#14815: -XStrict prevents code inlining. -------------------------------------+------------------------------------- Reporter: danilo2 | Owner: (none) Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 8.2.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by osa1): So the bug here is not related with inlining. In general, any flag that effects generated Core (or analysis passes like the demand analysis) can effect inlining decisions. In particular, -XStrict can lead to more case expressions to evaluate intermediate results eagerly, which may cause larger code, which effects inlining decisions. Also, because some part of inlining decisions are done in the use site we'd also need to see the code that uses your `primitive` function. That being said, the bug here is that `-XStrict` shouldn't have any effect on generated Core because you only have one binding (`a` in your `primitive` function), and that has a laziness annotation. [https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/glasgow_exts... #strict-by-default-pattern-bindings GHC user manual on -XStrict] says that adding `~` in front of bindings gives us the regular lazy behavior. So really there's nothing `-XStrict` can do in this module. However the desugared code really changes with `-XStrict` in GHC 8.2.2, and that's the bug. I just tested with HEAD and 8.4 RC1 and this is fixed in both versions so you just have to update GHC when 8.4 released. (I don't know if there will be another 8.2 release, if so maybe we can include the fix in that version) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14815#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler