1 /* 2 * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_C1_C1_VALUEMAP_HPP 26 #define SHARE_VM_C1_C1_VALUEMAP_HPP 27 28 #include "c1/c1_Instruction.hpp" 29 #include "c1/c1_ValueSet.hpp" 30 #include "memory/allocation.hpp" 31 32 class ValueMapEntry: public CompilationResourceObj { 33 private: 34 intx _hash; 35 Value _value; 36 int _nesting; 37 ValueMapEntry* _next; 38 39 public: 40 ValueMapEntry(intx hash, Value value, int nesting, ValueMapEntry* next) 41 : _hash(hash) 42 , _value(value) 43 , _nesting(nesting) 44 , _next(next) 45 { 46 } 47 48 intx hash() { return _hash; } 49 Value value() { return _value; } 50 int nesting() { return _nesting; } 51 ValueMapEntry* next() { return _next; } 52 53 void set_next(ValueMapEntry* next) { _next = next; } 54 }; 55 56 define_array(ValueMapEntryArray, ValueMapEntry*) 57 define_stack(ValueMapEntryList, ValueMapEntryArray) 58 59 // ValueMap implements nested hash tables for value numbering. It 60 // maintains a set _killed_values which represents the instructions 61 // which have been killed so far and an array of linked lists of 62 // ValueMapEntries names _entries. Each ValueMapEntry has a nesting 63 // which indicates what ValueMap nesting it belongs to. Higher 64 // nesting values are always before lower values in the linked list. 65 // This allows cloning of parent ValueMaps by simply copying the heads 66 // of the list. _entry_count represents the number of reachable 67 // entries in the ValueMap. A ValueMap is only allowed to mutate 68 // ValueMapEntries with the same nesting level. Adding or removing 69 // entries at the current nesting level requires updating 70 // _entry_count. Elements in the parent's list that get killed can be 71 // skipped if they are at the head of the list by simply moving to the 72 // next element in the list and decrementing _entry_count. 73 74 class ValueMap: public CompilationResourceObj { 75 private: 76 int _nesting; 77 ValueMapEntryArray _entries; 78 ValueSet _killed_values; 79 int _entry_count; 80 81 int nesting() { return _nesting; } 82 bool is_local_value_numbering() { return _nesting == 0; } 83 bool is_global_value_numbering() { return _nesting > 0; } 84 85 int entry_count() { return _entry_count; } 86 int size() { return _entries.length(); } 87 ValueMapEntry* entry_at(int i) { return _entries.at(i); } 88 89 // calculates the index of a hash value in a hash table of size n 90 int entry_index(intx hash, int n) { return (unsigned int)hash % n; } 91 92 // if entry_count > size_threshold, the size of the hash table is increased 93 int size_threshold() { return size(); } 94 95 // management of the killed-bitset for global value numbering 96 void kill_value(Value v) { if (is_global_value_numbering()) _killed_values.put(v); } 97 bool is_killed(Value v) { if (is_global_value_numbering()) return _killed_values.contains(v); else return false; } 98 99 // helper functions 100 void increase_table_size(); 101 102 #ifndef PRODUCT 103 static int _number_of_finds; 104 static int _number_of_hits; 105 static int _number_of_kills; 106 #endif // PRODUCT 107 108 public: 109 // creation 110 ValueMap(); // empty value map 111 ValueMap(ValueMap* old); // value map with increased nesting 112 113 // manipulation 114 Value find_insert(Value x); 115 116 void kill_memory(); 117 void kill_field(ciField* field); 118 void kill_array(ValueType* type); 119 void kill_exception(); 120 void kill_map(ValueMap* map); 121 void kill_all(); 122 123 #ifndef PRODUCT 124 // debugging/printing 125 void print(); 126 127 static void reset_statistics(); 128 static void print_statistics(); 129 #endif 130 }; 131 132 define_array(ValueMapArray, ValueMap*) 133 134 135 class ValueNumberingVisitor: public InstructionVisitor { 136 protected: 137 // called by visitor functions for instructions that kill values 138 virtual void kill_memory() = 0; 139 virtual void kill_field(ciField* field) = 0; 140 virtual void kill_array(ValueType* type) = 0; 141 142 // visitor functions 143 void do_StoreField (StoreField* x) { 144 if (x->is_init_point()) { 145 // putstatic is an initialization point so treat it as a wide kill 146 kill_memory(); 147 } else { 148 kill_field(x->field()); 149 } 150 } 151 void do_StoreIndexed (StoreIndexed* x) { kill_array(x->type()); } 152 void do_MonitorEnter (MonitorEnter* x) { kill_memory(); } 153 void do_MonitorExit (MonitorExit* x) { kill_memory(); } 154 void do_Invoke (Invoke* x) { kill_memory(); } 155 void do_UnsafePutRaw (UnsafePutRaw* x) { kill_memory(); } 156 void do_UnsafePutObject(UnsafePutObject* x) { kill_memory(); } 157 void do_Intrinsic (Intrinsic* x) { if (!x->preserves_state()) kill_memory(); } 158 159 void do_Phi (Phi* x) { /* nothing to do */ } 160 void do_Local (Local* x) { /* nothing to do */ } 161 void do_Constant (Constant* x) { /* nothing to do */ } 162 void do_LoadField (LoadField* x) { 163 if (x->is_init_point()) { 164 // getstatic is an initialization point so treat it as a wide kill 165 kill_memory(); 166 } 167 } 168 void do_ArrayLength (ArrayLength* x) { /* nothing to do */ } 169 void do_LoadIndexed (LoadIndexed* x) { /* nothing to do */ } 170 void do_NegateOp (NegateOp* x) { /* nothing to do */ } 171 void do_ArithmeticOp (ArithmeticOp* x) { /* nothing to do */ } 172 void do_ShiftOp (ShiftOp* x) { /* nothing to do */ } 173 void do_LogicOp (LogicOp* x) { /* nothing to do */ } 174 void do_CompareOp (CompareOp* x) { /* nothing to do */ } 175 void do_IfOp (IfOp* x) { /* nothing to do */ } 176 void do_Convert (Convert* x) { /* nothing to do */ } 177 void do_NullCheck (NullCheck* x) { /* nothing to do */ } 178 void do_NewInstance (NewInstance* x) { /* nothing to do */ } 179 void do_NewTypeArray (NewTypeArray* x) { /* nothing to do */ } 180 void do_NewObjectArray (NewObjectArray* x) { /* nothing to do */ } 181 void do_NewMultiArray (NewMultiArray* x) { /* nothing to do */ } 182 void do_CheckCast (CheckCast* x) { /* nothing to do */ } 183 void do_InstanceOf (InstanceOf* x) { /* nothing to do */ } 184 void do_BlockBegin (BlockBegin* x) { /* nothing to do */ } 185 void do_Goto (Goto* x) { /* nothing to do */ } 186 void do_If (If* x) { /* nothing to do */ } 187 void do_IfInstanceOf (IfInstanceOf* x) { /* nothing to do */ } 188 void do_TableSwitch (TableSwitch* x) { /* nothing to do */ } 189 void do_LookupSwitch (LookupSwitch* x) { /* nothing to do */ } 190 void do_Return (Return* x) { /* nothing to do */ } 191 void do_Throw (Throw* x) { /* nothing to do */ } 192 void do_Base (Base* x) { /* nothing to do */ } 193 void do_OsrEntry (OsrEntry* x) { /* nothing to do */ } 194 void do_ExceptionObject(ExceptionObject* x) { /* nothing to do */ } 195 void do_RoundFP (RoundFP* x) { /* nothing to do */ } 196 void do_UnsafeGetRaw (UnsafeGetRaw* x) { /* nothing to do */ } 197 void do_UnsafeGetObject(UnsafeGetObject* x) { /* nothing to do */ } 198 void do_UnsafePrefetchRead (UnsafePrefetchRead* x) { /* nothing to do */ } 199 void do_UnsafePrefetchWrite(UnsafePrefetchWrite* x) { /* nothing to do */ } 200 void do_ProfileCall (ProfileCall* x) { /* nothing to do */ } 201 void do_ProfileInvoke (ProfileInvoke* x) { /* nothing to do */ }; 202 void do_RuntimeCall (RuntimeCall* x) { /* nothing to do */ }; 203 }; 204 205 206 class ValueNumberingEffects: public ValueNumberingVisitor { 207 private: 208 ValueMap* _map; 209 210 public: 211 // implementation for abstract methods of ValueNumberingVisitor 212 void kill_memory() { _map->kill_memory(); } 213 void kill_field(ciField* field) { _map->kill_field(field); } 214 void kill_array(ValueType* type) { _map->kill_array(type); } 215 216 ValueNumberingEffects(ValueMap* map): _map(map) {} 217 }; 218 219 220 class GlobalValueNumbering: public ValueNumberingVisitor { 221 private: 222 ValueMap* _current_map; // value map of current block 223 ValueMapArray _value_maps; // list of value maps for all blocks 224 225 public: 226 // accessors 227 ValueMap* current_map() { return _current_map; } 228 ValueMap* value_map_of(BlockBegin* block) { return _value_maps.at(block->linear_scan_number()); } 229 void set_value_map_of(BlockBegin* block, ValueMap* map) { assert(value_map_of(block) == NULL, ""); _value_maps.at_put(block->linear_scan_number(), map); } 230 231 // implementation for abstract methods of ValueNumberingVisitor 232 void kill_memory() { current_map()->kill_memory(); } 233 void kill_field(ciField* field) { current_map()->kill_field(field); } 234 void kill_array(ValueType* type) { current_map()->kill_array(type); } 235 236 // main entry point that performs global value numbering 237 GlobalValueNumbering(IR* ir); 238 }; 239 240 #endif // SHARE_VM_C1_C1_VALUEMAP_HPP