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21d3294c | 1 | /* |
2 | ** $Id: lopcodes.h,v 1.125.1.1 2007/12/27 13:02:25 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 | `Bx' : 18 bits (`B' and `C' together) | |
21 | `sBx' : signed Bx | |
22 | ||
23 | A signed argument is represented in excess K; that is, the number | |
24 | value is the unsigned value minus K. K is exactly the maximum value | |
25 | for that argument (so that -max is represented by 0, and +max is | |
26 | represented by 2*max), which is half the maximum for the corresponding | |
27 | unsigned argument. | |
28 | ===========================================================================*/ | |
29 | ||
30 | ||
31 | enum OpMode {iABC, iABx, iAsBx}; /* basic instruction format */ | |
32 | ||
33 | ||
34 | /* | |
35 | ** size and position of opcode arguments. | |
36 | */ | |
37 | #define SIZE_C 9 | |
38 | #define SIZE_B 9 | |
39 | #define SIZE_Bx (SIZE_C + SIZE_B) | |
40 | #define SIZE_A 8 | |
41 | ||
42 | #define SIZE_OP 6 | |
43 | ||
44 | #define POS_OP 0 | |
45 | #define POS_A (POS_OP + SIZE_OP) | |
46 | #define POS_C (POS_A + SIZE_A) | |
47 | #define POS_B (POS_C + SIZE_C) | |
48 | #define POS_Bx POS_C | |
49 | ||
50 | ||
51 | /* | |
52 | ** limits for opcode arguments. | |
53 | ** we use (signed) int to manipulate most arguments, | |
54 | ** so they must fit in LUAI_BITSINT-1 bits (-1 for sign) | |
55 | */ | |
56 | #if SIZE_Bx < LUAI_BITSINT-1 | |
57 | #define MAXARG_Bx ((1<<SIZE_Bx)-1) | |
58 | #define MAXARG_sBx (MAXARG_Bx>>1) /* `sBx' is signed */ | |
59 | #else | |
60 | #define MAXARG_Bx MAX_INT | |
61 | #define MAXARG_sBx MAX_INT | |
62 | #endif | |
63 | ||
64 | ||
65 | #define MAXARG_A ((1<<SIZE_A)-1) | |
66 | #define MAXARG_B ((1<<SIZE_B)-1) | |
67 | #define MAXARG_C ((1<<SIZE_C)-1) | |
68 | ||
69 | ||
70 | /* creates a mask with `n' 1 bits at position `p' */ | |
71 | #define MASK1(n,p) ((~((~(Instruction)0)<<n))<<p) | |
72 | ||
73 | /* creates a mask with `n' 0 bits at position `p' */ | |
74 | #define MASK0(n,p) (~MASK1(n,p)) | |
75 | ||
76 | /* | |
77 | ** the following macros help to manipulate instructions | |
78 | */ | |
79 | ||
80 | #define GET_OPCODE(i) (cast(OpCode, ((i)>>POS_OP) & MASK1(SIZE_OP,0))) | |
81 | #define SET_OPCODE(i,o) ((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \ | |
82 | ((cast(Instruction, o)<<POS_OP)&MASK1(SIZE_OP,POS_OP)))) | |
83 | ||
84 | #define GETARG_A(i) (cast(int, ((i)>>POS_A) & MASK1(SIZE_A,0))) | |
85 | #define SETARG_A(i,u) ((i) = (((i)&MASK0(SIZE_A,POS_A)) | \ | |
86 | ((cast(Instruction, u)<<POS_A)&MASK1(SIZE_A,POS_A)))) | |
87 | ||
88 | #define GETARG_B(i) (cast(int, ((i)>>POS_B) & MASK1(SIZE_B,0))) | |
89 | #define SETARG_B(i,b) ((i) = (((i)&MASK0(SIZE_B,POS_B)) | \ | |
90 | ((cast(Instruction, b)<<POS_B)&MASK1(SIZE_B,POS_B)))) | |
91 | ||
92 | #define GETARG_C(i) (cast(int, ((i)>>POS_C) & MASK1(SIZE_C,0))) | |
93 | #define SETARG_C(i,b) ((i) = (((i)&MASK0(SIZE_C,POS_C)) | \ | |
94 | ((cast(Instruction, b)<<POS_C)&MASK1(SIZE_C,POS_C)))) | |
95 | ||
96 | #define GETARG_Bx(i) (cast(int, ((i)>>POS_Bx) & MASK1(SIZE_Bx,0))) | |
97 | #define SETARG_Bx(i,b) ((i) = (((i)&MASK0(SIZE_Bx,POS_Bx)) | \ | |
98 | ((cast(Instruction, b)<<POS_Bx)&MASK1(SIZE_Bx,POS_Bx)))) | |
99 | ||
100 | #define GETARG_sBx(i) (GETARG_Bx(i)-MAXARG_sBx) | |
101 | #define SETARG_sBx(i,b) SETARG_Bx((i),cast(unsigned int, (b)+MAXARG_sBx)) | |
102 | ||
103 | ||
104 | #define CREATE_ABC(o,a,b,c) ((cast(Instruction, o)<<POS_OP) \ | |
105 | | (cast(Instruction, a)<<POS_A) \ | |
106 | | (cast(Instruction, b)<<POS_B) \ | |
107 | | (cast(Instruction, c)<<POS_C)) | |
108 | ||
109 | #define CREATE_ABx(o,a,bc) ((cast(Instruction, o)<<POS_OP) \ | |
110 | | (cast(Instruction, a)<<POS_A) \ | |
111 | | (cast(Instruction, bc)<<POS_Bx)) | |
112 | ||
113 | ||
114 | /* | |
115 | ** Macros to operate RK indices | |
116 | */ | |
117 | ||
118 | /* this bit 1 means constant (0 means register) */ | |
119 | #define BITRK (1 << (SIZE_B - 1)) | |
120 | ||
121 | /* test whether value is a constant */ | |
122 | #define ISK(x) ((x) & BITRK) | |
123 | ||
124 | /* gets the index of the constant */ | |
125 | #define INDEXK(r) ((int)(r) & ~BITRK) | |
126 | ||
127 | #define MAXINDEXRK (BITRK - 1) | |
128 | ||
129 | /* code a constant index as a RK value */ | |
130 | #define RKASK(x) ((x) | BITRK) | |
131 | ||
132 | ||
133 | /* | |
134 | ** invalid register that fits in 8 bits | |
135 | */ | |
136 | #define NO_REG MAXARG_A | |
137 | ||
138 | ||
139 | /* | |
140 | ** R(x) - register | |
141 | ** Kst(x) - constant (in constant table) | |
142 | ** RK(x) == if ISK(x) then Kst(INDEXK(x)) else R(x) | |
143 | */ | |
144 | ||
145 | ||
146 | /* | |
147 | ** grep "ORDER OP" if you change these enums | |
148 | */ | |
149 | ||
150 | typedef enum { | |
151 | /*---------------------------------------------------------------------- | |
152 | name args description | |
153 | ------------------------------------------------------------------------*/ | |
154 | OP_MOVE,/* A B R(A) := R(B) */ | |
155 | OP_LOADK,/* A Bx R(A) := Kst(Bx) */ | |
156 | OP_LOADBOOL,/* A B C R(A) := (Bool)B; if (C) pc++ */ | |
157 | OP_LOADNIL,/* A B R(A) := ... := R(B) := nil */ | |
158 | OP_GETUPVAL,/* A B R(A) := UpValue[B] */ | |
159 | ||
160 | OP_GETGLOBAL,/* A Bx R(A) := Gbl[Kst(Bx)] */ | |
161 | OP_GETTABLE,/* A B C R(A) := R(B)[RK(C)] */ | |
162 | ||
163 | OP_SETGLOBAL,/* A Bx Gbl[Kst(Bx)] := R(A) */ | |
164 | OP_SETUPVAL,/* A B UpValue[B] := R(A) */ | |
165 | OP_SETTABLE,/* A B C R(A)[RK(B)] := RK(C) */ | |
166 | ||
167 | OP_NEWTABLE,/* A B C R(A) := {} (size = B,C) */ | |
168 | ||
169 | OP_SELF,/* A B C R(A+1) := R(B); R(A) := R(B)[RK(C)] */ | |
170 | ||
171 | OP_ADD,/* A B C R(A) := RK(B) + RK(C) */ | |
172 | OP_SUB,/* A B C R(A) := RK(B) - RK(C) */ | |
173 | OP_MUL,/* A B C R(A) := RK(B) * RK(C) */ | |
174 | OP_DIV,/* A B C R(A) := RK(B) / RK(C) */ | |
175 | OP_MOD,/* A B C R(A) := RK(B) % RK(C) */ | |
176 | OP_POW,/* A B C R(A) := RK(B) ^ RK(C) */ | |
177 | OP_UNM,/* A B R(A) := -R(B) */ | |
178 | OP_NOT,/* A B R(A) := not R(B) */ | |
179 | OP_LEN,/* A B R(A) := length of R(B) */ | |
180 | ||
181 | OP_CONCAT,/* A B C R(A) := R(B).. ... ..R(C) */ | |
182 | ||
183 | OP_JMP,/* sBx pc+=sBx */ | |
184 | ||
185 | OP_EQ,/* A B C if ((RK(B) == RK(C)) ~= A) then pc++ */ | |
186 | OP_LT,/* A B C if ((RK(B) < RK(C)) ~= A) then pc++ */ | |
187 | OP_LE,/* A B C if ((RK(B) <= RK(C)) ~= A) then pc++ */ | |
188 | ||
189 | OP_TEST,/* A C if not (R(A) <=> C) then pc++ */ | |
190 | OP_TESTSET,/* A B C if (R(B) <=> C) then R(A) := R(B) else pc++ */ | |
191 | ||
192 | OP_CALL,/* A B C R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */ | |
193 | OP_TAILCALL,/* A B C return R(A)(R(A+1), ... ,R(A+B-1)) */ | |
194 | OP_RETURN,/* A B return R(A), ... ,R(A+B-2) (see note) */ | |
195 | ||
196 | OP_FORLOOP,/* A sBx R(A)+=R(A+2); | |
197 | if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/ | |
198 | OP_FORPREP,/* A sBx R(A)-=R(A+2); pc+=sBx */ | |
199 | ||
200 | OP_TFORLOOP,/* A C R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2)); | |
201 | if R(A+3) ~= nil then R(A+2)=R(A+3) else pc++ */ | |
202 | OP_SETLIST,/* A B C R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B */ | |
203 | ||
204 | OP_CLOSE,/* A close all variables in the stack up to (>=) R(A)*/ | |
205 | OP_CLOSURE,/* A Bx R(A) := closure(KPROTO[Bx], R(A), ... ,R(A+n)) */ | |
206 | ||
207 | OP_VARARG/* A B R(A), R(A+1), ..., R(A+B-1) = vararg */ | |
208 | } OpCode; | |
209 | ||
210 | ||
211 | #define NUM_OPCODES (cast(int, OP_VARARG) + 1) | |
212 | ||
213 | ||
214 | ||
215 | /*=========================================================================== | |
216 | Notes: | |
217 | (*) In OP_CALL, if (B == 0) then B = top. C is the number of returns - 1, | |
218 | and can be 0: OP_CALL then sets `top' to last_result+1, so | |
219 | next open instruction (OP_CALL, OP_RETURN, OP_SETLIST) may use `top'. | |
220 | ||
221 | (*) In OP_VARARG, if (B == 0) then use actual number of varargs and | |
222 | set top (like in OP_CALL with C == 0). | |
223 | ||
224 | (*) In OP_RETURN, if (B == 0) then return up to `top' | |
225 | ||
226 | (*) In OP_SETLIST, if (B == 0) then B = `top'; | |
227 | if (C == 0) then next `instruction' is real C | |
228 | ||
229 | (*) For comparisons, A specifies what condition the test should accept | |
230 | (true or false). | |
231 | ||
232 | (*) All `skips' (pc++) assume that next instruction is a jump | |
233 | ===========================================================================*/ | |
234 | ||
235 | ||
236 | /* | |
237 | ** masks for instruction properties. The format is: | |
238 | ** bits 0-1: op mode | |
239 | ** bits 2-3: C arg mode | |
240 | ** bits 4-5: B arg mode | |
241 | ** bit 6: instruction set register A | |
242 | ** bit 7: operator is a test | |
243 | */ | |
244 | ||
245 | enum OpArgMask { | |
246 | OpArgN, /* argument is not used */ | |
247 | OpArgU, /* argument is used */ | |
248 | OpArgR, /* argument is a register or a jump offset */ | |
249 | OpArgK /* argument is a constant or register/constant */ | |
250 | }; | |
251 | ||
252 | LUAI_DATA const lu_byte luaP_opmodes[NUM_OPCODES]; | |
253 | ||
254 | #define getOpMode(m) (cast(enum OpMode, luaP_opmodes[m] & 3)) | |
255 | #define getBMode(m) (cast(enum OpArgMask, (luaP_opmodes[m] >> 4) & 3)) | |
256 | #define getCMode(m) (cast(enum OpArgMask, (luaP_opmodes[m] >> 2) & 3)) | |
257 | #define testAMode(m) (luaP_opmodes[m] & (1 << 6)) | |
258 | #define testTMode(m) (luaP_opmodes[m] & (1 << 7)) | |
259 | ||
260 | ||
261 | LUAI_DATA const char *const luaP_opnames[NUM_OPCODES+1]; /* opcode names */ | |
262 | ||
263 | ||
264 | /* number of list items to accumulate before a SETLIST instruction */ | |
265 | #define LFIELDS_PER_FLUSH 50 | |
266 | ||
267 | ||
268 | #endif |