#7684: cgrun071 segfaults ----------------------------------+---------------------------------- Reporter: tibbe | Owner: Type: bug | Status: infoneeded Priority: normal | Milestone: 7.8.1 Component: Compiler | Version: 7.7 Resolution: | Keywords: Operating System: MacOS X | Architecture: x86_64 (amd64) Type of failure: Runtime crash | Difficulty: Unknown Test Case: cgrun071 | Blocked By: Blocking: | Related Tickets: ----------------------------------+---------------------------------- Comment (by Johan Tibell <johan.tibell@…>): In [changeset:"ad9bf96815cb5a9bb4acc51c99eff20be3e50da3/ghc-prim"]: {{{ #!CommitTicketReference repository="ghc-prim" revision="ad9bf96815cb5a9bb4acc51c99eff20be3e50da3" Make argument types in popcnt.c match declared primop types On 64-bit Mac OS, gcc 4.2 (which comes with Xcode 4.6) generates code that assumes that an argument that is smaller than the register it is passed in has been sign- or zero-extended. But ghc thinks the types of the PopCnt*Op primops are Word# -> Word#, so it passes the entire argument word to the hs_popcnt* function as though it was declared to have an argument of type StgWord. Segfaults ensue. The easiest fix is to sidestep all this zero-extension business by declaring the hs_popcnt* functions to take a whole StgWord (when their argument would fit in a register), thereby matching the list of primops. Fixes #7684. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7684#comment:52> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler