#7258: Compiling DynFlags is jolly slow -------------------------------------+------------------------------------- Reporter: simonpj | Owner: simonpj Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.1 Resolution: | Keywords: deriving-perf Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): Very curious. I see in comment:79 {{{ Before total time = 26.00 secs (25996 ticks @ 1000 us, 1 processor) total alloc = 14,921,627,912 bytes (excludes profiling overheads) After total time = 13.31 secs (13307 ticks @ 1000 us, 1 processor) total alloc = 15,772,184,488 bytes (excludes profiling overheads) }}} I don't think I have ever before seen a program that actually allocates more (15G instead of 14G) and yet runs in half the time. Usually allocation and runtime are more or less correlated. But apparently not in this case. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/7258#comment:81 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler