[GHC] #7460: Double literals generated bad core

[GHC]

#7460: Double literals generated bad core
---------------------------------+------------------------------------------
    Reporter:  tibbe             |       Owner:                         
        Type:  bug               |      Status:  new                    
    Priority:  normal            |   Milestone:                         
   Component:  Compiler          |     Version:  7.4.2                  
    Keywords:                    |          Os:  Unknown/Multiple       
Architecture:  Unknown/Multiple  |     Failure:  Runtime performance bug
  Difficulty:  Unknown           |    Testcase:                         
   Blockedby:                    |    Blocking:                         
     Related:                    |  
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Comment(by igloo):

 What's the regression exactly? In 7.0 I see
 {{{
               case GHC.Prim.>=# i#_a1x8 0 of _ {
                 GHC.Bool.False ->
                   case {__pkg_ccall_GC integer-gmp
 integer_cmm_word2Integerzh GHC.Prim.Word#
                                                        -> (#
 GHC.Prim.Int#, GHC.Prim.ByteArray# #)}_a1yc
                          x#_a16l
                   of _ { (# s1_a1y9, d_a1ya #) ->
                   case {__pkg_ccall integer-gmp integer_cbits_encodeDouble
 GHC.Prim.Int#
                                                     -> GHC.Prim.ByteArray#
                                                     -> GHC.Prim.Int#
                                                     -> GHC.Prim.State#
 GHC.Prim.RealWorld
                                                     -> (# GHC.Prim.State#
 GHC.Prim.RealWorld,
                                                           GHC.Prim.Double#
 #)}_a1yl
                          s1_a1y9 d_a1ya 0 GHC.Prim.realWorld#
 }}}
 as opposed to
 {{{
               case GHC.Prim.>=# i#_a1F4 0 of _ {
                 GHC.Types.False ->
                   case GHC.Integer.Type.doubleFromInteger
                          (GHC.Integer.Type.wordToInteger x#_a1iv)
 }}}
 in 7.4. Is that change what you are talking about, or are you looking at
 something different?

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7460#comment:7>
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