I'd like to know if it's possible to get GHC to perform some simple CSE for function-level programming. Here's a simple example:

liftA2 (*) sin sin :: Double -> Double

which inlines and simplifies to

\ t -> sin t * sin t

A more realistic, equivalent, example:

let b = sin <$> id in liftA2 (*) b b

Can GHC be nudged into computing 'sin t' once rather than twice?

Thanks, - Conal