The Computer Languages and System Software (CLaSS) group at Lawrence Berkeley National Laboratory is proud to announce the release of UPC++ 2025.10.0, now available from upcxx.lbl.gov. This release introduces enhancements and usability improvements, as detailed in the ChangeLog and copied below.
Please use the issue tracker to report any problems or make feature requests. Alternatively, if you have private feedback or questions not suited to a public venue, you can email: gasnet...@lbl.gov. We welcome all feedback.
We maintain public installs of UPC++ on NERSC Perlmutter, OLCF Frontier and ALCF Aurora, with usage instructions here. The 2025.10.0 release will be installed on the listed systems some time next week.
The 2023.9.0 revisions of the UPC++ Specification and the UPC++ Programmer's Guide remain current.
-Paul H. Hargrove, on behalf of the CLaSS group at LBNL
ChangeLog excerpts for this release:
NEW: Experimental APIs for immediate-mode RPC communication, to help avoid injection stalls in the presence of network congestion.
See implementation-defined.md for more details.
General features/enhancements: (see specification and programmer's guide for full details)
Updated upcxx-run supports launch of smp-conduit jobs via ssh, MPI and PMI on supported systems, matching the capabilities of (for instance) ibv and ofi.
Infrastructure changes:
Support for the Cray XC platform and its aries network, deprecated since 2023.9.0, have been removed.
Correction to install script enables use of LLVM/clang++ version 20 and higher
Newer embedded GASNet-EX resolves various issues seen when using:
GNU Compiler Collection (GCC) version 15.1.0, and newer
AMD ROCm version 6.0, and newer
HPE's Slingshot Host Software (SHS) version 12.0.1, and newer
Download filenames and their md5 checksums:
upcxx-2025.10.0.tar.gz 011a52c55fe2f09482664a2be0b06cf6
upcxx-spec-2023.9.0.pdf ac203c910ad6d133d44863bcd43a9e74
upcxx-guide-2023.9.0.pdf 1735d2a5df888f6348ac55c68a07f5b3