select the architecture based on nvcc result

  * cache the result
  * DRY
  * brush up based on review

cmake/OpenCVDetectCUDA.cmake

@@ -53,6 +53,12 @@ if(CUDA_FOUND)
   message(STATUS "CUDA detected: " ${CUDA_VERSION})
 
   set(_generations "Fermi" "Kepler" "Maxwell" "Pascal" "Volta" "Turing")
+  set(_arch_fermi   "2.0")
+  set(_arch_kepler  "3.0;3.5;3.7")
+  set(_arch_maxwell "5.0;5.2")
+  set(_arch_pascal  "6.0;6.1")
+  set(_arch_volta   "7.0")
+  set(_arch_turing  "7.5")
   if(NOT CMAKE_CROSSCOMPILING)
     list(APPEND _generations "Auto")
   endif()
@@ -70,29 +76,57 @@ if(CUDA_FOUND)
     unset(CUDA_ARCH_PTX CACHE)
   endif()
 
+  macro(ocv_filter_available_architecture result_list)
+    if(DEFINED CUDA_SUPPORTED_CC)
+      set(${result_list} "${CUDA_SUPPORTED_CC}")
+    else()
+      set(CC_LIST ${ARGN})
+      foreach(target_arch ${CC_LIST})
+        string(REPLACE "." "" target_arch_short ${target_arch})
+        set(NVCC_OPTION "-gencode;arch=compute_${target_arch_short},code=sm_${target_arch_short}")
+        execute_process( COMMAND "${CUDA_NVCC_EXECUTABLE}" ${NVCC_OPTION} "${OpenCV_SOURCE_DIR}/cmake/checks/OpenCVDetectCudaArch.cu"
+                         WORKING_DIRECTORY "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/"
+                         RESULT_VARIABLE _nvcc_res OUTPUT_VARIABLE _nvcc_out
+                         ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
+        if(_nvcc_res EQUAL 0)
+          set(${result_list} "${${result_list}} ${target_arch}")
+        endif()
+      endforeach()
+      string(STRIP ${${result_list}} ${result_list})
+      set(CUDA_SUPPORTED_CC ${${result_list}} CACHE INTERNAL "List of supported compute capability")
+    endif()
+  endmacro()
+
+  macro(ocv_detect_native_cuda_arch status output)
+    execute_process( COMMAND "${CUDA_NVCC_EXECUTABLE}" ${CUDA_NVCC_FLAGS} "${OpenCV_SOURCE_DIR}/cmake/checks/OpenCVDetectCudaArch.cu" "--run"
+                     WORKING_DIRECTORY "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/"
+                     RESULT_VARIABLE ${status} OUTPUT_VARIABLE ${output}
+                     ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
+  endmacro()
+
+  macro(ocv_wipeout_deprecated _arch_bin_list)
+    string(REPLACE "2.1" "2.1(2.0)" ${_arch_bin_list} ${${_arch_bin_list}})
+  endmacro()
+
   set(__cuda_arch_ptx "")
   if(CUDA_GENERATION STREQUAL "Fermi")
-    set(__cuda_arch_bin "2.0")
+    set(__cuda_arch_bin ${_arch_fermi})
   elseif(CUDA_GENERATION STREQUAL "Kepler")
-    set(__cuda_arch_bin "3.0 3.5 3.7")
+    set(__cuda_arch_bin ${_arch_kepler})
   elseif(CUDA_GENERATION STREQUAL "Maxwell")
-    set(__cuda_arch_bin "5.0 5.2")
+    set(__cuda_arch_bin ${_arch_maxwell})
   elseif(CUDA_GENERATION STREQUAL "Pascal")
-    set(__cuda_arch_bin "6.0 6.1")
+    set(__cuda_arch_bin ${_arch_pascal})
   elseif(CUDA_GENERATION STREQUAL "Volta")
-    set(__cuda_arch_bin "7.0")
+    set(__cuda_arch_bin ${_arch_volta})
   elseif(CUDA_GENERATION STREQUAL "Turing")
-    set(__cuda_arch_bin "7.5")
+    set(__cuda_arch_bin ${_arch_turing})
   elseif(CUDA_GENERATION STREQUAL "Auto")
-    execute_process( COMMAND "${CUDA_NVCC_EXECUTABLE}" ${CUDA_NVCC_FLAGS} "${OpenCV_SOURCE_DIR}/cmake/checks/OpenCVDetectCudaArch.cu" "--run"
-                     WORKING_DIRECTORY "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/"
-                     RESULT_VARIABLE _nvcc_res OUTPUT_VARIABLE _nvcc_out
-                     ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
+    ocv_detect_native_cuda_arch(_nvcc_res _nvcc_out)
     if(NOT _nvcc_res EQUAL 0)
       message(STATUS "Automatic detection of CUDA generation failed. Going to build for all known architectures.")
     else()
-      set(__cuda_arch_bin "${_nvcc_out}")
-      string(REPLACE "2.1" "2.1(2.0)" __cuda_arch_bin "${__cuda_arch_bin}")
+      string(REGEX MATCHALL "[0-9]+\\.[0-9]" __cuda_arch_bin "${_nvcc_out}")
     endif()
   endif()
 
@@ -101,28 +135,26 @@ if(CUDA_FOUND)
       set(__cuda_arch_bin "3.2")
       set(__cuda_arch_ptx "")
     elseif(AARCH64)
-      execute_process( COMMAND "${CUDA_NVCC_EXECUTABLE}" ${CUDA_NVCC_FLAGS} "${OpenCV_SOURCE_DIR}/cmake/checks/OpenCVDetectCudaArch.cu" "--run"
-                       WORKING_DIRECTORY "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/"
-                       RESULT_VARIABLE _nvcc_res OUTPUT_VARIABLE _nvcc_out
-                       ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
+      ocv_detect_native_cuda_arch(_nvcc_res _nvcc_out)
       if(NOT _nvcc_res EQUAL 0)
         message(STATUS "Automatic detection of CUDA generation failed. Going to build for all known architectures.")
         set(__cuda_arch_bin "5.3 6.2 7.2")
       else()
         set(__cuda_arch_bin "${_nvcc_out}")
-        string(REPLACE "2.1" "2.1(2.0)" __cuda_arch_bin "${__cuda_arch_bin}")
       endif()
       set(__cuda_arch_ptx "")
     else()
-      if(CUDA_VERSION VERSION_LESS "9.0")
-        set(__cuda_arch_bin "2.0 3.0 3.5 3.7 5.0 5.2 6.0 6.1")
-      elseif(CUDA_VERSION VERSION_LESS "10.0")
-        set(__cuda_arch_bin "3.0 3.5 3.7 5.0 5.2 6.0 6.1 7.0")
-      else()
-        set(__cuda_arch_bin "3.0 3.5 3.7 5.0 5.2 6.0 6.1 7.0 7.5")
-      endif()
+      ocv_filter_available_architecture(__cuda_arch_bin
+          ${_arch_fermi}
+          ${_arch_kepler}
+          ${_arch_maxwell}
+          ${_arch_pascal}
+          ${_arch_volta}
+          ${_arch_turing}
+      )
     endif()
   endif()
+  ocv_wipeout_deprecated(__cuda_arch_bin)
 
   set(CUDA_ARCH_BIN ${__cuda_arch_bin} CACHE STRING "Specify 'real' GPU architectures to build binaries for, BIN(PTX) format is supported")
   set(CUDA_ARCH_PTX ${__cuda_arch_ptx} CACHE STRING "Specify 'virtual' PTX architectures to build PTX intermediate code for")