xref: /freebsd/sys/contrib/openzfs/module/lua/lopcodes.h (revision 3c134670993bf525fcd6c4dfef84a3dfc3d4ed1b)
1 /* BEGIN CSTYLED */
2 /*
3 ** $Id: lopcodes.h,v 1.142.1.2 2014/10/20 18:32:09 roberto Exp $
4 ** Opcodes for Lua virtual machine
5 ** See Copyright Notice in lua.h
6 */
7 
8 #ifndef lopcodes_h
9 #define lopcodes_h
10 
11 #include "llimits.h"
12 
13 
14 /*===========================================================================
15   We assume that instructions are unsigned numbers.
16   All instructions have an opcode in the first 6 bits.
17   Instructions can have the following fields:
18 	`A' : 8 bits
19 	`B' : 9 bits
20 	`C' : 9 bits
21 	'Ax' : 26 bits ('A', 'B', and 'C' together)
22 	`Bx' : 18 bits (`B' and `C' together)
23 	`sBx' : signed Bx
24 
25   A signed argument is represented in excess K; that is, the number
26   value is the unsigned value minus K. K is exactly the maximum value
27   for that argument (so that -max is represented by 0, and +max is
28   represented by 2*max), which is half the maximum for the corresponding
29   unsigned argument.
30 ===========================================================================*/
31 
32 
33 enum OpMode {iABC, iABx, iAsBx, iAx};  /* basic instruction format */
34 
35 
36 /*
37 ** size and position of opcode arguments.
38 */
39 #define SIZE_C		9
40 #define SIZE_B		9
41 #define SIZE_Bx		(SIZE_C + SIZE_B)
42 #define SIZE_A		8
43 #define SIZE_Ax		(SIZE_C + SIZE_B + SIZE_A)
44 
45 #define SIZE_OP		6
46 
47 #define POS_OP		0
48 #define POS_A		(POS_OP + SIZE_OP)
49 #define POS_C		(POS_A + SIZE_A)
50 #define POS_B		(POS_C + SIZE_C)
51 #define POS_Bx		POS_C
52 #define POS_Ax		POS_A
53 
54 
55 /*
56 ** limits for opcode arguments.
57 ** we use (signed) int to manipulate most arguments,
58 ** so they must fit in LUAI_BITSINT-1 bits (-1 for sign)
59 */
60 #if SIZE_Bx < LUAI_BITSINT-1
61 #define MAXARG_Bx        ((1<<SIZE_Bx)-1)
62 #define MAXARG_sBx        (MAXARG_Bx>>1)         /* `sBx' is signed */
63 #else
64 #define MAXARG_Bx        MAX_INT
65 #define MAXARG_sBx        MAX_INT
66 #endif
67 
68 #if SIZE_Ax < LUAI_BITSINT-1
69 #define MAXARG_Ax	((1<<SIZE_Ax)-1)
70 #else
71 #define MAXARG_Ax	MAX_INT
72 #endif
73 
74 
75 #define MAXARG_A        ((1<<SIZE_A)-1)
76 #define MAXARG_B        ((1<<SIZE_B)-1)
77 #define MAXARG_C        ((1<<SIZE_C)-1)
78 
79 
80 /* creates a mask with `n' 1 bits at position `p' */
81 #define MASK1(n,p)	((~((~(Instruction)0)<<(n)))<<(p))
82 
83 /* creates a mask with `n' 0 bits at position `p' */
84 #define MASK0(n,p)	(~MASK1(n,p))
85 
86 /*
87 ** the following macros help to manipulate instructions
88 */
89 
90 #define GET_OPCODE(i)	(cast(OpCode, ((i)>>POS_OP) & MASK1(SIZE_OP,0)))
91 #define SET_OPCODE(i,o)	((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \
92 		((cast(Instruction, o)<<POS_OP)&MASK1(SIZE_OP,POS_OP))))
93 
94 #define getarg(i,pos,size)	(cast(int, ((i)>>pos) & MASK1(size,0)))
95 #define setarg(i,v,pos,size)	((i) = (((i)&MASK0(size,pos)) | \
96                 ((cast(Instruction, v)<<pos)&MASK1(size,pos))))
97 
98 #define GETARG_A(i)	getarg(i, POS_A, SIZE_A)
99 #define SETARG_A(i,v)	setarg(i, v, POS_A, SIZE_A)
100 
101 #define GETARG_B(i)	getarg(i, POS_B, SIZE_B)
102 #define SETARG_B(i,v)	setarg(i, v, POS_B, SIZE_B)
103 
104 #define GETARG_C(i)	getarg(i, POS_C, SIZE_C)
105 #define SETARG_C(i,v)	setarg(i, v, POS_C, SIZE_C)
106 
107 #define GETARG_Bx(i)	getarg(i, POS_Bx, SIZE_Bx)
108 #define SETARG_Bx(i,v)	setarg(i, v, POS_Bx, SIZE_Bx)
109 
110 #define GETARG_Ax(i)	getarg(i, POS_Ax, SIZE_Ax)
111 #define SETARG_Ax(i,v)	setarg(i, v, POS_Ax, SIZE_Ax)
112 
113 #define GETARG_sBx(i)	(GETARG_Bx(i)-MAXARG_sBx)
114 #define SETARG_sBx(i,b)	SETARG_Bx((i),cast(unsigned int, (b)+MAXARG_sBx))
115 
116 
117 #define CREATE_ABC(o,a,b,c)	((cast(Instruction, o)<<POS_OP) \
118 			| (cast(Instruction, a)<<POS_A) \
119 			| (cast(Instruction, b)<<POS_B) \
120 			| (cast(Instruction, c)<<POS_C))
121 
122 #define CREATE_ABx(o,a,bc)	((cast(Instruction, o)<<POS_OP) \
123 			| (cast(Instruction, a)<<POS_A) \
124 			| (cast(Instruction, bc)<<POS_Bx))
125 
126 #define CREATE_Ax(o,a)		((cast(Instruction, o)<<POS_OP) \
127 			| (cast(Instruction, a)<<POS_Ax))
128 
129 
130 /*
131 ** Macros to operate RK indices
132 */
133 
134 /* this bit 1 means constant (0 means register) */
135 #define BITRK		(1 << (SIZE_B - 1))
136 
137 /* test whether value is a constant */
138 #define ISK(x)		((x) & BITRK)
139 
140 /* gets the index of the constant */
141 #define INDEXK(r)	((int)(r) & ~BITRK)
142 
143 #define MAXINDEXRK	(BITRK - 1)
144 
145 /* code a constant index as a RK value */
146 #define RKASK(x)	((x) | BITRK)
147 
148 
149 /*
150 ** invalid register that fits in 8 bits
151 */
152 #define NO_REG		MAXARG_A
153 
154 
155 /*
156 ** R(x) - register
157 ** Kst(x) - constant (in constant table)
158 ** RK(x) == if ISK(x) then Kst(INDEXK(x)) else R(x)
159 */
160 
161 
162 /*
163 ** grep "ORDER OP" if you change these enums
164 */
165 
166 typedef enum {
167 /*----------------------------------------------------------------------
168 name		args	description
169 ------------------------------------------------------------------------*/
170 OP_MOVE,/*	A B	R(A) := R(B)					*/
171 OP_LOADK,/*	A Bx	R(A) := Kst(Bx)					*/
172 OP_LOADKX,/*	A 	R(A) := Kst(extra arg)				*/
173 OP_LOADBOOL,/*	A B C	R(A) := (Bool)B; if (C) pc++			*/
174 OP_LOADNIL,/*	A B	R(A), R(A+1), ..., R(A+B) := nil		*/
175 OP_GETUPVAL,/*	A B	R(A) := UpValue[B]				*/
176 
177 OP_GETTABUP,/*	A B C	R(A) := UpValue[B][RK(C)]			*/
178 OP_GETTABLE,/*	A B C	R(A) := R(B)[RK(C)]				*/
179 
180 OP_SETTABUP,/*	A B C	UpValue[A][RK(B)] := RK(C)			*/
181 OP_SETUPVAL,/*	A B	UpValue[B] := R(A)				*/
182 OP_SETTABLE,/*	A B C	R(A)[RK(B)] := RK(C)				*/
183 
184 OP_NEWTABLE,/*	A B C	R(A) := {} (size = B,C)				*/
185 
186 OP_SELF,/*	A B C	R(A+1) := R(B); R(A) := R(B)[RK(C)]		*/
187 
188 OP_ADD,/*	A B C	R(A) := RK(B) + RK(C)				*/
189 OP_SUB,/*	A B C	R(A) := RK(B) - RK(C)				*/
190 OP_MUL,/*	A B C	R(A) := RK(B) * RK(C)				*/
191 OP_DIV,/*	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_UNM,/*	A B	R(A) := -R(B)					*/
195 OP_NOT,/*	A B	R(A) := not R(B)				*/
196 OP_LEN,/*	A B	R(A) := length of R(B)				*/
197 
198 OP_CONCAT,/*	A B C	R(A) := R(B).. ... ..R(C)			*/
199 
200 OP_JMP,/*	A sBx	pc+=sBx; if (A) close all upvalues >= R(A - 1)	*/
201 OP_EQ,/*	A B C	if ((RK(B) == RK(C)) ~= A) then pc++		*/
202 OP_LT,/*	A B C	if ((RK(B) <  RK(C)) ~= A) then pc++		*/
203 OP_LE,/*	A B C	if ((RK(B) <= RK(C)) ~= A) then pc++		*/
204 
205 OP_TEST,/*	A C	if not (R(A) <=> C) then pc++			*/
206 OP_TESTSET,/*	A B C	if (R(B) <=> C) then R(A) := R(B) else pc++	*/
207 
208 OP_CALL,/*	A B C	R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */
209 OP_TAILCALL,/*	A B C	return R(A)(R(A+1), ... ,R(A+B-1))		*/
210 OP_RETURN,/*	A B	return R(A), ... ,R(A+B-2)	(see note)	*/
211 
212 OP_FORLOOP,/*	A sBx	R(A)+=R(A+2);
213 			if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/
214 OP_FORPREP,/*	A sBx	R(A)-=R(A+2); pc+=sBx				*/
215 
216 OP_TFORCALL,/*	A C	R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2));	*/
217 OP_TFORLOOP,/*	A sBx	if R(A+1) ~= nil then { R(A)=R(A+1); pc += sBx }*/
218 
219 OP_SETLIST,/*	A B C	R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B	*/
220 
221 OP_CLOSURE,/*	A Bx	R(A) := closure(KPROTO[Bx])			*/
222 
223 OP_VARARG,/*	A B	R(A), R(A+1), ..., R(A+B-2) = vararg		*/
224 
225 OP_EXTRAARG/*	Ax	extra (larger) argument for previous opcode	*/
226 } OpCode;
227 
228 
229 #define NUM_OPCODES	(cast(int, OP_EXTRAARG) + 1)
230 
231 
232 
233 /*===========================================================================
234   Notes:
235   (*) In OP_CALL, if (B == 0) then B = top. If (C == 0), then `top' is
236   set to last_result+1, so next open instruction (OP_CALL, OP_RETURN,
237   OP_SETLIST) may use `top'.
238 
239   (*) In OP_VARARG, if (B == 0) then use actual number of varargs and
240   set top (like in OP_CALL with C == 0).
241 
242   (*) In OP_RETURN, if (B == 0) then return up to `top'.
243 
244   (*) In OP_SETLIST, if (B == 0) then B = `top'; if (C == 0) then next
245   'instruction' is EXTRAARG(real C).
246 
247   (*) In OP_LOADKX, the next 'instruction' is always EXTRAARG.
248 
249   (*) For comparisons, A specifies what condition the test should accept
250   (true or false).
251 
252   (*) All `skips' (pc++) assume that next instruction is a jump.
253 
254 ===========================================================================*/
255 
256 
257 /*
258 ** masks for instruction properties. The format is:
259 ** bits 0-1: op mode
260 ** bits 2-3: C arg mode
261 ** bits 4-5: B arg mode
262 ** bit 6: instruction set register A
263 ** bit 7: operator is a test (next instruction must be a jump)
264 */
265 
266 enum OpArgMask {
267   OpArgN,  /* argument is not used */
268   OpArgU,  /* argument is used */
269   OpArgR,  /* argument is a register or a jump offset */
270   OpArgK   /* argument is a constant or register/constant */
271 };
272 
273 LUAI_DDEC const lu_byte luaP_opmodes[NUM_OPCODES];
274 
275 #define getOpMode(m)	(cast(enum OpMode, luaP_opmodes[m] & 3))
276 #define getBMode(m)	(cast(enum OpArgMask, (luaP_opmodes[m] >> 4) & 3))
277 #define getCMode(m)	(cast(enum OpArgMask, (luaP_opmodes[m] >> 2) & 3))
278 #define testAMode(m)	(luaP_opmodes[m] & (1 << 6))
279 #define testTMode(m)	(luaP_opmodes[m] & (1 << 7))
280 
281 
282 LUAI_DDEC const char *const luaP_opnames[NUM_OPCODES+1];  /* opcode names */
283 
284 
285 /* number of list items to accumulate before a SETLIST instruction */
286 #define LFIELDS_PER_FLUSH	50
287 
288 
289 #endif
290 /* END CSTYLED */
291