Representation of 128 bit floating point numbers in FreeBSD amd64 and Clang

Mehmet Erol Sanliturk m.e.sanliturk at gmail.com
Thu Oct 31 15:09:23 UTC 2013


On Thu, Oct 31, 2013 at 10:38 AM, Steve Kargl <
sgk at troutmask.apl.washington.edu> wrote:

> On Thu, Oct 31, 2013 at 09:27:34AM -0400, Mehmet Erol Sanliturk wrote:
> >
> > In FreeBSD amd64 and Clang ,
> > how can I represent 128 bits ( 34 digits ) variables ?
> >
>
> Not sure it can be done with clang, but GCC supports
> a __float128 type.  GCC refers to this as its TCmode.
> gfortran, the Fortran compiler that supports REAL(16),
> uses __float128 internally.  I've never directly used
> __float128, so can't help beyond this.
>
> If you need 128-bits in C on ia32 or x86_64 hardware,
> you should probably look into using mpfr and mpc.
>
> --
> Steve
>



These are defined in the following library :

http://gcc.gnu.org/onlinedocs/libquadmath/

(  GCC libquadmath )


For printing values , the following is required :

http://gcc.gnu.org/onlinedocs/libquadmath/quadmath_005fsnprintf.html


I could not find Clang libquadmath .


Thank you very much .

Mehmet Erol Sanliturk


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