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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 */

7 #ifndef lopcodes_h

8 #define lopcodes_h

10 #include "llimits.h"

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

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 ===========================================================================*/

 enum OpMode {iABC, iABx, iAsBx};  /* basic instruction format */

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

42 #define SIZE_OP 6

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

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

65 #define MAXARG_A ((1<<SIZE_A)-1)

66 #define MAXARG_B ((1<<SIZE_B)-1)

67 #define MAXARG_C ((1<<SIZE_C)-1)

70 /* creates a mask with `n' 1 bits at position `p' */

71 #define MASK1(n,p) ((~((~(Instruction)0)<<n))<<p)

73 /* creates a mask with `n' 0 bits at position `p' */

74 #define MASK0(n,p) (~MASK1(n,p))

76 /*

77 ** the following macros help to manipulate instructions

78 */

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))))

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))))

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))))

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))))

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))))

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

 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