1/* 2 * Copyright (c) 1999, 2016, 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 32class 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 56typedef GrowableArray<ValueMapEntry*> ValueMapEntryArray; 57typedef GrowableArray<ValueMapEntry*> ValueMapEntryList; 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 74class 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, bool all_offsets); 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 132typedef GrowableArray<ValueMap*> ValueMapArray; 133 134class ValueNumberingVisitor: public InstructionVisitor { 135 protected: 136 // called by visitor functions for instructions that kill values 137 virtual void kill_memory() = 0; 138 virtual void kill_field(ciField* field, bool all_offsets) = 0; 139 virtual void kill_array(ValueType* type) = 0; 140 141 // visitor functions 142 void do_StoreField (StoreField* x) { 143 if (x->is_init_point() || // putstatic is an initialization point so treat it as a wide kill 144 // This is actually too strict and the JMM doesn't require 145 // this in all cases (e.g. load a; volatile store b; load a) 146 // but possible future optimizations might require this. 147 x->field()->is_volatile()) { 148 kill_memory(); 149 } else { 150 kill_field(x->field(), x->needs_patching()); 151 } 152 } 153 void do_StoreIndexed (StoreIndexed* x) { kill_array(x->type()); } 154 void do_MonitorEnter (MonitorEnter* x) { kill_memory(); } 155 void do_MonitorExit (MonitorExit* x) { kill_memory(); } 156 void do_Invoke (Invoke* x) { kill_memory(); } 157 void do_UnsafePutRaw (UnsafePutRaw* x) { kill_memory(); } 158 void do_UnsafePutObject(UnsafePutObject* x) { kill_memory(); } 159 void do_UnsafeGetAndSetObject(UnsafeGetAndSetObject* x) { kill_memory(); } 160 void do_UnsafeGetRaw (UnsafeGetRaw* x) { /* nothing to do */ } 161 void do_UnsafeGetObject(UnsafeGetObject* x) { 162 if (x->is_volatile()) { // the JMM requires this 163 kill_memory(); 164 } 165 } 166 void do_Intrinsic (Intrinsic* x) { if (!x->preserves_state()) kill_memory(); } 167 168 void do_Phi (Phi* x) { /* nothing to do */ } 169 void do_Local (Local* x) { /* nothing to do */ } 170 void do_Constant (Constant* x) { /* nothing to do */ } 171 void do_LoadField (LoadField* x) { 172 if (x->is_init_point() || // getstatic is an initialization point so treat it as a wide kill 173 x->field()->is_volatile()) { // the JMM requires this 174 kill_memory(); 175 } 176 } 177 void do_ArrayLength (ArrayLength* x) { /* nothing to do */ } 178 void do_LoadIndexed (LoadIndexed* x) { /* nothing to do */ } 179 void do_NegateOp (NegateOp* x) { /* nothing to do */ } 180 void do_ArithmeticOp (ArithmeticOp* x) { /* nothing to do */ } 181 void do_ShiftOp (ShiftOp* x) { /* nothing to do */ } 182 void do_LogicOp (LogicOp* x) { /* nothing to do */ } 183 void do_CompareOp (CompareOp* x) { /* nothing to do */ } 184 void do_IfOp (IfOp* x) { /* nothing to do */ } 185 void do_Convert (Convert* x) { /* nothing to do */ } 186 void do_NullCheck (NullCheck* x) { /* nothing to do */ } 187 void do_TypeCast (TypeCast* x) { /* nothing to do */ } 188 void do_NewInstance (NewInstance* x) { /* nothing to do */ } 189 void do_NewTypeArray (NewTypeArray* x) { /* nothing to do */ } 190 void do_NewObjectArray (NewObjectArray* x) { /* nothing to do */ } 191 void do_NewMultiArray (NewMultiArray* x) { /* nothing to do */ } 192 void do_CheckCast (CheckCast* x) { /* nothing to do */ } 193 void do_InstanceOf (InstanceOf* x) { /* nothing to do */ } 194 void do_BlockBegin (BlockBegin* x) { /* nothing to do */ } 195 void do_Goto (Goto* x) { /* nothing to do */ } 196 void do_If (If* x) { /* nothing to do */ } 197 void do_IfInstanceOf (IfInstanceOf* x) { /* nothing to do */ } 198 void do_TableSwitch (TableSwitch* x) { /* nothing to do */ } 199 void do_LookupSwitch (LookupSwitch* x) { /* nothing to do */ } 200 void do_Return (Return* x) { /* nothing to do */ } 201 void do_Throw (Throw* x) { /* nothing to do */ } 202 void do_Base (Base* x) { /* nothing to do */ } 203 void do_OsrEntry (OsrEntry* x) { /* nothing to do */ } 204 void do_ExceptionObject(ExceptionObject* x) { /* nothing to do */ } 205 void do_RoundFP (RoundFP* x) { /* nothing to do */ } 206 void do_ProfileCall (ProfileCall* x) { /* nothing to do */ } 207 void do_ProfileReturnType (ProfileReturnType* x) { /* nothing to do */ } 208 void do_ProfileInvoke (ProfileInvoke* x) { /* nothing to do */ }; 209 void do_RuntimeCall (RuntimeCall* x) { /* nothing to do */ }; 210 void do_MemBar (MemBar* x) { /* nothing to do */ }; 211 void do_RangeCheckPredicate(RangeCheckPredicate* x) { /* nothing to do */ }; 212#ifdef ASSERT 213 void do_Assert (Assert* x) { /* nothing to do */ }; 214#endif 215}; 216 217 218class ValueNumberingEffects: public ValueNumberingVisitor { 219 private: 220 ValueMap* _map; 221 222 public: 223 // implementation for abstract methods of ValueNumberingVisitor 224 void kill_memory() { _map->kill_memory(); } 225 void kill_field(ciField* field, bool all_offsets) { _map->kill_field(field, all_offsets); } 226 void kill_array(ValueType* type) { _map->kill_array(type); } 227 228 ValueNumberingEffects(ValueMap* map): _map(map) {} 229}; 230 231 232class GlobalValueNumbering: public ValueNumberingVisitor { 233 private: 234 Compilation* _compilation; // compilation data 235 ValueMap* _current_map; // value map of current block 236 ValueMapArray _value_maps; // list of value maps for all blocks 237 ValueSet _processed_values; // marker for instructions that were already processed 238 bool _has_substitutions; // set to true when substitutions must be resolved 239 240 public: 241 // accessors 242 Compilation* compilation() const { return _compilation; } 243 ValueMap* current_map() { return _current_map; } 244 ValueMap* value_map_of(BlockBegin* block) { return _value_maps.at(block->linear_scan_number()); } 245 void set_value_map_of(BlockBegin* block, ValueMap* map) { assert(value_map_of(block) == NULL, ""); _value_maps.at_put(block->linear_scan_number(), map); } 246 247 bool is_processed(Value v) { return _processed_values.contains(v); } 248 void set_processed(Value v) { _processed_values.put(v); } 249 250 // implementation for abstract methods of ValueNumberingVisitor 251 void kill_memory() { current_map()->kill_memory(); } 252 void kill_field(ciField* field, bool all_offsets) { current_map()->kill_field(field, all_offsets); } 253 void kill_array(ValueType* type) { current_map()->kill_array(type); } 254 255 // main entry point that performs global value numbering 256 GlobalValueNumbering(IR* ir); 257 void substitute(Instruction* instr); // substitute instruction if it is contained in current value map 258}; 259 260#endif // SHARE_VM_C1_C1_VALUEMAP_HPP 261