/*

 * 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

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 */

#include "code/vmreg.hpp"

#include "opto/block.hpp"

#include "opto/matcher.hpp"

#include "opto/phase.hpp"

class Node;

class Matcher;

class PhaseCFG;

#define  MAX_REG_ALLOCATORS   10

//------------------------------PhaseRegAlloc------------------------------------

// Abstract register allocator

class PhaseRegAlloc : public Phase {

  friend class VMStructs;

  static void (*_alloc_statistics[MAX_REG_ALLOCATORS])();

  static int _num_allocators;

protected:

  OptoRegPair  *_node_regs;

  uint         _node_regs_max_index;

  VectorSet    _node_oops;         // Mapping from node indices to oopiness

  void alloc_node_regs(int size);  // allocate _node_regs table with at least "size" elements

  PhaseRegAlloc( uint unique, PhaseCFG &cfg, Matcher &matcher,

                 void (*pr_stats)());

public:

  PhaseCFG &_cfg;               // Control flow graph

  uint _framesize;              // Size of frame in stack-slots. not counting preserve area

  OptoReg::Name _max_reg;       // Past largest register seen

  Matcher &_matcher;            // Convert Ideal to MachNodes

  uint node_regs_max_index() const { return _node_regs_max_index; }

  // Get the register associated with the Node

  OptoReg::Name get_reg_first( const Node *n ) const {

    debug_only( if( n->_idx >= _node_regs_max_index ) n->dump(); );

    assert( n->_idx < _node_regs_max_index, "Exceeded _node_regs array");

    return _node_regs[n->_idx].first();

  }

  OptoReg::Name get_reg_second( const Node *n ) const {

    debug_only( if( n->_idx >= _node_regs_max_index ) n->dump(); );

    assert( n->_idx < _node_regs_max_index, "Exceeded _node_regs array");

    return _node_regs[n->_idx].second();

  }

  // Do all the real work of allocate

  virtual void Register_Allocate() = 0;

  // notify the register allocator that "node" is a new reference

  // to the value produced by "old_node"

  virtual void add_reference( const Node *node, const Node *old_node) = 0;

  // Set the register associated with a new Node

  void set_bad( uint idx ) {

    assert( idx < _node_regs_max_index, "Exceeded _node_regs array");

    _node_regs[idx].set_bad();

  }

  void set1( uint idx, OptoReg::Name reg ) {

    assert( idx < _node_regs_max_index, "Exceeded _node_regs array");

    _node_regs[idx].set1(reg);

  }

  void set2( uint idx, OptoReg::Name reg ) {

    assert( idx < _node_regs_max_index, "Exceeded _node_regs array");

    _node_regs[idx].set2(reg);

  }

  void set_pair( uint idx, OptoReg::Name hi, OptoReg::Name lo ) {

    assert( idx < _node_regs_max_index, "Exceeded _node_regs array");

    _node_regs[idx].set_pair(hi, lo);

  }

  void set_ptr( uint idx, OptoReg::Name reg ) {

    assert( idx < _node_regs_max_index, "Exceeded _node_regs array");

    _node_regs[idx].set_ptr(reg);

  }

  // Set and query if a node produces an oop

  void set_oop( const Node *n, bool );

  bool is_oop( const Node *n ) const;

  // Convert a register number to a stack offset

  int reg2offset          ( OptoReg::Name reg ) const;

  int reg2offset_unchecked( OptoReg::Name reg ) const;

  // Convert a stack offset to a register number

  OptoReg::Name offset2reg( int stk_offset ) const;

  // Get the register encoding associated with the Node

  int get_encode(const Node *n) const {

    assert( n->_idx < _node_regs_max_index, "Exceeded _node_regs array");

    OptoReg::Name first = _node_regs[n->_idx].first();

    OptoReg::Name second = _node_regs[n->_idx].second();

    assert( !OptoReg::is_valid(second) || second == first+1, "" );

    assert(OptoReg::is_reg(first), "out of range");

    return Matcher::_regEncode[first];

  }

#ifndef PRODUCT

  static int _total_framesize;

  static int _max_framesize;

  virtual void dump_frame() const = 0;

  virtual char *dump_register( const Node *n, char *buf  ) const = 0;

  static void print_statistics();

#endif

};