#11146: Manual eta expansion leads to orders of magnitude less allocations -------------------------------------+------------------------------------- Reporter: niteria | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- While working on deterministic free variable computation I run into some performance issues. I narrowed it down to code that when eta expanded performed less allocations. I ended up writing a benchmark and for large examples the eta expanded versions performs orders of magnitude less allocations. The results of my test: {{{ EtaExpanded test3 50,450,112 bytes allocated in the heap real 0.89 EtaReduced test3 3,661,740,240 bytes allocated in the heap real 3.66 }}} The whole source is here: https://github.com/niteria/deterministic-fvs, I'm also attaching the two interesting implementations. I experimented with it a little and GHC eta-expanded when I didn't have mutually recursive bindings. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11146 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler