[GHC] #9400: poor performance when compiling modules with many Text literals at -O1

[GHC]

#9400: poor performance when compiling modules with many Text literals at -O1
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              Reporter:  rwbarton    |            Owner:
                  Type:  bug         |           Status:  closed
              Priority:  normal      |        Milestone:
             Component:  Compiler    |          Version:  7.8.3
            Resolution:  invalid     |         Keywords:
      Operating System:              |     Architecture:  Unknown/Multiple
  Unknown/Multiple                   |       Difficulty:  Unknown
       Type of failure:  Compile-    |       Blocked By:
  time performance bug               |  Related Tickets:  #9370
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
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Comment (by simonpj):

 Another possibility might be to remove the special behaviour of desugaring
 strings from GHC.  Why is it there?  I think it's in case you do
 {{{
 case "x" of
   'x' : ys -> blah
 }}}
 or something like that.  But perhaps a better plan would be to make
 `unpackCString# "foo"` respond to `exprIsConApp_maybe` with "yes, I'm a
 cons; my head is `'f'` and my tail is `unpackCString# "oo"`.

 So before making `Text` more complicated, maybe we should explore making
 GHC less complicated!

 Simon

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9400#comment:4>
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