/*** $Id: lopcodes.h,v 1.124 2005/12/02 18:42:08 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_OP		0#define POS_A		(POS_OP + SIZE_OP)#define POS_C		(POS_A + SIZE_A)#define POS_B		(POS_C + SIZE_C)#define POS_Bx		POS_C/*** limits for opcode arguments.** we use (signed) int to manipulate most arguments,** so they must fit in LUAI_BITSINT-1 bits (-1 for sign)*/#if SIZE_Bx < LUAI_BITSINT-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)>>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 GETARG_A(i)	(cast(int, ((i)>>POS_A) & MASK1(SIZE_A,0)))#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)<<POS_OP) \			| (cast(Instruction, a)<<POS_A) \			| (cast(Instruction, b)<<POS_B) \			| (cast(Instruction, c)<<POS_C))#define CREATE_ABx(o,a,bc)	((cast(Instruction, o)<<POS_OP) \			| (cast(Instruction, a)<<POS_A) \			| (cast(Instruction, bc)<<POS_Bx))/*** Macros to operate RK indices*//* this bit 1 means constant (0 means register) */#define BITRK		(1 << (SIZE_B - 1))/* test whether value is a constant */#define ISK(x)		((x) & BITRK)/* gets the index of the constant */#define INDEXK(r)	((int)(r) & ~BITRK)#define MAXINDEXRK	(BITRK - 1)/* code a constant index as a RK value */#define RKASK(x)	((x) | BITRK)/*** invalid register that fits in 8 bits*/#define NO_REG		MAXARG_A/*** R(x) - register** Kst(x) - constant (in constant table)** RK(x) == if ISK(x) then Kst(INDEXK(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_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_MOD,/*	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_LEN,/*	A B	R(A) := length of 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 C	if not (R(A) <=> C) then pc++			*/ OP_TESTSET,/*	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; R(A+3)=R(A) }*/OP_FORPREP,/*	A sBx	R(A)-=R(A+2); pc+=sBx				*/OP_TFORLOOP,/*	A C	R(A+3), ... ,R(A+3+C) := R(A)(R(A+1), R(A+2));                         if R(A+3) ~= nil then { pc++; R(A+2)=R(A+3); }	*/ OP_SETLIST,/*	A B C	R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B	*/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))	*/OP_VARARG/*	A B	R(A), R(A+1), ..., R(A+B-1) = vararg		*/} OpCode;#define NUM_OPCODES	(cast(int, OP_VARARG) + 1)/*===========================================================================  Notes:  (*) 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'.  (*) In OP_VARARG, if (B == 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_SETLIST, if (B == 0) then B = `top';      if (C == 0) then next `instruction' is real C  (*) For comparisons, A specifies what condition the test should accept      (true or false).  (*) All `skips' (pc++) assume that next instruction is a jump===========================================================================*//*** masks for instruction properties. The format is:** bits 0-1: op mode** bits 2-3: C arg mode** bits 4-5: B arg mode** bit 6: instruction set register A** bit 7: operator is a test*/  enum OpArgMask {  OpArgN,  /* argument is not used */  OpArgU,  /* argument is used */  OpArgR,  /* argument is a register or a jump offset */  OpArgK   /* argument is a constant or register/constant */};LUAI_DATA const lu_byte luaP_opmodes[NUM_OPCODES];#define getOpMode(m)	(cast(enum OpMode, luaP_opmodes[m] & 3))#define getBMode(m)	(cast(enum OpArgMask, (luaP_opmodes[m] >> 4) & 3))#define getCMode(m)	(cast(enum OpArgMask, (luaP_opmodes[m] >> 2) & 3))#define testAMode(m)	(luaP_opmodes[m] & (1 << 6))#define testTMode(m)	(luaP_opmodes[m] & (1 << 7))LUAI_DATA const char *const luaP_opnames[NUM_OPCODES+1];  /* opcode names *//* number of list items to accumulate before a SETLIST instruction */#define LFIELDS_PER_FLUSH	50#endif