[Cfp-interest 2698] Re: Floating point rounding modes

[Paul Zimmermann]

       Dear Hans,

> Pretty much the rest of the committee preferred the simplest possible
> library solution, i.e. free functions that operate directly on float and
> double, with an explicit rounding mode argument. I plan to write that up. I
> would expect such a solution to be C compatible, if there is interest.

this would be incompatible with the large effort currently done in the
CORE-MATH project, which builds upon the ISO C standard for using rounding
in mathematical functions:

   double x, y;
   fesetround (FE_TOWARDZERO);
   y = sin (x); /* or y = cr_sin(x) */

You write-up should explain how to avoid throwing away this work
(without loosing cycles).

Best regards,
Paul

PS: if you only plan to suggest modifications in the C++ standard (not the
C standard), please ignore this message.