Remove hard coding of cuda_architectures (#52)

* Remove hard coding of cmake_cuda_architectures.

* Add EXAWIND_CUDA_ARCH variable.

CMakeLists.txt

@@ -3,7 +3,6 @@ cmake_minimum_required(VERSION 3.14.0 FATAL_ERROR)
 project(exawind CXX C)
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON CACHE INTERNAL "")
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake")
-include(exawind-utils)
 
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_EXTENSIONS OFF)
@@ -18,6 +17,7 @@ option(EXAWIND_ENABLE_UMPIRE "Enable Umpire GPU memory pools" OFF)
 if(EXAWIND_ENABLE_CUDA)
   enable_language(CUDA)
   find_package(CUDAToolkit REQUIRED)
+  set(EXAWIND_CUDA_ARCH "70" CACHE STRING "CUDA architecture (Use 'Auto' for automatic detection)")
 endif()
 
 if(EXAWIND_ENABLE_ROCM)
@@ -70,6 +70,7 @@ add_executable(${EXAWIND_EXE_NAME})
 add_subdirectory(app/exawind)
 
 if(EXAWIND_ENABLE_CUDA)
+  include(exawind-utils)
   set(ewtargets "${EXAWIND_LIB_NAME};${EXAWIND_EXE_NAME}")
   foreach(tgt IN LISTS ewtargets)
     set_cuda_build_properties(${tgt})

cmake/exawind-utils.cmake

@@ -3,7 +3,7 @@ function(set_cuda_build_properties target)
   list(FILTER _tgt_src INCLUDE REGEX "\\.cpp")
   set_source_files_properties(${_tgt_src} PROPERTIES LANGUAGE CUDA)
   set_target_properties(${target} PROPERTIES CUDA_SEPARABLE_COMPILATION ON)
-  set_target_properties(${target} PROPERTIES CUDA_ARCHITECTURES "70")
+  set_target_properties(${target} PROPERTIES CUDA_ARCHITECTURES "${EXAWIND_CUDA_ARCH")
   set_target_properties(${target} PROPERTIES CUDA_RESOLVE_DEVICE_SYMBOLS ON)
   #set_target_properties(${target} PROPERTIES LINKER_LANGUAGE CUDA)
 endfunction(set_cuda_build_properties)