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mod instruction;
pub use instruction::Instruction;
/// Instruction format modes (Lua 5.5)
#[allow(clippy::upper_case_acronyms)]
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum OpMode {
IABC, // iABC: C(8) | B(8) | k(1) | A(8) | Op(7)
IvABC, // ivABC: vC(10) | vB(6) | k(1) | A(8) | Op(7) - variable-size B and C
IABx, // iABx: Bx(17) | A(8) | Op(7)
IAsBx, // iAsBx: sBx(signed 17) | A(8) | Op(7)
IAx, // iAx: Ax(25) | Op(7)
IsJ, // isJ: sJ(signed 25) | Op(7)
}
/// Complete Lua 5.5 Opcode Set (86 opcodes)
/// Based on lopcodes.h from Lua 5.5.0
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[repr(u8)]
pub enum OpCode {
/*----------------------------------------------------------------------
Lua 5.5 Opcode Definitions (matching lopcodes.h)
Format: name args description
------------------------------------------------------------------------*/
// Load and move operations
Move = 0, // A B R[A] := R[B]
LoadI, // A sBx R[A] := sBx
LoadF, // A sBx R[A] := (lua_Number)sBx
LoadK, // A Bx R[A] := K[Bx]
LoadKX, // A R[A] := K[extra arg]
LoadFalse, // A R[A] := false
LFalseSkip, // A R[A] := false; pc++
LoadTrue, // A R[A] := true
LoadNil, // A B R[A], R[A+1], ..., R[A+B] := nil
// Upvalue operations
GetUpval, // A B R[A] := UpValue[B]
SetUpval, // A B UpValue[B] := R[A]
// Table get operations
GetTabUp, // A B C R[A] := UpValue[B][K[C]:shortstring]
GetTable, // A B C R[A] := R[B][R[C]]
GetI, // A B C R[A] := R[B][C]
GetField, // A B C R[A] := R[B][K[C]:shortstring]
// Table set operations
SetTabUp, // A B C UpValue[A][K[B]:shortstring] := RK(C)
SetTable, // A B C R[A][R[B]] := RK(C)
SetI, // A B C R[A][B] := RK(C)
SetField, // A B C R[A][K[B]:shortstring] := RK(C)
// Table creation
NewTable, // A vB vC k R[A] := {} (ivABC format)
// Self call (method call syntax)
Self_, // A B C R[A+1] := R[B]; R[A] := R[B][K[C]:shortstring]
// Arithmetic with immediate
AddI, // A B sC R[A] := R[B] + sC
// Arithmetic with constant
AddK, // A B C R[A] := R[B] + K[C]:number
SubK, // A B C R[A] := R[B] - K[C]:number
MulK, // A B C R[A] := R[B] * K[C]:number
ModK, // A B C R[A] := R[B] % K[C]:number
PowK, // A B C R[A] := R[B] ^ K[C]:number
DivK, // A B C R[A] := R[B] / K[C]:number
IDivK, // A B C R[A] := R[B] // K[C]:number
// Bitwise operations with constant
BAndK, // A B C R[A] := R[B] & K[C]:integer
BOrK, // A B C R[A] := R[B] | K[C]:integer
BXorK, // A B C R[A] := R[B] ~ K[C]:integer
// Shift operations with immediate
ShlI, // A B sC R[A] := sC << R[B]
ShrI, // A B sC R[A] := R[B] >> sC
// Arithmetic operations (register-register)
Add, // A B C R[A] := R[B] + R[C]
Sub, // A B C R[A] := R[B] - R[C]
Mul, // A B C R[A] := R[B] * R[C]
Mod, // A B C R[A] := R[B] % R[C]
Pow, // A B C R[A] := R[B] ^ R[C]
Div, // A B C R[A] := R[B] / R[C]
IDiv, // A B C R[A] := R[B] // R[C]
// Bitwise operations (register-register)
BAnd, // A B C R[A] := R[B] & R[C]
BOr, // A B C R[A] := R[B] | R[C]
BXor, // A B C R[A] := R[B] ~ R[C]
Shl, // A B C R[A] := R[B] << R[C]
Shr, // A B C R[A] := R[B] >> R[C]
// Metamethod fallback operations
MmBin, // A B C call C metamethod over R[A] and R[B]
MmBinI, // A sB C k call C metamethod over R[A] and sB
MmBinK, // A B C k call C metamethod over R[A] and K[B]
// Unary operations
Unm, // A B R[A] := -R[B]
BNot, // A B R[A] := ~R[B]
Not, // A B R[A] := not R[B]
Len, // A B R[A] := #R[B] (length operator)
// String concatenation
Concat, // A B R[A] := R[A].. ... ..R[A + B - 1]
// Upvalue management
Close, // A close all upvalues >= R[A]
Tbc, // A mark variable A "to be closed"
// Control flow
Jmp, // sJ pc += sJ
// Comparison operations (register-register)
Eq, // A B k if ((R[A] == R[B]) ~= k) then pc++
Lt, // A B k if ((R[A] < R[B]) ~= k) then pc++
Le, // A B k if ((R[A] <= R[B]) ~= k) then pc++
// Comparison with constant/immediate
EqK, // A B k if ((R[A] == K[B]) ~= k) then pc++
EqI, // A sB k if ((R[A] == sB) ~= k) then pc++
LtI, // A sB k if ((R[A] < sB) ~= k) then pc++
LeI, // A sB k if ((R[A] <= sB) ~= k) then pc++
GtI, // A sB k if ((R[A] > sB) ~= k) then pc++
GeI, // A sB k if ((R[A] >= sB) ~= k) then pc++
// Conditional tests
Test, // A k if (not R[A] == k) then pc++
TestSet, // A B k if (not R[B] == k) then pc++ else R[A] := R[B]
// Function calls
Call, // A B C R[A], ... ,R[A+C-2] := R[A](R[A+1], ... ,R[A+B-1])
TailCall, // A B C k return R[A](R[A+1], ... ,R[A+B-1])
// Return operations
Return, // A B C k return R[A], ... ,R[A+B-2]
Return0, // return
Return1, // A return R[A]
// Numeric for loops
ForLoop, // A Bx update counters; if loop continues then pc-=Bx;
ForPrep, // A Bx <check values and prepare counters>; if not to run then pc+=Bx+1;
// Generic for loops
TForPrep, // A Bx create upvalue for R[A + 3]; pc+=Bx
TForCall, // A C R[A+4], ... ,R[A+3+C] := R[A](R[A+1], R[A+2])
TForLoop, // A Bx if R[A+2] ~= nil then { R[A]=R[A+2]; pc -= Bx }
// Table list initialization
SetList, // A vB vC k R[A][vC+i] := R[A+i], 1 <= i <= vB (ivABC format)
// Closure creation
Closure, // A Bx R[A] := closure(KPROTO[Bx])
// Vararg operations
Vararg, // A B C k R[A], ..., R[A+C-2] = varargs
GetVarg, // A B C R[A] := R[B][R[C]], R[B] is vararg parameter (Lua 5.5)
// Error checking for globals (Lua 5.5)
ErrNNil, // A Bx raise error if R[A] ~= nil (K[Bx - 1] is global name)
// Vararg preparation
VarargPrep, // (adjust varargs)
// Extra argument for previous instruction
ExtraArg, // Ax extra (larger) argument for previous opcode
// Reserved opcodes fill the remaining 7-bit space so the hot dispatch
// table can cover 0..=127 without a per-instruction range check.
Reserved85, // reserved (never emitted by the compiler)
Reserved86, // reserved (never emitted by the compiler)
Reserved87, // reserved (never emitted by the compiler)
Reserved88, // reserved (never emitted by the compiler)
Reserved89, // reserved (never emitted by the compiler)
Reserved90, // reserved (never emitted by the compiler)
Reserved91, // reserved (never emitted by the compiler)
Reserved92, // reserved (never emitted by the compiler)
Reserved93, // reserved (never emitted by the compiler)
Reserved94, // reserved (never emitted by the compiler)
Reserved95, // reserved (never emitted by the compiler)
Reserved96, // reserved (never emitted by the compiler)
Reserved97, // reserved (never emitted by the compiler)
Reserved98, // reserved (never emitted by the compiler)
Reserved99, // reserved (never emitted by the compiler)
Reserved100, // reserved (never emitted by the compiler)
Reserved101, // reserved (never emitted by the compiler)
Reserved102, // reserved (never emitted by the compiler)
Reserved103, // reserved (never emitted by the compiler)
Reserved104, // reserved (never emitted by the compiler)
Reserved105, // reserved (never emitted by the compiler)
Reserved106, // reserved (never emitted by the compiler)
Reserved107, // reserved (never emitted by the compiler)
Reserved108, // reserved (never emitted by the compiler)
Reserved109, // reserved (never emitted by the compiler)
Reserved110, // reserved (never emitted by the compiler)
Reserved111, // reserved (never emitted by the compiler)
Reserved112, // reserved (never emitted by the compiler)
Reserved113, // reserved (never emitted by the compiler)
Reserved114, // reserved (never emitted by the compiler)
Reserved115, // reserved (never emitted by the compiler)
Reserved116, // reserved (never emitted by the compiler)
Reserved117, // reserved (never emitted by the compiler)
Reserved118, // reserved (never emitted by the compiler)
Reserved119, // reserved (never emitted by the compiler)
Reserved120, // reserved (never emitted by the compiler)
Reserved121, // reserved (never emitted by the compiler)
Reserved122, // reserved (never emitted by the compiler)
Reserved123, // reserved (never emitted by the compiler)
Reserved124, // reserved (never emitted by the compiler)
Reserved125, // reserved (never emitted by the compiler)
Reserved126, // reserved (never emitted by the compiler)
Reserved127, // reserved (never emitted by the compiler)
}
impl OpCode {
#[inline(always)]
pub fn from_u8(byte: u8) -> Self {
if byte <= OpCode::ExtraArg as u8 {
// SAFETY: We check that the byte is within the valid range of opcodes before transmuting
unsafe { std::mem::transmute::<u8, OpCode>(byte) }
} else {
OpCode::Reserved127
}
}
/// Unchecked opcode decoding for the hot interpreter dispatch.
///
/// # Safety: `byte` must be a valid opcode discriminant in `0..=127`.
/// Bytecode produced by this compiler only ever contains valid opcodes.
#[inline(always)]
pub fn from_u8_unchecked(byte: u8) -> Self {
debug_assert!(byte <= 127);
unsafe { std::mem::transmute::<u8, OpCode>(byte) }
}
/// Check if instruction uses "top" (IT mode - In Top)
/// These instructions depend on the value of 'top' from previous instruction
/// For all other instructions, top should be reset to base + nactvar
///
/// From Lua 5.5 lopcodes.c:
/// - CALL: IT=1 (uses top for vararg count)
/// - TAILCALL: IT=1
/// - RETURN: IT=1 (uses top for return count)
/// - SETLIST: IT=1 (uses top for list size)
/// - VARARGPREP: IT=1 (sets up varargs)
pub fn uses_top(self) -> bool {
use OpCode::*;
matches!(self, Call | TailCall | Return | SetList | VarargPrep)
}
/// Get the instruction format mode for this opcode
/// Based on Lua 5.5 lopcodes.c luaP_opmodes table
pub fn get_mode(self) -> OpMode {
use OpCode::*;
match self {
// iAsBx format (signed Bx)
LoadI | LoadF => OpMode::IAsBx,
// iABx format (unsigned Bx)
LoadK | LoadKX | ForLoop | ForPrep | TForPrep | TForLoop | Closure | ErrNNil => {
OpMode::IABx
}
// isJ format (signed jump)
Jmp => OpMode::IsJ,
// iAx format
ExtraArg => OpMode::IAx,
// ivABC format (variable-size B and C fields)
NewTable | SetList => OpMode::IvABC,
// iABC format (everything else)
_ => OpMode::IABC,
}
}
}