/*

 * Copyright 1997-2007 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.

 *

 */

 public:

  // Sentinel placed in the code for interpreter returns so

  // that i2c adapters and osr code can recognize an interpreter

  // return address and convert the return to a specialized

  // block of code to handle compiedl return values and cleaning

  // the fpu stack.

  static const int return_sentinel;

  static Address::ScaleFactor stackElementScale() {

    return TaggedStackInterpreter? Address::times_8 : Address::times_4;

  }

  // Offset from rsp (which points to the last stack element)

  static int expr_offset_in_bytes(int i) { return stackElementSize()*i ; }

  static int expr_tag_offset_in_bytes(int i) {

    assert(TaggedStackInterpreter, "should not call this");

    return expr_offset_in_bytes(i) + wordSize;

  }

  // Support for Tagged Stacks

  // Stack index relative to tos (which points at value)

  static int expr_index_at(int i)     {

    return stackElementWords() * i;

  }

  static int expr_tag_index_at(int i) {

    assert(TaggedStackInterpreter, "should not call this");

    // tag is one word above java stack element

    return stackElementWords() * i + 1;

  }

  // Already negated by c++ interpreter

  static int local_index_at(int i)     {

    assert(i<=0, "local direction already negated");

    return stackElementWords() * i + (value_offset_in_bytes()/wordSize);

  }

  static int local_tag_index_at(int i) {

    assert(i<=0, "local direction already negated");

    assert(TaggedStackInterpreter, "should not call this");

    return stackElementWords() * i + (tag_offset_in_bytes()/wordSize);

  }