Re: [Haskell-cafe] Safer common subexpression elimination

On Thu, Nov 25, 2010 at 2:32 AM, Joachim Breitner wrote:

So I wonder: * Is sharing values of type Int (and Bool and similar small values) always safe? * If so: does GHC already do that? * Would it be technically possible? * Is there an established theory that can tell, for a sharing candidate, whether it is safe to share it?

Jhc does this for simple types, which are unary constructors with a primitive argument (CPR types). I never actually ran tests to see how much it helps if any. John