Note that there are a variety of known x86-64 abi issues. If llvm-gcc code is trying to call into gcc code, this could be a problem.

Is this fixed now? x86-64 abi should be mostly happy.

Currently the build fails because of llvm/llvm-bugzilla-archive#2556 (at -O2 and -O0).
I haven't been able to improve the Ada x86-64 situation because
of this.

Previously I was able to build at -O0. Looking at Ada test
suite failures then indicated that indeed there were a bunch
of ABI problems, eg: wrong handling of functions returning
arrays (which I guess got forgotten about since C-like languages
don't do that). I have local patches fixing some of them but
even so it wasn't enough to get Ada building at -O2 at that
time.

is this fixed or even worth keeping open if not?

I'm planning on fixing this kind of issue in dragonegg, but not in llvm-gcc.

mentioned in issue llvm/llvm-bugzilla-archive#2556