0
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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
|
|
474 BitMap _dominator_blocks; // temproary BitMap used for computation of dominator
|
|
475 intArray _forward_branches; // number of incoming forward branches for each block
|
|
476 BlockList _loop_end_blocks; // list of all loop end blocks collected during count_edges
|
|
477 BitMap2D _loop_map; // two-dimensional bit set: a bit is set if a block is contained in a loop
|
|
478 BlockList _work_list; // temporary list (used in mark_loops and compute_order)
|
|
479
|
|
480 // accessors for _visited_blocks and _active_blocks
|
|
481 void init_visited() { _active_blocks.clear(); _visited_blocks.clear(); }
|
|
482 bool is_visited(BlockBegin* b) const { return _visited_blocks.at(b->block_id()); }
|
|
483 bool is_active(BlockBegin* b) const { return _active_blocks.at(b->block_id()); }
|
|
484 void set_visited(BlockBegin* b) { assert(!is_visited(b), "already set"); _visited_blocks.set_bit(b->block_id()); }
|
|
485 void set_active(BlockBegin* b) { assert(!is_active(b), "already set"); _active_blocks.set_bit(b->block_id()); }
|
|
486 void clear_active(BlockBegin* b) { assert(is_active(b), "not already"); _active_blocks.clear_bit(b->block_id()); }
|
|
487
|
|
488 // accessors for _forward_branches
|
|
489 void inc_forward_branches(BlockBegin* b) { _forward_branches.at_put(b->block_id(), _forward_branches.at(b->block_id()) + 1); }
|
|
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()); }
|
|
491
|
|
492 // accessors for _loop_map
|
|
493 bool is_block_in_loop (int loop_idx, BlockBegin* b) const { return _loop_map.at(loop_idx, b->block_id()); }
|
|
494 void set_block_in_loop (int loop_idx, BlockBegin* b) { _loop_map.set_bit(loop_idx, b->block_id()); }
|
|
495 void clear_block_in_loop(int loop_idx, int block_id) { _loop_map.clear_bit(loop_idx, block_id); }
|
|
496
|
|
497 // count edges between blocks
|
|
498 void count_edges(BlockBegin* cur, BlockBegin* parent);
|
|
499
|
|
500 // loop detection
|
|
501 void mark_loops();
|
|
502 void clear_non_natural_loops(BlockBegin* start_block);
|
|
503 void assign_loop_depth(BlockBegin* start_block);
|
|
504
|
|
505 // computation of final block order
|
|
506 BlockBegin* common_dominator(BlockBegin* a, BlockBegin* b);
|
|
507 void compute_dominator(BlockBegin* cur, BlockBegin* parent);
|
|
508 int compute_weight(BlockBegin* cur);
|
|
509 bool ready_for_processing(BlockBegin* cur);
|
|
510 void sort_into_work_list(BlockBegin* b);
|
|
511 void append_block(BlockBegin* cur);
|
|
512 void compute_order(BlockBegin* start_block);
|
|
513
|
|
514 // fixup of dominators for non-natural loops
|
|
515 bool compute_dominators_iter();
|
|
516 void compute_dominators();
|
|
517
|
|
518 // debug functions
|
|
519 NOT_PRODUCT(void print_blocks();)
|
|
520 DEBUG_ONLY(void verify();)
|
|
521
|
|
522 public:
|
|
523 ComputeLinearScanOrder(BlockBegin* start_block);
|
|
524
|
|
525 // accessors for final result
|
|
526 BlockList* linear_scan_order() const { return _linear_scan_order; }
|
|
527 int num_loops() const { return _num_loops; }
|
|
528 };
|
|
529
|
|
530
|
|
531 ComputeLinearScanOrder::ComputeLinearScanOrder(BlockBegin* start_block) :
|
|
532 _max_block_id(BlockBegin::number_of_blocks()),
|
|
533 _num_blocks(0),
|
|
534 _num_loops(0),
|
|
535 _iterative_dominators(false),
|
|
536 _visited_blocks(_max_block_id),
|
|
537 _active_blocks(_max_block_id),
|
|
538 _dominator_blocks(_max_block_id),
|
|
539 _forward_branches(_max_block_id, 0),
|
|
540 _loop_end_blocks(8),
|
|
541 _work_list(8),
|
|
542 _linear_scan_order(NULL), // initialized later with correct size
|
|
543 _loop_map(0, 0) // initialized later with correct size
|
|
544 {
|
|
545 TRACE_LINEAR_SCAN(2, "***** computing linear-scan block order");
|
|
546
|
|
547 init_visited();
|
|
548 count_edges(start_block, NULL);
|
|
549
|
|
550 if (_num_loops > 0) {
|
|
551 mark_loops();
|
|
552 clear_non_natural_loops(start_block);
|
|
553 assign_loop_depth(start_block);
|
|
554 }
|
|
555
|
|
556 compute_order(start_block);
|
|
557 compute_dominators();
|
|
558
|
|
559 NOT_PRODUCT(print_blocks());
|
|
560 DEBUG_ONLY(verify());
|
|
561 }
|
|
562
|
|
563
|
|
564 // Traverse the CFG:
|
|
565 // * count total number of blocks
|
|
566 // * count all incoming edges and backward incoming edges
|
|
567 // * number loop header blocks
|
|
568 // * create a list with all loop end blocks
|
|
569 void ComputeLinearScanOrder::count_edges(BlockBegin* cur, BlockBegin* parent) {
|
|
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));
|
|
571 assert(cur->dominator() == NULL, "dominator already initialized");
|
|
572
|
|
573 if (is_active(cur)) {
|
|
574 TRACE_LINEAR_SCAN(3, tty->print_cr("backward branch"));
|
|
575 assert(is_visited(cur), "block must be visisted when block is active");
|
|
576 assert(parent != NULL, "must have parent");
|
|
577 assert(parent->number_of_sux() == 1, "loop end blocks must have one successor (critical edges are split)");
|
|
578
|
|
579 cur->set(BlockBegin::linear_scan_loop_header_flag);
|
|
580 cur->set(BlockBegin::backward_branch_target_flag);
|
|
581
|
|
582 parent->set(BlockBegin::linear_scan_loop_end_flag);
|
|
583 _loop_end_blocks.append(parent);
|
|
584 return;
|
|
585 }
|
|
586
|
|
587 // increment number of incoming forward branches
|
|
588 inc_forward_branches(cur);
|
|
589
|
|
590 if (is_visited(cur)) {
|
|
591 TRACE_LINEAR_SCAN(3, tty->print_cr("block already visited"));
|
|
592 return;
|
|
593 }
|
|
594
|
|
595 _num_blocks++;
|
|
596 set_visited(cur);
|
|
597 set_active(cur);
|
|
598
|
|
599 // recursive call for all successors
|
|
600 int i;
|
|
601 for (i = cur->number_of_sux() - 1; i >= 0; i--) {
|
|
602 count_edges(cur->sux_at(i), cur);
|
|
603 }
|
|
604 for (i = cur->number_of_exception_handlers() - 1; i >= 0; i--) {
|
|
605 count_edges(cur->exception_handler_at(i), cur);
|
|
606 }
|
|
607
|
|
608 clear_active(cur);
|
|
609
|
|
610 // Each loop has a unique number.
|
|
611 // When multiple loops are nested, assign_loop_depth assumes that the
|
|
612 // innermost loop has the lowest number. This is guaranteed by setting
|
|
613 // the loop number after the recursive calls for the successors above
|
|
614 // have returned.
|
|
615 if (cur->is_set(BlockBegin::linear_scan_loop_header_flag)) {
|
|
616 assert(cur->loop_index() == -1, "cannot set loop-index twice");
|
|
617 TRACE_LINEAR_SCAN(3, tty->print_cr("Block B%d is loop header of loop %d", cur->block_id(), _num_loops));
|
|
618
|
|
619 cur->set_loop_index(_num_loops);
|
|
620 _num_loops++;
|
|
621 }
|
|
622
|
|
623 TRACE_LINEAR_SCAN(3, tty->print_cr("Finished count_edges for block B%d", cur->block_id()));
|
|
624 }
|
|
625
|
|
626
|
|
627 void ComputeLinearScanOrder::mark_loops() {
|
|
628 TRACE_LINEAR_SCAN(3, tty->print_cr("----- marking loops"));
|
|
629
|
|
630 _loop_map = BitMap2D(_num_loops, _max_block_id);
|
|
631 _loop_map.clear();
|
|
632
|
|
633 for (int i = _loop_end_blocks.length() - 1; i >= 0; i--) {
|
|
634 BlockBegin* loop_end = _loop_end_blocks.at(i);
|
|
635 BlockBegin* loop_start = loop_end->sux_at(0);
|
|
636 int loop_idx = loop_start->loop_index();
|
|
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));
|
|
639 assert(loop_end->is_set(BlockBegin::linear_scan_loop_end_flag), "loop end flag must be set");
|
|
640 assert(loop_end->number_of_sux() == 1, "incorrect number of successors");
|
|
641 assert(loop_start->is_set(BlockBegin::linear_scan_loop_header_flag), "loop header flag must be set");
|
|
642 assert(loop_idx >= 0 && loop_idx < _num_loops, "loop index not set");
|
|
643 assert(_work_list.is_empty(), "work list must be empty before processing");
|
|
644
|
|
645 // add the end-block of the loop to the working list
|
|
646 _work_list.push(loop_end);
|
|
647 set_block_in_loop(loop_idx, loop_end);
|
|
648 do {
|
|
649 BlockBegin* cur = _work_list.pop();
|
|
650
|
|
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");
|
|
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);
|
|
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) {
|
|
731 assert(a != NULL && b != NULL, "must have input blocks");
|
|
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()));
|
|
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() {
|
|
959 TRACE_LINEAR_SCAN(3, tty->print_cr("----- computing dominators (iterative computation reqired: %d)", _iterative_dominators));
|
|
960
|
|
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.
|
|
964 if (_iterative_dominators) {
|
|
965 do {
|
|
966 TRACE_LINEAR_SCAN(1, tty->print_cr("DOM: next iteration of fix-point calculation"));
|
|
967 } while (compute_dominators_iter());
|
|
968 }
|
|
969
|
|
970 // check that dominators are correct
|
|
971 assert(!compute_dominators_iter(), "fix point not reached");
|
|
972 }
|
|
973
|
|
974
|
|
975 #ifndef PRODUCT
|
|
976 void ComputeLinearScanOrder::print_blocks() {
|
|
977 if (TraceLinearScanLevel >= 2) {
|
|
978 tty->print_cr("----- loop information:");
|
|
979 for (int block_idx = 0; block_idx < _linear_scan_order->length(); block_idx++) {
|
|
980 BlockBegin* cur = _linear_scan_order->at(block_idx);
|
|
981
|
|
982 tty->print("%4d: B%2d: ", cur->linear_scan_number(), cur->block_id());
|
|
983 for (int loop_idx = 0; loop_idx < _num_loops; loop_idx++) {
|
|
984 tty->print ("%d ", is_block_in_loop(loop_idx, cur));
|
|
985 }
|
|
986 tty->print_cr(" -> loop_index: %2d, loop_depth: %2d", cur->loop_index(), cur->loop_depth());
|
|
987 }
|
|
988 }
|
|
989
|
|
990 if (TraceLinearScanLevel >= 1) {
|
|
991 tty->print_cr("----- linear-scan block order:");
|
|
992 for (int block_idx = 0; block_idx < _linear_scan_order->length(); block_idx++) {
|
|
993 BlockBegin* cur = _linear_scan_order->at(block_idx);
|
|
994 tty->print("%4d: B%2d loop: %2d depth: %2d", cur->linear_scan_number(), cur->block_id(), cur->loop_index(), cur->loop_depth());
|
|
995
|
|
996 tty->print(cur->is_set(BlockBegin::exception_entry_flag) ? " ex" : " ");
|
|
997 tty->print(cur->is_set(BlockBegin::critical_edge_split_flag) ? " ce" : " ");
|
|
998 tty->print(cur->is_set(BlockBegin::linear_scan_loop_header_flag) ? " lh" : " ");
|
|
999 tty->print(cur->is_set(BlockBegin::linear_scan_loop_end_flag) ? " le" : " ");
|
|
1000
|
|
1001 if (cur->dominator() != NULL) {
|
|
1002 tty->print(" dom: B%d ", cur->dominator()->block_id());
|
|
1003 } else {
|
|
1004 tty->print(" dom: NULL ");
|
|
1005 }
|
|
1006
|
|
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");
|
|
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 }
|