/* * Copyright 1999-2006 Sun Microsystems, Inc. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * */ class ValueMapEntry: public CompilationResourceObj { private: intx _hash; Value _value; int _nesting; ValueMapEntry* _next; public: ValueMapEntry(intx hash, Value value, int nesting, ValueMapEntry* next) : _hash(hash) , _value(value) , _nesting(nesting) , _next(next) { } intx hash() { return _hash; } Value value() { return _value; } int nesting() { return _nesting; } ValueMapEntry* next() { return _next; } void set_next(ValueMapEntry* next) { _next = next; } }; define_array(ValueMapEntryArray, ValueMapEntry*) define_stack(ValueMapEntryList, ValueMapEntryArray) // ValueMap implements nested hash tables for value numbering. It // maintains a set _killed_values which represents the instructions // which have been killed so far and an array of linked lists of // ValueMapEntries names _entries. Each ValueMapEntry has a nesting // which indicates what ValueMap nesting it belongs to. Higher // nesting values are always before lower values in the linked list. // This allows cloning of parent ValueMaps by simply copying the heads // of the list. _entry_count represents the number of reachable // entries in the ValueMap. A ValueMap is only allowed to mutate // ValueMapEntries with the same nesting level. Adding or removing // entries at the current nesting level requires updating // _entry_count. Elements in the parent's list that get killed can be // skipped if they are at the head of the list by simply moving to the // next element in the list and decrementing _entry_count. class ValueMap: public CompilationResourceObj { private: int _nesting; ValueMapEntryArray _entries; ValueSet _killed_values; int _entry_count; int nesting() { return _nesting; } bool is_local_value_numbering() { return _nesting == 0; } bool is_global_value_numbering() { return _nesting > 0; } int entry_count() { return _entry_count; } int size() { return _entries.length(); } ValueMapEntry* entry_at(int i) { return _entries.at(i); } // calculates the index of a hash value in a hash table of size n int entry_index(intx hash, int n) { return (unsigned int)hash % n; } // if entry_count > size_threshold, the size of the hash table is increased int size_threshold() { return size(); } // management of the killed-bitset for global value numbering void kill_value(Value v) { if (is_global_value_numbering()) _killed_values.put(v); } bool is_killed(Value v) { if (is_global_value_numbering()) return _killed_values.contains(v); else return false; } // helper functions void increase_table_size(); #ifndef PRODUCT static int _number_of_finds; static int _number_of_hits; static int _number_of_kills; #endif // PRODUCT public: // creation ValueMap(); // empty value map ValueMap(ValueMap* old); // value map with increased nesting // manipulation Value find_insert(Value x); void kill_memory(); void kill_field(ciField* field); void kill_array(ValueType* type); void kill_exception(); void kill_map(ValueMap* map); void kill_all(); #ifndef PRODUCT // debugging/printing void print(); static void reset_statistics(); static void print_statistics(); #endif }; define_array(ValueMapArray, ValueMap*) class ValueNumberingVisitor: public InstructionVisitor { protected: // called by visitor functions for instructions that kill values virtual void kill_memory() = 0; virtual void kill_field(ciField* field) = 0; virtual void kill_array(ValueType* type) = 0; // visitor functions void do_StoreField (StoreField* x) { if (!x->is_initialized()) { kill_memory(); } else { kill_field(x->field()); } } void do_StoreIndexed (StoreIndexed* x) { kill_array(x->type()); } void do_MonitorEnter (MonitorEnter* x) { kill_memory(); } void do_MonitorExit (MonitorExit* x) { kill_memory(); } void do_Invoke (Invoke* x) { kill_memory(); } void do_UnsafePutRaw (UnsafePutRaw* x) { kill_memory(); } void do_UnsafePutObject(UnsafePutObject* x) { kill_memory(); } void do_Intrinsic (Intrinsic* x) { if (!x->preserves_state()) kill_memory(); } void do_Phi (Phi* x) { /* nothing to do */ } void do_Local (Local* x) { /* nothing to do */ } void do_Constant (Constant* x) { /* nothing to do */ } void do_LoadField (LoadField* x) { if (!x->is_initialized()) { kill_memory(); } } void do_ArrayLength (ArrayLength* x) { /* nothing to do */ } void do_LoadIndexed (LoadIndexed* x) { /* nothing to do */ } void do_NegateOp (NegateOp* x) { /* nothing to do */ } void do_ArithmeticOp (ArithmeticOp* x) { /* nothing to do */ } void do_ShiftOp (ShiftOp* x) { /* nothing to do */ } void do_LogicOp (LogicOp* x) { /* nothing to do */ } void do_CompareOp (CompareOp* x) { /* nothing to do */ } void do_IfOp (IfOp* x) { /* nothing to do */ } void do_Convert (Convert* x) { /* nothing to do */ } void do_NullCheck (NullCheck* x) { /* nothing to do */ } void do_NewInstance (NewInstance* x) { /* nothing to do */ } void do_NewTypeArray (NewTypeArray* x) { /* nothing to do */ } void do_NewObjectArray (NewObjectArray* x) { /* nothing to do */ } void do_NewMultiArray (NewMultiArray* x) { /* nothing to do */ } void do_CheckCast (CheckCast* x) { /* nothing to do */ } void do_InstanceOf (InstanceOf* x) { /* nothing to do */ } void do_BlockBegin (BlockBegin* x) { /* nothing to do */ } void do_Goto (Goto* x) { /* nothing to do */ } void do_If (If* x) { /* nothing to do */ } void do_IfInstanceOf (IfInstanceOf* x) { /* nothing to do */ } void do_TableSwitch (TableSwitch* x) { /* nothing to do */ } void do_LookupSwitch (LookupSwitch* x) { /* nothing to do */ } void do_Return (Return* x) { /* nothing to do */ } void do_Throw (Throw* x) { /* nothing to do */ } void do_Base (Base* x) { /* nothing to do */ } void do_OsrEntry (OsrEntry* x) { /* nothing to do */ } void do_ExceptionObject(ExceptionObject* x) { /* nothing to do */ } void do_RoundFP (RoundFP* x) { /* nothing to do */ } void do_UnsafeGetRaw (UnsafeGetRaw* x) { /* nothing to do */ } void do_UnsafeGetObject(UnsafeGetObject* x) { /* nothing to do */ } void do_UnsafePrefetchRead (UnsafePrefetchRead* x) { /* nothing to do */ } void do_UnsafePrefetchWrite(UnsafePrefetchWrite* x) { /* nothing to do */ } void do_ProfileCall (ProfileCall* x) { /* nothing to do */ } void do_ProfileCounter (ProfileCounter* x) { /* nothing to do */ } }; class ValueNumberingEffects: public ValueNumberingVisitor { private: ValueMap* _map; public: // implementation for abstract methods of ValueNumberingVisitor void kill_memory() { _map->kill_memory(); } void kill_field(ciField* field) { _map->kill_field(field); } void kill_array(ValueType* type) { _map->kill_array(type); } ValueNumberingEffects(ValueMap* map): _map(map) {} }; class GlobalValueNumbering: public ValueNumberingVisitor { private: ValueMap* _current_map; // value map of current block ValueMapArray _value_maps; // list of value maps for all blocks public: // accessors ValueMap* current_map() { return _current_map; } ValueMap* value_map_of(BlockBegin* block) { return _value_maps.at(block->linear_scan_number()); } void set_value_map_of(BlockBegin* block, ValueMap* map) { assert(value_map_of(block) == NULL, ""); _value_maps.at_put(block->linear_scan_number(), map); } // implementation for abstract methods of ValueNumberingVisitor void kill_memory() { current_map()->kill_memory(); } void kill_field(ciField* field) { current_map()->kill_field(field); } void kill_array(ValueType* type) { current_map()->kill_array(type); } // main entry point that performs global value numbering GlobalValueNumbering(IR* ir); };