https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63488
--- Comment #2 from Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> --- The code in question is at libquadmath/math/j0q.c, function y0q, in the branch annotated /* 0 <= x <= 2 */ It has to do with the rational function: /* Y0(x) = 2/pi * log(x) * J0(x) + R(x^2) Peak absolute error 1.7e-36 (relative where Y0 > 1) 0 <= x <= 2 */ Coefficients are in Y0_2N and Y0_2D. -------------------- It would be useful to confirm this bug in the upstream glibc's j0l(), as it probably manifests on 128-bit long double (glibc/sysdeps/ieee754/ldbl-128/e_j0l.c).
