#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 simonpj): Is this really a bug at all? As Reid says, there are no guarantees about the precision of `Double`. A difference in the least significant bit of a `Double` on 64 bit vs 32 bit seems a remarkably small divergence to me. However I don't understand Reid's comment that "the optimiser is constant- folding the multiplication". Which optimiser? The user-guide link just says that some calculations are done in 80-bit without going back to 64-bit at each intermediate. Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9304#comment:26 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler