Wild and passionate uncontrolled goose chases are amusing to watch, but not

very helpful.  Let bugpoint favor being helpful instead of determined.

llvm-svn: 11652

llvm/tools/bugpoint/CodeGeneratorBug.cpp

@@ -348,6 +348,13 @@ static void DisambiguateGlobalSymbols(Module *M) {
 
 
 bool BugDriver::debugCodeGenerator() {
+  if ((void*)cbe == (void*)Interpreter) {
+    std::cout << "*** The C backend cannot match the reference diff, but it is "
+              << "used as the 'known good'\n     code generator, so I can't deb"
+              << "ug it.  Perhaps you have a front-end problem?\n";
+    return true;
+  }
+
   // See if we can pin down which functions are being miscompiled...
   // First, build a list of all of the non-external functions in the program.
   std::vector<Function*> MisCodegenFunctions;