[GHC] #16198: Cmm string literals shouldn't be represented as [Word8]

[GHC]

#16198: Cmm string literals shouldn't be represented as [Word8]
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        Reporter:  hsyl20            |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.6.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by hsyl20):

 * status:  new => patch


Comment:

 Merge request: https://gitlab.haskell.org/ghc/ghc/merge_requests/135

 Reusing the benchmark in #16190 (time to compile a file printing a string
 literal of the given size), I obtain the following results before and
 after the patch:

 || Size || Before patch    || After patch   || Gain ||
 || 128  || 0.730           || 0.732         || 0%   ||
 || 3K   || 0.731           || 0.727         || 0%   ||
 || 30K  || 0.736           || 0.714         || +3%  ||
 || 100K || 0.804           || 0.748         || +7%  ||
 || 500K || 1.038           || 0.974         || +6%  ||
 || 1M   || 1.342           || 1.157         || +14% ||
 || 2M   || 1.926           || 1.689         || +12% ||
 || 3M   || 2.539           || 2.088         || +18% ||
 || 30M  || 20.182          || 14.729        || +27% ||

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16198#comment:1>
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