diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
index 197a874eb180b..9dd1e860d7b59 100644
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -4328,9 +4328,13 @@ void CXXNameMangler::mangleRISCVFixedRVVVectorType(
 void CXXNameMangler::mangleType(const VectorType *T) {
   if ((T->getVectorKind() == VectorKind::Neon ||
        T->getVectorKind() == VectorKind::NeonPoly)) {
-    llvm::Triple Target = getASTContext().getTargetInfo().getTriple();
-    llvm::Triple::ArchType Arch =
-        getASTContext().getTargetInfo().getTriple().getArch();
+    const TargetInfo *TI = getASTContext().getLangOpts().isTargetDevice()
+                               ? getASTContext().getAuxTargetInfo()
+                               : &getASTContext().getTargetInfo();
+    if (!TI)
+      TI = &getASTContext().getTargetInfo();
+    llvm::Triple Target = TI->getTriple();
+    llvm::Triple::ArchType Arch = Target.getArch();
     if ((Arch == llvm::Triple::aarch64 ||
          Arch == llvm::Triple::aarch64_be) && !Target.isOSDarwin())
       mangleAArch64NeonVectorType(T);
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 9d2d41c1c6317..51bcb22f41ee8 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -8556,10 +8556,9 @@ static bool isPermittedNeonBaseType(QualType &Ty, VectorKind VecKind, Sema &S) {
   if (VecKind == VectorKind::NeonPoly) {
     if (IsPolyUnsigned) {
       // AArch64 polynomial vectors are unsigned.
-      return BTy->getKind() == BuiltinType::UChar ||
-             BTy->getKind() == BuiltinType::UShort ||
-             BTy->getKind() == BuiltinType::ULong ||
-             BTy->getKind() == BuiltinType::ULongLong;
+      auto bitwidth = S.Context.getTypeSize(BTy);
+      return BTy->isUnsignedInteger() &&
+             (bitwidth == 8 || bitwidth == 16 || bitwidth == 64);
     } else {
       // AArch32 polynomial vectors are signed.
       return BTy->getKind() == BuiltinType::SChar ||
diff --git a/clang/test/SemaSYCL/neon-polyvector-types.cpp b/clang/test/SemaSYCL/neon-polyvector-types.cpp
new file mode 100644
index 0000000000000..0dbd8206fd827
--- /dev/null
+++ b/clang/test/SemaSYCL/neon-polyvector-types.cpp
@@ -0,0 +1,22 @@
+// Does a run with a SYCL device, where neon polyvector type errors are ignored.
+// afterwards compile for the host where neon polyvector type errors aren't ignored
+
+// polyvector type errors get ignored with SYCL enabled
+// RUN: %clang_cc1 %s -fsycl-is-device -triple spir64 -aux-triple arm64-unknown-linux-gnu -target-feature +neon -fsyntax-only -verify=quiet
+
+// diagnostic for bad_poly32_t
+// RUN: %clang_cc1 %s -triple arm64-unknown-linux-gnu -target-feature +neon -fsyntax-only -verify
+typedef unsigned char poly8_t;
+typedef unsigned short poly16_t;
+typedef unsigned long poly64_t;
+
+typedef unsigned int bad_poly32_t;
+
+typedef __attribute__((neon_polyvector_type(16))) poly8_t poly8x16_t;
+typedef __attribute__((neon_polyvector_type(8))) poly16_t poly16x8_t;
+typedef __attribute__((neon_polyvector_type(2))) poly64_t poly64x2_t;
+
+// this error will get ignored when running SYCL
+// quiet-no-diagnostics
+typedef __attribute__((neon_polyvector_type(2))) bad_poly32_t bad_poly32x2_t;
+// expected-error@-1{{invalid vector element type}}