https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70117
Alan Modra <amodra at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |amodra at gmail dot com --- Comment #3 from Alan Modra <amodra at gmail dot com> --- > while with GCC, we get: > > high double: 7FEFFFFF FFFFFFFF > low double: 7C8FFFFF FFFFFFFE Right. This is 0x1.fffffffffffff7ffffffffffff8p+1023 gnulib isn't correct here. As the comment says the high double must be the value of the long double correctly rounded to double (to nearest since that is the only mode supported for IBM extended double). Any long double value higher than the above will round up the high double to inf.