Should simplifier try more iterations?
When compiling with the devel1
build, we get debugging output while building libraries. I see a lot of warnings like this:
WARNING: file compiler/simplCore/SimplCore.hs, line 592
Simplifier bailing out after 4 iterations [5024, 247, 22, 1]
Size = {terms: 3,735, types: 3,028, coercions: 216}
It looks to me like the simplifier is doing quite a nice job and shouldn't give up so soon.
Concretely, I propose: increase the cutoff and see what the effect is on timing of running the entire GHC build, at whatever settings a performance guru thinks appropriate (almost certainly not devel1
!). Ideally, the testing would take place on ghcspeed, so that it's a controlled environment and can be compared nicely with historical performance.
I have not carried out this proposal myself because I'm not sure if there are other issues at work here (I don't know the simplifier much at all), and I don't know if there is even a way to get ghcspeed to do this for us.
Trac metadata
Trac field | Value |
---|---|
Version | 7.11 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
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Blocking | |
CC | |
Operating system | |
Architecture |