Use CMAKE_SYSTEM_PROCESSOR to determine if NS test can be run

 - Prevent having to explicitly run `uname` CMAKE_SYSTEM_PROCESSOR holds
   the output of `uname -p` which will be x86_64 on all x86_64 Linux
   machines, and another value on incompatible machines line OS X, arm,
   etc.

- Since this is a CMake variable no scoping/inheritence etc. issues, or
  concerns about conditional definition etc.

Author: zbeekman

CMakeLists.txt

@@ -169,15 +169,10 @@ if(opencoarrays_aware_compiler)
   add_mpi_test(hello_multiverse 2 ${tests_root}/integration/coarrayHelloWorld/hello_multiverse)
   add_mpi_test(coarray_burgers_pde 2 ${tests_root}/integration/pde_solvers/coarrayBurgers/coarray_burgers_pde)
   add_mpi_test(co_heat 2 ${tests_root}/integration/pde_solvers/coarrayHeatSimplified/co_heat)
-
-  execute_process (COMMAND uname -m
-                   OUTPUT_VARIABLE MACHINE_TYPE)
-  if ("${CMAKE_SYSTEM_NAME}" MATCHES "Linux" )
-    if ("${MACHINE_TYPE}" MATCHES "x86_64")
-      if ( NOT (DEFINED ENV{TRAVIS}))
-	add_mpi_test(coarray_navier_stokes 2 ${tests_root}/integration/pde_solvers/navier-stokes/coarray_navier_stokes)
-	set_property(TEST coarray_navier_stokes PROPERTY PASS_REGULAR_EXPRESSION "Test passed.")
-      endif()
+  if ( ("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "x86_64") AND ("${CMAKE_SYSTEM_NAME}" MATCHES "Linux") )
+    if ( NOT (DEFINED ENV{TRAVIS}))
+      add_mpi_test(coarray_navier_stokes 2 ${tests_root}/integration/pde_solvers/navier-stokes/coarray_navier_stokes)
+      set_property(TEST coarray_navier_stokes PROPERTY PASS_REGULAR_EXPRESSION "Test passed.")
     endif()
   endif()
 else()

src/tests/integration/pde_solvers/navier-stokes/CMakeLists.txt

@@ -1,10 +1,7 @@
-if ("${CMAKE_SYSTEM_NAME}" MATCHES "Linux")
-  execute_process (COMMAND uname -m
-                   OUTPUT_VARIABLE MACHINE_TYPE)
-  # checking whether the machine is of type 64-bit before proceeding further
-  if ("${MACHINE_TYPE}" MATCHES "x86_64")
-    # Default to older SSE-instruction-based FFT library
-    if (NOT (DEFINED ENV{TRAVIS}))
+# checking whether the machine is of type 64-bit before proceeding further
+if ( ("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "x86_64") AND ("${CMAKE_SYSTEM_NAME}" MATCHES "LINUX") )
+  # Default to older SSE-instruction-based FFT library
+  if (NOT (DEFINED ENV{TRAVIS}))
     if (LEGACY_ARCHITECTURE OR (NOT DEFINED(LEGACY_ARCHITECTURE)))
       set(fft_library ${CMAKE_CURRENT_SOURCE_DIR}/libfft_sse.a )
     else()
@@ -17,7 +14,6 @@ if ("${CMAKE_SYSTEM_NAME}" MATCHES "Linux")
     )
     target_link_libraries(coarray_navier_stokes OpenCoarrays ${fft_library})
   endif()
-  endif()
 else()
   # Skip Navier-Stokes build until an appropriate FFT has been found.
 endif()