Long-float variant giving more precision to numerical computations.

Raymond Toy wrote:
...
> Also, I don't think we should convert the slatec routines to use 
> long-float.  The constants there are only accurate to double-float 
> because that's all that was used when they were generated (even if the 
> original source has way more digits---an artifact of f2cl).  I think the 
> slatec routines should be compiled as normal double-float routines, and 
> the maxima interface to them should convert to/from flonum to 
> double-float as appropriate.

The slatec Fortran source comments suggests it is precise enough for
double-double float.  The code can be re-translated, maintaining the
constant precision, using the following hack patch.

F2cl hack patch to target Fortran double precision to long-float or
double-double-float:
http://www.scieneer.com/files/f2cl-patch1.txt.gz

Add the following compiler-options in slatec.system and rebuild:
  :double-precision-format kernel:double-double-float
  :float-format kernel:double-double-float

Could be a quick path if it works out.

Regards
Douglas Crosher