https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96711
--- Comment #12 from B Eggen <bre08 at eggen dot co.uk> --- Thanks for your explanations, and for reminding me of the excellent library etc by David Bailey. My original quest was to have a fast method to decide for large integers quickly whether they are perfect squares. I prob need to do something different to avoid the rounding pitfalls (:-) PS (and maybe I need to post this separately as a suggestion) - will there be a fast "octuple-precision floating point / integer" library (i.e. 256 bit) for C, C++ and Fortran, or is using something like GMP the only way forward ? BW, Bernd