/*

 * Copyright (c) 2000, 2013, 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.

 *

 */

#include "precompiled.hpp"

#include "opto/regalloc.hpp"

static const int NodeRegsOverflowSize = 200;

void (*PhaseRegAlloc::_alloc_statistics[MAX_REG_ALLOCATORS])();

int PhaseRegAlloc::_num_allocators = 0;

#ifndef PRODUCT

int PhaseRegAlloc::_total_framesize = 0;

int PhaseRegAlloc::_max_framesize = 0;

#endif

PhaseRegAlloc::PhaseRegAlloc( uint unique, PhaseCFG &cfg,

                              Matcher &matcher,

                              void (*pr_stats)() ):

               Phase(Register_Allocation),

               _node_regs(0),

               _node_regs_max_index(0),

               _node_oops(Thread::current()->resource_area()),

               _cfg(cfg),

               _framesize(0xdeadbeef),

               _matcher(matcher)

{

    int i;

    for (i=0; i < _num_allocators; i++) {

        if (_alloc_statistics[i] == pr_stats)

            return;

    }

    assert((_num_allocators + 1) < MAX_REG_ALLOCATORS, "too many register allocators");

    _alloc_statistics[_num_allocators++] = pr_stats;

}

//------------------------------reg2offset-------------------------------------

int PhaseRegAlloc::reg2offset_unchecked( OptoReg::Name reg ) const {

  // Slots below _max_in_arg_stack_reg are offset by the entire frame.

  // Slots above _max_in_arg_stack_reg are frame_slots and are not offset.

  int slot = (reg < _matcher._new_SP)

    ? reg - OptoReg::stack0() + _framesize

    : reg - _matcher._new_SP;

  // Note:  We use the direct formula (reg - SharedInfo::stack0) instead of

  // OptoReg::reg2stack(reg), in order to avoid asserts in the latter

  // function.  This routine must remain unchecked, so that dump_frame()

  // can do its work undisturbed.

  // %%% not really clear why reg2stack would assert here

  return slot*VMRegImpl::stack_slot_size;

}

int PhaseRegAlloc::reg2offset( OptoReg::Name reg ) const {

  // Not allowed in the out-preserve area.

  // In-preserve area is allowed so Intel can fetch the return pc out.

  assert( reg <  _matcher._old_SP ||

          (reg >= OptoReg::add(_matcher._old_SP,C->out_preserve_stack_slots()) &&

           reg <  _matcher._in_arg_limit) ||

          reg >=  OptoReg::add(_matcher._new_SP, C->out_preserve_stack_slots()) ||

          // Allow return_addr in the out-preserve area.

          reg == _matcher.return_addr(),

          "register allocated in a preserve area" );

  return reg2offset_unchecked( reg );

}

//------------------------------offset2reg-------------------------------------

OptoReg::Name PhaseRegAlloc::offset2reg(int stk_offset) const {

  int slot = stk_offset / jintSize;

  int reg = (slot < (int) _framesize)

    ? slot + _matcher._new_SP

    : OptoReg::stack2reg(slot) - _framesize;

  assert(stk_offset == reg2offset((OptoReg::Name) reg),

         "offset2reg does not invert properly");

  return (OptoReg::Name) reg;

}

//------------------------------set_oop----------------------------------------

void PhaseRegAlloc::set_oop( const Node *n, bool is_an_oop ) {

  if( is_an_oop ) {

    _node_oops.set(n->_idx);

  }

}

//------------------------------is_oop-----------------------------------------

bool PhaseRegAlloc::is_oop( const Node *n ) const {

  return _node_oops.test(n->_idx) != 0;

}

// Allocate _node_regs table with at least "size" elements

void PhaseRegAlloc::alloc_node_regs(int size) {

  _node_regs_max_index = size + (size >> 1) + NodeRegsOverflowSize;

  _node_regs = NEW_RESOURCE_ARRAY( OptoRegPair, _node_regs_max_index );

  // We assume our caller will fill in all elements up to size-1, so

  // only the extra space we allocate is initialized here.

  for( uint i = size; i < _node_regs_max_index; ++i )

    _node_regs[i].set_bad();

}

#ifndef PRODUCT

void

PhaseRegAlloc::print_statistics() {

  tty->print_cr("Total frameslots = %d, Max frameslots = %d", _total_framesize, _max_framesize);

  int i;

  for (i=0; i < _num_allocators; i++) {

    _alloc_statistics[i]();

  }

}

#endif