https://issues.dlang.org/show_bug.cgi?id=23677
--- Comment #1 from John Hall <john.michael.h...@gmail.com> --- It looks like my previous comment about CEPHES is in error. What is actually happening is that the logImpl function has the CEPHES polynomials that are used for log1p (at least I know it's true for doubles, I don't see them in the CEPHES code for floats/long double, but I assume it is right). In other words, the phobos log function seems to try to be more accurate for values close to 1 in a way that is different from other programming languages (which is why log1p is typically included as a separate function). I'm still showing some funky results for log1p(1.0e-15) vs. log1p(1.0e-16) compared to when log1p did the calculation at real accuracy. --
