On Fri, Nov 03, 2017 at 12:06:15PM -0700, Kees Cook wrote:

Should a clang version test be included, since we know at least 5.0 is
need (with this fix)? There are distros with much earlier versions of
clang, for example...

Greg knows better, but I remember him mentioning that upstream clang
doesn't generate any worse code with -mno-implicit-float, so there should
be no harm in using this workaround with all versions.

This might change in future, of course, so I don't have objections to
adding a check for clang version < 6.0 here.

Sami