https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77344
--- Comment #2 from Matt Thompson <matthew.thompson at nasa dot gov> --- (In reply to Dominique d'Humieres from comment #1) > I get a lot of "*error: instruction requires: AVX-512 ISA" when compiling > gettau.F90 on x86_64-apple-darwin15, Xcode 7.3.1. I've never tried this on Darwin. It's possible the binutils, or its Apple-y/BSD-y/Clang-y equivalent, does not have support for those instructions yet? At least, errors like that scream "update binutils" in my head for some reason. I was running on RHEL 7.2. The KNL test box I have access to is...CentOS? Something like that. But this error is identical on my Haswell workstation.