Determining which gencode (compute_, arch_) values I need for nvcc - within CMake

Question

I\'m using CMake as a build system for my code, which involves CUDA. I was thinking of automating the task of deciding which compute_XX and arch_XX

Answer 1

You can use the cuda_select_nvcc_arch_flags() macro in the FindCUDA module for this without any additional scripts when using CMake 3.7 or newer.

include(FindCUDA)
set(CUDA_ARCH_LIST Auto CACHE STRING
    "List of CUDA architectures (e.g. Pascal, Volta, etc) or \
compute capability versions (6.1, 7.0, etc) to generate code for. \
Set to Auto for automatic detection (default)."
)
cuda_select_nvcc_arch_flags(CUDA_ARCH_FLAGS ${CUDA_ARCH_LIST})
list(APPEND CUDA_NVCC_FLAGS ${CUDA_ARCH_FLAGS})

The above sets CUDA_ARCH_FLAGS to -gencode arch=compute_61,code=sm_61 on my machine, for example. The CUDA_ARCH_LIST cache variable can be configured by the user to generate code for specific compute capabilites instead of automatic detection.

Note: the FindCUDA module has been deprecated since CMake 3.10. However, no equivalent alternative to the cuda_select_nvcc_arch_flags() macro appears to be provided yet in the latest CMake release (v3.14). See this relevant issue at the CMake issue tracker for further details.