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1 /* |
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2 * Copyright 1999-2006 Sun Microsystems, Inc. All Rights Reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. |
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8 * |
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9 * This code is distributed in the hope that it will be useful, but WITHOUT |
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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12 * version 2 for more details (a copy is included in the LICENSE file that |
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13 * accompanied this code). |
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14 * |
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15 * You should have received a copy of the GNU General Public License version |
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16 * 2 along with this work; if not, write to the Free Software Foundation, |
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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18 * |
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19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
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20 * CA 95054 USA or visit www.sun.com if you need additional information or |
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21 * have any questions. |
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22 * |
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23 */ |
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24 |
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25 # include "incls/_precompiled.incl" |
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26 # include "incls/_c1_IR.cpp.incl" |
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27 |
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28 |
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29 // Implementation of XHandlers |
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30 // |
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31 // Note: This code could eventually go away if we are |
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32 // just using the ciExceptionHandlerStream. |
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33 |
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34 XHandlers::XHandlers(ciMethod* method) : _list(method->exception_table_length()) { |
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35 ciExceptionHandlerStream s(method); |
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36 while (!s.is_done()) { |
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37 _list.append(new XHandler(s.handler())); |
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38 s.next(); |
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39 } |
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40 assert(s.count() == method->exception_table_length(), "exception table lengths inconsistent"); |
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41 } |
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42 |
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43 // deep copy of all XHandler contained in list |
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44 XHandlers::XHandlers(XHandlers* other) : |
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45 _list(other->length()) |
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46 { |
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47 for (int i = 0; i < other->length(); i++) { |
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48 _list.append(new XHandler(other->handler_at(i))); |
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49 } |
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50 } |
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51 |
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52 // Returns whether a particular exception type can be caught. Also |
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53 // returns true if klass is unloaded or any exception handler |
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54 // classes are unloaded. type_is_exact indicates whether the throw |
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55 // is known to be exactly that class or it might throw a subtype. |
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56 bool XHandlers::could_catch(ciInstanceKlass* klass, bool type_is_exact) const { |
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57 // the type is unknown so be conservative |
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58 if (!klass->is_loaded()) { |
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59 return true; |
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60 } |
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61 |
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62 for (int i = 0; i < length(); i++) { |
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63 XHandler* handler = handler_at(i); |
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64 if (handler->is_catch_all()) { |
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65 // catch of ANY |
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66 return true; |
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67 } |
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68 ciInstanceKlass* handler_klass = handler->catch_klass(); |
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69 // if it's unknown it might be catchable |
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70 if (!handler_klass->is_loaded()) { |
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71 return true; |
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72 } |
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73 // if the throw type is definitely a subtype of the catch type |
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74 // then it can be caught. |
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75 if (klass->is_subtype_of(handler_klass)) { |
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76 return true; |
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77 } |
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78 if (!type_is_exact) { |
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79 // If the type isn't exactly known then it can also be caught by |
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80 // catch statements where the inexact type is a subtype of the |
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81 // catch type. |
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82 // given: foo extends bar extends Exception |
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83 // throw bar can be caught by catch foo, catch bar, and catch |
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84 // Exception, however it can't be caught by any handlers without |
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85 // bar in its type hierarchy. |
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86 if (handler_klass->is_subtype_of(klass)) { |
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87 return true; |
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88 } |
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89 } |
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90 } |
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91 |
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92 return false; |
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93 } |
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94 |
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95 |
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96 bool XHandlers::equals(XHandlers* others) const { |
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97 if (others == NULL) return false; |
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98 if (length() != others->length()) return false; |
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99 |
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100 for (int i = 0; i < length(); i++) { |
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101 if (!handler_at(i)->equals(others->handler_at(i))) return false; |
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102 } |
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103 return true; |
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104 } |
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105 |
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106 bool XHandler::equals(XHandler* other) const { |
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107 assert(entry_pco() != -1 && other->entry_pco() != -1, "must have entry_pco"); |
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108 |
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109 if (entry_pco() != other->entry_pco()) return false; |
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110 if (scope_count() != other->scope_count()) return false; |
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111 if (_desc != other->_desc) return false; |
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112 |
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113 assert(entry_block() == other->entry_block(), "entry_block must be equal when entry_pco is equal"); |
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114 return true; |
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115 } |
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116 |
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117 |
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118 // Implementation of IRScope |
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119 |
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120 BlockBegin* IRScope::header_block(BlockBegin* entry, BlockBegin::Flag f, ValueStack* state) { |
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121 if (entry == NULL) return NULL; |
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122 assert(entry->is_set(f), "entry/flag mismatch"); |
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123 // create header block |
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124 BlockBegin* h = new BlockBegin(entry->bci()); |
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125 BlockEnd* g = new Goto(entry, false); |
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126 h->set_next(g, entry->bci()); |
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127 h->set_end(g); |
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128 h->set(f); |
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129 // setup header block end state |
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130 ValueStack* s = state->copy(); // can use copy since stack is empty (=> no phis) |
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131 assert(s->stack_is_empty(), "must have empty stack at entry point"); |
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132 g->set_state(s); |
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133 return h; |
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134 } |
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135 |
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136 |
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137 BlockBegin* IRScope::build_graph(Compilation* compilation, int osr_bci) { |
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138 GraphBuilder gm(compilation, this); |
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139 NOT_PRODUCT(if (PrintValueNumbering && Verbose) gm.print_stats()); |
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140 if (compilation->bailed_out()) return NULL; |
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141 return gm.start(); |
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142 } |
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143 |
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144 |
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145 IRScope::IRScope(Compilation* compilation, IRScope* caller, int caller_bci, ciMethod* method, int osr_bci, bool create_graph) |
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146 : _callees(2) |
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147 , _compilation(compilation) |
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148 , _lock_stack_size(-1) |
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149 , _requires_phi_function(method->max_locals()) |
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150 { |
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151 _caller = caller; |
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152 _caller_bci = caller == NULL ? -1 : caller_bci; |
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153 _caller_state = NULL; // Must be set later if needed |
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154 _level = caller == NULL ? 0 : caller->level() + 1; |
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155 _method = method; |
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156 _xhandlers = new XHandlers(method); |
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157 _number_of_locks = 0; |
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158 _monitor_pairing_ok = method->has_balanced_monitors(); |
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159 _start = NULL; |
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160 |
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161 if (osr_bci == -1) { |
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162 _requires_phi_function.clear(); |
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163 } else { |
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164 // selective creation of phi functions is not possibel in osr-methods |
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165 _requires_phi_function.set_range(0, method->max_locals()); |
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166 } |
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167 |
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168 assert(method->holder()->is_loaded() , "method holder must be loaded"); |
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169 |
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170 // build graph if monitor pairing is ok |
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171 if (create_graph && monitor_pairing_ok()) _start = build_graph(compilation, osr_bci); |
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172 } |
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173 |
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174 |
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175 int IRScope::max_stack() const { |
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176 int my_max = method()->max_stack(); |
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177 int callee_max = 0; |
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178 for (int i = 0; i < number_of_callees(); i++) { |
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179 callee_max = MAX2(callee_max, callee_no(i)->max_stack()); |
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180 } |
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181 return my_max + callee_max; |
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182 } |
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183 |
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184 |
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185 void IRScope::compute_lock_stack_size() { |
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186 if (!InlineMethodsWithExceptionHandlers) { |
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187 _lock_stack_size = 0; |
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188 return; |
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189 } |
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190 |
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191 // Figure out whether we have to preserve expression stack elements |
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192 // for parent scopes, and if so, how many |
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193 IRScope* cur_scope = this; |
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194 while (cur_scope != NULL && !cur_scope->xhandlers()->has_handlers()) { |
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195 cur_scope = cur_scope->caller(); |
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196 } |
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197 _lock_stack_size = (cur_scope == NULL ? 0 : |
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198 (cur_scope->caller_state() == NULL ? 0 : |
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199 cur_scope->caller_state()->stack_size())); |
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200 } |
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201 |
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202 int IRScope::top_scope_bci() const { |
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203 assert(!is_top_scope(), "no correct answer for top scope possible"); |
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204 const IRScope* scope = this; |
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205 while (!scope->caller()->is_top_scope()) { |
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206 scope = scope->caller(); |
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207 } |
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208 return scope->caller_bci(); |
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209 } |
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210 |
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211 |
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212 |
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213 // Implementation of CodeEmitInfo |
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214 |
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215 // Stack must be NON-null |
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216 CodeEmitInfo::CodeEmitInfo(int bci, ValueStack* stack, XHandlers* exception_handlers) |
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217 : _scope(stack->scope()) |
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218 , _bci(bci) |
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219 , _scope_debug_info(NULL) |
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220 , _oop_map(NULL) |
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221 , _stack(stack) |
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222 , _exception_handlers(exception_handlers) |
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223 , _next(NULL) |
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224 , _id(-1) { |
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225 assert(_stack != NULL, "must be non null"); |
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226 assert(_bci == SynchronizationEntryBCI || Bytecodes::is_defined(scope()->method()->java_code_at_bci(_bci)), "make sure bci points at a real bytecode"); |
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227 } |
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228 |
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229 |
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230 CodeEmitInfo::CodeEmitInfo(CodeEmitInfo* info, bool lock_stack_only) |
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231 : _scope(info->_scope) |
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232 , _exception_handlers(NULL) |
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233 , _bci(info->_bci) |
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234 , _scope_debug_info(NULL) |
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235 , _oop_map(NULL) { |
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236 if (lock_stack_only) { |
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237 if (info->_stack != NULL) { |
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238 _stack = info->_stack->copy_locks(); |
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239 } else { |
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240 _stack = NULL; |
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241 } |
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242 } else { |
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243 _stack = info->_stack; |
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244 } |
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245 |
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246 // deep copy of exception handlers |
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247 if (info->_exception_handlers != NULL) { |
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248 _exception_handlers = new XHandlers(info->_exception_handlers); |
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249 } |
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250 } |
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251 |
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252 |
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253 void CodeEmitInfo::record_debug_info(DebugInformationRecorder* recorder, int pc_offset) { |
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254 // record the safepoint before recording the debug info for enclosing scopes |
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255 recorder->add_safepoint(pc_offset, _oop_map->deep_copy()); |
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256 _scope_debug_info->record_debug_info(recorder, pc_offset); |
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257 recorder->end_safepoint(pc_offset); |
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258 } |
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259 |
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260 |
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261 void CodeEmitInfo::add_register_oop(LIR_Opr opr) { |
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262 assert(_oop_map != NULL, "oop map must already exist"); |
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263 assert(opr->is_single_cpu(), "should not call otherwise"); |
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264 |
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265 int frame_size = frame_map()->framesize(); |
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266 int arg_count = frame_map()->oop_map_arg_count(); |
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267 VMReg name = frame_map()->regname(opr); |
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268 _oop_map->set_oop(name); |
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269 } |
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270 |
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271 |
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272 |
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273 |
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274 // Implementation of IR |
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275 |
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276 IR::IR(Compilation* compilation, ciMethod* method, int osr_bci) : |
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277 _locals_size(in_WordSize(-1)) |
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278 , _num_loops(0) { |
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279 // initialize data structures |
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280 ValueType::initialize(); |
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281 Instruction::initialize(); |
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282 BlockBegin::initialize(); |
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283 GraphBuilder::initialize(); |
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284 // setup IR fields |
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285 _compilation = compilation; |
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286 _top_scope = new IRScope(compilation, NULL, -1, method, osr_bci, true); |
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287 _code = NULL; |
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288 } |
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289 |
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290 |
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291 void IR::optimize() { |
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292 Optimizer opt(this); |
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293 if (DoCEE) { |
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294 opt.eliminate_conditional_expressions(); |
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295 #ifndef PRODUCT |
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296 if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after CEE"); print(true); } |
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297 if (PrintIR || PrintIR1 ) { tty->print_cr("IR after CEE"); print(false); } |
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298 #endif |
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299 } |
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300 if (EliminateBlocks) { |
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301 opt.eliminate_blocks(); |
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302 #ifndef PRODUCT |
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303 if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after block elimination"); print(true); } |
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304 if (PrintIR || PrintIR1 ) { tty->print_cr("IR after block elimination"); print(false); } |
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305 #endif |
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306 } |
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307 if (EliminateNullChecks) { |
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308 opt.eliminate_null_checks(); |
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309 #ifndef PRODUCT |
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310 if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after null check elimination"); print(true); } |
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311 if (PrintIR || PrintIR1 ) { tty->print_cr("IR after null check elimination"); print(false); } |
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312 #endif |
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313 } |
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314 } |
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315 |
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316 |
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317 static int sort_pairs(BlockPair** a, BlockPair** b) { |
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318 if ((*a)->from() == (*b)->from()) { |
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319 return (*a)->to()->block_id() - (*b)->to()->block_id(); |
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320 } else { |
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321 return (*a)->from()->block_id() - (*b)->from()->block_id(); |
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322 } |
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323 } |
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324 |
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325 |
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326 class CriticalEdgeFinder: public BlockClosure { |
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327 BlockPairList blocks; |
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328 IR* _ir; |
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329 |
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330 public: |
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331 CriticalEdgeFinder(IR* ir): _ir(ir) {} |
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332 void block_do(BlockBegin* bb) { |
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333 BlockEnd* be = bb->end(); |
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334 int nos = be->number_of_sux(); |
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335 if (nos >= 2) { |
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336 for (int i = 0; i < nos; i++) { |
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337 BlockBegin* sux = be->sux_at(i); |
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338 if (sux->number_of_preds() >= 2) { |
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339 blocks.append(new BlockPair(bb, sux)); |
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340 } |
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341 } |
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342 } |
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343 } |
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344 |
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345 void split_edges() { |
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346 BlockPair* last_pair = NULL; |
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347 blocks.sort(sort_pairs); |
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348 for (int i = 0; i < blocks.length(); i++) { |
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349 BlockPair* pair = blocks.at(i); |
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350 if (last_pair != NULL && pair->is_same(last_pair)) continue; |
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351 BlockBegin* from = pair->from(); |
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352 BlockBegin* to = pair->to(); |
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353 BlockBegin* split = from->insert_block_between(to); |
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354 #ifndef PRODUCT |
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355 if ((PrintIR || PrintIR1) && Verbose) { |
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356 tty->print_cr("Split critical edge B%d -> B%d (new block B%d)", |
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357 from->block_id(), to->block_id(), split->block_id()); |
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358 } |
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359 #endif |
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360 last_pair = pair; |
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361 } |
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362 } |
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363 }; |
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364 |
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365 void IR::split_critical_edges() { |
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366 CriticalEdgeFinder cef(this); |
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367 |
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368 iterate_preorder(&cef); |
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369 cef.split_edges(); |
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370 } |
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371 |
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372 |
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373 class UseCountComputer: public AllStatic { |
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374 private: |
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375 static void update_use_count(Value* n) { |
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376 // Local instructions and Phis for expression stack values at the |
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377 // start of basic blocks are not added to the instruction list |
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378 if ((*n)->bci() == -99 && (*n)->as_Local() == NULL && |
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379 (*n)->as_Phi() == NULL) { |
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380 assert(false, "a node was not appended to the graph"); |
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381 Compilation::current_compilation()->bailout("a node was not appended to the graph"); |
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382 } |
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383 // use n's input if not visited before |
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384 if (!(*n)->is_pinned() && !(*n)->has_uses()) { |
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385 // note: a) if the instruction is pinned, it will be handled by compute_use_count |
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386 // b) if the instruction has uses, it was touched before |
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387 // => in both cases we don't need to update n's values |
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388 uses_do(n); |
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389 } |
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390 // use n |
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391 (*n)->_use_count++; |
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392 } |
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393 |
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394 static Values* worklist; |
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395 static int depth; |
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396 enum { |
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397 max_recurse_depth = 20 |
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398 }; |
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399 |
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400 static void uses_do(Value* n) { |
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401 depth++; |
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402 if (depth > max_recurse_depth) { |
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403 // don't allow the traversal to recurse too deeply |
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404 worklist->push(*n); |
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405 } else { |
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406 (*n)->input_values_do(update_use_count); |
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407 // special handling for some instructions |
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408 if ((*n)->as_BlockEnd() != NULL) { |
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409 // note on BlockEnd: |
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410 // must 'use' the stack only if the method doesn't |
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411 // terminate, however, in those cases stack is empty |
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412 (*n)->state_values_do(update_use_count); |
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413 } |
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414 } |
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415 depth--; |
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416 } |
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417 |
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418 static void basic_compute_use_count(BlockBegin* b) { |
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419 depth = 0; |
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420 // process all pinned nodes as the roots of expression trees |
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421 for (Instruction* n = b; n != NULL; n = n->next()) { |
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422 if (n->is_pinned()) uses_do(&n); |
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423 } |
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424 assert(depth == 0, "should have counted back down"); |
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425 |
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426 // now process any unpinned nodes which recursed too deeply |
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427 while (worklist->length() > 0) { |
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428 Value t = worklist->pop(); |
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429 if (!t->is_pinned()) { |
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430 // compute the use count |
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431 uses_do(&t); |
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432 |
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433 // pin the instruction so that LIRGenerator doesn't recurse |
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434 // too deeply during it's evaluation. |
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435 t->pin(); |
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436 } |
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437 } |
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438 assert(depth == 0, "should have counted back down"); |
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439 } |
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440 |
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441 public: |
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442 static void compute(BlockList* blocks) { |
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443 worklist = new Values(); |
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444 blocks->blocks_do(basic_compute_use_count); |
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445 worklist = NULL; |
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446 } |
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447 }; |
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448 |
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449 |
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450 Values* UseCountComputer::worklist = NULL; |
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451 int UseCountComputer::depth = 0; |
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452 |
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453 // helper macro for short definition of trace-output inside code |
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454 #ifndef PRODUCT |
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455 #define TRACE_LINEAR_SCAN(level, code) \ |
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456 if (TraceLinearScanLevel >= level) { \ |
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457 code; \ |
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458 } |
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459 #else |
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460 #define TRACE_LINEAR_SCAN(level, code) |
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461 #endif |
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462 |
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463 class ComputeLinearScanOrder : public StackObj { |
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464 private: |
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465 int _max_block_id; // the highest block_id of a block |
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466 int _num_blocks; // total number of blocks (smaller than _max_block_id) |
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467 int _num_loops; // total number of loops |
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468 bool _iterative_dominators;// method requires iterative computation of dominatiors |
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469 |
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470 BlockList* _linear_scan_order; // the resulting list of blocks in correct order |
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471 |
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472 BitMap _visited_blocks; // used for recursive processing of blocks |
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473 BitMap _active_blocks; // used for recursive processing of blocks |
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474 BitMap _dominator_blocks; // temproary BitMap used for computation of dominator |
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475 intArray _forward_branches; // number of incoming forward branches for each block |
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476 BlockList _loop_end_blocks; // list of all loop end blocks collected during count_edges |
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477 BitMap2D _loop_map; // two-dimensional bit set: a bit is set if a block is contained in a loop |
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478 BlockList _work_list; // temporary list (used in mark_loops and compute_order) |
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479 |
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480 // accessors for _visited_blocks and _active_blocks |
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481 void init_visited() { _active_blocks.clear(); _visited_blocks.clear(); } |
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482 bool is_visited(BlockBegin* b) const { return _visited_blocks.at(b->block_id()); } |
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483 bool is_active(BlockBegin* b) const { return _active_blocks.at(b->block_id()); } |
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484 void set_visited(BlockBegin* b) { assert(!is_visited(b), "already set"); _visited_blocks.set_bit(b->block_id()); } |
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485 void set_active(BlockBegin* b) { assert(!is_active(b), "already set"); _active_blocks.set_bit(b->block_id()); } |
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486 void clear_active(BlockBegin* b) { assert(is_active(b), "not already"); _active_blocks.clear_bit(b->block_id()); } |
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487 |
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488 // accessors for _forward_branches |
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489 void inc_forward_branches(BlockBegin* b) { _forward_branches.at_put(b->block_id(), _forward_branches.at(b->block_id()) + 1); } |
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490 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()); } |
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491 |
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492 // accessors for _loop_map |
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493 bool is_block_in_loop (int loop_idx, BlockBegin* b) const { return _loop_map.at(loop_idx, b->block_id()); } |
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494 void set_block_in_loop (int loop_idx, BlockBegin* b) { _loop_map.set_bit(loop_idx, b->block_id()); } |
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495 void clear_block_in_loop(int loop_idx, int block_id) { _loop_map.clear_bit(loop_idx, block_id); } |
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496 |
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497 // count edges between blocks |
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498 void count_edges(BlockBegin* cur, BlockBegin* parent); |
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499 |
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500 // loop detection |
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501 void mark_loops(); |
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502 void clear_non_natural_loops(BlockBegin* start_block); |
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503 void assign_loop_depth(BlockBegin* start_block); |
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504 |
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505 // computation of final block order |
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506 BlockBegin* common_dominator(BlockBegin* a, BlockBegin* b); |
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507 void compute_dominator(BlockBegin* cur, BlockBegin* parent); |
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508 int compute_weight(BlockBegin* cur); |
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509 bool ready_for_processing(BlockBegin* cur); |
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510 void sort_into_work_list(BlockBegin* b); |
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511 void append_block(BlockBegin* cur); |
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512 void compute_order(BlockBegin* start_block); |
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513 |
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514 // fixup of dominators for non-natural loops |
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515 bool compute_dominators_iter(); |
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516 void compute_dominators(); |
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517 |
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518 // debug functions |
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519 NOT_PRODUCT(void print_blocks();) |
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520 DEBUG_ONLY(void verify();) |
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521 |
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522 public: |
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523 ComputeLinearScanOrder(BlockBegin* start_block); |
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524 |
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525 // accessors for final result |
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526 BlockList* linear_scan_order() const { return _linear_scan_order; } |
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527 int num_loops() const { return _num_loops; } |
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528 }; |
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529 |
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530 |
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531 ComputeLinearScanOrder::ComputeLinearScanOrder(BlockBegin* start_block) : |
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532 _max_block_id(BlockBegin::number_of_blocks()), |
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533 _num_blocks(0), |
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534 _num_loops(0), |
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535 _iterative_dominators(false), |
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536 _visited_blocks(_max_block_id), |
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537 _active_blocks(_max_block_id), |
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538 _dominator_blocks(_max_block_id), |
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539 _forward_branches(_max_block_id, 0), |
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540 _loop_end_blocks(8), |
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541 _work_list(8), |
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542 _linear_scan_order(NULL), // initialized later with correct size |
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543 _loop_map(0, 0) // initialized later with correct size |
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544 { |
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545 TRACE_LINEAR_SCAN(2, "***** computing linear-scan block order"); |
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546 |
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547 init_visited(); |
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548 count_edges(start_block, NULL); |
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549 |
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550 if (_num_loops > 0) { |
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551 mark_loops(); |
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552 clear_non_natural_loops(start_block); |
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553 assign_loop_depth(start_block); |
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554 } |
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555 |
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556 compute_order(start_block); |
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557 compute_dominators(); |
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558 |
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559 NOT_PRODUCT(print_blocks()); |
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560 DEBUG_ONLY(verify()); |
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561 } |
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562 |
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563 |
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564 // Traverse the CFG: |
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565 // * count total number of blocks |
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566 // * count all incoming edges and backward incoming edges |
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567 // * number loop header blocks |
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568 // * create a list with all loop end blocks |
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569 void ComputeLinearScanOrder::count_edges(BlockBegin* cur, BlockBegin* parent) { |
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570 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)); |
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571 assert(cur->dominator() == NULL, "dominator already initialized"); |
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572 |
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573 if (is_active(cur)) { |
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574 TRACE_LINEAR_SCAN(3, tty->print_cr("backward branch")); |
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575 assert(is_visited(cur), "block must be visisted when block is active"); |
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576 assert(parent != NULL, "must have parent"); |
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577 assert(parent->number_of_sux() == 1, "loop end blocks must have one successor (critical edges are split)"); |
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578 |
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579 cur->set(BlockBegin::linear_scan_loop_header_flag); |
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580 cur->set(BlockBegin::backward_branch_target_flag); |
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581 |
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582 parent->set(BlockBegin::linear_scan_loop_end_flag); |
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583 _loop_end_blocks.append(parent); |
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584 return; |
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585 } |
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586 |
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587 // increment number of incoming forward branches |
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588 inc_forward_branches(cur); |
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589 |
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590 if (is_visited(cur)) { |
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591 TRACE_LINEAR_SCAN(3, tty->print_cr("block already visited")); |
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592 return; |
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593 } |
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594 |
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595 _num_blocks++; |
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596 set_visited(cur); |
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597 set_active(cur); |
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598 |
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599 // recursive call for all successors |
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600 int i; |
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601 for (i = cur->number_of_sux() - 1; i >= 0; i--) { |
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602 count_edges(cur->sux_at(i), cur); |
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603 } |
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604 for (i = cur->number_of_exception_handlers() - 1; i >= 0; i--) { |
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605 count_edges(cur->exception_handler_at(i), cur); |
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606 } |
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607 |
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608 clear_active(cur); |
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609 |
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610 // Each loop has a unique number. |
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611 // When multiple loops are nested, assign_loop_depth assumes that the |
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612 // innermost loop has the lowest number. This is guaranteed by setting |
