diff --git a/clang/include/clang/Basic/DiagnosticDriverKinds.td b/clang/include/clang/Basic/DiagnosticDriverKinds.td
--- a/clang/include/clang/Basic/DiagnosticDriverKinds.td
+++ b/clang/include/clang/Basic/DiagnosticDriverKinds.td
@@ -253,6 +253,7 @@
   "unknown remark serializer format: '%0'">;
 def err_drv_no_neon_modifier : Error<"[no]neon is not accepted as modifier, please use [no]simd instead">;
 def err_drv_invalid_omp_target : Error<"OpenMP target is invalid: '%0'">;
+def err_drv_incompatible_omp_arch : Error<"OpenMP target architecture '%0' pointer size is incompatible with host '%1'">;
 def err_drv_omp_host_ir_file_not_found : Error<
   "The provided host compiler IR file '%0' is required to generate code for OpenMP target regions but cannot be found.">;
 def err_drv_omp_host_target_not_supported : Error<
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -3206,6 +3206,14 @@
             TT.getArch() == llvm::Triple::x86 ||
             TT.getArch() == llvm::Triple::x86_64))
         Diags.Report(diag::err_drv_invalid_omp_target) << A->getValue(i);
+      else if ((T.isArch64Bit() && TT.isArch32Bit()) ||
+               (T.isArch64Bit() && TT.isArch16Bit()) ||
+               (T.isArch32Bit() && TT.isArch64Bit()) ||
+               (T.isArch32Bit() && TT.isArch16Bit()) ||
+               (T.isArch16Bit() && TT.isArch32Bit()) ||
+               (T.isArch16Bit() && TT.isArch64Bit()))
+        Diags.Report(diag::err_drv_incompatible_omp_arch)
+            << A->getValue(i) << T.str();
       else
         Opts.OMPTargetTriples.push_back(TT);
     }
diff --git a/clang/test/OpenMP/nvptx_target_parallel_reduction_codegen_tbaa_PR46146.cpp b/clang/test/OpenMP/nvptx_target_parallel_reduction_codegen_tbaa_PR46146.cpp
--- a/clang/test/OpenMP/nvptx_target_parallel_reduction_codegen_tbaa_PR46146.cpp
+++ b/clang/test/OpenMP/nvptx_target_parallel_reduction_codegen_tbaa_PR46146.cpp
@@ -1,8 +1,8 @@
 // RUN: %clang_cc1 -x c++ -O1 -disable-llvm-optzns -verify -fopenmp -internal-isystem %S/../Headers/Inputs/include -internal-isystem %S/../../lib/Headers/openmp_wrappers -include __clang_openmp_device_functions.h -triple powerpc64le-unknown-unknown -fopenmp-targets=nvptx64-nvidia-cuda -emit-llvm-bc %s -o %t-ppc-host.bc
 // RUN: %clang_cc1 -x c++ -O1 -disable-llvm-optzns -verify -fopenmp -internal-isystem %S/../Headers/Inputs/include -internal-isystem %S/../../lib/Headers/openmp_wrappers -include __clang_openmp_device_functions.h -triple nvptx64-unknown-unknown -aux-triple powerpc64le-unknown-unknown  -fopenmp-targets=nvptx64-nvidia-cuda -emit-llvm %s -fopenmp-is-device -fopenmp-host-ir-file-path %t-ppc-host.bc -o - | FileCheck %s
 // RUN: %clang_cc1 -x c++ -O1 -disable-llvm-optzns -verify -fopenmp -internal-isystem %S/../Headers/Inputs/include -internal-isystem %S/../../lib/Headers/openmp_wrappers -include __clang_openmp_device_functions.h -triple i386-unknown-unknown -fopenmp-targets=nvptx-nvidia-cuda -emit-llvm-bc %s -o %t-x86-host.bc
-// RUN: %clang_cc1 -x c++ -O1 -disable-llvm-optzns -verify -fopenmp -internal-isystem %S/../Headers/Inputs/include -internal-isystem %S/../../lib/Headers/openmp_wrappers -include __clang_openmp_device_functions.h -triple nvptx-unknown-unknown -aux-triple powerpc64le-unknown-unknown -fopenmp-targets=nvptx-nvidia-cuda -emit-llvm %s -fopenmp-is-device -fopenmp-host-ir-file-path %t-x86-host.bc -o - | FileCheck %s
-// RUN: %clang_cc1 -x c++ -O1 -disable-llvm-optzns -verify -fopenmp -internal-isystem %S/../Headers/Inputs/include -internal-isystem %S/../../lib/Headers/openmp_wrappers -include __clang_openmp_device_functions.h -fexceptions -fcxx-exceptions -aux-triple powerpc64le-unknown-unknown -triple nvptx-unknown-unknown -fopenmp-targets=nvptx-nvidia-cuda -emit-llvm %s -fopenmp-is-device -fopenmp-host-ir-file-path %t-x86-host.bc -o - | FileCheck %s
+// RUN: %clang_cc1 -x c++ -O1 -disable-llvm-optzns -verify -fopenmp -internal-isystem %S/../Headers/Inputs/include -internal-isystem %S/../../lib/Headers/openmp_wrappers -include __clang_openmp_device_functions.h -triple nvptx64-unknown-unknown -aux-triple powerpc64le-unknown-unknown -fopenmp-targets=nvptx64-nvidia-cuda -emit-llvm %s -fopenmp-is-device -fopenmp-host-ir-file-path %t-x86-host.bc -o - | FileCheck %s
+// RUN: %clang_cc1 -x c++ -O1 -disable-llvm-optzns -verify -fopenmp -internal-isystem %S/../Headers/Inputs/include -internal-isystem %S/../../lib/Headers/openmp_wrappers -include __clang_openmp_device_functions.h -fexceptions -fcxx-exceptions -aux-triple powerpc64le-unknown-unknown -triple nvptx64-unknown-unknown -fopenmp-targets=nvptx64-nvidia-cuda -emit-llvm %s -fopenmp-is-device -fopenmp-host-ir-file-path %t-x86-host.bc -o - | FileCheck %s
 // expected-no-diagnostics
 #ifndef HEADER
 #define HEADER
diff --git a/clang/test/OpenMP/target_incompatible_architecture_messages.cpp b/clang/test/OpenMP/target_incompatible_architecture_messages.cpp
new file mode 100644
--- /dev/null
+++ b/clang/test/OpenMP/target_incompatible_architecture_messages.cpp
@@ -0,0 +1,14 @@
+// RUN: not %clang_cc1 -x c++ -fopenmp -triple powerpc64le-unknown-unknown -fopenmp-targets=nvptx-nvidia-cuda -o - %s 2>&1 | FileCheck %s
+// RUN: not %clang_cc1 -x c++ -fopenmp -triple i386-unknown-unknown -fopenmp-targets=nvptx64-nvidia-cuda -o - %s 2>&1 | FileCheck %s
+// RUN: not %clang_cc1 -x c++ -fopenmp -triple x86_64-unknown-unknown -fopenmp-targets=nvptx-nvidia-cuda -o - %s 2>&1 | FileCheck %s
+// RUN: not %clang_cc1 -x c++ -fopenmp -triple x86_64-unknown-unknown -fopenmp-targets=i386-pc-linux-gnu -o - %s 2>&1 | FileCheck %s
+// CHECK: error: OpenMP target architecture '{{.+}}' pointer size is incompatible with host '{{.+}}'
+#ifndef HEADER
+#define HEADER
+
+void test() {
+#pragma omp target
+  {}
+}
+
+#endif