It's not a matrix of the ONLY platforms which CAN work. Is that what you're thinking? Other platforms might well need the porting abstraction layer to be implemented (the Intel compiler might offer a different set of atomic intrinsics, for example), but that's what it's there for.
In any case, I did re-review the library today and I'll still pass on it because I'm very opinionated about C and this library doesn't match my opinions.
And I would like to see ARM64 support before I depend on this sort of thing, too, for what it's worth.
However, this is certainly not fully explanitative, and of course is just one line immediately above a large and eye-catching matrix.
I will change it, to make it more clear, and more eye-catching.
Regarding ARM64, it's something I want very much. I will finally have time for it now 7.1.0 is out. I Googled a bit just the other day and there are Pi-like ARM64 dev boards out there now, so I'm going to get one.
Which leaves me needing a SPARC dev board, and a POWERPC dev board, and an x86 dev board, and a MIPS64 dev board, and a... :-)
http://elinux.org/Test_Lab_Architecture
to test on someone else's hardware?
I applied to the GCC compiler farm late last year, but received a reply only after so long a time that I'd deleted the key pair I'd submitted because I thought nothing was going to happen - and my efforts to get back in have yet been unanswered.
The GCC compile farm isn't for intensive testing or benchmarking, though (which is what you need for lock-free, to try to catch race conditions) - that test lab sounds more interesting.
I have to say though having your own dev boards which are yours and only yours and which you can hammer endlessly is very convenient. It's actually just occurred to me I can leave all the devs boards permanently running the test suite...
OTOH, I don't think I can get small, portable dev boards for all the platforms I care about, so at least for some architectures, a third-party farm is probably the only way.
Probably the most pressing requirement though is access to a Mac. Right now there are no build files for that platform.