Bytecode

The bytecode instruction set is a repr(u8) enum. Operands follow instructions inline in the bytecode stream.

Instruction categories

Stack operations

LoadConst idx      push constant from pool
LoadLocal idx      push local variable
StoreLocal idx     pop into local variable
Dup                duplicate top of stack
Pop                discard top of stack

Control flow

Call argc          call function with argc arguments
TailCall argc      tail call (reuses frame)
Return             return top of stack
Jump offset        unconditional jump
JumpIfFalse offset branch if top is falsy

Arithmetic

Add                generic addition (any numeric type)
AddInt             specialized integer addition
Sub, Mul, Div      arithmetic ops
Mod, Rem           modulo and remainder
Neg                unary negation

Comparison

Eq                 structural equality
Lt, Gt, Le, Ge     ordering comparisons

Type checks

IsNil              test for nil
IsSymbol           test for symbol
IsArray            test for array

Collections

MakeArray n        construct array from n stack values
MakeStruct n       construct struct from n key-value pairs

Fiber operations

Yield              yield current fiber
Emit signal val    emit a signal

Regions

RegionEnter        begin scope allocation region
RegionExit         end scope allocation, free region objects

Encoding

Instructions are encoded as a byte stream. The opcode byte is followed by zero or more operand bytes (typically u16 or u32 indices). The LocationMap maps bytecode offsets to source locations for error reporting.

Files

src/compiler/bytecode.rs   Instruction enum and encoding