[GHC] #8472: Primitive string literals prevent optimization

[GHC]

#8472: Primitive string literals prevent optimization
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        Reporter:  akio              |                Owner:  gridaphobe
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.6.3
      Resolution:                    |             Keywords:  newcomer
Operating System:  Linux             |         Architecture:  x86_64
 Type of failure:  Runtime           |  (amd64)
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by gridaphobe):

 * owner:  xnyhps => gridaphobe


Comment:

 @simonpj I'm working on this and have a patch nearly ready, but I'm a bit
 confused by your suggestion (in comment:1) to update `CmmLint`. It's not
 clear to me how to check this at the `Cmm` level, how do we determine what
 is top level?

 Perhaps you meant to check the invariant in `CoreLint`? I'm having to
 tweak a few of the checks there anyway that expect all top-level binders
 to have lifted types.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8472#comment:8>
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