Opened 21 months ago

Last modified 11 months ago

#14870 new bug

Runtime performance regression in 8.4

Reported by: bgamari Owned by:
Priority: normal Milestone: 8.10.1
Component: Compiler Version: 8.4.1-alpha3
Keywords: Cc:
Operating System: Unknown/Multiple Architecture: Unknown/Multiple
Type of failure: Runtime performance bug Test Case:
Blocked By: Blocking:
Related Tickets: Differential Rev(s):
Wiki Page:


varosi reports that the code for his project is slower in 8.4.1 than 8.2.2:

Yesterday I successfully compiled it with GHC 8.4.1-rc1. I got compiled it with 8.2.2 and 8.0.2 as well and ran tests for about a minute each on my Intel Core i7 machine on Windows 10 x64.

I got this results:

GHC 8.4.1-rc1 Average time: 61.87s

GHC 8.2.2 Average time: 60.09s

GHC 8.0.2 Average time: 67.07s

We should look into why.

Change History (3)

comment:1 Changed 21 months ago by bgamari

Milestone: 8.6.1

comment:2 Changed 17 months ago by bgamari


These won't be addressed in GHC 8.6.

comment:3 Changed 11 months ago by osa1


Bumping milestones of low-priority tickets.

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