#9304: Floating point woes; Different behavior on Mac vs Linux -------------------------------------+------------------------------------ Reporter: lerkok | Owner: Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 7.8.3 Resolution: | Keywords: floating point Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: 9276 Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by carter): @lerkok, why is it "clearly incorrectly rounded"? I'm having trouble believing that claim. It could simply be that the way your input literals are encoded with more bits of precision in the x87 case. could you please try doing the original program as a self contained program like {{{ module Main where main = do x <- return ((-4.4)::Double) y <- return ((2.4999999999999956):: Double) putStrLn $ show $ decodeFloat (x*y) }}} compile with {{{ ghc main.hs -o -msse2 -fforce-recomp ; ./main ; ghc main.hs -o -fexcess- precision -fforce-recomp ; ./main }}} and tell us if theres a difference in the output in those two cases? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9304#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler