mbNoXORClipping - what's this needed for?

[Tor Lillqvist]

> I would not mind, nope - would surely get us less obtuse code. Would
> be good though to check if not indeed e.g. X11 benefits.

You mean, like actually doing measurements to see if there is any
benefit, or too significant performance hit, in wallclock time, or
CPU/GPU utilisation, etc, for some typical workload on various kinds
of CPUs/graphics hardware/distros/drivers? Yeah, right. In other
words, better not touch it? ;)

--tml