xref: /freebsd/contrib/lua/src/lopcodes.h (revision f7c32ed617858bcd22f8d1b03199099d50125721)
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 
12 
13 /*===========================================================================
14   We assume that instructions are unsigned 32-bit integers.
15   All instructions have an opcode in the first 7 bits.
16   Instructions can have the following formats:
17 
18         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
19         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
20 iABC          C(8)     |      B(8)     |k|     A(8)      |   Op(7)     |
21 iABx                Bx(17)               |     A(8)      |   Op(7)     |
22 iAsBx              sBx (signed)(17)      |     A(8)      |   Op(7)     |
23 iAx                           Ax(25)                     |   Op(7)     |
24 isJ                           sJ(25)                     |   Op(7)     |
25 
26   A signed argument is represented in excess K: the represented value is
27   the written unsigned value minus K, where K is half the maximum for the
28   corresponding unsigned argument.
29 ===========================================================================*/
30 
31 
32 enum OpMode {iABC, iABx, iAsBx, iAx, isJ};  /* basic instruction formats */
33 
34 
35 /*
36 ** size and position of opcode arguments.
37 */
38 #define SIZE_C		8
39 #define SIZE_B		8
40 #define SIZE_Bx		(SIZE_C + SIZE_B + 1)
41 #define SIZE_A		8
42 #define SIZE_Ax		(SIZE_Bx + SIZE_A)
43 #define SIZE_sJ		(SIZE_Bx + SIZE_A)
44 
45 #define SIZE_OP		7
46 
47 #define POS_OP		0
48 
49 #define POS_A		(POS_OP + SIZE_OP)
50 #define POS_k		(POS_A + SIZE_A)
51 #define POS_B		(POS_k + 1)
52 #define POS_C		(POS_B + SIZE_B)
53 
54 #define POS_Bx		POS_k
55 
56 #define POS_Ax		POS_A
57 
58 #define POS_sJ		POS_A
59 
60 
61 /*
62 ** limits for opcode arguments.
63 ** we use (signed) 'int' to manipulate most arguments,
64 ** so they must fit in ints.
65 */
66 
67 /* Check whether type 'int' has at least 'b' bits ('b' < 32) */
68 #define L_INTHASBITS(b)		((UINT_MAX >> ((b) - 1)) >= 1)
69 
70 
71 #if L_INTHASBITS(SIZE_Bx)
72 #define MAXARG_Bx	((1<<SIZE_Bx)-1)
73 #else
74 #define MAXARG_Bx	MAX_INT
75 #endif
76 
77 #define OFFSET_sBx	(MAXARG_Bx>>1)         /* 'sBx' is signed */
78 
79 
80 #if L_INTHASBITS(SIZE_Ax)
81 #define MAXARG_Ax	((1<<SIZE_Ax)-1)
82 #else
83 #define MAXARG_Ax	MAX_INT
84 #endif
85 
86 #if L_INTHASBITS(SIZE_sJ)
87 #define MAXARG_sJ	((1 << SIZE_sJ) - 1)
88 #else
89 #define MAXARG_sJ	MAX_INT
90 #endif
91 
92 #define OFFSET_sJ	(MAXARG_sJ >> 1)
93 
94 
95 #define MAXARG_A	((1<<SIZE_A)-1)
96 #define MAXARG_B	((1<<SIZE_B)-1)
97 #define MAXARG_C	((1<<SIZE_C)-1)
98 #define OFFSET_sC	(MAXARG_C >> 1)
99 
100 #define int2sC(i)	((i) + OFFSET_sC)
101 #define sC2int(i)	((i) - OFFSET_sC)
102 
103 
104 /* creates a mask with 'n' 1 bits at position 'p' */
105 #define MASK1(n,p)	((~((~(Instruction)0)<<(n)))<<(p))
106 
107 /* creates a mask with 'n' 0 bits at position 'p' */
108 #define MASK0(n,p)	(~MASK1(n,p))
109 
110 /*
111 ** the following macros help to manipulate instructions
112 */
113 
114 #define GET_OPCODE(i)	(cast(OpCode, ((i)>>POS_OP) & MASK1(SIZE_OP,0)))
115 #define SET_OPCODE(i,o)	((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \
116 		((cast(Instruction, o)<<POS_OP)&MASK1(SIZE_OP,POS_OP))))
117 
118 #define checkopm(i,m)	(getOpMode(GET_OPCODE(i)) == m)
119 
120 
121 #define getarg(i,pos,size)	(cast_int(((i)>>(pos)) & MASK1(size,0)))
122 #define setarg(i,v,pos,size)	((i) = (((i)&MASK0(size,pos)) | \
123                 ((cast(Instruction, v)<<pos)&MASK1(size,pos))))
124 
125 #define GETARG_A(i)	getarg(i, POS_A, SIZE_A)
126 #define SETARG_A(i,v)	setarg(i, v, POS_A, SIZE_A)
127 
128 #define GETARG_B(i)	check_exp(checkopm(i, iABC), getarg(i, POS_B, SIZE_B))
129 #define GETARG_sB(i)	sC2int(GETARG_B(i))
130 #define SETARG_B(i,v)	setarg(i, v, POS_B, SIZE_B)
131 
132 #define GETARG_C(i)	check_exp(checkopm(i, iABC), getarg(i, POS_C, SIZE_C))
133 #define GETARG_sC(i)	sC2int(GETARG_C(i))
134 #define SETARG_C(i,v)	setarg(i, v, POS_C, SIZE_C)
135 
136 #define TESTARG_k(i)	check_exp(checkopm(i, iABC), (cast_int(((i) & (1u << POS_k)))))
137 #define GETARG_k(i)	check_exp(checkopm(i, iABC), getarg(i, POS_k, 1))
138 #define SETARG_k(i,v)	setarg(i, v, POS_k, 1)
139 
140 #define GETARG_Bx(i)	check_exp(checkopm(i, iABx), getarg(i, POS_Bx, SIZE_Bx))
141 #define SETARG_Bx(i,v)	setarg(i, v, POS_Bx, SIZE_Bx)
142 
143 #define GETARG_Ax(i)	check_exp(checkopm(i, iAx), getarg(i, POS_Ax, SIZE_Ax))
144 #define SETARG_Ax(i,v)	setarg(i, v, POS_Ax, SIZE_Ax)
145 
146 #define GETARG_sBx(i)  \
147 	check_exp(checkopm(i, iAsBx), getarg(i, POS_Bx, SIZE_Bx) - OFFSET_sBx)
148 #define SETARG_sBx(i,b)	SETARG_Bx((i),cast_uint((b)+OFFSET_sBx))
149 
150 #define GETARG_sJ(i)  \
151 	check_exp(checkopm(i, isJ), getarg(i, POS_sJ, SIZE_sJ) - OFFSET_sJ)
152 #define SETARG_sJ(i,j) \
153 	setarg(i, cast_uint((j)+OFFSET_sJ), POS_sJ, SIZE_sJ)
154 
155 
156 #define CREATE_ABCk(o,a,b,c,k)	((cast(Instruction, o)<<POS_OP) \
157 			| (cast(Instruction, a)<<POS_A) \
158 			| (cast(Instruction, b)<<POS_B) \
159 			| (cast(Instruction, c)<<POS_C) \
160 			| (cast(Instruction, k)<<POS_k))
161 
162 #define CREATE_ABx(o,a,bc)	((cast(Instruction, o)<<POS_OP) \
163 			| (cast(Instruction, a)<<POS_A) \
164 			| (cast(Instruction, bc)<<POS_Bx))
165 
166 #define CREATE_Ax(o,a)		((cast(Instruction, o)<<POS_OP) \
167 			| (cast(Instruction, a)<<POS_Ax))
168 
169 #define CREATE_sJ(o,j,k)	((cast(Instruction, o) << POS_OP) \
170 			| (cast(Instruction, j) << POS_sJ) \
171 			| (cast(Instruction, k) << POS_k))
172 
173 
174 #if !defined(MAXINDEXRK)  /* (for debugging only) */
175 #define MAXINDEXRK	MAXARG_B
176 #endif
177 
178 
179 /*
180 ** invalid register that fits in 8 bits
181 */
182 #define NO_REG		MAXARG_A
183 
184 
185 /*
186 ** R[x] - register
187 ** K[x] - constant (in constant table)
188 ** RK(x) == if k(i) then K[x] else R[x]
189 */
190 
191 
192 /*
193 ** grep "ORDER OP" if you change these enums
194 */
195 
196 typedef enum {
197 /*----------------------------------------------------------------------
198   name		args	description
199 ------------------------------------------------------------------------*/
200 OP_MOVE,/*	A B	R[A] := R[B]					*/
201 OP_LOADI,/*	A sBx	R[A] := sBx					*/
202 OP_LOADF,/*	A sBx	R[A] := (lua_Number)sBx				*/
203 OP_LOADK,/*	A Bx	R[A] := K[Bx]					*/
204 OP_LOADKX,/*	A	R[A] := K[extra arg]				*/
205 OP_LOADFALSE,/*	A	R[A] := false					*/
206 OP_LFALSESKIP,/*A	R[A] := false; pc++				*/
207 OP_LOADTRUE,/*	A	R[A] := true					*/
208 OP_LOADNIL,/*	A B	R[A], R[A+1], ..., R[A+B] := nil		*/
209 OP_GETUPVAL,/*	A B	R[A] := UpValue[B]				*/
210 OP_SETUPVAL,/*	A B	UpValue[B] := R[A]				*/
211 
212 OP_GETTABUP,/*	A B C	R[A] := UpValue[B][K[C]:string]			*/
213 OP_GETTABLE,/*	A B C	R[A] := R[B][R[C]]				*/
214 OP_GETI,/*	A B C	R[A] := R[B][C]					*/
215 OP_GETFIELD,/*	A B C	R[A] := R[B][K[C]:string]			*/
216 
217 OP_SETTABUP,/*	A B C	UpValue[A][K[B]:string] := RK(C)		*/
218 OP_SETTABLE,/*	A B C	R[A][R[B]] := RK(C)				*/
219 OP_SETI,/*	A B C	R[A][B] := RK(C)				*/
220 OP_SETFIELD,/*	A B C	R[A][K[B]:string] := RK(C)			*/
221 
222 OP_NEWTABLE,/*	A B C k	R[A] := {}					*/
223 
224 OP_SELF,/*	A B C	R[A+1] := R[B]; R[A] := R[B][RK(C):string]	*/
225 
226 OP_ADDI,/*	A B sC	R[A] := R[B] + sC				*/
227 
228 OP_ADDK,/*	A B C	R[A] := R[B] + K[C]				*/
229 OP_SUBK,/*	A B C	R[A] := R[B] - K[C]				*/
230 OP_MULK,/*	A B C	R[A] := R[B] * K[C]				*/
231 OP_MODK,/*	A B C	R[A] := R[B] % K[C]				*/
232 OP_POWK,/*	A B C	R[A] := R[B] ^ K[C]				*/
233 OP_DIVK,/*	A B C	R[A] := R[B] / K[C]				*/
234 OP_IDIVK,/*	A B C	R[A] := R[B] // K[C]				*/
235 
236 OP_BANDK,/*	A B C	R[A] := R[B] & K[C]:integer			*/
237 OP_BORK,/*	A B C	R[A] := R[B] | K[C]:integer			*/
238 OP_BXORK,/*	A B C	R[A] := R[B] ~ K[C]:integer			*/
239 
240 OP_SHRI,/*	A B sC	R[A] := R[B] >> sC				*/
241 OP_SHLI,/*	A B sC	R[A] := sC << R[B]				*/
242 
243 OP_ADD,/*	A B C	R[A] := R[B] + R[C]				*/
244 OP_SUB,/*	A B C	R[A] := R[B] - R[C]				*/
245 OP_MUL,/*	A B C	R[A] := R[B] * R[C]				*/
246 OP_MOD,/*	A B C	R[A] := R[B] % R[C]				*/
247 OP_POW,/*	A B C	R[A] := R[B] ^ R[C]				*/
248 OP_DIV,/*	A B C	R[A] := R[B] / R[C]				*/
249 OP_IDIV,/*	A B C	R[A] := R[B] // R[C]				*/
250 
251 OP_BAND,/*	A B C	R[A] := R[B] & R[C]				*/
252 OP_BOR,/*	A B C	R[A] := R[B] | R[C]				*/
253 OP_BXOR,/*	A B C	R[A] := R[B] ~ R[C]				*/
254 OP_SHL,/*	A B C	R[A] := R[B] << R[C]				*/
255 OP_SHR,/*	A B C	R[A] := R[B] >> R[C]				*/
256 
257 OP_MMBIN,/*	A B C	call C metamethod over R[A] and R[B]		*/
258 OP_MMBINI,/*	A sB C k	call C metamethod over R[A] and sB	*/
259 OP_MMBINK,/*	A B C k		call C metamethod over R[A] and K[B]	*/
260 
261 OP_UNM,/*	A B	R[A] := -R[B]					*/
262 OP_BNOT,/*	A B	R[A] := ~R[B]					*/
263 OP_NOT,/*	A B	R[A] := not R[B]				*/
264 OP_LEN,/*	A B	R[A] := #R[B] (length operator)			*/
265 
266 OP_CONCAT,/*	A B	R[A] := R[A].. ... ..R[A + B - 1]		*/
267 
268 OP_CLOSE,/*	A	close all upvalues >= R[A]			*/
269 OP_TBC,/*	A	mark variable A "to be closed"			*/
270 OP_JMP,/*	sJ	pc += sJ					*/
271 OP_EQ,/*	A B k	if ((R[A] == R[B]) ~= k) then pc++		*/
272 OP_LT,/*	A B k	if ((R[A] <  R[B]) ~= k) then pc++		*/
273 OP_LE,/*	A B k	if ((R[A] <= R[B]) ~= k) then pc++		*/
274 
275 OP_EQK,/*	A B k	if ((R[A] == K[B]) ~= k) then pc++		*/
276 OP_EQI,/*	A sB k	if ((R[A] == sB) ~= k) then pc++		*/
277 OP_LTI,/*	A sB k	if ((R[A] < sB) ~= k) then pc++			*/
278 OP_LEI,/*	A sB k	if ((R[A] <= sB) ~= k) then pc++		*/
279 OP_GTI,/*	A sB k	if ((R[A] > sB) ~= k) then pc++			*/
280 OP_GEI,/*	A sB k	if ((R[A] >= sB) ~= k) then pc++		*/
281 
282 OP_TEST,/*	A k	if (not R[A] == k) then pc++			*/
283 OP_TESTSET,/*	A B k	if (not R[B] == k) then pc++ else R[A] := R[B]	*/
284 
285 OP_CALL,/*	A B C	R[A], ... ,R[A+C-2] := R[A](R[A+1], ... ,R[A+B-1]) */
286 OP_TAILCALL,/*	A B C k	return R[A](R[A+1], ... ,R[A+B-1])		*/
287 
288 OP_RETURN,/*	A B C k	return R[A], ... ,R[A+B-2]	(see note)	*/
289 OP_RETURN0,/*		return						*/
290 OP_RETURN1,/*	A	return R[A]					*/
291 
292 OP_FORLOOP,/*	A Bx	update counters; if loop continues then pc-=Bx; */
293 OP_FORPREP,/*	A Bx	<check values and prepare counters>;
294                         if not to run then pc+=Bx+1;			*/
295 
296 OP_TFORPREP,/*	A Bx	create upvalue for R[A + 3]; pc+=Bx		*/
297 OP_TFORCALL,/*	A C	R[A+4], ... ,R[A+3+C] := R[A](R[A+1], R[A+2]);	*/
298 OP_TFORLOOP,/*	A Bx	if R[A+2] ~= nil then { R[A]=R[A+2]; pc -= Bx }	*/
299 
300 OP_SETLIST,/*	A B C k	R[A][C+i] := R[A+i], 1 <= i <= B		*/
301 
302 OP_CLOSURE,/*	A Bx	R[A] := closure(KPROTO[Bx])			*/
303 
304 OP_VARARG,/*	A C	R[A], R[A+1], ..., R[A+C-2] = vararg		*/
305 
306 OP_VARARGPREP,/*A	(adjust vararg parameters)			*/
307 
308 OP_EXTRAARG/*	Ax	extra (larger) argument for previous opcode	*/
309 } OpCode;
310 
311 
312 #define NUM_OPCODES	((int)(OP_EXTRAARG) + 1)
313 
314 
315 
316 /*===========================================================================
317   Notes:
318   (*) In OP_CALL, if (B == 0) then B = top - A. If (C == 0), then
319   'top' is set to last_result+1, so next open instruction (OP_CALL,
320   OP_RETURN*, OP_SETLIST) may use 'top'.
321 
322   (*) In OP_VARARG, if (C == 0) then use actual number of varargs and
323   set top (like in OP_CALL with C == 0).
324 
325   (*) In OP_RETURN, if (B == 0) then return up to 'top'.
326 
327   (*) In OP_LOADKX and OP_NEWTABLE, the next instruction is always
328   OP_EXTRAARG.
329 
330   (*) In OP_SETLIST, if (B == 0) then real B = 'top'; if k, then
331   real C = EXTRAARG _ C (the bits of EXTRAARG concatenated with the
332   bits of C).
333 
334   (*) In OP_NEWTABLE, B is log2 of the hash size (which is always a
335   power of 2) plus 1, or zero for size zero. If not k, the array size
336   is C. Otherwise, the array size is EXTRAARG _ C.
337 
338   (*) For comparisons, k specifies what condition the test should accept
339   (true or false).
340 
341   (*) In OP_MMBINI/OP_MMBINK, k means the arguments were flipped
342    (the constant is the first operand).
343 
344   (*) All 'skips' (pc++) assume that next instruction is a jump.
345 
346   (*) In instructions OP_RETURN/OP_TAILCALL, 'k' specifies that the
347   function builds upvalues, which may need to be closed. C > 0 means
348   the function is vararg, so that its 'func' must be corrected before
349   returning; in this case, (C - 1) is its number of fixed parameters.
350 
351   (*) In comparisons with an immediate operand, C signals whether the
352   original operand was a float. (It must be corrected in case of
353   metamethods.)
354 
355 ===========================================================================*/
356 
357 
358 /*
359 ** masks for instruction properties. The format is:
360 ** bits 0-2: op mode
361 ** bit 3: instruction set register A
362 ** bit 4: operator is a test (next instruction must be a jump)
363 ** bit 5: instruction uses 'L->top' set by previous instruction (when B == 0)
364 ** bit 6: instruction sets 'L->top' for next instruction (when C == 0)
365 ** bit 7: instruction is an MM instruction (call a metamethod)
366 */
367 
368 LUAI_DDEC(const lu_byte luaP_opmodes[NUM_OPCODES];)
369 
370 #define getOpMode(m)	(cast(enum OpMode, luaP_opmodes[m] & 7))
371 #define testAMode(m)	(luaP_opmodes[m] & (1 << 3))
372 #define testTMode(m)	(luaP_opmodes[m] & (1 << 4))
373 #define testITMode(m)	(luaP_opmodes[m] & (1 << 5))
374 #define testOTMode(m)	(luaP_opmodes[m] & (1 << 6))
375 #define testMMMode(m)	(luaP_opmodes[m] & (1 << 7))
376 
377 /* "out top" (set top for next instruction) */
378 #define isOT(i)  \
379 	((testOTMode(GET_OPCODE(i)) && GETARG_C(i) == 0) || \
380           GET_OPCODE(i) == OP_TAILCALL)
381 
382 /* "in top" (uses top from previous instruction) */
383 #define isIT(i)		(testITMode(GET_OPCODE(i)) && GETARG_B(i) == 0)
384 
385 #define opmode(mm,ot,it,t,a,m)  \
386     (((mm) << 7) | ((ot) << 6) | ((it) << 5) | ((t) << 4) | ((a) << 3) | (m))
387 
388 
389 /* number of list items to accumulate before a SETLIST instruction */
390 #define LFIELDS_PER_FLUSH	50
391 
392 #endif
393