On Fri, 4 Jan 2019 at 15:32, Peng Yu <pengyu.ut@xxxxxxxxx> wrote: > > The options are the same for this purpose. I am just running the test > on Mac OS X. But I could use Linux as well. I don't think the results > are different. I don't care what OS you're using, I only care what compiler you're using. You're not using GCC, you're using Clang pretending to be GCC. That's still not GCC, it's Clang.