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 269