[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:D2073
       Wiki Page:                    |
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Comment (by nomeata):

 Very nice results due to the final demand analyzer:
 {{{
 nofib/allocs/cichelli   80313656        - 22.92%        61907656
 bytes
 nofib/allocs/mandel2    1041544         - 11.40%        922768  bytes
 nofib/time/cryptarithm1 0.421            - 5.23%        0.399   seconds
 tests/alloc/T9233       1030551552       + 3.61%        1067738016
 bytes
 tests/alloc/T9675       574886360        + 5.26%        605104208
 bytes
 }}}
 (I hope they are not too good to be true).

 The regressions in the two test cases are compiler benchmarks; I think
 this is the expected cost for another run of the demand analyzer.

 Left to do for this ticket: Remove the (unused, possibly wrong) `1*`
 annotations in the Worker/Wrapper-Phase.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11731#comment:43>
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