diff --git a/clang/docs/LibASTMatchersReference.html b/clang/docs/LibASTMatchersReference.html
--- a/clang/docs/LibASTMatchersReference.html
+++ b/clang/docs/LibASTMatchersReference.html
@@ -2531,6 +2531,19 @@
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Type.html">Type</a>&gt;</td><td class="name" onclick="toggle('dependentSizedExtVectorType')"><a name="dependentSizedExtVectorType0Anchor">dependentSizedExtVectorType</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1DependentSizedExtVectorType.html">DependentSizedExtVectorType</a>&gt;...</td></tr>
+<tr><td colspan="4" class="doc" id="dependentSizedExtVectorType0"><pre>Matches C++ extended vector type where either the type or size is dependent.
+
+Given
+  template&lt;typename T, int Size&gt;
+  class vector {
+    typedef T __attribute__((ext_vector_type(Size))) type;
+  };
+dependentSizedExtVectorType
+  matches "T __attribute__((ext_vector_type(Size)))"
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Type.html">Type</a>&gt;</td><td class="name" onclick="toggle('elaboratedType0')"><a name="elaboratedType0Anchor">elaboratedType</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1ElaboratedType.html">ElaboratedType</a>&gt;...</td></tr>
 <tr><td colspan="4" class="doc" id="elaboratedType0"><pre>Matches types specified with an elaborated type keyword or with a
 qualified name.
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -228,6 +228,7 @@
 
 AST Matchers
 ------------
+- Add ``dependentSizedExtVectorType``.
 
 clang-format
 ------------
diff --git a/clang/include/clang/ASTMatchers/ASTMatchers.h b/clang/include/clang/ASTMatchers/ASTMatchers.h
--- a/clang/include/clang/ASTMatchers/ASTMatchers.h
+++ b/clang/include/clang/ASTMatchers/ASTMatchers.h
@@ -6938,6 +6938,21 @@
 ///   matches "T data[Size]"
 extern const AstTypeMatcher<DependentSizedArrayType> dependentSizedArrayType;
 
+/// Matches C++ extended vector type where either the type or size is
+/// dependent.
+///
+/// Given
+/// \code
+///   template<typename T, int Size>
+///   class vector {
+///     typedef T __attribute__((ext_vector_type(Size))) type;
+///   };
+/// \endcode
+/// dependentSizedExtVectorType
+///   matches "T __attribute__((ext_vector_type(Size)))"
+extern const AstTypeMatcher<DependentSizedExtVectorType>
+    dependentSizedExtVectorType;
+
 /// Matches C arrays with unspecified size.
 ///
 /// Given
diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -381,7 +381,8 @@
     ExpectedType VisitIncompleteArrayType(const IncompleteArrayType *T);
     ExpectedType VisitVariableArrayType(const VariableArrayType *T);
     ExpectedType VisitDependentSizedArrayType(const DependentSizedArrayType *T);
-    // FIXME: DependentSizedExtVectorType
+    ExpectedType
+    VisitDependentSizedExtVectorType(const DependentSizedExtVectorType *T);
     ExpectedType VisitVectorType(const VectorType *T);
     ExpectedType VisitExtVectorType(const ExtVectorType *T);
     ExpectedType VisitFunctionNoProtoType(const FunctionNoProtoType *T);
@@ -1264,6 +1265,18 @@
       T->getIndexTypeCVRQualifiers(), ToBracketsRange);
 }
 
