#8313: Poor performance of higher-order functions with unboxing -------------------------------------+------------------------------------- Reporter: dolio | Owner: Type: task | Status: new Priority: low | Milestone: ⊥ Component: Compiler | Version: 7.6.3 Resolution: | Keywords: slow unboxed Operating System: | higher order Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: Runtime | Difficulty: Easy (less than 1 performance bug | hour) Test Case: | Blocked By: 6084 Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- Comment (by thomie): After compiling the program from comment:4 with `-O2`, `manual` is now 4x faster. {{{ $ ghc-7.8.3 -O2 T8313.hs $ ./T8313 manual +RTS -t (33333333,33333334,33333334) <<ghc: 54888 bytes, 1 GCs, 44312/44312 avg/max bytes residency (1 samples), 1M in use, 0.00 INIT (0.00 elapsed), 0.65 MUT (0.67 elapsed), 0.00 GC (0.00 elapsed) :ghc>> $ ./T8313 auto +RTS -t (33333333,33333334,33333334) <<ghc: 4800054576 bytes, 9192 GCs, 36364/44312 avg/max bytes residency (2 samples), 1M in use, 0.00 INIT (0.00 elapsed), 2.21 MUT (2.21 elapsed), 0.01 GC (0.06 elapsed) :ghc>> }}} Same results with `ghc-7.9.20141115`. Still needs that performance test. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8313#comment:5> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler