I'm trying to get perl580 to compile with long doubles (16 byte reals), and Configure is just not taking it. I'm using Configure -des -Dcc=xlc128 -Duse64bitint -Duselongdouble But after configure is done, there is still just uselongdouble='undef' in config.sh. I recently installed the vac.C 5.0.2.6 compiler, and I _know_ it can do 16 byte doubles by invoking it as xlc128 (which is apparently equivalent to xlc -qlongdouble -l128C). Anyone know what the problem might be? Thanks, John.Thread Next