Mercurial > hg > truffle
annotate src/share/vm/c1/c1_IR.cpp @ 14680:2dfa56e10640
8027124: [TESTBUG] NonTieredLevelsTest: java.lang.RuntimeException: private TestCase$Helper(java.lang.Object) must be osr_compiled
Reviewed-by: kvn, roland
author | iignatyev |
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date | Thu, 06 Mar 2014 12:47:45 +0400 |
parents | 3edd4a71588b |
children | b51e29501f30 |
rev | line source |
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0 | 1 /* |
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2 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved. |
0 | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
4 * | |
5 * This code is free software; you can redistribute it and/or modify it | |
6 * under the terms of the GNU General Public License version 2 only, as | |
7 * published by the Free Software Foundation. | |
8 * | |
9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
12 * version 2 for more details (a copy is included in the LICENSE file that | |
13 * accompanied this code). | |
14 * | |
15 * You should have received a copy of the GNU General Public License version | |
16 * 2 along with this work; if not, write to the Free Software Foundation, | |
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 * | |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 25 #include "precompiled.hpp" |
26 #include "c1/c1_Compilation.hpp" | |
27 #include "c1/c1_FrameMap.hpp" | |
28 #include "c1/c1_GraphBuilder.hpp" | |
29 #include "c1/c1_IR.hpp" | |
30 #include "c1/c1_InstructionPrinter.hpp" | |
31 #include "c1/c1_Optimizer.hpp" | |
32 #include "utilities/bitMap.inline.hpp" | |
0 | 33 |
34 | |
35 // Implementation of XHandlers | |
36 // | |
37 // Note: This code could eventually go away if we are | |
38 // just using the ciExceptionHandlerStream. | |
39 | |
40 XHandlers::XHandlers(ciMethod* method) : _list(method->exception_table_length()) { | |
41 ciExceptionHandlerStream s(method); | |
42 while (!s.is_done()) { | |
43 _list.append(new XHandler(s.handler())); | |
44 s.next(); | |
45 } | |
46 assert(s.count() == method->exception_table_length(), "exception table lengths inconsistent"); | |
47 } | |
48 | |
49 // deep copy of all XHandler contained in list | |
50 XHandlers::XHandlers(XHandlers* other) : | |
51 _list(other->length()) | |
52 { | |
53 for (int i = 0; i < other->length(); i++) { | |
54 _list.append(new XHandler(other->handler_at(i))); | |
55 } | |
56 } | |
57 | |
58 // Returns whether a particular exception type can be caught. Also | |
59 // returns true if klass is unloaded or any exception handler | |
60 // classes are unloaded. type_is_exact indicates whether the throw | |
61 // is known to be exactly that class or it might throw a subtype. | |
62 bool XHandlers::could_catch(ciInstanceKlass* klass, bool type_is_exact) const { | |
63 // the type is unknown so be conservative | |
64 if (!klass->is_loaded()) { | |
65 return true; | |
66 } | |
67 | |
68 for (int i = 0; i < length(); i++) { | |
69 XHandler* handler = handler_at(i); | |
70 if (handler->is_catch_all()) { | |
71 // catch of ANY | |
72 return true; | |
73 } | |
74 ciInstanceKlass* handler_klass = handler->catch_klass(); | |
75 // if it's unknown it might be catchable | |
76 if (!handler_klass->is_loaded()) { | |
77 return true; | |
78 } | |
79 // if the throw type is definitely a subtype of the catch type | |
80 // then it can be caught. | |
81 if (klass->is_subtype_of(handler_klass)) { | |
82 return true; | |
83 } | |
84 if (!type_is_exact) { | |
85 // If the type isn't exactly known then it can also be caught by | |
86 // catch statements where the inexact type is a subtype of the | |
87 // catch type. | |
88 // given: foo extends bar extends Exception | |
89 // throw bar can be caught by catch foo, catch bar, and catch | |
90 // Exception, however it can't be caught by any handlers without | |
91 // bar in its type hierarchy. | |
92 if (handler_klass->is_subtype_of(klass)) { | |
93 return true; | |
94 } | |
95 } | |
96 } | |
97 | |
98 return false; | |
99 } | |
100 | |
101 | |
102 bool XHandlers::equals(XHandlers* others) const { | |
103 if (others == NULL) return false; | |
104 if (length() != others->length()) return false; | |
105 | |
106 for (int i = 0; i < length(); i++) { | |
107 if (!handler_at(i)->equals(others->handler_at(i))) return false; | |
108 } | |
109 return true; | |
110 } | |
111 | |
112 bool XHandler::equals(XHandler* other) const { | |
113 assert(entry_pco() != -1 && other->entry_pco() != -1, "must have entry_pco"); | |
114 | |
115 if (entry_pco() != other->entry_pco()) return false; | |
116 if (scope_count() != other->scope_count()) return false; | |
117 if (_desc != other->_desc) return false; | |
118 | |
119 assert(entry_block() == other->entry_block(), "entry_block must be equal when entry_pco is equal"); | |
120 return true; | |
121 } | |
122 | |
123 | |
124 // Implementation of IRScope | |
125 BlockBegin* IRScope::build_graph(Compilation* compilation, int osr_bci) { | |
126 GraphBuilder gm(compilation, this); | |
127 NOT_PRODUCT(if (PrintValueNumbering && Verbose) gm.print_stats()); | |
128 if (compilation->bailed_out()) return NULL; | |
129 return gm.start(); | |
130 } | |
131 | |
132 | |
133 IRScope::IRScope(Compilation* compilation, IRScope* caller, int caller_bci, ciMethod* method, int osr_bci, bool create_graph) | |
134 : _callees(2) | |
135 , _compilation(compilation) | |
136 , _requires_phi_function(method->max_locals()) | |
137 { | |
138 _caller = caller; | |
139 _level = caller == NULL ? 0 : caller->level() + 1; | |
140 _method = method; | |
141 _xhandlers = new XHandlers(method); | |
142 _number_of_locks = 0; | |
143 _monitor_pairing_ok = method->has_balanced_monitors(); | |
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144 _wrote_final = false; |
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145 _wrote_fields = false; |
0 | 146 _start = NULL; |
147 | |
148 if (osr_bci == -1) { | |
149 _requires_phi_function.clear(); | |
150 } else { | |
151 // selective creation of phi functions is not possibel in osr-methods | |
152 _requires_phi_function.set_range(0, method->max_locals()); | |
153 } | |
154 | |
155 assert(method->holder()->is_loaded() , "method holder must be loaded"); | |
156 | |
157 // build graph if monitor pairing is ok | |
158 if (create_graph && monitor_pairing_ok()) _start = build_graph(compilation, osr_bci); | |
159 } | |
160 | |
161 | |
162 int IRScope::max_stack() const { | |
163 int my_max = method()->max_stack(); | |
164 int callee_max = 0; | |
165 for (int i = 0; i < number_of_callees(); i++) { | |
166 callee_max = MAX2(callee_max, callee_no(i)->max_stack()); | |
167 } | |
168 return my_max + callee_max; | |
169 } | |
170 | |
171 | |
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172 bool IRScopeDebugInfo::should_reexecute() { |
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173 ciMethod* cur_method = scope()->method(); |
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174 int cur_bci = bci(); |
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175 if (cur_method != NULL && cur_bci != SynchronizationEntryBCI) { |
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176 Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci); |
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177 return Interpreter::bytecode_should_reexecute(code); |
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178 } else |
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179 return false; |
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180 } |
0 | 181 |
182 | |
183 // Implementation of CodeEmitInfo | |
184 | |
185 // Stack must be NON-null | |
8860 | 186 CodeEmitInfo::CodeEmitInfo(ValueStack* stack, XHandlers* exception_handlers, bool deoptimize_on_exception) |
0 | 187 : _scope(stack->scope()) |
188 , _scope_debug_info(NULL) | |
189 , _oop_map(NULL) | |
190 , _stack(stack) | |
191 , _exception_handlers(exception_handlers) | |
8860 | 192 , _is_method_handle_invoke(false) |
193 , _deoptimize_on_exception(deoptimize_on_exception) { | |
0 | 194 assert(_stack != NULL, "must be non null"); |
195 } | |
196 | |
197 | |
1819 | 198 CodeEmitInfo::CodeEmitInfo(CodeEmitInfo* info, ValueStack* stack) |
0 | 199 : _scope(info->_scope) |
200 , _exception_handlers(NULL) | |
201 , _scope_debug_info(NULL) | |
1564 | 202 , _oop_map(NULL) |
1819 | 203 , _stack(stack == NULL ? info->_stack : stack) |
8860 | 204 , _is_method_handle_invoke(info->_is_method_handle_invoke) |
205 , _deoptimize_on_exception(info->_deoptimize_on_exception) { | |
0 | 206 |
207 // deep copy of exception handlers | |
208 if (info->_exception_handlers != NULL) { | |
209 _exception_handlers = new XHandlers(info->_exception_handlers); | |
210 } | |
211 } | |
212 | |
213 | |
1564 | 214 void CodeEmitInfo::record_debug_info(DebugInformationRecorder* recorder, int pc_offset) { |
0 | 215 // record the safepoint before recording the debug info for enclosing scopes |
216 recorder->add_safepoint(pc_offset, _oop_map->deep_copy()); | |
1564 | 217 _scope_debug_info->record_debug_info(recorder, pc_offset, true/*topmost*/, _is_method_handle_invoke); |
0 | 218 recorder->end_safepoint(pc_offset); |
219 } | |
220 | |
221 | |
222 void CodeEmitInfo::add_register_oop(LIR_Opr opr) { | |
223 assert(_oop_map != NULL, "oop map must already exist"); | |
224 assert(opr->is_single_cpu(), "should not call otherwise"); | |
225 | |
226 VMReg name = frame_map()->regname(opr); | |
227 _oop_map->set_oop(name); | |
228 } | |
229 | |
230 | |
231 | |
232 | |
233 // Implementation of IR | |
234 | |
235 IR::IR(Compilation* compilation, ciMethod* method, int osr_bci) : | |
236 _locals_size(in_WordSize(-1)) | |
237 , _num_loops(0) { | |
238 // setup IR fields | |
239 _compilation = compilation; | |
240 _top_scope = new IRScope(compilation, NULL, -1, method, osr_bci, true); | |
241 _code = NULL; | |
242 } | |
243 | |
244 | |
8860 | 245 void IR::optimize_blocks() { |
0 | 246 Optimizer opt(this); |
1783 | 247 if (!compilation()->profile_branches()) { |
248 if (DoCEE) { | |
249 opt.eliminate_conditional_expressions(); | |
0 | 250 #ifndef PRODUCT |
1783 | 251 if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after CEE"); print(true); } |
252 if (PrintIR || PrintIR1 ) { tty->print_cr("IR after CEE"); print(false); } | |
0 | 253 #endif |
1783 | 254 } |
255 if (EliminateBlocks) { | |
256 opt.eliminate_blocks(); | |
0 | 257 #ifndef PRODUCT |
1783 | 258 if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after block elimination"); print(true); } |
259 if (PrintIR || PrintIR1 ) { tty->print_cr("IR after block elimination"); print(false); } | |
0 | 260 #endif |
1783 | 261 } |
0 | 262 } |
8860 | 263 } |
264 | |
265 void IR::eliminate_null_checks() { | |
266 Optimizer opt(this); | |
0 | 267 if (EliminateNullChecks) { |
268 opt.eliminate_null_checks(); | |
269 #ifndef PRODUCT | |
270 if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after null check elimination"); print(true); } | |
271 if (PrintIR || PrintIR1 ) { tty->print_cr("IR after null check elimination"); print(false); } | |
272 #endif | |
273 } | |
274 } | |
275 | |
276 | |
277 static int sort_pairs(BlockPair** a, BlockPair** b) { | |
278 if ((*a)->from() == (*b)->from()) { | |
279 return (*a)->to()->block_id() - (*b)->to()->block_id(); | |
280 } else { | |
281 return (*a)->from()->block_id() - (*b)->from()->block_id(); | |
282 } | |
283 } | |
284 | |
285 | |
286 class CriticalEdgeFinder: public BlockClosure { | |
287 BlockPairList blocks; | |
288 IR* _ir; | |
289 | |
290 public: | |
291 CriticalEdgeFinder(IR* ir): _ir(ir) {} | |
292 void block_do(BlockBegin* bb) { | |
293 BlockEnd* be = bb->end(); | |
294 int nos = be->number_of_sux(); | |
295 if (nos >= 2) { | |
296 for (int i = 0; i < nos; i++) { | |
297 BlockBegin* sux = be->sux_at(i); | |
298 if (sux->number_of_preds() >= 2) { | |
299 blocks.append(new BlockPair(bb, sux)); | |
300 } | |
301 } | |
302 } | |
303 } | |
304 | |
305 void split_edges() { | |
306 BlockPair* last_pair = NULL; | |
307 blocks.sort(sort_pairs); | |
308 for (int i = 0; i < blocks.length(); i++) { | |
309 BlockPair* pair = blocks.at(i); | |
310 if (last_pair != NULL && pair->is_same(last_pair)) continue; | |
311 BlockBegin* from = pair->from(); | |
312 BlockBegin* to = pair->to(); | |
313 BlockBegin* split = from->insert_block_between(to); | |
314 #ifndef PRODUCT | |
315 if ((PrintIR || PrintIR1) && Verbose) { | |
316 tty->print_cr("Split critical edge B%d -> B%d (new block B%d)", | |
317 from->block_id(), to->block_id(), split->block_id()); | |
318 } | |
319 #endif | |
320 last_pair = pair; | |
321 } | |
322 } | |
323 }; | |
324 | |
325 void IR::split_critical_edges() { | |
326 CriticalEdgeFinder cef(this); | |
327 | |
328 iterate_preorder(&cef); | |
329 cef.split_edges(); | |
330 } | |
331 | |
332 | |
1584 | 333 class UseCountComputer: public ValueVisitor, BlockClosure { |
0 | 334 private: |
1584 | 335 void visit(Value* n) { |
0 | 336 // Local instructions and Phis for expression stack values at the |
337 // start of basic blocks are not added to the instruction list | |
1899 | 338 if (!(*n)->is_linked() && (*n)->can_be_linked()) { |
0 | 339 assert(false, "a node was not appended to the graph"); |
1584 | 340 Compilation::current()->bailout("a node was not appended to the graph"); |
0 | 341 } |
342 // use n's input if not visited before | |
343 if (!(*n)->is_pinned() && !(*n)->has_uses()) { | |
344 // note: a) if the instruction is pinned, it will be handled by compute_use_count | |
345 // b) if the instruction has uses, it was touched before | |
346 // => in both cases we don't need to update n's values | |
347 uses_do(n); | |
348 } | |
349 // use n | |
350 (*n)->_use_count++; | |
351 } | |
352 | |
1584 | 353 Values* worklist; |
354 int depth; | |
0 | 355 enum { |
356 max_recurse_depth = 20 | |
357 }; | |
358 | |
1584 | 359 void uses_do(Value* n) { |
0 | 360 depth++; |
361 if (depth > max_recurse_depth) { | |
362 // don't allow the traversal to recurse too deeply | |
363 worklist->push(*n); | |
364 } else { | |
1584 | 365 (*n)->input_values_do(this); |
0 | 366 // special handling for some instructions |
367 if ((*n)->as_BlockEnd() != NULL) { | |
368 // note on BlockEnd: | |
369 // must 'use' the stack only if the method doesn't | |
370 // terminate, however, in those cases stack is empty | |
1584 | 371 (*n)->state_values_do(this); |
0 | 372 } |
373 } | |
374 depth--; | |
375 } | |
376 | |
1584 | 377 void block_do(BlockBegin* b) { |
0 | 378 depth = 0; |
379 // process all pinned nodes as the roots of expression trees | |
380 for (Instruction* n = b; n != NULL; n = n->next()) { | |
381 if (n->is_pinned()) uses_do(&n); | |
382 } | |
383 assert(depth == 0, "should have counted back down"); | |
384 | |
385 // now process any unpinned nodes which recursed too deeply | |
386 while (worklist->length() > 0) { | |
387 Value t = worklist->pop(); | |
388 if (!t->is_pinned()) { | |
389 // compute the use count | |
390 uses_do(&t); | |
391 | |
392 // pin the instruction so that LIRGenerator doesn't recurse | |
393 // too deeply during it's evaluation. | |
394 t->pin(); | |
395 } | |
396 } | |
397 assert(depth == 0, "should have counted back down"); | |
398 } | |
399 | |
1584 | 400 UseCountComputer() { |
401 worklist = new Values(); | |
402 depth = 0; | |
403 } | |
404 | |
0 | 405 public: |
406 static void compute(BlockList* blocks) { | |
1584 | 407 UseCountComputer ucc; |
408 blocks->iterate_backward(&ucc); | |
0 | 409 } |
410 }; | |
411 | |
412 | |
413 // helper macro for short definition of trace-output inside code | |
414 #ifndef PRODUCT | |
415 #define TRACE_LINEAR_SCAN(level, code) \ | |
416 if (TraceLinearScanLevel >= level) { \ | |
417 code; \ | |
418 } | |
419 #else | |
420 #define TRACE_LINEAR_SCAN(level, code) | |
421 #endif | |
422 | |
423 class ComputeLinearScanOrder : public StackObj { | |
424 private: | |
425 int _max_block_id; // the highest block_id of a block | |
426 int _num_blocks; // total number of blocks (smaller than _max_block_id) | |
427 int _num_loops; // total number of loops | |
428 bool _iterative_dominators;// method requires iterative computation of dominatiors | |
429 | |
430 BlockList* _linear_scan_order; // the resulting list of blocks in correct order | |
431 | |
432 BitMap _visited_blocks; // used for recursive processing of blocks | |
433 BitMap _active_blocks; // used for recursive processing of blocks | |
434 BitMap _dominator_blocks; // temproary BitMap used for computation of dominator | |
435 intArray _forward_branches; // number of incoming forward branches for each block | |
436 BlockList _loop_end_blocks; // list of all loop end blocks collected during count_edges | |
437 BitMap2D _loop_map; // two-dimensional bit set: a bit is set if a block is contained in a loop | |
438 BlockList _work_list; // temporary list (used in mark_loops and compute_order) | |
8860 | 439 BlockList _loop_headers; |
0 | 440 |
1783 | 441 Compilation* _compilation; |
442 | |
0 | 443 // accessors for _visited_blocks and _active_blocks |
444 void init_visited() { _active_blocks.clear(); _visited_blocks.clear(); } | |
445 bool is_visited(BlockBegin* b) const { return _visited_blocks.at(b->block_id()); } | |
446 bool is_active(BlockBegin* b) const { return _active_blocks.at(b->block_id()); } | |
447 void set_visited(BlockBegin* b) { assert(!is_visited(b), "already set"); _visited_blocks.set_bit(b->block_id()); } | |
448 void set_active(BlockBegin* b) { assert(!is_active(b), "already set"); _active_blocks.set_bit(b->block_id()); } | |
449 void clear_active(BlockBegin* b) { assert(is_active(b), "not already"); _active_blocks.clear_bit(b->block_id()); } | |
450 | |
451 // accessors for _forward_branches | |
452 void inc_forward_branches(BlockBegin* b) { _forward_branches.at_put(b->block_id(), _forward_branches.at(b->block_id()) + 1); } | |
453 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()); } | |
454 | |
455 // accessors for _loop_map | |
456 bool is_block_in_loop (int loop_idx, BlockBegin* b) const { return _loop_map.at(loop_idx, b->block_id()); } | |
457 void set_block_in_loop (int loop_idx, BlockBegin* b) { _loop_map.set_bit(loop_idx, b->block_id()); } | |
458 void clear_block_in_loop(int loop_idx, int block_id) { _loop_map.clear_bit(loop_idx, block_id); } | |
459 | |
460 // count edges between blocks | |
461 void count_edges(BlockBegin* cur, BlockBegin* parent); | |
462 | |
463 // loop detection | |
464 void mark_loops(); | |
465 void clear_non_natural_loops(BlockBegin* start_block); | |
466 void assign_loop_depth(BlockBegin* start_block); | |
467 | |
468 // computation of final block order | |
469 BlockBegin* common_dominator(BlockBegin* a, BlockBegin* b); | |
470 void compute_dominator(BlockBegin* cur, BlockBegin* parent); | |
471 int compute_weight(BlockBegin* cur); | |
472 bool ready_for_processing(BlockBegin* cur); | |
473 void sort_into_work_list(BlockBegin* b); | |
474 void append_block(BlockBegin* cur); | |
475 void compute_order(BlockBegin* start_block); | |
476 | |
477 // fixup of dominators for non-natural loops | |
478 bool compute_dominators_iter(); | |
479 void compute_dominators(); | |
480 | |
481 // debug functions | |
482 NOT_PRODUCT(void print_blocks();) | |
483 DEBUG_ONLY(void verify();) | |
484 | |
1783 | 485 Compilation* compilation() const { return _compilation; } |
0 | 486 public: |
1783 | 487 ComputeLinearScanOrder(Compilation* c, BlockBegin* start_block); |
0 | 488 |
489 // accessors for final result | |
490 BlockList* linear_scan_order() const { return _linear_scan_order; } | |
491 int num_loops() const { return _num_loops; } | |
492 }; | |
493 | |
494 | |
1783 | 495 ComputeLinearScanOrder::ComputeLinearScanOrder(Compilation* c, BlockBegin* start_block) : |
0 | 496 _max_block_id(BlockBegin::number_of_blocks()), |
497 _num_blocks(0), | |
498 _num_loops(0), | |
499 _iterative_dominators(false), | |
500 _visited_blocks(_max_block_id), | |
501 _active_blocks(_max_block_id), | |
502 _dominator_blocks(_max_block_id), | |
503 _forward_branches(_max_block_id, 0), | |
504 _loop_end_blocks(8), | |
505 _work_list(8), | |
506 _linear_scan_order(NULL), // initialized later with correct size | |
1783 | 507 _loop_map(0, 0), // initialized later with correct size |
508 _compilation(c) | |
0 | 509 { |
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510 TRACE_LINEAR_SCAN(2, tty->print_cr("***** computing linear-scan block order")); |
0 | 511 |
512 init_visited(); | |
513 count_edges(start_block, NULL); | |
514 | |
1783 | 515 if (compilation()->is_profiling()) { |
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516 ciMethod *method = compilation()->method(); |
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517 if (!method->is_accessor()) { |
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518 ciMethodData* md = method->method_data_or_null(); |
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519 assert(md != NULL, "Sanity"); |
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520 md->set_compilation_stats(_num_loops, _num_blocks); |
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521 } |
1783 | 522 } |
523 | |
0 | 524 if (_num_loops > 0) { |
525 mark_loops(); | |
526 clear_non_natural_loops(start_block); | |
527 assign_loop_depth(start_block); | |
528 } | |
529 | |
530 compute_order(start_block); | |
531 compute_dominators(); | |
532 | |
533 NOT_PRODUCT(print_blocks()); | |
534 DEBUG_ONLY(verify()); | |
535 } | |
536 | |
537 | |
538 // Traverse the CFG: | |
539 // * count total number of blocks | |
540 // * count all incoming edges and backward incoming edges | |
541 // * number loop header blocks | |
542 // * create a list with all loop end blocks | |
543 void ComputeLinearScanOrder::count_edges(BlockBegin* cur, BlockBegin* parent) { | |
544 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)); | |
545 assert(cur->dominator() == NULL, "dominator already initialized"); | |
546 | |
547 if (is_active(cur)) { | |
548 TRACE_LINEAR_SCAN(3, tty->print_cr("backward branch")); | |
549 assert(is_visited(cur), "block must be visisted when block is active"); | |
550 assert(parent != NULL, "must have parent"); | |
551 | |
552 cur->set(BlockBegin::linear_scan_loop_header_flag); | |
553 cur->set(BlockBegin::backward_branch_target_flag); | |
554 | |
555 parent->set(BlockBegin::linear_scan_loop_end_flag); | |
428
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556 |
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557 // When a loop header is also the start of an exception handler, then the backward branch is |
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558 // an exception edge. Because such edges are usually critical edges which cannot be split, the |
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559 // loop must be excluded here from processing. |
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560 if (cur->is_set(BlockBegin::exception_entry_flag)) { |
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561 // Make sure that dominators are correct in this weird situation |
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562 _iterative_dominators = true; |
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563 return; |
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564 } |
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565 assert(parent->number_of_sux() == 1 && parent->sux_at(0) == cur, |
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566 "loop end blocks must have one successor (critical edges are split)"); |
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567 |
0 | 568 _loop_end_blocks.append(parent); |
569 return; | |
570 } | |
571 | |
572 // increment number of incoming forward branches | |
573 inc_forward_branches(cur); | |
574 | |
575 if (is_visited(cur)) { | |
576 TRACE_LINEAR_SCAN(3, tty->print_cr("block already visited")); | |
577 return; | |
578 } | |
579 | |
580 _num_blocks++; | |
581 set_visited(cur); | |
582 set_active(cur); | |
583 | |
584 // recursive call for all successors | |
585 int i; | |
586 for (i = cur->number_of_sux() - 1; i >= 0; i--) { | |
587 count_edges(cur->sux_at(i), cur); | |
588 } | |
589 for (i = cur->number_of_exception_handlers() - 1; i >= 0; i--) { | |
590 count_edges(cur->exception_handler_at(i), cur); | |
591 } | |
592 | |
593 clear_active(cur); | |
594 | |
595 // Each loop has a unique number. | |
596 // When multiple loops are nested, assign_loop_depth assumes that the | |
597 // innermost loop has the lowest number. This is guaranteed by setting | |
598 // the loop number after the recursive calls for the successors above | |
599 // have returned. | |
600 if (cur->is_set(BlockBegin::linear_scan_loop_header_flag)) { | |
601 assert(cur->loop_index() == -1, "cannot set loop-index twice"); | |
602 TRACE_LINEAR_SCAN(3, tty->print_cr("Block B%d is loop header of loop %d", cur->block_id(), _num_loops)); | |
603 | |
604 cur->set_loop_index(_num_loops); | |
8860 | 605 _loop_headers.append(cur); |
0 | 606 _num_loops++; |
607 } | |
608 | |
609 TRACE_LINEAR_SCAN(3, tty->print_cr("Finished count_edges for block B%d", cur->block_id())); | |
610 } | |
611 | |
612 | |
613 void ComputeLinearScanOrder::mark_loops() { | |
614 TRACE_LINEAR_SCAN(3, tty->print_cr("----- marking loops")); | |
615 | |
616 _loop_map = BitMap2D(_num_loops, _max_block_id); | |
617 _loop_map.clear(); | |
618 | |
619 for (int i = _loop_end_blocks.length() - 1; i >= 0; i--) { | |
620 BlockBegin* loop_end = _loop_end_blocks.at(i); | |
621 BlockBegin* loop_start = loop_end->sux_at(0); | |
622 int loop_idx = loop_start->loop_index(); | |
623 | |
624 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)); | |
625 assert(loop_end->is_set(BlockBegin::linear_scan_loop_end_flag), "loop end flag must be set"); | |
626 assert(loop_end->number_of_sux() == 1, "incorrect number of successors"); | |
627 assert(loop_start->is_set(BlockBegin::linear_scan_loop_header_flag), "loop header flag must be set"); | |
628 assert(loop_idx >= 0 && loop_idx < _num_loops, "loop index not set"); | |
629 assert(_work_list.is_empty(), "work list must be empty before processing"); | |
630 | |
631 // add the end-block of the loop to the working list | |
632 _work_list.push(loop_end); | |
633 set_block_in_loop(loop_idx, loop_end); | |
634 do { | |
635 BlockBegin* cur = _work_list.pop(); | |
636 | |
637 TRACE_LINEAR_SCAN(3, tty->print_cr(" processing B%d", cur->block_id())); | |
638 assert(is_block_in_loop(loop_idx, cur), "bit in loop map must be set when block is in work list"); | |
639 | |
640 // recursive processing of all predecessors ends when start block of loop is reached | |
641 if (cur != loop_start && !cur->is_set(BlockBegin::osr_entry_flag)) { | |
642 for (int j = cur->number_of_preds() - 1; j >= 0; j--) { | |
643 BlockBegin* pred = cur->pred_at(j); | |
644 | |
645 if (!is_block_in_loop(loop_idx, pred) /*&& !pred->is_set(BlockBeginosr_entry_flag)*/) { | |
646 // this predecessor has not been processed yet, so add it to work list | |
647 TRACE_LINEAR_SCAN(3, tty->print_cr(" pushing B%d", pred->block_id())); | |
648 _work_list.push(pred); | |
649 set_block_in_loop(loop_idx, pred); | |
650 } | |
651 } | |
652 } | |
653 } while (!_work_list.is_empty()); | |
654 } | |
655 } | |
656 | |
657 | |
658 // check for non-natural loops (loops where the loop header does not dominate | |
659 // all other loop blocks = loops with mulitple entries). | |
660 // such loops are ignored | |
661 void ComputeLinearScanOrder::clear_non_natural_loops(BlockBegin* start_block) { | |
662 for (int i = _num_loops - 1; i >= 0; i--) { | |
663 if (is_block_in_loop(i, start_block)) { | |
664 // loop i contains the entry block of the method | |
665 // -> this is not a natural loop, so ignore it | |
666 TRACE_LINEAR_SCAN(2, tty->print_cr("Loop %d is non-natural, so it is ignored", i)); | |
667 | |
8860 | 668 BlockBegin *loop_header = _loop_headers.at(i); |
669 assert(loop_header->is_set(BlockBegin::linear_scan_loop_header_flag), "Must be loop header"); | |
670 | |
671 for (int j = 0; j < loop_header->number_of_preds(); j++) { | |
672 BlockBegin *pred = loop_header->pred_at(j); | |
673 pred->clear(BlockBegin::linear_scan_loop_end_flag); | |
674 } | |
675 | |
676 loop_header->clear(BlockBegin::linear_scan_loop_header_flag); | |
677 | |
0 | 678 for (int block_id = _max_block_id - 1; block_id >= 0; block_id--) { |
679 clear_block_in_loop(i, block_id); | |
680 } | |
681 _iterative_dominators = true; | |
682 } | |
683 } | |
684 } | |
685 | |
686 void ComputeLinearScanOrder::assign_loop_depth(BlockBegin* start_block) { | |
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687 TRACE_LINEAR_SCAN(3, tty->print_cr("----- computing loop-depth and weight")); |
0 | 688 init_visited(); |
689 | |
690 assert(_work_list.is_empty(), "work list must be empty before processing"); | |
691 _work_list.append(start_block); | |
692 | |
693 do { | |
694 BlockBegin* cur = _work_list.pop(); | |
695 | |
696 if (!is_visited(cur)) { | |
697 set_visited(cur); | |
698 TRACE_LINEAR_SCAN(4, tty->print_cr("Computing loop depth for block B%d", cur->block_id())); | |
699 | |
700 // compute loop-depth and loop-index for the block | |
701 assert(cur->loop_depth() == 0, "cannot set loop-depth twice"); | |
702 int i; | |
703 int loop_depth = 0; | |
704 int min_loop_idx = -1; | |
705 for (i = _num_loops - 1; i >= 0; i--) { | |
706 if (is_block_in_loop(i, cur)) { | |
707 loop_depth++; | |
708 min_loop_idx = i; | |
709 } | |
710 } | |
711 cur->set_loop_depth(loop_depth); | |
712 cur->set_loop_index(min_loop_idx); | |
713 | |
714 // append all unvisited successors to work list | |
715 for (i = cur->number_of_sux() - 1; i >= 0; i--) { | |
716 _work_list.append(cur->sux_at(i)); | |
717 } | |
718 for (i = cur->number_of_exception_handlers() - 1; i >= 0; i--) { | |
719 _work_list.append(cur->exception_handler_at(i)); | |
720 } | |
721 } | |
722 } while (!_work_list.is_empty()); | |
723 } | |
724 | |
725 | |
726 BlockBegin* ComputeLinearScanOrder::common_dominator(BlockBegin* a, BlockBegin* b) { | |
727 assert(a != NULL && b != NULL, "must have input blocks"); | |
728 | |
729 _dominator_blocks.clear(); | |
730 while (a != NULL) { | |
731 _dominator_blocks.set_bit(a->block_id()); | |
732 assert(a->dominator() != NULL || a == _linear_scan_order->at(0), "dominator must be initialized"); | |
733 a = a->dominator(); | |
734 } | |
735 while (b != NULL && !_dominator_blocks.at(b->block_id())) { | |
736 assert(b->dominator() != NULL || b == _linear_scan_order->at(0), "dominator must be initialized"); | |
737 b = b->dominator(); | |
738 } | |
739 | |
740 assert(b != NULL, "could not find dominator"); | |
741 return b; | |
742 } | |
743 | |
744 void ComputeLinearScanOrder::compute_dominator(BlockBegin* cur, BlockBegin* parent) { | |
745 if (cur->dominator() == NULL) { | |
746 TRACE_LINEAR_SCAN(4, tty->print_cr("DOM: initializing dominator of B%d to B%d", cur->block_id(), parent->block_id())); | |
747 cur->set_dominator(parent); | |
748 | |
749 } else if (!(cur->is_set(BlockBegin::linear_scan_loop_header_flag) && parent->is_set(BlockBegin::linear_scan_loop_end_flag))) { | |
750 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())); | |
8860 | 751 // Does not hold for exception blocks |
752 assert(cur->number_of_preds() > 1 || cur->is_set(BlockBegin::exception_entry_flag), ""); | |
0 | 753 cur->set_dominator(common_dominator(cur->dominator(), parent)); |
754 } | |
8860 | 755 |
756 // Additional edge to xhandler of all our successors | |
757 // range check elimination needs that the state at the end of a | |
758 // block be valid in every block it dominates so cur must dominate | |
759 // the exception handlers of its successors. | |
760 int num_cur_xhandler = cur->number_of_exception_handlers(); | |
761 for (int j = 0; j < num_cur_xhandler; j++) { | |
762 BlockBegin* xhandler = cur->exception_handler_at(j); | |
763 compute_dominator(xhandler, parent); | |
764 } | |
0 | 765 } |
766 | |
767 | |
768 int ComputeLinearScanOrder::compute_weight(BlockBegin* cur) { | |
769 BlockBegin* single_sux = NULL; | |
770 if (cur->number_of_sux() == 1) { | |
771 single_sux = cur->sux_at(0); | |
772 } | |
773 | |
774 // limit loop-depth to 15 bit (only for security reason, it will never be so big) | |
775 int weight = (cur->loop_depth() & 0x7FFF) << 16; | |
776 | |
777 // general macro for short definition of weight flags | |
778 // the first instance of INC_WEIGHT_IF has the highest priority | |
779 int cur_bit = 15; | |
780 #define INC_WEIGHT_IF(condition) if ((condition)) { weight |= (1 << cur_bit); } cur_bit--; | |
781 | |
782 // this is necessery for the (very rare) case that two successing blocks have | |
783 // the same loop depth, but a different loop index (can happen for endless loops | |
784 // with exception handlers) | |
785 INC_WEIGHT_IF(!cur->is_set(BlockBegin::linear_scan_loop_header_flag)); | |
786 | |
787 // loop end blocks (blocks that end with a backward branch) are added | |
788 // after all other blocks of the loop. | |
789 INC_WEIGHT_IF(!cur->is_set(BlockBegin::linear_scan_loop_end_flag)); | |
790 | |
791 // critical edge split blocks are prefered because than they have a bigger | |
792 // proability to be completely empty | |
793 INC_WEIGHT_IF(cur->is_set(BlockBegin::critical_edge_split_flag)); | |
794 | |
795 // exceptions should not be thrown in normal control flow, so these blocks | |
796 // are added as late as possible | |
797 INC_WEIGHT_IF(cur->end()->as_Throw() == NULL && (single_sux == NULL || single_sux->end()->as_Throw() == NULL)); | |
798 INC_WEIGHT_IF(cur->end()->as_Return() == NULL && (single_sux == NULL || single_sux->end()->as_Return() == NULL)); | |
799 | |
800 // exceptions handlers are added as late as possible | |
801 INC_WEIGHT_IF(!cur->is_set(BlockBegin::exception_entry_flag)); | |
802 | |
803 // guarantee that weight is > 0 | |
804 weight |= 1; | |
805 | |
806 #undef INC_WEIGHT_IF | |
807 assert(cur_bit >= 0, "too many flags"); | |
808 assert(weight > 0, "weight cannot become negative"); | |
809 | |
810 return weight; | |
811 } | |
812 | |
813 bool ComputeLinearScanOrder::ready_for_processing(BlockBegin* cur) { | |
814 // Discount the edge just traveled. | |
815 // When the number drops to zero, all forward branches were processed | |
816 if (dec_forward_branches(cur) != 0) { | |
817 return false; | |
818 } | |
819 | |
820 assert(_linear_scan_order->index_of(cur) == -1, "block already processed (block can be ready only once)"); | |
821 assert(_work_list.index_of(cur) == -1, "block already in work-list (block can be ready only once)"); | |
822 return true; | |
823 } | |
824 | |
825 void ComputeLinearScanOrder::sort_into_work_list(BlockBegin* cur) { | |
826 assert(_work_list.index_of(cur) == -1, "block already in work list"); | |
827 | |
828 int cur_weight = compute_weight(cur); | |
829 | |
830 // the linear_scan_number is used to cache the weight of a block | |
831 cur->set_linear_scan_number(cur_weight); | |
832 | |
833 #ifndef PRODUCT | |
834 if (StressLinearScan) { | |
835 _work_list.insert_before(0, cur); | |
836 return; | |
837 } | |
838 #endif | |
839 | |
840 _work_list.append(NULL); // provide space for new element | |
841 | |
842 int insert_idx = _work_list.length() - 1; | |
843 while (insert_idx > 0 && _work_list.at(insert_idx - 1)->linear_scan_number() > cur_weight) { | |
844 _work_list.at_put(insert_idx, _work_list.at(insert_idx - 1)); | |
845 insert_idx--; | |
846 } | |
847 _work_list.at_put(insert_idx, cur); | |
848 | |
849 TRACE_LINEAR_SCAN(3, tty->print_cr("Sorted B%d into worklist. new worklist:", cur->block_id())); | |
850 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())); | |
851 | |
852 #ifdef ASSERT | |
853 for (int i = 0; i < _work_list.length(); i++) { | |
854 assert(_work_list.at(i)->linear_scan_number() > 0, "weight not set"); | |
855 assert(i == 0 || _work_list.at(i - 1)->linear_scan_number() <= _work_list.at(i)->linear_scan_number(), "incorrect order in worklist"); | |
856 } | |
857 #endif | |
858 } | |
859 | |
860 void ComputeLinearScanOrder::append_block(BlockBegin* cur) { | |
861 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())); | |
862 assert(_linear_scan_order->index_of(cur) == -1, "cannot add the same block twice"); | |
863 | |
864 // currently, the linear scan order and code emit order are equal. | |
865 // therefore the linear_scan_number and the weight of a block must also | |
866 // be equal. | |
867 cur->set_linear_scan_number(_linear_scan_order->length()); | |
868 _linear_scan_order->append(cur); | |
869 } | |
870 | |
871 void ComputeLinearScanOrder::compute_order(BlockBegin* start_block) { | |
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872 TRACE_LINEAR_SCAN(3, tty->print_cr("----- computing final block order")); |
0 | 873 |
874 // the start block is always the first block in the linear scan order | |
875 _linear_scan_order = new BlockList(_num_blocks); | |
876 append_block(start_block); | |
877 | |
878 assert(start_block->end()->as_Base() != NULL, "start block must end with Base-instruction"); | |
879 BlockBegin* std_entry = ((Base*)start_block->end())->std_entry(); | |
880 BlockBegin* osr_entry = ((Base*)start_block->end())->osr_entry(); | |
881 | |
882 BlockBegin* sux_of_osr_entry = NULL; | |
883 if (osr_entry != NULL) { | |
884 // special handling for osr entry: | |
885 // ignore the edge between the osr entry and its successor for processing | |
886 // the osr entry block is added manually below | |
887 assert(osr_entry->number_of_sux() == 1, "osr entry must have exactly one successor"); | |
888 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"); | |
889 | |
890 sux_of_osr_entry = osr_entry->sux_at(0); | |
891 dec_forward_branches(sux_of_osr_entry); | |
892 | |
893 compute_dominator(osr_entry, start_block); | |
894 _iterative_dominators = true; | |
895 } | |
896 compute_dominator(std_entry, start_block); | |
897 | |
898 // start processing with standard entry block | |
899 assert(_work_list.is_empty(), "list must be empty before processing"); | |
900 | |
901 if (ready_for_processing(std_entry)) { | |
902 sort_into_work_list(std_entry); | |
903 } else { | |
904 assert(false, "the std_entry must be ready for processing (otherwise, the method has no start block)"); | |
905 } | |
906 | |
907 do { | |
908 BlockBegin* cur = _work_list.pop(); | |
909 | |
910 if (cur == sux_of_osr_entry) { | |
911 // the osr entry block is ignored in normal processing, it is never added to the | |
912 // work list. Instead, it is added as late as possible manually here. | |
913 append_block(osr_entry); | |
914 compute_dominator(cur, osr_entry); | |
915 } | |
916 append_block(cur); | |
917 | |
918 int i; | |
919 int num_sux = cur->number_of_sux(); | |
920 // changed loop order to get "intuitive" order of if- and else-blocks | |
921 for (i = 0; i < num_sux; i++) { | |
922 BlockBegin* sux = cur->sux_at(i); | |
923 compute_dominator(sux, cur); | |
924 if (ready_for_processing(sux)) { | |
925 sort_into_work_list(sux); | |
926 } | |
927 } | |
928 num_sux = cur->number_of_exception_handlers(); | |
929 for (i = 0; i < num_sux; i++) { | |
930 BlockBegin* sux = cur->exception_handler_at(i); | |
931 if (ready_for_processing(sux)) { | |
932 sort_into_work_list(sux); | |
933 } | |
934 } | |
935 } while (_work_list.length() > 0); | |
936 } | |
937 | |
938 | |
939 bool ComputeLinearScanOrder::compute_dominators_iter() { | |
940 bool changed = false; | |
941 int num_blocks = _linear_scan_order->length(); | |
942 | |
943 assert(_linear_scan_order->at(0)->dominator() == NULL, "must not have dominator"); | |
944 assert(_linear_scan_order->at(0)->number_of_preds() == 0, "must not have predecessors"); | |
945 for (int i = 1; i < num_blocks; i++) { | |
946 BlockBegin* block = _linear_scan_order->at(i); | |
947 | |
948 BlockBegin* dominator = block->pred_at(0); | |
949 int num_preds = block->number_of_preds(); | |
8860 | 950 |
951 TRACE_LINEAR_SCAN(4, tty->print_cr("DOM: Processing B%d", block->block_id())); | |
952 | |
953 for (int j = 0; j < num_preds; j++) { | |
954 | |
955 BlockBegin *pred = block->pred_at(j); | |
956 TRACE_LINEAR_SCAN(4, tty->print_cr(" DOM: Subrocessing B%d", pred->block_id())); | |
957 | |
958 if (block->is_set(BlockBegin::exception_entry_flag)) { | |
959 dominator = common_dominator(dominator, pred); | |
960 int num_pred_preds = pred->number_of_preds(); | |
961 for (int k = 0; k < num_pred_preds; k++) { | |
962 dominator = common_dominator(dominator, pred->pred_at(k)); | |
963 } | |
964 } else { | |
965 dominator = common_dominator(dominator, pred); | |
966 } | |
0 | 967 } |
968 | |
969 if (dominator != block->dominator()) { | |
970 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())); | |
971 | |
972 block->set_dominator(dominator); | |
973 changed = true; | |
974 } | |
975 } | |
976 return changed; | |
977 } | |
978 | |
979 void ComputeLinearScanOrder::compute_dominators() { | |
980 TRACE_LINEAR_SCAN(3, tty->print_cr("----- computing dominators (iterative computation reqired: %d)", _iterative_dominators)); | |
981 | |
982 // iterative computation of dominators is only required for methods with non-natural loops | |
983 // and OSR-methods. For all other methods, the dominators computed when generating the | |
984 // linear scan block order are correct. | |
985 if (_iterative_dominators) { | |
986 do { | |
987 TRACE_LINEAR_SCAN(1, tty->print_cr("DOM: next iteration of fix-point calculation")); | |
988 } while (compute_dominators_iter()); | |
989 } | |
990 | |
991 // check that dominators are correct | |
992 assert(!compute_dominators_iter(), "fix point not reached"); | |
8860 | 993 |
994 // Add Blocks to dominates-Array | |
995 int num_blocks = _linear_scan_order->length(); | |
996 for (int i = 0; i < num_blocks; i++) { | |
997 BlockBegin* block = _linear_scan_order->at(i); | |
998 | |
999 BlockBegin *dom = block->dominator(); | |
1000 if (dom) { | |
1001 assert(dom->dominator_depth() != -1, "Dominator must have been visited before"); | |
1002 dom->dominates()->append(block); | |
1003 block->set_dominator_depth(dom->dominator_depth() + 1); | |
1004 } else { | |
1005 block->set_dominator_depth(0); | |
1006 } | |
1007 } | |
0 | 1008 } |
1009 | |
1010 | |
1011 #ifndef PRODUCT | |
1012 void ComputeLinearScanOrder::print_blocks() { | |
1013 if (TraceLinearScanLevel >= 2) { | |
1014 tty->print_cr("----- loop information:"); | |
1015 for (int block_idx = 0; block_idx < _linear_scan_order->length(); block_idx++) { | |
1016 BlockBegin* cur = _linear_scan_order->at(block_idx); | |
1017 | |
1018 tty->print("%4d: B%2d: ", cur->linear_scan_number(), cur->block_id()); | |
1019 for (int loop_idx = 0; loop_idx < _num_loops; loop_idx++) { | |
1020 tty->print ("%d ", is_block_in_loop(loop_idx, cur)); | |
1021 } | |
1022 tty->print_cr(" -> loop_index: %2d, loop_depth: %2d", cur->loop_index(), cur->loop_depth()); | |
1023 } | |
1024 } | |
1025 | |
1026 if (TraceLinearScanLevel >= 1) { | |
1027 tty->print_cr("----- linear-scan block order:"); | |
1028 for (int block_idx = 0; block_idx < _linear_scan_order->length(); block_idx++) { | |
1029 BlockBegin* cur = _linear_scan_order->at(block_idx); | |
1030 tty->print("%4d: B%2d loop: %2d depth: %2d", cur->linear_scan_number(), cur->block_id(), cur->loop_index(), cur->loop_depth()); | |
1031 | |
1032 tty->print(cur->is_set(BlockBegin::exception_entry_flag) ? " ex" : " "); | |
1033 tty->print(cur->is_set(BlockBegin::critical_edge_split_flag) ? " ce" : " "); | |
1034 tty->print(cur->is_set(BlockBegin::linear_scan_loop_header_flag) ? " lh" : " "); | |
1035 tty->print(cur->is_set(BlockBegin::linear_scan_loop_end_flag) ? " le" : " "); | |
1036 | |
1037 if (cur->dominator() != NULL) { | |
1038 tty->print(" dom: B%d ", cur->dominator()->block_id()); | |
1039 } else { | |
1040 tty->print(" dom: NULL "); | |
1041 } | |
1042 | |
1043 if (cur->number_of_preds() > 0) { | |
1044 tty->print(" preds: "); | |
1045 for (int j = 0; j < cur->number_of_preds(); j++) { | |
1046 BlockBegin* pred = cur->pred_at(j); | |
1047 tty->print("B%d ", pred->block_id()); | |
1048 } | |
1049 } | |
1050 if (cur->number_of_sux() > 0) { | |
1051 tty->print(" sux: "); | |
1052 for (int j = 0; j < cur->number_of_sux(); j++) { | |
1053 BlockBegin* sux = cur->sux_at(j); | |
1054 tty->print("B%d ", sux->block_id()); | |
1055 } | |
1056 } | |
1057 if (cur->number_of_exception_handlers() > 0) { | |
1058 tty->print(" ex: "); | |
1059 for (int j = 0; j < cur->number_of_exception_handlers(); j++) { | |
1060 BlockBegin* ex = cur->exception_handler_at(j); | |
1061 tty->print("B%d ", ex->block_id()); | |
1062 } | |
1063 } | |
1064 tty->cr(); | |
1065 } | |
1066 } | |
1067 } | |
1068 #endif | |
1069 | |
1070 #ifdef ASSERT | |
1071 void ComputeLinearScanOrder::verify() { | |
1072 assert(_linear_scan_order->length() == _num_blocks, "wrong number of blocks in list"); | |
1073 | |
1074 if (StressLinearScan) { | |
1075 // blocks are scrambled when StressLinearScan is used | |
1076 return; | |
1077 } | |
1078 | |
1079 // check that all successors of a block have a higher linear-scan-number | |
1080 // and that all predecessors of a block have a lower linear-scan-number | |
1081 // (only backward branches of loops are ignored) | |
1082 int i; | |
1083 for (i = 0; i < _linear_scan_order->length(); i++) { | |
1084 BlockBegin* cur = _linear_scan_order->at(i); | |
1085 | |
1086 assert(cur->linear_scan_number() == i, "incorrect linear_scan_number"); | |
1087 assert(cur->linear_scan_number() >= 0 && cur->linear_scan_number() == _linear_scan_order->index_of(cur), "incorrect linear_scan_number"); | |
1088 | |
1089 int j; | |
1090 for (j = cur->number_of_sux() - 1; j >= 0; j--) { | |
1091 BlockBegin* sux = cur->sux_at(j); | |
1092 | |
1093 assert(sux->linear_scan_number() >= 0 && sux->linear_scan_number() == _linear_scan_order->index_of(sux), "incorrect linear_scan_number"); | |
8860 | 1094 if (!sux->is_set(BlockBegin::backward_branch_target_flag)) { |
0 | 1095 assert(cur->linear_scan_number() < sux->linear_scan_number(), "invalid order"); |
1096 } | |
1097 if (cur->loop_depth() == sux->loop_depth()) { | |
1098 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"); | |
1099 } | |
1100 } | |
1101 | |
1102 for (j = cur->number_of_preds() - 1; j >= 0; j--) { | |
1103 BlockBegin* pred = cur->pred_at(j); | |
1104 | |
1105 assert(pred->linear_scan_number() >= 0 && pred->linear_scan_number() == _linear_scan_order->index_of(pred), "incorrect linear_scan_number"); | |
8860 | 1106 if (!cur->is_set(BlockBegin::backward_branch_target_flag)) { |
0 | 1107 assert(cur->linear_scan_number() > pred->linear_scan_number(), "invalid order"); |
1108 } | |
1109 if (cur->loop_depth() == pred->loop_depth()) { | |
1110 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"); | |
1111 } | |
1112 | |
1113 assert(cur->dominator()->linear_scan_number() <= cur->pred_at(j)->linear_scan_number(), "dominator must be before predecessors"); | |
1114 } | |
1115 | |
1116 // check dominator | |
1117 if (i == 0) { | |
1118 assert(cur->dominator() == NULL, "first block has no dominator"); | |
1119 } else { | |
1120 assert(cur->dominator() != NULL, "all but first block must have dominator"); | |
1121 } | |
8860 | 1122 // Assertion does not hold for exception handlers |
1123 assert(cur->number_of_preds() != 1 || cur->dominator() == cur->pred_at(0) || cur->is_set(BlockBegin::exception_entry_flag), "Single predecessor must also be dominator"); | |
0 | 1124 } |
1125 | |
1126 // check that all loops are continuous | |
1127 for (int loop_idx = 0; loop_idx < _num_loops; loop_idx++) { | |
1128 int block_idx = 0; | |
1129 assert(!is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx)), "the first block must not be present in any loop"); | |
1130 | |
1131 // skip blocks before the loop | |
1132 while (block_idx < _num_blocks && !is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx))) { | |
1133 block_idx++; | |
1134 } | |
1135 // skip blocks of loop | |
1136 while (block_idx < _num_blocks && is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx))) { | |
1137 block_idx++; | |
1138 } | |
1139 // after the first non-loop block, there must not be another loop-block | |
1140 while (block_idx < _num_blocks) { | |
1141 assert(!is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx)), "loop not continuous in linear-scan order"); | |
1142 block_idx++; | |
1143 } | |
1144 } | |
1145 } | |
1146 #endif | |
1147 | |
1148 | |
1149 void IR::compute_code() { | |
1150 assert(is_valid(), "IR must be valid"); | |
1151 | |
1783 | 1152 ComputeLinearScanOrder compute_order(compilation(), start()); |
0 | 1153 _num_loops = compute_order.num_loops(); |
1154 _code = compute_order.linear_scan_order(); | |
1155 } | |
1156 | |
1157 | |
1158 void IR::compute_use_counts() { | |
1159 // make sure all values coming out of this block get evaluated. | |
1160 int num_blocks = _code->length(); | |
1161 for (int i = 0; i < num_blocks; i++) { | |
1162 _code->at(i)->end()->state()->pin_stack_for_linear_scan(); | |
1163 } | |
1164 | |
1165 // compute use counts | |
1166 UseCountComputer::compute(_code); | |
1167 } | |
1168 | |
1169 | |
1170 void IR::iterate_preorder(BlockClosure* closure) { | |
1171 assert(is_valid(), "IR must be valid"); | |
1172 start()->iterate_preorder(closure); | |
1173 } | |
1174 | |
1175 | |
1176 void IR::iterate_postorder(BlockClosure* closure) { | |
1177 assert(is_valid(), "IR must be valid"); | |
1178 start()->iterate_postorder(closure); | |
1179 } | |
1180 | |
1181 void IR::iterate_linear_scan_order(BlockClosure* closure) { | |
1182 linear_scan_order()->iterate_forward(closure); | |
1183 } | |
1184 | |
1185 | |
1186 #ifndef PRODUCT | |
1187 class BlockPrinter: public BlockClosure { | |
1188 private: | |
1189 InstructionPrinter* _ip; | |
1190 bool _cfg_only; | |
1191 bool _live_only; | |
1192 | |
1193 public: | |
1194 BlockPrinter(InstructionPrinter* ip, bool cfg_only, bool live_only = false) { | |
1195 _ip = ip; | |
1196 _cfg_only = cfg_only; | |
1197 _live_only = live_only; | |
1198 } | |
1199 | |
1200 virtual void block_do(BlockBegin* block) { | |
1201 if (_cfg_only) { | |
1202 _ip->print_instr(block); tty->cr(); | |
1203 } else { | |
1204 block->print_block(*_ip, _live_only); | |
1205 } | |
1206 } | |
1207 }; | |
1208 | |
1209 | |
1210 void IR::print(BlockBegin* start, bool cfg_only, bool live_only) { | |
1211 ttyLocker ttyl; | |
1212 InstructionPrinter ip(!cfg_only); | |
1213 BlockPrinter bp(&ip, cfg_only, live_only); | |
1214 start->iterate_preorder(&bp); | |
1215 tty->cr(); | |
1216 } | |
1217 | |
1218 void IR::print(bool cfg_only, bool live_only) { | |
1219 if (is_valid()) { | |
1220 print(start(), cfg_only, live_only); | |
1221 } else { | |
1222 tty->print_cr("invalid IR"); | |
1223 } | |
1224 } | |
1225 | |
1226 | |
1227 define_array(BlockListArray, BlockList*) | |
1228 define_stack(BlockListList, BlockListArray) | |
1229 | |
1230 class PredecessorValidator : public BlockClosure { | |
1231 private: | |
1232 BlockListList* _predecessors; | |
1233 BlockList* _blocks; | |
1234 | |
1235 static int cmp(BlockBegin** a, BlockBegin** b) { | |
1236 return (*a)->block_id() - (*b)->block_id(); | |
1237 } | |
1238 | |
1239 public: | |
1240 PredecessorValidator(IR* hir) { | |
1241 ResourceMark rm; | |
1242 _predecessors = new BlockListList(BlockBegin::number_of_blocks(), NULL); | |
1243 _blocks = new BlockList(); | |
1244 | |
1245 int i; | |
1246 hir->start()->iterate_preorder(this); | |
1247 if (hir->code() != NULL) { | |
1248 assert(hir->code()->length() == _blocks->length(), "must match"); | |
1249 for (i = 0; i < _blocks->length(); i++) { | |
1250 assert(hir->code()->contains(_blocks->at(i)), "should be in both lists"); | |
1251 } | |
1252 } | |
1253 | |
1254 for (i = 0; i < _blocks->length(); i++) { | |
1255 BlockBegin* block = _blocks->at(i); | |
1256 BlockList* preds = _predecessors->at(block->block_id()); | |
1257 if (preds == NULL) { | |
1258 assert(block->number_of_preds() == 0, "should be the same"); | |
1259 continue; | |
1260 } | |
1261 | |
1262 // clone the pred list so we can mutate it | |
1263 BlockList* pred_copy = new BlockList(); | |
1264 int j; | |
1265 for (j = 0; j < block->number_of_preds(); j++) { | |
1266 pred_copy->append(block->pred_at(j)); | |
1267 } | |
1268 // sort them in the same order | |
1269 preds->sort(cmp); | |
1270 pred_copy->sort(cmp); | |
1271 int length = MIN2(preds->length(), block->number_of_preds()); | |
1272 for (j = 0; j < block->number_of_preds(); j++) { | |
1273 assert(preds->at(j) == pred_copy->at(j), "must match"); | |
1274 } | |
1275 | |
1276 assert(preds->length() == block->number_of_preds(), "should be the same"); | |
1277 } | |
1278 } | |
1279 | |
1280 virtual void block_do(BlockBegin* block) { | |
1281 _blocks->append(block); | |
1282 BlockEnd* be = block->end(); | |
1283 int n = be->number_of_sux(); | |
1284 int i; | |
1285 for (i = 0; i < n; i++) { | |
1286 BlockBegin* sux = be->sux_at(i); | |
1287 assert(!sux->is_set(BlockBegin::exception_entry_flag), "must not be xhandler"); | |
1288 | |
1289 BlockList* preds = _predecessors->at_grow(sux->block_id(), NULL); | |
1290 if (preds == NULL) { | |
1291 preds = new BlockList(); | |
1292 _predecessors->at_put(sux->block_id(), preds); | |
1293 } | |
1294 preds->append(block); | |
1295 } | |
1296 | |
1297 n = block->number_of_exception_handlers(); | |
1298 for (i = 0; i < n; i++) { | |
1299 BlockBegin* sux = block->exception_handler_at(i); | |
1300 assert(sux->is_set(BlockBegin::exception_entry_flag), "must be xhandler"); | |
1301 | |
1302 BlockList* preds = _predecessors->at_grow(sux->block_id(), NULL); | |
1303 if (preds == NULL) { | |
1304 preds = new BlockList(); | |
1305 _predecessors->at_put(sux->block_id(), preds); | |
1306 } | |
1307 preds->append(block); | |
1308 } | |
1309 } | |
1310 }; | |
1311 | |
8860 | 1312 class VerifyBlockBeginField : public BlockClosure { |
1313 | |
1314 public: | |
1315 | |
1316 virtual void block_do(BlockBegin *block) { | |
1317 for ( Instruction *cur = block; cur != NULL; cur = cur->next()) { | |
1318 assert(cur->block() == block, "Block begin is not correct"); | |
1319 } | |
1320 } | |
1321 }; | |
1322 | |
0 | 1323 void IR::verify() { |
1324 #ifdef ASSERT | |
1325 PredecessorValidator pv(this); | |
8860 | 1326 VerifyBlockBeginField verifier; |
1327 this->iterate_postorder(&verifier); | |
0 | 1328 #endif |
1329 } | |
1330 | |
1331 #endif // PRODUCT | |
1332 | |
1584 | 1333 void SubstitutionResolver::visit(Value* v) { |
0 | 1334 Value v0 = *v; |
1335 if (v0) { | |
1336 Value vs = v0->subst(); | |
1337 if (vs != v0) { | |
1338 *v = v0->subst(); | |
1339 } | |
1340 } | |
1341 } | |
1342 | |
1343 #ifdef ASSERT | |
1584 | 1344 class SubstitutionChecker: public ValueVisitor { |
1345 void visit(Value* v) { | |
1346 Value v0 = *v; | |
1347 if (v0) { | |
1348 Value vs = v0->subst(); | |
1349 assert(vs == v0, "missed substitution"); | |
1350 } | |
0 | 1351 } |
1584 | 1352 }; |
0 | 1353 #endif |
1354 | |
1355 | |
1356 void SubstitutionResolver::block_do(BlockBegin* block) { | |
1357 Instruction* last = NULL; | |
1358 for (Instruction* n = block; n != NULL;) { | |
1584 | 1359 n->values_do(this); |
0 | 1360 // need to remove this instruction from the instruction stream |
1361 if (n->subst() != n) { | |
1362 assert(last != NULL, "must have last"); | |
1819 | 1363 last->set_next(n->next()); |
0 | 1364 } else { |
1365 last = n; | |
1366 } | |
1367 n = last->next(); | |
1368 } | |
1369 | |
1370 #ifdef ASSERT | |
1584 | 1371 SubstitutionChecker check_substitute; |
1372 if (block->state()) block->state()->values_do(&check_substitute); | |
1373 block->block_values_do(&check_substitute); | |
1374 if (block->end() && block->end()->state()) block->end()->state()->values_do(&check_substitute); | |
0 | 1375 #endif |
1376 } |