Version 22.06.0 (June 29, 2022)

• Regent
  • Support for cross-products in index launches, as well as multi-level projection functors.
  • Support for HIP on AMD GPUs has been added. All tasks marked with __demand(__cuda) are automatically eligible. Note that the name of the annotation may change in the future to something more general, but for now no change is being made. Some CUDA flags have migrated to more general names. See below.
  • The flag -fcuda 1 is deprecated. Use -fgpu cuda instead.
  • The flag -fcuda-offline is deprecated. Use -fgpu-offline instead.
  • The flag -fcuda-arch is deprecated. Use -fgpu-arch instead.
  • Enable HIP support with -fgpu hip and use the -fgpu-offline and -fgpu-arch flags as necessary/appropriate.
  • Support for new flag -ffast-math 1 which enables fast-math optimizations on CPU and GPU. By default, CPU code has this disabled, and GPU code uses only the contract flag in LLVM to generate FMA instructions. For compute-intensive applications, additional performance can sometimes be unlocked by enabling the full suite of optimizations with -ffast-math 1, at the cost of numerical accuracy.
  • Performance improvements for CUDA allow recent LLVM versions (e.g., 13) to match or exceed the performance of LLVM 3.8. Previously, performance regressions made LLVM 3.8 the most performant version for use with CUDA. The recommended LLVM version moving forward is 13, and setup_env.py has been updated to set this on all platforms.
  • The versions of GASNet and Terra are now pinned by default in setup_env.py. You can choose versions explicitly with GASNET_VERSION (as before, though the previous default was unpinned) and --terra-branch, respectively.
• Realm
  • Allow use of system OpenMP runtime (instead of Realm-provided one) with -DLegion_OpenMP_SYSTEM_RUNTIME=ON. This allows inter-operation with libraries that have already been linked to the system runtime, but limits each process to a single OMP processor.