diff --git a/clang/lib/Basic/Targets/AMDGPU.cpp b/clang/lib/Basic/Targets/AMDGPU.cpp
--- a/clang/lib/Basic/Targets/AMDGPU.cpp
+++ b/clang/lib/Basic/Targets/AMDGPU.cpp
@@ -462,9 +462,13 @@
   // supported by AMDGPU. Therefore keep its own format for these two types.
   auto SaveLongDoubleFormat = LongDoubleFormat;
   auto SaveFloat128Format = Float128Format;
+  auto SaveLongDoubleWidth = LongDoubleWidth;
+  auto SaveLongDoubleAlign = LongDoubleAlign;
   copyAuxTarget(Aux);
   LongDoubleFormat = SaveLongDoubleFormat;
   Float128Format = SaveFloat128Format;
+  LongDoubleWidth = SaveLongDoubleWidth;
+  LongDoubleAlign = SaveLongDoubleAlign;
   // For certain builtin types support on the host target, claim they are
   // support to pass the compilation of the host code during the device-side
   // compilation.
diff --git a/clang/test/CodeGenCUDA/long-double.cu b/clang/test/CodeGenCUDA/long-double.cu
new file mode 100644
--- /dev/null
+++ b/clang/test/CodeGenCUDA/long-double.cu
@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -triple amdgcn-amd-amdhsa -target-cpu gfx906 \
+// RUN:   -aux-triple x86_64-unknown-gnu-linux -fcuda-is-device \
+// RUN:   -emit-llvm -o - -x hip %s 2>&1 | FileCheck %s
+
+// RUN: %clang_cc1 -triple nvptx \
+// RUN:   -aux-triple x86_64-unknown-gnu-linux -fcuda-is-device \
+// RUN:   -emit-llvm -o - %s 2>&1 | FileCheck %s
+
+// CHECK: @_ZN15infinity_helperIeE5valueE = {{.*}} double 0x47EFFFFFD586B834, align 8
+// CHECK: @size = {{.*}} i32 8
+
+#include "Inputs/cuda.h"
+
+template <class> struct infinity_helper {};
+template <> struct infinity_helper<long double> { static constexpr long double value = 3.4028234e38L; };
+constexpr long double infinity_helper<long double>::value;
+__device__ int size = sizeof(long double);