/*
** $Id: lopcodes.h,v 1.76 2001/06/28 19:58:57 roberto Exp roberto $
** Opcodes for Lua virtual machine
** See Copyright Notice in lua.h
*/
#ifndef lopcodes_h
#define lopcodes_h
#include "llimits.h"
/*===========================================================================
We assume that instructions are unsigned numbers.
All instructions have an opcode in the first 6 bits.
Instructions can have the following fields:
`A' : 8 bits (25-32)
`B' : 8 bits (17-24)
`C' : 10 bits (7-16)
`Bc' : 18 bits (`B' and `C' together)
`sBc' : signed Bc
A signed argument is represented in excess K; that is, the number
value is the unsigned value minus K. K is exactly the maximum value
for that argument (so that -max is represented by 0, and +max is
represented by 2*max), which is half the maximum for the corresponding
unsigned argument.
===========================================================================*/
enum OpMode {iABC, iABc, iAsBc}; /* basic instruction format */
/*
** size and position of opcode arguments.
*/
#define SIZE_C 10
#define SIZE_B 8
#define SIZE_Bc (SIZE_C + SIZE_B)
#define SIZE_A 8
#define SIZE_OP 6
#define POS_C SIZE_OP
#define POS_B (POS_C + SIZE_C)
#define POS_Bc POS_C
#define POS_A (POS_B + SIZE_B)
/*
** limits for opcode arguments.
** we use (signed) int to manipulate most arguments,
** so they must fit in BITS_INT-1 bits (-1 for sign)
*/
#if SIZE_Bc < BITS_INT-1
#define MAXARG_Bc ((1<<SIZE_Bc)-1)
#define MAXARG_sBc (MAXARG_Bc>>1) /* `sBc' is signed */
#else
#define MAXARG_Bc MAX_INT
#define MAXARG_sBc MAX_INT
#endif
#define MAXARG_A ((1<<SIZE_A)-1)
#define MAXARG_B ((1<<SIZE_B)-1)
#define MAXARG_C ((1<<SIZE_C)-1)
/* creates a mask with `n' 1 bits at position `p' */
#define MASK1(n,p) ((~((~(Instruction)0)<<n))<<p)
/* creates a mask with `n' 0 bits at position `p' */
#define MASK0(n,p) (~MASK1(n,p))
/*
** the following macros help to manipulate instructions
*/
#define GET_OPCODE(i) ((OpCode)((i)&MASK1(SIZE_OP,0)))
#define SET_OPCODE(i,o) (((i)&MASK0(SIZE_OP,0)) | (Instruction)(o))
#define GETARG_A(i) ((int)((i)>>POS_A))
#define SETARG_A(i,u) ((i) = (((i)&MASK0(SIZE_A,POS_A)) | \
((Instruction)(u)<<POS_A)))
#define GETARG_B(i) ((int)(((i)>>POS_B) & MASK1(SIZE_B,0)))
#define SETARG_B(i,b) ((i) = (((i)&MASK0(SIZE_B,POS_B)) | \
((Instruction)(b)<<POS_B)))
#define GETARG_C(i) ((int)(((i)>>POS_C) & MASK1(SIZE_C,0)))
#define SETARG_C(i,b) ((i) = (((i)&MASK0(SIZE_C,POS_C)) | \
((Instruction)(b)<<POS_C)))
#define GETARG_Bc(i) ((int)(((i)>>POS_Bc) & MASK1(SIZE_Bc,0)))
#define SETARG_Bc(i,b) ((i) = (((i)&MASK0(SIZE_Bc,POS_Bc)) | \
((Instruction)(b)<<POS_Bc)))
#define GETARG_sBc(i) (GETARG_Bc(i)-MAXARG_sBc)
#define SETARG_sBc(i,b) SETARG_Bc((i),(b)+MAXARG_sBc)
#define CREATE_ABC(o,a,b,c) ((Instruction)(o) \
| ((Instruction)(a)<<POS_A) \
| ((Instruction)(b)<<POS_B) \
| ((Instruction)(c)<<POS_C))
#define CREATE_ABc(o,a,bc) ((Instruction)(o) \
| ((Instruction)(a)<<POS_A) \
| ((Instruction)(bc)<<POS_Bc))
/*
** an invalid register that fits in 8 bits
*/
#define NO_REG MAXARG_A
/*
** R(x) - register
** Kst(x) - constant (in constant table)
** R/K(x) == if x < MAXSTACK then R(x) else Kst(x-MAXSTACK)
*/
typedef enum {
/*----------------------------------------------------------------------
name args description
------------------------------------------------------------------------*/
OP_MOVE,/* A B R(A) := R(B) */
OP_LOADK,/* A Bc R(A) := Kst(Bc) */
OP_LOADINT,/* A sBc R(A) := (Number)sBc */
OP_LOADNIL,/* A B R(A) := ... := R(B) := nil */
OP_LOADUPVAL,/* A Bc R(A) := UpValue[Bc] */
OP_GETGLOBAL,/* A Bc R(A) := Gbl[Kst(Bc)] */
OP_GETTABLE,/* A B C R(A) := R(B)[R/K(C)] */
OP_SETGLOBAL,/* A Bc Gbl[Kst(Bc)] := R(A) */
OP_SETTABLE,/* A B C R(B)[R/K(C)] := R(A) */
OP_NEWTABLE,/* A Bc R(A) := {} (size = Bc) */
OP_SELF,/* A B C R(A+1) := R(B); R(A) := R(B)[R/K(C)] */
OP_ADD,/* A B C R(A) := R(B) + R/K(C) */
OP_SUB,/* A B C R(A) := R(B) - R/K(C) */
OP_MUL,/* A B C R(A) := R(B) * R/K(C) */
OP_DIV,/* A B C R(A) := R(B) / R/K(C) */
OP_POW,/* A B C R(A) := R(B) ^ R/K(C) */
OP_UNM,/* A B R(A) := -R(B) */
OP_NOT,/* A B R(A) := not R(B) */
OP_CONCAT,/* A B C R(A) := R(B).. ... ..R(C) */
OP_JMP,/* sBc PC += sBc */
OP_CJMP,/* sBc if test then PC += sBc (see (1)) */
OP_TESTEQ,/* A C test := (R(A) == R/K(C)) */
OP_TESTNE,/* A C test := (R(A) ~= R/K(C)) */
OP_TESTLT,/* A C test := (R(A) < R/K(C)) */
OP_TESTLE,/* A C test := (R(A) <= R/K(C)) */
OP_TESTGT,/* A C test := (R(A) > R/K(C)) */
OP_TESTGE,/* A C test := (R(A) >= R/K(C)) */
OP_TESTT,/* A B test := R(B); if (test) R(A) := R(B) */
OP_TESTF,/* A B test := not R(B); if (test) R(A) := nil */
OP_NILJMP,/* A Bc R(A) := nil; PC++; */
OP_CALL,/* A B C R(A), ... ,R(A+C-1) := R(A)(R(A+1), ... ,R(A+B))*/
OP_RETURN,/* A B return R(A), ... ,R(A+B-1) (see (3)) */
OP_FORPREP,/* A sBc */
OP_FORLOOP,/* A sBc */
OP_TFORPREP,/* A sBc */
OP_TFORLOOP,/* A sBc */
OP_SETLIST,/* A Bc R(A)[Bc-Bc%FPF+i] := R(A+i), 1 <= i <= Bc%FPF+1 */
OP_SETLISTO,/* A Bc */
OP_CLOSURE /* A Bc R(A) := closure(KPROTO[Bc], R(A), ... ,R(A+n)) */
} OpCode;
#define NUM_OPCODES ((int)OP_CLOSURE+1)
/*===========================================================================
Notes:
(1) In the current implementation there is no `test' variable;
instructions OP_TEST* and OP_CJMP must always occur together.
(2) In OP_CALL, if (B == NO_REG) then B = top. C is the number of returns,
and can be NO_REG. OP_CALL can set `top' to last_result+1, so
next open instruction (OP_CALL, OP_RETURN, OP_SETLIST) may use `top'.
(3) In OP_RETURN, if (B == NO_REG) then return up to `top'
===========================================================================*/
/*
** masks for instruction properties
*/
enum OpModeMask {
OpModeBreg = 2, /* B is a register */
OpModeCreg, /* C is a register/constant */
OpModesetA, /* instruction set register A */
OpModeK, /* Bc is a constant */
OpModeT /* operator is a test */
};
extern const lu_byte luaP_opmodes[];
#define getOpMode(m) ((enum OpMode)(luaP_opmodes[m] & 3))
#define testOpMode(m, b) (luaP_opmodes[m] & (1 << (b)))
/*
** opcode names (only included when compiled with LUA_OPNAMES)
*/
extern const l_char *const luaP_opnames[];
#endif