clang vs gcc on ROOT...


   as clang++ can now compile the entire ROOT framework (~3MLOC++, used for analysis of CERN LHC data) without errors in -O2 mode, it is time for some first benchmarks. Just the fact that clang compiles and runs in optimized mode is an impressive feat for such a young product, especially compared to mature compilers like gcc, icc and msvc.

Basically clang compiles up to 40% faster, produces executables that run with basically equal performance while the produced binaries are about 10% larger. Not speaking about the much better warning and error messages.
Looking forward to some more optimization performance gains.

Cheers, Fons.

Great, thanks for reporting this! (And filing lots of good bugs in the process)

  • Doug