[GHC] #15569: Constant folding optimises 1 into 3

[GHC]

#15569: Constant folding optimises 1 into 3
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        Reporter:  snowleopard       |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.6.1-beta1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #9136             |  Differential Rev(s):  Phab:D5109
       Wiki Page:                    |
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Comment (by sgraf):

 @jean, I'm not particularly invested in the field, but on page 6 in the
 report I linked there is a table of superoptimizers (I confused these with
 supercompilation in the past, which is totally different), the respective
 papers of which might be a good start. In particular, everything doing
 "synthesis" is probably fueled by an SMT solver.

 I think the essence boils down to formalising source and target language
 (which should be same algebraic structure in our example) and let the SMT
 solver synthesize a RHS to a given LHS expression which has minimal cost
 wrt. some metric. This seems like the most recent approach:
 https://arxiv.org/pdf/1711.04422.pdf

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15569#comment:22>
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