[GHC] #9577: String literals are wasting space

[GHC]

#9577: String literals are wasting space
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              Reporter:  xnyhps      |            Owner:  xnyhps
                  Type:  bug         |           Status:  new
              Priority:  low         |        Milestone:
             Component:  Compiler    |          Version:  7.8.2
  (NCG)                              |         Keywords:
            Resolution:              |     Architecture:  Unknown/Multiple
      Operating System:              |       Difficulty:  Unknown
  Unknown/Multiple                   |       Blocked By:
       Type of failure:  Runtime     |  Related Tickets:
  performance bug                    |
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
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Comment (by rwbarton):

 If I have a server today that serves a large literal ByteString in
 response to a particular request, presumably that string buffer will get
 copied out of at some point—maybe even by the kernel. That memcpy probably
 won't have statically known size or alignment but it probably will
 determine at runtime that the size is large and alignment is suitable for
 doing a more efficient copy.

 Replying to [comment:10 xnyhps]:
 > Alternatively, using the same heuristic as GCC would also be an option:
 align only ≥32 byte strings. (`genCCall` has a maximum length it will
 unroll, but I can't tell what that practically is on x86.)

 I think we should just do this (at least for now).

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9577#comment:11>
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