Thrust 1.9.10 (NVIDIA HPC SDK 20.5)

Thrust 1.9.10 is the release accompanying the NVIDIA HPC SDK 20.5 release. It adds CMake support for compilation with NVC++ and a number of minor bug fixes for NVC++. It also adds CMake find_package support, which replaces the broken 3rd-party legacy FindThrust.cmake script. C++03, C++11, GCC < 5, Clang < 6, and MSVC < 2017 are now deprecated. Starting with the upcoming 1.10.0 release, C++03 support will be dropped entirely. All other deprecated platforms will be dropped in the near future.

Breaking Changes

• #1130: CMake find_package support. This is significant because there is a legacy FindThrust.cmake script authored by a third party in widespread use in the community which has a bug in how it parses Thrust version numbers which will cause it to incorrectly parse 1.9.10. This script only handles the first digit of each part of the Thrust version number correctly: for example, Thrust 17.17.17 would be interpreted as Thrust 1.1.1701717. You can find directions for using the new CMake find_package support and migrating away from the legacy FindThrust.cmake here
• #1082: Thrust now checks that it is compatible with the version of CUB found in your include path, generating an error if it is not. If you are using your own verison of CUB, it may be too old. It is recommended to simply delete your own version of CUB and use the version of CUB that comes with Thrust.
• #1089 C++03 and C++11 are deprecated. Using these dialects will generate a compile-time warning. These warnings can be suppressed by defining THRUST_IGNORE_DEPRECATED_CPP_DIALECT (to suppress C++03 and C++11 deprecation warnings) or THRUST_IGNORE_DEPRECATED_CPP_11 (to suppress C++11 deprecation warnings). Suppression is only a short term solution. We will be dropping support for C++03 in the 1.10.0 release and C++11 in the near future.
• #1089: GCC < 5, Clang < 6, and MSVC < 2017 are deprecated. Using these compilers will generate a compile-time warning. These warnings can be suppressed by defining THRUST_IGNORE_DEPRECATED_COMPILER. Suppression is only a short term solution. We will be dropping support for these compilers in the near future.

New Features

• #1129: Added thrust::detail::single_device_tls_caching_allocator, a convenient way to get an MR caching allocator for device memory, which is used by NVC++.

Other Enhancements

• #1129: Refactored RDC handling in CMake to be a global option and not create two targets for each example and test.

Bug Fixes

• #1129: Fix the legacy thrust::return_temporary_buffer API to support passing a size. This was necessary to enable usage of Thrust caching MR allocators with synchronous Thrust algorithms. This change has allowed NVC++’s C++17 Parallel Algorithms implementation to switch to use Thrust caching MR allocators for device temporary storage, which gives a 2x speedup on large multi-GPU systems such as V100 and A100 DGX where cudaMalloc is very slow.
• #1128: Respect CUDA_API_PER_THREAD_DEFAULT_STREAM. Thanks to Rong Ou for this contribution.
• #1131: Fix the one-policy overload of thrust::async::copy to not copy the policy, resolving use-afer-move issues.
• #1145: When cleaning up type names in unittest::base_class_name, only call std::string::replace if we found the substring we are looking to replace.
• #1139: Don't use cxx::__demangle in NVC++.
• #1102: Don't use thrust::detail::normal_distribution_nvcc for Feta because it uses erfcinv, a non-standard function that Feta doesn't have.