diff --git a/llvm/utils/TableGen/DAGISelMatcher.cpp b/llvm/utils/TableGen/DAGISelMatcher.cpp
index 0c45ff1353ce..b2d819cae9ea 100644
--- a/llvm/utils/TableGen/DAGISelMatcher.cpp
+++ b/llvm/utils/TableGen/DAGISelMatcher.cpp
@@ -412,3 +412,16 @@ bool CheckValueTypeMatcher::isContradictoryImpl(const Matcher *M) const {
   return false;
 }
 
+bool CheckImmAllOnesVMatcher::isContradictoryImpl(const Matcher *M) const {
+  // AllZeros is contradictory.
+  if (const auto *CIAZVM = dyn_cast<CheckImmAllZerosVMatcher>(M))
+    return true;
+  return false;
+}
+
+bool CheckImmAllZerosVMatcher::isContradictoryImpl(const Matcher *M) const {
+  // AllOnes is contradictory.
+  if (const auto *CIAOVM = dyn_cast<CheckImmAllOnesVMatcher>(M))
+    return true;
+  return false;
+}
diff --git a/llvm/utils/TableGen/DAGISelMatcher.h b/llvm/utils/TableGen/DAGISelMatcher.h
index 24932e64cb47..0a782e84a372 100644
--- a/llvm/utils/TableGen/DAGISelMatcher.h
+++ b/llvm/utils/TableGen/DAGISelMatcher.h
@@ -770,6 +770,7 @@ public:
 private:
   void printImpl(raw_ostream &OS, unsigned indent) const override;
   bool isEqualImpl(const Matcher *M) const override { return true; }
+  bool isContradictoryImpl(const Matcher *M) const override;
 };
 
 /// CheckImmAllZerosVMatcher - This check if the current node is an build vector
@@ -785,6 +786,7 @@ public:
 private:
   void printImpl(raw_ostream &OS, unsigned indent) const override;
   bool isEqualImpl(const Matcher *M) const override { return true; }
+  bool isContradictoryImpl(const Matcher *M) const override;
 };
 
 /// CheckFoldableChainNodeMatcher - This checks to see if the current node