[GHC] #9125: int-to-float conversion broken on ARM

[GHC]

#9125: int-to-float conversion broken on ARM
-------------------------------------+-------------------------------------
              Reporter:  Ansible     |             Owner:
                  Type:  bug         |            Status:  new
              Priority:  highest     |         Milestone:  7.8.4
             Component:  Compiler    |           Version:  7.8.3
            Resolution:              |          Keywords:
Differential Revisions:              |  Operating System:  Unknown/Multiple
          Architecture:  arm         |   Type of failure:  Incorrect result
            Difficulty:  Unknown     |  at runtime
            Blocked By:              |         Test Case:
       Related Tickets:              |          Blocking:
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Comment (by amurrayc):

 So here's a thing:

 On a hunch I switched the assignments of `r1` and `r2` in
 `stg_decodeFloatzuIntzh` so that it now reads
 {{{
       r2 = W_[mp_tmp1];
       r1 = W_[mp_tmp_w];
 }}}
 with everything else the same.

 What do you know,
 {{{
     let (m,e) = decodeFloat (29.0 :: Float)
         estr = printf "%#x" e
     putStrLn $ "(" ++ show m ++ ", " ++ estr ++ ")"
 }}}
 gives
 {{{
 (-19, 0xe80000)
 }}}
 Does that give anyone any clues?

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9125#comment:5>
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