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lopcodes.h (13973B)


      1 /*
      2 ** $Id: lopcodes.h $
      3 ** Opcodes for Lua virtual machine
      4 ** See Copyright Notice in lua.h
      5 */
      6 
      7 #ifndef lopcodes_h
      8 #define lopcodes_h
      9 
     10 #include "llimits.h"
     11 #include "lobject.h"
     12 
     13 
     14 /*===========================================================================
     15   We assume that instructions are unsigned 32-bit integers.
     16   All instructions have an opcode in the first 7 bits.
     17   Instructions can have the following formats:
     18 
     19         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
     20         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
     21 iABC          C(8)     |      B(8)     |k|     A(8)      |   Op(7)     |
     22 ivABC         vC(10)     |     vB(6)   |k|     A(8)      |   Op(7)     |
     23 iABx                Bx(17)               |     A(8)      |   Op(7)     |
     24 iAsBx              sBx (signed)(17)      |     A(8)      |   Op(7)     |
     25 iAx                           Ax(25)                     |   Op(7)     |
     26 isJ                           sJ (signed)(25)            |   Op(7)     |
     27 
     28   ('v' stands for "variant", 's' for "signed", 'x' for "extended".)
     29   A signed argument is represented in excess K: The represented value is
     30   the written unsigned value minus K, where K is half (rounded down) the
     31   maximum value for the corresponding unsigned argument.
     32 ===========================================================================*/
     33 
     34 
     35 /* basic instruction formats */
     36 enum OpMode {iABC, ivABC, iABx, iAsBx, iAx, isJ};
     37 
     38 
     39 /*
     40 ** size and position of opcode arguments.
     41 */
     42 #define SIZE_C		8
     43 #define SIZE_vC		10
     44 #define SIZE_B		8
     45 #define SIZE_vB		6
     46 #define SIZE_Bx		(SIZE_C + SIZE_B + 1)
     47 #define SIZE_A		8
     48 #define SIZE_Ax		(SIZE_Bx + SIZE_A)
     49 #define SIZE_sJ		(SIZE_Bx + SIZE_A)
     50 
     51 #define SIZE_OP		7
     52 
     53 #define POS_OP		0
     54 
     55 #define POS_A		(POS_OP + SIZE_OP)
     56 #define POS_k		(POS_A + SIZE_A)
     57 #define POS_B		(POS_k + 1)
     58 #define POS_vB		(POS_k + 1)
     59 #define POS_C		(POS_B + SIZE_B)
     60 #define POS_vC		(POS_vB + SIZE_vB)
     61 
     62 #define POS_Bx		POS_k
     63 
     64 #define POS_Ax		POS_A
     65 
     66 #define POS_sJ		POS_A
     67 
     68 
     69 /*
     70 ** limits for opcode arguments.
     71 ** we use (signed) 'int' to manipulate most arguments,
     72 ** so they must fit in ints.
     73 */
     74 
     75 /*
     76 ** Check whether type 'int' has at least 'b' + 1 bits.
     77 ** 'b' < 32; +1 for the sign bit.
     78 */
     79 #define L_INTHASBITS(b)		((UINT_MAX >> (b)) >= 1)
     80 
     81 
     82 #if L_INTHASBITS(SIZE_Bx)
     83 #define MAXARG_Bx	((1<<SIZE_Bx)-1)
     84 #else
     85 #define MAXARG_Bx	INT_MAX
     86 #endif
     87 
     88 #define OFFSET_sBx	(MAXARG_Bx>>1)         /* 'sBx' is signed */
     89 
     90 
     91 #if L_INTHASBITS(SIZE_Ax)
     92 #define MAXARG_Ax	((1<<SIZE_Ax)-1)
     93 #else
     94 #define MAXARG_Ax	INT_MAX
     95 #endif
     96 
     97 #if L_INTHASBITS(SIZE_sJ)
     98 #define MAXARG_sJ	((1 << SIZE_sJ) - 1)
     99 #else
    100 #define MAXARG_sJ	INT_MAX
    101 #endif
    102 
    103 #define OFFSET_sJ	(MAXARG_sJ >> 1)
    104 
    105 
    106 #define MAXARG_A	((1<<SIZE_A)-1)
    107 #define MAXARG_B	((1<<SIZE_B)-1)
    108 #define MAXARG_vB	((1<<SIZE_vB)-1)
    109 #define MAXARG_C	((1<<SIZE_C)-1)
    110 #define MAXARG_vC	((1<<SIZE_vC)-1)
    111 #define OFFSET_sC	(MAXARG_C >> 1)
    112 
    113 #define int2sC(i)	((i) + OFFSET_sC)
    114 #define sC2int(i)	((i) - OFFSET_sC)
    115 
    116 
    117 /* creates a mask with 'n' 1 bits at position 'p' */
    118 #define MASK1(n,p)	((~((~(Instruction)0)<<(n)))<<(p))
    119 
    120 /* creates a mask with 'n' 0 bits at position 'p' */
    121 #define MASK0(n,p)	(~MASK1(n,p))
    122 
    123 /*
    124 ** the following macros help to manipulate instructions
    125 */
    126 
    127 #define GET_OPCODE(i)	(cast(OpCode, ((i)>>POS_OP) & MASK1(SIZE_OP,0)))
    128 #define SET_OPCODE(i,o)	((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \
    129 		((cast(Instruction, o)<<POS_OP)&MASK1(SIZE_OP,POS_OP))))
    130 
    131 #define checkopm(i,m)	(getOpMode(GET_OPCODE(i)) == m)
    132 
    133 
    134 #define getarg(i,pos,size)	(cast_int(((i)>>(pos)) & MASK1(size,0)))
    135 #define setarg(i,v,pos,size)	((i) = (((i)&MASK0(size,pos)) | \
    136                 ((cast(Instruction, v)<<pos)&MASK1(size,pos))))
    137 
    138 #define GETARG_A(i)	getarg(i, POS_A, SIZE_A)
    139 #define SETARG_A(i,v)	setarg(i, v, POS_A, SIZE_A)
    140 
    141 #define GETARG_B(i)  \
    142 	check_exp(checkopm(i, iABC), getarg(i, POS_B, SIZE_B))
    143 #define GETARG_vB(i)  \
    144 	check_exp(checkopm(i, ivABC), getarg(i, POS_vB, SIZE_vB))
    145 #define GETARG_sB(i)	sC2int(GETARG_B(i))
    146 #define SETARG_B(i,v)	setarg(i, v, POS_B, SIZE_B)
    147 #define SETARG_vB(i,v)	setarg(i, v, POS_vB, SIZE_vB)
    148 
    149 #define GETARG_C(i)  \
    150 	check_exp(checkopm(i, iABC), getarg(i, POS_C, SIZE_C))
    151 #define GETARG_vC(i)  \
    152 	check_exp(checkopm(i, ivABC), getarg(i, POS_vC, SIZE_vC))
    153 #define GETARG_sC(i)	sC2int(GETARG_C(i))
    154 #define SETARG_C(i,v)	setarg(i, v, POS_C, SIZE_C)
    155 #define SETARG_vC(i,v)	setarg(i, v, POS_vC, SIZE_vC)
    156 
    157 #define TESTARG_k(i)	(cast_int(((i) & (1u << POS_k))))
    158 #define GETARG_k(i)	getarg(i, POS_k, 1)
    159 #define SETARG_k(i,v)	setarg(i, v, POS_k, 1)
    160 
    161 #define GETARG_Bx(i)	check_exp(checkopm(i, iABx), getarg(i, POS_Bx, SIZE_Bx))
    162 #define SETARG_Bx(i,v)	setarg(i, v, POS_Bx, SIZE_Bx)
    163 
    164 #define GETARG_Ax(i)	check_exp(checkopm(i, iAx), getarg(i, POS_Ax, SIZE_Ax))
    165 #define SETARG_Ax(i,v)	setarg(i, v, POS_Ax, SIZE_Ax)
    166 
    167 #define GETARG_sBx(i)  \
    168 	check_exp(checkopm(i, iAsBx), getarg(i, POS_Bx, SIZE_Bx) - OFFSET_sBx)
    169 #define SETARG_sBx(i,b)	SETARG_Bx((i),cast_uint((b)+OFFSET_sBx))
    170 
    171 #define GETARG_sJ(i)  \
    172 	check_exp(checkopm(i, isJ), getarg(i, POS_sJ, SIZE_sJ) - OFFSET_sJ)
    173 #define SETARG_sJ(i,j) \
    174 	setarg(i, cast_uint((j)+OFFSET_sJ), POS_sJ, SIZE_sJ)
    175 
    176 
    177 #define CREATE_ABCk(o,a,b,c,k)	((cast(Instruction, o)<<POS_OP) \
    178 			| (cast(Instruction, a)<<POS_A) \
    179 			| (cast(Instruction, b)<<POS_B) \
    180 			| (cast(Instruction, c)<<POS_C) \
    181 			| (cast(Instruction, k)<<POS_k))
    182 
    183 #define CREATE_vABCk(o,a,b,c,k)	((cast(Instruction, o)<<POS_OP) \
    184 			| (cast(Instruction, a)<<POS_A) \
    185 			| (cast(Instruction, b)<<POS_vB) \
    186 			| (cast(Instruction, c)<<POS_vC) \
    187 			| (cast(Instruction, k)<<POS_k))
    188 
    189 #define CREATE_ABx(o,a,bc)	((cast(Instruction, o)<<POS_OP) \
    190 			| (cast(Instruction, a)<<POS_A) \
    191 			| (cast(Instruction, bc)<<POS_Bx))
    192 
    193 #define CREATE_Ax(o,a)		((cast(Instruction, o)<<POS_OP) \
    194 			| (cast(Instruction, a)<<POS_Ax))
    195 
    196 #define CREATE_sJ(o,j,k)	((cast(Instruction, o) << POS_OP) \
    197 			| (cast(Instruction, j) << POS_sJ) \
    198 			| (cast(Instruction, k) << POS_k))
    199 
    200 
    201 #if !defined(MAXINDEXRK)  /* (for debugging only) */
    202 #define MAXINDEXRK	MAXARG_B
    203 #endif
    204 
    205 
    206 /*
    207 ** Maximum size for the stack of a Lua function. It must fit in 8 bits.
    208 ** The highest valid register is one less than this value.
    209 */
    210 #define MAX_FSTACK	MAXARG_A
    211 
    212 /*
    213 ** Invalid register (one more than last valid register).
    214 */
    215 #define NO_REG		MAX_FSTACK
    216 
    217 
    218 
    219 /*
    220 ** R[x] - register
    221 ** K[x] - constant (in constant table)
    222 ** RK(x) == if k(i) then K[x] else R[x]
    223 */
    224 
    225 
    226 /*
    227 ** Grep "ORDER OP" if you change these enums. Opcodes marked with a (*)
    228 ** has extra descriptions in the notes after the enumeration.
    229 */
    230 
    231 typedef enum {
    232 /*----------------------------------------------------------------------
    233   name		args	description
    234 ------------------------------------------------------------------------*/
    235 OP_MOVE,/*	A B	R[A] := R[B]					*/
    236 OP_LOADI,/*	A sBx	R[A] := sBx					*/
    237 OP_LOADF,/*	A sBx	R[A] := (lua_Number)sBx				*/
    238 OP_LOADK,/*	A Bx	R[A] := K[Bx]					*/
    239 OP_LOADKX,/*	A	R[A] := K[extra arg]				*/
    240 OP_LOADFALSE,/*	A	R[A] := false					*/
    241 OP_LFALSESKIP,/*A	R[A] := false; pc++	(*)			*/
    242 OP_LOADTRUE,/*	A	R[A] := true					*/
    243 OP_LOADNIL,/*	A B	R[A], R[A+1], ..., R[A+B] := nil		*/
    244 OP_GETUPVAL,/*	A B	R[A] := UpValue[B]				*/
    245 OP_SETUPVAL,/*	A B	UpValue[B] := R[A]				*/
    246 
    247 OP_GETTABUP,/*	A B C	R[A] := UpValue[B][K[C]:shortstring]		*/
    248 OP_GETTABLE,/*	A B C	R[A] := R[B][R[C]]				*/
    249 OP_GETI,/*	A B C	R[A] := R[B][C]					*/
    250 OP_GETFIELD,/*	A B C	R[A] := R[B][K[C]:shortstring]			*/
    251 
    252 OP_SETTABUP,/*	A B C	UpValue[A][K[B]:shortstring] := RK(C)		*/
    253 OP_SETTABLE,/*	A B C	R[A][R[B]] := RK(C)				*/
    254 OP_SETI,/*	A B C	R[A][B] := RK(C)				*/
    255 OP_SETFIELD,/*	A B C	R[A][K[B]:shortstring] := RK(C)			*/
    256 
    257 OP_NEWTABLE,/*	A B C k	R[A] := {}					*/
    258 
    259 OP_SELF,/*	A B C	R[A+1] := R[B]; R[A] := R[B][K[C]:shortstring]	*/
    260 
    261 OP_ADDI,/*	A B sC	R[A] := R[B] + sC				*/
    262 
    263 OP_ADDK,/*	A B C	R[A] := R[B] + K[C]:number			*/
    264 OP_SUBK,/*	A B C	R[A] := R[B] - K[C]:number			*/
    265 OP_MULK,/*	A B C	R[A] := R[B] * K[C]:number			*/
    266 OP_MODK,/*	A B C	R[A] := R[B] % K[C]:number			*/
    267 OP_POWK,/*	A B C	R[A] := R[B] ^ K[C]:number			*/
    268 OP_DIVK,/*	A B C	R[A] := R[B] / K[C]:number			*/
    269 OP_IDIVK,/*	A B C	R[A] := R[B] // K[C]:number			*/
    270 
    271 OP_BANDK,/*	A B C	R[A] := R[B] & K[C]:integer			*/
    272 OP_BORK,/*	A B C	R[A] := R[B] | K[C]:integer			*/
    273 OP_BXORK,/*	A B C	R[A] := R[B] ~ K[C]:integer			*/
    274 
    275 OP_SHRI,/*	A B sC	R[A] := R[B] >> sC				*/
    276 OP_SHLI,/*	A B sC	R[A] := sC << R[B]				*/
    277 
    278 OP_ADD,/*	A B C	R[A] := R[B] + R[C]				*/
    279 OP_SUB,/*	A B C	R[A] := R[B] - R[C]				*/
    280 OP_MUL,/*	A B C	R[A] := R[B] * R[C]				*/
    281 OP_MOD,/*	A B C	R[A] := R[B] % R[C]				*/
    282 OP_POW,/*	A B C	R[A] := R[B] ^ R[C]				*/
    283 OP_DIV,/*	A B C	R[A] := R[B] / R[C]				*/
    284 OP_IDIV,/*	A B C	R[A] := R[B] // R[C]				*/
    285 
    286 OP_BAND,/*	A B C	R[A] := R[B] & R[C]				*/
    287 OP_BOR,/*	A B C	R[A] := R[B] | R[C]				*/
    288 OP_BXOR,/*	A B C	R[A] := R[B] ~ R[C]				*/
    289 OP_SHL,/*	A B C	R[A] := R[B] << R[C]				*/
    290 OP_SHR,/*	A B C	R[A] := R[B] >> R[C]				*/
    291 
    292 OP_MMBIN,/*	A B C	call C metamethod over R[A] and R[B]	(*)	*/
    293 OP_MMBINI,/*	A sB C k	call C metamethod over R[A] and sB	*/
    294 OP_MMBINK,/*	A B C k		call C metamethod over R[A] and K[B]	*/
    295 
    296 OP_UNM,/*	A B	R[A] := -R[B]					*/
    297 OP_BNOT,/*	A B	R[A] := ~R[B]					*/
    298 OP_NOT,/*	A B	R[A] := not R[B]				*/
    299 OP_LEN,/*	A B	R[A] := #R[B] (length operator)			*/
    300 
    301 OP_CONCAT,/*	A B	R[A] := R[A].. ... ..R[A + B - 1]		*/
    302 
    303 OP_CLOSE,/*	A	close all upvalues >= R[A]			*/
    304 OP_TBC,/*	A	mark variable A "to be closed"			*/
    305 OP_JMP,/*	sJ	pc += sJ					*/
    306 OP_EQ,/*	A B k	if ((R[A] == R[B]) ~= k) then pc++		*/
    307 OP_LT,/*	A B k	if ((R[A] <  R[B]) ~= k) then pc++		*/
    308 OP_LE,/*	A B k	if ((R[A] <= R[B]) ~= k) then pc++		*/
    309 
    310 OP_EQK,/*	A B k	if ((R[A] == K[B]) ~= k) then pc++		*/
    311 OP_EQI,/*	A sB k	if ((R[A] == sB) ~= k) then pc++		*/
    312 OP_LTI,/*	A sB k	if ((R[A] < sB) ~= k) then pc++			*/
    313 OP_LEI,/*	A sB k	if ((R[A] <= sB) ~= k) then pc++		*/
    314 OP_GTI,/*	A sB k	if ((R[A] > sB) ~= k) then pc++			*/
    315 OP_GEI,/*	A sB k	if ((R[A] >= sB) ~= k) then pc++		*/
    316 
    317 OP_TEST,/*	A k	if (not R[A] == k) then pc++			*/
    318 OP_TESTSET,/*	A B k	if (not R[B] == k) then pc++ else R[A] := R[B] (*) */
    319 
    320 OP_CALL,/*	A B C	R[A], ... ,R[A+C-2] := R[A](R[A+1], ... ,R[A+B-1]) */
    321 OP_TAILCALL,/*	A B C k	return R[A](R[A+1], ... ,R[A+B-1])		*/
    322 
    323 OP_RETURN,/*	A B C k	return R[A], ... ,R[A+B-2]	(see note)	*/
    324 OP_RETURN0,/*		return						*/
    325 OP_RETURN1,/*	A	return R[A]					*/
    326 
    327 OP_FORLOOP,/*	A Bx	update counters; if loop continues then pc-=Bx; */
    328 OP_FORPREP,/*	A Bx	<check values and prepare counters>;
    329                         if not to run then pc+=Bx+1;			*/
    330 
    331 OP_TFORPREP,/*	A Bx	create upvalue for R[A + 3]; pc+=Bx		*/
    332 OP_TFORCALL,/*	A C	R[A+4], ... ,R[A+3+C] := R[A](R[A+1], R[A+2]);	*/
    333 OP_TFORLOOP,/*	A Bx	if R[A+2] ~= nil then { R[A]=R[A+2]; pc -= Bx }	*/
    334 
    335 OP_SETLIST,/*	A vB vC k	R[A][vC+i] := R[A+i], 1 <= i <= vB	*/
    336 
    337 OP_CLOSURE,/*	A Bx	R[A] := closure(KPROTO[Bx])			*/
    338 
    339 OP_VARARG,/*	A C	R[A], R[A+1], ..., R[A+C-2] = vararg		*/
    340 
    341 OP_VARARGPREP,/*A	(adjust vararg parameters)			*/
    342 
    343 OP_EXTRAARG/*	Ax	extra (larger) argument for previous opcode	*/
    344 } OpCode;
    345 
    346 
    347 #define NUM_OPCODES	((int)(OP_EXTRAARG) + 1)
    348 
    349 
    350 
    351 /*===========================================================================
    352   Notes:
    353 
    354   (*) Opcode OP_LFALSESKIP is used to convert a condition to a boolean
    355   value, in a code equivalent to (not cond ? false : true).  (It
    356   produces false and skips the next instruction producing true.)
    357 
    358   (*) Opcodes OP_MMBIN and variants follow each arithmetic and
    359   bitwise opcode. If the operation succeeds, it skips this next
    360   opcode. Otherwise, this opcode calls the corresponding metamethod.
    361 
    362   (*) Opcode OP_TESTSET is used in short-circuit expressions that need
    363   both to jump and to produce a value, such as (a = b or c).
    364 
    365   (*) In OP_CALL, if (B == 0) then B = top - A. If (C == 0), then
    366   'top' is set to last_result+1, so next open instruction (OP_CALL,
    367   OP_RETURN*, OP_SETLIST) may use 'top'.
    368 
    369   (*) In OP_VARARG, if (C == 0) then use actual number of varargs and
    370   set top (like in OP_CALL with C == 0).
    371 
    372   (*) In OP_RETURN, if (B == 0) then return up to 'top'.
    373 
    374   (*) In OP_LOADKX and OP_NEWTABLE, the next instruction is always
    375   OP_EXTRAARG.
    376 
    377   (*) In OP_SETLIST, if (B == 0) then real B = 'top'; if k, then
    378   real C = EXTRAARG _ C (the bits of EXTRAARG concatenated with the
    379   bits of C).
    380 
    381   (*) In OP_NEWTABLE, B is log2 of the hash size (which is always a
    382   power of 2) plus 1, or zero for size zero. If not k, the array size
    383   is C. Otherwise, the array size is EXTRAARG _ C.
    384 
    385   (*) For comparisons, k specifies what condition the test should accept
    386   (true or false).
    387 
    388   (*) In OP_MMBINI/OP_MMBINK, k means the arguments were flipped
    389    (the constant is the first operand).
    390 
    391   (*) All 'skips' (pc++) assume that next instruction is a jump.
    392 
    393   (*) In instructions OP_RETURN/OP_TAILCALL, 'k' specifies that the
    394   function builds upvalues, which may need to be closed. C > 0 means
    395   the function is vararg, so that its 'func' must be corrected before
    396   returning; in this case, (C - 1) is its number of fixed parameters.
    397 
    398   (*) In comparisons with an immediate operand, C signals whether the
    399   original operand was a float. (It must be corrected in case of
    400   metamethods.)
    401 
    402 ===========================================================================*/
    403 
    404 
    405 /*
    406 ** masks for instruction properties. The format is:
    407 ** bits 0-2: op mode
    408 ** bit 3: instruction set register A
    409 ** bit 4: operator is a test (next instruction must be a jump)
    410 ** bit 5: instruction uses 'L->top' set by previous instruction (when B == 0)
    411 ** bit 6: instruction sets 'L->top' for next instruction (when C == 0)
    412 ** bit 7: instruction is an MM instruction (call a metamethod)
    413 */
    414 
    415 LUAI_DDEC(const lu_byte luaP_opmodes[NUM_OPCODES];)
    416 
    417 #define getOpMode(m)	(cast(enum OpMode, luaP_opmodes[m] & 7))
    418 #define testAMode(m)	(luaP_opmodes[m] & (1 << 3))
    419 #define testTMode(m)	(luaP_opmodes[m] & (1 << 4))
    420 #define testITMode(m)	(luaP_opmodes[m] & (1 << 5))
    421 #define testOTMode(m)	(luaP_opmodes[m] & (1 << 6))
    422 #define testMMMode(m)	(luaP_opmodes[m] & (1 << 7))
    423 
    424 
    425 LUAI_FUNC int luaP_isOT (Instruction i);
    426 LUAI_FUNC int luaP_isIT (Instruction i);
    427 
    428 
    429 #endif