#16039: 'GHC.Magic.noinline <var>' should not float out -------------------------------------+------------------------------------- Reporter: heisenbug | Owner: heisenbug Type: bug | Status: new Priority: normal | Milestone: 8.10.1 Component: Compiler | Version: 8.2.1 Resolution: | Keywords: FloatOut Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #15155 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj):
Who knows. This is a nice use-case for ASSERT().
Actally I think a little eyeballing would do the job.
Simplifier. But the mechanism by which it picks up the level variables is still a riddle for me.
It may well be "float let from let" (see the ICFP paper on let-floating). Consider {{{ let x = let y = blah in y : ys in blah2 }}} The simplifier float the `let y`, to give {{{ let y = blah in let x = y : ys in blah2 }}} This is much better because it exposes the fact that `x` is a cons. The test is done by `doFloatFromRhs` in `Simplify.hs`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16039#comment:14 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler