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 /* ** \$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<>1) /* `sBx' is signed */ #else #define MAXARG_Bx MAX_INT #define MAXARG_sBx MAX_INT #endif #define MAXARG_A ((1<>POS_OP) & MASK1(SIZE_OP,0))) #define SET_OPCODE(i,o) ((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \ ((cast(Instruction, o)<>POS_A) & MASK1(SIZE_A,0))) #define SETARG_A(i,u) ((i) = (((i)&MASK0(SIZE_A,POS_A)) | \ ((cast(Instruction, u)<>POS_B) & MASK1(SIZE_B,0))) #define SETARG_B(i,b) ((i) = (((i)&MASK0(SIZE_B,POS_B)) | \ ((cast(Instruction, b)<>POS_C) & MASK1(SIZE_C,0))) #define SETARG_C(i,b) ((i) = (((i)&MASK0(SIZE_C,POS_C)) | \ ((cast(Instruction, b)<>POS_Bx) & MASK1(SIZE_Bx,0))) #define SETARG_Bx(i,b) ((i) = (((i)&MASK0(SIZE_Bx,POS_Bx)) | \ ((cast(Instruction, b)< 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)*/ 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