#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