1/* $NetBSD$ */ 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 33enum 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 152typedef enum { 153/*---------------------------------------------------------------------- 154name args description 155------------------------------------------------------------------------*/ 156OP_MOVE,/* A B R(A) := R(B) */ 157OP_LOADK,/* A Bx R(A) := Kst(Bx) */ 158OP_LOADBOOL,/* A B C R(A) := (Bool)B; if (C) pc++ */ 159OP_LOADNIL,/* A B R(A) := ... := R(B) := nil */ 160OP_GETUPVAL,/* A B R(A) := UpValue[B] */ 161 162OP_GETGLOBAL,/* A Bx R(A) := Gbl[Kst(Bx)] */ 163OP_GETTABLE,/* A B C R(A) := R(B)[RK(C)] */ 164 165OP_SETGLOBAL,/* A Bx Gbl[Kst(Bx)] := R(A) */ 166OP_SETUPVAL,/* A B UpValue[B] := R(A) */ 167OP_SETTABLE,/* A B C R(A)[RK(B)] := RK(C) */ 168 169OP_NEWTABLE,/* A B C R(A) := {} (size = B,C) */ 170 171OP_SELF,/* A B C R(A+1) := R(B); R(A) := R(B)[RK(C)] */ 172 173OP_ADD,/* A B C R(A) := RK(B) + RK(C) */ 174OP_SUB,/* A B C R(A) := RK(B) - RK(C) */ 175OP_MUL,/* A B C R(A) := RK(B) * RK(C) */ 176OP_DIV,/* A B C R(A) := RK(B) / RK(C) */ 177OP_MOD,/* A B C R(A) := RK(B) % RK(C) */ 178OP_POW,/* A B C R(A) := RK(B) ^ RK(C) */ 179OP_UNM,/* A B R(A) := -R(B) */ 180OP_NOT,/* A B R(A) := not R(B) */ 181OP_LEN,/* A B R(A) := length of R(B) */ 182 183OP_CONCAT,/* A B C R(A) := R(B).. ... ..R(C) */ 184 185OP_JMP,/* sBx pc+=sBx */ 186 187OP_EQ,/* A B C if ((RK(B) == RK(C)) ~= A) then pc++ */ 188OP_LT,/* A B C if ((RK(B) < RK(C)) ~= A) then pc++ */ 189OP_LE,/* A B C if ((RK(B) <= RK(C)) ~= A) then pc++ */ 190 191OP_TEST,/* A C if not (R(A) <=> C) then pc++ */ 192OP_TESTSET,/* A B C if (R(B) <=> C) then R(A) := R(B) else pc++ */ 193 194OP_CALL,/* A B C R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */ 195OP_TAILCALL,/* A B C return R(A)(R(A+1), ... ,R(A+B-1)) */ 196OP_RETURN,/* A B return R(A), ... ,R(A+B-2) (see note) */ 197 198OP_FORLOOP,/* A sBx R(A)+=R(A+2); 199 if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/ 200OP_FORPREP,/* A sBx R(A)-=R(A+2); pc+=sBx */ 201 202OP_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++ */ 204OP_SETLIST,/* A B C R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B */ 205 206OP_CLOSE,/* A close all variables in the stack up to (>=) R(A)*/ 207OP_CLOSURE,/* A Bx R(A) := closure(KPROTO[Bx], R(A), ... ,R(A+n)) */ 208 209OP_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 247enum 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 254LUAI_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 263LUAI_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