#8972: Investigate adding fast compare-and-swap Int type/primops -------------------------------------+------------------------------------ Reporter: tibbe | Owner: tibbe Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.9 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: 8157, 7883 -------------------------------------+------------------------------------ Comment (by rrnewton): Update: I confirmed that I get the exact same time for "Data.Atomics.Counter' (atomic-primops) as I do for Johan (tibbe)'s counter.c version of the benchmark here. Johan and I talked about this and it seems like the obvious way to improve performance on this is inline primops for the fetch-and-add (#7883). We confirmed that the MutableByteArray# used by Data.Atomics.Counter is a single contiguous heap object, so the only advantage of a dedicated mutable reference type would be to save the word representing the length. More, generally, I wonder if we can have a user facing interface that makes mutable unboxed data more pleasant. Unboxed vectors are nice, but there's nothing like an (IORef (# Int#, Int# #)), for example. Even though with double-word CAS we could support some interesting data types... -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8972#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler