#9304: Floating point woes; Different behavior on 32- vs 64-bit x86 -------------------------------------+------------------------------------ Reporter: lerkok | Owner: Type: bug | Status: new Priority: normal | 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 lerkok): @simonpj: I'm not sure if it's a real bug or not. There's an observed difference in behavior on 32-bit where "-O" produces a different result compared to when compiled without "-O"; and that's at least mildly disconcerting. @carter has all the context, and I think his expertise will come in handy when he gets around to spinning up a 32-bit VM and looks at it in some more detail. If he concludes this is par-for-the-course; then we can remove the ticket. I might be in the minority, but I do not think the difference in the ulp for `Double` on 64-bit vs 32-bit a remarkably small divergence.. I wish `Double` meant precisely the same thing, regardless of architecture; i.e., the 64-bit IEEE double-precision number. But I also understand that this is a minor enough concern for most Haskell users to trickle up chain of importance. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9304#comment:27 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler