diff --git a/llvm/cmake/modules/LLVMExternalProjectUtils.cmake b/llvm/cmake/modules/LLVMExternalProjectUtils.cmake
--- a/llvm/cmake/modules/LLVMExternalProjectUtils.cmake
+++ b/llvm/cmake/modules/LLVMExternalProjectUtils.cmake
@@ -211,12 +211,6 @@
     list(APPEND compiler_args -DCMAKE_STRIP=${ARG_STRIP_TOOL})
   endif()
 
-  if (ARG_TARGET_TRIPLE)
-    list(APPEND compiler_args -DCMAKE_C_COMPILER_TARGET=${ARG_TARGET_TRIPLE})
-    list(APPEND compiler_args -DCMAKE_CXX_COMPILER_TARGET=${ARG_TARGET_TRIPLE})
-    list(APPEND compiler_args -DCMAKE_ASM_COMPILER_TARGET=${ARG_TARGET_TRIPLE})
-  endif()
-
   add_custom_command(
     OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${name}-clobber-stamp
     DEPENDS ${ARG_DEPENDS}
@@ -238,7 +232,8 @@
   endif()
 
   if(CMAKE_CROSSCOMPILING)
-    set(compiler_args -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
+    set(compiler_args -DCMAKE_ASM_COMPILER=${CMAKE_ASM_COMPILER}
+                      -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
                       -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
                       -DCMAKE_LINKER=${CMAKE_LINKER}
                       -DCMAKE_AR=${CMAKE_AR}
@@ -279,6 +274,12 @@
     set(cmake_args ${ARG_CMAKE_ARGS})
   endif()
 
+  if(ARG_TARGET_TRIPLE)
+    list(APPEND compiler_args -DCMAKE_C_COMPILER_TARGET=${ARG_TARGET_TRIPLE})
+    list(APPEND compiler_args -DCMAKE_CXX_COMPILER_TARGET=${ARG_TARGET_TRIPLE})
+    list(APPEND compiler_args -DCMAKE_ASM_COMPILER_TARGET=${ARG_TARGET_TRIPLE})
+  endif()
+
   ExternalProject_Add(${name}
     DEPENDS ${ARG_DEPENDS} llvm-config
     ${name}-clobber