[BUG]: atomic_storage_test fails in Release builds on CUDA < 13.1

[sleeepyjack]

Symptom

tests/static_set/atomic_storage_test spuriously fails in Release builds on CUDA < 13.1, missing one or more inserts:

tests/static_set/atomic_storage_test.cu:74: FAILED:
REQUIRE( count == num_keys )
with expansion:
99999 (0x1869f) == 100000 (0x186a0)

Reproduces in CI on CUDA 12.0. Uses cuco::pair<uint32_t, int32_t> (8 B), hitting the packed_cas path.

Root cause

The test was added in #706 as a minimal reproducer for the CCCL __cuda_is_local / isspacep.local miscompile (originally rapidsai/cudf#18584, rapidsai/cudf#18587, NVIDIA/spark-rapids#12586). NVIDIA/cccl#4586 introduced _CCCL_ATOMIC_UNSAFE_AUTOMATIC_STORAGE to bypass the broken check, with this auto-define in libcudacxx/include/cuda/std/__internal/atomic.h:

// Enable bypassing automatic storage checks ... when using CTK 12.2 and below and if NDEBUG is defined.
#ifndef _CCCL_ATOMIC_UNSAFE_AUTOMATIC_STORAGE
#  if _CCCL_CUDACC_BELOW(13, 1) && !defined(NDEBUG)
#    define _CCCL_ATOMIC_UNSAFE_AUTOMATIC_STORAGE
#  endif
#endif

With the current code the bypass fires only in debug builds. Cuco CI runs CMAKE_BUILD_TYPE=Release, NDEBUG is defined, thus the bug shows up.

Fix

Define the macro for cuco regardless of build mode, but gate it on CTK so it auto-disappears once the upstream nvcc bug is fixed in 13.1+. Either at the header level in include/cuco/detail/__config:

#if !defined(_CCCL_ATOMIC_UNSAFE_AUTOMATIC_STORAGE)             \
    && defined(__CUDACC_VER_MAJOR__)                            \
    && ((__CUDACC_VER_MAJOR__ < 13)                             \
        || (__CUDACC_VER_MAJOR__ == 13 && __CUDACC_VER_MINOR__ < 1))
#  define _CCCL_ATOMIC_UNSAFE_AUTOMATIC_STORAGE
#endif

Reproduction

./ci/build.sh -tests
ctest -R atomic_storage_test --output-on-failure  # CTK < 13.1

Related

• Add atomic storage test #706 (added the test)
• Always bypass automatic atomic storage checks to prevent potential compiler issues cccl#4586, [Backport branch/2.8.x] Always bypass automatic atomic storage checks to prevent potential compiler issues cccl#4616 (CCCL fix + 2.8.x backport)
• Get newer CCCL 2.8 with fix for atomics. rapidsai/rapids-cmake#840 (rolled into rapids)