port:libclang (and libLLVM)

René J.V. Bertin rjvbertin at gmail.com
Wed Mar 9 15:36:29 PST 2016

On Wednesday March 09 2016 18:00:07 Jack Howarth wrote:

> Have you checked to make sure that the installed llvm packages aren't
> built as the +assertions variant? The use of assertions will have a

Oh yes. With that variant active the performance hit is much worse from what I recall, so I've been making a point of it only to install release versions, without assertions active.

> 3.8.0. However, port isn't smart enough to honor that change for
> previous installations of llvm-3.8 so the +assertions variant will

I wouldn't call the user who doesn't notice that all of a sudden a clang/llvm upgrade takes hours because built from source particularly bright either ;)

> slower than the same under the fink packaging of llvm38/clang38 but
> the fink packaging uses the default -O3 optimization whereas MacPorts
> resets the build to use -Os instead,

Frankly I'd be surprised if that leads to a 10% performance difference!

> Also, keep in mind that each release of clang has been getting slower
> over time as discussed in this thread...

Indeed, which is why I compared comparable versions in the past; my "up to 50%" estimate is based on that.

> > Is there a reason the LLVM ports build a shared libLLVM?



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