1 /*
2 ** $Id: lopcodes.h,v 1.142.1.1 2013/04/12 18:48:47 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 #define MAXINDEXRK	(BITRK - 1)
143 
144 /* code a constant index as a RK value */
145 #define RKASK(x)	((x) | BITRK)
146 
147 
148 /*
149 ** invalid register that fits in 8 bits
150 */
151 #define NO_REG		MAXARG_A
152 
153 
154 /*
155 ** R(x) - register
156 ** Kst(x) - constant (in constant table)
157 ** RK(x) == if ISK(x) then Kst(INDEXK(x)) else R(x)
158 */
159 
160 
161 /*
162 ** grep "ORDER OP" if you change these enums
163 */
164 
165 typedef enum {
166 /*----------------------------------------------------------------------
167 name		args	description
168 ------------------------------------------------------------------------*/
169 OP_MOVE,/*	A B	R(A) := R(B)					*/
170 OP_LOADK,/*	A Bx	R(A) := Kst(Bx)					*/
171 OP_LOADKX,/*	A 	R(A) := Kst(extra arg)				*/
172 OP_LOADBOOL,/*	A B C	R(A) := (Bool)B; if (C) pc++			*/
173 OP_LOADNIL,/*	A B	R(A), R(A+1), ..., R(A+B) := nil		*/
174 OP_GETUPVAL,/*	A B	R(A) := UpValue[B]				*/
175 
176 OP_GETTABUP,/*	A B C	R(A) := UpValue[B][RK(C)]			*/
177 OP_GETTABLE,/*	A B C	R(A) := R(B)[RK(C)]				*/
178 
179 OP_SETTABUP,/*	A B C	UpValue[A][RK(B)] := RK(C)			*/
180 OP_SETUPVAL,/*	A B	UpValue[B] := R(A)				*/
181 OP_SETTABLE,/*	A B C	R(A)[RK(B)] := RK(C)				*/
182 
183 OP_NEWTABLE,/*	A B C	R(A) := {} (size = B,C)				*/
184 
185 OP_SELF,/*	A B C	R(A+1) := R(B); R(A) := R(B)[RK(C)]		*/
186 
187 OP_ADD,/*	A B C	R(A) := RK(B) + RK(C)				*/
188 OP_SUB,/*	A B C	R(A) := RK(B) - RK(C)				*/
189 OP_MUL,/*	A B C	R(A) := RK(B) * RK(C)				*/
190 OP_DIV,/*	A B C	R(A) := RK(B) / RK(C)				*/
191 OP_MOD,/*	A B C	R(A) := RK(B) % RK(C)				*/
192 OP_POW,/*	A B C	R(A) := RK(B) ^ RK(C)				*/
193 OP_UNM,/*	A B	R(A) := -R(B)					*/
194 OP_NOT,/*	A B	R(A) := not R(B)				*/
195 OP_LEN,/*	A B	R(A) := length of R(B)				*/
196 
197 OP_CONCAT,/*	A B C	R(A) := R(B).. ... ..R(C)			*/
198 
199 OP_JMP,/*	A sBx	pc+=sBx; if (A) close all upvalues >= R(A) + 1	*/
200 OP_EQ,/*	A B C	if ((RK(B) == RK(C)) ~= A) then pc++		*/
201 OP_LT,/*	A B C	if ((RK(B) <  RK(C)) ~= A) then pc++		*/
202 OP_LE,/*	A B C	if ((RK(B) <= RK(C)) ~= A) then pc++		*/
203 
204 OP_TEST,/*	A C	if not (R(A) <=> C) then pc++			*/
205 OP_TESTSET,/*	A B C	if (R(B) <=> C) then R(A) := R(B) else pc++	*/
206 
207 OP_CALL,/*	A B C	R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */
208 OP_TAILCALL,/*	A B C	return R(A)(R(A+1), ... ,R(A+B-1))		*/
209 OP_RETURN,/*	A B	return R(A), ... ,R(A+B-2)	(see note)	*/
210 
211 OP_FORLOOP,/*	A sBx	R(A)+=R(A+2);
212 			if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/
213 OP_FORPREP,/*	A sBx	R(A)-=R(A+2); pc+=sBx				*/
214 
215 OP_TFORCALL,/*	A C	R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2));	*/
216 OP_TFORLOOP,/*	A sBx	if R(A+1) ~= nil then { R(A)=R(A+1); pc += sBx }*/
217 
218 OP_SETLIST,/*	A B C	R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B	*/
219 
220 OP_CLOSURE,/*	A Bx	R(A) := closure(KPROTO[Bx])			*/
221 
222 OP_VARARG,/*	A B	R(A), R(A+1), ..., R(A+B-2) = vararg		*/
223 
224 OP_EXTRAARG/*	Ax	extra (larger) argument for previous opcode	*/
225 } OpCode;
226 
227 
228 #define NUM_OPCODES	(cast(int, OP_EXTRAARG) + 1)
229 
230 
231 
232 /*===========================================================================
233   Notes:
234   (*) In OP_CALL, if (B == 0) then B = top. If (C == 0), then `top' is
235   set to last_result+1, so next open instruction (OP_CALL, OP_RETURN,
236   OP_SETLIST) may use `top'.
237 
238   (*) In OP_VARARG, if (B == 0) then use actual number of varargs and
239   set top (like in OP_CALL with C == 0).
240 
241   (*) In OP_RETURN, if (B == 0) then return up to `top'.
242 
243   (*) In OP_SETLIST, if (B == 0) then B = `top'; if (C == 0) then next
244   'instruction' is EXTRAARG(real C).
245 
246   (*) In OP_LOADKX, the next 'instruction' is always EXTRAARG.
247 
248   (*) For comparisons, A specifies what condition the test should accept
249   (true or false).
250 
251   (*) All `skips' (pc++) assume that next instruction is a jump.
252 
253 ===========================================================================*/
254 
255 
256 /*
257 ** masks for instruction properties. The format is:
258 ** bits 0-1: op mode
259 ** bits 2-3: C arg mode
260 ** bits 4-5: B arg mode
261 ** bit 6: instruction set register A
262 ** bit 7: operator is a test (next instruction must be a jump)
263 */
264 
265 enum OpArgMask {
266   OpArgN,  /* argument is not used */
267   OpArgU,  /* argument is used */
268   OpArgR,  /* argument is a register or a jump offset */
269   OpArgK   /* argument is a constant or register/constant */
270 };
271 
272 LUAI_DDEC const lu_byte luaP_opmodes[NUM_OPCODES];
273 
274 #define getOpMode(m)	(cast(enum OpMode, luaP_opmodes[m] & 3))
275 #define getBMode(m)	(cast(enum OpArgMask, (luaP_opmodes[m] >> 4) & 3))
276 #define getCMode(m)	(cast(enum OpArgMask, (luaP_opmodes[m] >> 2) & 3))
277 #define testAMode(m)	(luaP_opmodes[m] & (1 << 6))
278 #define testTMode(m)	(luaP_opmodes[m] & (1 << 7))
279 
280 
281 LUAI_DDEC const char *const luaP_opnames[NUM_OPCODES+1];  /* opcode names */
282 
283 
284 /* number of list items to accumulate before a SETLIST instruction */
285 #define LFIELDS_PER_FLUSH	50
286 
287 
288 #endif
289