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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 class ValueMapEntry: public CompilationResourceObj { |
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26 private: |
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27 intx _hash; |
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28 Value _value; |
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29 int _nesting; |
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30 ValueMapEntry* _next; |
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31 |
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32 public: |
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33 ValueMapEntry(intx hash, Value value, int nesting, ValueMapEntry* next) |
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34 : _hash(hash) |
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35 , _value(value) |
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36 , _nesting(nesting) |
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37 , _next(next) |
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38 { |
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39 } |
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40 |
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41 intx hash() { return _hash; } |
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42 Value value() { return _value; } |
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43 int nesting() { return _nesting; } |
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44 ValueMapEntry* next() { return _next; } |
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45 |
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46 void set_next(ValueMapEntry* next) { _next = next; } |
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47 }; |
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48 |
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49 define_array(ValueMapEntryArray, ValueMapEntry*) |
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50 define_stack(ValueMapEntryList, ValueMapEntryArray) |
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51 |
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52 // ValueMap implements nested hash tables for value numbering. It |
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53 // maintains a set _killed_values which represents the instructions |
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54 // which have been killed so far and an array of linked lists of |
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55 // ValueMapEntries names _entries. Each ValueMapEntry has a nesting |
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56 // which indicates what ValueMap nesting it belongs to. Higher |
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57 // nesting values are always before lower values in the linked list. |
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58 // This allows cloning of parent ValueMaps by simply copying the heads |
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59 // of the list. _entry_count represents the number of reachable |
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60 // entries in the ValueMap. A ValueMap is only allowed to mutate |
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61 // ValueMapEntries with the same nesting level. Adding or removing |
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62 // entries at the current nesting level requires updating |
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63 // _entry_count. Elements in the parent's list that get killed can be |
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64 // skipped if they are at the head of the list by simply moving to the |
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65 // next element in the list and decrementing _entry_count. |
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66 |
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67 class ValueMap: public CompilationResourceObj { |
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68 private: |
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69 int _nesting; |
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70 ValueMapEntryArray _entries; |
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71 ValueSet _killed_values; |
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72 int _entry_count; |
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73 |
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74 int nesting() { return _nesting; } |
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75 bool is_local_value_numbering() { return _nesting == 0; } |
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76 bool is_global_value_numbering() { return _nesting > 0; } |
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77 |
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78 int entry_count() { return _entry_count; } |
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79 int size() { return _entries.length(); } |
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80 ValueMapEntry* entry_at(int i) { return _entries.at(i); } |
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81 |
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82 // calculates the index of a hash value in a hash table of size n |
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83 int entry_index(intx hash, int n) { return (unsigned int)hash % n; } |
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84 |
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85 // if entry_count > size_threshold, the size of the hash table is increased |
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86 int size_threshold() { return size(); } |
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87 |
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88 // management of the killed-bitset for global value numbering |
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89 void kill_value(Value v) { if (is_global_value_numbering()) _killed_values.put(v); } |
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90 bool is_killed(Value v) { if (is_global_value_numbering()) return _killed_values.contains(v); else return false; } |
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91 |
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92 // helper functions |
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93 void increase_table_size(); |
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94 |
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95 #ifndef PRODUCT |
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96 static int _number_of_finds; |
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97 static int _number_of_hits; |
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98 static int _number_of_kills; |
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99 #endif // PRODUCT |
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100 |
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101 public: |
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102 // creation |
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103 ValueMap(); // empty value map |
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104 ValueMap(ValueMap* old); // value map with increased nesting |
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105 |
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106 // manipulation |
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107 Value find_insert(Value x); |
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108 |
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109 void kill_memory(); |
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110 void kill_field(ciField* field); |
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111 void kill_array(ValueType* type); |
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112 void kill_exception(); |
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113 void kill_map(ValueMap* map); |
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114 void kill_all(); |
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115 |
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116 #ifndef PRODUCT |
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117 // debugging/printing |
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118 void print(); |
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119 |
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120 static void reset_statistics(); |
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121 static void print_statistics(); |
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122 #endif |
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123 }; |
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124 |
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125 define_array(ValueMapArray, ValueMap*) |
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126 |
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127 |
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128 class ValueNumberingVisitor: public InstructionVisitor { |
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129 protected: |
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130 // called by visitor functions for instructions that kill values |
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131 virtual void kill_memory() = 0; |
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132 virtual void kill_field(ciField* field) = 0; |
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133 virtual void kill_array(ValueType* type) = 0; |
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134 |
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135 // visitor functions |
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136 void do_StoreField (StoreField* x) { kill_field(x->field()); }; |
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137 void do_StoreIndexed (StoreIndexed* x) { kill_array(x->type()); }; |
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138 void do_MonitorEnter (MonitorEnter* x) { kill_memory(); }; |
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139 void do_MonitorExit (MonitorExit* x) { kill_memory(); }; |
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140 void do_Invoke (Invoke* x) { kill_memory(); }; |
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141 void do_UnsafePutRaw (UnsafePutRaw* x) { kill_memory(); }; |
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142 void do_UnsafePutObject(UnsafePutObject* x) { kill_memory(); }; |
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143 void do_Intrinsic (Intrinsic* x) { if (!x->preserves_state()) kill_memory(); }; |
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144 |
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145 void do_Phi (Phi* x) { /* nothing to do */ }; |
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146 void do_Local (Local* x) { /* nothing to do */ }; |
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147 void do_Constant (Constant* x) { /* nothing to do */ }; |
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148 void do_LoadField (LoadField* x) { /* nothing to do */ }; |
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149 void do_ArrayLength (ArrayLength* x) { /* nothing to do */ }; |
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150 void do_LoadIndexed (LoadIndexed* x) { /* nothing to do */ }; |
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151 void do_NegateOp (NegateOp* x) { /* nothing to do */ }; |
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152 void do_ArithmeticOp (ArithmeticOp* x) { /* nothing to do */ }; |
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153 void do_ShiftOp (ShiftOp* x) { /* nothing to do */ }; |
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154 void do_LogicOp (LogicOp* x) { /* nothing to do */ }; |
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155 void do_CompareOp (CompareOp* x) { /* nothing to do */ }; |
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156 void do_IfOp (IfOp* x) { /* nothing to do */ }; |
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157 void do_Convert (Convert* x) { /* nothing to do */ }; |
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158 void do_NullCheck (NullCheck* x) { /* nothing to do */ }; |
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159 void do_NewInstance (NewInstance* x) { /* nothing to do */ }; |
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160 void do_NewTypeArray (NewTypeArray* x) { /* nothing to do */ }; |
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161 void do_NewObjectArray (NewObjectArray* x) { /* nothing to do */ }; |
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162 void do_NewMultiArray (NewMultiArray* x) { /* nothing to do */ }; |
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163 void do_CheckCast (CheckCast* x) { /* nothing to do */ }; |
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164 void do_InstanceOf (InstanceOf* x) { /* nothing to do */ }; |
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165 void do_BlockBegin (BlockBegin* x) { /* nothing to do */ }; |
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166 void do_Goto (Goto* x) { /* nothing to do */ }; |
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167 void do_If (If* x) { /* nothing to do */ }; |
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168 void do_IfInstanceOf (IfInstanceOf* x) { /* nothing to do */ }; |
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169 void do_TableSwitch (TableSwitch* x) { /* nothing to do */ }; |
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170 void do_LookupSwitch (LookupSwitch* x) { /* nothing to do */ }; |
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171 void do_Return (Return* x) { /* nothing to do */ }; |
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172 void do_Throw (Throw* x) { /* nothing to do */ }; |
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173 void do_Base (Base* x) { /* nothing to do */ }; |
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174 void do_OsrEntry (OsrEntry* x) { /* nothing to do */ }; |
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175 void do_ExceptionObject(ExceptionObject* x) { /* nothing to do */ }; |
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176 void do_RoundFP (RoundFP* x) { /* nothing to do */ }; |
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177 void do_UnsafeGetRaw (UnsafeGetRaw* x) { /* nothing to do */ }; |
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178 void do_UnsafeGetObject(UnsafeGetObject* x) { /* nothing to do */ }; |
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179 void do_UnsafePrefetchRead (UnsafePrefetchRead* x) { /* nothing to do */ }; |
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180 void do_UnsafePrefetchWrite(UnsafePrefetchWrite* x) { /* nothing to do */ }; |
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181 void do_ProfileCall (ProfileCall* x) { /* nothing to do */ }; |
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182 void do_ProfileCounter (ProfileCounter* x) { /* nothing to do */ }; |
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183 }; |
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184 |
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185 |
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186 class GlobalValueNumbering: public ValueNumberingVisitor { |
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187 private: |
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188 ValueMap* _current_map; // value map of current block |
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189 ValueMapArray _value_maps; // list of value maps for all blocks |
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190 |
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191 public: |
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192 // accessors |
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193 ValueMap* current_map() { return _current_map; } |
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194 ValueMap* value_map_of(BlockBegin* block) { return _value_maps.at(block->linear_scan_number()); } |
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195 void set_value_map_of(BlockBegin* block, ValueMap* map) { assert(value_map_of(block) == NULL, ""); _value_maps.at_put(block->linear_scan_number(), map); } |
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196 |
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197 // implementation for abstract methods of ValueNumberingVisitor |
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198 void kill_memory() { current_map()->kill_memory(); } |
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199 void kill_field(ciField* field) { current_map()->kill_field(field); } |
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200 void kill_array(ValueType* type) { current_map()->kill_array(type); } |
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201 |
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202 // main entry point that performs global value numbering |
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203 GlobalValueNumbering(IR* ir); |
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204 }; |