#2450: Data.Complex.magnitude squares using ^(2 :: Int), which is slow --------------------------------------------+------------------------------ Reporter: igloo | Owner: Type: bug | Status: new Priority: lowest | Milestone: 7.6.2 Component: libraries/base | Version: 6.8.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime performance bug | Unknown/Multiple Test Case: | Difficulty: Unknown Blocking: | Blocked By: | Related Tickets: --------------------------------------------+------------------------------ Comment (by cdk): It looks like this has been resolved, `Data.Complex.magnitude` now uses `sqr z = z * z` and `GHC.Real` has rewrite rules for small, known constant exponents: https://github.com/ghc/packages-base/blob/master/Data/Complex.hs https://github.com/ghc/packages-base/blob/master/GHC/Real.lhs I found this bug on the list of 'getting started' bugs, but it's already been fixed. Time to close? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/2450#comment:14 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler