Showing posts from January, 2022

Finally: long double's coming to Fedora 36

After literally years, proper support for 128-bit long double is finally arriving in Fedora 36 — and not without some churn (some of which is attributable to gcc 12), but this is a needed change to fix certain otherwise unfixable packages and the pain has to be borne sometime. The most notorious package affected by this is MAME but hopefully this work will unblock some others. Fedora 36 is scheduled for April.

Next JIT branch up

There hasn't been a lot of activity on Talospace because I've been busy on other OpenPOWER stuff. The POWER9 Firefox JIT has been transplanted to Firefox 97 (on a new branch) and compiles, links and basically runs (in the previous non-Ion configuration). Once the test suite is passing again, it's time to work on the final optimizing compiler stage hopefully in time to make Firefox 102 and the next ESR. You can help.

Firefox 96 on Power

Firefox 96 is out and after some usage of it I think I agree it's definitely lessened the load on the main thread, which is one of the lead features in this release (and our heavily multicore POWER9 systems can pick up the slack for everything else). There are also multiple improvements to HTML and CSS. Some of you with Emacs muscle memory will want to read the Developer section of the Release Notes, though (I have the Command key mapped instead so I can still use Mac muscle memory: set ui.key.accelKey to 91). Fortunately it all builds out of the box using the PGO-LTO patch and .mozconfigs from Firefox 95.

In Power ISA JIT news, the patches and JIT backend have been merged into my copy of Firefox 97 and I'm ensuring it builds and passes tests before working on the third and final stage, the optimizing compiler. This will test some code paths that haven't been tested before, so I do expect this will be slower, but we're still aiming to get this done by May in time to get into the Firefox tree for the next ESR (102). Once I have the base in, there will be a new branch on Github you can work with (and contribute to!). I'm gratified to hear from folks who have tested the current 2-stage JIT in 91ESR and it looks like it's working well. More to come soon.

Another PowerPC in space

The last POWER1 on Mars may be dead, but there are still Power ISA chips out there in space. The newest one to join them is another BAE RAD750 (a radiation-hardened PowerPC 750, the processor generation Apple called a G3) in the James Webb Space Telescope Integrated Science Instrument Module, clocked at a ripping 118MHz (.pdf) with 44MB of RAM and appears to run VxWorks. The JWST managed to flawlessly open its sunshield this weekend made from multiple layers of fragile Kapton as thin as a human hair unfolding "like origami." Can't wait to see the photos it will produce.

CentOS 8 is an ex-distro (but AlmaLinux is not)

Among the many bad things that happened in 2021 was the official end of CentOS 8, which hit EOL at the end of the calendar year (but if you were running on CentOS 7, which is POWER9-compatible, you're golden until June 2024). CentOS Stream is a thing, though, and for those of you who want something a little less, uh, bubbly than Fedora but more current than RHEL, it's an option.

Still, the loss of CentOS's celebrated stability guarantee stings, and for some of you so will the price of an RHEL subscription, which is why at least two distros sprang up to be the next "CentOS classic": Rocky Linux and AlmaLinux. Currently, Rocky Linux doesn't list a Power ISA build on its main download page or alternative architectures page. On the other hand, AlmaLinux 8.5 is now available as a beta for ppc64le (read the release notes), and claims full 1:1 binary compatibility with RHEL 8.5 to purportedly allow an almost literal drop-in experience; a single command will swap repositories and keys from CentOS 8.x. AlmaLinux states it will be supported until at least 2029.