Memory usage exploding for complex pattern matching
It seems like complex pattern matching is consuming a prohibitive amount of memory. From a discussion in ghc-devs, https://mail.haskell.org/pipermail/ghc-devs/2018-March/015538.html, the exhaustiveness checker could be the culprit.
We have tried with 7.10.3, 8.0.2, 8.4.1 and ghc-HEAD. They show similar results.
The "-fmax-pmchecker-iterations=0" option seems to help slightly. Bigger cases will run out of memory even with the option enabled.
I'm attaching a "minimal" example to help diagnosing. The majority of the code has been generated by Template Haskell.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 8.4.1 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
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| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |