updated cuda.cmake to handle stupid unresolved extern function errors when compiling with gencode

cmake/cuda.cmake

@@ -14,10 +14,14 @@ if(ENABLE_CUDA)
   set(CUDA_PROPAGATE_HOST_FLAGS OFF)
 
   # Pass options to NVCC ( -ccbin /path  --compiler-options -lfftw3f --compiler-options -lm --verbose)
-  list(APPEND CUDA_NVCC_FLAGS -DENABLE_CUDA --std c++11)
+  list(APPEND CUDA_NVCC_FLAGS -DENABLE_CUDA --std c++11 -Wno-deprecated-gpu-targets)
   list(APPEND CUDA_NVCC_FLAGS_DEBUG --debug; --device-debug; --generate-line-info -Xcompiler "-Werror")
   #list(APPEND CUDA_NVCC_FLAGS -arch compute_35) # minumum compute level (Sps restriction)
-  list(APPEND CUDA_NVCC_FLAGS -gencode arch=compute_61,code=sm_61) # GTX1080Ti
+  string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
+  if(NOT uppercase_CMAKE_BUILD_TYPE MATCHES "DEBUG")
+        message("Enabling device specific compilation as not in DEBUG mode")
+        list(APPEND CUDA_NVCC_FLAGS -gencode arch=compute_61,code=sm_61) # GTX1080Ti
+  endif(NOT uppercase_CMAKE_BUILD_TYPE MATCHES "DEBUG")
   #list(APPEND CUDA_NVCC_FLAGS -gencode arch=compute_52,code=sm_52) # TitanX
   #list(APPEND CUDA_NVCC_FLAGS -gencode arch=compute_50,code=sm_50) # Maxwell
   #list(APPEND CUDA_NVCC_FLAGS -gencode arch=compute_37,code=sm_37) # K80