Could you please tell me how to check the precision of long double in GCC on different platforms?
Thank you! Cong On Tue, Sep 3, 2013 at 2:43 PM, Joseph S. Myers <jos...@codesourcery.com> wrote: > On Tue, 3 Sep 2013, Xinliang David Li wrote: > >> >From Joseph: >> >> "The >> conversion is not safe for sqrt if the two types are double and long >> double and long double is x86 extended, for example." >> >> This is not reflected in the patch. > > No, the problem is that it tries to reflect it but hardcodes the specific > example I gave, rather than following the logic I explained regarding the > precisions of the types involved, which depend on the target. And since I > only gave a simplified analysis, for two types when this function deals > with cases involving three types, the patch submission needs to include > its own analysis for the full generality of three types to justify the > logic used (as inequalities involving the three precisions). (I suspect > it reduces to the case of two types so you don't need to go into the > details of reasoning about floating point to produce the more general > analysis. But in any case, it's for the patch submitter to give the full > explanation.) > > -- > Joseph S. Myers > jos...@codesourcery.com
