[Bug 106053] Drawing at screen boundary is very slow.

https://bugs.freedesktop.org/show_bug.cgi?id=106053

--- Comment #3 from Roland Scheidegger sroland@vmware.com --- (In reply to Marek Olšák from comment #2)

r300g on RC410 uses software emulation for vertex shaders and clipping (the same code as llvmpipe), because the hardware doesn't have any vertex processor and clipper.

Can't the chip do guardband clipping? I thought all radeon chips (starting from r100) could do this, regardless if they support hw tnl. I could be wrong though (and I wouldn't know how large the guardband would be, and certainly draw's handling of guardband if you enable it is a bit lacking, since hw has fixed limits whereas draw will use a guardband twice the size of the viewport).