Print this page
| Split |
Close |
| Expand all |
| Collapse all |
--- old/src/share/vm/c1/c1_IR.cpp
+++ new/src/share/vm/c1/c1_IR.cpp
1 1 /*
2 - * Copyright 1999-2009 Sun Microsystems, Inc. All Rights Reserved.
2 + * Copyright 1999-2010 Sun Microsystems, Inc. All Rights Reserved.
3 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 4 *
5 5 * This code is free software; you can redistribute it and/or modify it
6 6 * under the terms of the GNU General Public License version 2 only, as
7 7 * published by the Free Software Foundation.
8 8 *
9 9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 12 * version 2 for more details (a copy is included in the LICENSE file that
13 13 * accompanied this code).
14 14 *
15 15 * You should have received a copy of the GNU General Public License version
16 16 * 2 along with this work; if not, write to the Free Software Foundation,
17 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 18 *
19 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 21 * have any questions.
22 22 *
23 23 */
24 24
25 25 # include "incls/_precompiled.incl"
26 26 # include "incls/_c1_IR.cpp.incl"
27 27
28 28
29 29 // Implementation of XHandlers
30 30 //
31 31 // Note: This code could eventually go away if we are
32 32 // just using the ciExceptionHandlerStream.
33 33
34 34 XHandlers::XHandlers(ciMethod* method) : _list(method->exception_table_length()) {
35 35 ciExceptionHandlerStream s(method);
36 36 while (!s.is_done()) {
37 37 _list.append(new XHandler(s.handler()));
38 38 s.next();
39 39 }
40 40 assert(s.count() == method->exception_table_length(), "exception table lengths inconsistent");
41 41 }
42 42
43 43 // deep copy of all XHandler contained in list
44 44 XHandlers::XHandlers(XHandlers* other) :
45 45 _list(other->length())
46 46 {
47 47 for (int i = 0; i < other->length(); i++) {
48 48 _list.append(new XHandler(other->handler_at(i)));
49 49 }
50 50 }
51 51
52 52 // Returns whether a particular exception type can be caught. Also
53 53 // returns true if klass is unloaded or any exception handler
54 54 // classes are unloaded. type_is_exact indicates whether the throw
55 55 // is known to be exactly that class or it might throw a subtype.
56 56 bool XHandlers::could_catch(ciInstanceKlass* klass, bool type_is_exact) const {
57 57 // the type is unknown so be conservative
58 58 if (!klass->is_loaded()) {
59 59 return true;
60 60 }
61 61
62 62 for (int i = 0; i < length(); i++) {
63 63 XHandler* handler = handler_at(i);
64 64 if (handler->is_catch_all()) {
65 65 // catch of ANY
66 66 return true;
67 67 }
68 68 ciInstanceKlass* handler_klass = handler->catch_klass();
69 69 // if it's unknown it might be catchable
70 70 if (!handler_klass->is_loaded()) {
71 71 return true;
72 72 }
73 73 // if the throw type is definitely a subtype of the catch type
74 74 // then it can be caught.
75 75 if (klass->is_subtype_of(handler_klass)) {
76 76 return true;
77 77 }
78 78 if (!type_is_exact) {
79 79 // If the type isn't exactly known then it can also be caught by
80 80 // catch statements where the inexact type is a subtype of the
81 81 // catch type.
82 82 // given: foo extends bar extends Exception
83 83 // throw bar can be caught by catch foo, catch bar, and catch
84 84 // Exception, however it can't be caught by any handlers without
85 85 // bar in its type hierarchy.
86 86 if (handler_klass->is_subtype_of(klass)) {
87 87 return true;
88 88 }
89 89 }
90 90 }
91 91
92 92 return false;
93 93 }
94 94
95 95
96 96 bool XHandlers::equals(XHandlers* others) const {
97 97 if (others == NULL) return false;
98 98 if (length() != others->length()) return false;
99 99
100 100 for (int i = 0; i < length(); i++) {
101 101 if (!handler_at(i)->equals(others->handler_at(i))) return false;
102 102 }
103 103 return true;
104 104 }
105 105
106 106 bool XHandler::equals(XHandler* other) const {
107 107 assert(entry_pco() != -1 && other->entry_pco() != -1, "must have entry_pco");
108 108
109 109 if (entry_pco() != other->entry_pco()) return false;
110 110 if (scope_count() != other->scope_count()) return false;
111 111 if (_desc != other->_desc) return false;
112 112
113 113 assert(entry_block() == other->entry_block(), "entry_block must be equal when entry_pco is equal");
114 114 return true;
115 115 }
116 116
117 117
118 118 // Implementation of IRScope
119 119
120 120 BlockBegin* IRScope::header_block(BlockBegin* entry, BlockBegin::Flag f, ValueStack* state) {
121 121 if (entry == NULL) return NULL;
122 122 assert(entry->is_set(f), "entry/flag mismatch");
123 123 // create header block
124 124 BlockBegin* h = new BlockBegin(entry->bci());
125 125 BlockEnd* g = new Goto(entry, false);
126 126 h->set_next(g, entry->bci());
127 127 h->set_end(g);
128 128 h->set(f);
129 129 // setup header block end state
130 130 ValueStack* s = state->copy(); // can use copy since stack is empty (=> no phis)
131 131 assert(s->stack_is_empty(), "must have empty stack at entry point");
132 132 g->set_state(s);
133 133 return h;
134 134 }
135 135
136 136
137 137 BlockBegin* IRScope::build_graph(Compilation* compilation, int osr_bci) {
138 138 GraphBuilder gm(compilation, this);
139 139 NOT_PRODUCT(if (PrintValueNumbering && Verbose) gm.print_stats());
140 140 if (compilation->bailed_out()) return NULL;
141 141 return gm.start();
142 142 }
143 143
144 144
145 145 IRScope::IRScope(Compilation* compilation, IRScope* caller, int caller_bci, ciMethod* method, int osr_bci, bool create_graph)
146 146 : _callees(2)
147 147 , _compilation(compilation)
148 148 , _lock_stack_size(-1)
149 149 , _requires_phi_function(method->max_locals())
150 150 {
151 151 _caller = caller;
152 152 _caller_bci = caller == NULL ? -1 : caller_bci;
153 153 _caller_state = NULL; // Must be set later if needed
154 154 _level = caller == NULL ? 0 : caller->level() + 1;
155 155 _method = method;
156 156 _xhandlers = new XHandlers(method);
157 157 _number_of_locks = 0;
158 158 _monitor_pairing_ok = method->has_balanced_monitors();
159 159 _start = NULL;
160 160
161 161 if (osr_bci == -1) {
162 162 _requires_phi_function.clear();
163 163 } else {
164 164 // selective creation of phi functions is not possibel in osr-methods
165 165 _requires_phi_function.set_range(0, method->max_locals());
166 166 }
167 167
168 168 assert(method->holder()->is_loaded() , "method holder must be loaded");
169 169
170 170 // build graph if monitor pairing is ok
171 171 if (create_graph && monitor_pairing_ok()) _start = build_graph(compilation, osr_bci);
172 172 }
173 173
174 174
175 175 int IRScope::max_stack() const {
176 176 int my_max = method()->max_stack();
177 177 int callee_max = 0;
178 178 for (int i = 0; i < number_of_callees(); i++) {
179 179 callee_max = MAX2(callee_max, callee_no(i)->max_stack());
180 180 }
181 181 return my_max + callee_max;
182 182 }
183 183
184 184
185 185 void IRScope::compute_lock_stack_size() {
186 186 if (!InlineMethodsWithExceptionHandlers) {
187 187 _lock_stack_size = 0;
188 188 return;
189 189 }
190 190
191 191 // Figure out whether we have to preserve expression stack elements
192 192 // for parent scopes, and if so, how many
193 193 IRScope* cur_scope = this;
194 194 while (cur_scope != NULL && !cur_scope->xhandlers()->has_handlers()) {
195 195 cur_scope = cur_scope->caller();
196 196 }
197 197 _lock_stack_size = (cur_scope == NULL ? 0 :
198 198 (cur_scope->caller_state() == NULL ? 0 :
199 199 cur_scope->caller_state()->stack_size()));
200 200 }
201 201
202 202 int IRScope::top_scope_bci() const {
203 203 assert(!is_top_scope(), "no correct answer for top scope possible");
204 204 const IRScope* scope = this;
205 205 while (!scope->caller()->is_top_scope()) {
206 206 scope = scope->caller();
207 207 }
208 208 return scope->caller_bci();
209 209 }
210 210
211 211 bool IRScopeDebugInfo::should_reexecute() {
212 212 ciMethod* cur_method = scope()->method();
213 213 int cur_bci = bci();
214 214 if (cur_method != NULL && cur_bci != SynchronizationEntryBCI) {
215 215 Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
216 216 return Interpreter::bytecode_should_reexecute(code);
217 217 } else
218 218 return false;
219 219 }
220 220
221 221
222 222 // Implementation of CodeEmitInfo
223 223
224 224 // Stack must be NON-null
225 225 CodeEmitInfo::CodeEmitInfo(int bci, ValueStack* stack, XHandlers* exception_handlers)
226 226 : _scope(stack->scope())
227 227 , _bci(bci)
228 228 , _scope_debug_info(NULL)
229 229 , _oop_map(NULL)
230 230 , _stack(stack)
231 231 , _exception_handlers(exception_handlers)
232 232 , _next(NULL)
233 233 , _id(-1) {
234 234 assert(_stack != NULL, "must be non null");
235 235 assert(_bci == SynchronizationEntryBCI || Bytecodes::is_defined(scope()->method()->java_code_at_bci(_bci)), "make sure bci points at a real bytecode");
236 236 }
237 237
238 238
239 239 CodeEmitInfo::CodeEmitInfo(CodeEmitInfo* info, bool lock_stack_only)
240 240 : _scope(info->_scope)
241 241 , _exception_handlers(NULL)
242 242 , _bci(info->_bci)
243 243 , _scope_debug_info(NULL)
244 244 , _oop_map(NULL) {
245 245 if (lock_stack_only) {
246 246 if (info->_stack != NULL) {
247 247 _stack = info->_stack->copy_locks();
248 248 } else {
249 249 _stack = NULL;
250 250 }
251 251 } else {
|
↓ open down ↓ |
239 lines elided |
↑ open up ↑ |
252 252 _stack = info->_stack;
253 253 }
254 254
255 255 // deep copy of exception handlers
256 256 if (info->_exception_handlers != NULL) {
257 257 _exception_handlers = new XHandlers(info->_exception_handlers);
258 258 }
259 259 }
260 260
261 261
262 -void CodeEmitInfo::record_debug_info(DebugInformationRecorder* recorder, int pc_offset) {
262 +void CodeEmitInfo::record_debug_info(DebugInformationRecorder* recorder, int pc_offset, bool is_method_handle_invoke) {
263 263 // record the safepoint before recording the debug info for enclosing scopes
264 264 recorder->add_safepoint(pc_offset, _oop_map->deep_copy());
265 - _scope_debug_info->record_debug_info(recorder, pc_offset, true/*topmost*/);
265 + _scope_debug_info->record_debug_info(recorder, pc_offset, true/*topmost*/, is_method_handle_invoke);
266 266 recorder->end_safepoint(pc_offset);
267 267 }
268 268
269 269
270 270 void CodeEmitInfo::add_register_oop(LIR_Opr opr) {
271 271 assert(_oop_map != NULL, "oop map must already exist");
272 272 assert(opr->is_single_cpu(), "should not call otherwise");
273 273
274 274 int frame_size = frame_map()->framesize();
275 275 int arg_count = frame_map()->oop_map_arg_count();
276 276 VMReg name = frame_map()->regname(opr);
277 277 _oop_map->set_oop(name);
278 278 }
279 279
280 280
281 281
282 282
283 283 // Implementation of IR
284 284
285 285 IR::IR(Compilation* compilation, ciMethod* method, int osr_bci) :
286 286 _locals_size(in_WordSize(-1))
287 287 , _num_loops(0) {
288 288 // initialize data structures
289 289 ValueType::initialize();
290 290 Instruction::initialize();
291 291 BlockBegin::initialize();
292 292 GraphBuilder::initialize();
293 293 // setup IR fields
294 294 _compilation = compilation;
295 295 _top_scope = new IRScope(compilation, NULL, -1, method, osr_bci, true);
296 296 _code = NULL;
297 297 }
298 298
299 299
300 300 void IR::optimize() {
301 301 Optimizer opt(this);
302 302 if (DoCEE) {
303 303 opt.eliminate_conditional_expressions();
304 304 #ifndef PRODUCT
305 305 if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after CEE"); print(true); }
306 306 if (PrintIR || PrintIR1 ) { tty->print_cr("IR after CEE"); print(false); }
307 307 #endif
308 308 }
309 309 if (EliminateBlocks) {
310 310 opt.eliminate_blocks();
311 311 #ifndef PRODUCT
312 312 if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after block elimination"); print(true); }
313 313 if (PrintIR || PrintIR1 ) { tty->print_cr("IR after block elimination"); print(false); }
314 314 #endif
315 315 }
316 316 if (EliminateNullChecks) {
317 317 opt.eliminate_null_checks();
318 318 #ifndef PRODUCT
319 319 if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after null check elimination"); print(true); }
320 320 if (PrintIR || PrintIR1 ) { tty->print_cr("IR after null check elimination"); print(false); }
321 321 #endif
322 322 }
323 323 }
324 324
325 325
326 326 static int sort_pairs(BlockPair** a, BlockPair** b) {
327 327 if ((*a)->from() == (*b)->from()) {
328 328 return (*a)->to()->block_id() - (*b)->to()->block_id();
329 329 } else {
330 330 return (*a)->from()->block_id() - (*b)->from()->block_id();
331 331 }
332 332 }
333 333
334 334
335 335 class CriticalEdgeFinder: public BlockClosure {
336 336 BlockPairList blocks;
337 337 IR* _ir;
338 338
339 339 public:
340 340 CriticalEdgeFinder(IR* ir): _ir(ir) {}
341 341 void block_do(BlockBegin* bb) {
342 342 BlockEnd* be = bb->end();
343 343 int nos = be->number_of_sux();
344 344 if (nos >= 2) {
345 345 for (int i = 0; i < nos; i++) {
346 346 BlockBegin* sux = be->sux_at(i);
347 347 if (sux->number_of_preds() >= 2) {
348 348 blocks.append(new BlockPair(bb, sux));
349 349 }
350 350 }
351 351 }
352 352 }
353 353
354 354 void split_edges() {
355 355 BlockPair* last_pair = NULL;
356 356 blocks.sort(sort_pairs);
357 357 for (int i = 0; i < blocks.length(); i++) {
358 358 BlockPair* pair = blocks.at(i);
359 359 if (last_pair != NULL && pair->is_same(last_pair)) continue;
360 360 BlockBegin* from = pair->from();
361 361 BlockBegin* to = pair->to();
362 362 BlockBegin* split = from->insert_block_between(to);
363 363 #ifndef PRODUCT
364 364 if ((PrintIR || PrintIR1) && Verbose) {
365 365 tty->print_cr("Split critical edge B%d -> B%d (new block B%d)",
366 366 from->block_id(), to->block_id(), split->block_id());
367 367 }
368 368 #endif
369 369 last_pair = pair;
370 370 }
371 371 }
372 372 };
373 373
374 374 void IR::split_critical_edges() {
375 375 CriticalEdgeFinder cef(this);
376 376
377 377 iterate_preorder(&cef);
378 378 cef.split_edges();
379 379 }
380 380
381 381
382 382 class UseCountComputer: public AllStatic {
383 383 private:
384 384 static void update_use_count(Value* n) {
385 385 // Local instructions and Phis for expression stack values at the
386 386 // start of basic blocks are not added to the instruction list
387 387 if ((*n)->bci() == -99 && (*n)->as_Local() == NULL &&
388 388 (*n)->as_Phi() == NULL) {
389 389 assert(false, "a node was not appended to the graph");
390 390 Compilation::current_compilation()->bailout("a node was not appended to the graph");
391 391 }
392 392 // use n's input if not visited before
393 393 if (!(*n)->is_pinned() && !(*n)->has_uses()) {
394 394 // note: a) if the instruction is pinned, it will be handled by compute_use_count
395 395 // b) if the instruction has uses, it was touched before
396 396 // => in both cases we don't need to update n's values
397 397 uses_do(n);
398 398 }
399 399 // use n
400 400 (*n)->_use_count++;
401 401 }
402 402
403 403 static Values* worklist;
404 404 static int depth;
405 405 enum {
406 406 max_recurse_depth = 20
407 407 };
408 408
409 409 static void uses_do(Value* n) {
410 410 depth++;
411 411 if (depth > max_recurse_depth) {
412 412 // don't allow the traversal to recurse too deeply
413 413 worklist->push(*n);
414 414 } else {
415 415 (*n)->input_values_do(update_use_count);
416 416 // special handling for some instructions
417 417 if ((*n)->as_BlockEnd() != NULL) {
418 418 // note on BlockEnd:
419 419 // must 'use' the stack only if the method doesn't
420 420 // terminate, however, in those cases stack is empty
421 421 (*n)->state_values_do(update_use_count);
422 422 }
423 423 }
424 424 depth--;
425 425 }
426 426
427 427 static void basic_compute_use_count(BlockBegin* b) {
428 428 depth = 0;
429 429 // process all pinned nodes as the roots of expression trees
430 430 for (Instruction* n = b; n != NULL; n = n->next()) {
431 431 if (n->is_pinned()) uses_do(&n);
432 432 }
433 433 assert(depth == 0, "should have counted back down");
434 434
435 435 // now process any unpinned nodes which recursed too deeply
436 436 while (worklist->length() > 0) {
437 437 Value t = worklist->pop();
438 438 if (!t->is_pinned()) {
439 439 // compute the use count
440 440 uses_do(&t);
441 441
442 442 // pin the instruction so that LIRGenerator doesn't recurse
443 443 // too deeply during it's evaluation.
444 444 t->pin();
445 445 }
446 446 }
447 447 assert(depth == 0, "should have counted back down");
448 448 }
449 449
450 450 public:
451 451 static void compute(BlockList* blocks) {
452 452 worklist = new Values();
453 453 blocks->blocks_do(basic_compute_use_count);
454 454 worklist = NULL;
455 455 }
456 456 };
457 457
458 458
459 459 Values* UseCountComputer::worklist = NULL;
460 460 int UseCountComputer::depth = 0;
461 461
462 462 // helper macro for short definition of trace-output inside code
463 463 #ifndef PRODUCT
464 464 #define TRACE_LINEAR_SCAN(level, code) \
465 465 if (TraceLinearScanLevel >= level) { \
466 466 code; \
467 467 }
468 468 #else
469 469 #define TRACE_LINEAR_SCAN(level, code)
470 470 #endif
471 471
472 472 class ComputeLinearScanOrder : public StackObj {
473 473 private:
474 474 int _max_block_id; // the highest block_id of a block
475 475 int _num_blocks; // total number of blocks (smaller than _max_block_id)
476 476 int _num_loops; // total number of loops
477 477 bool _iterative_dominators;// method requires iterative computation of dominatiors
478 478
479 479 BlockList* _linear_scan_order; // the resulting list of blocks in correct order
480 480
481 481 BitMap _visited_blocks; // used for recursive processing of blocks
482 482 BitMap _active_blocks; // used for recursive processing of blocks
483 483 BitMap _dominator_blocks; // temproary BitMap used for computation of dominator
484 484 intArray _forward_branches; // number of incoming forward branches for each block
485 485 BlockList _loop_end_blocks; // list of all loop end blocks collected during count_edges
486 486 BitMap2D _loop_map; // two-dimensional bit set: a bit is set if a block is contained in a loop
487 487 BlockList _work_list; // temporary list (used in mark_loops and compute_order)
488 488
489 489 // accessors for _visited_blocks and _active_blocks
490 490 void init_visited() { _active_blocks.clear(); _visited_blocks.clear(); }
491 491 bool is_visited(BlockBegin* b) const { return _visited_blocks.at(b->block_id()); }
492 492 bool is_active(BlockBegin* b) const { return _active_blocks.at(b->block_id()); }
493 493 void set_visited(BlockBegin* b) { assert(!is_visited(b), "already set"); _visited_blocks.set_bit(b->block_id()); }
494 494 void set_active(BlockBegin* b) { assert(!is_active(b), "already set"); _active_blocks.set_bit(b->block_id()); }
495 495 void clear_active(BlockBegin* b) { assert(is_active(b), "not already"); _active_blocks.clear_bit(b->block_id()); }
496 496
497 497 // accessors for _forward_branches
498 498 void inc_forward_branches(BlockBegin* b) { _forward_branches.at_put(b->block_id(), _forward_branches.at(b->block_id()) + 1); }
499 499 int dec_forward_branches(BlockBegin* b) { _forward_branches.at_put(b->block_id(), _forward_branches.at(b->block_id()) - 1); return _forward_branches.at(b->block_id()); }
500 500
501 501 // accessors for _loop_map
502 502 bool is_block_in_loop (int loop_idx, BlockBegin* b) const { return _loop_map.at(loop_idx, b->block_id()); }
503 503 void set_block_in_loop (int loop_idx, BlockBegin* b) { _loop_map.set_bit(loop_idx, b->block_id()); }
504 504 void clear_block_in_loop(int loop_idx, int block_id) { _loop_map.clear_bit(loop_idx, block_id); }
505 505
506 506 // count edges between blocks
507 507 void count_edges(BlockBegin* cur, BlockBegin* parent);
508 508
509 509 // loop detection
510 510 void mark_loops();
511 511 void clear_non_natural_loops(BlockBegin* start_block);
512 512 void assign_loop_depth(BlockBegin* start_block);
513 513
514 514 // computation of final block order
515 515 BlockBegin* common_dominator(BlockBegin* a, BlockBegin* b);
516 516 void compute_dominator(BlockBegin* cur, BlockBegin* parent);
517 517 int compute_weight(BlockBegin* cur);
518 518 bool ready_for_processing(BlockBegin* cur);
519 519 void sort_into_work_list(BlockBegin* b);
520 520 void append_block(BlockBegin* cur);
521 521 void compute_order(BlockBegin* start_block);
522 522
523 523 // fixup of dominators for non-natural loops
524 524 bool compute_dominators_iter();
525 525 void compute_dominators();
526 526
527 527 // debug functions
528 528 NOT_PRODUCT(void print_blocks();)
529 529 DEBUG_ONLY(void verify();)
530 530
531 531 public:
532 532 ComputeLinearScanOrder(BlockBegin* start_block);
533 533
534 534 // accessors for final result
535 535 BlockList* linear_scan_order() const { return _linear_scan_order; }
536 536 int num_loops() const { return _num_loops; }
537 537 };
538 538
539 539
540 540 ComputeLinearScanOrder::ComputeLinearScanOrder(BlockBegin* start_block) :
541 541 _max_block_id(BlockBegin::number_of_blocks()),
542 542 _num_blocks(0),
543 543 _num_loops(0),
544 544 _iterative_dominators(false),
545 545 _visited_blocks(_max_block_id),
546 546 _active_blocks(_max_block_id),
547 547 _dominator_blocks(_max_block_id),
548 548 _forward_branches(_max_block_id, 0),
549 549 _loop_end_blocks(8),
550 550 _work_list(8),
551 551 _linear_scan_order(NULL), // initialized later with correct size
552 552 _loop_map(0, 0) // initialized later with correct size
553 553 {
554 554 TRACE_LINEAR_SCAN(2, "***** computing linear-scan block order");
555 555
556 556 init_visited();
557 557 count_edges(start_block, NULL);
558 558
559 559 if (_num_loops > 0) {
560 560 mark_loops();
561 561 clear_non_natural_loops(start_block);
562 562 assign_loop_depth(start_block);
563 563 }
564 564
565 565 compute_order(start_block);
566 566 compute_dominators();
567 567
568 568 NOT_PRODUCT(print_blocks());
569 569 DEBUG_ONLY(verify());
570 570 }
571 571
572 572
573 573 // Traverse the CFG:
574 574 // * count total number of blocks
575 575 // * count all incoming edges and backward incoming edges
576 576 // * number loop header blocks
577 577 // * create a list with all loop end blocks
578 578 void ComputeLinearScanOrder::count_edges(BlockBegin* cur, BlockBegin* parent) {
579 579 TRACE_LINEAR_SCAN(3, tty->print_cr("Enter count_edges for block B%d coming from B%d", cur->block_id(), parent != NULL ? parent->block_id() : -1));
580 580 assert(cur->dominator() == NULL, "dominator already initialized");
581 581
582 582 if (is_active(cur)) {
583 583 TRACE_LINEAR_SCAN(3, tty->print_cr("backward branch"));
584 584 assert(is_visited(cur), "block must be visisted when block is active");
585 585 assert(parent != NULL, "must have parent");
586 586
587 587 cur->set(BlockBegin::linear_scan_loop_header_flag);
588 588 cur->set(BlockBegin::backward_branch_target_flag);
589 589
590 590 parent->set(BlockBegin::linear_scan_loop_end_flag);
591 591
592 592 // When a loop header is also the start of an exception handler, then the backward branch is
593 593 // an exception edge. Because such edges are usually critical edges which cannot be split, the
594 594 // loop must be excluded here from processing.
595 595 if (cur->is_set(BlockBegin::exception_entry_flag)) {
596 596 // Make sure that dominators are correct in this weird situation
597 597 _iterative_dominators = true;
598 598 return;
599 599 }
600 600 assert(parent->number_of_sux() == 1 && parent->sux_at(0) == cur,
601 601 "loop end blocks must have one successor (critical edges are split)");
602 602
603 603 _loop_end_blocks.append(parent);
604 604 return;
605 605 }
606 606
607 607 // increment number of incoming forward branches
608 608 inc_forward_branches(cur);
609 609
610 610 if (is_visited(cur)) {
611 611 TRACE_LINEAR_SCAN(3, tty->print_cr("block already visited"));
612 612 return;
613 613 }
614 614
615 615 _num_blocks++;
616 616 set_visited(cur);
617 617 set_active(cur);
618 618
619 619 // recursive call for all successors
620 620 int i;
621 621 for (i = cur->number_of_sux() - 1; i >= 0; i--) {
622 622 count_edges(cur->sux_at(i), cur);
623 623 }
624 624 for (i = cur->number_of_exception_handlers() - 1; i >= 0; i--) {
625 625 count_edges(cur->exception_handler_at(i), cur);
626 626 }
627 627
628 628 clear_active(cur);
629 629
630 630 // Each loop has a unique number.
631 631 // When multiple loops are nested, assign_loop_depth assumes that the
632 632 // innermost loop has the lowest number. This is guaranteed by setting
633 633 // the loop number after the recursive calls for the successors above
634 634 // have returned.
635 635 if (cur->is_set(BlockBegin::linear_scan_loop_header_flag)) {
636 636 assert(cur->loop_index() == -1, "cannot set loop-index twice");
637 637 TRACE_LINEAR_SCAN(3, tty->print_cr("Block B%d is loop header of loop %d", cur->block_id(), _num_loops));
638 638
639 639 cur->set_loop_index(_num_loops);
640 640 _num_loops++;
641 641 }
642 642
643 643 TRACE_LINEAR_SCAN(3, tty->print_cr("Finished count_edges for block B%d", cur->block_id()));
644 644 }
645 645
646 646
647 647 void ComputeLinearScanOrder::mark_loops() {
648 648 TRACE_LINEAR_SCAN(3, tty->print_cr("----- marking loops"));
649 649
650 650 _loop_map = BitMap2D(_num_loops, _max_block_id);
651 651 _loop_map.clear();
652 652
653 653 for (int i = _loop_end_blocks.length() - 1; i >= 0; i--) {
654 654 BlockBegin* loop_end = _loop_end_blocks.at(i);
655 655 BlockBegin* loop_start = loop_end->sux_at(0);
656 656 int loop_idx = loop_start->loop_index();
657 657
658 658 TRACE_LINEAR_SCAN(3, tty->print_cr("Processing loop from B%d to B%d (loop %d):", loop_start->block_id(), loop_end->block_id(), loop_idx));
659 659 assert(loop_end->is_set(BlockBegin::linear_scan_loop_end_flag), "loop end flag must be set");
660 660 assert(loop_end->number_of_sux() == 1, "incorrect number of successors");
661 661 assert(loop_start->is_set(BlockBegin::linear_scan_loop_header_flag), "loop header flag must be set");
662 662 assert(loop_idx >= 0 && loop_idx < _num_loops, "loop index not set");
663 663 assert(_work_list.is_empty(), "work list must be empty before processing");
664 664
665 665 // add the end-block of the loop to the working list
666 666 _work_list.push(loop_end);
667 667 set_block_in_loop(loop_idx, loop_end);
668 668 do {
669 669 BlockBegin* cur = _work_list.pop();
670 670
671 671 TRACE_LINEAR_SCAN(3, tty->print_cr(" processing B%d", cur->block_id()));
672 672 assert(is_block_in_loop(loop_idx, cur), "bit in loop map must be set when block is in work list");
673 673
674 674 // recursive processing of all predecessors ends when start block of loop is reached
675 675 if (cur != loop_start && !cur->is_set(BlockBegin::osr_entry_flag)) {
676 676 for (int j = cur->number_of_preds() - 1; j >= 0; j--) {
677 677 BlockBegin* pred = cur->pred_at(j);
678 678
679 679 if (!is_block_in_loop(loop_idx, pred) /*&& !pred->is_set(BlockBeginosr_entry_flag)*/) {
680 680 // this predecessor has not been processed yet, so add it to work list
681 681 TRACE_LINEAR_SCAN(3, tty->print_cr(" pushing B%d", pred->block_id()));
682 682 _work_list.push(pred);
683 683 set_block_in_loop(loop_idx, pred);
684 684 }
685 685 }
686 686 }
687 687 } while (!_work_list.is_empty());
688 688 }
689 689 }
690 690
691 691
692 692 // check for non-natural loops (loops where the loop header does not dominate
693 693 // all other loop blocks = loops with mulitple entries).
694 694 // such loops are ignored
695 695 void ComputeLinearScanOrder::clear_non_natural_loops(BlockBegin* start_block) {
696 696 for (int i = _num_loops - 1; i >= 0; i--) {
697 697 if (is_block_in_loop(i, start_block)) {
698 698 // loop i contains the entry block of the method
699 699 // -> this is not a natural loop, so ignore it
700 700 TRACE_LINEAR_SCAN(2, tty->print_cr("Loop %d is non-natural, so it is ignored", i));
701 701
702 702 for (int block_id = _max_block_id - 1; block_id >= 0; block_id--) {
703 703 clear_block_in_loop(i, block_id);
704 704 }
705 705 _iterative_dominators = true;
706 706 }
707 707 }
708 708 }
709 709
710 710 void ComputeLinearScanOrder::assign_loop_depth(BlockBegin* start_block) {
711 711 TRACE_LINEAR_SCAN(3, "----- computing loop-depth and weight");
712 712 init_visited();
713 713
714 714 assert(_work_list.is_empty(), "work list must be empty before processing");
715 715 _work_list.append(start_block);
716 716
717 717 do {
718 718 BlockBegin* cur = _work_list.pop();
719 719
720 720 if (!is_visited(cur)) {
721 721 set_visited(cur);
722 722 TRACE_LINEAR_SCAN(4, tty->print_cr("Computing loop depth for block B%d", cur->block_id()));
723 723
724 724 // compute loop-depth and loop-index for the block
725 725 assert(cur->loop_depth() == 0, "cannot set loop-depth twice");
726 726 int i;
727 727 int loop_depth = 0;
728 728 int min_loop_idx = -1;
729 729 for (i = _num_loops - 1; i >= 0; i--) {
730 730 if (is_block_in_loop(i, cur)) {
731 731 loop_depth++;
732 732 min_loop_idx = i;
733 733 }
734 734 }
735 735 cur->set_loop_depth(loop_depth);
736 736 cur->set_loop_index(min_loop_idx);
737 737
738 738 // append all unvisited successors to work list
739 739 for (i = cur->number_of_sux() - 1; i >= 0; i--) {
740 740 _work_list.append(cur->sux_at(i));
741 741 }
742 742 for (i = cur->number_of_exception_handlers() - 1; i >= 0; i--) {
743 743 _work_list.append(cur->exception_handler_at(i));
744 744 }
745 745 }
746 746 } while (!_work_list.is_empty());
747 747 }
748 748
749 749
750 750 BlockBegin* ComputeLinearScanOrder::common_dominator(BlockBegin* a, BlockBegin* b) {
751 751 assert(a != NULL && b != NULL, "must have input blocks");
752 752
753 753 _dominator_blocks.clear();
754 754 while (a != NULL) {
755 755 _dominator_blocks.set_bit(a->block_id());
756 756 assert(a->dominator() != NULL || a == _linear_scan_order->at(0), "dominator must be initialized");
757 757 a = a->dominator();
758 758 }
759 759 while (b != NULL && !_dominator_blocks.at(b->block_id())) {
760 760 assert(b->dominator() != NULL || b == _linear_scan_order->at(0), "dominator must be initialized");
761 761 b = b->dominator();
762 762 }
763 763
764 764 assert(b != NULL, "could not find dominator");
765 765 return b;
766 766 }
767 767
768 768 void ComputeLinearScanOrder::compute_dominator(BlockBegin* cur, BlockBegin* parent) {
769 769 if (cur->dominator() == NULL) {
770 770 TRACE_LINEAR_SCAN(4, tty->print_cr("DOM: initializing dominator of B%d to B%d", cur->block_id(), parent->block_id()));
771 771 cur->set_dominator(parent);
772 772
773 773 } else if (!(cur->is_set(BlockBegin::linear_scan_loop_header_flag) && parent->is_set(BlockBegin::linear_scan_loop_end_flag))) {
774 774 TRACE_LINEAR_SCAN(4, tty->print_cr("DOM: computing dominator of B%d: common dominator of B%d and B%d is B%d", cur->block_id(), parent->block_id(), cur->dominator()->block_id(), common_dominator(cur->dominator(), parent)->block_id()));
775 775 assert(cur->number_of_preds() > 1, "");
776 776 cur->set_dominator(common_dominator(cur->dominator(), parent));
777 777 }
778 778 }
779 779
780 780
781 781 int ComputeLinearScanOrder::compute_weight(BlockBegin* cur) {
782 782 BlockBegin* single_sux = NULL;
783 783 if (cur->number_of_sux() == 1) {
784 784 single_sux = cur->sux_at(0);
785 785 }
786 786
787 787 // limit loop-depth to 15 bit (only for security reason, it will never be so big)
788 788 int weight = (cur->loop_depth() & 0x7FFF) << 16;
789 789
790 790 // general macro for short definition of weight flags
791 791 // the first instance of INC_WEIGHT_IF has the highest priority
792 792 int cur_bit = 15;
793 793 #define INC_WEIGHT_IF(condition) if ((condition)) { weight |= (1 << cur_bit); } cur_bit--;
794 794
795 795 // this is necessery for the (very rare) case that two successing blocks have
796 796 // the same loop depth, but a different loop index (can happen for endless loops
797 797 // with exception handlers)
798 798 INC_WEIGHT_IF(!cur->is_set(BlockBegin::linear_scan_loop_header_flag));
799 799
800 800 // loop end blocks (blocks that end with a backward branch) are added
801 801 // after all other blocks of the loop.
802 802 INC_WEIGHT_IF(!cur->is_set(BlockBegin::linear_scan_loop_end_flag));
803 803
804 804 // critical edge split blocks are prefered because than they have a bigger
805 805 // proability to be completely empty
806 806 INC_WEIGHT_IF(cur->is_set(BlockBegin::critical_edge_split_flag));
807 807
808 808 // exceptions should not be thrown in normal control flow, so these blocks
809 809 // are added as late as possible
810 810 INC_WEIGHT_IF(cur->end()->as_Throw() == NULL && (single_sux == NULL || single_sux->end()->as_Throw() == NULL));
811 811 INC_WEIGHT_IF(cur->end()->as_Return() == NULL && (single_sux == NULL || single_sux->end()->as_Return() == NULL));
812 812
813 813 // exceptions handlers are added as late as possible
814 814 INC_WEIGHT_IF(!cur->is_set(BlockBegin::exception_entry_flag));
815 815
816 816 // guarantee that weight is > 0
817 817 weight |= 1;
818 818
819 819 #undef INC_WEIGHT_IF
820 820 assert(cur_bit >= 0, "too many flags");
821 821 assert(weight > 0, "weight cannot become negative");
822 822
823 823 return weight;
824 824 }
825 825
826 826 bool ComputeLinearScanOrder::ready_for_processing(BlockBegin* cur) {
827 827 // Discount the edge just traveled.
828 828 // When the number drops to zero, all forward branches were processed
829 829 if (dec_forward_branches(cur) != 0) {
830 830 return false;
831 831 }
832 832
833 833 assert(_linear_scan_order->index_of(cur) == -1, "block already processed (block can be ready only once)");
834 834 assert(_work_list.index_of(cur) == -1, "block already in work-list (block can be ready only once)");
835 835 return true;
836 836 }
837 837
838 838 void ComputeLinearScanOrder::sort_into_work_list(BlockBegin* cur) {
839 839 assert(_work_list.index_of(cur) == -1, "block already in work list");
840 840
841 841 int cur_weight = compute_weight(cur);
842 842
843 843 // the linear_scan_number is used to cache the weight of a block
844 844 cur->set_linear_scan_number(cur_weight);
845 845
846 846 #ifndef PRODUCT
847 847 if (StressLinearScan) {
848 848 _work_list.insert_before(0, cur);
849 849 return;
850 850 }
851 851 #endif
852 852
853 853 _work_list.append(NULL); // provide space for new element
854 854
855 855 int insert_idx = _work_list.length() - 1;
856 856 while (insert_idx > 0 && _work_list.at(insert_idx - 1)->linear_scan_number() > cur_weight) {
857 857 _work_list.at_put(insert_idx, _work_list.at(insert_idx - 1));
858 858 insert_idx--;
859 859 }
860 860 _work_list.at_put(insert_idx, cur);
861 861
862 862 TRACE_LINEAR_SCAN(3, tty->print_cr("Sorted B%d into worklist. new worklist:", cur->block_id()));
863 863 TRACE_LINEAR_SCAN(3, for (int i = 0; i < _work_list.length(); i++) tty->print_cr("%8d B%2d weight:%6x", i, _work_list.at(i)->block_id(), _work_list.at(i)->linear_scan_number()));
864 864
865 865 #ifdef ASSERT
866 866 for (int i = 0; i < _work_list.length(); i++) {
867 867 assert(_work_list.at(i)->linear_scan_number() > 0, "weight not set");
868 868 assert(i == 0 || _work_list.at(i - 1)->linear_scan_number() <= _work_list.at(i)->linear_scan_number(), "incorrect order in worklist");
869 869 }
870 870 #endif
871 871 }
872 872
873 873 void ComputeLinearScanOrder::append_block(BlockBegin* cur) {
874 874 TRACE_LINEAR_SCAN(3, tty->print_cr("appending block B%d (weight 0x%6x) to linear-scan order", cur->block_id(), cur->linear_scan_number()));
875 875 assert(_linear_scan_order->index_of(cur) == -1, "cannot add the same block twice");
876 876
877 877 // currently, the linear scan order and code emit order are equal.
878 878 // therefore the linear_scan_number and the weight of a block must also
879 879 // be equal.
880 880 cur->set_linear_scan_number(_linear_scan_order->length());
881 881 _linear_scan_order->append(cur);
882 882 }
883 883
884 884 void ComputeLinearScanOrder::compute_order(BlockBegin* start_block) {
885 885 TRACE_LINEAR_SCAN(3, "----- computing final block order");
886 886
887 887 // the start block is always the first block in the linear scan order
888 888 _linear_scan_order = new BlockList(_num_blocks);
889 889 append_block(start_block);
890 890
891 891 assert(start_block->end()->as_Base() != NULL, "start block must end with Base-instruction");
892 892 BlockBegin* std_entry = ((Base*)start_block->end())->std_entry();
893 893 BlockBegin* osr_entry = ((Base*)start_block->end())->osr_entry();
894 894
895 895 BlockBegin* sux_of_osr_entry = NULL;
896 896 if (osr_entry != NULL) {
897 897 // special handling for osr entry:
898 898 // ignore the edge between the osr entry and its successor for processing
899 899 // the osr entry block is added manually below
900 900 assert(osr_entry->number_of_sux() == 1, "osr entry must have exactly one successor");
901 901 assert(osr_entry->sux_at(0)->number_of_preds() >= 2, "sucessor of osr entry must have two predecessors (otherwise it is not present in normal control flow");
902 902
903 903 sux_of_osr_entry = osr_entry->sux_at(0);
904 904 dec_forward_branches(sux_of_osr_entry);
905 905
906 906 compute_dominator(osr_entry, start_block);
907 907 _iterative_dominators = true;
908 908 }
909 909 compute_dominator(std_entry, start_block);
910 910
911 911 // start processing with standard entry block
912 912 assert(_work_list.is_empty(), "list must be empty before processing");
913 913
914 914 if (ready_for_processing(std_entry)) {
915 915 sort_into_work_list(std_entry);
916 916 } else {
917 917 assert(false, "the std_entry must be ready for processing (otherwise, the method has no start block)");
918 918 }
919 919
920 920 do {
921 921 BlockBegin* cur = _work_list.pop();
922 922
923 923 if (cur == sux_of_osr_entry) {
924 924 // the osr entry block is ignored in normal processing, it is never added to the
925 925 // work list. Instead, it is added as late as possible manually here.
926 926 append_block(osr_entry);
927 927 compute_dominator(cur, osr_entry);
928 928 }
929 929 append_block(cur);
930 930
931 931 int i;
932 932 int num_sux = cur->number_of_sux();
933 933 // changed loop order to get "intuitive" order of if- and else-blocks
934 934 for (i = 0; i < num_sux; i++) {
935 935 BlockBegin* sux = cur->sux_at(i);
936 936 compute_dominator(sux, cur);
937 937 if (ready_for_processing(sux)) {
938 938 sort_into_work_list(sux);
939 939 }
940 940 }
941 941 num_sux = cur->number_of_exception_handlers();
942 942 for (i = 0; i < num_sux; i++) {
943 943 BlockBegin* sux = cur->exception_handler_at(i);
944 944 compute_dominator(sux, cur);
945 945 if (ready_for_processing(sux)) {
946 946 sort_into_work_list(sux);
947 947 }
948 948 }
949 949 } while (_work_list.length() > 0);
950 950 }
951 951
952 952
953 953 bool ComputeLinearScanOrder::compute_dominators_iter() {
954 954 bool changed = false;
955 955 int num_blocks = _linear_scan_order->length();
956 956
957 957 assert(_linear_scan_order->at(0)->dominator() == NULL, "must not have dominator");
958 958 assert(_linear_scan_order->at(0)->number_of_preds() == 0, "must not have predecessors");
959 959 for (int i = 1; i < num_blocks; i++) {
960 960 BlockBegin* block = _linear_scan_order->at(i);
961 961
962 962 BlockBegin* dominator = block->pred_at(0);
963 963 int num_preds = block->number_of_preds();
964 964 for (int i = 1; i < num_preds; i++) {
965 965 dominator = common_dominator(dominator, block->pred_at(i));
966 966 }
967 967
968 968 if (dominator != block->dominator()) {
969 969 TRACE_LINEAR_SCAN(4, tty->print_cr("DOM: updating dominator of B%d from B%d to B%d", block->block_id(), block->dominator()->block_id(), dominator->block_id()));
970 970
971 971 block->set_dominator(dominator);
972 972 changed = true;
973 973 }
974 974 }
975 975 return changed;
976 976 }
977 977
978 978 void ComputeLinearScanOrder::compute_dominators() {
979 979 TRACE_LINEAR_SCAN(3, tty->print_cr("----- computing dominators (iterative computation reqired: %d)", _iterative_dominators));
980 980
981 981 // iterative computation of dominators is only required for methods with non-natural loops
982 982 // and OSR-methods. For all other methods, the dominators computed when generating the
983 983 // linear scan block order are correct.
984 984 if (_iterative_dominators) {
985 985 do {
986 986 TRACE_LINEAR_SCAN(1, tty->print_cr("DOM: next iteration of fix-point calculation"));
987 987 } while (compute_dominators_iter());
988 988 }
989 989
990 990 // check that dominators are correct
991 991 assert(!compute_dominators_iter(), "fix point not reached");
992 992 }
993 993
994 994
995 995 #ifndef PRODUCT
996 996 void ComputeLinearScanOrder::print_blocks() {
997 997 if (TraceLinearScanLevel >= 2) {
998 998 tty->print_cr("----- loop information:");
999 999 for (int block_idx = 0; block_idx < _linear_scan_order->length(); block_idx++) {
1000 1000 BlockBegin* cur = _linear_scan_order->at(block_idx);
1001 1001
1002 1002 tty->print("%4d: B%2d: ", cur->linear_scan_number(), cur->block_id());
1003 1003 for (int loop_idx = 0; loop_idx < _num_loops; loop_idx++) {
1004 1004 tty->print ("%d ", is_block_in_loop(loop_idx, cur));
1005 1005 }
1006 1006 tty->print_cr(" -> loop_index: %2d, loop_depth: %2d", cur->loop_index(), cur->loop_depth());
1007 1007 }
1008 1008 }
1009 1009
1010 1010 if (TraceLinearScanLevel >= 1) {
1011 1011 tty->print_cr("----- linear-scan block order:");
1012 1012 for (int block_idx = 0; block_idx < _linear_scan_order->length(); block_idx++) {
1013 1013 BlockBegin* cur = _linear_scan_order->at(block_idx);
1014 1014 tty->print("%4d: B%2d loop: %2d depth: %2d", cur->linear_scan_number(), cur->block_id(), cur->loop_index(), cur->loop_depth());
1015 1015
1016 1016 tty->print(cur->is_set(BlockBegin::exception_entry_flag) ? " ex" : " ");
1017 1017 tty->print(cur->is_set(BlockBegin::critical_edge_split_flag) ? " ce" : " ");
1018 1018 tty->print(cur->is_set(BlockBegin::linear_scan_loop_header_flag) ? " lh" : " ");
1019 1019 tty->print(cur->is_set(BlockBegin::linear_scan_loop_end_flag) ? " le" : " ");
1020 1020
1021 1021 if (cur->dominator() != NULL) {
1022 1022 tty->print(" dom: B%d ", cur->dominator()->block_id());
1023 1023 } else {
1024 1024 tty->print(" dom: NULL ");
1025 1025 }
1026 1026
1027 1027 if (cur->number_of_preds() > 0) {
1028 1028 tty->print(" preds: ");
1029 1029 for (int j = 0; j < cur->number_of_preds(); j++) {
1030 1030 BlockBegin* pred = cur->pred_at(j);
1031 1031 tty->print("B%d ", pred->block_id());
1032 1032 }
1033 1033 }
1034 1034 if (cur->number_of_sux() > 0) {
1035 1035 tty->print(" sux: ");
1036 1036 for (int j = 0; j < cur->number_of_sux(); j++) {
1037 1037 BlockBegin* sux = cur->sux_at(j);
1038 1038 tty->print("B%d ", sux->block_id());
1039 1039 }
1040 1040 }
1041 1041 if (cur->number_of_exception_handlers() > 0) {
1042 1042 tty->print(" ex: ");
1043 1043 for (int j = 0; j < cur->number_of_exception_handlers(); j++) {
1044 1044 BlockBegin* ex = cur->exception_handler_at(j);
1045 1045 tty->print("B%d ", ex->block_id());
1046 1046 }
1047 1047 }
1048 1048 tty->cr();
1049 1049 }
1050 1050 }
1051 1051 }
1052 1052 #endif
1053 1053
1054 1054 #ifdef ASSERT
1055 1055 void ComputeLinearScanOrder::verify() {
1056 1056 assert(_linear_scan_order->length() == _num_blocks, "wrong number of blocks in list");
1057 1057
1058 1058 if (StressLinearScan) {
1059 1059 // blocks are scrambled when StressLinearScan is used
1060 1060 return;
1061 1061 }
1062 1062
1063 1063 // check that all successors of a block have a higher linear-scan-number
1064 1064 // and that all predecessors of a block have a lower linear-scan-number
1065 1065 // (only backward branches of loops are ignored)
1066 1066 int i;
1067 1067 for (i = 0; i < _linear_scan_order->length(); i++) {
1068 1068 BlockBegin* cur = _linear_scan_order->at(i);
1069 1069
1070 1070 assert(cur->linear_scan_number() == i, "incorrect linear_scan_number");
1071 1071 assert(cur->linear_scan_number() >= 0 && cur->linear_scan_number() == _linear_scan_order->index_of(cur), "incorrect linear_scan_number");
1072 1072
1073 1073 int j;
1074 1074 for (j = cur->number_of_sux() - 1; j >= 0; j--) {
1075 1075 BlockBegin* sux = cur->sux_at(j);
1076 1076
1077 1077 assert(sux->linear_scan_number() >= 0 && sux->linear_scan_number() == _linear_scan_order->index_of(sux), "incorrect linear_scan_number");
1078 1078 if (!cur->is_set(BlockBegin::linear_scan_loop_end_flag)) {
1079 1079 assert(cur->linear_scan_number() < sux->linear_scan_number(), "invalid order");
1080 1080 }
1081 1081 if (cur->loop_depth() == sux->loop_depth()) {
1082 1082 assert(cur->loop_index() == sux->loop_index() || sux->is_set(BlockBegin::linear_scan_loop_header_flag), "successing blocks with same loop depth must have same loop index");
1083 1083 }
1084 1084 }
1085 1085
1086 1086 for (j = cur->number_of_preds() - 1; j >= 0; j--) {
1087 1087 BlockBegin* pred = cur->pred_at(j);
1088 1088
1089 1089 assert(pred->linear_scan_number() >= 0 && pred->linear_scan_number() == _linear_scan_order->index_of(pred), "incorrect linear_scan_number");
1090 1090 if (!cur->is_set(BlockBegin::linear_scan_loop_header_flag)) {
1091 1091 assert(cur->linear_scan_number() > pred->linear_scan_number(), "invalid order");
1092 1092 }
1093 1093 if (cur->loop_depth() == pred->loop_depth()) {
1094 1094 assert(cur->loop_index() == pred->loop_index() || cur->is_set(BlockBegin::linear_scan_loop_header_flag), "successing blocks with same loop depth must have same loop index");
1095 1095 }
1096 1096
1097 1097 assert(cur->dominator()->linear_scan_number() <= cur->pred_at(j)->linear_scan_number(), "dominator must be before predecessors");
1098 1098 }
1099 1099
1100 1100 // check dominator
1101 1101 if (i == 0) {
1102 1102 assert(cur->dominator() == NULL, "first block has no dominator");
1103 1103 } else {
1104 1104 assert(cur->dominator() != NULL, "all but first block must have dominator");
1105 1105 }
1106 1106 assert(cur->number_of_preds() != 1 || cur->dominator() == cur->pred_at(0), "Single predecessor must also be dominator");
1107 1107 }
1108 1108
1109 1109 // check that all loops are continuous
1110 1110 for (int loop_idx = 0; loop_idx < _num_loops; loop_idx++) {
1111 1111 int block_idx = 0;
1112 1112 assert(!is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx)), "the first block must not be present in any loop");
1113 1113
1114 1114 // skip blocks before the loop
1115 1115 while (block_idx < _num_blocks && !is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx))) {
1116 1116 block_idx++;
1117 1117 }
1118 1118 // skip blocks of loop
1119 1119 while (block_idx < _num_blocks && is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx))) {
1120 1120 block_idx++;
1121 1121 }
1122 1122 // after the first non-loop block, there must not be another loop-block
1123 1123 while (block_idx < _num_blocks) {
1124 1124 assert(!is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx)), "loop not continuous in linear-scan order");
1125 1125 block_idx++;
1126 1126 }
1127 1127 }
1128 1128 }
1129 1129 #endif
1130 1130
1131 1131
1132 1132 void IR::compute_code() {
1133 1133 assert(is_valid(), "IR must be valid");
1134 1134
1135 1135 ComputeLinearScanOrder compute_order(start());
1136 1136 _num_loops = compute_order.num_loops();
1137 1137 _code = compute_order.linear_scan_order();
1138 1138 }
1139 1139
1140 1140
1141 1141 void IR::compute_use_counts() {
1142 1142 // make sure all values coming out of this block get evaluated.
