/*
 * @(#)Machine.java                        2.0 1999/08/11
 *
 * Copyright (C) 1999 D.A. Watt and D.F. Brown
 * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
 * and School of Computer and Math Sciences, The Robert Gordon University,
 * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
 * All rights reserved.
 *
 * This software is provided free for educational use only. It may
 * not be used for commercial purposes without the prior written permission
 * of the authors.
 */

package TAM;

public final class Machine {


  public final static int
    maxRoutineLevel = 7;

// WORDS AND ADDRESSES

// Java has no type synonyms, so the following representations are
// assumed:
//
//  type
//    Word = -32767..+32767; {16 bits signed}
//    DoubleWord = -2147483648..+2147483647; {32 bits signed}
//    CodeAddress = 0..+32767; {15 bits unsigned}
//    DataAddress = 0..+32767; {15 bits unsigned}


// INSTRUCTIONS

  // Operation codes
  public final static int
    LOADop = 0,
    LOADAop = 1,
    LOADIop = 2,
    LOADLop = 3,
    STOREop = 4,
    STOREIop = 5,
    CALLop = 6,
    CALLIop = 7,
    RETURNop = 8,
    PUSHop = 10,
    POPop = 11,
    JUMPop = 12,
    JUMPIop = 13,
    JUMPIFop = 14,
    HALTop = 15;



// CODE STORE

  public static Instruction[] code = new Instruction[1024];


// CODE STORE REGISTERS

  public final static int
    CB = 0,
    PB = 1024,  // = upper bound of code array + 1
    PT = 1052;  // = PB + 28

// REGISTER NUMBERS

  public final static int
    CBr = 0,
    CTr = 1,
    PBr = 2,
    PTr = 3,
    SBr = 4,
    STr = 5,
    HBr = 6,
    HTr = 7,
    LBr = 8,
    L1r = LBr + 1,
    L2r = LBr + 2,
    L3r = LBr + 3,
    L4r = LBr + 4,
    L5r = LBr + 5,
    L6r = LBr + 6,
    CPr = 15;


// DATA REPRESENTATION

  public final static int
    booleanSize = 1,
    characterSize = 1,
    integerSize = 1,
    addressSize = 1,
    closureSize = 2 * addressSize,

    linkDataSize = 3 * addressSize,

    falseRep = 0,
    trueRep = 1,
    maxintRep = 32767;


// ADDRESSES OF PRIMITIVE ROUTINES

  public final static int
    idDisplacement = 1,
    notDisplacement = 2,
    andDisplacement = 3,
    orDisplacement = 4,
    succDisplacement = 5,
    predDisplacement = 6,
    negDisplacement = 7,
    addDisplacement = 8,
    subDisplacement = 9,
    multDisplacement = 10,
    divDisplacement = 11,
    modDisplacement = 12,
    ltDisplacement = 13,
    leDisplacement = 14,
    geDisplacement = 15,
    gtDisplacement = 16,
    eqDisplacement = 17,
    neDisplacement = 18,
    eolDisplacement = 19,
    eofDisplacement = 20,
    getDisplacement = 21,
    putDisplacement = 22,
    geteolDisplacement = 23,
    puteolDisplacement = 24,
    getintDisplacement = 25,
    putintDisplacement = 26,
    newDisplacement = 27,
    disposeDisplacement = 28;

}
