module/lua/lopcodes.h

   1 /* BEGIN CSTYLED */
   2 /*
   3 ** $Id: lopcodes.h,v 1.142.1.2 2014/10/20 18:32:09 roberto Exp $
   4 ** Opcodes for Lua virtual machine
   5 ** See Copyright Notice in lua.h
   6 */
   7
   8 #ifndef lopcodes_h
   9 #define lopcodes_h
  10
  11 #include "llimits.h"
  12
  13
  14 /*===========================================================================
  15   We assume that instructions are unsigned numbers.
  16   All instructions have an opcode in the first 6 bits.
  17   Instructions can have the following fields:
  18         `A' : 8 bits
  19         `B' : 9 bits
  20         `C' : 9 bits
  21         'Ax' : 26 bits ('A', 'B', and 'C' together)
  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, iAx};  /* 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 #define SIZE_Ax         (SIZE_C + SIZE_B + SIZE_A)
  44
  45 #define SIZE_OP         6
  46
  47 #define POS_OP          0
  48 #define POS_A           (POS_OP + SIZE_OP)
  49 #define POS_C           (POS_A + SIZE_A)
  50 #define POS_B           (POS_C + SIZE_C)
  51 #define POS_Bx          POS_C
  52 #define POS_Ax          POS_A
  53
  54
  55 /*
  56 ** limits for opcode arguments.
  57 ** we use (signed) int to manipulate most arguments,
  58 ** so they must fit in LUAI_BITSINT-1 bits (-1 for sign)
  59 */
  60 #if SIZE_Bx < LUAI_BITSINT-1
  61 #define MAXARG_Bx        ((1<<SIZE_Bx)-1)
  62 #define MAXARG_sBx        (MAXARG_Bx>>1)         /* `sBx' is signed */
  63 #else
  64 #define MAXARG_Bx        MAX_INT
  65 #define MAXARG_sBx        MAX_INT
  66 #endif
  67
  68 #if SIZE_Ax < LUAI_BITSINT-1
  69 #define MAXARG_Ax       ((1<<SIZE_Ax)-1)
  70 #else
  71 #define MAXARG_Ax       MAX_INT
  72 #endif
  73
  74
  75 #define MAXARG_A        ((1<<SIZE_A)-1)
  76 #define MAXARG_B        ((1<<SIZE_B)-1)
  77 #define MAXARG_C        ((1<<SIZE_C)-1)
  78
  79
  80 /* creates a mask with `n' 1 bits at position `p' */
  81 #define MASK1(n,p)      ((~((~(Instruction)0)<<(n)))<<(p))
  82
  83 /* creates a mask with `n' 0 bits at position `p' */
  84 #define MASK0(n,p)      (~MASK1(n,p))
  85
  86 /*
  87 ** the following macros help to manipulate instructions
  88 */
  89
  90 #define GET_OPCODE(i)   (cast(OpCode, ((i)>>POS_OP) & MASK1(SIZE_OP,0)))
  91 #define SET_OPCODE(i,o) ((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \
  92                 ((cast(Instruction, o)<<POS_OP)&MASK1(SIZE_OP,POS_OP))))
  93
  94 #define getarg(i,pos,size)      (cast(int, ((i)>>pos) & MASK1(size,0)))
  95 #define setarg(i,v,pos,size)    ((i) = (((i)&MASK0(size,pos)) | \
  96                 ((cast(Instruction, v)<<pos)&MASK1(size,pos))))
  97
  98 #define GETARG_A(i)     getarg(i, POS_A, SIZE_A)
  99 #define SETARG_A(i,v)   setarg(i, v, POS_A, SIZE_A)
 100
 101 #define GETARG_B(i)     getarg(i, POS_B, SIZE_B)
 102 #define SETARG_B(i,v)   setarg(i, v, POS_B, SIZE_B)
 103
 104 #define GETARG_C(i)     getarg(i, POS_C, SIZE_C)
 105 #define SETARG_C(i,v)   setarg(i, v, POS_C, SIZE_C)
 106
 107 #define GETARG_Bx(i)    getarg(i, POS_Bx, SIZE_Bx)
 108 #define SETARG_Bx(i,v)  setarg(i, v, POS_Bx, SIZE_Bx)
 109
 110 #define GETARG_Ax(i)    getarg(i, POS_Ax, SIZE_Ax)
 111 #define SETARG_Ax(i,v)  setarg(i, v, POS_Ax, SIZE_Ax)
 112
 113 #define GETARG_sBx(i)   (GETARG_Bx(i)-MAXARG_sBx)
 114 #define SETARG_sBx(i,b) SETARG_Bx((i),cast(unsigned int, (b)+MAXARG_sBx))
 115
 116
 117 #define CREATE_ABC(o,a,b,c)     ((cast(Instruction, o)<<POS_OP) \
 118                         | (cast(Instruction, a)<<POS_A) \
 119                         | (cast(Instruction, b)<<POS_B) \
 120                         | (cast(Instruction, c)<<POS_C))
 121
 122 #define CREATE_ABx(o,a,bc)      ((cast(Instruction, o)<<POS_OP) \
 123                         | (cast(Instruction, a)<<POS_A) \
 124                         | (cast(Instruction, bc)<<POS_Bx))
 125
 126 #define CREATE_Ax(o,a)          ((cast(Instruction, o)<<POS_OP) \
 127                         | (cast(Instruction, a)<<POS_Ax))
 128
 129
 130 /*
 131 ** Macros to operate RK indices
 132 */
 133
 134 /* this bit 1 means constant (0 means register) */
 135 #define BITRK           (1 << (SIZE_B - 1))
 136
 137 /* test whether value is a constant */
 138 #define ISK(x)          ((x) & BITRK)
 139
 140 /* gets the index of the constant */
 141 #define INDEXK(r)       ((int)(r) & ~BITRK)
 142
 143 #define MAXINDEXRK      (BITRK - 1)
 144
 145 /* code a constant index as a RK value */
 146 #define RKASK(x)        ((x) | BITRK)
 147
 148
 149 /*
 150 ** invalid register that fits in 8 bits
 151 */
 152 #define NO_REG          MAXARG_A
 153
 154
 155 /*
 156 ** R(x) - register
 157 ** Kst(x) - constant (in constant table)
 158 ** RK(x) == if ISK(x) then Kst(INDEXK(x)) else R(x)
 159 */
 160
 161
 162 /*
 163 ** grep "ORDER OP" if you change these enums
 164 */
 165
 166 typedef enum {
 167 /*----------------------------------------------------------------------
 168 name            args    description
 169 ------------------------------------------------------------------------*/
 170 OP_MOVE,/*      A B     R(A) := R(B)                                    */
 171 OP_LOADK,/*     A Bx    R(A) := Kst(Bx)                                 */
 172 OP_LOADKX,/*    A       R(A) := Kst(extra arg)                          */
 173 OP_LOADBOOL,/*  A B C   R(A) := (Bool)B; if (C) pc++                    */
 174 OP_LOADNIL,/*   A B     R(A), R(A+1), ..., R(A+B) := nil                */
 175 OP_GETUPVAL,/*  A B     R(A) := UpValue[B]                              */
 176
 177 OP_GETTABUP,/*  A B C   R(A) := UpValue[B][RK(C)]                       */
 178 OP_GETTABLE,/*  A B C   R(A) := R(B)[RK(C)]                             */
 179
 180 OP_SETTABUP,/*  A B C   UpValue[A][RK(B)] := RK(C)                      */
 181 OP_SETUPVAL,/*  A B     UpValue[B] := R(A)                              */
 182 OP_SETTABLE,/*  A B C   R(A)[RK(B)] := RK(C)                            */
 183
 184 OP_NEWTABLE,/*  A B C   R(A) := {} (size = B,C)                         */
 185
 186 OP_SELF,/*      A B C   R(A+1) := R(B); R(A) := R(B)[RK(C)]             */
 187
 188 OP_ADD,/*       A B C   R(A) := RK(B) + RK(C)                           */
 189 OP_SUB,/*       A B C   R(A) := RK(B) - RK(C)                           */
 190 OP_MUL,/*       A B C   R(A) := RK(B) * RK(C)                           */
 191 OP_DIV,/*       A B C   R(A) := RK(B) / RK(C)                           */
 192 OP_MOD,/*       A B C   R(A) := RK(B) % RK(C)                           */
 193 OP_POW,/*       A B C   R(A) := RK(B) ^ RK(C)                           */
 194 OP_UNM,/*       A B     R(A) := -R(B)                                   */
 195 OP_NOT,/*       A B     R(A) := not R(B)                                */
 196 OP_LEN,/*       A B     R(A) := length of R(B)                          */
 197
 198 OP_CONCAT,/*    A B C   R(A) := R(B).. ... ..R(C)                       */
 199
 200 OP_JMP,/*       A sBx   pc+=sBx; if (A) close all upvalues >= R(A - 1)  */
 201 OP_EQ,/*        A B C   if ((RK(B) == RK(C)) ~= A) then pc++            */
 202 OP_LT,/*        A B C   if ((RK(B) <  RK(C)) ~= A) then pc++            */
 203 OP_LE,/*        A B C   if ((RK(B) <= RK(C)) ~= A) then pc++            */
 204
 205 OP_TEST,/*      A C     if not (R(A) <=> C) then pc++                   */
 206 OP_TESTSET,/*   A B C   if (R(B) <=> C) then R(A) := R(B) else pc++     */
 207
 208 OP_CALL,/*      A B C   R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */
 209 OP_TAILCALL,/*  A B C   return R(A)(R(A+1), ... ,R(A+B-1))              */
 210 OP_RETURN,/*    A B     return R(A), ... ,R(A+B-2)      (see note)      */
 211
 212 OP_FORLOOP,/*   A sBx   R(A)+=R(A+2);
 213                         if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/
 214 OP_FORPREP,/*   A sBx   R(A)-=R(A+2); pc+=sBx                           */
 215
 216 OP_TFORCALL,/*  A C     R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2));  */
 217 OP_TFORLOOP,/*  A sBx   if R(A+1) ~= nil then { R(A)=R(A+1); pc += sBx }*/
 218
 219 OP_SETLIST,/*   A B C   R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B        */
 220
 221 OP_CLOSURE,/*   A Bx    R(A) := closure(KPROTO[Bx])                     */
 222
 223 OP_VARARG,/*    A B     R(A), R(A+1), ..., R(A+B-2) = vararg            */
 224
 225 OP_EXTRAARG/*   Ax      extra (larger) argument for previous opcode     */
 226 } OpCode;
 227
 228
 229 #define NUM_OPCODES     (cast(int, OP_EXTRAARG) + 1)
 230
 231
 232
 233 /*===========================================================================
 234   Notes:
 235   (*) In OP_CALL, if (B == 0) then B = top. If (C == 0), then `top' is
 236   set to last_result+1, so next open instruction (OP_CALL, OP_RETURN,
 237   OP_SETLIST) may use `top'.
 238
 239   (*) In OP_VARARG, if (B == 0) then use actual number of varargs and
 240   set top (like in OP_CALL with C == 0).
 241
 242   (*) In OP_RETURN, if (B == 0) then return up to `top'.
 243
 244   (*) In OP_SETLIST, if (B == 0) then B = `top'; if (C == 0) then next
 245   'instruction' is EXTRAARG(real C).
 246
 247   (*) In OP_LOADKX, the next 'instruction' is always EXTRAARG.
 248
 249   (*) For comparisons, A specifies what condition the test should accept
 250   (true or false).
 251
 252   (*) All `skips' (pc++) assume that next instruction is a jump.
 253
 254 ===========================================================================*/
 255
 256
 257 /*
 258 ** masks for instruction properties. The format is:
 259 ** bits 0-1: op mode
 260 ** bits 2-3: C arg mode
 261 ** bits 4-5: B arg mode
 262 ** bit 6: instruction set register A
 263 ** bit 7: operator is a test (next instruction must be a jump)
 264 */
 265
 266 enum OpArgMask {
 267   OpArgN,  /* argument is not used */
 268   OpArgU,  /* argument is used */
 269   OpArgR,  /* argument is a register or a jump offset */
 270   OpArgK   /* argument is a constant or register/constant */
 271 };
 272
 273 LUAI_DDEC const lu_byte luaP_opmodes[NUM_OPCODES];
 274
 275 #define getOpMode(m)    (cast(enum OpMode, luaP_opmodes[m] & 3))
 276 #define getBMode(m)     (cast(enum OpArgMask, (luaP_opmodes[m] >> 4) & 3))
 277 #define getCMode(m)     (cast(enum OpArgMask, (luaP_opmodes[m] >> 2) & 3))
 278 #define testAMode(m)    (luaP_opmodes[m] & (1 << 6))
 279 #define testTMode(m)    (luaP_opmodes[m] & (1 << 7))
 280
 281
 282 LUAI_DDEC const char *const luaP_opnames[NUM_OPCODES+1];  /* opcode names */
 283
 284
 285 /* number of list items to accumulate before a SETLIST instruction */
 286 #define LFIELDS_PER_FLUSH       50
 287
 288
 289 #endif
 290 /* END CSTYLED */