1143 1143 int num_blocks = _code->length();
1144 1144 for (int i = 0; i < num_blocks; i++) {
1145 1145 _code->at(i)->end()->state()->pin_stack_for_linear_scan();
1146 1146 }
1147 1147
1148 1148 // compute use counts
1149 1149 UseCountComputer::compute(_code);
1150 1150 }
1151 1151
1152 1152
1153 1153 void IR::iterate_preorder(BlockClosure* closure) {
1154 1154 assert(is_valid(), "IR must be valid");
1155 1155 start()->iterate_preorder(closure);
1156 1156 }
1157 1157
1158 1158
1159 1159 void IR::iterate_postorder(BlockClosure* closure) {
1160 1160 assert(is_valid(), "IR must be valid");
1161 1161 start()->iterate_postorder(closure);
1162 1162 }
1163 1163
1164 1164 void IR::iterate_linear_scan_order(BlockClosure* closure) {
1165 1165 linear_scan_order()->iterate_forward(closure);
1166 1166 }
1167 1167
1168 1168
1169 1169 #ifndef PRODUCT
1170 1170 class BlockPrinter: public BlockClosure {
1171 1171 private:
1172 1172 InstructionPrinter* _ip;
1173 1173 bool _cfg_only;
1174 1174 bool _live_only;
1175 1175
1176 1176 public:
1177 1177 BlockPrinter(InstructionPrinter* ip, bool cfg_only, bool live_only = false) {
1178 1178 _ip = ip;
1179 1179 _cfg_only = cfg_only;
1180 1180 _live_only = live_only;
1181 1181 }
1182 1182
1183 1183 virtual void block_do(BlockBegin* block) {
1184 1184 if (_cfg_only) {
1185 1185 _ip->print_instr(block); tty->cr();
1186 1186 } else {
1187 1187 block->print_block(*_ip, _live_only);
1188 1188 }
1189 1189 }
1190 1190 };
1191 1191
1192 1192
1193 1193 void IR::print(BlockBegin* start, bool cfg_only, bool live_only) {
1194 1194 ttyLocker ttyl;
1195 1195 InstructionPrinter ip(!cfg_only);
1196 1196 BlockPrinter bp(&ip, cfg_only, live_only);
1197 1197 start->iterate_preorder(&bp);
1198 1198 tty->cr();
1199 1199 }
1200 1200
1201 1201 void IR::print(bool cfg_only, bool live_only) {
1202 1202 if (is_valid()) {
1203 1203 print(start(), cfg_only, live_only);
1204 1204 } else {
1205 1205 tty->print_cr("invalid IR");
1206 1206 }
1207 1207 }
1208 1208
1209 1209
1210 1210 define_array(BlockListArray, BlockList*)
1211 1211 define_stack(BlockListList, BlockListArray)
1212 1212
1213 1213 class PredecessorValidator : public BlockClosure {
1214 1214 private:
1215 1215 BlockListList* _predecessors;
1216 1216 BlockList* _blocks;
1217 1217
1218 1218 static int cmp(BlockBegin** a, BlockBegin** b) {
1219 1219 return (*a)->block_id() - (*b)->block_id();
1220 1220 }
1221 1221
1222 1222 public:
1223 1223 PredecessorValidator(IR* hir) {
1224 1224 ResourceMark rm;
1225 1225 _predecessors = new BlockListList(BlockBegin::number_of_blocks(), NULL);
1226 1226 _blocks = new BlockList();
1227 1227
1228 1228 int i;
1229 1229 hir->start()->iterate_preorder(this);
1230 1230 if (hir->code() != NULL) {
1231 1231 assert(hir->code()->length() == _blocks->length(), "must match");
1232 1232 for (i = 0; i < _blocks->length(); i++) {
1233 1233 assert(hir->code()->contains(_blocks->at(i)), "should be in both lists");
1234 1234 }
1235 1235 }
1236 1236
1237 1237 for (i = 0; i < _blocks->length(); i++) {
1238 1238 BlockBegin* block = _blocks->at(i);
1239 1239 BlockList* preds = _predecessors->at(block->block_id());
1240 1240 if (preds == NULL) {
1241 1241 assert(block->number_of_preds() == 0, "should be the same");
1242 1242 continue;
1243 1243 }
1244 1244
1245 1245 // clone the pred list so we can mutate it
1246 1246 BlockList* pred_copy = new BlockList();
1247 1247 int j;
1248 1248 for (j = 0; j < block->number_of_preds(); j++) {
1249 1249 pred_copy->append(block->pred_at(j));
1250 1250 }
1251 1251 // sort them in the same order
1252 1252 preds->sort(cmp);
1253 1253 pred_copy->sort(cmp);
1254 1254 int length = MIN2(preds->length(), block->number_of_preds());
1255 1255 for (j = 0; j < block->number_of_preds(); j++) {
1256 1256 assert(preds->at(j) == pred_copy->at(j), "must match");
1257 1257 }
1258 1258
1259 1259 assert(preds->length() == block->number_of_preds(), "should be the same");
1260 1260 }
1261 1261 }
1262 1262
1263 1263 virtual void block_do(BlockBegin* block) {
1264 1264 _blocks->append(block);
1265 1265 BlockEnd* be = block->end();
1266 1266 int n = be->number_of_sux();
1267 1267 int i;
1268 1268 for (i = 0; i < n; i++) {
1269 1269 BlockBegin* sux = be->sux_at(i);
1270 1270 assert(!sux->is_set(BlockBegin::exception_entry_flag), "must not be xhandler");
1271 1271
1272 1272 BlockList* preds = _predecessors->at_grow(sux->block_id(), NULL);
1273 1273 if (preds == NULL) {
1274 1274 preds = new BlockList();
1275 1275 _predecessors->at_put(sux->block_id(), preds);
1276 1276 }
1277 1277 preds->append(block);
1278 1278 }
1279 1279
1280 1280 n = block->number_of_exception_handlers();
1281 1281 for (i = 0; i < n; i++) {
1282 1282 BlockBegin* sux = block->exception_handler_at(i);
1283 1283 assert(sux->is_set(BlockBegin::exception_entry_flag), "must be xhandler");
1284 1284
1285 1285 BlockList* preds = _predecessors->at_grow(sux->block_id(), NULL);
1286 1286 if (preds == NULL) {
1287 1287 preds = new BlockList();
1288 1288 _predecessors->at_put(sux->block_id(), preds);
1289 1289 }
1290 1290 preds->append(block);
1291 1291 }
1292 1292 }
1293 1293 };
1294 1294
1295 1295 void IR::verify() {
1296 1296 #ifdef ASSERT
1297 1297 PredecessorValidator pv(this);
1298 1298 #endif
1299 1299 }
1300 1300
1301 1301 #endif // PRODUCT
1302 1302
1303 1303 void SubstitutionResolver::substitute(Value* v) {
1304 1304 Value v0 = *v;
1305 1305 if (v0) {
1306 1306 Value vs = v0->subst();
1307 1307 if (vs != v0) {
1308 1308 *v = v0->subst();
1309 1309 }
1310 1310 }
1311 1311 }
1312 1312
1313 1313 #ifdef ASSERT
1314 1314 void check_substitute(Value* v) {
1315 1315 Value v0 = *v;
1316 1316 if (v0) {
1317 1317 Value vs = v0->subst();
1318 1318 assert(vs == v0, "missed substitution");
1319 1319 }
1320 1320 }
1321 1321 #endif
1322 1322
1323 1323
1324 1324 void SubstitutionResolver::block_do(BlockBegin* block) {
1325 1325 Instruction* last = NULL;
1326 1326 for (Instruction* n = block; n != NULL;) {
1327 1327 n->values_do(substitute);
1328 1328 // need to remove this instruction from the instruction stream
1329 1329 if (n->subst() != n) {
1330 1330 assert(last != NULL, "must have last");
1331 1331 last->set_next(n->next(), n->next()->bci());
1332 1332 } else {
1333 1333 last = n;
1334 1334 }
1335 1335 n = last->next();
1336 1336 }
1337 1337
1338 1338 #ifdef ASSERT
1339 1339 if (block->state()) block->state()->values_do(check_substitute);
1340 1340 block->block_values_do(check_substitute);
1341 1341 if (block->end() && block->end()->state()) block->end()->state()->values_do(check_substitute);
1342 1342 #endif
1343 1343 }
|
↓ open down ↓ |
1068 lines elided |
↑ open up ↑ |
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX