[GHC] #11808: nofib's cryptarithm1 regresses due to deferred inlining of Int's Ord operations

#11808: nofib's cryptarithm1 regresses due to deferred inlining of Int's Ord operations -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: task | Status: new Priority: highest | Milestone: 8.0.1 Component: Compiler | Version: 8.0.1-rc3 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Runtime Unknown/Multiple | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Commit d1179c4bff6d05cc9e86eee3e2d2cee707983c90 [[https://perf.haskell.org/ghc/#revision/d1179c4bff6d05cc9e86eee3e2d2cee707983c90|apparently]] causes a ~5% regression in runtime in nofib's `cryptarithm1` benchmark. Need to work out why. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11808 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#11808: nofib's cryptarithm1 regresses due to deferred inlining of Int's Ord operations -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: task | Status: new Priority: highest | Milestone: 8.0.1 Component: Compiler | Version: 8.0.1-rc3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): Check out allocation figures.. do they budge? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11808#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#11808: nofib's cryptarithm1 regresses due to deferred inlining of Int's Ord operations -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: task | Status: new Priority: highest | Milestone: 8.0.1 Component: Compiler | Version: 8.0.1-rc3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): I have not been able to reproduce the regression locally, unfortunately. I did a nofib run prior to merging the commit which as far as I remember didn't show any major regressions; moreover my attempt at reproducing the issue this morning came up (or rather, the change supposedly **improved** runtime by 1.7%, although I don't believe this is significant). Regardless, according to ghc-speed (which you can reveal by clicking on the `=` button in the top right corner) the patch didn't change allocations. Judging by the [[https://perf.haskell.org/ghc/#graph/nofib/time/cryptarithm1;hl=d1179c4bff6d05cc9e86eee3e2d2cee707983c90|history]] of this benchmark it seems to be quite unstable. This could be due to a number of things, including caching effects. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11808#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#11808: nofib's cryptarithm1 regresses due to deferred inlining of Int's Ord operations -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: task | Status: new Priority: high | Milestone: 8.0.2 Component: Compiler | Version: 8.0.1-rc3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * priority: highest => high * milestone: 8.0.1 => 8.0.2 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11808#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#11808: nofib's cryptarithm1 regresses due to deferred inlining of Int's Ord operations -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: task | Status: closed Priority: high | Milestone: 8.0.2 Component: Compiler | Version: 8.0.1-rc3 Resolution: worksforme | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by thomie): * status: new => closed * resolution: => worksforme Comment: This was the change that perf.h.o reported: {{{ nofib/time/cryptarithm1 0.401 + 4.99% 0.421 seconds }}} Since cryptarithm1's runtime is currently under 0.4 seconds again on perf.h.o, I think it's safe to close this ticket, and call it an anomaly. {{{ nofib/time/cryptarithm1 0.397 = 0.397 seconds }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11808#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
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