https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64470
--- Comment #2 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- The definition of DBL_MAX_EXP (and thereby GCC's __DBL_MAX_EXP__) in C11 is "maximum integer such that FLT_RADIX raised to one less than that power is a representable finite floating-point number, e_max". Note the "one less than".