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613 // the loop number after the recursive calls for the successors above |
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614 // have returned. |
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615 if (cur->is_set(BlockBegin::linear_scan_loop_header_flag)) { |
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616 assert(cur->loop_index() == -1, "cannot set loop-index twice"); |
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617 TRACE_LINEAR_SCAN(3, tty->print_cr("Block B%d is loop header of loop %d", cur->block_id(), _num_loops)); |
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618 |
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619 cur->set_loop_index(_num_loops); |
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620 _num_loops++; |
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621 } |
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622 |
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623 TRACE_LINEAR_SCAN(3, tty->print_cr("Finished count_edges for block B%d", cur->block_id())); |
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624 } |
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625 |
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626 |
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627 void ComputeLinearScanOrder::mark_loops() { |
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628 TRACE_LINEAR_SCAN(3, tty->print_cr("----- marking loops")); |
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629 |
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630 _loop_map = BitMap2D(_num_loops, _max_block_id); |
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631 _loop_map.clear(); |
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632 |
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633 for (int i = _loop_end_blocks.length() - 1; i >= 0; i--) { |
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634 BlockBegin* loop_end = _loop_end_blocks.at(i); |
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635 BlockBegin* loop_start = loop_end->sux_at(0); |
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636 int loop_idx = loop_start->loop_index(); |
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637 |
|
638 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)); |
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639 assert(loop_end->is_set(BlockBegin::linear_scan_loop_end_flag), "loop end flag must be set"); |
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640 assert(loop_end->number_of_sux() == 1, "incorrect number of successors"); |
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641 assert(loop_start->is_set(BlockBegin::linear_scan_loop_header_flag), "loop header flag must be set"); |
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642 assert(loop_idx >= 0 && loop_idx < _num_loops, "loop index not set"); |
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643 assert(_work_list.is_empty(), "work list must be empty before processing"); |
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644 |
|
645 // add the end-block of the loop to the working list |
|
646 _work_list.push(loop_end); |
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647 set_block_in_loop(loop_idx, loop_end); |
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648 do { |
|
649 BlockBegin* cur = _work_list.pop(); |
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650 |
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651 TRACE_LINEAR_SCAN(3, tty->print_cr(" processing B%d", cur->block_id())); |
|
652 assert(is_block_in_loop(loop_idx, cur), "bit in loop map must be set when block is in work list"); |
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653 |
|
654 // recursive processing of all predecessors ends when start block of loop is reached |
|
655 if (cur != loop_start && !cur->is_set(BlockBegin::osr_entry_flag)) { |
|
656 for (int j = cur->number_of_preds() - 1; j >= 0; j--) { |
|
657 BlockBegin* pred = cur->pred_at(j); |
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658 |
|
659 if (!is_block_in_loop(loop_idx, pred) /*&& !pred->is_set(BlockBeginosr_entry_flag)*/) { |
|
660 // this predecessor has not been processed yet, so add it to work list |
|
661 TRACE_LINEAR_SCAN(3, tty->print_cr(" pushing B%d", pred->block_id())); |
|
662 _work_list.push(pred); |
|
663 set_block_in_loop(loop_idx, pred); |
|
664 } |
|
665 } |
|
666 } |
|
667 } while (!_work_list.is_empty()); |
|
668 } |
|
669 } |
|
670 |
|
671 |
|
672 // check for non-natural loops (loops where the loop header does not dominate |
|
673 // all other loop blocks = loops with mulitple entries). |
|
674 // such loops are ignored |
|
675 void ComputeLinearScanOrder::clear_non_natural_loops(BlockBegin* start_block) { |
|
676 for (int i = _num_loops - 1; i >= 0; i--) { |
|
677 if (is_block_in_loop(i, start_block)) { |
|
678 // loop i contains the entry block of the method |
|
679 // -> this is not a natural loop, so ignore it |
|
680 TRACE_LINEAR_SCAN(2, tty->print_cr("Loop %d is non-natural, so it is ignored", i)); |
|
681 |
|
682 for (int block_id = _max_block_id - 1; block_id >= 0; block_id--) { |
|
683 clear_block_in_loop(i, block_id); |
|
684 } |
|
685 _iterative_dominators = true; |
|
686 } |
|
687 } |
|
688 } |
|
689 |
|
690 void ComputeLinearScanOrder::assign_loop_depth(BlockBegin* start_block) { |
|
691 TRACE_LINEAR_SCAN(3, "----- computing loop-depth and weight"); |
|
692 init_visited(); |
|
693 |
|
694 assert(_work_list.is_empty(), "work list must be empty before processing"); |
|
695 _work_list.append(start_block); |
|
696 |
|
697 do { |
|
698 BlockBegin* cur = _work_list.pop(); |
|
699 |
|
700 if (!is_visited(cur)) { |
|
701 set_visited(cur); |
|
702 TRACE_LINEAR_SCAN(4, tty->print_cr("Computing loop depth for block B%d", cur->block_id())); |
|
703 |
|
704 // compute loop-depth and loop-index for the block |
|
705 assert(cur->loop_depth() == 0, "cannot set loop-depth twice"); |
|
706 int i; |
|
707 int loop_depth = 0; |
|
708 int min_loop_idx = -1; |
|
709 for (i = _num_loops - 1; i >= 0; i--) { |
|
710 if (is_block_in_loop(i, cur)) { |
|
711 loop_depth++; |
|
712 min_loop_idx = i; |
|
713 } |
|
714 } |
|
715 cur->set_loop_depth(loop_depth); |
|
716 cur->set_loop_index(min_loop_idx); |
|
717 |
|
718 // append all unvisited successors to work list |
|
719 for (i = cur->number_of_sux() - 1; i >= 0; i--) { |
|
720 _work_list.append(cur->sux_at(i)); |
|
721 } |
|
722 for (i = cur->number_of_exception_handlers() - 1; i >= 0; i--) { |
|
723 _work_list.append(cur->exception_handler_at(i)); |
|
724 } |
|
725 } |
|
726 } while (!_work_list.is_empty()); |
|
727 } |
|
728 |
|
729 |
|
730 BlockBegin* ComputeLinearScanOrder::common_dominator(BlockBegin* a, BlockBegin* b) { |
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731 assert(a != NULL && b != NULL, "must have input blocks"); |
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732 |
|
733 _dominator_blocks.clear(); |
|
734 while (a != NULL) { |
|
735 _dominator_blocks.set_bit(a->block_id()); |
|
736 assert(a->dominator() != NULL || a == _linear_scan_order->at(0), "dominator must be initialized"); |
|
737 a = a->dominator(); |
|
738 } |
|
739 while (b != NULL && !_dominator_blocks.at(b->block_id())) { |
|
740 assert(b->dominator() != NULL || b == _linear_scan_order->at(0), "dominator must be initialized"); |
|
741 b = b->dominator(); |
|
742 } |
|
743 |
|
744 assert(b != NULL, "could not find dominator"); |
|
745 return b; |
|
746 } |
|
747 |
|
748 void ComputeLinearScanOrder::compute_dominator(BlockBegin* cur, BlockBegin* parent) { |
|
749 if (cur->dominator() == NULL) { |
|
750 TRACE_LINEAR_SCAN(4, tty->print_cr("DOM: initializing dominator of B%d to B%d", cur->block_id(), parent->block_id())); |
|
751 cur->set_dominator(parent); |
|
752 |
|
753 } else if (!(cur->is_set(BlockBegin::linear_scan_loop_header_flag) && parent->is_set(BlockBegin::linear_scan_loop_end_flag))) { |
|
754 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())); |
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755 assert(cur->number_of_preds() > 1, ""); |
|
756 cur->set_dominator(common_dominator(cur->dominator(), parent)); |
|
757 } |
|
758 } |
|
759 |
|
760 |
|
761 int ComputeLinearScanOrder::compute_weight(BlockBegin* cur) { |
|
762 BlockBegin* single_sux = NULL; |
|
763 if (cur->number_of_sux() == 1) { |
|
764 single_sux = cur->sux_at(0); |
|
765 } |
|
766 |
|
767 // limit loop-depth to 15 bit (only for security reason, it will never be so big) |
|
768 int weight = (cur->loop_depth() & 0x7FFF) << 16; |
|
769 |
|
770 // general macro for short definition of weight flags |
|
771 // the first instance of INC_WEIGHT_IF has the highest priority |
|
772 int cur_bit = 15; |
|
773 #define INC_WEIGHT_IF(condition) if ((condition)) { weight |= (1 << cur_bit); } cur_bit--; |
|
774 |
|
775 // this is necessery for the (very rare) case that two successing blocks have |
|
776 // the same loop depth, but a different loop index (can happen for endless loops |
|
777 // with exception handlers) |
|
778 INC_WEIGHT_IF(!cur->is_set(BlockBegin::linear_scan_loop_header_flag)); |
|
779 |
|
780 // loop end blocks (blocks that end with a backward branch) are added |
|
781 // after all other blocks of the loop. |
|
782 INC_WEIGHT_IF(!cur->is_set(BlockBegin::linear_scan_loop_end_flag)); |
|
783 |
|
784 // critical edge split blocks are prefered because than they have a bigger |
|
785 // proability to be completely empty |
|
786 INC_WEIGHT_IF(cur->is_set(BlockBegin::critical_edge_split_flag)); |
|
787 |
|
788 // exceptions should not be thrown in normal control flow, so these blocks |
|
789 // are added as late as possible |
|
790 INC_WEIGHT_IF(cur->end()->as_Throw() == NULL && (single_sux == NULL || single_sux->end()->as_Throw() == NULL)); |
|
791 INC_WEIGHT_IF(cur->end()->as_Return() == NULL && (single_sux == NULL || single_sux->end()->as_Return() == NULL)); |
|
792 |
|
793 // exceptions handlers are added as late as possible |
|
794 INC_WEIGHT_IF(!cur->is_set(BlockBegin::exception_entry_flag)); |
|
795 |
|
796 // guarantee that weight is > 0 |
|
797 weight |= 1; |
|
798 |
|
799 #undef INC_WEIGHT_IF |
|
800 assert(cur_bit >= 0, "too many flags"); |
|
801 assert(weight > 0, "weight cannot become negative"); |
|
802 |
|
803 return weight; |
|
804 } |
|
805 |
|
806 bool ComputeLinearScanOrder::ready_for_processing(BlockBegin* cur) { |
|
807 // Discount the edge just traveled. |
|
808 // When the number drops to zero, all forward branches were processed |
|
809 if (dec_forward_branches(cur) != 0) { |
|
810 return false; |
