long double support in cygwin

J. Johnston jjohnstn@cygnus.com
Wed Nov 15 09:08:00 GMT 2000

Stephen L Moshier wrote:
> >I do not know if the original math package from Sun ever had long
> > double support
> It did not.  It did not have single precision, either.  What you have
> there for `float' routines are arbitrarily redeclared versions of the
> double precision codes -- if I may say, not a very efficient design
> for small embedded computers.
> > contributions / patches to newlib are welcome.
> > Note that newlib cannot accept any GPL or proprietary code.
> What I would propose to do for printf and scanf is very similar
> to an appendix for DJGPP that you can look at in
>   http://www.simtel.net/pub/simtelnet/gnu/djgpp/v2tk/smldbl12.zip
> It is based on a program that I placed in the public domain 7 or 8 years
> ago.  GCC uses that same program for its binary <-> decimal conversion.
> DJGPP uses it to generate test vectors for libm functions.
> It meets the requirements of IEEE 754 and IEEE 854 for conversion
> accuracy.  The routines can be configured for any of the usual
> precisions up through 128-bit long double.
> Since an externally maintained printf-scanf patch would have to be
> updated whenever you change your sources, I hope that you will be
> willing to install something officially to provide the long double
> conversions.


I agree that something permanent is the answer and I will start working on 
a patch to the current sources based on the code you have provided.

-- Jeff Johnston (Red Hat Inc.)

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