[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 xnyhps):

 Yeah, I have Windows and Linux available to test on. Other architectures
 (PPC/ARM/...) not as easily, so I'll keep the generated code for those
 unchanged.

 Gathering up some discussion from GCC about alignment of string literals:

 * https://gcc.gnu.org/ml/gcc/2002-01/msg01068.html
 * https://gcc.gnu.org/ml/gcc-patches/2004-01/msg02835.html:

 {{{
         * config/i386/i386.c (ix86_constant_alignment): Decrease alignment
         of long string literals from 32 bytes to sizeof (void *) when !-Os
         and to 1 with -Os.
 }}}
 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=22158

 The main argument in favor of alignment seems to be: code often `memcpy`s
 string literals into buffers. By doing that with aligned addresses
 (apparently) SSE instructions can be used. This is irrelevant for GHC,
 because the strings are only parsed into `[Char]`s, never copied.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9577#comment:3>
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