#14880: GHC panic: updateRole -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.2.2 checker) | Resolution: | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #15076 | Differential Rev(s): Phab:D4769 Wiki Page: | -------------------------------------+------------------------------------- Comment (by tdammers): Replying to [comment:53 simonpj]:
Let me urge you to try it with an explicit accumulator, exactly as I wrote it.
I recall that this made a very big difference for Bartosz.
Can you remember whether that situation involved raw `VarSet`s, or `FV`s? From what I see in the code, `FV` could, under the right circumstances, avoid hitting the underlying `IntSet` entirely, while after this patch, we're using `VarSet` directly, so maybe that's why those set operations are being hit harder now? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14880#comment:57 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler