Example where ghc 6.10.1 fails to optimize recursive instance function calls
Using ghc 6.10.1, I get over a 3x performance boost on the attached toy example, by moving instance function definitions out of the instance declaration, so that recursive calls avoid the class dictionary.
According to SPJ, ghc 6.10.1 is supposed to perform this optimization automatically. I am reporting it as a bug at his request, following a discussion on the glasgow-haskell-users@haskell.org list.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 6.10.1 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
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