/* ** $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