/*
 * Copyright 2000-2001 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.
 *  
 */

package sun.jvm.hotspot.asm.sparc;

import sun.jvm.hotspot.asm.*;
import sun.jvm.hotspot.utilities.*;

/** SPARCArgument is an abstraction used to represent an outgoing
    actual argument or an incoming formal parameter, whether it
    resides in memory or in a register, in a manner consistent with
    the SPARC Application Binary Interface, or ABI.  This is often
    referred to as the native or C calling convention. */

public class SPARCArgument {
  private int     number;
  private boolean isIn;

  // FIXME: add 64-bit stuff here (support for FP registers)
  
  /** Only 6 registers may contain integer parameters */
  public static final int NUM_REGISTER_PARAMETERS = 6;
  
  public SPARCArgument(int number, boolean isIn) {
    this.number = number;
    this.isIn   = isIn;
  }

  int     getNumber() { return number;     }
  boolean getIsIn()   { return isIn;       }
  boolean getIsOut()  { return !getIsIn(); }

  public SPARCArgument getSuccessor() { return new SPARCArgument(getNumber() + 1, getIsIn()); }
  public SPARCArgument asIn()         { return new SPARCArgument(getNumber(),     true);      }
  public SPARCArgument asOut()        { return new SPARCArgument(getNumber(),     false);     }

  /** Locating register-based arguments */
  public boolean isRegister()         { return number < NUM_REGISTER_PARAMETERS; }

  public SPARCRegister asRegister() {
    if (Assert.ASSERTS_ENABLED) {
      Assert.that(isRegister(), "must be a register argument");
    }
    return new SPARCRegister(getIsIn() ? SPARCRegisterType.IN : SPARCRegisterType.OUT, getNumber());
  }

  // locating memory-based arguments (FIXME: elided for now, will
  // necessitate creating new SPARCAddress class)
  //  public SPARCAddress asAddress() {
  //    if (Assert.ASSERTS_ENABLED) {
  //      Assert.that(!isRegister(), "must be a memory argument");
  //    }
  //    return addressInFrame();
  //  }
  //
  //  /** When applied to a register-based argument, give the corresponding address
  //      into the 6-word area "into which callee may store register arguments"
  //      (This is a different place than the corresponding register-save area location.)  */
  //  public SPARCAddress addressInFrame() const {
  //    return SPARCAddress( is_in()   ? Address::extra_in_argument 
  //		  	      : Address::extra_out_argument,
  //	            _number );
  //  }
}
