Futhark.Optimise.Simplify.ClosedForm

This module implements facilities for determining whether a reduction or fold can be expressed in a closed form (i.e. not as a SOAC).

Right now, the module can detect only trivial cases. In the future, we would like to make it more powerful, as well as possibly also being able to analyse sequential loops.

Documentation

foldClosedForm :: (ASTLore lore, BinderOps lore) => VarLookup lore -> Pattern lore -> Lambda lore -> [SubExp] -> [VName] -> RuleM lore ()

foldClosedForm look foldfun accargs arrargs determines whether each of the results of foldfun can be expressed in a closed form.

loopClosedForm :: (ASTLore lore, BinderOps lore) => Pattern lore -> [(FParam lore, SubExp)] -> Names -> SubExp -> Body lore -> RuleM lore ()

loopClosedForm pat respat merge bound bodys determines whether the do-loop can be expressed in a closed form.

type VarLookup lore = VName -> Maybe (Exp lore, Certificates)

A function that, given a variable name, returns its definition.