#11143: Feature request: Add index/read/write primops with byte offset for ByteArray# -------------------------------------+------------------------------------- Reporter: vagarenko | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: newcomers Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by sjakobi): * cc: sjakobi (added) Comment: Replying to [comment:2 Mathnerd314]:
Can we instead have primops which take both an offset measured in bytes and an offset measured in terms of the type? {{{#!hs indexTYPEArray# :: ByteArray# -> Int# {-byte offset-} -> Int# {-type offset-} -> TYPE# readTYPEArray# :: MutableByteArray# s -> Int# {-byte offset-} -> Int# {-type offset-} -> State# s -> (#State# s, TYPE##) writeTYPEArray# :: MutableByteArray# s -> Int# {-byte offset-} -> Int# {-type offset-} -> TYPE# -> State# s -> State# s
indexTYPEOffAddr# :: Addr# -> Int# {-byte offset-} -> Int# {-type offset-} -> TYPE readTYPEOffAddr# :: Addr# -> Int# {-byte offset-} -> Int# {-type offset-} -> State# s -> (#State# s, TYPE ##) writeTYPEOffAddr# :: Addr# -> Int# {-byte offset-} -> Int# {-type offset-} -> TYPE -> State# s -> State# s }}}
I like these types.
All of these go through the `mkBasicIndexed{Read,Write}` functions, which take both a byte offset and a type offset, so it seems reasonable to expose that.
I currently don't see how this can be done. These functions require a byte offset with type `ByteOff` (`Int`) but we only have a `CmmExpr`. It seems to me that the new primops will require quite a bit of new plumbing down to `CmmRegOff`. Am I missing something? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11143#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler