Mix

Interpolate between x and y using a.

(module
  (func $mix (export "mix") (param $x f32) (param $y f32) (param $a f32) (result f32)
    (f32.add
      (f32.mul 
        (get_local $x) 
        (f32.sub 
          (f32.const 1)
          (get_local $a)
        )
      )
      (f32.mul 
        (get_local $y)
        (get_local $a)
      )
    )
  )
)