#9013: plusWord2# is buggy -------------------------------------+------------------------------------ Reporter: pumpkin | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by pumpkin): Reid Barton tracked down the culprit on IRC: https://github.com/ghc/ghc/blob/master/compiler/nativeGen/X86/Ppr.hs#L553 So it looks like: 1. it's not specific to `plusWord2#` 2. it only happens on compile-time literals (so is admittedly pretty rare) 3. it's not always sound to switch an `add` to a `dec` because the latter doesn't affect the carry flag and the former does -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9013#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler