src/hotspot/share/c1/c1_ValueMap.hpp - openjdk/jdk25u - Git at Google


            
            /*

            
             * Copyright (c) 1999, 2025, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

            
             * or visit www.oracle.com if you need additional information or have any

            
             * questions.

            
             *

            
             */


            #ifndef SHARE_C1_C1_VALUEMAP_HPP

            
            #define SHARE_C1_C1_VALUEMAP_HPP


            #include "c1/c1_Instruction.hpp"

            
            #include "c1/c1_ValueSet.hpp"

            
            #include "memory/allocation.hpp"


            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; }

            
            };


            typedef GrowableArray<ValueMapEntry*> ValueMapEntryArray;

            
            typedef GrowableArray<ValueMapEntry*> ValueMapEntryList;


            // 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, bool all_offsets);

            
              void kill_array(ValueType* type);

            
              void kill_map(ValueMap* map);

            
              void kill_all();


            #ifndef PRODUCT

            
              // debugging/printing

            
              void print();


              static void reset_statistics();

            
              static void print_statistics();

            
            #endif

            
            };


            typedef GrowableArray<ValueMap*> ValueMapArray;


            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, bool all_offsets) = 0;

            
              virtual void kill_array(ValueType* type) = 0;


              // visitor functions

            
              void do_StoreField     (StoreField*      x) {

            
                if (x->is_init_point() ||  // putstatic is an initialization point so treat it as a wide kill

            
                    // This is actually too strict and the JMM doesn't require

            
                    // this in all cases (e.g. load a; volatile store b; load a)

            
                    // but possible future optimizations might require this.

            
                    x->field()->is_volatile()) {

            
                  kill_memory();

            
                } else {

            
                  kill_field(x->field(), x->needs_patching());

            
                }

            
              }

            
              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_UnsafePut      (UnsafePut*       x) { kill_memory(); }

            
              void do_UnsafeGetAndSet(UnsafeGetAndSet* x) { kill_memory(); }

            
              void do_UnsafeGet      (UnsafeGet*       x) {

            
                if (x->is_volatile()) { // the JMM requires this

            
                  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) {

            
                if (x->kills_memory()) {

            
                  assert(x->can_trap(), "already linked");

            
                  kill_memory();

            
                }

            
              }

            
              void do_LoadField      (LoadField*       x) {

            
                if (x->is_init_point() ||         // getstatic is an initialization point so treat it as a wide kill

            
                    x->field()->is_volatile()) {  // the JMM requires this

            
                  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_TypeCast       (TypeCast*        x) { /* nothing to do */ }

            
              void do_NewInstance    (NewInstance*     x) {

            
                ciInstanceKlass* c = x->klass();

            
                if (c != nullptr && !c->is_initialized() &&

            
                    (!c->is_loaded() || c->has_class_initializer())) {

            
                  kill_memory();

            
                }

            
              }

            
              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_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_ProfileCall    (ProfileCall*     x) { /* nothing to do */ }

            
              void do_ProfileReturnType (ProfileReturnType*  x) { /* nothing to do */ }

            
              void do_ProfileInvoke  (ProfileInvoke*   x) { /* nothing to do */ };

            
              void do_RuntimeCall    (RuntimeCall*     x) { /* nothing to do */ };

            
              void do_MemBar         (MemBar*          x) { /* nothing to do */ };

            
              void do_RangeCheckPredicate(RangeCheckPredicate* x) { /* nothing to do */ };

            
            #ifdef ASSERT

            
              void do_Assert         (Assert*          x) { /* nothing to do */ };

            
            #endif

            
            };


            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, bool all_offsets)  { _map->kill_field(field, all_offsets); }

            
              void          kill_array(ValueType* type)                   { _map->kill_array(type); }


              ValueNumberingEffects(ValueMap* map): _map(map) {}

            
            };


            class GlobalValueNumbering: public ValueNumberingVisitor {

            
             private:

            
              Compilation*  _compilation;     // compilation data

            
              ValueMap*     _current_map;     // value map of current block

            
              ValueMapArray _value_maps;      // list of value maps for all blocks

            
              ValueSet      _processed_values;  // marker for instructions that were already processed

            
              bool          _has_substitutions; // set to true when substitutions must be resolved


             public:

            
              // accessors

            
              Compilation*  compilation() const              { return _compilation; }

            
              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) == nullptr, ""); _value_maps.at_put(block->linear_scan_number(), map); }


              bool          is_processed(Value v)            { return _processed_values.contains(v); }

            
              void          set_processed(Value v)           { _processed_values.put(v); }


              // implementation for abstract methods of ValueNumberingVisitor

            
              void          kill_memory()                                 { current_map()->kill_memory(); }

            
              void          kill_field(ciField* field, bool all_offsets)  { current_map()->kill_field(field, all_offsets); }

            
              void          kill_array(ValueType* type)                   { current_map()->kill_array(type); }


              // main entry point that performs global value numbering

            
              GlobalValueNumbering(IR* ir);

            
              void          substitute(Instruction* instr);  // substitute instruction if it is contained in current value map

            
            };


            #endif // SHARE_C1_C1_VALUEMAP_HPP
	/*
	* Copyright (c) 1999, 2025, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*
	*/

	#ifndef SHARE_C1_C1_VALUEMAP_HPP
	#define SHARE_C1_C1_VALUEMAP_HPP

	#include "c1/c1_Instruction.hpp"
	#include "c1/c1_ValueSet.hpp"
	#include "memory/allocation.hpp"

	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; }
	};

	typedef GrowableArray<ValueMapEntry*> ValueMapEntryArray;
	typedef GrowableArray<ValueMapEntry*> ValueMapEntryList;

	// 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, bool all_offsets);
	void kill_array(ValueType* type);
	void kill_map(ValueMap* map);
	void kill_all();

	#ifndef PRODUCT
	// debugging/printing
	void print();

	static void reset_statistics();
	static void print_statistics();
	#endif
	};

	typedef GrowableArray<ValueMap*> ValueMapArray;

	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, bool all_offsets) = 0;
	virtual void kill_array(ValueType* type) = 0;

	// visitor functions
	void do_StoreField (StoreField* x) {
	if (x->is_init_point() \|\| // putstatic is an initialization point so treat it as a wide kill
	// This is actually too strict and the JMM doesn't require
	// this in all cases (e.g. load a; volatile store b; load a)
	// but possible future optimizations might require this.
	x->field()->is_volatile()) {
	kill_memory();
	} else {
	kill_field(x->field(), x->needs_patching());
	}
	}
	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_UnsafePut (UnsafePut* x) { kill_memory(); }
	void do_UnsafeGetAndSet(UnsafeGetAndSet* x) { kill_memory(); }
	void do_UnsafeGet (UnsafeGet* x) {
	if (x->is_volatile()) { // the JMM requires this
	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) {
	if (x->kills_memory()) {
	assert(x->can_trap(), "already linked");
	kill_memory();
	}
	}
	void do_LoadField (LoadField* x) {
	if (x->is_init_point() \|\| // getstatic is an initialization point so treat it as a wide kill
	x->field()->is_volatile()) { // the JMM requires this
	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_TypeCast (TypeCast* x) { /* nothing to do */ }
	void do_NewInstance (NewInstance* x) {
	ciInstanceKlass* c = x->klass();
	if (c != nullptr && !c->is_initialized() &&
	(!c->is_loaded() \|\| c->has_class_initializer())) {
	kill_memory();
	}
	}
	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_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_ProfileCall (ProfileCall* x) { /* nothing to do */ }
	void do_ProfileReturnType (ProfileReturnType* x) { /* nothing to do */ }
	void do_ProfileInvoke (ProfileInvoke* x) { /* nothing to do */ };
	void do_RuntimeCall (RuntimeCall* x) { /* nothing to do */ };
	void do_MemBar (MemBar* x) { /* nothing to do */ };
	void do_RangeCheckPredicate(RangeCheckPredicate* x) { /* nothing to do */ };
	#ifdef ASSERT
	void do_Assert (Assert* x) { /* nothing to do */ };
	#endif
	};


	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, bool all_offsets) { _map->kill_field(field, all_offsets); }
	void kill_array(ValueType* type) { _map->kill_array(type); }

	ValueNumberingEffects(ValueMap* map): _map(map) {}
	};


	class GlobalValueNumbering: public ValueNumberingVisitor {
	private:
	Compilation* _compilation; // compilation data
	ValueMap* _current_map; // value map of current block
	ValueMapArray _value_maps; // list of value maps for all blocks
	ValueSet _processed_values; // marker for instructions that were already processed
	bool _has_substitutions; // set to true when substitutions must be resolved

	public:
	// accessors
	Compilation* compilation() const { return _compilation; }
	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) == nullptr, ""); _value_maps.at_put(block->linear_scan_number(), map); }

	bool is_processed(Value v) { return _processed_values.contains(v); }
	void set_processed(Value v) { _processed_values.put(v); }

	// implementation for abstract methods of ValueNumberingVisitor
	void kill_memory() { current_map()->kill_memory(); }
	void kill_field(ciField* field, bool all_offsets) { current_map()->kill_field(field, all_offsets); }
	void kill_array(ValueType* type) { current_map()->kill_array(type); }

	// main entry point that performs global value numbering
	GlobalValueNumbering(IR* ir);
	void substitute(Instruction* instr); // substitute instruction if it is contained in current value map
	};

	#endif // SHARE_C1_C1_VALUEMAP_HPP