was not fun and I am not entirely certain of the correctness, but it seems
to work. (in fact, side by side testing of this code vs the x86 version
turned up hidden bugs in the x86 code).
#include <ieeefp.h>
to access these functions instead of the i386 specific
#include <machine/floatingpoint.h>
Submitted by: Hidetoshi Shimokawa <simokawa@sat.t.u-tokyo.ac.jp>