external/mit/lua/dist/src/lopcodes.h

   1 /*      $NetBSD: lopcodes.h,v 1.3 2015/02/02 14:03:05 lneto Exp $       */
   2
   3 /*
   4 ** Id: lopcodes.h,v 1.148 2014/10/25 11:50:46 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         'Ax' : 26 bits ('A', 'B', and 'C' together)
  23         'Bx' : 18 bits ('B' and 'C' together)
  24         'sBx' : signed Bx
  25
  26   A signed argument is represented in excess K; that is, the number
  27   value is the unsigned value minus K. K is exactly the maximum value
  28   for that argument (so that -max is represented by 0, and +max is
  29   represented by 2*max), which is half the maximum for the corresponding
  30   unsigned argument.
  31 ===========================================================================*/
  32
  33
  34 enum OpMode {iABC, iABx, iAsBx, iAx};  /* basic instruction format */
  35
  36
  37 /*
  38 ** size and position of opcode arguments.
  39 */
  40 #define SIZE_C          9
  41 #define SIZE_B          9
  42 #define SIZE_Bx         (SIZE_C + SIZE_B)
  43 #define SIZE_A          8
  44 #define SIZE_Ax         (SIZE_C + SIZE_B + SIZE_A)
  45
  46 #define SIZE_OP         6
  47
  48 #define POS_OP          0
  49 #define POS_A           (POS_OP + SIZE_OP)
  50 #define POS_C           (POS_A + SIZE_A)
  51 #define POS_B           (POS_C + SIZE_C)
  52 #define POS_Bx          POS_C
  53 #define POS_Ax          POS_A
  54
  55
  56 /*
  57 ** limits for opcode arguments.
  58 ** we use (signed) int to manipulate most arguments,
  59 ** so they must fit in LUAI_BITSINT-1 bits (-1 for sign)
  60 */
  61 #if SIZE_Bx < LUAI_BITSINT-1
  62 #define MAXARG_Bx        ((1<<SIZE_Bx)-1)
  63 #define MAXARG_sBx        (MAXARG_Bx>>1)         /* 'sBx' is signed */
  64 #else
  65 #define MAXARG_Bx        MAX_INT
  66 #define MAXARG_sBx        MAX_INT
  67 #endif
  68
  69 #if SIZE_Ax < LUAI_BITSINT-1
  70 #define MAXARG_Ax       ((1<<SIZE_Ax)-1)
  71 #else
  72 #define MAXARG_Ax       MAX_INT
  73 #endif
  74
  75
  76 #define MAXARG_A        ((1<<SIZE_A)-1)
  77 #define MAXARG_B        ((1<<SIZE_B)-1)
  78 #define MAXARG_C        ((1<<SIZE_C)-1)
  79
  80
  81 /* creates a mask with 'n' 1 bits at position 'p' */
  82 #define MASK1(n,p)      ((~((~(Instruction)0)<<(n)))<<(p))
  83
  84 /* creates a mask with 'n' 0 bits at position 'p' */
  85 #define MASK0(n,p)      (~MASK1(n,p))
  86
  87 /*
  88 ** the following macros help to manipulate instructions
  89 */
  90
  91 #define GET_OPCODE(i)   (cast(OpCode, ((i)>>POS_OP) & MASK1(SIZE_OP,0)))
  92 #define SET_OPCODE(i,o) ((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \
  93                 ((cast(Instruction, o)<<POS_OP)&MASK1(SIZE_OP,POS_OP))))
  94
  95 #define getarg(i,pos,size)      (cast(int, ((i)>>pos) & MASK1(size,0)))
  96 #define setarg(i,v,pos,size)    ((i) = (((i)&MASK0(size,pos)) | \
  97                 ((cast(Instruction, v)<<pos)&MASK1(size,pos))))
  98
  99 #define GETARG_A(i)     getarg(i, POS_A, SIZE_A)
 100 #define SETARG_A(i,v)   setarg(i, v, POS_A, SIZE_A)
 101
 102 #define GETARG_B(i)     getarg(i, POS_B, SIZE_B)
 103 #define SETARG_B(i,v)   setarg(i, v, POS_B, SIZE_B)
 104
 105 #define GETARG_C(i)     getarg(i, POS_C, SIZE_C)
 106 #define SETARG_C(i,v)   setarg(i, v, POS_C, SIZE_C)
 107
 108 #define GETARG_Bx(i)    getarg(i, POS_Bx, SIZE_Bx)
 109 #define SETARG_Bx(i,v)  setarg(i, v, POS_Bx, SIZE_Bx)
 110
 111 #define GETARG_Ax(i)    getarg(i, POS_Ax, SIZE_Ax)
 112 #define SETARG_Ax(i,v)  setarg(i, v, POS_Ax, SIZE_Ax)
 113
 114 #define GETARG_sBx(i)   (GETARG_Bx(i)-MAXARG_sBx)
 115 #define SETARG_sBx(i,b) SETARG_Bx((i),cast(unsigned int, (b)+MAXARG_sBx))
 116
 117
 118 #define CREATE_ABC(o,a,b,c)     ((cast(Instruction, o)<<POS_OP) \
 119                         | (cast(Instruction, a)<<POS_A) \
 120                         | (cast(Instruction, b)<<POS_B) \
 121                         | (cast(Instruction, c)<<POS_C))
 122
 123 #define CREATE_ABx(o,a,bc)      ((cast(Instruction, o)<<POS_OP) \
 124                         | (cast(Instruction, a)<<POS_A) \
 125                         | (cast(Instruction, bc)<<POS_Bx))
 126
 127 #define CREATE_Ax(o,a)          ((cast(Instruction, o)<<POS_OP) \
 128                         | (cast(Instruction, a)<<POS_Ax))
 129
 130
 131 /*
 132 ** Macros to operate RK indices
 133 */
 134
 135 /* this bit 1 means constant (0 means register) */
 136 #define BITRK           (1 << (SIZE_B - 1))
 137
 138 /* test whether value is a constant */
 139 #define ISK(x)          ((x) & BITRK)
 140
 141 /* gets the index of the constant */
 142 #define INDEXK(r)       ((int)(r) & ~BITRK)
 143
 144 #define MAXINDEXRK      (BITRK - 1)
 145
 146 /* code a constant index as a RK value */
 147 #define RKASK(x)        ((x) | BITRK)
 148
 149
 150 /*
 151 ** invalid register that fits in 8 bits
 152 */
 153 #define NO_REG          MAXARG_A
 154
 155
 156 /*
 157 ** R(x) - register
 158 ** Kst(x) - constant (in constant table)
 159 ** RK(x) == if ISK(x) then Kst(INDEXK(x)) else R(x)
 160 */
 161
 162
 163 /*
 164 ** grep "ORDER OP" if you change these enums
 165 */
 166
 167 typedef enum {
 168 /*----------------------------------------------------------------------
 169 name            args    description
 170 ------------------------------------------------------------------------*/
 171 OP_MOVE,/*      A B     R(A) := R(B)                                    */
 172 OP_LOADK,/*     A Bx    R(A) := Kst(Bx)                                 */
 173 OP_LOADKX,/*    A       R(A) := Kst(extra arg)                          */
 174 OP_LOADBOOL,/*  A B C   R(A) := (Bool)B; if (C) pc++                    */
 175 OP_LOADNIL,/*   A B     R(A), R(A+1), ..., R(A+B) := nil                */
 176 OP_GETUPVAL,/*  A B     R(A) := UpValue[B]                              */
 177
 178 OP_GETTABUP,/*  A B C   R(A) := UpValue[B][RK(C)]                       */
 179 OP_GETTABLE,/*  A B C   R(A) := R(B)[RK(C)]                             */
 180
 181 OP_SETTABUP,/*  A B C   UpValue[A][RK(B)] := RK(C)                      */
 182 OP_SETUPVAL,/*  A B     UpValue[B] := R(A)                              */
 183 OP_SETTABLE,/*  A B C   R(A)[RK(B)] := RK(C)                            */
 184
 185 OP_NEWTABLE,/*  A B C   R(A) := {} (size = B,C)                         */
 186
 187 OP_SELF,/*      A B C   R(A+1) := R(B); R(A) := R(B)[RK(C)]             */
 188
 189 OP_ADD,/*       A B C   R(A) := RK(B) + RK(C)                           */
 190 OP_SUB,/*       A B C   R(A) := RK(B) - RK(C)                           */
 191 OP_MUL,/*       A B C   R(A) := RK(B) * RK(C)                           */
 192 OP_MOD,/*       A B C   R(A) := RK(B) % RK(C)                           */
 193 #ifndef _KERNEL
 194 OP_POW,/*       A B C   R(A) := RK(B) ^ RK(C)                           */
 195 OP_DIV,/*       A B C   R(A) := RK(B) / RK(C)                           */
 196 #endif
 197 OP_IDIV,/*      A B C   R(A) := RK(B) // RK(C)                          */
 198 OP_BAND,/*      A B C   R(A) := RK(B) & RK(C)                           */
 199 OP_BOR,/*       A B C   R(A) := RK(B) | RK(C)                           */
 200 OP_BXOR,/*      A B C   R(A) := RK(B) ~ RK(C)                           */
 201 OP_SHL,/*       A B C   R(A) := RK(B) << RK(C)                          */
 202 OP_SHR,/*       A B C   R(A) := RK(B) >> RK(C)                          */
 203 OP_UNM,/*       A B     R(A) := -R(B)                                   */
 204 OP_BNOT,/*      A B     R(A) := ~R(B)                                   */
 205 OP_NOT,/*       A B     R(A) := not R(B)                                */
 206 OP_LEN,/*       A B     R(A) := length of R(B)                          */
 207
 208 OP_CONCAT,/*    A B C   R(A) := R(B).. ... ..R(C)                       */
 209
 210 OP_JMP,/*       A sBx   pc+=sBx; if (A) close all upvalues >= R(A - 1)  */
 211 OP_EQ,/*        A B C   if ((RK(B) == RK(C)) ~= A) then pc++            */
 212 OP_LT,/*        A B C   if ((RK(B) <  RK(C)) ~= A) then pc++            */
 213 OP_LE,/*        A B C   if ((RK(B) <= RK(C)) ~= A) then pc++            */
 214
 215 OP_TEST,/*      A C     if not (R(A) <=> C) then pc++                   */
 216 OP_TESTSET,/*   A B C   if (R(B) <=> C) then R(A) := R(B) else pc++     */
 217
 218 OP_CALL,/*      A B C   R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */
 219 OP_TAILCALL,/*  A B C   return R(A)(R(A+1), ... ,R(A+B-1))              */
 220 OP_RETURN,/*    A B     return R(A), ... ,R(A+B-2)      (see note)      */
 221
 222 OP_FORLOOP,/*   A sBx   R(A)+=R(A+2);
 223                         if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/
 224 OP_FORPREP,/*   A sBx   R(A)-=R(A+2); pc+=sBx                           */
 225
 226 OP_TFORCALL,/*  A C     R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2));  */
 227 OP_TFORLOOP,/*  A sBx   if R(A+1) ~= nil then { R(A)=R(A+1); pc += sBx }*/
 228
 229 OP_SETLIST,/*   A B C   R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B        */
 230
 231 OP_CLOSURE,/*   A Bx    R(A) := closure(KPROTO[Bx])                     */
 232
 233 OP_VARARG,/*    A B     R(A), R(A+1), ..., R(A+B-2) = vararg            */
 234
 235 OP_EXTRAARG/*   Ax      extra (larger) argument for previous opcode     */
 236 } OpCode;
 237
 238
 239 #define NUM_OPCODES     (cast(int, OP_EXTRAARG) + 1)
 240
 241
 242
 243 /*===========================================================================
 244   Notes:
 245   (*) In OP_CALL, if (B == 0) then B = top. If (C == 0), then 'top' is
 246   set to last_result+1, so next open instruction (OP_CALL, OP_RETURN,
 247   OP_SETLIST) may use 'top'.
 248
 249   (*) In OP_VARARG, if (B == 0) then use actual number of varargs and
 250   set top (like in OP_CALL with C == 0).
 251
 252   (*) In OP_RETURN, if (B == 0) then return up to 'top'.
 253
 254   (*) In OP_SETLIST, if (B == 0) then B = 'top'; if (C == 0) then next
 255   'instruction' is EXTRAARG(real C).
 256
 257   (*) In OP_LOADKX, the next 'instruction' is always EXTRAARG.
 258
 259   (*) For comparisons, A specifies what condition the test should accept
 260   (true or false).
 261
 262   (*) All 'skips' (pc++) assume that next instruction is a jump.
 263
 264 ===========================================================================*/
 265
 266
 267 /*
 268 ** masks for instruction properties. The format is:
 269 ** bits 0-1: op mode
 270 ** bits 2-3: C arg mode
 271 ** bits 4-5: B arg mode
 272 ** bit 6: instruction set register A
 273 ** bit 7: operator is a test (next instruction must be a jump)
 274 */
 275
 276 enum OpArgMask {
 277   OpArgN,  /* argument is not used */
 278   OpArgU,  /* argument is used */
 279   OpArgR,  /* argument is a register or a jump offset */
 280   OpArgK   /* argument is a constant or register/constant */
 281 };
 282
 283 LUAI_DDEC const lu_byte luaP_opmodes[NUM_OPCODES];
 284
 285 #define getOpMode(m)    (cast(enum OpMode, luaP_opmodes[m] & 3))
 286 #define getBMode(m)     (cast(enum OpArgMask, (luaP_opmodes[m] >> 4) & 3))
 287 #define getCMode(m)     (cast(enum OpArgMask, (luaP_opmodes[m] >> 2) & 3))
 288 #define testAMode(m)    (luaP_opmodes[m] & (1 << 6))
 289 #define testTMode(m)    (luaP_opmodes[m] & (1 << 7))
 290
 291
 292 LUAI_DDEC const char *const luaP_opnames[NUM_OPCODES+1];  /* opcode names */
 293
 294
 295 /* number of list items to accumulate before a SETLIST instruction */
 296 #define LFIELDS_PER_FLUSH       50
 297
 298
 299 #endif