+ExpectedType ASTNodeImporter::VisitDependentSizedExtVectorType(
+    const DependentSizedExtVectorType *T) {
+  Error Err = Error::success();
+  QualType ToElementType = importChecked(Err, T->getElementType());
+  Expr *ToSizeExpr = importChecked(Err, T->getSizeExpr());
+  SourceLocation ToAttrLoc = importChecked(Err, T->getAttributeLoc());
+  if (Err)
+    return std::move(Err);
+  return Importer.getToContext().getDependentSizedExtVectorType(
+      ToElementType, ToSizeExpr, ToAttrLoc);
+}
+
 ExpectedType ASTNodeImporter::VisitVectorType(const VectorType *T) {
   ExpectedType ToElementTypeOrErr = import(T->getElementType());
   if (!ToElementTypeOrErr)
diff --git a/clang/lib/ASTMatchers/ASTMatchersInternal.cpp b/clang/lib/ASTMatchers/ASTMatchersInternal.cpp
--- a/clang/lib/ASTMatchers/ASTMatchersInternal.cpp
+++ b/clang/lib/ASTMatchers/ASTMatchersInternal.cpp
@@ -1046,6 +1046,7 @@
 const AstTypeMatcher<DeducedTemplateSpecializationType>
     deducedTemplateSpecializationType;
 const AstTypeMatcher<DependentSizedArrayType> dependentSizedArrayType;
+const AstTypeMatcher<DependentSizedExtVectorType> dependentSizedExtVectorType;
 const AstTypeMatcher<IncompleteArrayType> incompleteArrayType;
 const AstTypeMatcher<VariableArrayType> variableArrayType;
 const AstTypeMatcher<AtomicType> atomicType;
diff --git a/clang/lib/ASTMatchers/Dynamic/Registry.cpp b/clang/lib/ASTMatchers/Dynamic/Registry.cpp
--- a/clang/lib/ASTMatchers/Dynamic/Registry.cpp
+++ b/clang/lib/ASTMatchers/Dynamic/Registry.cpp
@@ -227,6 +227,7 @@
   REGISTER_MATCHER(defaultStmt);
   REGISTER_MATCHER(dependentCoawaitExpr);
   REGISTER_MATCHER(dependentSizedArrayType);
+  REGISTER_MATCHER(dependentSizedExtVectorType);
   REGISTER_MATCHER(designatedInitExpr);
   REGISTER_MATCHER(designatorCountIs);
   REGISTER_MATCHER(doStmt);
diff --git a/clang/unittests/AST/ASTImporterFixtures.h b/clang/unittests/AST/ASTImporterFixtures.h
--- a/clang/unittests/AST/ASTImporterFixtures.h
+++ b/clang/unittests/AST/ASTImporterFixtures.h
@@ -260,6 +260,8 @@
                          FromAST->getFileManager(), false);
 
     auto FoundNodes = match(SearchMatcher, FromCtx);
+    if (FoundNodes.empty())
+      return testing::AssertionFailure() << "No node was found!";
     if (FoundNodes.size() != 1)
       return testing::AssertionFailure()
              << "Multiple potential nodes were found!";
diff --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp
--- a/clang/unittests/AST/ASTImporterTest.cpp
+++ b/clang/unittests/AST/ASTImporterTest.cpp
@@ -1044,6 +1044,17 @@
                  has(fieldDecl(hasType(dependentSizedArrayType())))))));
 }
 
+TEST_P(ImportExpr, DependentSizedExtVectorType) {
+  MatchVerifier<Decl> Verifier;
+  testImport("template<typename T, int Size>"
+             "class declToImport {"
+             "  typedef T __attribute__((ext_vector_type(Size))) type;"
+             "};",
+             Lang_CXX03, "", Lang_CXX03, Verifier,
+             classTemplateDecl(has(cxxRecordDecl(
+                 has(typedefDecl(hasType(dependentSizedExtVectorType())))))));
+}
+
 TEST_P(ASTImporterOptionSpecificTestBase, ImportUsingPackDecl) {
   Decl *FromTU = getTuDecl(
       "struct A { int operator()() { return 1; } };"
diff --git a/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp b/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
--- a/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
+++ b/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
@@ -1560,6 +1560,20 @@
                  dependentSizedArrayType()));
 }
 
+TEST_P(ASTMatchersTest, DependentSizedExtVectorType) {
+  if (!GetParam().isCXX()) {
+    return;
+  }
+  EXPECT_TRUE(matches("template<typename T, int Size>"
+                      "class vector {"
+                      "  typedef T __attribute__((ext_vector_type(Size))) type;"
+                      "};",
+                      dependentSizedExtVectorType()));
+  EXPECT_TRUE(
+      notMatches("int a[42]; int b[] = { 2, 3 }; void f() { int c[b[0]]; }",
+                 dependentSizedExtVectorType()));
+}
+
 TEST_P(ASTMatchersTest, IncompleteArrayType) {
   EXPECT_TRUE(matches("int a[] = { 2, 3 };", incompleteArrayType()));
   EXPECT_TRUE(matches("void f(int a[]) {}", incompleteArrayType()));