On Wed, Mar 9, 2016 at 6:36 PM, René J.V. <rjvber...@gmail.com> wrote: > 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!
Why? My understanding is that the optimizations for -Os are equivalent to -O2 with the emphasis on size reduction. The additional optimizations from -O2 to -O3 would seem sufficient to produce a 10% execution optimization, no? > >> 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? > > ? > > R. _______________________________________________ macports-dev mailing list macports-dev@lists.macosforge.org https://lists.macosforge.org/mailman/listinfo/macports-dev
