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Diffstat (limited to 'src/lopcodes.h')
-rw-r--r-- | src/lopcodes.h | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/src/lopcodes.h b/src/lopcodes.h new file mode 100644 index 0000000..41224d6 --- /dev/null +++ b/src/lopcodes.h @@ -0,0 +1,268 @@ +/* +** $Id: lopcodes.h,v 1.125.1.1 2007/12/27 13:02:25 roberto Exp $ +** Opcodes for Lua virtual machine +** See Copyright Notice in lua.h +*/ + +#ifndef lopcodes_h +#define lopcodes_h + +#include "llimits.h" + + +/*=========================================================================== + We assume that instructions are unsigned numbers. + All instructions have an opcode in the first 6 bits. + Instructions can have the following fields: + `A' : 8 bits + `B' : 9 bits + `C' : 9 bits + `Bx' : 18 bits (`B' and `C' together) + `sBx' : signed Bx + + A signed argument is represented in excess K; that is, the number + value is the unsigned value minus K. K is exactly the maximum value + for that argument (so that -max is represented by 0, and +max is + represented by 2*max), which is half the maximum for the corresponding + unsigned argument. +===========================================================================*/ + + +enum OpMode {iABC, iABx, iAsBx}; /* basic instruction format */ + + +/* +** size and position of opcode arguments. +*/ +#define SIZE_C 9 +#define SIZE_B 9 +#define SIZE_Bx (SIZE_C + SIZE_B) +#define SIZE_A 8 + +#define SIZE_OP 6 + +#define POS_OP 0 +#define POS_A (POS_OP + SIZE_OP) +#define POS_C (POS_A + SIZE_A) +#define POS_B (POS_C + SIZE_C) +#define POS_Bx POS_C + + +/* +** limits for opcode arguments. +** we use (signed) int to manipulate most arguments, +** so they must fit in LUAI_BITSINT-1 bits (-1 for sign) +*/ +#if SIZE_Bx < LUAI_BITSINT-1 +#define MAXARG_Bx ((1<<SIZE_Bx)-1) +#define MAXARG_sBx (MAXARG_Bx>>1) /* `sBx' is signed */ +#else +#define MAXARG_Bx MAX_INT +#define MAXARG_sBx MAX_INT +#endif + + +#define MAXARG_A ((1<<SIZE_A)-1) +#define MAXARG_B ((1<<SIZE_B)-1) +#define MAXARG_C ((1<<SIZE_C)-1) + + +/* creates a mask with `n' 1 bits at position `p' */ +#define MASK1(n,p) ((~((~(Instruction)0)<<n))<<p) + +/* creates a mask with `n' 0 bits at position `p' */ +#define MASK0(n,p) (~MASK1(n,p)) + +/* +** the following macros help to manipulate instructions +*/ + +#define GET_OPCODE(i) (cast(OpCode, ((i)>>POS_OP) & MASK1(SIZE_OP,0))) +#define SET_OPCODE(i,o) ((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \ + ((cast(Instruction, o)<<POS_OP)&MASK1(SIZE_OP,POS_OP)))) + +#define GETARG_A(i) (cast(int, ((i)>>POS_A) & MASK1(SIZE_A,0))) +#define SETARG_A(i,u) ((i) = (((i)&MASK0(SIZE_A,POS_A)) | \ + ((cast(Instruction, u)<<POS_A)&MASK1(SIZE_A,POS_A)))) + +#define GETARG_B(i) (cast(int, ((i)>>POS_B) & MASK1(SIZE_B,0))) +#define SETARG_B(i,b) ((i) = (((i)&MASK0(SIZE_B,POS_B)) | \ + ((cast(Instruction, b)<<POS_B)&MASK1(SIZE_B,POS_B)))) + +#define GETARG_C(i) (cast(int, ((i)>>POS_C) & MASK1(SIZE_C,0))) +#define SETARG_C(i,b) ((i) = (((i)&MASK0(SIZE_C,POS_C)) | \ + ((cast(Instruction, b)<<POS_C)&MASK1(SIZE_C,POS_C)))) + +#define GETARG_Bx(i) (cast(int, ((i)>>POS_Bx) & MASK1(SIZE_Bx,0))) +#define SETARG_Bx(i,b) ((i) = (((i)&MASK0(SIZE_Bx,POS_Bx)) | \ + ((cast(Instruction, b)<<POS_Bx)&MASK1(SIZE_Bx,POS_Bx)))) + +#define GETARG_sBx(i) (GETARG_Bx(i)-MAXARG_sBx) +#define SETARG_sBx(i,b) SETARG_Bx((i),cast(unsigned int, (b)+MAXARG_sBx)) + + +#define CREATE_ABC(o,a,b,c) ((cast(Instruction, o)<<POS_OP) \ + | (cast(Instruction, a)<<POS_A) \ + | (cast(Instruction, b)<<POS_B) \ + | (cast(Instruction, c)<<POS_C)) + +#define CREATE_ABx(o,a,bc) ((cast(Instruction, o)<<POS_OP) \ + | (cast(Instruction, a)<<POS_A) \ + | (cast(Instruction, bc)<<POS_Bx)) + + +/* +** Macros to operate RK indices +*/ + +/* this bit 1 means constant (0 means register) */ +#define BITRK (1 << (SIZE_B - 1)) + +/* test whether value is a constant */ +#define ISK(x) ((x) & BITRK) + +/* gets the index of the constant */ +#define INDEXK(r) ((int)(r) & ~BITRK) + +#define MAXINDEXRK (BITRK - 1) + +/* code a constant index as a RK value */ +#define RKASK(x) ((x) | BITRK) + + +/* +** invalid register that fits in 8 bits +*/ +#define NO_REG MAXARG_A + + +/* +** R(x) - register +** Kst(x) - constant (in constant table) +** RK(x) == if ISK(x) then Kst(INDEXK(x)) else R(x) +*/ + + +/* +** grep "ORDER OP" if you change these enums +*/ + +typedef enum { +/*---------------------------------------------------------------------- +name args description +------------------------------------------------------------------------*/ +OP_MOVE,/* A B R(A) := R(B) */ +OP_LOADK,/* A Bx R(A) := Kst(Bx) */ +OP_LOADBOOL,/* A B C R(A) := (Bool)B; if (C) pc++ */ +OP_LOADNIL,/* A B R(A) := ... := R(B) := nil */ +OP_GETUPVAL,/* A B R(A) := UpValue[B] */ + +OP_GETGLOBAL,/* A Bx R(A) := Gbl[Kst(Bx)] */ +OP_GETTABLE,/* A B C R(A) := R(B)[RK(C)] */ + +OP_SETGLOBAL,/* A Bx Gbl[Kst(Bx)] := R(A) */ +OP_SETUPVAL,/* A B UpValue[B] := R(A) */ +OP_SETTABLE,/* A B C R(A)[RK(B)] := RK(C) */ + +OP_NEWTABLE,/* A B C R(A) := {} (size = B,C) */ + +OP_SELF,/* A B C R(A+1) := R(B); R(A) := R(B)[RK(C)] */ + +OP_ADD,/* A B C R(A) := RK(B) + RK(C) */ +OP_SUB,/* A B C R(A) := RK(B) - RK(C) */ +OP_MUL,/* A B C R(A) := RK(B) * RK(C) */ +OP_DIV,/* A B C R(A) := RK(B) / RK(C) */ +OP_MOD,/* A B C R(A) := RK(B) % RK(C) */ +OP_POW,/* A B C R(A) := RK(B) ^ RK(C) */ +OP_UNM,/* A B R(A) := -R(B) */ +OP_NOT,/* A B R(A) := not R(B) */ +OP_LEN,/* A B R(A) := length of R(B) */ + +OP_CONCAT,/* A B C R(A) := R(B).. ... ..R(C) */ + +OP_JMP,/* sBx pc+=sBx */ + +OP_EQ,/* A B C if ((RK(B) == RK(C)) ~= A) then pc++ */ +OP_LT,/* A B C if ((RK(B) < RK(C)) ~= A) then pc++ */ +OP_LE,/* A B C if ((RK(B) <= RK(C)) ~= A) then pc++ */ + +OP_TEST,/* A C if not (R(A) <=> C) then pc++ */ +OP_TESTSET,/* A B C if (R(B) <=> C) then R(A) := R(B) else pc++ */ + +OP_CALL,/* A B C R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */ +OP_TAILCALL,/* A B C return R(A)(R(A+1), ... ,R(A+B-1)) */ +OP_RETURN,/* A B return R(A), ... ,R(A+B-2) (see note) */ + +OP_FORLOOP,/* A sBx R(A)+=R(A+2); + if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/ +OP_FORPREP,/* A sBx R(A)-=R(A+2); pc+=sBx */ + +OP_TFORLOOP,/* A C R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2)); + if R(A+3) ~= nil then R(A+2)=R(A+3) else pc++ */ +OP_SETLIST,/* A B C R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B */ + +OP_CLOSE,/* A close all variables in the stack up to (>=) R(A)*/ +OP_CLOSURE,/* A Bx R(A) := closure(KPROTO[Bx], R(A), ... ,R(A+n)) */ + +OP_VARARG/* A B R(A), R(A+1), ..., R(A+B-1) = vararg */ +} OpCode; + + +#define NUM_OPCODES (cast(int, OP_VARARG) + 1) + + + +/*=========================================================================== + Notes: + (*) In OP_CALL, if (B == 0) then B = top. C is the number of returns - 1, + and can be 0: OP_CALL then sets `top' to last_result+1, so + next open instruction (OP_CALL, OP_RETURN, OP_SETLIST) may use `top'. + + (*) In OP_VARARG, if (B == 0) then use actual number of varargs and + set top (like in OP_CALL with C == 0). + + (*) In OP_RETURN, if (B == 0) then return up to `top' + + (*) In OP_SETLIST, if (B == 0) then B = `top'; + if (C == 0) then next `instruction' is real C + + (*) For comparisons, A specifies what condition the test should accept + (true or false). + + (*) All `skips' (pc++) assume that next instruction is a jump +===========================================================================*/ + + +/* +** masks for instruction properties. The format is: +** bits 0-1: op mode +** bits 2-3: C arg mode +** bits 4-5: B arg mode +** bit 6: instruction set register A +** bit 7: operator is a test +*/ + +enum OpArgMask { + OpArgN, /* argument is not used */ + OpArgU, /* argument is used */ + OpArgR, /* argument is a register or a jump offset */ + OpArgK /* argument is a constant or register/constant */ +}; + +LUAI_DATA const lu_byte luaP_opmodes[NUM_OPCODES]; + +#define getOpMode(m) (cast(enum OpMode, luaP_opmodes[m] & 3)) +#define getBMode(m) (cast(enum OpArgMask, (luaP_opmodes[m] >> 4) & 3)) +#define getCMode(m) (cast(enum OpArgMask, (luaP_opmodes[m] >> 2) & 3)) +#define testAMode(m) (luaP_opmodes[m] & (1 << 6)) +#define testTMode(m) (luaP_opmodes[m] & (1 << 7)) + + +LUAI_DATA const char *const luaP_opnames[NUM_OPCODES+1]; /* opcode names */ + + +/* number of list items to accumulate before a SETLIST instruction */ +#define LFIELDS_PER_FLUSH 50 + + +#endif |