
#15103: Speed optimizations for elimCommonBlocks -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: AndreasK Type: task | Status: patch Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.5 Resolution: | Keywords: CodeGen Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D4597 Wiki Page: | -------------------------------------+------------------------------------- Comment (by AndreasK): Replying to [comment:7 simonpj]:
What is the perf impact of this optimisation, if any?
Generated code is the same. Compiler performance changes for the better. I think the file I looked at was nofib/spectral/simple `ghc-stage2 -fforce-recomp -c -O1 Main.hs +RTS -s -RTS` || build || Allocated (Byte) || measured time || || master || 4,475,812,248 || 3.220 s (3.204 s .. 3.251 s) || || toBlockList || 4,474,452,216 || 3.196 s (3.192 s .. 3.204 s) || || IntMap + blockList || 4,461,727,496 || 3.189 s (3.174 s .. 3.203 s) ||
I think the goal is to improve compile times, right? Not run-time.
Yes it's purely an "make GHC faster" patch. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15103#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler