diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 4d6e94df0b4de..66294c34a608a 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -12003,6 +12003,10 @@ class Sema final {
 
   ExprResult CheckBuiltinFunctionCall(FunctionDecl *FDecl,
                                       unsigned BuiltinID, CallExpr *TheCall);
+
+  bool CheckTSBuiltinFunctionCall(llvm::Triple::ArchType Arch,
+                                  unsigned BuiltinID, CallExpr *TheCall);
+
   void checkFortifiedBuiltinMemoryFunction(FunctionDecl *FD, CallExpr *TheCall);
 
   bool CheckARMBuiltinExclusiveCall(unsigned BuiltinID, CallExpr *TheCall,
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 478a534ab71c6..b4cb76d0b1ad4 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -1379,6 +1379,46 @@ CheckBuiltinTargetSupport(Sema &S, unsigned BuiltinID, CallExpr *TheCall,
 static void CheckNonNullArgument(Sema &S, const Expr *ArgExpr,
                                  SourceLocation CallSiteLoc);
 
+bool Sema::CheckTSBuiltinFunctionCall(llvm::Triple::ArchType Arch,
+                                      unsigned BuiltinID, CallExpr *TheCall) {
+  switch (Arch) {
+  default:
+    // Some builtins don't require additional checking, so just consider these
+    // acceptable.
+    return false;
+  case llvm::Triple::arm:
+  case llvm::Triple::armeb:
+  case llvm::Triple::thumb:
+  case llvm::Triple::thumbeb:
+    return CheckARMBuiltinFunctionCall(BuiltinID, TheCall);
+  case llvm::Triple::aarch64:
+  case llvm::Triple::aarch64_32:
+  case llvm::Triple::aarch64_be:
+    return CheckAArch64BuiltinFunctionCall(BuiltinID, TheCall);
+  case llvm::Triple::bpfeb:
+  case llvm::Triple::bpfel:
+    return CheckBPFBuiltinFunctionCall(BuiltinID, TheCall);
+  case llvm::Triple::hexagon:
+    return CheckHexagonBuiltinFunctionCall(BuiltinID, TheCall);
+  case llvm::Triple::mips:
+  case llvm::Triple::mipsel:
+  case llvm::Triple::mips64:
+  case llvm::Triple::mips64el:
+    return CheckMipsBuiltinFunctionCall(BuiltinID, TheCall);
+  case llvm::Triple::systemz:
+    return CheckSystemZBuiltinFunctionCall(BuiltinID, TheCall);
+  case llvm::Triple::x86:
+  case llvm::Triple::x86_64:
+    return CheckX86BuiltinFunctionCall(BuiltinID, TheCall);
+  case llvm::Triple::ppc:
+  case llvm::Triple::ppc64:
+  case llvm::Triple::ppc64le:
+    return CheckPPCBuiltinFunctionCall(BuiltinID, TheCall);
+  case llvm::Triple::amdgcn:
+    return CheckAMDGCNBuiltinFunctionCall(BuiltinID, TheCall);
+  }
+}
+
 ExprResult
 Sema::CheckBuiltinFunctionCall(FunctionDecl *FDecl, unsigned BuiltinID,
                                CallExpr *TheCall) {
@@ -1875,57 +1915,19 @@ Sema::CheckBuiltinFunctionCall(FunctionDecl *FDecl, unsigned BuiltinID,
   // Since the target specific builtins for each arch overlap, only check those
   // of the arch we are compiling for.
   if (Context.BuiltinInfo.isTSBuiltin(BuiltinID)) {
-    switch (Context.getTargetInfo().getTriple().getArch()) {
-      case llvm::Triple::arm:
-      case llvm::Triple::armeb:
-      case llvm::Triple::thumb:
-      case llvm::Triple::thumbeb:
-        if (CheckARMBuiltinFunctionCall(BuiltinID, TheCall))
-          return ExprError();
-        break;
-      case llvm::Triple::aarch64:
-      case llvm::Triple::aarch64_32:
-      case llvm::Triple::aarch64_be:
-        if (CheckAArch64BuiltinFunctionCall(BuiltinID, TheCall))
-          return ExprError();
-        break;
-      case llvm::Triple::bpfeb:
-      case llvm::Triple::bpfel:
-        if (CheckBPFBuiltinFunctionCall(BuiltinID, TheCall))
-          return ExprError();
-        break;
-      case llvm::Triple::hexagon:
-        if (CheckHexagonBuiltinFunctionCall(BuiltinID, TheCall))
-          return ExprError();
-        break;
-      case llvm::Triple::mips:
-      case llvm::Triple::mipsel:
-      case llvm::Triple::mips64:
-      case llvm::Triple::mips64el:
-        if (CheckMipsBuiltinFunctionCall(BuiltinID, TheCall))
-          return ExprError();
-        break;
-      case llvm::Triple::systemz:
-        if (CheckSystemZBuiltinFunctionCall(BuiltinID, TheCall))
-          return ExprError();
-        break;
-      case llvm::Triple::x86:
-      case llvm::Triple::x86_64:
-        if (CheckX86BuiltinFunctionCall(BuiltinID, TheCall))
-          return ExprError();
-        break;
-      case llvm::Triple::ppc:
-      case llvm::Triple::ppc64:
-      case llvm::Triple::ppc64le:
-        if (CheckPPCBuiltinFunctionCall(BuiltinID, TheCall))
-          return ExprError();
-        break;
-      case llvm::Triple::amdgcn:
-        if (CheckAMDGCNBuiltinFunctionCall(BuiltinID, TheCall))
-          return ExprError();
-        break;
-      default:
-        break;
+    if (Context.BuiltinInfo.isAuxBuiltinID(BuiltinID)) {
+      assert(Context.getAuxTargetInfo() &&
+             "Aux Target Builtin, but not an aux target?");
+
+      if (CheckTSBuiltinFunctionCall(
+              Context.getAuxTargetInfo()->getTriple().getArch(),
+              Context.BuiltinInfo.getAuxBuiltinID(BuiltinID), TheCall))
+        return ExprError();
+    } else {
+      if (CheckTSBuiltinFunctionCall(
+              Context.getTargetInfo().getTriple().getArch(), BuiltinID,
+              TheCall))
+        return ExprError();
     }
   }
 
diff --git a/clang/test/Sema/check-aux-builtins.c b/clang/test/Sema/check-aux-builtins.c
new file mode 100644
index 0000000000000..a9a836cdcbb71
--- /dev/null
+++ b/clang/test/Sema/check-aux-builtins.c
@@ -0,0 +1,5 @@
+// RUN: %clang_cc1 -fopenmp -fopenmp-is-device -triple aarch64 -aux-triple x86_64-linux-pc -fsyntax-only -verify %s
+
+void func(void) {
+  __builtin_cpu_is("INVALID"); // expected-error{{invalid cpu name for builtin}}
+}