https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108068
--- Comment #5 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- For DFP it's not just zero for which you can't infer an equivalence of values from an equality comparison; any finite value that can be represented with more than one quantum exponent (any value that can be represented with less precision than the type, unless it can only be represented with the largest or smallest possible quantum exponent) has the same property. So handling DFP zero here probably isn't enough to avoid bugs.
