#10571: GHC 7.10.1 segfaults when shiftL-ing Integers by negative amounts -------------------------------------+------------------------------------- Reporter: anders_ | Owner: Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 7.10.1 Resolution: | Keywords: Operating System: MacOS X | Architecture: x86_64 Type of failure: Runtime crash | (amd64) Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by rwbarton): I know `unsafeShiftL` has "unsafe" in the name, but it seems irresponsible to segfault on a negative argument when it would take one additional instruction to test for a negative shift (`shiftLInteger` already checks whether the shift is 0) in a function that is not cheap to begin with and is exposed as a "public" part of the `Data.Bits` API. The `Int` instance of `unsafeShiftL` is sensible because the cost of testing whether the shift is in range could exceed the cost of actually doing the shift. That doesn't apply here to `Integer`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10571#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler