Okay, based on recent questions about libc and math fp emul, I still
have a few questions.

Kernel questions:
1) If you have a 486DX with a math fpu, do you want or need the npx line
   in the kernel config?

2) If you have this line, will fpu instructions invoke it, despite the
   fact you have hardware to do it?

Library questions:

1) Currently, to get the math libraries (libm) to compile right, you
   must edit the libm makefile.  What is the diff here?
   If you do not use i387 in this makefile, does it do emulation with
   integer code or something, or what?  It is somehow unoptimal to
   simply use the same routines and simply emulate the unimplemented
   fp instructions in the kernel?

2) If the answer to #1 above was that we should do integer code emulation
   in the library routines (or in some other way have the lib routines
   differ based on the kernel configuration), what is the optimal way
   to do this?  Should it ask the kernel about its configuration at
   run-time?  sysctl?
   Or should we tie in the kernel generation to library development
   so that the libraries pick up the kernel configuration details like
   CPU, etc.