Re: Can GMP be replaced by trees?

[Tobias Schlüter <tobias dot schlueter at physik dot uni-muenchen dot de>]

Paul Brook wrote:
> > By changing the core GCC code (for anything more than +-*/) to use MPFR,
> > rather than going the other way, support for folding particular functions
> > is naturally shared by all languages supporting those functions - for
> > example, you get constant folding for most of the C99 <math.h> and
> > <complex.h> functions "for free" (as MPFR already implements computing
> > 0.5ulp correctly rounded values for those functions).  (You also fix the
> > well-known problem that sqrtl can be folded with incorrect rounding on
> > systems with 106-bit long double.)  Contributions to MPFR to support
> > functions not already supported help more than just GCC.
>
>
> This would be my preferred solution.
>
> Tobi: The existing routines for real arithmetic are in real.{c,h}, and do not 
> involve tree nodes. These would probably be useable as a replacement for GMP. 
> However I think the best solution would be to convert everything to use MPFR 
> as described above.

Ok, (I missed that gcc's real.[ch] don't operate on trees).

I openend PR 15515 which is meant to track any efforts in that 
direction. We can change this to a non-Fortran bug if people think that 
the benefit of this work is not specific to Fortran.

- Tobi