1 /* $NetBSD: lopcodes.h,v 1.1.1.1 2010/10/31 11:16:58 mbalmer Exp $ */ 2 3 /* 4 ** Id: lopcodes.h,v 1.125.1.1 2007/12/27 13:02:25 roberto Exp 5 ** Opcodes for Lua virtual machine 6 ** See Copyright Notice in lua.h 7 */ 8 9 #ifndef lopcodes_h 10 #define lopcodes_h 11 12 #include "llimits.h" 13 14 15 /*=========================================================================== 16 We assume that instructions are unsigned numbers. 17 All instructions have an opcode in the first 6 bits. 18 Instructions can have the following fields: 19 `A' : 8 bits 20 `B' : 9 bits 21 `C' : 9 bits 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}; /* 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 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 52 53 /* 54 ** limits for opcode arguments. 55 ** we use (signed) int to manipulate most arguments, 56 ** so they must fit in LUAI_BITSINT-1 bits (-1 for sign) 57 */ 58 #if SIZE_Bx < LUAI_BITSINT-1 59 #define MAXARG_Bx ((1<<SIZE_Bx)-1) 60 #define MAXARG_sBx (MAXARG_Bx>>1) /* `sBx' is signed */ 61 #else 62 #define MAXARG_Bx MAX_INT 63 #define MAXARG_sBx MAX_INT 64 #endif 65 66 67 #define MAXARG_A ((1<<SIZE_A)-1) 68 #define MAXARG_B ((1<<SIZE_B)-1) 69 #define MAXARG_C ((1<<SIZE_C)-1) 70 71 72 /* creates a mask with `n' 1 bits at position `p' */ 73 #define MASK1(n,p) ((~((~(Instruction)0)<<n))<<p) 74 75 /* creates a mask with `n' 0 bits at position `p' */ 76 #define MASK0(n,p) (~MASK1(n,p)) 77 78 /* 79 ** the following macros help to manipulate instructions 80 */ 81 82 #define GET_OPCODE(i) (cast(OpCode, ((i)>>POS_OP) & MASK1(SIZE_OP,0))) 83 #define SET_OPCODE(i,o) ((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \ 84 ((cast(Instruction, o)<<POS_OP)&MASK1(SIZE_OP,POS_OP)))) 85 86 #define GETARG_A(i) (cast(int, ((i)>>POS_A) & MASK1(SIZE_A,0))) 87 #define SETARG_A(i,u) ((i) = (((i)&MASK0(SIZE_A,POS_A)) | \ 88 ((cast(Instruction, u)<<POS_A)&MASK1(SIZE_A,POS_A)))) 89 90 #define GETARG_B(i) (cast(int, ((i)>>POS_B) & MASK1(SIZE_B,0))) 91 #define SETARG_B(i,b) ((i) = (((i)&MASK0(SIZE_B,POS_B)) | \ 92 ((cast(Instruction, b)<<POS_B)&MASK1(SIZE_B,POS_B)))) 93 94 #define GETARG_C(i) (cast(int, ((i)>>POS_C) & MASK1(SIZE_C,0))) 95 #define SETARG_C(i,b) ((i) = (((i)&MASK0(SIZE_C,POS_C)) | \ 96 ((cast(Instruction, b)<<POS_C)&MASK1(SIZE_C,POS_C)))) 97 98 #define GETARG_Bx(i) (cast(int, ((i)>>POS_Bx) & MASK1(SIZE_Bx,0))) 99 #define SETARG_Bx(i,b) ((i) = (((i)&MASK0(SIZE_Bx,POS_Bx)) | \ 100 ((cast(Instruction, b)<<POS_Bx)&MASK1(SIZE_Bx,POS_Bx)))) 101 102 #define GETARG_sBx(i) (GETARG_Bx(i)-MAXARG_sBx) 103 #define SETARG_sBx(i,b) SETARG_Bx((i),cast(unsigned int, (b)+MAXARG_sBx)) 104 105 106 #define CREATE_ABC(o,a,b,c) ((cast(Instruction, o)<<POS_OP) \ 107 | (cast(Instruction, a)<<POS_A) \ 108 | (cast(Instruction, b)<<POS_B) \ 109 | (cast(Instruction, c)<<POS_C)) 110 111 #define CREATE_ABx(o,a,bc) ((cast(Instruction, o)<<POS_OP) \ 112 | (cast(Instruction, a)<<POS_A) \ 113 | (cast(Instruction, bc)<<POS_Bx)) 114 115 116 /* 117 ** Macros to operate RK indices 118 */ 119 120 /* this bit 1 means constant (0 means register) */ 121 #define BITRK (1 << (SIZE_B - 1)) 122 123 /* test whether value is a constant */ 124 #define ISK(x) ((x) & BITRK) 125 126 /* gets the index of the constant */ 127 #define INDEXK(r) ((int)(r) & ~BITRK) 128 129 #define MAXINDEXRK (BITRK - 1) 130 131 /* code a constant index as a RK value */ 132 #define RKASK(x) ((x) | BITRK) 133 134 135 /* 136 ** invalid register that fits in 8 bits 137 */ 138 #define NO_REG MAXARG_A 139 140 141 /* 142 ** R(x) - register 143 ** Kst(x) - constant (in constant table) 144 ** RK(x) == if ISK(x) then Kst(INDEXK(x)) else R(x) 145 */ 146 147 148 /* 149 ** grep "ORDER OP" if you change these enums 150 */ 151 152 typedef enum { 153 /*---------------------------------------------------------------------- 154 name args description 155 ------------------------------------------------------------------------*/ 156 OP_MOVE,/* A B R(A) := R(B) */ 157 OP_LOADK,/* A Bx R(A) := Kst(Bx) */ 158 OP_LOADBOOL,/* A B C R(A) := (Bool)B; if (C) pc++ */ 159 OP_LOADNIL,/* A B R(A) := ... := R(B) := nil */ 160 OP_GETUPVAL,/* A B R(A) := UpValue[B] */ 161 162 OP_GETGLOBAL,/* A Bx R(A) := Gbl[Kst(Bx)] */ 163 OP_GETTABLE,/* A B C R(A) := R(B)[RK(C)] */ 164 165 OP_SETGLOBAL,/* A Bx Gbl[Kst(Bx)] := R(A) */ 166 OP_SETUPVAL,/* A B UpValue[B] := R(A) */ 167 OP_SETTABLE,/* A B C R(A)[RK(B)] := RK(C) */ 168 169 OP_NEWTABLE,/* A B C R(A) := {} (size = B,C) */ 170 171 OP_SELF,/* A B C R(A+1) := R(B); R(A) := R(B)[RK(C)] */ 172 173 OP_ADD,/* A B C R(A) := RK(B) + RK(C) */ 174 OP_SUB,/* A B C R(A) := RK(B) - RK(C) */ 175 OP_MUL,/* A B C R(A) := RK(B) * RK(C) */ 176 OP_DIV,/* A B C R(A) := RK(B) / RK(C) */ 177 OP_MOD,/* A B C R(A) := RK(B) % RK(C) */ 178 OP_POW,/* A B C R(A) := RK(B) ^ RK(C) */ 179 OP_UNM,/* A B R(A) := -R(B) */ 180 OP_NOT,/* A B R(A) := not R(B) */ 181 OP_LEN,/* A B R(A) := length of R(B) */ 182 183 OP_CONCAT,/* A B C R(A) := R(B).. ... ..R(C) */ 184 185 OP_JMP,/* sBx pc+=sBx */ 186 187 OP_EQ,/* A B C if ((RK(B) == RK(C)) ~= A) then pc++ */ 188 OP_LT,/* A B C if ((RK(B) < RK(C)) ~= A) then pc++ */ 189 OP_LE,/* A B C if ((RK(B) <= RK(C)) ~= A) then pc++ */ 190 191 OP_TEST,/* A C if not (R(A) <=> C) then pc++ */ 192 OP_TESTSET,/* A B C if (R(B) <=> C) then R(A) := R(B) else pc++ */ 193 194 OP_CALL,/* A B C R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */ 195 OP_TAILCALL,/* A B C return R(A)(R(A+1), ... ,R(A+B-1)) */ 196 OP_RETURN,/* A B return R(A), ... ,R(A+B-2) (see note) */ 197 198 OP_FORLOOP,/* A sBx R(A)+=R(A+2); 199 if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/ 200 OP_FORPREP,/* A sBx R(A)-=R(A+2); pc+=sBx */ 201 202 OP_TFORLOOP,/* A C R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2)); 203 if R(A+3) ~= nil then R(A+2)=R(A+3) else pc++ */ 204 OP_SETLIST,/* A B C R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B */ 205 206 OP_CLOSE,/* A close all variables in the stack up to (>=) R(A)*/ 207 OP_CLOSURE,/* A Bx R(A) := closure(KPROTO[Bx], R(A), ... ,R(A+n)) */ 208 209 OP_VARARG/* A B R(A), R(A+1), ..., R(A+B-1) = vararg */ 210 } OpCode; 211 212 213 #define NUM_OPCODES (cast(int, OP_VARARG) + 1) 214 215 216 217 /*=========================================================================== 218 Notes: 219 (*) In OP_CALL, if (B == 0) then B = top. C is the number of returns - 1, 220 and can be 0: OP_CALL then sets `top' to last_result+1, so 221 next open instruction (OP_CALL, OP_RETURN, OP_SETLIST) may use `top'. 222 223 (*) In OP_VARARG, if (B == 0) then use actual number of varargs and 224 set top (like in OP_CALL with C == 0). 225 226 (*) In OP_RETURN, if (B == 0) then return up to `top' 227 228 (*) In OP_SETLIST, if (B == 0) then B = `top'; 229 if (C == 0) then next `instruction' is real C 230 231 (*) For comparisons, A specifies what condition the test should accept 232 (true or false). 233 234 (*) All `skips' (pc++) assume that next instruction is a jump 235 ===========================================================================*/ 236 237 238 /* 239 ** masks for instruction properties. The format is: 240 ** bits 0-1: op mode 241 ** bits 2-3: C arg mode 242 ** bits 4-5: B arg mode 243 ** bit 6: instruction set register A 244 ** bit 7: operator is a test 245 */ 246 247 enum OpArgMask { 248 OpArgN, /* argument is not used */ 249 OpArgU, /* argument is used */ 250 OpArgR, /* argument is a register or a jump offset */ 251 OpArgK /* argument is a constant or register/constant */ 252 }; 253 254 LUAI_DATA const lu_byte luaP_opmodes[NUM_OPCODES]; 255 256 #define getOpMode(m) (cast(enum OpMode, luaP_opmodes[m] & 3)) 257 #define getBMode(m) (cast(enum OpArgMask, (luaP_opmodes[m] >> 4) & 3)) 258 #define getCMode(m) (cast(enum OpArgMask, (luaP_opmodes[m] >> 2) & 3)) 259 #define testAMode(m) (luaP_opmodes[m] & (1 << 6)) 260 #define testTMode(m) (luaP_opmodes[m] & (1 << 7)) 261 262 263 LUAI_DATA const char *const luaP_opnames[NUM_OPCODES+1]; /* opcode names */ 264 265 266 /* number of list items to accumulate before a SETLIST instruction */ 267 #define LFIELDS_PER_FLUSH 50 268 269 270 #endif 271