If this section needs an example then (given MarkK's observation about
the i387) then either d10v's two stack pointers or the SH's bank
registers. Neither of these are especially complicated.
But... but the IA-32's FP and MMX hair is, like, the canonical
motivation for the cooked/raw distinction. You've said repeatedly
that a GDB developer needs to understand this distinction. That makes
it a *good* example, right? I think it's one of the best ---
especially since it's something familiar to a lot more people than the
d10v and the SH.
The original motivation for this model was work by David Taylor for an
architecture that dual ported all of memory (memory == register).
Additional motivations came from SH4 (sh5 proved the model), d10v and
MIPS. The i386 was but a blip on the horizon.