes::_invokedynamic:
1295 case Bytecodes::_invokeinterface:
1296 int idx = currentBC->has_index_u4() ? currentBC->get_index_u4() : currentBC->get_index_u2_cpcache();
1297 constantPoolOop cp = method()->constants();
1298 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
1299 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1300 Symbol* signature = cp->symbol_at(signatureIdx);
1301 os->print("%s", signature->as_C_string());
1302 }
1303 os->cr();
1304 }
1305 }
1306
1307 // Sets the current state to be the state after executing the
1308 // current instruction, starting in the current state.
1309 void GenerateOopMap::interp1(BytecodeStream *itr) {
1310 if (TraceNewOopMapGeneration) {
1311 print_current_state(tty, itr, TraceNewOopMapGenerationDetailed);
1312 }
1313
1314 // Should we report the results? Result is reported *before* the instruction at the current bci is executed.
1315 // However, not for calls. For calls we do not want to include the arguments, so we postpone the reporting until
1316 // they have been popped (in method ppl).
1317 if (_report_result == true) {
1318 switch(itr->code()) {
1319 case Bytecodes::_invokevirtual:
1320 case Bytecodes::_invokespecial:
1321 case Bytecodes::_invokestatic:
1322 case Bytecodes::_invokedynamic:
1323 case Bytecodes::_invokeinterface:
1324 _itr_send = itr;
1325 _report_result_for_send = true;
1326 break;
1327 default:
1328 fill_stackmap_for_opcodes(itr, vars(), stack(), _stack_top);
1329 break;
1330 }
1331 }
1332
1333 // abstract interpretation of current opcode
1334 switch(itr->code()) {
1335 case Bytecodes::_nop: break;
1336 case Bytecodes::_goto: break;
1337 case Bytecodes::_goto_w: break;
1338 case Bytecodes::_iinc: break;
1339 case Bytecodes::_return: do_return_monitor_check();
1340 break;
1341
1342 case Bytecodes::_aconst_null:
1343 case Bytecodes::_new: ppush1(CellTypeState::make_line_ref(itr->bci()));
1344 break;
1345
1346 case Bytecodes::_iconst_m1:
1347 case Bytecodes::_iconst_0:
1348 case Bytecodes::_iconst_1:
1349 case Bytecodes::_iconst_2:
1350 case Bytecodes::_iconst_3:
1351 case Bytecodes::_iconst_4:
1352 case Bytecodes::_iconst_5:
1353 case Bytecodes::_fconst_0:
1354 case Bytecodes::_fconst_1:
1355 case Bytecodes::_fconst_2:
1356 case Bytecodes::_bipush:
1357 case Bytecodes::_sipush: ppush1(valCTS); break;
1358
1359 case Bytecodes::_lconst_0:
1360 case Bytecodes::_lconst_1:
1361 case Bytecodes::_dconst_0:
1362 case Bytecodes::_dconst_1: ppush(vvCTS); break;
1363
1364 case Bytecodes::_ldc2_w: ppush(vvCTS); break;
1365
1366 case Bytecodes::_ldc: // fall through:
1367 case Bytecodes::_ldc_w: do_ldc(itr->bci()); break;
1368
1369 case Bytecodes::_iload:
1370 case Bytecodes::_fload: ppload(vCTS, itr->get_index()); break;
1371
1372 case Bytecodes::_lload:
1373 case Bytecodes::_dload: ppload(vvCTS,itr->get_index()); break;
1374
1375 case Bytecodes::_aload: ppload(rCTS, itr->get_index()); break;
1376
1377 case Bytecodes::_iload_0:
1378 case Bytecodes::_fload_0: ppload(vCTS, 0); break;
1379 case Bytecodes::_iload_1:
1380 case Bytecodes::_fload_1: ppload(vCTS, 1); break;
1381 case Bytecodes::_iload_2:
1382 case Bytecodes::_fload_2: ppload(vCTS, 2); break;
1383 case Bytecodes::_iload_3:
1384 case Bytecodes::_fload_3: ppload(vCTS, 3); break;
1385
1386 case Bytecodes::_lload_0:
1387 case Bytecodes::_dload_0: ppload(vvCTS, 0); break;
1388 case Bytecodes::_lload_1:
1389 case Bytecodes::_dload_1: ppload(vvCTS, 1); break;
1390 case Bytecodes::_lload_2:
1391 case Bytecodes::_dload_2: ppload(vvCTS, 2); break;
1392 case Bytecodes::_lload_3:
1393 case Bytecodes::_dload_3: ppload(vvCTS, 3); break;
1394
1395 case Bytecodes::_aload_0: ppload(rCTS, 0); break;
1396 case Bytecodes::_aload_1: ppload(rCTS, 1); break;
1397 case Bytecodes::_aload_2: ppload(rCTS, 2); break;
1398 case Bytecodes::_aload_3: ppload(rCTS, 3); break;
1399
1400 case Bytecodes::_iaload:
1401 case Bytecodes::_faload:
1402 case Bytecodes::_baload:
1403 case Bytecodes::_caload:
1404 case Bytecodes::_saload: pp(vrCTS, vCTS); break;
1405
1406 case Bytecodes::_laload: pp(vrCTS, vvCTS); break;
1407 case Bytecodes::_daload: pp(vrCTS, vvCTS); break;
1408
1409 case Bytecodes::_aaload: pp_new_ref(vrCTS, itr->bci()); break;
1410
1411 case Bytecodes::_istore:
1412 case Bytecodes::_fstore: ppstore(vCTS, itr->get_index()); break;
1413
1414 case Bytecodes::_lstore:
1415 case Bytecodes::_dstore: ppstore(vvCTS, itr->get_index()); break;
1416
1417 case Bytecodes::_astore: do_astore(itr->get_index()); break;
1418
1419 case Bytecodes::_istore_0:
1420 case Bytecodes::_fstore_0: ppstore(vCTS, 0); break;
1421 case Bytecodes::_istore_1:
1422 case Bytecodes::_fstore_1: ppstore(vCTS, 1); break;
1423 case Bytecodes::_istore_2:
1424 case Bytecodes::_fstore_2: ppstore(vCTS, 2); break;
1425 case Bytecodes::_istore_3:
1426 case Bytecodes::_fstore_3: ppstore(vCTS, 3); break;
1427
1428 case Bytecodes::_lstore_0:
1429 case Bytecodes::_dstore_0: ppstore(vvCTS, 0); break;
1430 case Bytecodes::_lstore_1:
1431 case Bytecodes::_dstore_1: ppstore(vvCTS, 1); break;
1432 case Bytecodes::_lstore_2:
1433 case Bytecodes::_dstore_2: ppstore(vvCTS, 2); break;
1434 case Bytecodes::_lstore_3:
1435 case Bytecodes::_dstore_3: ppstore(vvCTS, 3); break;
