Index: lib/Target/X86/X86ISelLowering.cpp
===================================================================
--- lib/Target/X86/X86ISelLowering.cpp
+++ lib/Target/X86/X86ISelLowering.cpp
@@ -2991,11 +2991,14 @@
       "Var args not supported with calling conv' regcall, fastcc, ghc or hipe");
 
   if (CallConv == CallingConv::X86_INTR) {
-    bool isLegal = Ins.size() == 1 ||
-                   (Ins.size() == 2 && ((Is64Bit && Ins[1].VT == MVT::i64) ||
-                                        (!Is64Bit && Ins[1].VT == MVT::i32)));
-    if (!isLegal)
+    bool isArgnLegal = Ins.size() == 1 || Ins.size() == 2;
+    if (!isArgnLegal)
       report_fatal_error("X86 interrupts may take one or two arguments");
+    bool isArg2Legal = (Is64Bit && Ins[1].VT == MVT::i64) ||
+                       (!Is64Bit && Ins[1].VT == MVT::i32);
+	if (!isArg2Legal)
+	  report_fatal_error("X86 interrupts' second argument must be a "
+			             "machine-sized word");
   }
 
   // Assign locations to all of the incoming arguments.