ARITY ANALYSIS (Working Notes Only, Not Ready for Publication Yet)

Virtually every compiler performs transformations on the program it is compiling in an attempt to improve efficiency. However, a transformation known as “lambda floating” has not received much attention in the past. In this paper we describe an analysis on the arity of a function which determines the number of lambdas that can be floated out. We give detailed measurements of the effect in an optimising compiler for the higher-order polymorphic functional language Haskell. Our results show that it is an important transformation offering an average reduction of 5% in execution time.