HYLO fusion in GHC

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If you want to try our HYLO fusion extension to ghc-5.04.3, please contact us.

History

Features

• No need to prepare some fusable functions (eg. foldr/build).
• User defined datatype can be fused.
• And more...

Example

1. Original Haskell Program
   
2. Optimised Core Program
   Add '-fprint-core' option at last optimisation paths. You will find an new fused function named 'fun1.fun2'.
3. Executed Result
   'a.out' was compiled by original GHC. 'b.out' was compiled by our modified GHC. Please compare two heap comsumption.

Current Limitations

• No mutual recursion
• And more...

References

• A. Takano, E. Meijer. Shortcut Deforestation in Calculational Form, Proc. Conf. on Functional Programming Languages and Computer Architecture, La Jolla, California, June 1995, pp.306-313.
• Z. Hu, H. Iwasaki, M. Takeichi, Deriving Structural Hylomorphisms from Recursive Definitions, ACM SIGPLAN International Conference on Functional Programming (ICFP'96), Philadelphia, pp.73-82. May 1996. ACM Press.
• Y. Onoue, Z. Hu, H. Iwasaki, M. Takeichi, A Calculational Fusion System HYLO, IFIP TC 2 Working Conference on Algorithmic Languages and Calculi. Le Bischenberg, France. pp.76-106. February 1997. Chapman & Hall.
• Y. Onoue, Z. Hu, M. Takeichi. Implementation of Program Fusion by HYLO System. 14th Conf. Proc. Jpn. Soc. for Software Sci. and Tech., 1997, pp. 477-480 (1997) (Japanese)
• Y. Onoue, Z. Hu, H. Iwasaki, M. Takeichi. Verification for Practical Effectiveness of Program Fusion. 16th Conf. Proc. Jpn. Soc. for Software Sci. and Tech., to appeared (1999) (Japanese)