1436
1437 case Bytecodes::_astore_0: do_astore(0); break;
1438 case Bytecodes::_astore_1: do_astore(1); break;
1439 case Bytecodes::_astore_2: do_astore(2); break;
1440 case Bytecodes::_astore_3: do_astore(3); break;
1441
1442 case Bytecodes::_iastore:
1443 case Bytecodes::_fastore:
1444 case Bytecodes::_bastore:
1445 case Bytecodes::_castore:
1446 case Bytecodes::_sastore: ppop(vvrCTS); break;
1447 case Bytecodes::_lastore:
1448 case Bytecodes::_dastore: ppop(vvvrCTS); break;
1449 case Bytecodes::_aastore: ppop(rvrCTS); break;
1450
1451 case Bytecodes::_pop: ppop_any(1); break;
1452 case Bytecodes::_pop2: ppop_any(2); break;
1453
1454 case Bytecodes::_dup: ppdupswap(1, "11"); break;
1455 case Bytecodes::_dup_x1: ppdupswap(2, "121"); break;
1456 case Bytecodes::_dup_x2: ppdupswap(3, "1321"); break;
1457 case Bytecodes::_dup2: ppdupswap(2, "2121"); break;
1458 case Bytecodes::_dup2_x1: ppdupswap(3, "21321"); break;
1459 case Bytecodes::_dup2_x2: ppdupswap(4, "214321"); break;
1460 case Bytecodes::_swap: ppdupswap(2, "12"); break;
1461
1462 case Bytecodes::_iadd:
1463 case Bytecodes::_fadd:
1464 case Bytecodes::_isub:
1465 case Bytecodes::_fsub:
1466 case Bytecodes::_imul:
1467 case Bytecodes::_fmul:
1468 case Bytecodes::_idiv:
1469 case Bytecodes::_fdiv:
1470 case Bytecodes::_irem:
1471 case Bytecodes::_frem:
1472 case Bytecodes::_ishl:
1473 case Bytecodes::_ishr:
1474 case Bytecodes::_iushr:
1475 case Bytecodes::_iand:
1476 case Bytecodes::_ior:
1477 case Bytecodes::_ixor:
1478 case Bytecodes::_l2f:
1479 case Bytecodes::_l2i:
1480 case Bytecodes::_d2f:
1481 case Bytecodes::_d2i:
1482 case Bytecodes::_fcmpl:
1483 case Bytecodes::_fcmpg: pp(vvCTS, vCTS); break;
1484
1485 case Bytecodes::_ladd:
1486 case Bytecodes::_dadd:
1487 case Bytecodes::_lsub:
1488 case Bytecodes::_dsub:
1489 case Bytecodes::_lmul:
1490 case Bytecodes::_dmul:
1491 case Bytecodes::_ldiv:
1492 case Bytecodes::_ddiv:
1493 case Bytecodes::_lrem:
1494 case Bytecodes::_drem:
1495 case Bytecodes::_land:
1496 case Bytecodes::_lor:
1497 case Bytecodes::_lxor: pp(vvvvCTS, vvCTS); break;
1498
1499 case Bytecodes::_ineg:
1500 case Bytecodes::_fneg:
1501 case Bytecodes::_i2f:
1502 case Bytecodes::_f2i:
1503 case Bytecodes::_i2c:
1504 case Bytecodes::_i2s:
1505 case Bytecodes::_i2b: pp(vCTS, vCTS); break;
1506
1507 case Bytecodes::_lneg:
1508 case Bytecodes::_dneg:
1509 case Bytecodes::_l2d:
1510 case Bytecodes::_d2l: pp(vvCTS, vvCTS); break;
1511
1512 case Bytecodes::_lshl:
1513 case Bytecodes::_lshr:
1514 case Bytecodes::_lushr: pp(vvvCTS, vvCTS); break;
1515
1516 case Bytecodes::_i2l:
1517 case Bytecodes::_i2d:
1518 case Bytecodes::_f2l:
1519 case Bytecodes::_f2d: pp(vCTS, vvCTS); break;
1520
1521 case Bytecodes::_lcmp: pp(vvvvCTS, vCTS); break;
1522 case Bytecodes::_dcmpl:
1523 case Bytecodes::_dcmpg: pp(vvvvCTS, vCTS); break;
1524
1525 case Bytecodes::_ifeq:
1526 case Bytecodes::_ifne:
1527 case Bytecodes::_iflt:
1528 case Bytecodes::_ifge:
1529 case Bytecodes::_ifgt:
1530 case Bytecodes::_ifle:
1531 case Bytecodes::_tableswitch: ppop1(valCTS);
1532 break;
1533 case Bytecodes::_ireturn:
1534 case Bytecodes::_freturn: do_return_monitor_check();
1535 ppop1(valCTS);
1536 break;
1537 case Bytecodes::_if_icmpeq:
1538 case Bytecodes::_if_icmpne:
1539 case Bytecodes::_if_icmplt:
1540 case Bytecodes::_if_icmpge:
1541 case Bytecodes::_if_icmpgt:
1542 case Bytecodes::_if_icmple: ppop(vvCTS);
1543 break;
1544
1545 case Bytecodes::_lreturn: do_return_monitor_check();
1546 ppop(vvCTS);
1547 break;
1548
1549 case Bytecodes::_dreturn: do_return_monitor_check();
1550 ppop(vvCTS);
1551 break;
1552
1553 case Bytecodes::_if_acmpeq:
1554 case Bytecodes::_if_acmpne: ppop(rrCTS); break;
1555
1556 case Bytecodes::_jsr: do_jsr(itr->dest()); break;
1557 case Bytecodes::_jsr_w: do_jsr(itr->dest_w()); break;
1558
1559 case Bytecodes::_getstatic: do_field(true, true, itr->get_index_u2_cpcache(), itr->bci()); break;
1560 case Bytecodes::_putstatic: do_field(false, true, itr->get_index_u2_cpcache(), itr->bci()); break;
1561 case Bytecodes::_getfield: do_field(true, false, itr->get_index_u2_cpcache(), itr->bci()); break;
1562 case Bytecodes::_putfield: do_field(false, false, itr->get_index_u2_cpcache(), itr->bci()); break;
1563
1564 case Bytecodes::_invokevirtual:
1565 case Bytecodes::_invokespecial: do_method(false, false, itr->get_index_u2_cpcache(), itr->bci()); break;
1566 case Bytecodes::_invokestatic: do_method(true, false, itr->get_index_u2_cpcache(), itr->bci()); break;
1567 case Bytecodes::_invokedynamic: do_method(true, false, itr->get_index_u4(), itr->bci()); break;
1568 case Bytecodes::_invokeinterface: do_method(false, true, itr->get_index_u2_cpcache(), itr->bci()); break;
1569 case Bytecodes::_newarray:
1570 case Bytecodes::_anewarray: pp_new_ref(vCTS, itr->bci()); break;
1571 case Bytecodes::_checkcast: do_checkcast(); break;
1572 case Bytecodes::_arraylength:
1573 case Bytecodes::_instanceof: pp(rCTS, vCTS); break;
1574 case Bytecodes::_monitorenter: do_monitorenter(itr->bci()); break;
1575 case Bytecodes::_monitorexit: do_monitorexit(itr->bci()); break;
1576
1577 case Bytecodes::_athrow: // handled by do_exception_edge() BUT ...
1578 // vlh(apple): do_exception_edge() does not get
1579 // called if method has no exception handlers
1580 if ((!_has_exceptions) && (_monitor_top > 0)) {
1581 _monitor_safe = false;
1582 }
1583 break;
1584
1585 case Bytecodes::_areturn: do_return_monitor_check();
1586 ppop1(refCTS);
1587 break;
1588 case Bytecodes::_ifnull:
1589 case Bytecodes::_ifnonnull: ppop1(refCTS); break;
1590 case Bytecodes::_multianewarray: do_multianewarray(*(itr->bcp()+3), itr->bci()); break;
1591
1592 case Bytecodes::_wide: fatal("Iterator should skip this bytecode"); break;
1593 case Bytecodes::_ret: break;
1594
1595 // Java opcodes
1596 case Bytecodes::_lookupswitch: ppop1(valCTS); break;
1597
1598 default:
1599 tty->print("unexpected opcode: %d\n", itr->code());
1600 ShouldNotReachHere();
1601 break;
1602 }
1603 }
1604
1605 void GenerateOopMap::check_type(CellTypeState expected, CellTypeState actual) {
1606 if (!expected.equal_kind(actual)) {
1607 verify_error("wrong type on stack (found: %c expected: %c)", actual.to_char(), expected.to_char());
1608 }
1609 }
1610
1611 void GenerateOopMap::ppstore(CellTypeState *in, int loc_no) {
1612 while(!(*in).is_bottom()) {
1613 CellTypeState expected =*in++;
1614 CellTypeState actual = pop();
1615 check_type(expected, actual);
1616 assert(loc_no >= 0, "sanity check");
1617 set_var(loc_no++, actual);
1618 }
1619 }
1620
1621 void GenerateOopMap::ppload(CellTypeState *out, int loc_no) {
1622 while(!(*out).is_bottom()) {
1623 CellTypeState out1 = *out++;
1624 CellTypeState vcts = get_var(loc_no);
1625 assert(out1.can_be_reference() || out1.can_be_value(),
1626 "can only load refs. and values.");
1627 if (out1.is_reference()) {
1628 assert(loc_no>=0, "sanity check");
1629 if (!vcts.is_reference()) {
1630 // We were asked to push a reference, but the type of the
1631 // variable can be something else
1632 _conflict = true;
1633 if (vcts.can_be_uninit()) {
1634 // It is a ref-uninit conflict (at least). If there are other
1635 // problems, we'll get them in the next round
1636 add_to_ref_init_set(loc_no);
1637 vcts = out1;
1638 } else {
1639 // It wasn't a ref-uninit conflict. So must be a
1640 // ref-val or ref-pc conflict. Split the variable.
1641 record_refval_conflict(loc_no);
1642 vcts = out1;
1643 }
1644 push(out1); // recover...
1645 } else {
1646 push(vcts); // preserve reference.
1647 }
1648 // Otherwise it is a conflict, but one that verification would
1649 // have caught if illegal. In particular, it can't be a topCTS
1650 // resulting from mergeing two difference pcCTS's since the verifier
1651 // would have rejected any use of such a merge.
1652 } else {
1653 push(out1); // handle val/init conflict
1654 }
1655 loc_no++;
1656 }
1657 }
1658
1659 void GenerateOopMap::ppdupswap(int poplen, const char *out) {
1660 CellTypeState actual[5];
1661 assert(poplen < 5, "this must be less than length of actual vector");
1662
1663 // pop all arguments
1664 for(int i = 0; i < poplen; i++) actual[i] = pop();
1665
1666 // put them back
1667 char push_ch = *out++;
1668 while (push_ch != '\0') {
1669 int idx = push_ch - '1';
1670 assert(idx >= 0 && idx < poplen, "wrong arguments");
1671 push(actual[idx]);
1672 push_ch = *out++;
1673 }
1674 }
1675
1676 void GenerateOopMap::ppop1(CellTypeState out) {
1677 CellTypeState actual = pop();
1678 check_type(out, actual);
1679 }
1680
1681 void GenerateOopMap::ppop(CellTypeState *out) {
1682 while (!(*out).is_bottom()) {
1683 ppop1(*out++);
1684 }
1685 }
1686
1687 void GenerateOopMap::ppush1(CellTypeState in) {
1688 assert(in.is_reference() | in.is_value(), "sanity check");
1689 push(in);
1690 }
1691
1692 void GenerateOopMap::ppush(CellTypeState *in) {
1693 while (!(*in).is_bottom()) {
1694 ppush1(*in++);
1695 }
1696 }
1697
1698 void GenerateOopMap::pp(CellTypeState *in, CellTypeState *out) {
1699 ppop(in);
1700 ppush(out);
1701 }
1702
1703 void GenerateOopMap::pp_new_ref(CellTypeState *in, int bci) {
1704 ppop(in);
1705 ppush1(CellTypeState::make_line_ref(bci));
1706 }
1707
1708 void GenerateOopMap::ppop_any(int poplen) {
1709 if (_stack_top >= poplen) {
1710 _stack_top -= poplen;
1711 } else {
1712 verify_error("stack underflow");
1713 }
1714 }
1715
1716 // Replace all occurences of the state 'match' with the state 'replace'
1717 // in our current state vector.
1718 void GenerateOopMap::replace_all_CTS_matches(CellTypeState match,
1719 CellTypeState replace) {
1720 int i;
1721 int len = _max_locals + _stack_top;
1722 bool change = false;
1723
1724 for (i = len - 1; i >= 0; i--) {
1725 if (match.equal(_state[i])) {
1726 _state[i] = replace;
1727 }
1728 }
1729
1730 if (_monitor_top > 0) {
1731 int base = _max_locals + _max_stack;
1732 len = base + _monitor_top;
1733 for (i = len - 1; i >= base; i--) {
1734 if (match.equal(_state[i])) {
1735 _state[i] = replace;
1736 }
1737 }
1738 }
1739 }
1740
1741 void GenerateOopMap::do_checkcast() {
1742 CellTypeState actual = pop();
1743 check_type(refCTS, actual);
1744 push(actual);
1745 }
1746
1747 void GenerateOopMap::do_monitorenter(int bci) {
1748 CellTypeState actual = pop();
1749 if (_monitor_top == bad_monitors) {
1750 return;
1751 }
1752
1753 // Bail out when we get repeated locks on an identical monitor. This case
1754 // isn't too hard to handle and can be made to work if supporting nested
1755 // redundant synchronized statements becomes a priority.
1756 //
1757 // See also "Note" in do_monitorexit(), below.
1758 if (actual.is_lock_reference()) {
1759 _monitor_top = bad_monitors;
1760 _monitor_safe = false;
1761
1762 if (TraceMonitorMismatch) {
1763 report_monitor_mismatch("nested redundant lock -- bailout...");
1764 }
1765 return;
1766 }
1767
1768 CellTypeState lock = CellTypeState::make_lock_ref(bci);
1769 check_type(refCTS, actual);
1770 if (!actual.is_info_top()) {
1771 replace_all_CTS_matches(actual, lock);
1772 monitor_push(lock);
1773 }
1774 }
1775
1776 void GenerateOopMap::do_monitorexit(int bci) {
1777 CellTypeState actual = pop();
1778 if (_monitor_top == bad_monitors) {
1779 return;
1780 }
1781 check_type(refCTS, actual);
1782 CellTypeState expected = monitor_pop();
1783 if (!actual.is_lock_reference() || !expected.equal(actual)) {
1784 // The monitor we are exiting is not verifiably the one
1785 // on the top of our monitor stack. This causes a monitor
1786 // mismatch.
1787 _monitor_top = bad_monitors;
1788 _monitor_safe = false;
1789
1790 // We need to mark this basic block as changed so that
1791 // this monitorexit will be visited again. We need to
1792 // do this to ensure that we have accounted for the
1793 // possibility that this bytecode will throw an
1794 // exception.
1795 BasicBlock* bb = get_basic_block_containing(bci);
1796 bb->set_changed(true);
1797 bb->_monitor_top = bad_monitors;
1798
1799 if (TraceMonitorMismatch) {
1800 report_monitor_mismatch("improper monitor pair");
1801 }
1802 } else {
1803 // This code is a fix for the case where we have repeated
1804 // locking of the same object in straightline code. We clear
1805 // out the lock when it is popped from the monitor stack
1806 // and replace it with an unobtrusive reference value that can
1807 // be locked again.
1808 //
1809 // Note: when generateOopMap is fixed to properly handle repeated,
1810 // nested, redundant locks on the same object, then this
1811 // fix will need to be removed at that time.
1812 replace_all_CTS_matches(actual, CellTypeState::make_line_ref(bci));
1813 }
1814 }
1815
1816 void GenerateOopMap::do_return_monitor_check() {
1817 if (_monitor_top > 0) {
1818 // The monitor stack must be empty when we leave the method
1819 // for the monitors to be properly matched.
1820 _monitor_safe = false;
1821
1822 // Since there are no successors to the *return bytecode, it
1823 // isn't necessary to set _monitor_top to bad_monitors.
1824
1825 if (TraceMonitorMismatch) {
1826 report_monitor_mismatch("non-empty monitor stack at return");
1827 }
1828 }
1829 }
1830
1831 void GenerateOopMap::do_jsr(int targ_bci) {
1832 push(CellTypeState::make_addr(targ_bci));
1833 }
1834
1835
1836
1837 void GenerateOopMap::do_ldc(int bci) {
1838 Bytecode_loadconstant ldc(method(), bci);
1839 constantPoolOop cp = method()->constants();
1840 BasicType bt = ldc.result_type();
1841 CellTypeState cts = (bt == T_OBJECT) ? CellTypeState::make_line_ref(bci) : valCTS;
1842 // Make sure bt==T_OBJECT is the same as old code (is_pointer_entry).
1843 // Note that CONSTANT_MethodHandle entries are u2 index pairs, not pointer-entries,
1844 // and they are processed by _fast_aldc and the CP cache.
1845 assert((ldc.has_cache_index() || cp->is_object_entry(ldc.pool_index()))
1846 ? (bt == T_OBJECT) : true, "expected object type");
1847 ppush1(cts);
1848 }
1849
1850 void GenerateOopMap::do_multianewarray(int dims, int bci) {
1851 assert(dims >= 1, "sanity check");
1852 for(int i = dims -1; i >=0; i--) {
1853 ppop1(valCTS);
1854 }
1855 ppush1(CellTypeState::make_line_ref(bci));
1856 }
1857
1858 void GenerateOopMap::do_astore(int idx) {
1859 CellTypeState r_or_p = pop();
1860 if (!r_or_p.is_address() && !r_or_p.is_reference()) {
1861 // We actually expected ref or pc, but we only report that we expected a ref. It does not
1862 // really matter (at least for now)
1863 verify_error("wrong type on stack (found: %c, expected: {pr})", r_or_p.to_char());
1864 return;
1865 }
1866 set_var(idx, r_or_p);
1867 }
1868
1869 // Copies bottom/zero terminated CTS string from "src" into "dst".
1870 // Does NOT terminate with a bottom. Returns the number of cells copied.
1871 int GenerateOopMap::copy_cts(CellTypeState *dst, CellTypeState *src) {
1872 int idx = 0;
1873 while (!src[idx].is_bottom()) {
1874 dst[idx] = src[idx];
1875 idx++;
1876 }
1877 return idx;
1878 }
1879
1880 void GenerateOopMap::do_field(int is_get, int is_static, int idx, int bci) {
1881 // Dig up signature for field in constant pool
1882 constantPoolOop cp = method()->constants();
1883 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
1884 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1885 Symbol* signature = cp->symbol_at(signatureIdx);
1886
1887 // Parse signature (espcially simple for fields)
1888 assert(signature->utf8_length() > 0, "field signatures cannot have zero length");
1889 // The signature is UFT8 encoded, but the first char is always ASCII for signatures.
