1 #ifdef USE_PRAGMA_IDENT_SRC
2 #pragma ident "@(#)generateOopMap.cpp 1.141 07/05/05 17:06:03 JVM"
3 #endif
4 /*
5 * Copyright 1997-2005 Sun Microsystems, Inc. All Rights Reserved.
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
7 *
8 * This code is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 only, as
10 * published by the Free Software Foundation.
11 *
12 * This code is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * version 2 for more details (a copy is included in the LICENSE file that
16 * accompanied this code).
17 *
18 * You should have received a copy of the GNU General Public License version
19 * 2 along with this work; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21 *
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
24 * have any questions.
25 *
26 */
27
28 //
29 //
30 // Compute stack layouts for each instruction in method.
31 //
32 // Problems:
33 // - What to do about jsr with different types of local vars?
34 // Need maps that are conditional on jsr path?
35 // - Jsr and exceptions should be done more efficiently (the retAddr stuff)
36 //
37 // Alternative:
38 // - Could extend verifier to provide this information.
39 // For: one fewer abstract interpreter to maintain. Against: the verifier
40 // solves a bigger problem so slower (undesirable to force verification of
41 // everything?).
42 //
43 // Algorithm:
44 // Partition bytecodes into basic blocks
45 // For each basic block: store entry state (vars, stack). For instructions
46 // inside basic blocks we do not store any state (instead we recompute it
47 // from state produced by previous instruction).
48 //
49 // Perform abstract interpretation of bytecodes over this lattice:
50 //
51 // _--'#'--_
52 // / / \ \
53 // / / \ \
54 // / | | \
55 // 'r' 'v' 'p' ' '
56 // \ | | /
57 // \ \ / /
58 // \ \ / /
59 // -- '@' --
60 //
61 // '#' top, result of conflict merge
62 // 'r' reference type
63 // 'v' value type
64 // 'p' pc type for jsr/ret
65 // ' ' uninitialized; never occurs on operand stack in Java
66 // '@' bottom/unexecuted; initial state each bytecode.
67 //
68 // Basic block headers are the only merge points. We use this iteration to
69 // compute the information:
70 //
71 // find basic blocks;
72 // initialize them with uninitialized state;
73 // initialize first BB according to method signature;
74 // mark first BB changed
75 // while (some BB is changed) do {
76 // perform abstract interpration of all bytecodes in BB;
77 // merge exit state of BB into entry state of all successor BBs,
78 // noting if any of these change;
79 // }
80 //
81 // One additional complication is necessary. The jsr instruction pushes
82 // a return PC on the stack (a 'p' type in the abstract interpretation).
83 // To be able to process "ret" bytecodes, we keep track of these return
84 // PC's in a 'retAddrs' structure in abstract interpreter context (when
85 // processing a "ret" bytecodes, it is not sufficient to know that it gets
86 // an argument of the right type 'p'; we need to know which address it
87 // returns to).
88 //
89 // (Note this comment is borrowed form the original author of the algorithm)
90
91 #include "incls/_precompiled.incl"
92 #include "incls/_generateOopMap.cpp.incl"
93
94 // ComputeCallStack
95 //
96 // Specialization of SignatureIterator - compute the effects of a call
97 //
98 class ComputeCallStack : public SignatureIterator {
99 CellTypeState *_effect;
100 int _idx;
101
102 void setup();
103 void set(CellTypeState state) { _effect[_idx++] = state; }
104 int length() { return _idx; };
105
106 virtual void do_bool () { set(CellTypeState::value); };
107 virtual void do_char () { set(CellTypeState::value); };
108 virtual void do_float () { set(CellTypeState::value); };
109 virtual void do_byte () { set(CellTypeState::value); };
110 virtual void do_short () { set(CellTypeState::value); };
111 virtual void do_int () { set(CellTypeState::value); };
112 virtual void do_void () { set(CellTypeState::bottom);};
113 virtual void do_object(int begin, int end) { set(CellTypeState::ref); };
114 virtual void do_array (int begin, int end) { set(CellTypeState::ref); };
115
116 void do_double() { set(CellTypeState::value);
117 set(CellTypeState::value); }
118 void do_long () { set(CellTypeState::value);
119 set(CellTypeState::value); }
120
121 public:
122 ComputeCallStack(symbolOop signature) : SignatureIterator(signature) {};
123
124 // Compute methods
125 int compute_for_parameters(bool is_static, CellTypeState *effect) {
126 _idx = 0;
127 _effect = effect;
128
129 if (!is_static)
130 effect[_idx++] = CellTypeState::ref;
131
132 iterate_parameters();
133
134 return length();
135 };
136
137 int compute_for_returntype(CellTypeState *effect) {
138 _idx = 0;
139 _effect = effect;
140 iterate_returntype();
141 set(CellTypeState::bottom); // Always terminate with a bottom state, so ppush works
142
143 return length();
144 }
145 };
146
147 //=========================================================================================
148 // ComputeEntryStack
149 //
150 // Specialization of SignatureIterator - in order to set up first stack frame
151 //
152 class ComputeEntryStack : public SignatureIterator {
153 CellTypeState *_effect;
154 int _idx;
155
156 void setup();
157 void set(CellTypeState state) { _effect[_idx++] = state; }
158 int length() { return _idx; };
159
160 virtual void do_bool () { set(CellTypeState::value); };
161 virtual void do_char () { set(CellTypeState::value); };
162 virtual void do_float () { set(CellTypeState::value); };
163 virtual void do_byte () { set(CellTypeState::value); };
164 virtual void do_short () { set(CellTypeState::value); };
165 virtual void do_int () { set(CellTypeState::value); };
166 virtual void do_void () { set(CellTypeState::bottom);};
167 virtual void do_object(int begin, int end) { set(CellTypeState::make_slot_ref(_idx)); }
168 virtual void do_array (int begin, int end) { set(CellTypeState::make_slot_ref(_idx)); }
169
170 void do_double() { set(CellTypeState::value);
171 set(CellTypeState::value); }
172 void do_long () { set(CellTypeState::value);
173 set(CellTypeState::value); }
174
175 public:
176 ComputeEntryStack(symbolOop signature) : SignatureIterator(signature) {};
177
178 // Compute methods
179 int compute_for_parameters(bool is_static, CellTypeState *effect) {
180 _idx = 0;
181 _effect = effect;
182
183 if (!is_static)
184 effect[_idx++] = CellTypeState::make_slot_ref(0);
185
186 iterate_parameters();
187
188 return length();
189 };
190
191 int compute_for_returntype(CellTypeState *effect) {
192 _idx = 0;
193 _effect = effect;
194 iterate_returntype();
195 set(CellTypeState::bottom); // Always terminate with a bottom state, so ppush works
196
197 return length();
198 }
199 };
200
201 //=====================================================================================
202 //
203 // Implementation of RetTable/RetTableEntry
204 //
205 // Contains function to itereate through all bytecodes
206 // and find all return entry points
207 //
208 int RetTable::_init_nof_entries = 10;
209 int RetTableEntry::_init_nof_jsrs = 5;
210
211 void RetTableEntry::add_delta(int bci, int delta) {
212 if (_target_bci > bci) _target_bci += delta;
213
214 for (int k = 0; k < _jsrs->length(); k++) {
215 int jsr = _jsrs->at(k);
216 if (jsr > bci) _jsrs->at_put(k, jsr+delta);
217 }
218 }
219
220 void RetTable::compute_ret_table(methodHandle method) {
221 BytecodeStream i(method);
222 Bytecodes::Code bytecode;
223
224 while( (bytecode = i.next()) >= 0) {
225 switch (bytecode) {
226 case Bytecodes::_jsr:
227 add_jsr(i.next_bci(), i.dest());
228 break;
229 case Bytecodes::_jsr_w:
230 add_jsr(i.next_bci(), i.dest_w());
231 break;
232 }
233 }
234 }
235
236 void RetTable::add_jsr(int return_bci, int target_bci) {
237 RetTableEntry* entry = _first;
238
239 // Scan table for entry
240 for (;entry && entry->target_bci() != target_bci; entry = entry->next());
241
242 if (!entry) {
243 // Allocate new entry and put in list
244 entry = new RetTableEntry(target_bci, _first);
245 _first = entry;
246 }
247
248 // Now "entry" is set. Make sure that the entry is initialized
249 // and has room for the new jsr.
250 entry->add_jsr(return_bci);
251 }
252
253 RetTableEntry* RetTable::find_jsrs_for_target(int targBci) {
254 RetTableEntry *cur = _first;
255
256 while(cur) {
257 assert(cur->target_bci() != -1, "sanity check");
258 if (cur->target_bci() == targBci) return cur;
259 cur = cur->next();
260 }
261 ShouldNotReachHere();
262 return NULL;
263 }
264
265 // The instruction at bci is changing size by "delta". Update the return map.
266 void RetTable::update_ret_table(int bci, int delta) {
267 RetTableEntry *cur = _first;
268 while(cur) {
269 cur->add_delta(bci, delta);
270 cur = cur->next();
271 }
272 }
273
274 //
275 // Celltype state
276 //
277
278 CellTypeState CellTypeState::bottom = CellTypeState::make_bottom();
279 CellTypeState CellTypeState::uninit = CellTypeState::make_any(uninit_value);
280 CellTypeState CellTypeState::ref = CellTypeState::make_any(ref_conflict);
281 CellTypeState CellTypeState::value = CellTypeState::make_any(val_value);
282 CellTypeState CellTypeState::refUninit = CellTypeState::make_any(ref_conflict | uninit_value);
283 CellTypeState CellTypeState::top = CellTypeState::make_top();
284 CellTypeState CellTypeState::addr = CellTypeState::make_any(addr_conflict);
285
286 // Commonly used constants
287 static CellTypeState epsilonCTS[1] = { CellTypeState::bottom };
288 static CellTypeState refCTS = CellTypeState::ref;
289 static CellTypeState valCTS = CellTypeState::value;
290 static CellTypeState vCTS[2] = { CellTypeState::value, CellTypeState::bottom };
291 static CellTypeState rCTS[2] = { CellTypeState::ref, CellTypeState::bottom };
292 static CellTypeState rrCTS[3] = { CellTypeState::ref, CellTypeState::ref, CellTypeState::bottom };
293 static CellTypeState vrCTS[3] = { CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
294 static CellTypeState vvCTS[3] = { CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
295 static CellTypeState rvrCTS[4] = { CellTypeState::ref, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
296 static CellTypeState vvrCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
297 static CellTypeState vvvCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
298 static CellTypeState vvvrCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
299 static CellTypeState vvvvCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
300
301 char CellTypeState::to_char() const {
302 if (can_be_reference()) {
303 if (can_be_value() || can_be_address())
304 return '#'; // Conflict that needs to be rewritten
305 else
306 return 'r';
307 } else if (can_be_value())
308 return 'v';
309 else if (can_be_address())
310 return 'p';
311 else if (can_be_uninit())
312 return ' ';
313 else
314 return '@';
315 }
316
317
318 // Print a detailed CellTypeState. Indicate all bits that are set. If
319 // the CellTypeState represents an address or a reference, print the
320 // value of the additional information.
321 void CellTypeState::print(outputStream *os) {
322 if (can_be_address()) {
323 os->print("(p");
324 } else {
325 os->print("( ");
326 }
327 if (can_be_reference()) {
328 os->print("r");
329 } else {
330 os->print(" ");
331 }
332 if (can_be_value()) {
333 os->print("v");
334 } else {
335 os->print(" ");
336 }
337 if (can_be_uninit()) {
338 os->print("u|");
339 } else {
340 os->print(" |");
341 }
342 if (is_info_top()) {
343 os->print("Top)");
344 } else if (is_info_bottom()) {
345 os->print("Bot)");
346 } else {
347 if (is_reference()) {
348 int info = get_info();
349 int data = info & ~(ref_not_lock_bit | ref_slot_bit);
350 if (info & ref_not_lock_bit) {
351 // Not a monitor lock reference.
352 if (info & ref_slot_bit) {
353 // slot
354 os->print("slot%d)", data);
355 } else {
356 // line
357 os->print("line%d)", data);
358 }
359 } else {
360 // lock
361 os->print("lock%d)", data);
362 }
363 } else {
364 os->print("%d)", get_info());
365 }
366 }
367 }
368
369 //
370 // Basicblock handling methods
371 //
372
373 void GenerateOopMap ::initialize_bb() {
374 _gc_points = 0;
375 _bb_count = 0;
376 int size = binsToHold(method()->code_size());
377 _bb_hdr_bits = NEW_RESOURCE_ARRAY(uintptr_t,size);
378 memset(_bb_hdr_bits, 0, size*sizeof(uintptr_t));
379 }
380
381 void GenerateOopMap ::set_bbmark_bit(int bci) {
382 int idx = bci >> LogBitsPerWord;
383 uintptr_t bit = (uintptr_t)1 << (bci & (BitsPerWord-1));
384 _bb_hdr_bits[idx] |= bit;
385 }
386
387 void GenerateOopMap ::clear_bbmark_bit(int bci) {
388 int idx = bci >> LogBitsPerWord;
389 uintptr_t bit = (uintptr_t)1 << (bci & (BitsPerWord-1));
390 _bb_hdr_bits[idx] &= (~bit);
391 }
392
393 void GenerateOopMap::bb_mark_fct(GenerateOopMap *c, int bci, int *data) {
394 assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
395 if (c->is_bb_header(bci))
396 return;
397
398 if (TraceNewOopMapGeneration) {
399 tty->print_cr("Basicblock#%d begins at: %d", c->_bb_count, bci);
400 }
401 c->set_bbmark_bit(bci);
402 c->_bb_count++;
403 }
404
405
406 void GenerateOopMap::mark_bbheaders_and_count_gc_points() {
407 initialize_bb();
408
409 bool fellThrough = false; // False to get first BB marked.
410
411 // First mark all exception handlers as start of a basic-block
412 typeArrayOop excps = method()->exception_table();
413 for(int i = 0; i < excps->length(); i += 4) {
414 int handler_pc_idx = i+2;
415 bb_mark_fct(this, excps->int_at(handler_pc_idx), NULL);
416 }
417
418 // Then iterate through the code
419 BytecodeStream bcs(_method);
420 Bytecodes::Code bytecode;
421
422 while( (bytecode = bcs.next()) >= 0) {
423 int bci = bcs.bci();
424
425 if (!fellThrough)
426 bb_mark_fct(this, bci, NULL);
427
428 fellThrough = jump_targets_do(&bcs, &GenerateOopMap::bb_mark_fct, NULL);
429
430 /* We will also mark successors of jsr's as basic block headers. */
431 switch (bytecode) {
432 case Bytecodes::_jsr:
433 assert(!fellThrough, "should not happen");
434 bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), NULL);
435 break;
436 case Bytecodes::_jsr_w:
437 assert(!fellThrough, "should not happen");
438 bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), NULL);
439 break;
440 }
441
442 if (possible_gc_point(&bcs))
443 _gc_points++;
444 }
445 }
446
447 void GenerateOopMap::reachable_basicblock(GenerateOopMap *c, int bci, int *data) {
448 assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
449 BasicBlock* bb = c->get_basic_block_at(bci);
450 if (bb->is_dead()) {
451 bb->mark_as_alive();
452 *data = 1; // Mark basicblock as changed
453 }
454 }
455
456
457 void GenerateOopMap::mark_reachable_code() {
458 int change = 1; // int to get function pointers to work
459
460 // Mark entry basic block as alive and all exception handlers
461 _basic_blocks[0].mark_as_alive();
462 typeArrayOop excps = method()->exception_table();
463 for(int i = 0; i < excps->length(); i += 4) {
464 int handler_pc_idx = i+2;
465 BasicBlock *bb = get_basic_block_at(excps->int_at(handler_pc_idx));
466 // If block is not already alive (due to multiple exception handlers to same bb), then
467 // make it alive
468 if (bb->is_dead()) bb->mark_as_alive();
469 }
470
471 BytecodeStream bcs(_method);
472
473 // Iterate through all basic blocks until we reach a fixpoint
474 while (change) {
475 change = 0;
476
477 for (int i = 0; i < _bb_count; i++) {
478 BasicBlock *bb = &_basic_blocks[i];
479 if (bb->is_alive()) {
480 // Position bytecodestream at last bytecode in basicblock
481 bcs.set_start(bb->_end_bci);
482 bcs.next();
483 Bytecodes::Code bytecode = bcs.code();
484 int bci = bcs.bci();
485 assert(bci == bb->_end_bci, "wrong bci");
486
487 bool fell_through = jump_targets_do(&bcs, &GenerateOopMap::reachable_basicblock, &change);
488
489 // We will also mark successors of jsr's as alive.
490 switch (bytecode) {
491 case Bytecodes::_jsr:
492 case Bytecodes::_jsr_w:
493 assert(!fell_through, "should not happen");
494 reachable_basicblock(this, bci + Bytecodes::length_for(bytecode), &change);
495 break;
496 }
497 if (fell_through) {
498 // Mark successor as alive
499 if (bb[1].is_dead()) {
500 bb[1].mark_as_alive();
501 change = 1;
502 }
503 }
504 }
505 }
506 }
507 }
508
509 /* If the current instruction in "c" has no effect on control flow,
510 returns "true". Otherwise, calls "jmpFct" one or more times, with
511 "c", an appropriate "pcDelta", and "data" as arguments, then
512 returns "false". There is one exception: if the current
513 instruction is a "ret", returns "false" without calling "jmpFct".
514 Arrangements for tracking the control flow of a "ret" must be made
515 externally. */
516 bool GenerateOopMap::jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int *data) {
517 int bci = bcs->bci();
518
519 switch (bcs->code()) {
520 case Bytecodes::_ifeq:
521 case Bytecodes::_ifne:
522 case Bytecodes::_iflt:
523 case Bytecodes::_ifge:
524 case Bytecodes::_ifgt:
525 case Bytecodes::_ifle:
526 case Bytecodes::_if_icmpeq:
527 case Bytecodes::_if_icmpne:
528 case Bytecodes::_if_icmplt:
529 case Bytecodes::_if_icmpge:
530 case Bytecodes::_if_icmpgt:
531 case Bytecodes::_if_icmple:
532 case Bytecodes::_if_acmpeq:
533 case Bytecodes::_if_acmpne:
534 case Bytecodes::_ifnull:
535 case Bytecodes::_ifnonnull:
536 (*jmpFct)(this, bcs->dest(), data);
537 (*jmpFct)(this, bci + 3, data);
538 break;
539
540 case Bytecodes::_goto:
541 (*jmpFct)(this, bcs->dest(), data);
542 break;
543 case Bytecodes::_goto_w:
544 (*jmpFct)(this, bcs->dest_w(), data);
545 break;
546 case Bytecodes::_tableswitch:
547 { Bytecode_tableswitch *tableswitch = Bytecode_tableswitch_at(bcs->bcp());
548 int len = tableswitch->length();
549
550 (*jmpFct)(this, bci + tableswitch->default_offset(), data); /* Default. jump address */
551 while (--len >= 0) {
552 (*jmpFct)(this, bci + tableswitch->dest_offset_at(len), data);
553 }
554 break;
555 }
556
557 case Bytecodes::_lookupswitch:
558 { Bytecode_lookupswitch *lookupswitch = Bytecode_lookupswitch_at(bcs->bcp());
559 int npairs = lookupswitch->number_of_pairs();
560 (*jmpFct)(this, bci + lookupswitch->default_offset(), data); /* Default. */
561 while(--npairs >= 0) {
562 LookupswitchPair *pair = lookupswitch->pair_at(npairs);
563 (*jmpFct)(this, bci + pair->offset(), data);
564 }
565 break;
566 }
567 case Bytecodes::_jsr:
568 assert(bcs->is_wide()==false, "sanity check");
569 (*jmpFct)(this, bcs->dest(), data);
570
571
572
573 break;
574 case Bytecodes::_jsr_w:
575 (*jmpFct)(this, bcs->dest_w(), data);
576 break;
577 case Bytecodes::_wide:
578 ShouldNotReachHere();
579 return true;
580 break;
581 case Bytecodes::_athrow:
582 case Bytecodes::_ireturn:
583 case Bytecodes::_lreturn:
584 case Bytecodes::_freturn:
585 case Bytecodes::_dreturn:
586 case Bytecodes::_areturn:
587 case Bytecodes::_return:
588 case Bytecodes::_ret:
589 break;
590 default:
591 return true;
592 }
593 return false;
594 }
595
596 /* Requires "pc" to be the head of a basic block; returns that basic
597 block. */
598 BasicBlock *GenerateOopMap::get_basic_block_at(int bci) const {
599 BasicBlock* bb = get_basic_block_containing(bci);
600 assert(bb->_bci == bci, "should have found BB");
601 return bb;
602 }
603
604 // Requires "pc" to be the start of an instruction; returns the basic
605 // block containing that instruction. */
606 BasicBlock *GenerateOopMap::get_basic_block_containing(int bci) const {
607 BasicBlock *bbs = _basic_blocks;
608 int lo = 0, hi = _bb_count - 1;
609
610 while (lo <= hi) {
611 int m = (lo + hi) / 2;
612 int mbci = bbs[m]._bci;
613 int nbci;
614
615 if ( m == _bb_count-1) {
616 assert( bci >= mbci && bci < method()->code_size(), "sanity check failed");
617 return bbs+m;
618 } else {
619 nbci = bbs[m+1]._bci;
620 }
621
622 if ( mbci <= bci && bci < nbci) {
623 return bbs+m;
624 } else if (mbci < bci) {
625 lo = m + 1;
626 } else {
627 assert(mbci > bci, "sanity check");
628 hi = m - 1;
629 }
630 }
631
632 fatal("should have found BB");
633 return NULL;
634 }
635
636 void GenerateOopMap::restore_state(BasicBlock *bb)
637 {
638 memcpy(_state, bb->_state, _state_len*sizeof(CellTypeState));
639 _stack_top = bb->_stack_top;
640 _monitor_top = bb->_monitor_top;
641 }
642
643 int GenerateOopMap::next_bb_start_pc(BasicBlock *bb) {
644 int bbNum = bb - _basic_blocks + 1;
645 if (bbNum == _bb_count)
646 return method()->code_size();
647
648 return _basic_blocks[bbNum]._bci;
649 }
650
651 //
652 // CellType handling methods
653 //
654
655 void GenerateOopMap::init_state() {
656 _state_len = _max_locals + _max_stack + _max_monitors;
657 _state = NEW_RESOURCE_ARRAY(CellTypeState, _state_len);
658 memset(_state, 0, _state_len * sizeof(CellTypeState));
659 _state_vec_buf = NEW_RESOURCE_ARRAY(char, MAX3(_max_locals, _max_stack, _max_monitors) + 1/*for null terminator char */);
660 }
661
662 void GenerateOopMap::make_context_uninitialized() {
663 CellTypeState* vs = vars();
664
665 for (int i = 0; i < _max_locals; i++)
666 vs[i] = CellTypeState::uninit;
667
668 _stack_top = 0;
669 _monitor_top = 0;
670 }
671
672 int GenerateOopMap::methodsig_to_effect(symbolOop signature, bool is_static, CellTypeState* effect) {
673 ComputeEntryStack ces(signature);
674 return ces.compute_for_parameters(is_static, effect);
675 }
676
677 // Return result of merging cts1 and cts2.
678 CellTypeState CellTypeState::merge(CellTypeState cts, int slot) const {
679 CellTypeState result;
680
681 assert(!is_bottom() && !cts.is_bottom(),
682 "merge of bottom values is handled elsewhere");
683
684 result._state = _state | cts._state;
685
686 // If the top bit is set, we don't need to do any more work.
687 if (!result.is_info_top()) {
688 assert((result.can_be_address() || result.can_be_reference()),
689 "only addresses and references have non-top info");
690
691 if (!equal(cts)) {
692 // The two values being merged are different. Raise to top.
693 if (result.is_reference()) {
694 result = CellTypeState::make_slot_ref(slot);
695 } else {
696 result._state |= info_conflict;
697 }
698 }
699 }
700 assert(result.is_valid_state(), "checking that CTS merge maintains legal state");
701
702 return result;
703 }
704
705 // Merge the variable state for locals and stack from cts into bbts.
706 bool GenerateOopMap::merge_local_state_vectors(CellTypeState* cts,
707 CellTypeState* bbts) {
708 int i;
709 int len = _max_locals + _stack_top;
710 bool change = false;
711
712 for (i = len - 1; i >= 0; i--) {
713 CellTypeState v = cts[i].merge(bbts[i], i);
714 change = change || !v.equal(bbts[i]);
715 bbts[i] = v;
716 }
717
718 return change;
719 }
720
721 // Merge the monitor stack state from cts into bbts.
722 bool GenerateOopMap::merge_monitor_state_vectors(CellTypeState* cts,
723 CellTypeState* bbts) {
724 bool change = false;
725 if (_max_monitors > 0 && _monitor_top != bad_monitors) {
726 // If there are no monitors in the program, or there has been
727 // a monitor matching error before this point in the program,
728 // then we do not merge in the monitor state.
729
730 int base = _max_locals + _max_stack;
731 int len = base + _monitor_top;
732 for (int i = len - 1; i >= base; i--) {
733 CellTypeState v = cts[i].merge(bbts[i], i);
734
735 // Can we prove that, when there has been a change, it will already
736 // have been detected at this point? That would make this equal
737 // check here unnecessary.
738 change = change || !v.equal(bbts[i]);
739 bbts[i] = v;
740 }
741 }
742
743 return change;
744 }
745
746 void GenerateOopMap::copy_state(CellTypeState *dst, CellTypeState *src) {
747 int len = _max_locals + _stack_top;
748 for (int i = 0; i < len; i++) {
749 if (src[i].is_nonlock_reference()) {
750 dst[i] = CellTypeState::make_slot_ref(i);
751 } else {
752 dst[i] = src[i];
753 }
754 }
755 if (_max_monitors > 0 && _monitor_top != bad_monitors) {
756 int base = _max_locals + _max_stack;
757 len = base + _monitor_top;
758 for (int i = base; i < len; i++) {
759 dst[i] = src[i];
760 }
761 }
762 }
763
764
765 // Merge the states for the current block and the next. As long as a
766 // block is reachable the locals and stack must be merged. If the
767 // stack heights don't match then this is a verification error and
768 // it's impossible to interpret the code. Simultaneously monitor
769 // states are being check to see if they nest statically. If monitor
770 // depths match up then their states are merged. Otherwise the
771 // mismatch is simply recorded and interpretation continues since
772 // monitor matching is purely informational and doesn't say anything
773 // about the correctness of the code.
774 void GenerateOopMap::merge_state_into_bb(BasicBlock *bb) {
775 assert(bb->is_alive(), "merging state into a dead basicblock");
776
777 if (_stack_top == bb->_stack_top) {
778 // always merge local state even if monitors don't match.
779 if (merge_local_state_vectors(_state, bb->_state)) {
780 bb->set_changed(true);
781 }
782 if (_monitor_top == bb->_monitor_top) {
783 // monitors still match so continue merging monitor states.
784 if (merge_monitor_state_vectors(_state, bb->_state)) {
785 bb->set_changed(true);
786 }
787 } else {
788 if (TraceMonitorMismatch) {
789 report_monitor_mismatch("monitor stack height merge conflict");
790 }
791 // When the monitor stacks are not matched, we set _monitor_top to
792 // bad_monitors. This signals that, from here on, the monitor stack cannot
793 // be trusted. In particular, monitorexit bytecodes may throw
794 // exceptions. We mark this block as changed so that the change
795 // propagates properly.
796 bb->_monitor_top = bad_monitors;
797 bb->set_changed(true);
798 _monitor_safe = false;
799 }
800 } else if (!bb->is_reachable()) {
801 // First time we look at this BB
802 copy_state(bb->_state, _state);
803 bb->_stack_top = _stack_top;
804 bb->_monitor_top = _monitor_top;
805 bb->set_changed(true);
806 } else {
807 verify_error("stack height conflict: %d vs. %d", _stack_top, bb->_stack_top);
808 }
809 }
810
811 void GenerateOopMap::merge_state(GenerateOopMap *gom, int bci, int* data) {
812 gom->merge_state_into_bb(gom->get_basic_block_at(bci));
813 }
814
815 void GenerateOopMap::set_var(int localNo, CellTypeState cts) {
816 assert(cts.is_reference() || cts.is_value() || cts.is_address(),
817 "wrong celltypestate");
818 if (localNo < 0 || localNo > _max_locals) {
819 verify_error("variable write error: r%d", localNo);
820 return;
821 }
822 vars()[localNo] = cts;
823 }
824
825 CellTypeState GenerateOopMap::get_var(int localNo) {
826 assert(localNo < _max_locals + _nof_refval_conflicts, "variable read error")
827 if (localNo < 0 || localNo > _max_locals) {
828 verify_error("variable read error: r%d", localNo);
829 return valCTS; // just to pick something;
830 }
831 return vars()[localNo];
832 }
833
834 CellTypeState GenerateOopMap::pop() {
835 if ( _stack_top <= 0) {
836 verify_error("stack underflow");
837 return valCTS; // just to pick something
838 }
839 return stack()[--_stack_top];
840 }
841
842 void GenerateOopMap::push(CellTypeState cts) {
843 if ( _stack_top >= _max_stack) {
844 verify_error("stack overflow");
845 return;
846 }
847 stack()[_stack_top++] = cts;
848 }
849
850 CellTypeState GenerateOopMap::monitor_pop() {
851 assert(_monitor_top != bad_monitors, "monitor_pop called on error monitor stack");
852 if (_monitor_top == 0) {
853 // We have detected a pop of an empty monitor stack.
854 _monitor_safe = false;
855 _monitor_top = bad_monitors;
856
857 if (TraceMonitorMismatch) {
858 report_monitor_mismatch("monitor stack underflow");
859 }
860 return CellTypeState::ref; // just to keep the analysis going.
861 }
862 return monitors()[--_monitor_top];
863 }
864
865 void GenerateOopMap::monitor_push(CellTypeState cts) {
866 assert(_monitor_top != bad_monitors, "monitor_push called on error monitor stack");
867 if (_monitor_top >= _max_monitors) {
868 // Some monitorenter is being executed more than once.
869 // This means that the monitor stack cannot be simulated.
870 _monitor_safe = false;
871 _monitor_top = bad_monitors;
872
873 if (TraceMonitorMismatch) {
874 report_monitor_mismatch("monitor stack overflow");
875 }
876 return;
877 }
878 monitors()[_monitor_top++] = cts;
879 }
880
881 //
882 // Interpretation handling methods
883 //
884
885 void GenerateOopMap::do_interpretation()
886 {
887 // "i" is just for debugging, so we can detect cases where this loop is
888 // iterated more than once.
889 int i = 0;
890 do {
891 #ifndef PRODUCT
892 if (TraceNewOopMapGeneration) {
893 tty->print("\n\nIteration #%d of do_interpretation loop, method:\n", i);
894 method()->print_name(tty);
895 tty->print("\n\n");
896 }
897 #endif
898 _conflict = false;
899 _monitor_safe = true;
900 // init_state is now called from init_basic_blocks. The length of a
901 // state vector cannot be determined until we have made a pass through
902 // the bytecodes counting the possible monitor entries.
903 if (!_got_error) init_basic_blocks();
904 if (!_got_error) setup_method_entry_state();
905 if (!_got_error) interp_all();
906 if (!_got_error) rewrite_refval_conflicts();
907 i++;
908 } while (_conflict && !_got_error);
909 }
910
911 void GenerateOopMap::init_basic_blocks() {
912 // Note: Could consider reserving only the needed space for each BB's state
913 // (entry stack may not be of maximal height for every basic block).
914 // But cumbersome since we don't know the stack heights yet. (Nor the
915 // monitor stack heights...)
916
917 _basic_blocks = NEW_RESOURCE_ARRAY(BasicBlock, _bb_count);
918
919 // Make a pass through the bytecodes. Count the number of monitorenters.
920 // This can be used an upper bound on the monitor stack depth in programs
921 // which obey stack discipline with their monitor usage. Initialize the
922 // known information about basic blocks.
923 BytecodeStream j(_method);
924 Bytecodes::Code bytecode;
925
926 int bbNo = 0;
927 int monitor_count = 0;
928 int prev_bci = -1;
929 while( (bytecode = j.next()) >= 0) {
930 if (j.code() == Bytecodes::_monitorenter) {
931 monitor_count++;
932 }
933
934 int bci = j.bci();
935 if (is_bb_header(bci)) {
936 // Initialize the basicblock structure
937 BasicBlock *bb = _basic_blocks + bbNo;
938 bb->_bci = bci;
939 bb->_max_locals = _max_locals;
940 bb->_max_stack = _max_stack;
941 bb->set_changed(false);
942 bb->_stack_top = BasicBlock::_dead_basic_block; // Initialize all basicblocks are dead.
943 bb->_monitor_top = bad_monitors;
944
945 if (bbNo > 0) {
946 _basic_blocks[bbNo - 1]._end_bci = prev_bci;
947 }
948
949 bbNo++;
950 }
951 // Remember prevous bci.
952 prev_bci = bci;
953 }
954 // Set
955 _basic_blocks[bbNo-1]._end_bci = prev_bci;
956
957
958 _max_monitors = monitor_count;
959
960 // Now that we have a bound on the depth of the monitor stack, we can
961 // initialize the CellTypeState-related information.
962 init_state();
963
964 // We allocate space for all state-vectors for all basicblocks in one huge chuck.
965 // Then in the next part of the code, we set a pointer in each _basic_block that
966 // points to each piece.
967 CellTypeState *basicBlockState = NEW_RESOURCE_ARRAY(CellTypeState, bbNo * _state_len);
968 memset(basicBlockState, 0, bbNo * _state_len * sizeof(CellTypeState));
969
970 // Make a pass over the basicblocks and assign their state vectors.
971 for (int blockNum=0; blockNum < bbNo; blockNum++) {
972 BasicBlock *bb = _basic_blocks + blockNum;
973 bb->_state = basicBlockState + blockNum * _state_len;
974
975 #ifdef ASSERT
976 if (blockNum + 1 < bbNo) {
977 address bcp = _method->bcp_from(bb->_end_bci);
978 int bc_len = Bytecodes::java_length_at(bcp);
979 assert(bb->_end_bci + bc_len == bb[1]._bci, "unmatched bci info in basicblock");
980 }
981 #endif
982 }
983 #ifdef ASSERT
984 { BasicBlock *bb = &_basic_blocks[bbNo-1];
985 address bcp = _method->bcp_from(bb->_end_bci);
986 int bc_len = Bytecodes::java_length_at(bcp);
987 assert(bb->_end_bci + bc_len == _method->code_size(), "wrong end bci");
988 }
989 #endif
990
991 // Check that the correct number of basicblocks was found
992 if (bbNo !=_bb_count) {
993 if (bbNo < _bb_count) {
994 verify_error("jump into the middle of instruction?");
995 return;
996 } else {
997 verify_error("extra basic blocks - should not happen?");
998 return;
999 }
1000 }
1001
1002 // Mark all alive blocks
1003 mark_reachable_code();
1004 }
1005
1006 void GenerateOopMap::setup_method_entry_state() {
1007
1008 // Initialize all locals to 'uninit' and set stack-height to 0
1009 make_context_uninitialized();
1010
1011 // Initialize CellState type of arguments
1012 methodsig_to_effect(method()->signature(), method()->is_static(), vars());
1013
1014 // If some references must be pre-assigned to null, then set that up
1015 initialize_vars();
1016
1017 // This is the start state
1018 merge_state_into_bb(&_basic_blocks[0]);
1019
1020 assert(_basic_blocks[0].changed(), "we are not getting off the ground");
1021 }
1022
1023 // The instruction at bci is changing size by "delta". Update the basic blocks.
1024 void GenerateOopMap::update_basic_blocks(int bci, int delta,
1025 int new_method_size) {
1026 assert(new_method_size >= method()->code_size() + delta,
1027 "new method size is too small");
1028 int newWords = binsToHold(new_method_size);
1029
1030 uintptr_t * new_bb_hdr_bits = NEW_RESOURCE_ARRAY(uintptr_t, newWords);
1031
1032 BitMap bb_bits(new_bb_hdr_bits, new_method_size);
1033 bb_bits.clear();
1034
1035 for(int k = 0; k < _bb_count; k++) {
1036 if (_basic_blocks[k]._bci > bci) {
1037 _basic_blocks[k]._bci += delta;
1038 _basic_blocks[k]._end_bci += delta;
1039 }
1040 bb_bits.at_put(_basic_blocks[k]._bci, true);
1041 }
1042 _bb_hdr_bits = new_bb_hdr_bits ;
1043 }
1044
1045 //
1046 // Initvars handling
1047 //
1048
1049 void GenerateOopMap::initialize_vars() {
1050 for (int k = 0; k < _init_vars->length(); k++)
1051 _state[_init_vars->at(k)] = CellTypeState::make_slot_ref(k);
1052 }
1053
1054 void GenerateOopMap::add_to_ref_init_set(int localNo) {
1055
1056 if (TraceNewOopMapGeneration)
1057 tty->print_cr("Added init vars: %d", localNo);
1058
1059 // Is it already in the set?
1060 if (_init_vars->contains(localNo) )
1061 return;
1062
1063 _init_vars->append(localNo);
1064 }
1065
1066 //
1067 // Interpreration code
1068 //
1069
1070 void GenerateOopMap::interp_all() {
1071 bool change = true;
1072
1073 while (change && !_got_error) {
1074 change = false;
1075 for (int i = 0; i < _bb_count && !_got_error; i++) {
1076 BasicBlock *bb = &_basic_blocks[i];
1077 if (bb->changed()) {
1078 if (_got_error) return;
1079 change = true;
1080 bb->set_changed(false);
1081 interp_bb(bb);
1082 }
1083 }
1084 }
1085 }
1086
1087 void GenerateOopMap::interp_bb(BasicBlock *bb) {
1088
1089 // We do not want to do anything in case the basic-block has not been initialized. This
1090 // will happen in the case where there is dead-code hang around in a method.
1091 assert(bb->is_reachable(), "should be reachable or deadcode exist");
1092 restore_state(bb);
1093
1094 BytecodeStream itr(_method);
1095
1096 // Set iterator interval to be the current basicblock
1097 int lim_bci = next_bb_start_pc(bb);
1098 itr.set_interval(bb->_bci, lim_bci);
1099 assert(lim_bci != bb->_bci, "must be at least one instruction in a basicblock");
1100 itr.next(); // read first instruction
1101
1102 // Iterates through all bytecodes except the last in a basic block.
1103 // We handle the last one special, since there is controlflow change.
1104 while(itr.next_bci() < lim_bci && !_got_error) {
1105 if (_has_exceptions || _monitor_top != 0) {
1106 // We do not need to interpret the results of exceptional
1107 // continuation from this instruction when the method has no
1108 // exception handlers and the monitor stack is currently
1109 // empty.
1110 do_exception_edge(&itr);
1111 }
1112 interp1(&itr);
1113 itr.next();
1114 }
1115
1116 // Handle last instruction.
1117 if (!_got_error) {
1118 assert(itr.next_bci() == lim_bci, "must point to end");
1119 if (_has_exceptions || _monitor_top != 0) {
1120 do_exception_edge(&itr);
1121 }
1122 interp1(&itr);
1123
1124 bool fall_through = jump_targets_do(&itr, GenerateOopMap::merge_state, NULL);
1125 if (_got_error) return;
1126
1127 if (itr.code() == Bytecodes::_ret) {
1128 assert(!fall_through, "cannot be set if ret instruction");
1129 // Automatically handles 'wide' ret indicies
1130 ret_jump_targets_do(&itr, GenerateOopMap::merge_state, itr.get_index(), NULL);
1131 } else if (fall_through) {
1132 // Hit end of BB, but the instr. was a fall-through instruction,
1133 // so perform transition as if the BB ended in a "jump".
1134 if (lim_bci != bb[1]._bci) {
1135 verify_error("bytecodes fell through last instruction");
1136 return;
1137 }
1138 merge_state_into_bb(bb + 1);
1139 }
1140 }
1141 }
1142
1143 void GenerateOopMap::do_exception_edge(BytecodeStream* itr) {
1144 // Only check exception edge, if bytecode can trap
1145 if (!Bytecodes::can_trap(itr->code())) return;
1146 switch (itr->code()) {
1147 case Bytecodes::_aload_0:
1148 // These bytecodes can trap for rewriting. We need to assume that
1149 // they do not throw exceptions to make the monitor analysis work.
1150 return;
1151
1152 case Bytecodes::_ireturn:
1153 case Bytecodes::_lreturn:
1154 case Bytecodes::_freturn:
1155 case Bytecodes::_dreturn:
1156 case Bytecodes::_areturn:
1157 case Bytecodes::_return:
1158 // If the monitor stack height is not zero when we leave the method,
1159 // then we are either exiting with a non-empty stack or we have
1160 // found monitor trouble earlier in our analysis. In either case,
1161 // assume an exception could be taken here.
1162 if (_monitor_top == 0) {
1163 return;
1164 }
1165 break;
1166
1167 case Bytecodes::_monitorexit:
1168 // If the monitor stack height is bad_monitors, then we have detected a
1169 // monitor matching problem earlier in the analysis. If the
1170 // monitor stack height is 0, we are about to pop a monitor
1171 // off of an empty stack. In either case, the bytecode
1172 // could throw an exception.
1173 if (_monitor_top != bad_monitors && _monitor_top != 0) {
1174 return;
1175 }
1176 break;
1177 }
1178
1179 if (_has_exceptions) {
1180 int bci = itr->bci();
1181 typeArrayOop exct = method()->exception_table();
1182 for(int i = 0; i< exct->length(); i+=4) {
1183 int start_pc = exct->int_at(i);
1184 int end_pc = exct->int_at(i+1);
1185 int handler_pc = exct->int_at(i+2);
1186 int catch_type = exct->int_at(i+3);
1187
1188 if (start_pc <= bci && bci < end_pc) {
1189 BasicBlock *excBB = get_basic_block_at(handler_pc);
1190 CellTypeState *excStk = excBB->stack();
1191 CellTypeState *cOpStck = stack();
1192 CellTypeState cOpStck_0 = cOpStck[0];
1193 int cOpStackTop = _stack_top;
1194
1195 // Exception stacks are always the same.
1196 assert(method()->max_stack() > 0, "sanity check");
1197
1198 // We remembered the size and first element of "cOpStck"
1199 // above; now we temporarily set them to the appropriate
1200 // values for an exception handler. */
1201 cOpStck[0] = CellTypeState::make_slot_ref(_max_locals);
1202 _stack_top = 1;
1203
1204 merge_state_into_bb(excBB);
1205
1206 // Now undo the temporary change.
1207 cOpStck[0] = cOpStck_0;
1208 _stack_top = cOpStackTop;
1209
1210 // If this is a "catch all" handler, then we do not need to
1211 // consider any additional handlers.
1212 if (catch_type == 0) {
1213 return;
1214 }
1215 }
1216 }
1217 }
1218
1219 // It is possible that none of the exception handlers would have caught
1220 // the exception. In this case, we will exit the method. We must
1221 // ensure that the monitor stack is empty in this case.
1222 if (_monitor_top == 0) {
1223 return;
1224 }
1225
1226 // We pessimistically assume that this exception can escape the
1227 // method. (It is possible that it will always be caught, but
1228 // we don't care to analyse the types of the catch clauses.)
1229
1230 // We don't set _monitor_top to bad_monitors because there are no successors
1231 // to this exceptional exit.
1232
1233 if (TraceMonitorMismatch && _monitor_safe) {
1234 // We check _monitor_safe so that we only report the first mismatched
1235 // exceptional exit.
1236 report_monitor_mismatch("non-empty monitor stack at exceptional exit");
1237 }
1238 _monitor_safe = false;
1239
1240 }
1241
1242 void GenerateOopMap::report_monitor_mismatch(const char *msg) {
1243 #ifndef PRODUCT
1244 tty->print(" Monitor mismatch in method ");
1245 method()->print_short_name(tty);
1246 tty->print_cr(": %s", msg);
1247 #endif
1248 }
1249
1250 void GenerateOopMap::print_states(outputStream *os,
1251 CellTypeState* vec, int num) {
1252 for (int i = 0; i < num; i++) {
1253 vec[i].print(tty);
1254 }
1255 }
1256
1257 // Print the state values at the current bytecode.
1258 void GenerateOopMap::print_current_state(outputStream *os,
1259 BytecodeStream *currentBC,
1260 bool detailed) {
1261
1262 if (detailed) {
1263 os->print(" %4d vars = ", currentBC->bci());
1264 print_states(os, vars(), _max_locals);
1265 os->print(" %s", Bytecodes::name(currentBC->code()));
1266 switch(currentBC->code()) {
1267 case Bytecodes::_invokevirtual:
1268 case Bytecodes::_invokespecial:
1269 case Bytecodes::_invokestatic:
1270 case Bytecodes::_invokeinterface:
1271 int idx = currentBC->get_index_big();
1272 constantPoolOop cp = method()->constants();
1273 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
1274 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1275 symbolOop signature = cp->symbol_at(signatureIdx);
1276 os->print("%s", signature->as_C_string());
1277 }
1278 os->cr();
1279 os->print(" stack = ");
1280 print_states(os, stack(), _stack_top);
1281 os->cr();
1282 if (_monitor_top != bad_monitors) {
1283 os->print(" monitors = ");
1284 print_states(os, monitors(), _monitor_top);
1285 } else {
1286 os->print(" [bad monitor stack]");
1287 }
1288 os->cr();
1289 } else {
1290 os->print(" %4d vars = '%s' ", currentBC->bci(), state_vec_to_string(vars(), _max_locals));
1291 os->print(" stack = '%s' ", state_vec_to_string(stack(), _stack_top));
1292 if (_monitor_top != bad_monitors) {
1293 os->print(" monitors = '%s' \t%s", state_vec_to_string(monitors(), _monitor_top), Bytecodes::name(currentBC->code()));
1294 } else {
1295 os->print(" [bad monitor stack]");
1296 }
1297 switch(currentBC->code()) {
1298 case Bytecodes::_invokevirtual:
1299 case Bytecodes::_invokespecial:
1300 case Bytecodes::_invokestatic:
1301 case Bytecodes::_invokeinterface:
1302 int idx = currentBC->get_index_big();
1303 constantPoolOop cp = method()->constants();
1304 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
1305 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1306 symbolOop signature = cp->symbol_at(signatureIdx);
1307 os->print("%s", signature->as_C_string());
1308 }
1309 os->cr();
1310 }
1311 }
1312
1313 // Sets the current state to be the state after executing the
1314 // current instruction, starting in the current state.
1315 void GenerateOopMap::interp1(BytecodeStream *itr) {
1316 if (TraceNewOopMapGeneration) {
1317 print_current_state(tty, itr, TraceNewOopMapGenerationDetailed);
1318 }
1319
1320 // Should we report the results? Result is reported *before* the instruction at the current bci is executed.
1321 // However, not for calls. For calls we do not want to include the arguments, so we postpone the reporting until
1322 // they have been popped (in method ppl).
1323 if (_report_result == true) {
1324 switch(itr->code()) {
1325 case Bytecodes::_invokevirtual:
1326 case Bytecodes::_invokespecial:
1327 case Bytecodes::_invokestatic:
1328 case Bytecodes::_invokeinterface:
1329 _itr_send = itr;
1330 _report_result_for_send = true;
1331 break;
1332 default:
1333 fill_stackmap_for_opcodes(itr, vars(), stack(), _stack_top);
1334 break;
1335 }
1336 }
1337
1338 // abstract interpretation of current opcode
1339 switch(itr->code()) {
1340 case Bytecodes::_nop: break;
1341 case Bytecodes::_goto: break;
1342 case Bytecodes::_goto_w: break;
1343 case Bytecodes::_iinc: break;
1344 case Bytecodes::_return: do_return_monitor_check();
1345 break;
1346
1347 case Bytecodes::_aconst_null:
1348 case Bytecodes::_new: ppush1(CellTypeState::make_line_ref(itr->bci()));
1349 break;
1350
1351 case Bytecodes::_iconst_m1:
1352 case Bytecodes::_iconst_0:
1353 case Bytecodes::_iconst_1:
1354 case Bytecodes::_iconst_2:
1355 case Bytecodes::_iconst_3:
1356 case Bytecodes::_iconst_4:
1357 case Bytecodes::_iconst_5:
1358 case Bytecodes::_fconst_0:
1359 case Bytecodes::_fconst_1:
1360 case Bytecodes::_fconst_2:
1361 case Bytecodes::_bipush:
1362 case Bytecodes::_sipush: ppush1(valCTS); break;
1363
1364 case Bytecodes::_lconst_0:
1365 case Bytecodes::_lconst_1:
1366 case Bytecodes::_dconst_0:
1367 case Bytecodes::_dconst_1: ppush(vvCTS); break;
1368
1369 case Bytecodes::_ldc2_w: ppush(vvCTS); break;
1370
1371 case Bytecodes::_ldc: do_ldc(itr->get_index(), itr->bci()); break;
1372 case Bytecodes::_ldc_w: do_ldc(itr->get_index_big(), itr->bci());break;
1373
1374 case Bytecodes::_iload:
1375 case Bytecodes::_fload: ppload(vCTS, itr->get_index()); break;
1376
1377 case Bytecodes::_lload:
1378 case Bytecodes::_dload: ppload(vvCTS,itr->get_index()); break;
1379
1380 case Bytecodes::_aload: ppload(rCTS, itr->get_index()); break;
1381
1382 case Bytecodes::_iload_0:
1383 case Bytecodes::_fload_0: ppload(vCTS, 0); break;
1384 case Bytecodes::_iload_1:
1385 case Bytecodes::_fload_1: ppload(vCTS, 1); break;
1386 case Bytecodes::_iload_2:
1387 case Bytecodes::_fload_2: ppload(vCTS, 2); break;
1388 case Bytecodes::_iload_3:
1389 case Bytecodes::_fload_3: ppload(vCTS, 3); break;
1390
1391 case Bytecodes::_lload_0:
1392 case Bytecodes::_dload_0: ppload(vvCTS, 0); break;
1393 case Bytecodes::_lload_1:
1394 case Bytecodes::_dload_1: ppload(vvCTS, 1); break;
1395 case Bytecodes::_lload_2:
1396 case Bytecodes::_dload_2: ppload(vvCTS, 2); break;
1397 case Bytecodes::_lload_3:
1398 case Bytecodes::_dload_3: ppload(vvCTS, 3); break;
1399
1400 case Bytecodes::_aload_0: ppload(rCTS, 0); break;
1401 case Bytecodes::_aload_1: ppload(rCTS, 1); break;
1402 case Bytecodes::_aload_2: ppload(rCTS, 2); break;
1403 case Bytecodes::_aload_3: ppload(rCTS, 3); break;
1404
1405 case Bytecodes::_iaload:
1406 case Bytecodes::_faload:
1407 case Bytecodes::_baload:
1408 case Bytecodes::_caload:
1409 case Bytecodes::_saload: pp(vrCTS, vCTS); break;
1410
1411 case Bytecodes::_laload: pp(vrCTS, vvCTS); break;
1412 case Bytecodes::_daload: pp(vrCTS, vvCTS); break;
1413
1414 case Bytecodes::_aaload: pp_new_ref(vrCTS, itr->bci()); break;
1415
1416 case Bytecodes::_istore:
1417 case Bytecodes::_fstore: ppstore(vCTS, itr->get_index()); break;
1418
1419 case Bytecodes::_lstore:
1420 case Bytecodes::_dstore: ppstore(vvCTS, itr->get_index()); break;
1421
1422 case Bytecodes::_astore: do_astore(itr->get_index()); break;
1423
1424 case Bytecodes::_istore_0:
1425 case Bytecodes::_fstore_0: ppstore(vCTS, 0); break;
1426 case Bytecodes::_istore_1:
1427 case Bytecodes::_fstore_1: ppstore(vCTS, 1); break;
1428 case Bytecodes::_istore_2:
1429 case Bytecodes::_fstore_2: ppstore(vCTS, 2); break;
1430 case Bytecodes::_istore_3:
1431 case Bytecodes::_fstore_3: ppstore(vCTS, 3); break;
1432
1433 case Bytecodes::_lstore_0:
1434 case Bytecodes::_dstore_0: ppstore(vvCTS, 0); break;
1435 case Bytecodes::_lstore_1:
1436 case Bytecodes::_dstore_1: ppstore(vvCTS, 1); break;
1437 case Bytecodes::_lstore_2:
1438 case Bytecodes::_dstore_2: ppstore(vvCTS, 2); break;
1439 case Bytecodes::_lstore_3:
1440 case Bytecodes::_dstore_3: ppstore(vvCTS, 3); break;
1441
1442 case Bytecodes::_astore_0: do_astore(0); break;
1443 case Bytecodes::_astore_1: do_astore(1); break;
1444 case Bytecodes::_astore_2: do_astore(2); break;
1445 case Bytecodes::_astore_3: do_astore(3); break;
1446
1447 case Bytecodes::_iastore:
1448 case Bytecodes::_fastore:
1449 case Bytecodes::_bastore:
1450 case Bytecodes::_castore:
1451 case Bytecodes::_sastore: ppop(vvrCTS); break;
1452 case Bytecodes::_lastore:
1453 case Bytecodes::_dastore: ppop(vvvrCTS); break;
1454 case Bytecodes::_aastore: ppop(rvrCTS); break;
1455
1456 case Bytecodes::_pop: ppop_any(1); break;
1457 case Bytecodes::_pop2: ppop_any(2); break;
1458
1459 case Bytecodes::_dup: ppdupswap(1, "11"); break;
1460 case Bytecodes::_dup_x1: ppdupswap(2, "121"); break;
1461 case Bytecodes::_dup_x2: ppdupswap(3, "1321"); break;
1462 case Bytecodes::_dup2: ppdupswap(2, "2121"); break;
1463 case Bytecodes::_dup2_x1: ppdupswap(3, "21321"); break;
1464 case Bytecodes::_dup2_x2: ppdupswap(4, "214321"); break;
1465 case Bytecodes::_swap: ppdupswap(2, "12"); break;
1466
1467 case Bytecodes::_iadd:
1468 case Bytecodes::_fadd:
1469 case Bytecodes::_isub:
1470 case Bytecodes::_fsub:
1471 case Bytecodes::_imul:
1472 case Bytecodes::_fmul:
1473 case Bytecodes::_idiv:
1474 case Bytecodes::_fdiv:
1475 case Bytecodes::_irem:
1476 case Bytecodes::_frem:
1477 case Bytecodes::_ishl:
1478 case Bytecodes::_ishr:
1479 case Bytecodes::_iushr:
1480 case Bytecodes::_iand:
1481 case Bytecodes::_ior:
1482 case Bytecodes::_ixor:
1483 case Bytecodes::_l2f:
1484 case Bytecodes::_l2i:
1485 case Bytecodes::_d2f:
1486 case Bytecodes::_d2i:
1487 case Bytecodes::_fcmpl:
1488 case Bytecodes::_fcmpg: pp(vvCTS, vCTS); break;
1489
1490 case Bytecodes::_ladd:
1491 case Bytecodes::_dadd:
1492 case Bytecodes::_lsub:
1493 case Bytecodes::_dsub:
1494 case Bytecodes::_lmul:
1495 case Bytecodes::_dmul:
1496 case Bytecodes::_ldiv:
1497 case Bytecodes::_ddiv:
1498 case Bytecodes::_lrem:
1499 case Bytecodes::_drem:
1500 case Bytecodes::_land:
1501 case Bytecodes::_lor:
1502 case Bytecodes::_lxor: pp(vvvvCTS, vvCTS); break;
1503
1504 case Bytecodes::_ineg:
1505 case Bytecodes::_fneg:
1506 case Bytecodes::_i2f:
1507 case Bytecodes::_f2i:
1508 case Bytecodes::_i2c:
1509 case Bytecodes::_i2s:
1510 case Bytecodes::_i2b: pp(vCTS, vCTS); break;
1511
1512 case Bytecodes::_lneg:
1513 case Bytecodes::_dneg:
1514 case Bytecodes::_l2d:
1515 case Bytecodes::_d2l: pp(vvCTS, vvCTS); break;
1516
1517 case Bytecodes::_lshl:
1518 case Bytecodes::_lshr:
1519 case Bytecodes::_lushr: pp(vvvCTS, vvCTS); break;
1520
1521 case Bytecodes::_i2l:
1522 case Bytecodes::_i2d:
1523 case Bytecodes::_f2l:
1524 case Bytecodes::_f2d: pp(vCTS, vvCTS); break;
1525
1526 case Bytecodes::_lcmp: pp(vvvvCTS, vCTS); break;
1527 case Bytecodes::_dcmpl:
1528 case Bytecodes::_dcmpg: pp(vvvvCTS, vCTS); break;
1529
1530 case Bytecodes::_ifeq:
1531 case Bytecodes::_ifne:
1532 case Bytecodes::_iflt:
1533 case Bytecodes::_ifge:
1534 case Bytecodes::_ifgt:
1535 case Bytecodes::_ifle:
1536 case Bytecodes::_tableswitch: ppop1(valCTS);
1537 break;
1538 case Bytecodes::_ireturn:
1539 case Bytecodes::_freturn: do_return_monitor_check();
1540 ppop1(valCTS);
1541 break;
1542 case Bytecodes::_if_icmpeq:
1543 case Bytecodes::_if_icmpne:
1544 case Bytecodes::_if_icmplt:
1545 case Bytecodes::_if_icmpge:
1546 case Bytecodes::_if_icmpgt:
1547 case Bytecodes::_if_icmple: ppop(vvCTS);
1548 break;
1549
1550 case Bytecodes::_lreturn: do_return_monitor_check();
1551 ppop(vvCTS);
1552 break;
1553
1554 case Bytecodes::_dreturn: do_return_monitor_check();
1555 ppop(vvCTS);
1556 break;
1557
1558 case Bytecodes::_if_acmpeq:
1559 case Bytecodes::_if_acmpne: ppop(rrCTS); break;
1560
1561 case Bytecodes::_jsr: do_jsr(itr->dest()); break;
1562 case Bytecodes::_jsr_w: do_jsr(itr->dest_w()); break;
1563
1564 case Bytecodes::_getstatic: do_field(true, true,
1565 itr->get_index_big(),
1566 itr->bci()); break;
1567 case Bytecodes::_putstatic: do_field(false, true, itr->get_index_big(), itr->bci()); break;
1568 case Bytecodes::_getfield: do_field(true, false, itr->get_index_big(), itr->bci()); break;
1569 case Bytecodes::_putfield: do_field(false, false, itr->get_index_big(), itr->bci()); break;
1570
1571 case Bytecodes::_invokevirtual:
1572 case Bytecodes::_invokespecial: do_method(false, false, itr->get_index_big(), itr->bci()); break;
1573 case Bytecodes::_invokestatic: do_method(true, false, itr->get_index_big(), itr->bci()); break;
1574 case Bytecodes::_invokeinterface: do_method(false, true, itr->get_index_big(), itr->bci()); break;
1575 case Bytecodes::_newarray:
1576 case Bytecodes::_anewarray: pp_new_ref(vCTS, itr->bci()); break;
1577 case Bytecodes::_checkcast: do_checkcast(); break;
1578 case Bytecodes::_arraylength:
1579 case Bytecodes::_instanceof: pp(rCTS, vCTS); break;
1580 case Bytecodes::_monitorenter: do_monitorenter(itr->bci()); break;
1581 case Bytecodes::_monitorexit: do_monitorexit(itr->bci()); break;
1582
1583 case Bytecodes::_athrow: // handled by do_exception_edge() BUT ...
1584 // vlh(apple): do_exception_edge() does not get
1585 // called if method has no exception handlers
1586 if ((!_has_exceptions) && (_monitor_top > 0)) {
1587 _monitor_safe = false;
1588 }
1589 break;
1590
1591 case Bytecodes::_areturn: do_return_monitor_check();
1592 ppop1(refCTS);
1593 break;
1594 case Bytecodes::_ifnull:
1595 case Bytecodes::_ifnonnull: ppop1(refCTS); break;
1596 case Bytecodes::_multianewarray: do_multianewarray(*(itr->bcp()+3), itr->bci()); break;
1597
1598 case Bytecodes::_wide: fatal("Iterator should skip this bytecode"); break;
1599 case Bytecodes::_ret: break;
1600
1601 // Java opcodes
1602 case Bytecodes::_lookupswitch: ppop1(valCTS); break;
1603
1604 default:
1605 tty->print("unexpected opcode: %d\n", itr->code());
1606 ShouldNotReachHere();
1607 break;
1608 }
1609 }
1610
1611 void GenerateOopMap::check_type(CellTypeState expected, CellTypeState actual) {
1612 if (!expected.equal_kind(actual)) {
1613 verify_error("wrong type on stack (found: %c expected: %c)", actual.to_char(), expected.to_char());
1614 }
1615 }
1616
1617 void GenerateOopMap::ppstore(CellTypeState *in, int loc_no) {
1618 while(!(*in).is_bottom()) {
1619 CellTypeState expected =*in++;
1620 CellTypeState actual = pop();
1621 check_type(expected, actual);
1622 assert(loc_no >= 0, "sanity check");
1623 set_var(loc_no++, actual);
1624 }
1625 }
1626
1627 void GenerateOopMap::ppload(CellTypeState *out, int loc_no) {
1628 while(!(*out).is_bottom()) {
1629 CellTypeState out1 = *out++;
1630 CellTypeState vcts = get_var(loc_no);
1631 assert(out1.can_be_reference() || out1.can_be_value(),
1632 "can only load refs. and values.");
1633 if (out1.is_reference()) {
1634 assert(loc_no>=0, "sanity check");
1635 if (!vcts.is_reference()) {
1636 // We were asked to push a reference, but the type of the
1637 // variable can be something else
1638 _conflict = true;
1639 if (vcts.can_be_uninit()) {
1640 // It is a ref-uninit conflict (at least). If there are other
1641 // problems, we'll get them in the next round
1642 add_to_ref_init_set(loc_no);
1643 vcts = out1;
1644 } else {
1645 // It wasn't a ref-uninit conflict. So must be a
1646 // ref-val or ref-pc conflict. Split the variable.
1647 record_refval_conflict(loc_no);
1648 vcts = out1;
1649 }
1650 push(out1); // recover...
1651 } else {
1652 push(vcts); // preserve reference.
1653 }
1654 // Otherwise it is a conflict, but one that verification would
1655 // have caught if illegal. In particular, it can't be a topCTS
1656 // resulting from mergeing two difference pcCTS's since the verifier
1657 // would have rejected any use of such a merge.
1658 } else {
1659 push(out1); // handle val/init conflict
1660 }
1661 loc_no++;
1662 }
1663 }
1664
1665 void GenerateOopMap::ppdupswap(int poplen, const char *out) {
1666 CellTypeState actual[5];
1667 assert(poplen < 5, "this must be less than length of actual vector");
1668
1669 // pop all arguments
1670 for(int i = 0; i < poplen; i++) actual[i] = pop();
1671
1672 // put them back
1673 char push_ch = *out++;
1674 while (push_ch != '\0') {
1675 int idx = push_ch - '1';
1676 assert(idx >= 0 && idx < poplen, "wrong arguments");
1677 push(actual[idx]);
1678 push_ch = *out++;
1679 }
1680 }
1681
1682 void GenerateOopMap::ppop1(CellTypeState out) {
1683 CellTypeState actual = pop();
1684 check_type(out, actual);
1685 }
1686
1687 void GenerateOopMap::ppop(CellTypeState *out) {
1688 while (!(*out).is_bottom()) {
1689 ppop1(*out++);
1690 }
1691 }
1692
1693 void GenerateOopMap::ppush1(CellTypeState in) {
1694 assert(in.is_reference() | in.is_value(), "sanity check");
1695 push(in);
1696 }
1697
1698 void GenerateOopMap::ppush(CellTypeState *in) {
1699 while (!(*in).is_bottom()) {
1700 ppush1(*in++);
1701 }
1702 }
1703
1704 void GenerateOopMap::pp(CellTypeState *in, CellTypeState *out) {
1705 ppop(in);
1706 ppush(out);
1707 }
1708
1709 void GenerateOopMap::pp_new_ref(CellTypeState *in, int bci) {
1710 ppop(in);
1711 ppush1(CellTypeState::make_line_ref(bci));
1712 }
1713
1714 void GenerateOopMap::ppop_any(int poplen) {
1715 if (_stack_top >= poplen) {
1716 _stack_top -= poplen;
1717 } else {
1718 verify_error("stack underflow");
1719 }
1720 }
1721
1722 // Replace all occurences of the state 'match' with the state 'replace'
1723 // in our current state vector.
1724 void GenerateOopMap::replace_all_CTS_matches(CellTypeState match,
1725 CellTypeState replace) {
1726 int i;
1727 int len = _max_locals + _stack_top;
1728 bool change = false;
1729
1730 for (i = len - 1; i >= 0; i--) {
1731 if (match.equal(_state[i])) {
1732 _state[i] = replace;
1733 }
1734 }
1735
1736 if (_monitor_top > 0) {
1737 int base = _max_locals + _max_stack;
1738 len = base + _monitor_top;
1739 for (i = len - 1; i >= base; i--) {
1740 if (match.equal(_state[i])) {
1741 _state[i] = replace;
1742 }
1743 }
1744 }
1745 }
1746
1747 void GenerateOopMap::do_checkcast() {
1748 CellTypeState actual = pop();
1749 check_type(refCTS, actual);
1750 push(actual);
1751 }
1752
1753 void GenerateOopMap::do_monitorenter(int bci) {
1754 CellTypeState actual = pop();
1755 if (_monitor_top == bad_monitors) {
1756 return;
1757 }
1758
1759 // Bail out when we get repeated locks on an identical monitor. This case
1760 // isn't too hard to handle and can be made to work if supporting nested
1761 // redundant synchronized statements becomes a priority.
1762 //
1763 // See also "Note" in do_monitorexit(), below.
1764 if (actual.is_lock_reference()) {
1765 _monitor_top = bad_monitors;
1766 _monitor_safe = false;
1767
1768 if (TraceMonitorMismatch) {
1769 report_monitor_mismatch("nested redundant lock -- bailout...");
1770 }
1771 return;
1772 }
1773
1774 CellTypeState lock = CellTypeState::make_lock_ref(bci);
1775 check_type(refCTS, actual);
1776 if (!actual.is_info_top()) {
1777 replace_all_CTS_matches(actual, lock);
1778 monitor_push(lock);
1779 }
1780 }
1781
1782 void GenerateOopMap::do_monitorexit(int bci) {
1783 CellTypeState actual = pop();
1784 if (_monitor_top == bad_monitors) {
1785 return;
1786 }
1787 check_type(refCTS, actual);
1788 CellTypeState expected = monitor_pop();
1789 if (!actual.is_lock_reference() || !expected.equal(actual)) {
1790 // The monitor we are exiting is not verifiably the one
1791 // on the top of our monitor stack. This causes a monitor
1792 // mismatch.
1793 _monitor_top = bad_monitors;
1794 _monitor_safe = false;
1795
1796 // We need to mark this basic block as changed so that
1797 // this monitorexit will be visited again. We need to
1798 // do this to ensure that we have accounted for the
1799 // possibility that this bytecode will throw an
1800 // exception.
1801 BasicBlock* bb = get_basic_block_containing(bci);
1802 bb->set_changed(true);
1803 bb->_monitor_top = bad_monitors;
1804
1805 if (TraceMonitorMismatch) {
1806 report_monitor_mismatch("improper monitor pair");
1807 }
1808 } else {
1809 // This code is a fix for the case where we have repeated
1810 // locking of the same object in straightline code. We clear
1811 // out the lock when it is popped from the monitor stack
1812 // and replace it with an unobtrusive reference value that can
1813 // be locked again.
1814 //
1815 // Note: when generateOopMap is fixed to properly handle repeated,
1816 // nested, redundant locks on the same object, then this
1817 // fix will need to be removed at that time.
1818 replace_all_CTS_matches(actual, CellTypeState::make_line_ref(bci));
1819 }
1820 }
1821
1822 void GenerateOopMap::do_return_monitor_check() {
1823 if (_monitor_top > 0) {
1824 // The monitor stack must be empty when we leave the method
1825 // for the monitors to be properly matched.
1826 _monitor_safe = false;
1827
1828 // Since there are no successors to the *return bytecode, it
1829 // isn't necessary to set _monitor_top to bad_monitors.
1830
1831 if (TraceMonitorMismatch) {
1832 report_monitor_mismatch("non-empty monitor stack at return");
1833 }
1834 }
1835 }
1836
1837 void GenerateOopMap::do_jsr(int targ_bci) {
1838 push(CellTypeState::make_addr(targ_bci));
1839 }
1840
1841
1842
1843 void GenerateOopMap::do_ldc(int idx, int bci) {
1844 constantPoolOop cp = method()->constants();
1845 constantTag tag = cp->tag_at(idx);
1846
1847 CellTypeState cts = (tag.is_string() || tag.is_unresolved_string() ||
1848 tag.is_klass() || tag.is_unresolved_klass())
1849 ? CellTypeState::make_line_ref(bci) : valCTS;
1850 ppush1(cts);
1851 }
1852
1853 void GenerateOopMap::do_multianewarray(int dims, int bci) {
1854 assert(dims >= 1, "sanity check");
1855 for(int i = dims -1; i >=0; i--) {
1856 ppop1(valCTS);
1857 }
1858 ppush1(CellTypeState::make_line_ref(bci));
1859 }
1860
1861 void GenerateOopMap::do_astore(int idx) {
1862 CellTypeState r_or_p = pop();
1863 if (!r_or_p.is_address() && !r_or_p.is_reference()) {
1864 // We actually expected ref or pc, but we only report that we expected a ref. It does not
1865 // really matter (at least for now)
1866 verify_error("wrong type on stack (found: %c, expected: {pr})", r_or_p.to_char());
1867 return;
1868 }
1869 set_var(idx, r_or_p);
1870 }
1871
1872 // Copies bottom/zero terminated CTS string from "src" into "dst".
1873 // Does NOT terminate with a bottom. Returns the number of cells copied.
1874 int GenerateOopMap::copy_cts(CellTypeState *dst, CellTypeState *src) {
1875 int idx = 0;
1876 while (!src[idx].is_bottom()) {
1877 dst[idx] = src[idx];
1878 idx++;
1879 }
1880 return idx;
1881 }
1882
1883 void GenerateOopMap::do_field(int is_get, int is_static, int idx, int bci) {
1884 // Dig up signature for field in constant pool
1885 constantPoolOop cp = method()->constants();
1886 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
1887 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1888 symbolOop signature = cp->symbol_at(signatureIdx);
1889
1890 // Parse signature (espcially simple for fields)
1891 assert(signature->utf8_length() > 0, "field signatures cannot have zero length");
1892 // The signature is UFT8 encoded, but the first char is always ASCII for signatures.
1893 char sigch = (char)*(signature->base());
1894 CellTypeState temp[4];
1895 CellTypeState *eff = sigchar_to_effect(sigch, bci, temp);
1896
1897 CellTypeState in[4];
1898 CellTypeState *out;
1899 int i = 0;
1900
1901 if (is_get) {
1902 out = eff;
1903 } else {
1904 out = epsilonCTS;
1905 i = copy_cts(in, eff);
1906 }
1907 if (!is_static) in[i++] = CellTypeState::ref;
1908 in[i] = CellTypeState::bottom;
1909 assert(i<=3, "sanity check");
1910 pp(in, out);
1911 }
1912
1913 void GenerateOopMap::do_method(int is_static, int is_interface, int idx, int bci) {
1914 // Dig up signature for field in constant pool
1915 constantPoolOop cp = _method->constants();
1916 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
1917 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1918 symbolOop signature = cp->symbol_at(signatureIdx);
1919
1920 // Parse method signature
1921 CellTypeState out[4];
1922 CellTypeState in[MAXARGSIZE+1]; // Includes result
1923 ComputeCallStack cse(signature);
1924
1925 // Compute return type
1926 int res_length= cse.compute_for_returntype(out);
1927
1928 // Temporary hack.
1929 if (out[0].equal(CellTypeState::ref) && out[1].equal(CellTypeState::bottom)) {
1930 out[0] = CellTypeState::make_line_ref(bci);
1931 }
1932
1933 assert(res_length<=4, "max value should be vv");
1934
1935 // Compute arguments
1936 int arg_length = cse.compute_for_parameters(is_static != 0, in);
1937 assert(arg_length<=MAXARGSIZE, "too many locals");
1938
1939 // Pop arguments
1940 for (int i = arg_length - 1; i >= 0; i--) ppop1(in[i]);// Do args in reverse order.
1941
1942 // Report results
1943 if (_report_result_for_send == true) {
1944 fill_stackmap_for_opcodes(_itr_send, vars(), stack(), _stack_top);
1945 _report_result_for_send = false;
1946 }
1947
1948 // Push return address
1949 ppush(out);
1950 }
1951
1952 // This is used to parse the signature for fields, since they are very simple...
1953 CellTypeState *GenerateOopMap::sigchar_to_effect(char sigch, int bci, CellTypeState *out) {
1954 // Object and array
1955 if (sigch=='L' || sigch=='[') {
1956 out[0] = CellTypeState::make_line_ref(bci);
1957 out[1] = CellTypeState::bottom;
1958 return out;
1959 }
1960 if (sigch == 'J' || sigch == 'D' ) return vvCTS; // Long and Double
1961 if (sigch == 'V' ) return epsilonCTS; // Void
1962 return vCTS; // Otherwise
1963 }
1964
1965 long GenerateOopMap::_total_byte_count = 0;
1966 elapsedTimer GenerateOopMap::_total_oopmap_time;
1967
1968 // This function assumes "bcs" is at a "ret" instruction and that the vars
1969 // state is valid for that instruction. Furthermore, the ret instruction
1970 // must be the last instruction in "bb" (we store information about the
1971 // "ret" in "bb").
1972 void GenerateOopMap::ret_jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int varNo, int *data) {
1973 CellTypeState ra = vars()[varNo];
1974 if (!ra.is_good_address()) {
1975 verify_error("ret returns from two jsr subroutines?");
1976 return;
1977 }
1978 int target = ra.get_info();
1979
1980 RetTableEntry* rtEnt = _rt.find_jsrs_for_target(target);
1981 int bci = bcs->bci();
1982 for (int i = 0; i < rtEnt->nof_jsrs(); i++) {
1983 int target_bci = rtEnt->jsrs(i);
1984 // Make sure a jrtRet does not set the changed bit for dead basicblock.
1985 BasicBlock* jsr_bb = get_basic_block_containing(target_bci - 1);
1986 debug_only(BasicBlock* target_bb = &jsr_bb[1];)
1987 assert(target_bb == get_basic_block_at(target_bci), "wrong calc. of successor basicblock");
1988 bool alive = jsr_bb->is_alive();
1989 if (TraceNewOopMapGeneration) {
1990 tty->print("pc = %d, ret -> %d alive: %s\n", bci, target_bci, alive ? "true" : "false");
1991 }
1992 if (alive) jmpFct(this, target_bci, data);
1993 }
1994 }
1995
1996 //
1997 // Debug method
1998 //
1999 char* GenerateOopMap::state_vec_to_string(CellTypeState* vec, int len) {
2000 #ifdef ASSERT
2001 int checklen = MAX3(_max_locals, _max_stack, _max_monitors) + 1;
2002 assert(len < checklen, "state_vec_buf overflow");
2003 #endif
2004 for (int i = 0; i < len; i++) _state_vec_buf[i] = vec[i].to_char();
2005 _state_vec_buf[len] = 0;
2006 return _state_vec_buf;
2007 }
2008
2009 void GenerateOopMap::print_time() {
2010 tty->print_cr ("Accumulated oopmap times:");
2011 tty->print_cr ("---------------------------");
2012 tty->print_cr (" Total : %3.3f sec.", GenerateOopMap::_total_oopmap_time.seconds());
2013 tty->print_cr (" (%3.0f bytecodes per sec) ",
2014 GenerateOopMap::_total_byte_count / GenerateOopMap::_total_oopmap_time.seconds());
2015 }
2016
2017 //
2018 // ============ Main Entry Point ===========
2019 //
2020 GenerateOopMap::GenerateOopMap(methodHandle method) {
2021 // We have to initialize all variables here, that can be queried direcly
2022 _method = method;
2023 _max_locals=0;
2024 _init_vars = NULL;
2025
2026 #ifndef PRODUCT
2027 // If we are doing a detailed trace, include the regular trace information.
2028 if (TraceNewOopMapGenerationDetailed) {
2029 TraceNewOopMapGeneration = true;
2030 }
2031 #endif
2032 }
2033
2034 void GenerateOopMap::compute_map(TRAPS) {
2035 #ifndef PRODUCT
2036 if (TimeOopMap2) {
2037 method()->print_short_name(tty);
2038 tty->print(" ");
2039 }
2040 if (TimeOopMap) {
2041 _total_byte_count += method()->code_size();
2042 }
2043 #endif
2044 TraceTime t_single("oopmap time", TimeOopMap2);
2045 TraceTime t_all(NULL, &_total_oopmap_time, TimeOopMap);
2046
2047 // Initialize values
2048 _got_error = false;
2049 _conflict = false;
2050 _max_locals = method()->max_locals();
2051 _max_stack = method()->max_stack();
2052 _has_exceptions = (method()->exception_table()->length() > 0);
2053 _nof_refval_conflicts = 0;
2054 _init_vars = new GrowableArray<intptr_t>(5); // There are seldom more than 5 init_vars
2055 _report_result = false;
2056 _report_result_for_send = false;
2057 _new_var_map = NULL;
2058 _ret_adr_tos = new GrowableArray<intptr_t>(5); // 5 seems like a good number;
2059 _did_rewriting = false;
2060 _did_relocation = false;
2061
2062 if (TraceNewOopMapGeneration) {
2063 tty->print("Method name: %s\n", method()->name()->as_C_string());
2064 if (Verbose) {
2065 _method->print_codes();
2066 tty->print_cr("Exception table:");
2067 typeArrayOop excps = method()->exception_table();
2068 for(int i = 0; i < excps->length(); i += 4) {
2069 tty->print_cr("[%d - %d] -> %d", excps->int_at(i + 0), excps->int_at(i + 1), excps->int_at(i + 2));
2070 }
2071 }
2072 }
2073
2074 // if no code - do nothing
2075 // compiler needs info
2076 if (method()->code_size() == 0 || _max_locals + method()->max_stack() == 0) {
2077 fill_stackmap_prolog(0);
2078 fill_stackmap_epilog();
2079 return;
2080 }
2081 // Step 1: Compute all jump targets and their return value
2082 if (!_got_error)
2083 _rt.compute_ret_table(_method);
2084
2085 // Step 2: Find all basic blocks and count GC points
2086 if (!_got_error)
2087 mark_bbheaders_and_count_gc_points();
2088
2089 // Step 3: Calculate stack maps
2090 if (!_got_error)
2091 do_interpretation();
2092
2093 // Step 4:Return results
2094 if (!_got_error && report_results())
2095 report_result();
2096
2097 if (_got_error) {
2098 THROW_HANDLE(_exception);
2099 }
2100 }
2101
2102 // Error handling methods
2103 // These methods create an exception for the current thread which is thrown
2104 // at the bottom of the call stack, when it returns to compute_map(). The
2105 // _got_error flag controls execution. NOT TODO: The VM exception propagation
2106 // mechanism using TRAPS/CHECKs could be used here instead but it would need
2107 // to be added as a parameter to every function and checked for every call.
2108 // The tons of extra code it would generate didn't seem worth the change.
2109 //
2110 void GenerateOopMap::error_work(const char *format, va_list ap) {
2111 _got_error = true;
2112 char msg_buffer[512];
2113 vsnprintf(msg_buffer, sizeof(msg_buffer), format, ap);
2114 // Append method name
2115 char msg_buffer2[512];
2116 jio_snprintf(msg_buffer2, sizeof(msg_buffer2), "%s in method %s", msg_buffer, method()->name()->as_C_string());
2117 _exception = Exceptions::new_exception(Thread::current(),
2118 vmSymbols::java_lang_LinkageError(), msg_buffer2);
2119 }
2120
2121 void GenerateOopMap::report_error(const char *format, ...) {
2122 va_list ap;
2123 va_start(ap, format);
2124 error_work(format, ap);
2125 }
2126
2127 void GenerateOopMap::verify_error(const char *format, ...) {
2128 // We do not distinguish between different types of errors for verification
2129 // errors. Let the verifier give a better message.
2130 const char *msg = "Illegal class file encountered. Try running with -Xverify:all";
2131 error_work(msg, NULL);
2132 }
2133
2134 //
2135 // Report result opcodes
2136 //
2137 void GenerateOopMap::report_result() {
2138
2139 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass");
2140
2141 // We now want to report the result of the parse
2142 _report_result = true;
2143
2144 // Prolog code
2145 fill_stackmap_prolog(_gc_points);
2146
2147 // Mark everything changed, then do one interpretation pass.
2148 for (int i = 0; i<_bb_count; i++) {
2149 if (_basic_blocks[i].is_reachable()) {
2150 _basic_blocks[i].set_changed(true);
2151 interp_bb(&_basic_blocks[i]);
2152 }
2153 }
2154
2155 // Note: Since we are skipping dead-code when we are reporting results, then
2156 // the no. of encountered gc-points might be fewer than the previously number
2157 // we have counted. (dead-code is a pain - it should be removed before we get here)
2158 fill_stackmap_epilog();
2159
2160 // Report initvars
2161 fill_init_vars(_init_vars);
2162
2163 _report_result = false;
2164 }
2165
2166 void GenerateOopMap::result_for_basicblock(int bci) {
2167 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass for basicblock");
2168
2169 // We now want to report the result of the parse
2170 _report_result = true;
2171
2172 // Find basicblock and report results
2173 BasicBlock* bb = get_basic_block_containing(bci);
2174 assert(bb->is_reachable(), "getting result from unreachable basicblock");
2175 bb->set_changed(true);
2176 interp_bb(bb);
2177 }
2178
2179 //
2180 // Conflict handling code
2181 //
2182
2183 void GenerateOopMap::record_refval_conflict(int varNo) {
2184 assert(varNo>=0 && varNo< _max_locals, "index out of range");
2185
2186 if (TraceOopMapRewrites) {
2187 tty->print("### Conflict detected (local no: %d)\n", varNo);
2188 }
2189
2190 if (!_new_var_map) {
2191 _new_var_map = NEW_RESOURCE_ARRAY(int, _max_locals);
2192 for (int k = 0; k < _max_locals; k++) _new_var_map[k] = k;
2193 }
2194
2195 if ( _new_var_map[varNo] == varNo) {
2196 // Check if max. number of locals has been reached
2197 if (_max_locals + _nof_refval_conflicts >= MAX_LOCAL_VARS) {
2198 report_error("Rewriting exceeded local variable limit");
2199 return;
2200 }
2201 _new_var_map[varNo] = _max_locals + _nof_refval_conflicts;
2202 _nof_refval_conflicts++;
2203 }
2204 }
2205
2206 void GenerateOopMap::rewrite_refval_conflicts()
2207 {
2208 // We can get here two ways: Either a rewrite conflict was detected, or
2209 // an uninitialize reference was detected. In the second case, we do not
2210 // do any rewriting, we just want to recompute the reference set with the
2211 // new information
2212
2213 int nof_conflicts = 0; // Used for debugging only
2214
2215 if ( _nof_refval_conflicts == 0 )
2216 return;
2217
2218 // Check if rewrites are allowed in this parse.
2219 if (!allow_rewrites() && !IgnoreRewrites) {
2220 fatal("Rewriting method not allowed at this stage");
2221 }
2222
2223
2224 // This following flag is to tempoary supress rewrites. The locals that might conflict will
2225 // all be set to contain values. This is UNSAFE - however, until the rewriting has been completely
2226 // tested it is nice to have.
