[GHC] #11731: Simplifier: Inlining trivial let can lose sharing

[GHC]

#11731: Simplifier: Inlining trivial let can lose sharing
-------------------------------------+-------------------------------------
        Reporter:  nomeata           |                Owner:
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D2064
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by simonpj):

 > I wonder: What else (besides the code-generator) uses the used-once
 information in a critical way? In particular, `isUsedOnce` is *only*
 mentioned in `CoreToStg`. Should we even bother removing the information
 then?

 I think nothing.  And that's why I said it's optional to erase it.  It's
 just a little smelly to have info in the tree that is wrong.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11731#comment:33>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler