https://bugs.freedesktop.org/show_bug.cgi?id=91193
--- Comment #5 from Michel Dänzer michel@daenzer.net --- (In reply to Sebastian Parborg from comment #4)
I'm guessing that this is just a temporary workaround?
No, I think it's the proper fix. TGSI_SEMANTIC_CLIPDIST values are also passed to the pixel shader as a varying, so they need to be counted here.
I'll submit the patch to the mesa-dev mailing list for review.