#9661: Branchless ==# is compiled to branchy code -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.9 Resolution: | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Unknown Type of failure: Runtime | Blocked By: performance bug | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by dfeuer): I hope that works. As a side note, we consider redefining `not` as `not x = dataToTag# (x /=# 1#)`, which should work better for branchless stuff and I ''think'' should work exactly the same for branchy stuff. That'll be one less thing I need to add to a branchless `Bool` module. I already need `complementBL x = tagToEnum# (dataToTag# `xorI#` 1#)` to play as nicely as possible with `&&!` and `||!`, I think; I'd rather not have to add `notBL` if that can replace `not` without any negative consequences. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9661#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler