double rounding in x86

[Vaughan Pratt]

	Actually it is another type of extended, one with an larger exponent
	range, but the same precision as a double.  This is the result of
	setting the precision control     register to double.

Oops, I'd forgotten that.  In that case I drop the recommendation in
the message I just sent, that x86 OS's boot up with extended precision
disabled, since this still doesn't provide double precision arithmetic
in exact-bit agreement with the rest of the world.

This would seem to make the x86 for x <= 5 a second class citizen for
scientific computing.  Anyone happen to know whether this has been
fixed on the P6?  Maybe someone with a beta-test unit can check this (I
signed up for one, don't know how they pick people).

Vaughan Pratt