Index: Bitcode/Regression/CMakeLists.txt
===================================================================
--- Bitcode/Regression/CMakeLists.txt
+++ Bitcode/Regression/CMakeLists.txt
@@ -1,3 +1,4 @@
+set(NO_REFERENCE_OUTPUT true)
 if(ARCH STREQUAL "x86")
   add_subdirectory(vector_widen)
 endif()
Index: Bitcode/simd_ops/CMakeLists.txt
===================================================================
--- Bitcode/simd_ops/CMakeLists.txt
+++ Bitcode/simd_ops/CMakeLists.txt
@@ -1,3 +1,4 @@
+set(NO_REFERENCE_OUTPUT true)
 file(GLOB uosources ${CMAKE_CURRENT_SOURCE_DIR}/${ARCH}_tests/*.bc)
 SET_SOURCE_FILES_PROPERTIES(${uosources} PROPERTIES LANGUAGE CXX)
 file(GLOB scalar_sources ${CMAKE_CURRENT_SOURCE_DIR}/${ARCH}_scalar_tests/*.bc)
Index: cmake/modules/SingleMultiSource.cmake
===================================================================
--- cmake/modules/SingleMultiSource.cmake
+++ cmake/modules/SingleMultiSource.cmake
@@ -90,16 +90,18 @@
     endif()
 
     # Pick the best reference output based on "programname.reference_output".
-    if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${name}.reference_output.${ENDIAN}-endian.${KEY})
-      set(REFERENCE_OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/${name}.reference_output.${ENDIAN}-endian.${KEY})
-    elseif(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${name}.reference_output.${KEY})
-      set(REFERENCE_OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/${name}.reference_output.${KEY})
-    elseif(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${name}.reference_output.${ENDIAN}-endian)
-      set(REFERENCE_OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/${name}.reference_output.${ENDIAN}-endian)
-    elseif(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${name}.reference_output)
-      set(REFERENCE_OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/${name}.reference_output)
-    else()
-      message("-- No reference output found for test ${name}")
+    if(NOT DEFINED NO_REFERENCE_OUTPUT)
+      if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${name}.reference_output.${ENDIAN}-endian.${KEY})
+        set(REFERENCE_OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/${name}.reference_output.${ENDIAN}-endian.${KEY})
+      elseif(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${name}.reference_output.${KEY})
+        set(REFERENCE_OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/${name}.reference_output.${KEY})
+      elseif(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${name}.reference_output.${ENDIAN}-endian)
+        set(REFERENCE_OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/${name}.reference_output.${ENDIAN}-endian)
+      elseif(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${name}.reference_output)
+        set(REFERENCE_OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/${name}.reference_output)
+      else()
+        message("-- No reference output found for test ${name}")
+      endif()
     endif()
 
     set(DIFFPROG ${CMAKE_BINARY_DIR}/tools/fpcmp)