/*

 * Copyright (c) 2005, 2006, 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.

 *

 */

// The classes responsible for code emission and register allocation

class LIRGenerator;

class LIREmitter;

class Invoke;

class SwitchRange;

class LIRItem;

define_array(LIRItemArray, LIRItem*)

define_stack(LIRItemList, LIRItemArray)

class SwitchRange: public CompilationResourceObj {

 private:

  int _low_key;

  int _high_key;

  BlockBegin* _sux;

 public:

  SwitchRange(int start_key, BlockBegin* sux): _low_key(start_key), _high_key(start_key), _sux(sux) {}

  void set_high_key(int key) { _high_key = key; }

  int high_key() const { return _high_key; }

  int low_key() const { return _low_key; }

  BlockBegin* sux() const { return _sux; }

};

define_array(SwitchRangeArray, SwitchRange*)

define_stack(SwitchRangeList, SwitchRangeArray)

class ResolveNode;

define_array(NodeArray, ResolveNode*);

define_stack(NodeList, NodeArray);

// Node objects form a directed graph of LIR_Opr

// Edges between Nodes represent moves from one Node to its destinations

class ResolveNode: public CompilationResourceObj {

 private:

  LIR_Opr    _operand;       // the source or destinaton

  NodeList   _destinations;  // for the operand

  bool       _assigned;      // Value assigned to this Node?

  bool       _visited;       // Node already visited?

  bool       _start_node;    // Start node already visited?

 public:

  ResolveNode(LIR_Opr operand)

    : _operand(operand)

    , _assigned(false)

    , _visited(false)

    , _start_node(false) {};

  // accessors

  LIR_Opr operand() const           { return _operand; }

  int no_of_destinations() const    { return _destinations.length(); }

  ResolveNode* destination_at(int i)     { return _destinations[i]; }

  bool assigned() const             { return _assigned; }

  bool visited() const              { return _visited; }

  bool start_node() const           { return _start_node; }

  // modifiers

  void append(ResolveNode* dest)         { _destinations.append(dest); }

  void set_assigned()               { _assigned = true; }

  void set_visited()                { _visited = true; }

  void set_start_node()             { _start_node = true; }

};

// This is shared state to be used by the PhiResolver so the operand

// arrays don't have to be reallocated for reach resolution.

class PhiResolverState: public CompilationResourceObj {

  friend class PhiResolver;

 private:

  NodeList _virtual_operands; // Nodes where the operand is a virtual register

  NodeList _other_operands;   // Nodes where the operand is not a virtual register

  NodeList _vreg_table;       // Mapping from virtual register to Node

 public:

  PhiResolverState() {}

  void reset(int max_vregs);

};

// class used to move value of phi operand to phi function

class PhiResolver: public CompilationResourceObj {

 private:

  LIRGenerator*     _gen;

  PhiResolverState& _state; // temporary state cached by LIRGenerator

  ResolveNode*   _loop;

  LIR_Opr _temp;

  // access to shared state arrays

  NodeList& virtual_operands() { return _state._virtual_operands; }

  NodeList& other_operands()   { return _state._other_operands;   }

  NodeList& vreg_table()       { return _state._vreg_table;       }

  ResolveNode* create_node(LIR_Opr opr, bool source);

  ResolveNode* source_node(LIR_Opr opr)      { return create_node(opr, true); }

  ResolveNode* destination_node(LIR_Opr opr) { return create_node(opr, false); }

  void emit_move(LIR_Opr src, LIR_Opr dest);

  void move_to_temp(LIR_Opr src);

  void move_temp_to(LIR_Opr dest);

  void move(ResolveNode* src, ResolveNode* dest);

  LIRGenerator* gen() {

    return _gen;

  }

 public:

  PhiResolver(LIRGenerator* _lir_gen, int max_vregs);

  ~PhiResolver();

  void move(LIR_Opr src, LIR_Opr dest);

};

// only the classes below belong in the same file

class LIRGenerator: public InstructionVisitor, public BlockClosure {

 private:

  Compilation*  _compilation;

  ciMethod*     _method;    // method that we are compiling

  PhiResolverState  _resolver_state;

  BlockBegin*   _block;

  int           _virtual_register_number;

  Values        _instruction_for_operand;

  BitMap2D      _vreg_flags; // flags which can be set on a per-vreg basis

  LIR_List*     _lir;

  BarrierSet*   _bs;

  LIRGenerator* gen() {

    return this;

  }

#ifdef ASSERT

  LIR_List* lir(const char * file, int line) const {

    _lir->set_file_and_line(file, line);

    return _lir;

  }

#endif

  LIR_List* lir() const {

    return _lir;

  }

  // a simple cache of constants used within a block

  GrowableArray<LIR_Const*>       _constants;

  LIR_OprList                     _reg_for_constants;

  Values                          _unpinned_constants;

  friend class PhiResolver;

  // unified bailout support

  void bailout(const char* msg) const            { compilation()->bailout(msg); }

  bool bailed_out() const                        { return compilation()->bailed_out(); }

  void block_do_prolog(BlockBegin* block);

  void block_do_epilog(BlockBegin* block);

  // register allocation

  LIR_Opr rlock(Value instr);                      // lock a free register

  LIR_Opr rlock_result(Value instr);

  LIR_Opr rlock_result(Value instr, BasicType type);

  LIR_Opr rlock_byte(BasicType type);

  LIR_Opr rlock_callee_saved(BasicType type);

  // get a constant into a register and get track of what register was used

  LIR_Opr load_constant(Constant* x);

  LIR_Opr load_constant(LIR_Const* constant);

  void  set_result(Value x, LIR_Opr opr)           {

    assert(opr->is_valid(), "must set to valid value");

    assert(x->operand()->is_illegal(), "operand should never change");

    assert(!opr->is_register() || opr->is_virtual(), "should never set result to a physical register");

    x->set_operand(opr);

    assert(opr == x->operand(), "must be");

    if (opr->is_virtual()) {

      _instruction_for_operand.at_put_grow(opr->vreg_number(), x, NULL);

    }

  }

  void  set_no_result(Value x)                     { assert(!x->has_uses(), "can't have use"); x->clear_operand(); }

  friend class LIRItem;

  LIR_Opr round_item(LIR_Opr opr);

  LIR_Opr force_to_spill(LIR_Opr value, BasicType t);

  void  profile_branch(If* if_instr, If::Condition cond);

  PhiResolverState& resolver_state() { return _resolver_state; }

  void  move_to_phi(PhiResolver* resolver, Value cur_val, Value sux_val);

  void  move_to_phi(ValueStack* cur_state);

  // code emission

  void do_ArithmeticOp_Long   (ArithmeticOp*    x);

  void do_ArithmeticOp_Int    (ArithmeticOp*    x);

  void do_ArithmeticOp_FPU    (ArithmeticOp*    x);

  // platform dependent

  LIR_Opr getThreadPointer();

  void do_RegisterFinalizer(Intrinsic* x);

  void do_getClass(Intrinsic* x);

  void do_currentThread(Intrinsic* x);

  void do_MathIntrinsic(Intrinsic* x);

  void do_ArrayCopy(Intrinsic* x);

  void do_CompareAndSwap(Intrinsic* x, ValueType* type);

  void do_AttemptUpdate(Intrinsic* x);

  void do_NIOCheckIndex(Intrinsic* x);

  void do_FPIntrinsics(Intrinsic* x);

  void do_UnsafePrefetch(UnsafePrefetch* x, bool is_store);

  LIR_Opr call_runtime(BasicTypeArray* signature, LIRItemList* args, address entry, ValueType* result_type, CodeEmitInfo* info);

  LIR_Opr call_runtime(BasicTypeArray* signature, LIR_OprList* args, address entry, ValueType* result_type, CodeEmitInfo* info);

  // convenience functions

  LIR_Opr call_runtime(Value arg1, address entry, ValueType* result_type, CodeEmitInfo* info);

  LIR_Opr call_runtime(Value arg1, Value arg2, address entry, ValueType* result_type, CodeEmitInfo* info);

  // GC Barriers

  // generic interface

  void pre_barrier(LIR_Opr addr_opr, bool patch,  CodeEmitInfo* info);

  void post_barrier(LIR_OprDesc* addr, LIR_OprDesc* new_val);

  // specific implementations

  // pre barriers

  void G1SATBCardTableModRef_pre_barrier(LIR_Opr addr_opr, bool patch,  CodeEmitInfo* info);

  // post barriers

  void G1SATBCardTableModRef_post_barrier(LIR_OprDesc* addr, LIR_OprDesc* new_val);

  void CardTableModRef_post_barrier(LIR_OprDesc* addr, LIR_OprDesc* new_val);

  static LIR_Opr result_register_for(ValueType* type, bool callee = false);

  ciObject* get_jobject_constant(Value value);

  LIRItemList* invoke_visit_arguments(Invoke* x);

  void invoke_load_arguments(Invoke* x, LIRItemList* args, const LIR_OprList* arg_list);

  void trace_block_entry(BlockBegin* block);

  // volatile field operations are never patchable because a klass

  // must be loaded to know it's volatile which means that the offset

  // it always known as well.

  void volatile_field_store(LIR_Opr value, LIR_Address* address, CodeEmitInfo* info);

  void volatile_field_load(LIR_Address* address, LIR_Opr result, CodeEmitInfo* info);

  void put_Object_unsafe(LIR_Opr src, LIR_Opr offset, LIR_Opr data, BasicType type, bool is_volatile);

  void get_Object_unsafe(LIR_Opr dest, LIR_Opr src, LIR_Opr offset, BasicType type, bool is_volatile);

  void arithmetic_call_op (Bytecodes::Code code, LIR_Opr result, LIR_OprList* args);

  void increment_counter(address counter, int step = 1);

  void increment_counter(LIR_Address* addr, int step = 1);

  // increment a counter returning the incremented value

  LIR_Opr increment_and_return_counter(LIR_Opr base, int offset, int increment);

  // is_strictfp is only needed for mul and div (and only generates different code on i486)

  void arithmetic_op(Bytecodes::Code code, LIR_Opr result, LIR_Opr left, LIR_Opr right, bool is_strictfp, LIR_Opr tmp, CodeEmitInfo* info = NULL);

  // machine dependent.  returns true if it emitted code for the multiply

  bool strength_reduce_multiply(LIR_Opr left, int constant, LIR_Opr result, LIR_Opr tmp);

  void store_stack_parameter (LIR_Opr opr, ByteSize offset_from_sp_in_bytes);

  void jobject2reg_with_patching(LIR_Opr r, ciObject* obj, CodeEmitInfo* info);

  // this loads the length and compares against the index

  void array_range_check          (LIR_Opr array, LIR_Opr index, CodeEmitInfo* null_check_info, CodeEmitInfo* range_check_info);

  // For java.nio.Buffer.checkIndex

  void nio_range_check            (LIR_Opr buffer, LIR_Opr index, LIR_Opr result, CodeEmitInfo* info);

  void arithmetic_op_int  (Bytecodes::Code code, LIR_Opr result, LIR_Opr left, LIR_Opr right, LIR_Opr tmp);

  void arithmetic_op_long (Bytecodes::Code code, LIR_Opr result, LIR_Opr left, LIR_Opr right, CodeEmitInfo* info = NULL);

  void arithmetic_op_fpu  (Bytecodes::Code code, LIR_Opr result, LIR_Opr left, LIR_Opr right, bool is_strictfp, LIR_Opr tmp = LIR_OprFact::illegalOpr);

  void shift_op   (Bytecodes::Code code, LIR_Opr dst_reg, LIR_Opr value, LIR_Opr count, LIR_Opr tmp);

  void logic_op   (Bytecodes::Code code, LIR_Opr dst_reg, LIR_Opr left, LIR_Opr right);

  void monitor_enter (LIR_Opr object, LIR_Opr lock, LIR_Opr hdr, LIR_Opr scratch, int monitor_no, CodeEmitInfo* info_for_exception, CodeEmitInfo* info);

  void monitor_exit  (LIR_Opr object, LIR_Opr lock, LIR_Opr hdr, int monitor_no);

  void new_instance    (LIR_Opr  dst, ciInstanceKlass* klass, LIR_Opr  scratch1, LIR_Opr  scratch2, LIR_Opr  scratch3,  LIR_Opr scratch4, LIR_Opr  klass_reg, CodeEmitInfo* info);

  // machine dependent

  void cmp_mem_int(LIR_Condition condition, LIR_Opr base, int disp, int c, CodeEmitInfo* info);

  void cmp_reg_mem(LIR_Condition condition, LIR_Opr reg, LIR_Opr base, int disp, BasicType type, CodeEmitInfo* info);

  void cmp_reg_mem(LIR_Condition condition, LIR_Opr reg, LIR_Opr base, LIR_Opr disp, BasicType type, CodeEmitInfo* info);

  void arraycopy_helper(Intrinsic* x, int* flags, ciArrayKlass** expected_type);

  // returns a LIR_Address to address an array location.  May also

  // emit some code as part of address calculation.  If

  // needs_card_mark is true then compute the full address for use by

  // both the store and the card mark.

  LIR_Address* generate_address(LIR_Opr base,

                                LIR_Opr index, int shift,

                                int disp,

                                BasicType type);

  LIR_Address* generate_address(LIR_Opr base, int disp, BasicType type) {

    return generate_address(base, LIR_OprFact::illegalOpr, 0, disp, type);

  }

  LIR_Address* emit_array_address(LIR_Opr array_opr, LIR_Opr index_opr, BasicType type, bool needs_card_mark);

  // machine preferences and characteristics

  bool can_inline_as_constant(Value i) const;

  bool can_inline_as_constant(LIR_Const* c) const;

  bool can_store_as_constant(Value i, BasicType type) const;

  LIR_Opr safepoint_poll_register();

  void increment_invocation_counter(CodeEmitInfo* info, bool backedge = false);

  void increment_backedge_counter(CodeEmitInfo* info) {

    increment_invocation_counter(info, true);

  }

  CodeEmitInfo* state_for(Instruction* x, ValueStack* state, bool ignore_xhandler = false);

  CodeEmitInfo* state_for(Instruction* x);

  // allocates a virtual register for this instruction if

  // one isn't already allocated.  Only for Phi and Local.

  LIR_Opr operand_for_instruction(Instruction *x);

  void set_block(BlockBegin* block)              { _block = block; }

  void block_prolog(BlockBegin* block);

  void block_epilog(BlockBegin* block);

  void do_root (Instruction* instr);

  void walk    (Instruction* instr);

  void bind_block_entry(BlockBegin* block);

  void start_block(BlockBegin* block);

  LIR_Opr new_register(BasicType type);

  LIR_Opr new_register(Value value)              { return new_register(as_BasicType(value->type())); }

  LIR_Opr new_register(ValueType* type)          { return new_register(as_BasicType(type)); }

  // returns a register suitable for doing pointer math

  LIR_Opr new_pointer_register() {

#ifdef _LP64

    return new_register(T_LONG);

#else

    return new_register(T_INT);

#endif

  }

  static LIR_Condition lir_cond(If::Condition cond) {

    LIR_Condition l;

    switch (cond) {

    case If::eql: l = lir_cond_equal;        break;

    case If::neq: l = lir_cond_notEqual;     break;

    case If::lss: l = lir_cond_less;         break;

    case If::leq: l = lir_cond_lessEqual;    break;

    case If::geq: l = lir_cond_greaterEqual; break;

    case If::gtr: l = lir_cond_greater;      break;

    };

    return l;

  }

  void init();

  SwitchRangeArray* create_lookup_ranges(TableSwitch* x);

  SwitchRangeArray* create_lookup_ranges(LookupSwitch* x);

  void do_SwitchRanges(SwitchRangeArray* x, LIR_Opr value, BlockBegin* default_sux);

 public:

  Compilation*  compilation() const              { return _compilation; }

  FrameMap*     frame_map() const                { return _compilation->frame_map(); }

  ciMethod*     method() const                   { return _method; }

  BlockBegin*   block() const                    { return _block; }

  IRScope*      scope() const                    { return block()->scope(); }

  int max_virtual_register_number() const        { return _virtual_register_number; }

  void block_do(BlockBegin* block);

  // Flags that can be set on vregs

  enum VregFlag {

      must_start_in_memory = 0  // needs to be assigned a memory location at beginning, but may then be loaded in a register

    , callee_saved     = 1    // must be in a callee saved register

    , byte_reg         = 2    // must be in a byte register

    , num_vreg_flags

  };

  LIRGenerator(Compilation* compilation, ciMethod* method)

    : _compilation(compilation)

    , _method(method)

    , _virtual_register_number(LIR_OprDesc::vreg_base)

    , _vreg_flags(NULL, 0, num_vreg_flags) {

    init();

  }

  // for virtual registers, maps them back to Phi's or Local's

  Instruction* instruction_for_opr(LIR_Opr opr);

  Instruction* instruction_for_vreg(int reg_num);

  void set_vreg_flag   (int vreg_num, VregFlag f);

  bool is_vreg_flag_set(int vreg_num, VregFlag f);

  void set_vreg_flag   (LIR_Opr opr,  VregFlag f) { set_vreg_flag(opr->vreg_number(), f); }

  bool is_vreg_flag_set(LIR_Opr opr,  VregFlag f) { return is_vreg_flag_set(opr->vreg_number(), f); }

  // statics

  static LIR_Opr exceptionOopOpr();

  static LIR_Opr exceptionPcOpr();

  static LIR_Opr divInOpr();

  static LIR_Opr divOutOpr();

  static LIR_Opr remOutOpr();

  static LIR_Opr shiftCountOpr();

  LIR_Opr syncTempOpr();

  // returns a register suitable for saving the thread in a

  // call_runtime_leaf if one is needed.

  LIR_Opr getThreadTemp();

  // visitor functionality

  virtual void do_Phi            (Phi*             x);

  virtual void do_Local          (Local*           x);

  virtual void do_Constant       (Constant*        x);

  virtual void do_LoadField      (LoadField*       x);

  virtual void do_StoreField     (StoreField*      x);

  virtual void do_ArrayLength    (ArrayLength*     x);

  virtual void do_LoadIndexed    (LoadIndexed*     x);

  virtual void do_StoreIndexed   (StoreIndexed*    x);

  virtual void do_NegateOp       (NegateOp*        x);

  virtual void do_ArithmeticOp   (ArithmeticOp*    x);

  virtual void do_ShiftOp        (ShiftOp*         x);

  virtual void do_LogicOp        (LogicOp*         x);

  virtual void do_CompareOp      (CompareOp*       x);

  virtual void do_IfOp           (IfOp*            x);

  virtual void do_Convert        (Convert*         x);

  virtual void do_NullCheck      (NullCheck*       x);

  virtual void do_Invoke         (Invoke*          x);

  virtual void do_NewInstance    (NewInstance*     x);

  virtual void do_NewTypeArray   (NewTypeArray*    x);

  virtual void do_NewObjectArray (NewObjectArray*  x);

  virtual void do_NewMultiArray  (NewMultiArray*   x);

  virtual void do_CheckCast      (CheckCast*       x);

  virtual void do_InstanceOf     (InstanceOf*      x);

  virtual void do_MonitorEnter   (MonitorEnter*    x);

  virtual void do_MonitorExit    (MonitorExit*     x);

  virtual void do_Intrinsic      (Intrinsic*       x);

  virtual void do_BlockBegin     (BlockBegin*      x);

  virtual void do_Goto           (Goto*            x);

  virtual void do_If             (If*              x);

  virtual void do_IfInstanceOf   (IfInstanceOf*    x);

  virtual void do_TableSwitch    (TableSwitch*     x);

  virtual void do_LookupSwitch   (LookupSwitch*    x);

  virtual void do_Return         (Return*          x);

  virtual void do_Throw          (Throw*           x);

  virtual void do_Base           (Base*            x);

  virtual void do_OsrEntry       (OsrEntry*        x);

  virtual void do_ExceptionObject(ExceptionObject* x);

  virtual void do_RoundFP        (RoundFP*         x);

  virtual void do_UnsafeGetRaw   (UnsafeGetRaw*    x);

  virtual void do_UnsafePutRaw   (UnsafePutRaw*    x);

  virtual void do_UnsafeGetObject(UnsafeGetObject* x);

  virtual void do_UnsafePutObject(UnsafePutObject* x);

  virtual void do_UnsafePrefetchRead (UnsafePrefetchRead*  x);

  virtual void do_UnsafePrefetchWrite(UnsafePrefetchWrite* x);

  virtual void do_ProfileCall    (ProfileCall*     x);

  virtual void do_ProfileCounter (ProfileCounter*  x);

};

class LIRItem: public CompilationResourceObj {

 private:

  Value         _value;

  LIRGenerator* _gen;

  LIR_Opr       _result;

  bool          _destroys_register;

  LIR_Opr       _new_result;

  LIRGenerator* gen() const { return _gen; }

 public:

  LIRItem(Value value, LIRGenerator* gen) {

    _destroys_register = false;

    _gen = gen;

    set_instruction(value);

  }

  LIRItem(LIRGenerator* gen) {

    _destroys_register = false;

    _gen = gen;

    _result = LIR_OprFact::illegalOpr;

    set_instruction(NULL);

  }

  void set_instruction(Value value) {

    _value = value;