Index: cmake/modules/GetHostTriple.cmake
===================================================================
--- cmake/modules/GetHostTriple.cmake
+++ cmake/modules/GetHostTriple.cmake
@@ -2,6 +2,10 @@
 # Invokes config.guess
 
 function( get_host_triple var )
+  if( LLVM_HOST_TRIPLE )
+	set( value ${LLVM_HOST_TRIPLE} )
+	return()
+  endif()
   if( MSVC )
     if( CMAKE_CL_64 )
       set( value "x86_64-pc-win32" )