#10397: Compiler performance regression 7.6 -> 7.8 in elimCommonBlocks -------------------------------------+------------------------------------- Reporter: TobyGoodwin | Owner: Type: bug | Status: patch Priority: normal | Milestone: Component: Compiler | Version: 7.8.4 Resolution: | Keywords: Operating System: Unknown/Multiple | performance Type of failure: None/Unknown | Architecture: Blocked By: | Unknown/Multiple Related Tickets: | Test Case: see ticket | Blocking: | Differential Revisions: Phab:D892 -------------------------------------+------------------------------------- Comment (by nomeata): And just to share the joy, here a side-by-side of the profile output, before and after: {{{ Sat May 16 18:12 2015 Time and Allocation Profiling Rep| Sat May 16 18:06 2015 Time and Allocation Profiling Rep | ghc-stage2 +RTS -t -p -RTS -B/home/jojo/build/haskel| ghc-stage2 +RTS -t -p -RTS -B/home/jojo/build/haskel | total time = 198.47 secs (198467 ticks @ 1000 u| total time = 14.22 secs (14225 ticks @ 1000 us total alloc = 97,018,068,880 bytes (excludes profiling| total alloc = 14,686,848,016 bytes (excludes profiling | COST CENTRE MODULE %time %alloc | COST CENTRE MODULE %time %alloc | elimCommonBlocks CmmPipeline 80.5 69.1 | elimCommonBlocks CmmPipeline 19.9 21.2 sequenceBlocks AsmCodeGen 13.6 19.2 | SimplTopBinds SimplCore 10.6 10.2 SimplTopBinds SimplCore 0.8 1.5 | pprNativeCode AsmCodeGen 7.6 8.5 pprNativeCode AsmCodeGen 0.7 1.3 | regLiveness AsmCodeGen 7.6 6.8 regLiveness AsmCodeGen 0.5 1.0 | StgCmm HscMain 5.6 5.3 RegAlloc AsmCodeGen 0.4 1.1 | RegAlloc AsmCodeGen 5.5 7.1 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10397#comment:14 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler