Re: [PATCH] ieee754-h: new module

[Bruno Haible]

Hi Paul,

> It looks like Emacs can use this for some NaN processing.
> Emacs uses it only on double NaNs so it should be safe.
> * MODULES.html.sh (func_all_modules): Add ieee754-h.
> * config/srclist.txt: Mention ieee754.h in a comment.
> * doc/glibc-headers/ieee754.texi (ieee754.h):
> Gnulib now has a substitute that should work
> except for long double and for non-IEEE platforms.

I'd like to improve the reliability of this module (when time
permits).

1) You say that Emacs wants it for NaN processing. But the unit
   tests don't test NaN values, only finite values.
   Suggested action: Add tests for NaN values.

2) There may be portability issues. I'm thinking of alpha CPUs,
   possibly also s390 CPUs.
   Suggested action: #ifdef out the definitions on platforms
   where they don't work. A compilation error is better than
   garbage at runtime.

3) There are definitions for 'long double', but they are untested.
   Suggested action: Add tests for 'long double'. #ifdef out the
   definitions on platforms where they don't work.

Would you approve work in these directions?

Bruno