1890 char sigch = (char)*(signature->base());
1891 CellTypeState temp[4];
1892 CellTypeState *eff = sigchar_to_effect(sigch, bci, temp);
1893
1894 CellTypeState in[4];
1895 CellTypeState *out;
1896 int i = 0;
1897
1898 if (is_get) {
1899 out = eff;
1900 } else {
1901 out = epsilonCTS;
1902 i = copy_cts(in, eff);
1903 }
1904 if (!is_static) in[i++] = CellTypeState::ref;
1905 in[i] = CellTypeState::bottom;
1906 assert(i<=3, "sanity check");
1907 pp(in, out);
1908 }
1909
1910 void GenerateOopMap::do_method(int is_static, int is_interface, int idx, int bci) {
1911 // Dig up signature for field in constant pool
1912 constantPoolOop cp = _method->constants();
1913 Symbol* signature = cp->signature_ref_at(idx);
1914
1915 // Parse method signature
1916 CellTypeState out[4];
1917 CellTypeState in[MAXARGSIZE+1]; // Includes result
1918 ComputeCallStack cse(signature);
1919
1920 // Compute return type
1921 int res_length= cse.compute_for_returntype(out);
1922
1923 // Temporary hack.
1924 if (out[0].equal(CellTypeState::ref) && out[1].equal(CellTypeState::bottom)) {
1925 out[0] = CellTypeState::make_line_ref(bci);
1926 }
1927
1928 assert(res_length<=4, "max value should be vv");
1929
1930 // Compute arguments
1931 int arg_length = cse.compute_for_parameters(is_static != 0, in);
1932 assert(arg_length<=MAXARGSIZE, "too many locals");
1933
1934 // Pop arguments
1935 for (int i = arg_length - 1; i >= 0; i--) ppop1(in[i]);// Do args in reverse order.
1936
1937 // Report results
1938 if (_report_result_for_send == true) {
1939 fill_stackmap_for_opcodes(_itr_send, vars(), stack(), _stack_top);
1940 _report_result_for_send = false;
1941 }
1942
1943 // Push return address
1944 ppush(out);
1945 }
1946
1947 // This is used to parse the signature for fields, since they are very simple...
1948 CellTypeState *GenerateOopMap::sigchar_to_effect(char sigch, int bci, CellTypeState *out) {
1949 // Object and array
1950 if (sigch=='L' || sigch=='[') {
1951 out[0] = CellTypeState::make_line_ref(bci);
1952 out[1] = CellTypeState::bottom;
1953 return out;
1954 }
1955 if (sigch == 'J' || sigch == 'D' ) return vvCTS; // Long and Double
1956 if (sigch == 'V' ) return epsilonCTS; // Void
1957 return vCTS; // Otherwise
1958 }
1959
1960 long GenerateOopMap::_total_byte_count = 0;
1961 elapsedTimer GenerateOopMap::_total_oopmap_time;
1962
1963 // This function assumes "bcs" is at a "ret" instruction and that the vars
1964 // state is valid for that instruction. Furthermore, the ret instruction
1965 // must be the last instruction in "bb" (we store information about the
1966 // "ret" in "bb").
1967 void GenerateOopMap::ret_jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int varNo, int *data) {
1968 CellTypeState ra = vars()[varNo];
1969 if (!ra.is_good_address()) {
1970 verify_error("ret returns from two jsr subroutines?");
1971 return;
1972 }
1973 int target = ra.get_info();
1974
1975 RetTableEntry* rtEnt = _rt.find_jsrs_for_target(target);
1976 int bci = bcs->bci();
1977 for (int i = 0; i < rtEnt->nof_jsrs(); i++) {
1978 int target_bci = rtEnt->jsrs(i);
1979 // Make sure a jrtRet does not set the changed bit for dead basicblock.
1980 BasicBlock* jsr_bb = get_basic_block_containing(target_bci - 1);
1981 debug_only(BasicBlock* target_bb = &jsr_bb[1];)
1982 assert(target_bb == get_basic_block_at(target_bci), "wrong calc. of successor basicblock");
1983 bool alive = jsr_bb->is_alive();
1984 if (TraceNewOopMapGeneration) {
1985 tty->print("pc = %d, ret -> %d alive: %s\n", bci, target_bci, alive ? "true" : "false");
1986 }
1987 if (alive) jmpFct(this, target_bci, data);
1988 }
1989 }
1990
1991 //
1992 // Debug method
1993 //
1994 char* GenerateOopMap::state_vec_to_string(CellTypeState* vec, int len) {
1995 #ifdef ASSERT
1996 int checklen = MAX3(_max_locals, _max_stack, _max_monitors) + 1;
1997 assert(len < checklen, "state_vec_buf overflow");
1998 #endif
1999 for (int i = 0; i < len; i++) _state_vec_buf[i] = vec[i].to_char();
2000 _state_vec_buf[len] = 0;
2001 return _state_vec_buf;
2002 }
2003
2004 void GenerateOopMap::print_time() {
2005 tty->print_cr ("Accumulated oopmap times:");
2006 tty->print_cr ("---------------------------");
2007 tty->print_cr (" Total : %3.3f sec.", GenerateOopMap::_total_oopmap_time.seconds());
2008 tty->print_cr (" (%3.0f bytecodes per sec) ",
2009 GenerateOopMap::_total_byte_count / GenerateOopMap::_total_oopmap_time.seconds());
2010 }
2011
2012 //
2013 // ============ Main Entry Point ===========
2014 //
2015 GenerateOopMap::GenerateOopMap(methodHandle method) {
2016 // We have to initialize all variables here, that can be queried directly
2017 _method = method;
2018 _max_locals=0;
2019 _init_vars = NULL;
2020
2021 #ifndef PRODUCT
2022 // If we are doing a detailed trace, include the regular trace information.
2023 if (TraceNewOopMapGenerationDetailed) {
2024 TraceNewOopMapGeneration = true;
2025 }
2026 #endif
2027 }
2028
2029 void GenerateOopMap::compute_map(TRAPS) {
2030 #ifndef PRODUCT
2031 if (TimeOopMap2) {
2032 method()->print_short_name(tty);
2033 tty->print(" ");
2034 }
2035 if (TimeOopMap) {
2036 _total_byte_count += method()->code_size();
2037 }
2038 #endif
2039 TraceTime t_single("oopmap time", TimeOopMap2);
2040 TraceTime t_all(NULL, &_total_oopmap_time, TimeOopMap);
2041
2042 // Initialize values
2043 _got_error = false;
2044 _conflict = false;
2045 _max_locals = method()->max_locals();
2046 _max_stack = method()->max_stack();
2047 _has_exceptions = (method()->exception_table()->length() > 0);
2048 _nof_refval_conflicts = 0;
2049 _init_vars = new GrowableArray<intptr_t>(5); // There are seldom more than 5 init_vars
2050 _report_result = false;
2051 _report_result_for_send = false;
2052 _new_var_map = NULL;
2053 _ret_adr_tos = new GrowableArray<intptr_t>(5); // 5 seems like a good number;
2054 _did_rewriting = false;
2055 _did_relocation = false;
2056
2057 if (TraceNewOopMapGeneration) {
2058 tty->print("Method name: %s\n", method()->name()->as_C_string());
2059 if (Verbose) {
2060 _method->print_codes();
2061 tty->print_cr("Exception table:");
2062 typeArrayOop excps = method()->exception_table();
2063 for(int i = 0; i < excps->length(); i += 4) {
2064 tty->print_cr("[%d - %d] -> %d", excps->int_at(i + 0), excps->int_at(i + 1), excps->int_at(i + 2));
2065 }
2066 }
2067 }
2068
2069 // if no code - do nothing
2070 // compiler needs info
2071 if (method()->code_size() == 0 || _max_locals + method()->max_stack() == 0) {
2072 fill_stackmap_prolog(0);
2073 fill_stackmap_epilog();
2074 return;
2075 }
2076 // Step 1: Compute all jump targets and their return value
2077 if (!_got_error)
2078 _rt.compute_ret_table(_method);
2079
2080 // Step 2: Find all basic blocks and count GC points
2081 if (!_got_error)
2082 mark_bbheaders_and_count_gc_points();
2083
2084 // Step 3: Calculate stack maps
2085 if (!_got_error)
2086 do_interpretation();
2087
2088 // Step 4:Return results
2089 if (!_got_error && report_results())
2090 report_result();
2091
2092 if (_got_error) {
2093 THROW_HANDLE(_exception);
2094 }
2095 }
2096
2097 // Error handling methods
2098 // These methods create an exception for the current thread which is thrown
2099 // at the bottom of the call stack, when it returns to compute_map(). The
2100 // _got_error flag controls execution. NOT TODO: The VM exception propagation
2101 // mechanism using TRAPS/CHECKs could be used here instead but it would need
2102 // to be added as a parameter to every function and checked for every call.
2103 // The tons of extra code it would generate didn't seem worth the change.
2104 //
2105 void GenerateOopMap::error_work(const char *format, va_list ap) {
2106 _got_error = true;
2107 char msg_buffer[512];
2108 vsnprintf(msg_buffer, sizeof(msg_buffer), format, ap);
2109 // Append method name
2110 char msg_buffer2[512];
2111 jio_snprintf(msg_buffer2, sizeof(msg_buffer2), "%s in method %s", msg_buffer, method()->name()->as_C_string());
2112 _exception = Exceptions::new_exception(Thread::current(),
2113 vmSymbols::java_lang_LinkageError(), msg_buffer2);
2114 }
2115
2116 void GenerateOopMap::report_error(const char *format, ...) {
2117 va_list ap;
2118 va_start(ap, format);
2119 error_work(format, ap);
2120 }
2121
2122 void GenerateOopMap::verify_error(const char *format, ...) {
2123 // We do not distinguish between different types of errors for verification
2124 // errors. Let the verifier give a better message.
2125 const char *msg = "Illegal class file encountered. Try running with -Xverify:all";
2126 _got_error = true;
2127 // Append method name
2128 char msg_buffer2[512];
2129 jio_snprintf(msg_buffer2, sizeof(msg_buffer2), "%s in method %s", msg,
2130 method()->name()->as_C_string());
2131 _exception = Exceptions::new_exception(Thread::current(),
2132 vmSymbols::java_lang_LinkageError(), msg_buffer2);
2133 }
2134
2135 //
2136 // Report result opcodes
2137 //
2138 void GenerateOopMap::report_result() {
2139
2140 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass");
2141
2142 // We now want to report the result of the parse
2143 _report_result = true;
2144
2145 // Prolog code
2146 fill_stackmap_prolog(_gc_points);
2147
2148 // Mark everything changed, then do one interpretation pass.
2149 for (int i = 0; i<_bb_count; i++) {
2150 if (_basic_blocks[i].is_reachable()) {
2151 _basic_blocks[i].set_changed(true);
2152 interp_bb(&_basic_blocks[i]);
2153 }
2154 }
2155
2156 // Note: Since we are skipping dead-code when we are reporting results, then
2157 // the no. of encountered gc-points might be fewer than the previously number
2158 // we have counted. (dead-code is a pain - it should be removed before we get here)
2159 fill_stackmap_epilog();
2160
2161 // Report initvars
2162 fill_init_vars(_init_vars);
2163
2164 _report_result = false;
2165 }
2166
2167 void GenerateOopMap::result_for_basicblock(int bci) {
2168 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass for basicblock");
2169
2170 // We now want to report the result of the parse
2171 _report_result = true;
2172
2173 // Find basicblock and report results
2174 BasicBlock* bb = get_basic_block_containing(bci);
2175 assert(bb->is_reachable(), "getting result from unreachable basicblock");
2176 bb->set_changed(true);
2177 interp_bb(bb);
2178 }
2179
2180 //
2181 // Conflict handling code
2182 //
2183
2184 void GenerateOopMap::record_refval_conflict(int varNo) {
2185 assert(varNo>=0 && varNo< _max_locals, "index out of range");
2186
2187 if (TraceOopMapRewrites) {
2188 tty->print("### Conflict detected (local no: %d)\n", varNo);
2189 }
2190
2191 if (!_new_var_map) {
2192 _new_var_map = NEW_RESOURCE_ARRAY(int, _max_locals);
2193 for (int k = 0; k < _max_locals; k++) _new_var_map[k] = k;
2194 }
2195
2196 if ( _new_var_map[varNo] == varNo) {
2197 // Check if max. number of locals has been reached
2198 if (_max_locals + _nof_refval_conflicts >= MAX_LOCAL_VARS) {
2199 report_error("Rewriting exceeded local variable limit");
2200 return;
2201 }
2202 _new_var_map[varNo] = _max_locals + _nof_refval_conflicts;
2203 _nof_refval_conflicts++;
2204 }
2205 }
2206
2207 void GenerateOopMap::rewrite_refval_conflicts()
2208 {
2209 // We can get here two ways: Either a rewrite conflict was detected, or
2210 // an uninitialize reference was detected. In the second case, we do not
2211 // do any rewriting, we just want to recompute the reference set with the
2212 // new information
2213
2214 int nof_conflicts = 0; // Used for debugging only
2215
2216 if ( _nof_refval_conflicts == 0 )
2217 return;
2218
2219 // Check if rewrites are allowed in this parse.
2220 if (!allow_rewrites() && !IgnoreRewrites) {
2221 fatal("Rewriting method not allowed at this stage");
2222 }
2223
2224
2225 // This following flag is to tempoary supress rewrites. The locals that might conflict will
2226 // all be set to contain values. This is UNSAFE - however, until the rewriting has been completely
2227 // tested it is nice to have.
2228 if (IgnoreRewrites) {
2229 if (Verbose) {
2230 tty->print("rewrites suppressed for local no. ");
2231 for (int l = 0; l < _max_locals; l++) {
2232 if (_new_var_map[l] != l) {
2233 tty->print("%d ", l);
2234 vars()[l] = CellTypeState::value;
2235 }
2236 }
2237 tty->cr();
2238 }
2239
2240 // That was that...
2241 _new_var_map = NULL;
2242 _nof_refval_conflicts = 0;
2243 _conflict = false;
2244
2245 return;
2246 }
2247
2248 // Tracing flag
2249 _did_rewriting = true;
2250
2251 if (TraceOopMapRewrites) {
2252 tty->print_cr("ref/value conflict for method %s - bytecodes are getting rewritten", method()->name()->as_C_string());
2253 method()->print();
2254 method()->print_codes();
2255 }
2256
2257 assert(_new_var_map!=NULL, "nothing to rewrite");
2258 assert(_conflict==true, "We should not be here");
2259
2260 compute_ret_adr_at_TOS();
2261 if (!_got_error) {
2262 for (int k = 0; k < _max_locals && !_got_error; k++) {
2263 if (_new_var_map[k] != k) {
2264 if (TraceOopMapRewrites) {
2265 tty->print_cr("Rewriting: %d -> %d", k, _new_var_map[k]);
2266 }
2267 rewrite_refval_conflict(k, _new_var_map[k]);
2268 if (_got_error) return;
2269 nof_conflicts++;
2270 }
2271 }
2272 }
2273
2274 assert(nof_conflicts == _nof_refval_conflicts, "sanity check");
2275
2276 // Adjust the number of locals
2277 method()->set_max_locals(_max_locals+_nof_refval_conflicts);
2278 _max_locals += _nof_refval_conflicts;
2279
2280 // That was that...
2281 _new_var_map = NULL;
2282 _nof_refval_conflicts = 0;
2283 }
2284
2285 void GenerateOopMap::rewrite_refval_conflict(int from, int to) {
2286 bool startOver;
2287 do {
2288 // Make sure that the BytecodeStream is constructed in the loop, since
2289 // during rewriting a new method oop is going to be used, and the next time
2290 // around we want to use that.
2291 BytecodeStream bcs(_method);
2292 startOver = false;
2293
2294 while( bcs.next() >=0 && !startOver && !_got_error) {
2295 startOver = rewrite_refval_conflict_inst(&bcs, from, to);
2296 }
2297 } while (startOver && !_got_error);
2298 }
2299
2300 /* If the current instruction is one that uses local variable "from"
2301 in a ref way, change it to use "to". There's a subtle reason why we
2302 renumber the ref uses and not the non-ref uses: non-ref uses may be
2303 2 slots wide (double, long) which would necessitate keeping track of
2304 whether we should add one or two variables to the method. If the change
2305 affected the width of some instruction, returns "TRUE"; otherwise, returns "FALSE".
2306 Another reason for moving ref's value is for solving (addr, ref) conflicts, which
2307 both uses aload/astore methods.
2308 */
2309 bool GenerateOopMap::rewrite_refval_conflict_inst(BytecodeStream *itr, int from, int to) {
2310 Bytecodes::Code bc = itr->code();
2311 int index;
2312 int bci = itr->bci();
2313
2314 if (is_aload(itr, &index) && index == from) {
2315 if (TraceOopMapRewrites) {
2316 tty->print_cr("Rewriting aload at bci: %d", bci);
2317 }
2318 return rewrite_load_or_store(itr, Bytecodes::_aload, Bytecodes::_aload_0, to);
2319 }
2320
2321 if (is_astore(itr, &index) && index == from) {
2322 if (!stack_top_holds_ret_addr(bci)) {
2323 if (TraceOopMapRewrites) {
2324 tty->print_cr("Rewriting astore at bci: %d", bci);
2325 }
2326 return rewrite_load_or_store(itr, Bytecodes::_astore, Bytecodes::_astore_0, to);
2327 } else {
2328 if (TraceOopMapRewrites) {
2329 tty->print_cr("Supress rewriting of astore at bci: %d", bci);
2330 }
2331 }
2332 }
2333
2334 return false;
2335 }
2336
2337 // The argument to this method is:
2338 // bc : Current bytecode
2339 // bcN : either _aload or _astore
2340 // bc0 : either _aload_0 or _astore_0
2341 bool GenerateOopMap::rewrite_load_or_store(BytecodeStream *bcs, Bytecodes::Code bcN, Bytecodes::Code bc0, unsigned int varNo) {
2342 assert(bcN == Bytecodes::_astore || bcN == Bytecodes::_aload, "wrong argument (bcN)");
2343 assert(bc0 == Bytecodes::_astore_0 || bc0 == Bytecodes::_aload_0, "wrong argument (bc0)");
2344 int ilen = Bytecodes::length_at(_method(), bcs->bcp());
2345 int newIlen;
2346
2347 if (ilen == 4) {
2348 // Original instruction was wide; keep it wide for simplicity
2349 newIlen = 4;
2350 } else if (varNo < 4)
2351 newIlen = 1;
2352 else if (varNo >= 256)
2353 newIlen = 4;
2354 else
2355 newIlen = 2;
2356
2357 // If we need to relocate in order to patch the byte, we
2358 // do the patching in a temp. buffer, that is passed to the reloc.
2359 // The patching of the bytecode stream is then done by the Relocator.
2360 // This is neccesary, since relocating the instruction at a certain bci, might
2361 // also relocate that instruction, e.g., if a _goto before it gets widen to a _goto_w.
2362 // Hence, we do not know which bci to patch after relocation.
2363
2364 assert(newIlen <= 4, "sanity check");
2365 u_char inst_buffer[4]; // Max. instruction size is 4.
2366 address bcp;
2367
2368 if (newIlen != ilen) {
2369 // Relocation needed do patching in temp. buffer
2370 bcp = (address)inst_buffer;
2371 } else {
2372 bcp = _method->bcp_from(bcs->bci());
2373 }
2374
2375 // Patch either directly in methodOop or in temp. buffer
2376 if (newIlen == 1) {
2377 assert(varNo < 4, "varNo too large");
2378 *bcp = bc0 + varNo;
2379 } else if (newIlen == 2) {
2380 assert(varNo < 256, "2-byte index needed!");
2381 *(bcp + 0) = bcN;
2382 *(bcp + 1) = varNo;
2383 } else {
2384 assert(newIlen == 4, "Wrong instruction length");
2385 *(bcp + 0) = Bytecodes::_wide;
2386 *(bcp + 1) = bcN;
2387 Bytes::put_Java_u2(bcp+2, varNo);
2388 }
2389
2390 if (newIlen != ilen) {
2391 expand_current_instr(bcs->bci(), ilen, newIlen, inst_buffer);
2392 }
2393
2394
2395 return (newIlen != ilen);
2396 }
2397
2398 class RelocCallback : public RelocatorListener {
2399 private:
2400 GenerateOopMap* _gom;
2401 public:
2402 RelocCallback(GenerateOopMap* gom) { _gom = gom; };
2403
2404 // Callback method
2405 virtual void relocated(int bci, int delta, int new_code_length) {
2406 _gom->update_basic_blocks (bci, delta, new_code_length);
2407 _gom->update_ret_adr_at_TOS(bci, delta);
2408 _gom->_rt.update_ret_table (bci, delta);
2409 }
2410 };
2411
2412 // Returns true if expanding was succesful. Otherwise, reports an error and
2413 // returns false.
2414 void GenerateOopMap::expand_current_instr(int bci, int ilen, int newIlen, u_char inst_buffer[]) {
2415 Thread *THREAD = Thread::current(); // Could really have TRAPS argument.
2416 RelocCallback rcb(this);
2417 Relocator rc(_method, &rcb);
2418 methodHandle m= rc.insert_space_at(bci, newIlen, inst_buffer, THREAD);
2419 if (m.is_null() || HAS_PENDING_EXCEPTION) {
2420 report_error("could not rewrite method - exception occurred or bytecode buffer overflow");
2421 return;
2422 }
2423
2424 // Relocator returns a new method oop.
2425 _did_relocation = true;
2426 _method = m;
2427 }
2428
2429
2430 bool GenerateOopMap::is_astore(BytecodeStream *itr, int *index) {
2431 Bytecodes::Code bc = itr->code();
2432 switch(bc) {
2433 case Bytecodes::_astore_0:
2434 case Bytecodes::_astore_1:
2435 case Bytecodes::_astore_2:
2436 case Bytecodes::_astore_3:
2437 *index = bc - Bytecodes::_astore_0;
2438 return true;
2439 case Bytecodes::_astore:
2440 *index = itr->get_index();
2441 return true;
2442 }
2443 return false;
2444 }
2445
2446 bool GenerateOopMap::is_aload(BytecodeStream *itr, int *index) {
2447 Bytecodes::Code bc = itr->code();
2448 switch(bc) {
2449 case Bytecodes::_aload_0:
2450 case Bytecodes::_aload_1:
2451 case Bytecodes::_aload_2:
2452 case Bytecodes::_aload_3:
2453 *index = bc - Bytecodes::_aload_0;
2454 return true;
2455
2456 case Bytecodes::_aload:
2457 *index = itr->get_index();
2458 return true;
2459 }
2460 return false;
2461 }
2462
2463
2464 // Return true iff the top of the operand stack holds a return address at
2465 // the current instruction
2466 bool GenerateOopMap::stack_top_holds_ret_addr(int bci) {
2467 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2468 if (_ret_adr_tos->at(i) == bci)
2469 return true;
2470 }
2471
2472 return false;
2473 }
2474
2475 void GenerateOopMap::compute_ret_adr_at_TOS() {
2476 assert(_ret_adr_tos != NULL, "must be initialized");
2477 _ret_adr_tos->clear();
2478
2479 for (int i = 0; i < bb_count(); i++) {
2480 BasicBlock* bb = &_basic_blocks[i];
2481
2482 // Make sure to only check basicblocks that are reachable
2483 if (bb->is_reachable()) {
2484
2485 // For each Basic block we check all instructions
2486 BytecodeStream bcs(_method);
2487 bcs.set_interval(bb->_bci, next_bb_start_pc(bb));
2488
2489 restore_state(bb);
2490
2491 while (bcs.next()>=0 && !_got_error) {
2492 // TDT: should this be is_good_address() ?
2493 if (_stack_top > 0 && stack()[_stack_top-1].is_address()) {
2494 _ret_adr_tos->append(bcs.bci());
2495 if (TraceNewOopMapGeneration) {
2496 tty->print_cr("Ret_adr TOS at bci: %d", bcs.bci());
2497 }
2498 }
2499 interp1(&bcs);
2500 }
2501 }
2502 }
2503 }
2504
2505 void GenerateOopMap::update_ret_adr_at_TOS(int bci, int delta) {
2506 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2507 int v = _ret_adr_tos->at(i);
2508 if (v > bci) _ret_adr_tos->at_put(i, v + delta);
2509 }
2510 }
2511
2512 // ===================================================================
2513
2514 #ifndef PRODUCT
2515 int ResolveOopMapConflicts::_nof_invocations = 0;
2516 int ResolveOopMapConflicts::_nof_rewrites = 0;
2517 int ResolveOopMapConflicts::_nof_relocations = 0;
2518 #endif
2519
2520 methodHandle ResolveOopMapConflicts::do_potential_rewrite(TRAPS) {
2521 compute_map(CHECK_(methodHandle()));
2522
2523 #ifndef PRODUCT
2524 // Tracking and statistics
2525 if (PrintRewrites) {
2526 _nof_invocations++;
2527 if (did_rewriting()) {
2528 _nof_rewrites++;
2529 if (did_relocation()) _nof_relocations++;
2530 tty->print("Method was rewritten %s: ", (did_relocation()) ? "and relocated" : "");
2531 method()->print_value(); tty->cr();
2532 tty->print_cr("Cand.: %d rewrts: %d (%d%%) reloc.: %d (%d%%)",
2533 _nof_invocations,
2534 _nof_rewrites, (_nof_rewrites * 100) / _nof_invocations,
2535 _nof_relocations, (_nof_relocations * 100) / _nof_invocations);
2536 }
2537 }
2538 #endif
2539 return methodHandle(THREAD, method());
2540 }