2227 if (IgnoreRewrites) {
2228 if (Verbose) {
2229 tty->print("rewrites suppressed for local no. ");
2230 for (int l = 0; l < _max_locals; l++) {
2231 if (_new_var_map[l] != l) {
2232 tty->print("%d ", l);
2233 vars()[l] = CellTypeState::value;
2234 }
2235 }
2236 tty->cr();
2237 }
2238
2239 // That was that...
2240 _new_var_map = NULL;
2241 _nof_refval_conflicts = 0;
2242 _conflict = false;
2243
2244 return;
2245 }
2246
2247 // Tracing flag
2248 _did_rewriting = true;
2249
2250 if (TraceOopMapRewrites) {
2251 tty->print_cr("ref/value conflict for method %s - bytecodes are getting rewritten", method()->name()->as_C_string());
2252 method()->print();
2253 method()->print_codes();
2254 }
2255
2256 assert(_new_var_map!=NULL, "nothing to rewrite");
2257 assert(_conflict==true, "We should not be here");
2258
2259 compute_ret_adr_at_TOS();
2260 if (!_got_error) {
2261 for (int k = 0; k < _max_locals && !_got_error; k++) {
2262 if (_new_var_map[k] != k) {
2263 if (TraceOopMapRewrites) {
2264 tty->print_cr("Rewriting: %d -> %d", k, _new_var_map[k]);
2265 }
2266 rewrite_refval_conflict(k, _new_var_map[k]);
2267 if (_got_error) return;
2268 nof_conflicts++;
2269 }
2270 }
2271 }
2272
2273 assert(nof_conflicts == _nof_refval_conflicts, "sanity check");
2274
2275 // Adjust the number of locals
2276 method()->set_max_locals(_max_locals+_nof_refval_conflicts);
2277 _max_locals += _nof_refval_conflicts;
2278
2279 // That was that...
2280 _new_var_map = NULL;
2281 _nof_refval_conflicts = 0;
2282 }
2283
2284 void GenerateOopMap::rewrite_refval_conflict(int from, int to) {
2285 bool startOver;
2286 do {
2287 // Make sure that the BytecodeStream is constructed in the loop, since
2288 // during rewriting a new method oop is going to be used, and the next time
2289 // around we want to use that.
2290 BytecodeStream bcs(_method);
2291 startOver = false;
2292
2293 while( bcs.next() >=0 && !startOver && !_got_error) {
2294 startOver = rewrite_refval_conflict_inst(&bcs, from, to);
2295 }
2296 } while (startOver && !_got_error);
2297 }
2298
2299 /* If the current instruction is one that uses local variable "from"
2300 in a ref way, change it to use "to". There's a subtle reason why we
2301 renumber the ref uses and not the non-ref uses: non-ref uses may be
2302 2 slots wide (double, long) which would necessitate keeping track of
2303 whether we should add one or two variables to the method. If the change
2304 affected the width of some instruction, returns "TRUE"; otherwise, returns "FALSE".
2305 Another reason for moving ref's value is for solving (addr, ref) conflicts, which
2306 both uses aload/astore methods.
2307 */
2308 bool GenerateOopMap::rewrite_refval_conflict_inst(BytecodeStream *itr, int from, int to) {
2309 Bytecodes::Code bc = itr->code();
2310 int index;
2311 int bci = itr->bci();
2312
2313 if (is_aload(itr, &index) && index == from) {
2314 if (TraceOopMapRewrites) {
2315 tty->print_cr("Rewriting aload at bci: %d", bci);
2316 }
2317 return rewrite_load_or_store(itr, Bytecodes::_aload, Bytecodes::_aload_0, to);
2318 }
2319
2320 if (is_astore(itr, &index) && index == from) {
2321 if (!stack_top_holds_ret_addr(bci)) {
2322 if (TraceOopMapRewrites) {
2323 tty->print_cr("Rewriting astore at bci: %d", bci);
2324 }
2325 return rewrite_load_or_store(itr, Bytecodes::_astore, Bytecodes::_astore_0, to);
2326 } else {
2327 if (TraceOopMapRewrites) {
2328 tty->print_cr("Supress rewriting of astore at bci: %d", bci);
2329 }
2330 }
2331 }
2332
2333 return false;
2334 }
2335
2336 // The argument to this method is:
2337 // bc : Current bytecode
2338 // bcN : either _aload or _astore
2339 // bc0 : either _aload_0 or _astore_0
2340 bool GenerateOopMap::rewrite_load_or_store(BytecodeStream *bcs, Bytecodes::Code bcN, Bytecodes::Code bc0, unsigned int varNo) {
2341 assert(bcN == Bytecodes::_astore || bcN == Bytecodes::_aload, "wrong argument (bcN)");
2342 assert(bc0 == Bytecodes::_astore_0 || bc0 == Bytecodes::_aload_0, "wrong argument (bc0)");
2343 int ilen = Bytecodes::length_at(bcs->bcp());
2344 int newIlen;
2345
2346 if (ilen == 4) {
2347 // Original instruction was wide; keep it wide for simplicity
2348 newIlen = 4;
2349 } else if (varNo < 4)
2350 newIlen = 1;
2351 else if (varNo >= 256)
2352 newIlen = 4;
2353 else
2354 newIlen = 2;
2355
2356 // If we need to relocate in order to patch the byte, we
2357 // do the patching in a temp. buffer, that is passed to the reloc.
2358 // The patching of the bytecode stream is then done by the Relocator.
2359 // This is neccesary, since relocating the instruction at a certain bci, might
2360 // also relocate that instruction, e.g., if a _goto before it gets widen to a _goto_w.
2361 // Hence, we do not know which bci to patch after relocation.
2362
2363 assert(newIlen <= 4, "sanity check");
2364 u_char inst_buffer[4]; // Max. instruction size is 4.
2365 address bcp;
2366
2367 if (newIlen != ilen) {
2368 // Relocation needed do patching in temp. buffer
2369 bcp = (address)inst_buffer;
2370 } else {
2371 bcp = _method->bcp_from(bcs->bci());
2372 }
2373
2374 // Patch either directly in methodOop or in temp. buffer
2375 if (newIlen == 1) {
2376 assert(varNo < 4, "varNo too large");
2377 *bcp = bc0 + varNo;
2378 } else if (newIlen == 2) {
2379 assert(varNo < 256, "2-byte index needed!");
2380 *(bcp + 0) = bcN;
2381 *(bcp + 1) = varNo;
2382 } else {
2383 assert(newIlen == 4, "Wrong instruction length");
2384 *(bcp + 0) = Bytecodes::_wide;
2385 *(bcp + 1) = bcN;
2386 Bytes::put_Java_u2(bcp+2, varNo);
2387 }
2388
2389 if (newIlen != ilen) {
2390 expand_current_instr(bcs->bci(), ilen, newIlen, inst_buffer);
2391 }
2392
2393
2394 return (newIlen != ilen);
2395 }
2396
2397 class RelocCallback : public RelocatorListener {
2398 private:
2399 GenerateOopMap* _gom;
2400 public:
2401 RelocCallback(GenerateOopMap* gom) { _gom = gom; };
2402
2403 // Callback method
2404 virtual void relocated(int bci, int delta, int new_code_length) {
2405 _gom->update_basic_blocks (bci, delta, new_code_length);
2406 _gom->update_ret_adr_at_TOS(bci, delta);
2407 _gom->_rt.update_ret_table (bci, delta);
2408 }
2409 };
2410
2411 // Returns true if expanding was succesful. Otherwise, reports an error and
2412 // returns false.
2413 void GenerateOopMap::expand_current_instr(int bci, int ilen, int newIlen, u_char inst_buffer[]) {
2414 Thread *THREAD = Thread::current(); // Could really have TRAPS argument.
2415 RelocCallback rcb(this);
2416 Relocator rc(_method, &rcb);
2417 methodHandle m= rc.insert_space_at(bci, newIlen, inst_buffer, THREAD);
2418 if (m.is_null() || HAS_PENDING_EXCEPTION) {
2419 report_error("could not rewrite method - exception occurred or bytecode buffer overflow");
2420 return;
2421 }
2422
2423 // Relocator returns a new method oop.
2424 _did_relocation = true;
2425 _method = m;
2426 }
2427
2428
2429 bool GenerateOopMap::is_astore(BytecodeStream *itr, int *index) {
2430 Bytecodes::Code bc = itr->code();
2431 switch(bc) {
2432 case Bytecodes::_astore_0:
2433 case Bytecodes::_astore_1:
2434 case Bytecodes::_astore_2:
2435 case Bytecodes::_astore_3:
2436 *index = bc - Bytecodes::_astore_0;
2437 return true;
2438 case Bytecodes::_astore:
2439 *index = itr->get_index();
2440 return true;
2441 }
2442 return false;
2443 }
2444
2445 bool GenerateOopMap::is_aload(BytecodeStream *itr, int *index) {
2446 Bytecodes::Code bc = itr->code();
2447 switch(bc) {
2448 case Bytecodes::_aload_0:
2449 case Bytecodes::_aload_1:
2450 case Bytecodes::_aload_2:
2451 case Bytecodes::_aload_3:
2452 *index = bc - Bytecodes::_aload_0;
2453 return true;
2454
2455 case Bytecodes::_aload:
2456 *index = itr->get_index();
2457 return true;
2458 }
2459 return false;
2460 }
2461
2462
2463 // Return true iff the top of the operand stack holds a return address at
2464 // the current instruction
2465 bool GenerateOopMap::stack_top_holds_ret_addr(int bci) {
2466 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2467 if (_ret_adr_tos->at(i) == bci)
2468 return true;
2469 }
2470
2471 return false;
2472 }
2473
2474 void GenerateOopMap::compute_ret_adr_at_TOS() {
2475 assert(_ret_adr_tos != NULL, "must be initialized");
2476 _ret_adr_tos->clear();
2477
2478 for (int i = 0; i < bb_count(); i++) {
2479 BasicBlock* bb = &_basic_blocks[i];
2480
2481 // Make sure to only check basicblocks that are reachable
2482 if (bb->is_reachable()) {
2483
2484 // For each Basic block we check all instructions
2485 BytecodeStream bcs(_method);
2486 bcs.set_interval(bb->_bci, next_bb_start_pc(bb));
2487
2488 restore_state(bb);
2489
2490 while (bcs.next()>=0 && !_got_error) {
2491 // TDT: should this be is_good_address() ?
2492 if (_stack_top > 0 && stack()[_stack_top-1].is_address()) {
2493 _ret_adr_tos->append(bcs.bci());
2494 if (TraceNewOopMapGeneration) {
2495 tty->print_cr("Ret_adr TOS at bci: %d", bcs.bci());
2496 }
2497 }
2498 interp1(&bcs);
2499 }
2500 }
2501 }
2502 }
2503
2504 void GenerateOopMap::update_ret_adr_at_TOS(int bci, int delta) {
2505 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2506 int v = _ret_adr_tos->at(i);
2507 if (v > bci) _ret_adr_tos->at_put(i, v + delta);
2508 }
2509 }
2510
2511 // ===================================================================
2512
2513 #ifndef PRODUCT
2514 int ResolveOopMapConflicts::_nof_invocations = 0;
2515 int ResolveOopMapConflicts::_nof_rewrites = 0;
2516 int ResolveOopMapConflicts::_nof_relocations = 0;
2517 #endif
2518
2519 methodHandle ResolveOopMapConflicts::do_potential_rewrite(TRAPS) {
2520 compute_map(CHECK_(methodHandle()));
2521
2522 #ifndef PRODUCT
2523 // Tracking and statistics
2524 if (PrintRewrites) {
2525 _nof_invocations++;
2526 if (did_rewriting()) {
2527 _nof_rewrites++;
2528 if (did_relocation()) _nof_relocations++;
2529 tty->print("Method was rewritten %s: ", (did_relocation()) ? "and relocated" : "");
2530 method()->print_value(); tty->cr();
2531 tty->print_cr("Cand.: %d rewrts: %d (%d%%) reloc.: %d (%d%%)",
2532 _nof_invocations,
2533 _nof_rewrites, (_nof_rewrites * 100) / _nof_invocations,
2534 _nof_relocations, (_nof_relocations * 100) / _nof_invocations);
2535 }
2536 }
2537 #endif
2538 return methodHandle(THREAD, method());
2539 }
2540