diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -7658,24 +7658,8 @@
     return;
   }
 
-  Expr *SizeExpr;
-  // Special case where the argument is a template id.
-  if (Attr.isArgIdent(0)) {
-    CXXScopeSpec SS;
-    SourceLocation TemplateKWLoc;
-    UnqualifiedId Id;
-    Id.setIdentifier(Attr.getArgAsIdent(0)->Ident, Attr.getLoc());
-
-    ExprResult Size = S.ActOnIdExpression(S.getCurScope(), SS, TemplateKWLoc,
-                                          Id, /*HasTrailingLParen=*/false,
-                                          /*IsAddressOfOperand=*/false);
-
-    if (Size.isInvalid())
-      return;
-    SizeExpr = Size.get();
-  } else {
-    SizeExpr = Attr.getArgAsExpr(0);
-  }
+  assert(Attr.isArgExpr(0) && "Argument to should be an expression");
+  Expr *SizeExpr = Attr.getArgAsExpr(0);
 
   QualType T = S.BuildVectorType(CurType, SizeExpr, Attr.getLoc());
   if (!T.isNull())
@@ -7695,25 +7679,8 @@
     return;
   }
 
-  Expr *sizeExpr;
-
-  // Special case where the argument is a template id.
-  if (Attr.isArgIdent(0)) {
-    CXXScopeSpec SS;
-    SourceLocation TemplateKWLoc;
-    UnqualifiedId id;
-    id.setIdentifier(Attr.getArgAsIdent(0)->Ident, Attr.getLoc());
-
-    ExprResult Size = S.ActOnIdExpression(S.getCurScope(), SS, TemplateKWLoc,
-                                          id, /*HasTrailingLParen=*/false,
-                                          /*IsAddressOfOperand=*/false);
-    if (Size.isInvalid())
-      return;
-
-    sizeExpr = Size.get();
-  } else {
-    sizeExpr = Attr.getArgAsExpr(0);
-  }
+  assert(Attr.isArgExpr(0) && "Argument to should be an expression");
+  Expr *sizeExpr = Attr.getArgAsExpr(0);
 
   // Create the vector type.
   QualType T = S.BuildExtVectorType(CurType, sizeExpr, Attr.getLoc());
@@ -7991,44 +7958,13 @@
   Expr *RowsExpr = nullptr;
   Expr *ColsExpr = nullptr;
 
-  // TODO: Refactor parameter extraction into separate function
   // Get the number of rows
-  if (Attr.isArgIdent(0)) {
-    CXXScopeSpec SS;
-    SourceLocation TemplateKeywordLoc;
-    UnqualifiedId id;
-    id.setIdentifier(Attr.getArgAsIdent(0)->Ident, Attr.getLoc());
-    ExprResult Rows = S.ActOnIdExpression(S.getCurScope(), SS,
-                                          TemplateKeywordLoc, id, false, false);
-
-    if (Rows.isInvalid())
-      // TODO: maybe a good error message would be nice here
-      return;
-    RowsExpr = Rows.get();
-  } else {
-    assert(Attr.isArgExpr(0) &&
-           "Argument to should either be an identity or expression");
-    RowsExpr = Attr.getArgAsExpr(0);
-  }
+  assert(Attr.isArgExpr(0) && "Argument should be an expression");
+  RowsExpr = Attr.getArgAsExpr(0);
 
   // Get the number of columns
-  if (Attr.isArgIdent(1)) {
-    CXXScopeSpec SS;
-    SourceLocation TemplateKeywordLoc;
-    UnqualifiedId id;
-    id.setIdentifier(Attr.getArgAsIdent(1)->Ident, Attr.getLoc());
-    ExprResult Columns = S.ActOnIdExpression(
-        S.getCurScope(), SS, TemplateKeywordLoc, id, false, false);
-
-    if (Columns.isInvalid())
-      // TODO: a good error message would be nice here
-      return;
-    RowsExpr = Columns.get();
-  } else {
-    assert(Attr.isArgExpr(1) &&
-           "Argument to should either be an identity or expression");
-    ColsExpr = Attr.getArgAsExpr(1);
-  }
+  assert(Attr.isArgExpr(1) && "Argument to should be an expression");
+  ColsExpr = Attr.getArgAsExpr(1);
 
   // Create the matrix type.
   QualType T = S.BuildMatrixType(CurType, RowsExpr, ColsExpr, Attr.getLoc());