[cfe-dev] Random clang testing results

[Sebastian Redl]

Daniel Dunbar wrote:
> I tried building Blender with clang today for fun. Went without a
> hitch, although I had to use gcc for two files from ffmpeg with nasty
> inline asm. Blender has about 600k lines of C code internally, and
> another 600k from external libraries (like FFTW, ffmpeg, qhull, ...).
How do compile times compare?
>
> Some results from comparing renders on the two binaries are here:
> http://t1.minormatter.com/~ddunbar/blender/times.html
> <http://t1.minormatter.com/%7Eddunbar/blender/times.html>
>
> A lot of rendering artifacts, but it is remotely possible this is a
> Blender bug not a clang one. Several files show obvious flaws, on the
> other hand.
These artifacts look like floating point inaccuracies to me. Could it be
that Clang generates code that makes these worse?

Sebastian