lopcodes.h

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/*
** $Id: lopcodes.h $
** 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 32-bit integers.
  All instructions have an opcode in the first 7 bits.
  Instructions can have the following formats:
 
        3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0
        1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
iABC          C(8)     |      B(8)     |k|     A(8)      |   Op(7)     |
iABx                Bx(17)               |     A(8)      |   Op(7)     |
iAsBx              sBx (signed)(17)      |     A(8)      |   Op(7)     |
iAx                           Ax(25)                     |   Op(7)     |
isJ                           sJ(25)                     |   Op(7)     |
 
  A signed argument is represented in excess K: the represented value is
  the written unsigned value minus K, where K is half the maximum for the
  corresponding unsigned argument.
===========================================================================*/
 
 
enum OpMode {iABC, iABx, iAsBx, iAx, isJ};  /* basic instruction formats */
 
 
/*
** size and position of opcode arguments.
*/
#define SIZE_C      8
#define SIZE_B      8
#define SIZE_Bx     (SIZE_C + SIZE_B + 1)
#define SIZE_A      8
#define SIZE_Ax     (SIZE_Bx + SIZE_A)
#define SIZE_sJ     (SIZE_Bx + SIZE_A)
 
#define SIZE_OP     7
 
#define POS_OP      0
 
#define POS_A       (POS_OP + SIZE_OP)
#define POS_k       (POS_A + SIZE_A)
#define POS_B       (POS_k + 1)
#define POS_C       (POS_B + SIZE_B)
 
#define POS_Bx      POS_k
 
#define POS_Ax      POS_A
 
#define POS_sJ      POS_A
 
 
/*
** limits for opcode arguments.
** we use (signed) 'int' to manipulate most arguments,
** so they must fit in ints.
*/
 
/* Check whether type 'int' has at least 'b' bits ('b' < 32) */
#define L_INTHASBITS(b)     ((UINT_MAX >> ((b) - 1)) >= 1)
 
 
#if L_INTHASBITS(SIZE_Bx)
#define MAXARG_Bx   ((1<<SIZE_Bx)-1)
#else
#define MAXARG_Bx   MAX_INT
#endif
 
#define OFFSET_sBx  (MAXARG_Bx>>1)         /* 'sBx' is signed */
 
 
#if L_INTHASBITS(SIZE_Ax)
#define MAXARG_Ax   ((1<<SIZE_Ax)-1)
#else
#define MAXARG_Ax   MAX_INT
#endif
 
#if L_INTHASBITS(SIZE_sJ)
#define MAXARG_sJ   ((1 << SIZE_sJ) - 1)
#else
#define MAXARG_sJ   MAX_INT
#endif
 
#define OFFSET_sJ   (MAXARG_sJ >> 1)
 
 
#define MAXARG_A    ((1<<SIZE_A)-1)
#define MAXARG_B    ((1<<SIZE_B)-1)
#define MAXARG_C    ((1<<SIZE_C)-1)
#define OFFSET_sC   (MAXARG_C >> 1)
 
#define int2sC(i)   ((i) + OFFSET_sC)
#define sC2int(i)   ((i) - OFFSET_sC)
 
 
/* 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)>>POS_OP) & MASK1(SIZE_OP,0)))
#define SET_OPCODE(i,o) ((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \
        ((cast(Instruction, o)<<POS_OP)&MASK1(SIZE_OP,POS_OP))))
 
#define checkopm(i,m)   (getOpMode(GET_OPCODE(i)) == m)
 
 
#define getarg(i,pos,size)  (cast_int(((i)>>(pos)) & MASK1(size,0)))
#define setarg(i,v,pos,size)    ((i) = (((i)&MASK0(size,pos)) | \
                ((cast(Instruction, v)<<pos)&MASK1(size,pos))))
 
#define GETARG_A(i) getarg(i, POS_A, SIZE_A)
#define SETARG_A(i,v)   setarg(i, v, POS_A, SIZE_A)
 
#define GETARG_B(i) check_exp(checkopm(i, iABC), getarg(i, POS_B, SIZE_B))
#define GETARG_sB(i)    sC2int(GETARG_B(i))
#define SETARG_B(i,v)   setarg(i, v, POS_B, SIZE_B)
 
#define GETARG_C(i) check_exp(checkopm(i, iABC), getarg(i, POS_C, SIZE_C))
#define GETARG_sC(i)    sC2int(GETARG_C(i))
#define SETARG_C(i,v)   setarg(i, v, POS_C, SIZE_C)
 
#define TESTARG_k(i)    check_exp(checkopm(i, iABC), (cast_int(((i) & (1u << POS_k)))))
#define GETARG_k(i) check_exp(checkopm(i, iABC), getarg(i, POS_k, 1))
#define SETARG_k(i,v)   setarg(i, v, POS_k, 1)
 
#define GETARG_Bx(i)    check_exp(checkopm(i, iABx), getarg(i, POS_Bx, SIZE_Bx))
#define SETARG_Bx(i,v)  setarg(i, v, POS_Bx, SIZE_Bx)
 
#define GETARG_Ax(i)    check_exp(checkopm(i, iAx), getarg(i, POS_Ax, SIZE_Ax))
#define SETARG_Ax(i,v)  setarg(i, v, POS_Ax, SIZE_Ax)
 
#define GETARG_sBx(i)  \
    check_exp(checkopm(i, iAsBx), getarg(i, POS_Bx, SIZE_Bx) - OFFSET_sBx)
#define SETARG_sBx(i,b) SETARG_Bx((i),cast_uint((b)+OFFSET_sBx))
 
#define GETARG_sJ(i)  \
    check_exp(checkopm(i, isJ), getarg(i, POS_sJ, SIZE_sJ) - OFFSET_sJ)
#define SETARG_sJ(i,j) \
    setarg(i, cast_uint((j)+OFFSET_sJ), POS_sJ, SIZE_sJ)
 
 
#define CREATE_ABCk(o,a,b,c,k)  ((cast(Instruction, o)<<POS_OP) \
            | (cast(Instruction, a)<<POS_A) \
            | (cast(Instruction, b)<<POS_B) \
            | (cast(Instruction, c)<<POS_C) \
            | (cast(Instruction, k)<<POS_k))
 
#define CREATE_ABx(o,a,bc)  ((cast(Instruction, o)<<POS_OP) \
            | (cast(Instruction, a)<<POS_A) \
            | (cast(Instruction, bc)<<POS_Bx))
 
#define CREATE_Ax(o,a)      ((cast(Instruction, o)<<POS_OP) \
            | (cast(Instruction, a)<<POS_Ax))
 
#define CREATE_sJ(o,j,k)    ((cast(Instruction, o) << POS_OP) \
            | (cast(Instruction, j) << POS_sJ) \
            | (cast(Instruction, k) << POS_k))
 
 
#if !defined(MAXINDEXRK)  /* (for debugging only) */
#define MAXINDEXRK  MAXARG_B
#endif
 
 
/*
** invalid register that fits in 8 bits
*/
#define NO_REG      MAXARG_A
 
 
/*
** R[x] - register
** K[x] - constant (in constant table)
** RK(x) == if k(i) then K[x] else R[x]
*/
 
 
/*
** grep "ORDER OP" if you change these enums
*/
 
typedef enum {
/*----------------------------------------------------------------------
  name      args    description
------------------------------------------------------------------------*/
OP_MOVE,/*  A B R[A] := R[B]                    */
OP_LOADI,/* A sBx   R[A] := sBx                 */
OP_LOADF,/* A sBx   R[A] := (lua_Number)sBx             */
OP_LOADK,/* A Bx    R[A] := K[Bx]                   */
OP_LOADKX,/*    A   R[A] := K[extra arg]                */
OP_LOADFALSE,/* A   R[A] := false                   */
OP_LFALSESKIP,/*A   R[A] := false; pc++             */
OP_LOADTRUE,/*  A   R[A] := true                    */
OP_LOADNIL,/*   A B R[A], R[A+1], ..., R[A+B] := nil        */
OP_GETUPVAL,/*  A B R[A] := UpValue[B]              */
OP_SETUPVAL,/*  A B UpValue[B] := R[A]              */
 
OP_GETTABUP,/*  A B C   R[A] := UpValue[B][K[C]:string]         */
OP_GETTABLE,/*  A B C   R[A] := R[B][R[C]]              */
OP_GETI,/*  A B C   R[A] := R[B][C]                 */
OP_GETFIELD,/*  A B C   R[A] := R[B][K[C]:string]           */
 
OP_SETTABUP,/*  A B C   UpValue[A][K[B]:string] := RK(C)        */
OP_SETTABLE,/*  A B C   R[A][R[B]] := RK(C)             */
OP_SETI,/*  A B C   R[A][B] := RK(C)                */
OP_SETFIELD,/*  A B C   R[A][K[B]:string] := RK(C)          */
 
OP_NEWTABLE,/*  A B C k R[A] := {}                  */
 
OP_SELF,/*  A B C   R[A+1] := R[B]; R[A] := R[B][RK(C):string]  */
 
OP_ADDI,/*  A B sC  R[A] := R[B] + sC               */
 
OP_ADDK,/*  A B C   R[A] := R[B] + K[C]             */
OP_SUBK,/*  A B C   R[A] := R[B] - K[C]             */
OP_MULK,/*  A B C   R[A] := R[B] * K[C]             */
OP_MODK,/*  A B C   R[A] := R[B] % K[C]             */
OP_POWK,/*  A B C   R[A] := R[B] ^ K[C]             */
OP_DIVK,/*  A B C   R[A] := R[B] / K[C]             */
OP_IDIVK,/* A B C   R[A] := R[B] // K[C]                */
 
OP_BANDK,/* A B C   R[A] := R[B] & K[C]:integer         */
OP_BORK,/*  A B C   R[A] := R[B] | K[C]:integer         */
OP_BXORK,/* A B C   R[A] := R[B] ~ K[C]:integer         */
 
OP_SHRI,/*  A B sC  R[A] := R[B] >> sC              */
OP_SHLI,/*  A B sC  R[A] := sC << R[B]              */
 
OP_ADD,/*   A B C   R[A] := R[B] + R[C]             */
OP_SUB,/*   A B C   R[A] := R[B] - R[C]             */
OP_MUL,/*   A B C   R[A] := R[B] * R[C]             */
OP_MOD,/*   A B C   R[A] := R[B] % R[C]             */
OP_POW,/*   A B C   R[A] := R[B] ^ R[C]             */
OP_DIV,/*   A B C   R[A] := R[B] / R[C]             */
OP_IDIV,/*  A B C   R[A] := R[B] // R[C]                */
 
OP_BAND,/*  A B C   R[A] := R[B] & R[C]             */
OP_BOR,/*   A B C   R[A] := R[B] | R[C]             */
OP_BXOR,/*  A B C   R[A] := R[B] ~ R[C]             */
OP_SHL,/*   A B C   R[A] := R[B] << R[C]                */
OP_SHR,/*   A B C   R[A] := R[B] >> R[C]                */
 
OP_MMBIN,/* A B C   call C metamethod over R[A] and R[B]        */
OP_MMBINI,/*    A sB C k    call C metamethod over R[A] and sB  */
OP_MMBINK,/*    A B C k     call C metamethod over R[A] and K[B]    */
 
OP_UNM,/*   A B R[A] := -R[B]                   */
OP_BNOT,/*  A B R[A] := ~R[B]                   */
OP_NOT,/*   A B R[A] := not R[B]                */
OP_LEN,/*   A B R[A] := #R[B] (length operator)         */
 
OP_CONCAT,/*    A B R[A] := R[A].. ... ..R[A + B - 1]       */
 
OP_CLOSE,/* A   close all upvalues >= R[A]          */
OP_TBC,/*   A   mark variable A "to be closed"          */
OP_JMP,/*   sJ  pc += sJ                    */
OP_EQ,/*    A B k   if ((R[A] == R[B]) ~= k) then pc++      */
OP_LT,/*    A B k   if ((R[A] <  R[B]) ~= k) then pc++      */
OP_LE,/*    A B k   if ((R[A] <= R[B]) ~= k) then pc++      */
 
OP_EQK,/*   A B k   if ((R[A] == K[B]) ~= k) then pc++      */
OP_EQI,/*   A sB k  if ((R[A] == sB) ~= k) then pc++        */
OP_LTI,/*   A sB k  if ((R[A] < sB) ~= k) then pc++         */
OP_LEI,/*   A sB k  if ((R[A] <= sB) ~= k) then pc++        */
OP_GTI,/*   A sB k  if ((R[A] > sB) ~= k) then pc++         */
OP_GEI,/*   A sB k  if ((R[A] >= sB) ~= k) then pc++        */
 
OP_TEST,/*  A k if (not R[A] == k) then pc++            */
OP_TESTSET,/*   A B k   if (not R[B] == k) then pc++ else R[A] := R[B]  */
 
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 k return R[A](R[A+1], ... ,R[A+B-1])      */
 
OP_RETURN,/*    A B C k return R[A], ... ,R[A+B-2]  (see note)  */
OP_RETURN0,/*       return                      */
OP_RETURN1,/*   A   return R[A]                 */
 
OP_FORLOOP,/*   A Bx    update counters; if loop continues then pc-=Bx; */
OP_FORPREP,/*   A Bx    <check values and prepare counters>;
                        if not to run then pc+=Bx+1;            */
 
OP_TFORPREP,/*  A Bx    create upvalue for R[A + 3]; pc+=Bx     */
OP_TFORCALL,/*  A C R[A+4], ... ,R[A+3+C] := R[A](R[A+1], R[A+2]);  */
OP_TFORLOOP,/*  A Bx    if R[A+2] ~= nil then { R[A]=R[A+2]; pc -= Bx } */
 
OP_SETLIST,/*   A B C k R[A][C+i] := R[A+i], 1 <= i <= B        */
 
OP_CLOSURE,/*   A Bx    R[A] := closure(KPROTO[Bx])         */
 
OP_VARARG,/*    A C R[A], R[A+1], ..., R[A+C-2] = vararg        */
 
OP_VARARGPREP,/*A   (adjust vararg parameters)          */
 
OP_EXTRAARG/*   Ax  extra (larger) argument for previous opcode */
} OpCode;
 
 
#define NUM_OPCODES ((int)(OP_EXTRAARG) + 1)
 
 
 
/*===========================================================================
  Notes:
  (*) In OP_CALL, if (B == 0) then B = top - A. If (C == 0), then
  'top' is set to last_result+1, so next open instruction (OP_CALL,
  OP_RETURN*, OP_SETLIST) may use 'top'.
 
  (*) In OP_VARARG, if (C == 0) then use actual number of varargs and
  set top (like in OP_CALL with C == 0).
 
  (*) In OP_RETURN, if (B == 0) then return up to 'top'.
 
  (*) In OP_LOADKX and OP_NEWTABLE, the next instruction is always
  OP_EXTRAARG.
 
  (*) In OP_SETLIST, if (B == 0) then real B = 'top'; if k, then
  real C = EXTRAARG _ C (the bits of EXTRAARG concatenated with the
  bits of C).
 
  (*) In OP_NEWTABLE, B is log2 of the hash size (which is always a
  power of 2) plus 1, or zero for size zero. If not k, the array size
  is C. Otherwise, the array size is EXTRAARG _ C.
 
  (*) For comparisons, k specifies what condition the test should accept
  (true or false).
 
  (*) In OP_MMBINI/OP_MMBINK, k means the arguments were flipped
   (the constant is the first operand).
 
  (*) All 'skips' (pc++) assume that next instruction is a jump.
 
  (*) In instructions OP_RETURN/OP_TAILCALL, 'k' specifies that the
  function builds upvalues, which may need to be closed. C > 0 means
  the function is vararg, so that its 'func' must be corrected before
  returning; in this case, (C - 1) is its number of fixed parameters.
 
  (*) In comparisons with an immediate operand, C signals whether the
  original operand was a float. (It must be corrected in case of
  metamethods.)
 
===========================================================================*/
 
 
/*
** masks for instruction properties. The format is:
** bits 0-2: op mode
** bit 3: instruction set register A
** bit 4: operator is a test (next instruction must be a jump)
** bit 5: instruction uses 'L->top' set by previous instruction (when B == 0)
** bit 6: instruction sets 'L->top' for next instruction (when C == 0)
** bit 7: instruction is an MM instruction (call a metamethod)
*/
 
LUAI_DDEC(const lu_byte luaP_opmodes[NUM_OPCODES];)
 
#define getOpMode(m)    (cast(enum OpMode, luaP_opmodes[m] & 7))
#define testAMode(m)    (luaP_opmodes[m] & (1 << 3))
#define testTMode(m)    (luaP_opmodes[m] & (1 << 4))
#define testITMode(m)   (luaP_opmodes[m] & (1 << 5))
#define testOTMode(m)   (luaP_opmodes[m] & (1 << 6))
#define testMMMode(m)   (luaP_opmodes[m] & (1 << 7))
 
/* "out top" (set top for next instruction) */
#define isOT(i)  \
    ((testOTMode(GET_OPCODE(i)) && GETARG_C(i) == 0) || \
          GET_OPCODE(i) == OP_TAILCALL)
 
/* "in top" (uses top from previous instruction) */
#define isIT(i)     (testITMode(GET_OPCODE(i)) && GETARG_B(i) == 0)
 
#define opmode(mm,ot,it,t,a,m)  \
    (((mm) << 7) | ((ot) << 6) | ((it) << 5) | ((t) << 4) | ((a) << 3) | (m))
 
 
/* number of list items to accumulate before a SETLIST instruction */
#define LFIELDS_PER_FLUSH   50
 
#endif