While profiling a math-intensive application, I discovered that libm,
(as built by a 1.4.2 'make release'), uses software rather than
hardware based math functions, at least with sqrt.

Digging deeper revealed "i387_LIBM" in mk.conf controls this, and
recompiling a FPU-savvy math library made an incredible difference in
FP performance. (My satellite predictor program now runs 3 times
faster with no differences in output...)

Is there any reason the port doesn't use this by default?
(Particularly with FPUs being IEEE754/854.) At the very least,
I387_LIBM should be documented somewhere (aside from the 1.3-1.4
ChangeLog).

Let me know if this should not be pr'd.
-- 
Chris Baird,, <cjb@brushtail.apana.org.au>