|
811 } |
|
812 |
|
813 assert(_linear_scan_order->index_of(cur) == -1, "block already processed (block can be ready only once)"); |
|
814 assert(_work_list.index_of(cur) == -1, "block already in work-list (block can be ready only once)"); |
|
815 return true; |
|
816 } |
|
817 |
|
818 void ComputeLinearScanOrder::sort_into_work_list(BlockBegin* cur) { |
|
819 assert(_work_list.index_of(cur) == -1, "block already in work list"); |
|
820 |
|
821 int cur_weight = compute_weight(cur); |
|
822 |
|
823 // the linear_scan_number is used to cache the weight of a block |
|
824 cur->set_linear_scan_number(cur_weight); |
|
825 |
|
826 #ifndef PRODUCT |
|
827 if (StressLinearScan) { |
|
828 _work_list.insert_before(0, cur); |
|
829 return; |
|
830 } |
|
831 #endif |
|
832 |
|
833 _work_list.append(NULL); // provide space for new element |
|
834 |
|
835 int insert_idx = _work_list.length() - 1; |
|
836 while (insert_idx > 0 && _work_list.at(insert_idx - 1)->linear_scan_number() > cur_weight) { |
|
837 _work_list.at_put(insert_idx, _work_list.at(insert_idx - 1)); |
|
838 insert_idx--; |
|
839 } |
|
840 _work_list.at_put(insert_idx, cur); |
|
841 |
|
842 TRACE_LINEAR_SCAN(3, tty->print_cr("Sorted B%d into worklist. new worklist:", cur->block_id())); |
|
843 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())); |
|
844 |
|
845 #ifdef ASSERT |
|
846 for (int i = 0; i < _work_list.length(); i++) { |
|
847 assert(_work_list.at(i)->linear_scan_number() > 0, "weight not set"); |
|
848 assert(i == 0 || _work_list.at(i - 1)->linear_scan_number() <= _work_list.at(i)->linear_scan_number(), "incorrect order in worklist"); |
|
849 } |
|
850 #endif |
|
851 } |
|
852 |
|
853 void ComputeLinearScanOrder::append_block(BlockBegin* cur) { |
|
854 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())); |
|
855 assert(_linear_scan_order->index_of(cur) == -1, "cannot add the same block twice"); |
|
856 |
|
857 // currently, the linear scan order and code emit order are equal. |
|
858 // therefore the linear_scan_number and the weight of a block must also |
|
859 // be equal. |
|
860 cur->set_linear_scan_number(_linear_scan_order->length()); |
|
861 _linear_scan_order->append(cur); |
|
862 } |
|
863 |
|
864 void ComputeLinearScanOrder::compute_order(BlockBegin* start_block) { |
|
865 TRACE_LINEAR_SCAN(3, "----- computing final block order"); |
|
866 |
|
867 // the start block is always the first block in the linear scan order |
|
868 _linear_scan_order = new BlockList(_num_blocks); |
|
869 append_block(start_block); |
|
870 |
|
871 assert(start_block->end()->as_Base() != NULL, "start block must end with Base-instruction"); |
|
872 BlockBegin* std_entry = ((Base*)start_block->end())->std_entry(); |
|
873 BlockBegin* osr_entry = ((Base*)start_block->end())->osr_entry(); |
|
874 |
|
875 BlockBegin* sux_of_osr_entry = NULL; |
|
876 if (osr_entry != NULL) { |
|
877 // special handling for osr entry: |
|
878 // ignore the edge between the osr entry and its successor for processing |
|
879 // the osr entry block is added manually below |
|
880 assert(osr_entry->number_of_sux() == 1, "osr entry must have exactly one successor"); |
|
881 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"); |
|
882 |
|
883 sux_of_osr_entry = osr_entry->sux_at(0); |
|
884 dec_forward_branches(sux_of_osr_entry); |
|
885 |
|
886 compute_dominator(osr_entry, start_block); |
|
887 _iterative_dominators = true; |
|
888 } |
|
889 compute_dominator(std_entry, start_block); |
|
890 |
|
891 // start processing with standard entry block |
|
892 assert(_work_list.is_empty(), "list must be empty before processing"); |
|
893 |
|
894 if (ready_for_processing(std_entry)) { |
|
895 sort_into_work_list(std_entry); |
|
896 } else { |
|
897 assert(false, "the std_entry must be ready for processing (otherwise, the method has no start block)"); |
|
898 } |
|
899 |
|
900 do { |
|
901 BlockBegin* cur = _work_list.pop(); |
|
902 |
|
903 if (cur == sux_of_osr_entry) { |
|
904 // the osr entry block is ignored in normal processing, it is never added to the |
|
905 // work list. Instead, it is added as late as possible manually here. |
|
906 append_block(osr_entry); |
|
907 compute_dominator(cur, osr_entry); |
|
908 } |
|
909 append_block(cur); |
|
910 |
|
911 int i; |
|
912 int num_sux = cur->number_of_sux(); |
|
913 // changed loop order to get "intuitive" order of if- and else-blocks |
|
914 for (i = 0; i < num_sux; i++) { |
|
915 BlockBegin* sux = cur->sux_at(i); |
|
916 compute_dominator(sux, cur); |
|
917 if (ready_for_processing(sux)) { |
|
918 sort_into_work_list(sux); |
|
919 } |
|
920 } |
|
921 num_sux = cur->number_of_exception_handlers(); |
|
922 for (i = 0; i < num_sux; i++) { |
|
923 BlockBegin* sux = cur->exception_handler_at(i); |
|
924 compute_dominator(sux, cur); |
|
925 if (ready_for_processing(sux)) { |
|
926 sort_into_work_list(sux); |
|
927 } |
|
928 } |
|
929 } while (_work_list.length() > 0); |
|
930 } |
|
931 |
|
932 |
|
933 bool ComputeLinearScanOrder::compute_dominators_iter() { |
|
934 bool changed = false; |
|
935 int num_blocks = _linear_scan_order->length(); |
|
936 |
|
937 assert(_linear_scan_order->at(0)->dominator() == NULL, "must not have dominator"); |
|
938 assert(_linear_scan_order->at(0)->number_of_preds() == 0, "must not have predecessors"); |
|
939 for (int i = 1; i < num_blocks; i++) { |
|
940 BlockBegin* block = _linear_scan_order->at(i); |
|
941 |
|
942 BlockBegin* dominator = block->pred_at(0); |
|
943 int num_preds = block->number_of_preds(); |
|
944 for (int i = 1; i < num_preds; i++) { |
|
945 dominator = common_dominator(dominator, block->pred_at(i)); |
|
946 } |
|
947 |
|
948 if (dominator != block->dominator()) { |
|
949 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())); |
|
950 |
|
951 block->set_dominator(dominator); |
|
952 changed = true; |
|
953 } |
|
954 } |
|
955 return changed; |
|
956 } |
|
957 |
|
958 void ComputeLinearScanOrder::compute_dominators() { |
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959 TRACE_LINEAR_SCAN(3, tty->print_cr("----- computing dominators (iterative computation reqired: %d)", _iterative_dominators)); |
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960 |
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961 // iterative computation of dominators is only required for methods with non-natural loops |
|
962 // and OSR-methods. For all other methods, the dominators computed when generating the |
|
963 // linear scan block order are correct. |
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964 if (_iterative_dominators) { |
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965 do { |
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966 TRACE_LINEAR_SCAN(1, tty->print_cr("DOM: next iteration of fix-point calculation")); |
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967 } while (compute_dominators_iter()); |
|
968 } |
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969 |
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970 // check that dominators are correct |
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971 assert(!compute_dominators_iter(), "fix point not reached"); |
|
972 } |
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973 |
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974 |
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975 #ifndef PRODUCT |
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976 void ComputeLinearScanOrder::print_blocks() { |
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977 if (TraceLinearScanLevel >= 2) { |
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978 tty->print_cr("----- loop information:"); |
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979 for (int block_idx = 0; block_idx < _linear_scan_order->length(); block_idx++) { |
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980 BlockBegin* cur = _linear_scan_order->at(block_idx); |
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981 |
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982 tty->print("%4d: B%2d: ", cur->linear_scan_number(), cur->block_id()); |
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983 for (int loop_idx = 0; loop_idx < _num_loops; loop_idx++) { |
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984 tty->print ("%d ", is_block_in_loop(loop_idx, cur)); |
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985 } |
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986 tty->print_cr(" -> loop_index: %2d, loop_depth: %2d", cur->loop_index(), cur->loop_depth()); |
|
987 } |
|
988 } |
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989 |
|
990 if (TraceLinearScanLevel >= 1) { |
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991 tty->print_cr("----- linear-scan block order:"); |
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992 for (int block_idx = 0; block_idx < _linear_scan_order->length(); block_idx++) { |
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993 BlockBegin* cur = _linear_scan_order->at(block_idx); |
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994 tty->print("%4d: B%2d loop: %2d depth: %2d", cur->linear_scan_number(), cur->block_id(), cur->loop_index(), cur->loop_depth()); |
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995 |
|
996 tty->print(cur->is_set(BlockBegin::exception_entry_flag) ? " ex" : " "); |
|
997 tty->print(cur->is_set(BlockBegin::critical_edge_split_flag) ? " ce" : " "); |
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998 tty->print(cur->is_set(BlockBegin::linear_scan_loop_header_flag) ? " lh" : " "); |
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999 tty->print(cur->is_set(BlockBegin::linear_scan_loop_end_flag) ? " le" : " "); |
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1000 |
|
1001 if (cur->dominator() != NULL) { |
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1002 tty->print(" dom: B%d ", cur->dominator()->block_id()); |
|
1003 } else { |
|
1004 tty->print(" dom: NULL "); |
|
1005 } |
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1006 |
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1007 if (cur->number_of_preds() > 0) { |
|
1008 tty->print(" preds: "); |
|
1009 for (int j = 0; j < cur->number_of_preds(); j++) { |
|
1010 BlockBegin* pred = cur->pred_at(j); |
|
1011 tty->print("B%d ", pred->block_id()); |
|
1012 } |
|
1013 } |
|
1014 if (cur->number_of_sux() > 0) { |
|
1015 tty->print(" sux: "); |
|
1016 for (int j = 0; j < cur->number_of_sux(); j++) { |
|
1017 BlockBegin* sux = cur->sux_at(j); |
|
1018 tty->print("B%d ", sux->block_id()); |
|
1019 } |
|
1020 } |
|
1021 if (cur->number_of_exception_handlers() > 0) { |
|
1022 tty->print(" ex: "); |
|
1023 for (int j = 0; j < cur->number_of_exception_handlers(); j++) { |
|
1024 BlockBegin* ex = cur->exception_handler_at(j); |
|
1025 tty->print("B%d ", ex->block_id()); |
|
1026 } |
|
1027 } |
|
1028 tty->cr(); |
|
1029 } |
|
1030 } |
|
1031 } |
|
1032 #endif |
|
1033 |
|
1034 #ifdef ASSERT |
|
1035 void ComputeLinearScanOrder::verify() { |
|
1036 assert(_linear_scan_order->length() == _num_blocks, "wrong number of blocks in list"); |
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1037 |
|
1038 if (StressLinearScan) { |
|
1039 // blocks are scrambled when StressLinearScan is used |
|
1040 return; |
|
1041 } |
|
1042 |
|
1043 // check that all successors of a block have a higher linear-scan-number |
|
1044 // and that all predecessors of a block have a lower linear-scan-number |
|
1045 // (only backward branches of loops are ignored) |
|
1046 int i; |
|
1047 for (i = 0; i < _linear_scan_order->length(); i++) { |
|
1048 BlockBegin* cur = _linear_scan_order->at(i); |
|
1049 |
|
1050 assert(cur->linear_scan_number() == i, "incorrect linear_scan_number"); |
|
1051 assert(cur->linear_scan_number() >= 0 && cur->linear_scan_number() == _linear_scan_order->index_of(cur), "incorrect linear_scan_number"); |
|
1052 |
|
1053 int j; |
|
1054 for (j = cur->number_of_sux() - 1; j >= 0; j--) { |
|
1055 BlockBegin* sux = cur->sux_at(j); |
|
1056 |
|
1057 assert(sux->linear_scan_number() >= 0 && sux->linear_scan_number() == _linear_scan_order->index_of(sux), "incorrect linear_scan_number"); |
|
1058 if (!cur->is_set(BlockBegin::linear_scan_loop_end_flag)) { |
|
1059 assert(cur->linear_scan_number() < sux->linear_scan_number(), "invalid order"); |
|
1060 } |
|
1061 if (cur->loop_depth() == sux->loop_depth()) { |
|
1062 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"); |
|
1063 } |
|
1064 } |
|
1065 |
|
1066 for (j = cur->number_of_preds() - 1; j >= 0; j--) { |
|
1067 BlockBegin* pred = cur->pred_at(j); |
|
1068 |
|
1069 assert(pred->linear_scan_number() >= 0 && pred->linear_scan_number() == _linear_scan_order->index_of(pred), "incorrect linear_scan_number"); |
|
1070 if (!cur->is_set(BlockBegin::linear_scan_loop_header_flag)) { |
|
1071 assert(cur->linear_scan_number() > pred->linear_scan_number(), "invalid order"); |
|
1072 } |
|
1073 if (cur->loop_depth() == pred->loop_depth()) { |
|
1074 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"); |
|
1075 } |
|
1076 |
|
1077 assert(cur->dominator()->linear_scan_number() <= cur->pred_at(j)->linear_scan_number(), "dominator must be before predecessors"); |
|
1078 } |
|
1079 |
|
1080 // check dominator |
|
1081 if (i == 0) { |
|
1082 assert(cur->dominator() == NULL, "first block has no dominator"); |
|
1083 } else { |
|
1084 assert(cur->dominator() != NULL, "all but first block must have dominator"); |
|
1085 } |
|
1086 assert(cur->number_of_preds() != 1 || cur->dominator() == cur->pred_at(0), "Single predecessor must also be dominator"); |
|
1087 } |
|
1088 |
|
1089 // check that all loops are continuous |
|
1090 for (int loop_idx = 0; loop_idx < _num_loops; loop_idx++) { |
|
1091 int block_idx = 0; |
|
1092 assert(!is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx)), "the first block must not be present in any loop"); |
|
1093 |
|
1094 // skip blocks before the loop |
|
1095 while (block_idx < _num_blocks && !is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx))) { |
|
1096 block_idx++; |
|
1097 } |
|
1098 // skip blocks of loop |
|
1099 while (block_idx < _num_blocks && is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx))) { |
|
1100 block_idx++; |
|
1101 } |
|
1102 // after the first non-loop block, there must not be another loop-block |
|
1103 while (block_idx < _num_blocks) { |
|
1104 assert(!is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx)), "loop not continuous in linear-scan order"); |
|
1105 block_idx++; |
|
1106 } |
|
1107 } |
|
1108 } |
|
1109 #endif |
|
1110 |
|
1111 |
|
1112 void IR::compute_code() { |
|
1113 assert(is_valid(), "IR must be valid"); |
|
1114 |
|
1115 ComputeLinearScanOrder compute_order(start()); |
|
1116 _num_loops = compute_order.num_loops(); |
|
1117 _code = compute_order.linear_scan_order(); |
|
1118 } |
|
1119 |
|
1120 |
|
1121 void IR::compute_use_counts() { |
|
1122 // make sure all values coming out of this block get evaluated. |
|
1123 int num_blocks = _code->length(); |
|
1124 for (int i = 0; i < num_blocks; i++) { |
|
1125 _code->at(i)->end()->state()->pin_stack_for_linear_scan(); |
|
1126 } |
|
1127 |
|
1128 // compute use counts |
|
1129 UseCountComputer::compute(_code); |
|
1130 } |
|
1131 |
|
1132 |
|
1133 void IR::iterate_preorder(BlockClosure* closure) { |
|
1134 assert(is_valid(), "IR must be valid"); |
|
1135 start()->iterate_preorder(closure); |
|
1136 } |
|
1137 |
|
1138 |
|
1139 void IR::iterate_postorder(BlockClosure* closure) { |
|
1140 assert(is_valid(), "IR must be valid"); |
|
1141 start()->iterate_postorder(closure); |
|
1142 } |
|
1143 |
|
1144 void IR::iterate_linear_scan_order(BlockClosure* closure) { |
|
1145 linear_scan_order()->iterate_forward(closure); |
|
1146 } |
|
1147 |
|
1148 |
|
1149 #ifndef PRODUCT |
|
1150 class BlockPrinter: public BlockClosure { |
|
1151 private: |
|
1152 InstructionPrinter* _ip; |
|
1153 bool _cfg_only; |
|
1154 bool _live_only; |
|
1155 |
|
1156 public: |
|
1157 BlockPrinter(InstructionPrinter* ip, bool cfg_only, bool live_only = false) { |
|
1158 _ip = ip; |
|
1159 _cfg_only = cfg_only; |
|
1160 _live_only = live_only; |
|
1161 } |
|
1162 |
|
1163 virtual void block_do(BlockBegin* block) { |
|
1164 if (_cfg_only) { |
|
1165 _ip->print_instr(block); tty->cr(); |
|
1166 } else { |
|
1167 block->print_block(*_ip, _live_only); |
|
1168 } |
|
1169 } |
|
1170 }; |
|
1171 |
|
1172 |
|
1173 void IR::print(BlockBegin* start, bool cfg_only, bool live_only) { |
|
1174 ttyLocker ttyl; |
|
1175 InstructionPrinter ip(!cfg_only); |
|
1176 BlockPrinter bp(&ip, cfg_only, live_only); |
|
1177 start->iterate_preorder(&bp); |
|
1178 tty->cr(); |
|
1179 } |
|
1180 |
|
1181 void IR::print(bool cfg_only, bool live_only) { |
|
1182 if (is_valid()) { |
|
1183 print(start(), cfg_only, live_only); |
|
1184 } else { |
|
1185 tty->print_cr("invalid IR"); |
|
1186 } |
|
1187 } |
|
1188 |
|
1189 |
|
1190 define_array(BlockListArray, BlockList*) |
|
1191 define_stack(BlockListList, BlockListArray) |
|
1192 |
|
1193 class PredecessorValidator : public BlockClosure { |
|
1194 private: |
|
1195 BlockListList* _predecessors; |
|
1196 BlockList* _blocks; |
|
1197 |
|
1198 static int cmp(BlockBegin** a, BlockBegin** b) { |
|
1199 return (*a)->block_id() - (*b)->block_id(); |
|
1200 } |
|
1201 |
|
1202 public: |
|
1203 PredecessorValidator(IR* hir) { |
|
1204 ResourceMark rm; |
|
1205 _predecessors = new BlockListList(BlockBegin::number_of_blocks(), NULL); |
|
1206 _blocks = new BlockList(); |
|
1207 |
|
1208 int i; |
|
1209 hir->start()->iterate_preorder(this); |
|
1210 if (hir->code() != NULL) { |
|
1211 assert(hir->code()->length() == _blocks->length(), "must match"); |
|
1212 for (i = 0; i < _blocks->length(); i++) { |
|
1213 assert(hir->code()->contains(_blocks->at(i)), "should be in both lists"); |
|
1214 } |
|
1215 } |
|
1216 |
|
1217 for (i = 0; i < _blocks->length(); i++) { |
|
1218 BlockBegin* block = _blocks->at(i); |
|
1219 BlockList* preds = _predecessors->at(block->block_id()); |
|
1220 if (preds == NULL) { |
|
1221 assert(block->number_of_preds() == 0, "should be the same"); |
|
1222 continue; |
|
1223 } |
|
1224 |
|
1225 // clone the pred list so we can mutate it |
|
1226 BlockList* pred_copy = new BlockList(); |
|
1227 int j; |
|
1228 for (j = 0; j < block->number_of_preds(); j++) { |
|
1229 pred_copy->append(block->pred_at(j)); |
|
1230 } |
|
1231 // sort them in the same order |
|
1232 preds->sort(cmp); |
|
1233 pred_copy->sort(cmp); |
|
1234 int length = MIN2(preds->length(), block->number_of_preds()); |
|
1235 for (j = 0; j < block->number_of_preds(); j++) { |
|
1236 assert(preds->at(j) == pred_copy->at(j), "must match"); |
|
1237 } |
|
1238 |
|
1239 assert(preds->length() == block->number_of_preds(), "should be the same"); |
|
1240 } |
|
1241 } |
|
1242 |
|
1243 virtual void block_do(BlockBegin* block) { |
|
1244 _blocks->append(block); |
|
1245 BlockEnd* be = block->end(); |
|
1246 int n = be->number_of_sux(); |
|
1247 int i; |
|
1248 for (i = 0; i < n; i++) { |
|
1249 BlockBegin* sux = be->sux_at(i); |
|
1250 assert(!sux->is_set(BlockBegin::exception_entry_flag), "must not be xhandler"); |
|
1251 |
|
1252 BlockList* preds = _predecessors->at_grow(sux->block_id(), NULL); |
|
1253 if (preds == NULL) { |
|
1254 preds = new BlockList(); |
|
1255 _predecessors->at_put(sux->block_id(), preds); |
|
1256 } |
|
1257 preds->append(block); |
|
1258 } |
|
1259 |
|
1260 n = block->number_of_exception_handlers(); |
|
1261 for (i = 0; i < n; i++) { |
|
1262 BlockBegin* sux = block->exception_handler_at(i); |
|
1263 assert(sux->is_set(BlockBegin::exception_entry_flag), "must be xhandler"); |
|
1264 |
|
1265 BlockList* preds = _predecessors->at_grow(sux->block_id(), NULL); |
|
1266 if (preds == NULL) { |
|
1267 preds = new BlockList(); |
|
1268 _predecessors->at_put(sux->block_id(), preds); |
|
1269 } |
|
1270 preds->append(block); |
|
1271 } |
|
1272 } |
|
1273 }; |
|
1274 |
|
1275 void IR::verify() { |
|
1276 #ifdef ASSERT |
|
1277 PredecessorValidator pv(this); |
|
1278 #endif |
|
1279 } |
|
1280 |
|
1281 #endif // PRODUCT |
|
1282 |
|
1283 void SubstitutionResolver::substitute(Value* v) { |
|
1284 Value v0 = *v; |
|
1285 if (v0) { |
|
1286 Value vs = v0->subst(); |
|
1287 if (vs != v0) { |
|
1288 *v = v0->subst(); |
|
1289 } |
|
1290 } |
|
1291 } |
|
1292 |
|
1293 #ifdef ASSERT |
|
1294 void check_substitute(Value* v) { |
|
1295 Value v0 = *v; |
|
1296 if (v0) { |
|
1297 Value vs = v0->subst(); |
|
1298 assert(vs == v0, "missed substitution"); |
|
1299 } |
|
1300 } |
|
1301 #endif |
|
1302 |
|
1303 |
|
1304 void SubstitutionResolver::block_do(BlockBegin* block) { |
|
1305 Instruction* last = NULL; |
|
1306 for (Instruction* n = block; n != NULL;) { |
|
1307 n->values_do(substitute); |
|
1308 // need to remove this instruction from the instruction stream |
|
1309 if (n->subst() != n) { |
|
1310 assert(last != NULL, "must have last"); |
|
1311 last->set_next(n->next(), n->next()->bci()); |
|
1312 } else { |
|
1313 last = n; |
|
1314 } |
|
1315 n = last->next(); |
|
1316 } |
|
1317 |
|
1318 #ifdef ASSERT |
|
1319 if (block->state()) block->state()->values_do(check_substitute); |
|
1320 block->block_values_do(check_substitute); |
|
1321 if (block->end() && block->end()->state()) block->end()->state()->values_do(check_substitute); |
|
1322 #endif |
|
1323 } |