type unop = | Neg| Abs| Ceil| Floor| Trunc| Nearest| Sqrt
type binop = | Add| Sub| Mul| Div| Min| Max| CopySign
type relop = | Eq| Ne| Lt| Gt| Le| Ge
type cvtop = | ConvertSI32| ConvertUI32| ConvertSI64| ConvertUI64| PromoteF32| DemoteF64| ReinterpretInt