Index: include/llvm/Target/Target.td
===================================================================
--- include/llvm/Target/Target.td
+++ include/llvm/Target/Target.td
@@ -1006,6 +1006,15 @@
 
   // Predicates - Predicates that must be true for this to match.
   list<Predicate> Predicates = [];
+
+	// If the instruction specified in Result has defined an AsmMatchConverter
+  // then setting this to 1 will cause the alias to use the AsmMatchConverter
+  // function when converting the OperandVector into an MCInst instead of the
+  // function that is generated by the dag Result.
+  // Setting this to 0 will cause the alias to ignore the Result instruction's
+  // defined AsmMatchConverter and instead use the function generated by the
+  // dag Result.
+  bit UseInstAsmMatchConverter = 1;
 }
 
 //===----------------------------------------------------------------------===//
Index: utils/TableGen/AsmMatcherEmitter.cpp
===================================================================
--- utils/TableGen/AsmMatcherEmitter.cpp
+++ utils/TableGen/AsmMatcherEmitter.cpp
@@ -438,12 +438,21 @@
   /// If this instruction is deprecated in some form.
   bool HasDeprecation;
 
+  /// If this is an alias, this is use to determine whether or not to using
+  /// the conversion function defined by the instruction's AsmMatchConverter
+  /// or to use the function generated by the alias.
+  bool UseInstAsmMatchConverter;
+
   MatchableInfo(const CodeGenInstruction &CGI)
-    : AsmVariantID(0), AsmString(CGI.AsmString), TheDef(CGI.TheDef), DefRec(&CGI) {
+    : AsmVariantID(0), AsmString(CGI.AsmString), TheDef(CGI.TheDef), DefRec(&CGI),
+      UseInstAsmMatchConverter(true) {
   }
 
   MatchableInfo(std::unique_ptr<const CodeGenInstAlias> Alias)
-    : AsmVariantID(0), AsmString(Alias->AsmString), TheDef(Alias->TheDef), DefRec(Alias.release()) {
+    : AsmVariantID(0), AsmString(Alias->AsmString), TheDef(Alias->TheDef),
+      DefRec(Alias.release()),
+      UseInstAsmMatchConverter(
+        TheDef->getValueAsBit("UseInstAsmMatchConverter")) {
   }
 
   ~MatchableInfo() {
@@ -1749,7 +1758,7 @@
     // Check if we have a custom match function.
     std::string AsmMatchConverter =
       II->getResultInst()->TheDef->getValueAsString("AsmMatchConverter");
-    if (!AsmMatchConverter.empty()) {
+    if (!AsmMatchConverter.empty() && II->UseInstAsmMatchConverter) {
       std::string Signature = "ConvertCustom_" + AsmMatchConverter;
       II->ConversionFnKind = Signature;