[GHC] #8922: GHC unnecessarily sign/zero-extends C call arguments

[GHC]

#8922: GHC unnecessarily sign/zero-extends C call arguments
----------------------------------+-------------------------------------
       Reporter:  simonmar        |             Owner:
           Type:  bug             |            Status:  new
       Priority:  normal          |         Milestone:  7.10.1
      Component:  Compiler (NCG)  |           Version:  7.6.3
       Keywords:                  |  Operating System:  Unknown/Multiple
   Architecture:  x86_64 (amd64)  |   Type of failure:  None/Unknown
     Difficulty:  Unknown         |         Test Case:
     Blocked By:                  |          Blocking:
Related Tickets:  #7684           |
----------------------------------+-------------------------------------
 Ticket created following discussion in
 [https://ghc.haskell.org/trac/ghc/ticket/7684#comment:58]

 It seems the zero/sign-extension that we're doing in the NCG for arguments
 less than a word in size is unnecessary, since the ABI doesn't specify any
 extension.  There's some clarification of the spec in this thread:
 [http://gcc.gnu.org/ml/gcc/2013-01/msg00448.html]

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8922>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler