Opened 2 years ago

Last modified 2 years ago

#14383 new bug

Allocation in VS up 500%

Reported by: nomeata Owned by:
Priority: low Milestone:
Component: Compiler Version: 8.3
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:


Somewhere in between the commits fee253fc and 99c61e22 nofib’s VS benchmark has allocations increased by 500%. is currently defuct (linker errors due to recent changes to the ffi stuff, I believe Moritz is trying to find that out), so I cannot just look there to see which commit broke it. But maybe someone feels like bisecting this.

If not maybe will be able to tell us once its fixed (although keeping up with GHC commits there is a bit of a pain these days.)

Change History (3)

comment:1 Changed 2 years ago by nomeata

I can restrict the problem to the range 33452dfc..99c61e22 (only 340 commits left)

comment:2 Changed 2 years ago by simonpj

Where is nofib's VS benchmark? What's the latest released compiler with good perf? 8.2? 8.0?

comment:3 Changed 2 years ago by nomeata

It’s in real/eff/VS, just added this August, so no released compiler has it in the suite.

But I can of course test an old compiler with make NoFibRuns=1 mode=slow HC=ghc-8.0. I get

8.0       483117568
8.2       483117520
7ea5d41d 3123117584
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