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1 /*
2 ** $Id: lopcodes.h,v 1.149.1.1 2017/04/19 17:20:42 roberto Exp $
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 numbers.
15   All instructions have an opcode in the first 6 bits.
16   Instructions can have the following fields:
17 	'A' : 8 bits
18 	'B' : 9 bits
19 	'C' : 9 bits
20 	'Ax' : 26 bits ('A', 'B', and 'C' together)
21 	'Bx' : 18 bits ('B' and 'C' together)
22 	'sBx' : signed Bx
23 
24   A signed argument is represented in excess K; that is, the number
25   value is the unsigned value minus K. K is exactly the maximum value
26   for that argument (so that -max is represented by 0, and +max is
27   represented by 2*max), which is half the maximum for the corresponding
28   unsigned argument.
29 ===========================================================================*/
30 
31 
32 enum OpMode {iABC, iABx, iAsBx, iAx};  /* basic instruction format */
33 
34 
35 /*
36 ** size and position of opcode arguments.
37 */
38 #define SIZE_C		9
39 #define SIZE_B		9
40 #define SIZE_Bx		(SIZE_C + SIZE_B)
41 #define SIZE_A		8
42 #define SIZE_Ax		(SIZE_C + SIZE_B + SIZE_A)
43 
44 #define SIZE_OP		6
45 
46 #define POS_OP		0
47 #define POS_A		(POS_OP + SIZE_OP)
48 #define POS_C		(POS_A + SIZE_A)
49 #define POS_B		(POS_C + SIZE_C)
50 #define POS_Bx		POS_C
51 #define POS_Ax		POS_A
52 
53 
54 /*
55 ** limits for opcode arguments.
56 ** we use (signed) int to manipulate most arguments,
57 ** so they must fit in LUAI_BITSINT-1 bits (-1 for sign)
58 */
59 #if SIZE_Bx < LUAI_BITSINT-1
60 #define MAXARG_Bx        ((1<<SIZE_Bx)-1)
61 #define MAXARG_sBx        (MAXARG_Bx>>1)         /* 'sBx' is signed */
62 #else
63 #define MAXARG_Bx        MAX_INT
64 #define MAXARG_sBx        MAX_INT
65 #endif
66 
67 #if SIZE_Ax < LUAI_BITSINT-1
68 #define MAXARG_Ax	((1<<SIZE_Ax)-1)
69 #else
70 #define MAXARG_Ax	MAX_INT
71 #endif
72 
73 
74 #define MAXARG_A        ((1<<SIZE_A)-1)
75 #define MAXARG_B        ((1<<SIZE_B)-1)
76 #define MAXARG_C        ((1<<SIZE_C)-1)
77 
78 
79 /* creates a mask with 'n' 1 bits at position 'p' */
80 #define MASK1(n,p)	((~((~(Instruction)0)<<(n)))<<(p))
81 
82 /* creates a mask with 'n' 0 bits at position 'p' */
83 #define MASK0(n,p)	(~MASK1(n,p))
84 
85 /*
86 ** the following macros help to manipulate instructions
87 */
88 
89 #define GET_OPCODE(i)	(cast(OpCode, ((i)>>POS_OP) & MASK1(SIZE_OP,0)))
90 #define SET_OPCODE(i,o)	((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \
91 		((cast(Instruction, o)<<POS_OP)&MASK1(SIZE_OP,POS_OP))))
92 
93 #define getarg(i,pos,size)	(cast(int, ((i)>>pos) & MASK1(size,0)))
94 #define setarg(i,v,pos,size)	((i) = (((i)&MASK0(size,pos)) | \
95                 ((cast(Instruction, v)<<pos)&MASK1(size,pos))))
96 
97 #define GETARG_A(i)	getarg(i, POS_A, SIZE_A)
98 #define SETARG_A(i,v)	setarg(i, v, POS_A, SIZE_A)
99 
100 #define GETARG_B(i)	getarg(i, POS_B, SIZE_B)
101 #define SETARG_B(i,v)	setarg(i, v, POS_B, SIZE_B)
102 
103 #define GETARG_C(i)	getarg(i, POS_C, SIZE_C)
104 #define SETARG_C(i,v)	setarg(i, v, POS_C, SIZE_C)
105 
106 #define GETARG_Bx(i)	getarg(i, POS_Bx, SIZE_Bx)
107 #define SETARG_Bx(i,v)	setarg(i, v, POS_Bx, SIZE_Bx)
108 
109 #define GETARG_Ax(i)	getarg(i, POS_Ax, SIZE_Ax)
110 #define SETARG_Ax(i,v)	setarg(i, v, POS_Ax, SIZE_Ax)
111 
112 #define GETARG_sBx(i)	(GETARG_Bx(i)-MAXARG_sBx)
113 #define SETARG_sBx(i,b)	SETARG_Bx((i),cast(unsigned int, (b)+MAXARG_sBx))
114 
115 
116 #define CREATE_ABC(o,a,b,c)	((cast(Instruction, o)<<POS_OP) \
117 			| (cast(Instruction, a)<<POS_A) \
118 			| (cast(Instruction, b)<<POS_B) \
119 			| (cast(Instruction, c)<<POS_C))
120 
121 #define CREATE_ABx(o,a,bc)	((cast(Instruction, o)<<POS_OP) \
122 			| (cast(Instruction, a)<<POS_A) \
123 			| (cast(Instruction, bc)<<POS_Bx))
124 
125 #define CREATE_Ax(o,a)		((cast(Instruction, o)<<POS_OP) \
126 			| (cast(Instruction, a)<<POS_Ax))
127 
128 
129 /*
130 ** Macros to operate RK indices
131 */
132 
133 /* this bit 1 means constant (0 means register) */
134 #define BITRK		(1 << (SIZE_B - 1))
135 
136 /* test whether value is a constant */
137 #define ISK(x)		((x) & BITRK)
138 
139 /* gets the index of the constant */
140 #define INDEXK(r)	((int)(r) & ~BITRK)
141 
142 #if !defined(MAXINDEXRK)  /* (for debugging only) */
143 #define MAXINDEXRK	(BITRK - 1)
144 #endif
145 
146 /* code a constant index as a RK value */
147 #define RKASK(x)	((x) | BITRK)
148 
149 
150 /*
151 ** invalid register that fits in 8 bits
152 */
153 #define NO_REG		MAXARG_A
154 
155 
156 /*
157 ** R(x) - register
158 ** Kst(x) - constant (in constant table)
159 ** RK(x) == if ISK(x) then Kst(INDEXK(x)) else R(x)
160 */
161 
162 
163 /*
164 ** grep "ORDER OP" if you change these enums
165 */
166 
167 typedef enum {
168 /*----------------------------------------------------------------------
169 name		args	description
170 ------------------------------------------------------------------------*/
171 OP_MOVE,/*	A B	R(A) := R(B)					*/
172 OP_LOADK,/*	A Bx	R(A) := Kst(Bx)					*/
173 OP_LOADKX,/*	A 	R(A) := Kst(extra arg)				*/
174 OP_LOADBOOL,/*	A B C	R(A) := (Bool)B; if (C) pc++			*/
175 OP_LOADNIL,/*	A B	R(A), R(A+1), ..., R(A+B) := nil		*/
176 OP_GETUPVAL,/*	A B	R(A) := UpValue[B]				*/
177 
178 OP_GETTABUP,/*	A B C	R(A) := UpValue[B][RK(C)]			*/
179 OP_GETTABLE,/*	A B C	R(A) := R(B)[RK(C)]				*/
180 
181 OP_SETTABUP,/*	A B C	UpValue[A][RK(B)] := RK(C)			*/
182 OP_SETUPVAL,/*	A B	UpValue[B] := R(A)				*/
183 OP_SETTABLE,/*	A B C	R(A)[RK(B)] := RK(C)				*/
184 
185 OP_NEWTABLE,/*	A B C	R(A) := {} (size = B,C)				*/
186 
187 OP_SELF,/*	A B C	R(A+1) := R(B); R(A) := R(B)[RK(C)]		*/
188 
189 OP_ADD,/*	A B C	R(A) := RK(B) + RK(C)				*/
190 OP_SUB,/*	A B C	R(A) := RK(B) - RK(C)				*/
191 OP_MUL,/*	A B C	R(A) := RK(B) * RK(C)				*/
192 OP_MOD,/*	A B C	R(A) := RK(B) % RK(C)				*/
193 OP_POW,/*	A B C	R(A) := RK(B) ^ RK(C)				*/
194 OP_DIV,/*	A B C	R(A) := RK(B) / RK(C)				*/
195 OP_IDIV,/*	A B C	R(A) := RK(B) // RK(C)				*/
196 OP_BAND,/*	A B C	R(A) := RK(B) & RK(C)				*/
197 OP_BOR,/*	A B C	R(A) := RK(B) | RK(C)				*/
198 OP_BXOR,/*	A B C	R(A) := RK(B) ~ RK(C)				*/
199 OP_SHL,/*	A B C	R(A) := RK(B) << RK(C)				*/
200 OP_SHR,/*	A B C	R(A) := RK(B) >> RK(C)				*/
201 OP_UNM,/*	A B	R(A) := -R(B)					*/
202 OP_BNOT,/*	A B	R(A) := ~R(B)					*/
203 OP_NOT,/*	A B	R(A) := not R(B)				*/
204 OP_LEN,/*	A B	R(A) := length of R(B)				*/
205 
206 OP_CONCAT,/*	A B C	R(A) := R(B).. ... ..R(C)			*/
207 
208 OP_JMP,/*	A sBx	pc+=sBx; if (A) close all upvalues >= R(A - 1)	*/
209 OP_EQ,/*	A B C	if ((RK(B) == RK(C)) ~= A) then pc++		*/
210 OP_LT,/*	A B C	if ((RK(B) <  RK(C)) ~= A) then pc++		*/
211 OP_LE,/*	A B C	if ((RK(B) <= RK(C)) ~= A) then pc++		*/
212 
213 OP_TEST,/*	A C	if not (R(A) <=> C) then pc++			*/
214 OP_TESTSET,/*	A B C	if (R(B) <=> C) then R(A) := R(B) else pc++	*/
215 
216 OP_CALL,/*	A B C	R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */
217 OP_TAILCALL,/*	A B C	return R(A)(R(A+1), ... ,R(A+B-1))		*/
218 OP_RETURN,/*	A B	return R(A), ... ,R(A+B-2)	(see note)	*/
219 
220 OP_FORLOOP,/*	A sBx	R(A)+=R(A+2);
221 			if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/
222 OP_FORPREP,/*	A sBx	R(A)-=R(A+2); pc+=sBx				*/
223 
224 OP_TFORCALL,/*	A C	R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2));	*/
225 OP_TFORLOOP,/*	A sBx	if R(A+1) ~= nil then { R(A)=R(A+1); pc += sBx }*/
226 
227 OP_SETLIST,/*	A B C	R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B	*/
228 
229 OP_CLOSURE,/*	A Bx	R(A) := closure(KPROTO[Bx])			*/
230 
231 OP_VARARG,/*	A B	R(A), R(A+1), ..., R(A+B-2) = vararg		*/
232 
233 OP_EXTRAARG/*	Ax	extra (larger) argument for previous opcode	*/
234 } OpCode;
235 
236 
237 #define NUM_OPCODES	(cast(int, OP_EXTRAARG) + 1)
238 
239 
240 
241 /*===========================================================================
242   Notes:
243   (*) In OP_CALL, if (B == 0) then B = top. If (C == 0), then 'top' is
244   set to last_result+1, so next open instruction (OP_CALL, OP_RETURN,
245   OP_SETLIST) may use 'top'.
246 
247   (*) In OP_VARARG, if (B == 0) then use actual number of varargs and
248   set top (like in OP_CALL with C == 0).
249 
250   (*) In OP_RETURN, if (B == 0) then return up to 'top'.
251 
252   (*) In OP_SETLIST, if (B == 0) then B = 'top'; if (C == 0) then next
253   'instruction' is EXTRAARG(real C).
254 
255   (*) In OP_LOADKX, the next 'instruction' is always EXTRAARG.
256 
257   (*) For comparisons, A specifies what condition the test should accept
258   (true or false).
259 
260   (*) All 'skips' (pc++) assume that next instruction is a jump.
261 
262 ===========================================================================*/
263 
264 
265 /*
266 ** masks for instruction properties. The format is:
267 ** bits 0-1: op mode
268 ** bits 2-3: C arg mode
269 ** bits 4-5: B arg mode
270 ** bit 6: instruction set register A
271 ** bit 7: operator is a test (next instruction must be a jump)
272 */
273 
274 enum OpArgMask {
275   OpArgN,  /* argument is not used */
276   OpArgU,  /* argument is used */
277   OpArgR,  /* argument is a register or a jump offset */
278   OpArgK   /* argument is a constant or register/constant */
279 };
280 
281 LUAI_DDEC const lu_byte luaP_opmodes[NUM_OPCODES];
282 
283 #define getOpMode(m)	(cast(enum OpMode, luaP_opmodes[m] & 3))
284 #define getBMode(m)	(cast(enum OpArgMask, (luaP_opmodes[m] >> 4) & 3))
285 #define getCMode(m)	(cast(enum OpArgMask, (luaP_opmodes[m] >> 2) & 3))
286 #define testAMode(m)	(luaP_opmodes[m] & (1 << 6))
287 #define testTMode(m)	(luaP_opmodes[m] & (1 << 7))
288 
289 
290 LUAI_DDEC const char *const luaP_opnames[NUM_OPCODES+1];  /* opcode names */
291 
292 
293 /* number of list items to accumulate before a SETLIST instruction */
294 #define LFIELDS_PER_FLUSH	50
295 
296 
297 #endif
298