Compiling DynFlags is jolly slow
|Reported by:||simonpj||Owned by:||simonpj|
|Keywords:||Cc:||iustin@…, pho@…, dterei|
|Type of failure:||None/Unknown||Difficulty:||Unknown|
|Test Case:||Blocked By:|
Compiling DynFlags really takes a long time these days.
Ian thinks that it's due to the Read and Show instances he has added (see attached W2.hs.
Simon M suggests: instead of using Read/Show, you could generate some code in mkDerivedConstants to use ReadP and Outputable, which should be much smaller and faster.
This ticket is
- To see if we can speed up compilation of DynFlags
- To check WHY it is so slow. Are there any lessons we can learn or ways to make it compile faster? Is it tickling some asymptotically-bad corner of the compiler?