#11792: Optimised unsafe FFI call can get wrong argument -------------------------------------+------------------------------------- Reporter: Szunti | Owner: Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 7.10.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect result | Unknown/Multiple at runtime | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2263 Wiki Page: | -------------------------------------+------------------------------------- Comment (by osa1): I was doing some reading on Cmm and found something that may be relevant in [this wiki page](https://ghc.haskell.org/trac/ghc/wiki/Commentary/Compiler/CmmType):
Global Registers in Cmm currently have a problem with inlining: because neither compiler/cmm/PprC.hs nor the NCG are able to keep Global Registers from clashing with C argument passing registers, Cmm expressions that contain Global Registers cannot be inlined into an argument position of a foreign call. For more thorough notes on inlining, see the comments in compiler/cmm/CmmOpt.hs.
The page is a bit out of date but this part sounded like the problem we're having here. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11792#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler