architecture kernel problems

[Alan]

> (Via only recently started supporting them, and AMD K6s are still used).

That bit is incorrect. VIA support the i686 instruction set correctly.
Unfortunately the GNU compiler suite generates code for i686 plus
optional cmov instruction without checks. It's a long standing compiler
bug. Originally the big benefits from building i686 were the cmov
instruction so it was deemed not worth fixing. Today cmov on the newer
cpus is a loss but the compiler people haven't fixed the bug.

Basically gcc "i686" is slighly in excess of intel defined i686.

Alan