🚀 go-pugleaf

This isn't exactly a cryptographic problem, but I suspect sci.crypt is the
best place to ask.

What I need is a very very fast random number generator; it does NOT need to
be cryptographically strong.  The application is in generating random noise
for dithering a color image.  I need about 8 random bits on each call
(randomness of the low order bits is less important than the higher).
Ideally it would take, say, just a shift and XOR per value.  The code has to
be portable C, so circular shifts and other non-C operations are out.

I think something along the lines of a shift register with a constant
pattern XORed in after every shift might solve my problem.  But I don't
know how to design such a thing.  Info or references would be appreciated.

			thanks, tom lane