Optimisation: Nested CPR
GHC currently cannot unbox the result of a function in the IO monad. For example:
facIO :: Int -> IO Int
facIO n = if n < 2 then return 1 else do n' <- facIO (n-1); return (n*n')the Int argument is unboxed fine, but not the result. It ought to be possible to do this: the CPR analysis needs to somehow look inside the unboxed pair returned by IO-monadic code.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 6.6.1 |
| Type | Task |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | Unknown |
| Architecture | Unknown |
Edited by Sebastian Graf