29 #include "compiler/methodLiveness.hpp" |
29 #include "compiler/methodLiveness.hpp" |
30 #include "interpreter/bytecode.hpp" |
30 #include "interpreter/bytecode.hpp" |
31 #include "interpreter/bytecodes.hpp" |
31 #include "interpreter/bytecodes.hpp" |
32 #include "memory/allocation.inline.hpp" |
32 #include "memory/allocation.inline.hpp" |
33 #include "memory/resourceArea.hpp" |
33 #include "memory/resourceArea.hpp" |
34 #include "runtime/timerTrace.hpp" |
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35 #include "utilities/bitMap.inline.hpp" |
34 #include "utilities/bitMap.inline.hpp" |
36 |
35 |
37 // The MethodLiveness class performs a simple liveness analysis on a method |
36 // The MethodLiveness class performs a simple liveness analysis on a method |
38 // in order to decide which locals are live (that is, will be used again) at |
37 // in order to decide which locals are live (that is, will be used again) at |
39 // a particular bytecode index (bci). |
38 // a particular bytecode index (bci). |
69 // 2. Instead of computing the effects of exceptions at every instruction, we |
68 // 2. Instead of computing the effects of exceptions at every instruction, we |
70 // summarize the effects of all exceptional continuations from the block as |
69 // summarize the effects of all exceptional continuations from the block as |
71 // a single set (_exception_exit), losing some information but simplifying the |
70 // a single set (_exception_exit), losing some information but simplifying the |
72 // analysis. |
71 // analysis. |
73 |
72 |
74 |
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75 //-------------------------------------------------------------------------- |
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76 // The BitCounter class is used for counting the number of bits set in |
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77 // some BitMap. It is only used when collecting liveness statistics. |
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78 |
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79 #ifndef PRODUCT |
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80 |
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81 class BitCounter: public BitMapClosure { |
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82 private: |
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83 int _count; |
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84 public: |
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85 BitCounter() : _count(0) {} |
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86 |
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87 // Callback when bit in map is set |
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88 virtual bool do_bit(size_t offset) { |
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89 _count++; |
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90 return true; |
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91 } |
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92 |
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93 int count() { |
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94 return _count; |
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95 } |
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96 }; |
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97 |
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98 |
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99 //-------------------------------------------------------------------------- |
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100 |
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101 |
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102 // Counts |
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103 long MethodLiveness::_total_bytes = 0; |
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104 int MethodLiveness::_total_methods = 0; |
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105 |
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106 long MethodLiveness::_total_blocks = 0; |
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107 int MethodLiveness::_max_method_blocks = 0; |
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108 |
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109 long MethodLiveness::_total_edges = 0; |
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110 int MethodLiveness::_max_block_edges = 0; |
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111 |
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112 long MethodLiveness::_total_exc_edges = 0; |
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113 int MethodLiveness::_max_block_exc_edges = 0; |
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114 |
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115 long MethodLiveness::_total_method_locals = 0; |
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116 int MethodLiveness::_max_method_locals = 0; |
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117 |
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118 long MethodLiveness::_total_locals_queried = 0; |
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119 long MethodLiveness::_total_live_locals_queried = 0; |
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120 |
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121 long MethodLiveness::_total_visits = 0; |
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122 |
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123 #endif |
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124 |
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125 // Timers |
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126 elapsedTimer MethodLiveness::_time_build_graph; |
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127 elapsedTimer MethodLiveness::_time_gen_kill; |
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128 elapsedTimer MethodLiveness::_time_flow; |
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129 elapsedTimer MethodLiveness::_time_query; |
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130 elapsedTimer MethodLiveness::_time_total; |
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131 |
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132 MethodLiveness::MethodLiveness(Arena* arena, ciMethod* method) |
73 MethodLiveness::MethodLiveness(Arena* arena, ciMethod* method) |
133 #ifdef COMPILER1 |
74 #ifdef COMPILER1 |
134 : _bci_block_start(arena, method->code_size()) |
75 : _bci_block_start(arena, method->code_size()) |
135 #endif |
76 #endif |
136 { |
77 { |
144 if (TraceLivenessGen) { |
85 if (TraceLivenessGen) { |
145 tty->print_cr("################################################################"); |
86 tty->print_cr("################################################################"); |
146 tty->print("# Computing liveness information for "); |
87 tty->print("# Computing liveness information for "); |
147 method()->print_short_name(); |
88 method()->print_short_name(); |
148 } |
89 } |
149 |
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150 if (TimeLivenessAnalysis) _time_total.start(); |
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151 #endif |
90 #endif |
152 |
91 |
153 { |
92 init_basic_blocks(); |
154 TraceTime buildGraph(NULL, &_time_build_graph, TimeLivenessAnalysis); |
93 init_gen_kill(); |
155 init_basic_blocks(); |
94 propagate_liveness(); |
156 } |
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157 { |
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158 TraceTime genKill(NULL, &_time_gen_kill, TimeLivenessAnalysis); |
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159 init_gen_kill(); |
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160 } |
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161 { |
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162 TraceTime flow(NULL, &_time_flow, TimeLivenessAnalysis); |
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163 propagate_liveness(); |
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164 } |
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165 |
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166 #ifndef PRODUCT |
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167 if (TimeLivenessAnalysis) _time_total.stop(); |
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168 |
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169 if (TimeLivenessAnalysis) { |
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170 // Collect statistics |
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171 _total_bytes += method()->code_size(); |
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172 _total_methods++; |
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173 |
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174 int num_blocks = _block_count; |
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175 _total_blocks += num_blocks; |
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176 _max_method_blocks = MAX2(num_blocks,_max_method_blocks); |
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177 |
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178 for (int i=0; i<num_blocks; i++) { |
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179 BasicBlock *block = _block_list[i]; |
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180 |
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181 int numEdges = block->_normal_predecessors->length(); |
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182 int numExcEdges = block->_exception_predecessors->length(); |
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183 |
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184 _total_edges += numEdges; |
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185 _total_exc_edges += numExcEdges; |
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186 _max_block_edges = MAX2(numEdges,_max_block_edges); |
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187 _max_block_exc_edges = MAX2(numExcEdges,_max_block_exc_edges); |
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188 } |
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189 |
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190 int numLocals = _bit_map_size_bits; |
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191 _total_method_locals += numLocals; |
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192 _max_method_locals = MAX2(numLocals,_max_method_locals); |
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193 } |
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194 #endif |
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195 } |
95 } |
196 |
96 |
197 |
97 |
198 void MethodLiveness::init_basic_blocks() { |
98 void MethodLiveness::init_basic_blocks() { |
199 bool bailout = false; |
99 bool bailout = false; |
499 tty->print("Liveness query of "); |
397 tty->print("Liveness query of "); |
500 method()->print_short_name(); |
398 method()->print_short_name(); |
501 tty->print(" @ %d : result is ", bci); |
399 tty->print(" @ %d : result is ", bci); |
502 answer.print_on(tty); |
400 answer.print_on(tty); |
503 } |
401 } |
504 |
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505 if (TimeLivenessAnalysis) _time_query.stop(); |
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506 if (TimeLivenessAnalysis) _time_total.stop(); |
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507 #endif |
402 #endif |
508 } |
403 } |
509 |
404 |
510 #ifndef PRODUCT |
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511 if (TimeLivenessAnalysis) { |
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512 // Collect statistics. |
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513 _total_locals_queried += _bit_map_size_bits; |
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514 BitCounter counter; |
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515 answer.iterate(&counter); |
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516 _total_live_locals_queried += counter.count(); |
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517 } |
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518 #endif |
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519 |
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520 return answer; |
405 return answer; |
521 } |
406 } |
522 |
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523 |
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524 #ifndef PRODUCT |
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525 |
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526 void MethodLiveness::print_times() { |
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527 tty->print_cr ("Accumulated liveness analysis times/statistics:"); |
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528 tty->print_cr ("-----------------------------------------------"); |
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529 tty->print_cr (" Total : %3.3f sec.", _time_total.seconds()); |
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530 tty->print_cr (" Build graph : %3.3f sec. (%2.2f%%)", _time_build_graph.seconds(), |
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531 _time_build_graph.seconds() * 100 / _time_total.seconds()); |
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532 tty->print_cr (" Gen / Kill : %3.3f sec. (%2.2f%%)", _time_gen_kill.seconds(), |
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533 _time_gen_kill.seconds() * 100 / _time_total.seconds()); |
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534 tty->print_cr (" Dataflow : %3.3f sec. (%2.2f%%)", _time_flow.seconds(), |
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535 _time_flow.seconds() * 100 / _time_total.seconds()); |
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536 tty->print_cr (" Query : %3.3f sec. (%2.2f%%)", _time_query.seconds(), |
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537 _time_query.seconds() * 100 / _time_total.seconds()); |
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538 tty->print_cr (" #bytes : %8ld (%3.0f bytes per sec)", |
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539 _total_bytes, |
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540 _total_bytes / _time_total.seconds()); |
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541 tty->print_cr (" #methods : %8d (%3.0f methods per sec)", |
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542 _total_methods, |
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543 _total_methods / _time_total.seconds()); |
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544 tty->print_cr (" avg locals : %3.3f max locals : %3d", |
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545 (float)_total_method_locals / _total_methods, |
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546 _max_method_locals); |
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547 tty->print_cr (" avg blocks : %3.3f max blocks : %3d", |
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548 (float)_total_blocks / _total_methods, |
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549 _max_method_blocks); |
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550 tty->print_cr (" avg bytes : %3.3f", |
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551 (float)_total_bytes / _total_methods); |
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552 tty->print_cr (" #blocks : %8ld", |
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553 _total_blocks); |
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554 tty->print_cr (" avg normal predecessors : %3.3f max normal predecessors : %3d", |
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555 (float)_total_edges / _total_blocks, |
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556 _max_block_edges); |
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557 tty->print_cr (" avg exception predecessors : %3.3f max exception predecessors : %3d", |
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558 (float)_total_exc_edges / _total_blocks, |
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559 _max_block_exc_edges); |
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560 tty->print_cr (" avg visits : %3.3f", |
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561 (float)_total_visits / _total_blocks); |
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562 tty->print_cr (" #locals queried : %8ld #live : %8ld %%live : %2.2f%%", |
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563 _total_locals_queried, |
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564 _total_live_locals_queried, |
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565 100.0 * _total_live_locals_queried / _total_locals_queried); |
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566 } |
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567 |
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568 #endif |
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569 |
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570 |
407 |
571 MethodLiveness::BasicBlock::BasicBlock(MethodLiveness *analyzer, int start, int limit) : |
408 MethodLiveness::BasicBlock::BasicBlock(MethodLiveness *analyzer, int start, int limit) : |
572 _entry(analyzer->arena(), analyzer->bit_map_size_bits()), |
409 _entry(analyzer->arena(), analyzer->bit_map_size_bits()), |
573 _normal_exit(analyzer->arena(), analyzer->bit_map_size_bits()), |
410 _normal_exit(analyzer->arena(), analyzer->bit_map_size_bits()), |
574 _exception_exit(analyzer->arena(), analyzer->bit_map_size_bits()), |
411 _exception_exit(analyzer->arena(), analyzer->bit_map_size_bits()), |