Wrapped calls to functions from Voidware's CORDIC implementation here: http://www.voidware.com/cordic.htm . This project handles the domain issues stated in the comments.
The effect is some reasonably precise special functions with compile size much smaller than their equivalents in <math.h>, albeit a bit slower.
To use in your project, bring the following files in:
cordic.c, cordic.h, cordic_consts.c, cordic_wrapped.c, cordic_wrapped.h
Add cordic.c and cordic_wrapped.c to your makefiles, and to include use #include cordic_wrapped.h.
To run some precision tests against equivalent functions in <math.h>, compile test_math.c:
$ cc -lm ./cordic.c ./cordic_wrapped.c ./test_math.c
$ ./a.out
To regenerate constants, see cordic_consts.c.
- Fix
atan_wc's imprecision for extreme values - Add more thorough tests in
test_math.c