Adding __float128 (i.e TS 18661-3)

[Florian Weimer]

On 05/06/2016 01:55 AM, Joseph Myers wrote:
> On Thu, 5 May 2016, Joseph Myers wrote:
>
>> Working out the exact set of additions to the ABI and the API is the most
>> critical thing to get consensus on.
>
> I should add: it's also the thing where it's most important to get views
> from a range of glibc developers in the discussion, not simply to rely on
> my views as libm maintainer of appropriate interfaces.  New interfaces,
> especially large sets of new interfaces as here, are an area where a wider
> consensus is desirable than just agreement of the relevant subsystem
> maintainer with lack of specific objections stated by anyone else.

I find it very difficult to comment on this because I don't know how the 
existing ldbl framework works.

I assume it is used to implement a C version of C++ function templates 
such as

   template <class LongDoubleType> int
   vfprintf (FILE *s, const CHAR_T *format, va_list ap);
22
calling other function templates like

   template <class LongDoubleType> int
   __printf_fp_l (FILE *fp, locale_t loc,
                  const struct printf_info *info,
                  const void *const *args);

with a matching LongDoubleType argument.  But I don't know how it works 
in detail, and how unintended spillover between different copies is 
prevented.  (C++ has name mangling for that.)

Florian