#10491: Regression, simplifier explosion with Accelerate, cannot compile, increasing tick factor is not a workaround -------------------------------------+------------------------------------- Reporter: robertce | Owner: Type: bug | Status: new Priority: highest | Milestone: 7.10.2 Component: Compiler | Version: 7.10.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by George): ghc -V The Glorious Glasgow Haskell Compilation System, version 7.10.1.20150612 It seems that the order of the args determines if it succeeds or not. {{{ time ghc -fno-specialise -fforce-recomp -O2 Slice.hs [1 of 1] Compiling Data.Array.Accelerate.CUDA.Array.Slice ( Slice.hs, Slice.o ) ghc: panic! (the 'impossible' happened) (GHC version 7.10.1.20150612 for x86_64-apple-darwin): Simplifier ticks exhausted When trying UnfoldingDone $j_s1FS5 To increase the limit, use -fsimpl-tick-factor=N (default 100) If you need to do this, let GHC HQ know, and what factor you needed To see detailed counts use -ddump-simpl-stats Total ticks: 1668604 Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug real 0m19.542s user 0m18.451s sys 0m0.901s bash-3.2$ time ghc -O2 -fno-specialise -fforce-recomp Slice.hs [1 of 1] Compiling Data.Array.Accelerate.CUDA.Array.Slice ( Slice.hs, Slice.o ) real 0m3.299s user 0m3.085s sys 0m0.158s }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10491#comment:29 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler