[GHC] #8354: Add INLINE (or at least INLINABLE) pragmas for methods of Ord in ghc-prim

[GHC]

#8354: Add INLINE (or at least INLINABLE) pragmas for methods of Ord in ghc-prim
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              Reporter:  guest       |            Owner:  ekmett
                  Type:  feature     |           Status:  new
  request                            |        Milestone:
              Priority:  normal      |          Version:  7.6.3
             Component:  Core        |         Keywords:  ghc-prim
  Libraries                          |     Architecture:  Unknown/Multiple
            Resolution:              |       Difficulty:  Unknown
      Operating System:              |       Blocked By:
  Unknown/Multiple                   |  Related Tickets:
       Type of failure:              |
  None/Unknown                       |
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
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Comment (by dfeuer):

 I'm wondering if we should revert the `Eq` and `Ord` specialization for
 `String` and instead try to have some fun with fusion, doing something
 much like what we do with `foldr2`. If I'm not mistaken,

 {{{#!hs
 xs == ys = foldr go null xs ys
   where
     go _x _r [] = False
     go  x  r (z:zs)
       | x == z    = r zs
       | otherwise = False
 }}}

 {{{#!hs
 compare xs ys = foldr go (bool LT EQ . null) xs ys
   where
     go _x _r [] = GT
     go  x  r (z:zs) =
       case compare x z of
         LT -> LT
         GT -> GT
         EQ -> r zs
 }}}

 and similarly (carefully) reversing the roles of `xs` and `ys`.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8354#comment:6>
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