lopcodes.h
(5.0.3)
/*
** $Id: lopcodes.h,v 1.102 2002/08/21 18:56:09 roberto Exp $
** 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
`B' : 9 bits
`C' : 9 bits
`Bx' : 18 bits (`B' and `C' together)
`sBx' : signed Bx
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, iABx, iAsBx}; /* basic instruction format */
/*
** size and position of opcode arguments.
*/
#define SIZE_C 9
#define SIZE_B 9
#define SIZE_Bx (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_Bx 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_Bx < BITS_INT-1
#define MAXARG_Bx ((1<<SIZE_Bx)-1)
#define MAXARG_sBx (MAXARG_Bx>>1) /* `sBx' is signed */
#else
#define MAXARG_Bx MAX_INT
#define MAXARG_sBx 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) (cast(OpCode, (i)&MASK1(SIZE_OP,0)))
#define SET_OPCODE(i,o) ((i) = (((i)&MASK0(SIZE_OP,0)) | cast(Instruction, o)))
#define GETARG_A(i) (cast(int, (i)>>POS_A))
#define SETARG_A(i,u) ((i) = (((i)&MASK0(SIZE_A,POS_A)) | \
((cast(Instruction, u)<<POS_A)&MASK1(SIZE_A,POS_A))))
#define GETARG_B(i) (cast(int, ((i)>>POS_B) & MASK1(SIZE_B,0)))
#define SETARG_B(i,b) ((i) = (((i)&MASK0(SIZE_B,POS_B)) | \
((cast(Instruction, b)<<POS_B)&MASK1(SIZE_B,POS_B))))
#define GETARG_C(i) (cast(int, ((i)>>POS_C) & MASK1(SIZE_C,0)))
#define SETARG_C(i,b) ((i) = (((i)&MASK0(SIZE_C,POS_C)) | \
((cast(Instruction, b)<<POS_C)&MASK1(SIZE_C,POS_C))))
#define GETARG_Bx(i) (cast(int, ((i)>>POS_Bx) & MASK1(SIZE_Bx,0)))
#define SETARG_Bx(i,b) ((i) = (((i)&MASK0(SIZE_Bx,POS_Bx)) | \
((cast(Instruction, b)<<POS_Bx)&MASK1(SIZE_Bx,POS_Bx))))
#define GETARG_sBx(i) (GETARG_Bx(i)-MAXARG_sBx)
#define SETARG_sBx(i,b) SETARG_Bx((i),cast(unsigned int, (b)+MAXARG_sBx))
#define CREATE_ABC(o,a,b,c) (cast(Instruction, o) \
| (cast(Instruction, a)<<POS_A) \
| (cast(Instruction, b)<<POS_B) \
| (cast(Instruction, c)<<POS_C))
#define CREATE_ABx(o,a,bc) (cast(Instruction, o) \
| (cast(Instruction, a)<<POS_A) \
| (cast(Instruction, bc)<<POS_Bx))
/*
** invalid register that fits in 8 bits
*/
#define NO_REG MAXARG_A
/*
** R(x) - register
** Kst(x) - constant (in constant table)
** RK(x) == if x < MAXSTACK then R(x) else Kst(x-MAXSTACK)
*/
/*
** grep "ORDER OP" if you change these enums
*/
typedef enum {
/*----------------------------------------------------------------------
name args description
------------------------------------------------------------------------*/
OP_MOVE,/* A B R(A) := R(B) */
OP_LOADK,/* A Bx R(A) := Kst(Bx) */
OP_LOADBOOL,/* A B C R(A) := (Bool)B; if (C) PC++ */
OP_LOADNIL,/* A B R(A) := ... := R(B) := nil */
OP_GETUPVAL,/* A B R(A) := UpValue[B] */
OP_GETGLOBAL,/* A Bx R(A) := Gbl[Kst(Bx)] */
OP_GETTABLE,/* A B C R(A) := R(B)[RK(C)] */
OP_SETGLOBAL,/* A Bx Gbl[Kst(Bx)] := R(A) */
OP_SETUPVAL,/* A B UpValue[B] := R(A) */
OP_SETTABLE,/* A B C R(A)[RK(B)] := RK(C) */
OP_NEWTABLE,/* A B C R(A) := {} (size = B,C) */
OP_SELF,/* A B C R(A+1) := R(B); R(A) := R(B)[RK(C)] */
OP_ADD,/* A B C R(A) := RK(B) + RK(C) */
OP_SUB,/* A B C R(A) := RK(B) - RK(C) */
OP_MUL,/* A B C R(A) := RK(B) * RK(C) */
OP_DIV,/* A B C R(A) := RK(B) / RK(C) */
OP_POW,/* A B C R(A) := RK(B) ^ RK(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,/* sBx PC += sBx */
OP_EQ,/* A B C if ((RK(B) == RK(C)) ~= A) then pc++ */
OP_LT,/* A B C if ((RK(B) < RK(C)) ~= A) then pc++ */
OP_LE,/* A B C if ((RK(B) <= RK(C)) ~= A) then pc++ */
OP_TEST,/* A B C if (R(B) <=> C) then R(A) := R(B) else pc++ */
OP_CALL,/* A B C R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */
OP_TAILCALL,/* A B C return R(A)(R(A+1), ... ,R(A+B-1)) */
OP_RETURN,/* A B return R(A), ... ,R(A+B-2) (see note) */
OP_FORLOOP,/* A sBx R(A)+=R(A+2); if R(A) <?= R(A+1) then PC+= sBx */
OP_TFORLOOP,/* A C R(A+2), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2));
if R(A+2) ~= nil then pc++ */
OP_TFORPREP,/* A sBx if type(R(A)) == table then R(A+1):=R(A), R(A):=next;
PC += sBx */
OP_SETLIST,/* A Bx R(A)[Bx-Bx%FPF+i] := R(A+i), 1 <= i <= Bx%FPF+1 */
OP_SETLISTO,/* A Bx */
OP_CLOSE,/* A close all variables in the stack up to (>=) R(A)*/
OP_CLOSURE/* A Bx R(A) := closure(KPROTO[Bx], R(A), ... ,R(A+n)) */
} OpCode;
#define NUM_OPCODES (cast(int, OP_CLOSURE+1))
/*===========================================================================
Notes:
(1) In OP_CALL, if (B == 0) then B = top. C is the number of returns - 1,
and can be 0: OP_CALL then sets `top' to last_result+1, so
next open instruction (OP_CALL, OP_RETURN, OP_SETLIST) may use `top'.
(2) In OP_RETURN, if (B == 0) then return up to `top'
(3) For comparisons, B specifies what conditions the test should accept.
(4) All `skips' (pc++) assume that next instruction is a jump
===========================================================================*/
/*
** masks for instruction properties
*/
enum OpModeMask {
OpModeBreg = 2, /* B is a register */
OpModeBrk, /* B is a register/constant */
OpModeCrk, /* C is a register/constant */
OpModesetA, /* instruction set register A */
OpModeK, /* Bx is a constant */
OpModeT /* operator is a test */
};
extern const lu_byte luaP_opmodes[NUM_OPCODES];
#define getOpMode(m) (cast(enum OpMode, luaP_opmodes[m] & 3))
#define testOpMode(m, b) (luaP_opmodes[m] & (1 << (b)))
#ifdef LUA_OPNAMES
extern const char *const luaP_opnames[]; /* opcode names */
#endif
/* number of list items to accumulate before a SETLIST instruction */
/* (must be a power of 2) */
#define LFIELDS_PER_FLUSH 32
#endif