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IRHash: Efficient Multi-Language Compiler Caching by IR-Level Hashing

31 points by matt_d

by orlp

3 subcomments

Every developer I've talked to has had the same experience with compilation caches as me: they're great. Until one day you waste a couple hours of your time chasing a bug caused by a stale cache. From that point on your trust is shattered, and there's always a little voice in the back of your head when debugging something which says "could this be caused by a stale cache?". And you turn it off again for peace of mind.

by meisel

1 subcomments

Very interesting stuff. However, for my day-to-day work, I'm in a large C++ code base where most of the code has to be in headers due to templating. The bottlenecks are, very roughly:
- Header parsing (40% of time)
- Template instantiation (40% of time)
- Backend (20% of time)
For my use case, it seems like this cache would only kick in when 80% of the work has already been done. Ccache, on the other hand, doesn't require any of that work to be done. On a sidenote, template instantiation caching is a very interesting strategy, but today's compilers don't use it (there was some commercially sold compiler a while back that did have it, though).

by curtisszmania

0 subcomment