Source file fixnum.ml

open Base
open Hardcaml
include Fixnum_intf

module Make (Spec : Spec) = struct
  type t = int

  let width = Spec.width
  let to_scaled_int t = t
  let round x = Float.to_int (if Float.(x < 0.) then x -. 0.5 else x +. 0.5)
  let scale = 2. **. Float.of_int Spec.fractional_width
  let of_float x = round (x *. scale)
  let to_float t = Float.of_int t /. scale
  let of_bits bits = bits |> Bits.to_sint
  let to_bits t = Bits.of_int ~width t
  let constb t = t |> to_bits |> Bits.to_bstr
  let pow2 i = Int.( lsl ) 1 (Spec.fractional_width + i)
  let bits_constf f = f |> of_float |> to_bits

  let signal_mul a b =
    Signal.(select (sra (a *+ b) Spec.fractional_width) (Spec.width - 1) 0)
  ;;

  let signal_constf f = Signal.of_int ~width (f |> of_float)
end