How to use floating point in a module?

[ndiamond@despammed.com]

A driver, implemented as a module, must do some floating-point computations including trig functions.  Fortunately the architecture is x86.  A few hundred kilograms of searching (almost a ton of searching :-) seems to reveal the following possibilities.

Recompile GNU's libc with option "--without-fp".  If I understand correctly, the resulting libc will completely avoid using floating-point hardware while providing floating-point computations to its client.  Do I understand correctly?

Compile the module's .c files with gcc's "-msoft-float" option and "-D__NO_MATH_INLINES".  (Actually I think "-D__NO_MATH_INLINES" is probably unnecessary here.)

Link the module's .o files with the version of libc produced above, and try to get a loadable .ko from this... or a loadable .o since the target is still kernel 2.4.something.

But I'm sure there must be a ton of pitfalls that I'm not seeing here.  I'm not the first poor slob who got tasked with shoving some floating-point into a module.  My searches found a few tricks that people used for a few floating-point operations, but they used the real floating-point hardware and they didn't really reveal all the trickery they used.  (Not that I can blame them, since the hackery they did must be virtually unteachable.)  I didn't find anyone saying that they found a safe method of doing it, whether or not a safe method might somewhat resemble the ideas I've just presented.  I didn't find anyone saying they got trig functions into it either.  If my ideas could possibly work, surely they would have been done already.  So, what am I missing?

And does anyone know a really safe method?