#ifndef OPCODES_H
#define OPCODES_H

/*
 opcodes.h

 XIDEK: Extensible Script Language Development Kit
 Opcode Definitions

 Copyright (c) 1996-2002 Parsifal Software.
 All Rights Reserved.

 For further information about this program or the AnaGram
 parser generator, please contact:

    Parsifal Software
    http://www.parsifalsoft.com
    info@parsifalsoft.com
    +1-800-879-2577, Voice/Fax +1-508-358-2564
    P.O. Box 219
    Wayland, MA 01778
    USA
*/

// Virtual machine instruction list
// Caution! don't add entries to this list without making corresponding
// additions to const char *opcodeText[] in bcidefs.cpp
enum Opcode {
   // Opcodes with no operand; one byte-code-size long.
   HLT,          // Stop execution
   FETCH,        // Fetch value addressed by top stack element
   I_FETCH,      // Increment, then fetch value adressed by top of stack
   D_FETCH,      // Decrement, then fetch value adressed by top of stack
   FETCH_I,      // Fetch, then increment value addressed by top of stack
   FETCH_D,      // Fetch, then increment value addressed by top of stack
   STORE,        // pop top of stack, store indirect through lvalue that
                 // is next on stack and replace lvalue with the stored value
   POP,          // discard top element of stack
   SAP,          // Store and pop,
   PRINT,        // Pop top stack element and print it
   RETURN,

   // Binary operators: pop two values off stack, compute, push result
   ADD,          // Add
   SUB,          // Subtract
   MUL,          // Multiply
   DIV,          // Divide
   IDIV,         // Integer Divide
   RDIV,         // Real divide
   MOD,          // Remainder
   POW,          // Raise to power
   AND,          // And
   IOR,          // Inclusive or
   XOR,          // Exclusive or
   LS,           // Left shift
   RS,           // Right shift

   /*
    * Binary operators on memory:
    *   pop top stack element,
    *   pop pointer from stack
    *   fetch value through pointer
    *   compute,
    *   then push result and also store it through pointer
    */
   ADDM,         // Add to memory (variable)
   SUBM,         // Subtract from memory (variable)
   MULM,         // Multiply with memory (variable)
   DIVM,         // Divide by memory (variable)
   MODM,         // Remainder to memory
   ANDM,         // And to memory (variable)
   IORM,         // Inclusive or to memory (variable)
   XORM,         // Exclusive or to memory (variable)
   LSM,          // Left shift memory (variable)
   RSM,          // Right shift memory (variable)
   POWM,         // Raise memory to power

   // Comparison operators: pop two values off stack, push zero or nonzero
   LT,           // <
   LE,           // <=
   GT,           // >
   GE,           // >=
   EQ,           // ==
   NE,           // !=

   // Unary operators: pop value from stack, compute, push result
   NEG,          // Negate top element on stack
   NOT,          // Logical NOT of top element on stack
   COM,          // bitwise complement

   // Cast operators
   CAST_LONG,    // Make value long
   CAST_DOUBLE,  // Make value double

   /*
    * Opcodes with one operand; two byte-code-sizes long.
    * In the descriptions, the value of the operand is represented with "K".
    */

   LOCATE,       // Push address of variable no. K onto stack
   PUSHC,        // Push value of constant no. K onto stack
   DUMP,         // Print name and value of variable no. K.

   /*
    Branch instructions: K is the offset in number of bytecodes
    relative to the address of the instruction after the branch instruction.
    That is, BR -2 is an infinite loop.
   */
   LAND,         // branch on false; pop top stack element if not taken
   LOR,          // branch on true; pop top stack element if not taken
   BR,           // branch unconditionally
   BRF,          // branch on false, always pop top stack element
   BRT,          // branch on true, always pop top stack element
   CALL,         // call K'th function in function table
   RPT,          // repeat block n times
};

#endif