寄存器
Instruction Notation
R(A)
Register A (specified in instruction field A)
R(B)
Register B (specified in instruction field B)
R(C)
Register C (specified in instruction field C)
PC
Program Counter
Kst(n)
Element n in the constant list
Upvalue[n]
Name of upvalue with index n
Gbl[sym]
Global variable indexed by symbol sym
RK(B)
Register B or a constant index
RK(C)
Register C or a constant index
sBx
Signed displacement (in field sBx) for all kinds of jumps
Instruction Summary
Lua bytecode instructions are 32-bits in size. 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
'Ax' : 26 bits ('A', 'B', and 'C' together)
'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.
操作码
| Opcode | Description |
|---|---|
| MOVE | Copy a value between registers |
| LOADK | Load a constant into a register |
| LOADKX | Load a constant into a register |
| LOADBOOL | Load a boolean into a register |
| LOADNIL | Load nil values into a range of registers |
| GETUPVAL | Read an upvalue into a register |
| GETTABUP | Read a value from table in up-value into a register |
| GETTABLE | Read a table element into a register |
| SETTABUP | Write a register value into table in up-value |
| SETUPVAL | Write a register value into an upvalue |
| SETTABLE | Write a register value into a table element |
| NEWTABLE | Create a new table |
| SELF | Prepare an object method for calling |
| ADD | Addition operator |
| SUB | Subtraction operator |
| MUL | Multiplication operator |
| MOD | Modulus (remainder) operator |
| POW | Exponentation operator |
| DIV | Division operator |
| IDIV | Integer division operator |
| BAND | Bit-wise AND operator |
| BOR | Bit-wise OR operator |
| BXOR | Bit-wise Exclusive OR operator |
| SHL | Shift bits left |
| SHR | Shift bits right |
| UNM | Unary minus |
| BNOT | Bit-wise NOT operator |
| NOT | Logical NOT operator |
| LEN | Length operator |
| CONCAT | Concatenate a range of registers |
| JMP | Unconditional jump |
| EQ | Equality test, with conditional jump |
| LT | Less than test, with conditional jump |
| LE | Less than or equal to test, with conditional jump |
| TEST | Boolean test, with conditional jump |
| TESTSET | Boolean test, with conditional jump and assignment |
| CALL | Call a closure |
| TAILCALL | Perform a tail call |
| RETURN | Return from function call |
| FORLOOP | Iterate a numeric for loop |
| FORPREP | Initialization for a numeric for loop |
| TFORLOOP | Iterate a generic for loop |
| TFORCALL | Initialization for a generic for loop |
| SETLIST | Set a range of array elements for a table |
| CLOSURE | Create a closure of a function prototype |
| VARARG | Assign vararg function arguments to registers |