#15002: Panic: collectNBinders -------------------------------------+------------------------------------- Reporter: crockeea | Owner: nomeata Type: bug | Status: patch Priority: highest | Milestone: 8.4.2 Component: Profiling | Version: 8.4.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D4572 Wiki Page: | -------------------------------------+------------------------------------- Comment (by nomeata): Ah, things are never easy. Yes, adding `noCSE` in the right places is the right thing to do, and it fixes this bug. But as often when fixing a “bug” in an optimization, it makes it less aggressive, and we get regressions: {{{ Nofib allocations nofib/allocs/rewrite 16255960 + 5.52% 17153208 bytes nofib/allocs/scs 902408848 + 5.22% 949533296 bytes Nofib instruction counts nofib/instr/rewrite 55292296 + 4.73% 57910048 Testsuite allocations tests/alloc/T8766 16828080 + 348.94% 75548336 bytes }}} Did not investigate anything yet (it’s 1am here). -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15002#comment:13 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler