bug-gnulib
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Bug-gnulib] [RFC] Module: long double math functions


From: Bruno Haible
Subject: Re: [Bug-gnulib] [RFC] Module: long double math functions
Date: Mon, 10 Feb 2003 20:28:10 +0100 (CET)

Paolo Bonzini writes:
> I have adapted the long double math functions (sinl & co.) in glibc so that
> they don't make any reference to the format of the numbers.  This caused a
> loss in speed and probably in accuracy as well, but it is fine for
> portability purposes.

Good. Can you put this into gnulib, together with autoconf tests that
verify the assumptions of the code? I mean: does it assume

   sizeof (long double) > sizeof (double)
   precisionof (long double) <= 2 * precisionof (double)
   IEEE format
   sizeof (long double) == 12 or == 16 ?

If you have precision problems, you can look at the algorithms of
Keith Briggs' doubledouble package (a.k.a. xdouble in LIDIA), see
http://members.lycos.co.uk/keithmbriggs/doubledouble.html
- his algorithms provide 106 bits of precision.

Bruno




reply via email to

[Prev in Thread] Current Thread [Next in Thread]