[SYCL] Add test for atomic_ref operator= (#377)

Signed-off-by: John Pennycook <[email protected]>

Author: Pennycook

SYCL/AtomicRef/assignment.cpp

@@ -0,0 +1,56 @@
+// RUN: %clangxx -fsycl -fsycl-targets=%sycl_triple %s -o %t.out
+// RUN: %HOST_RUN_PLACEHOLDER %t.out
+// RUN: %CPU_RUN_PLACEHOLDER %t.out
+// RUN: %GPU_RUN_PLACEHOLDER %t.out
+
+#include <CL/sycl.hpp>
+#include <algorithm>
+#include <cassert>
+#include <numeric>
+#include <vector>
+using namespace sycl;
+using namespace sycl::ONEAPI;
+
+template <typename T> class assignment_kernel;
+
+template <typename T> void assignment_test(queue q, size_t N) {
+  T initial = T(N);
+  T assignment = initial;
+  {
+    buffer<T> assignment_buf(&assignment, 1);
+    q.submit([&](handler &cgh) {
+      auto st =
+          assignment_buf.template get_access<access::mode::read_write>(cgh);
+      cgh.parallel_for<assignment_kernel<T>>(range<1>(N), [=](item<1> it) {
+        size_t gid = it.get_id(0);
+        auto atm = atomic_ref<T, ONEAPI::memory_order::relaxed,
+                              ONEAPI::memory_scope::device,
+                              access::address_space::global_space>(st[0]);
+        atm = T(gid);
+      });
+    });
+  }
+
+  // The initial value should have been overwritten by a work-item ID
+  // Atomicity isn't tested here, but support for assignment() is
+  assert(assignment != initial);
+  assert(assignment >= T(0) && assignment <= T(N - 1));
+}
+
+int main() {
+  queue q;
+  std::string version = q.get_device().get_info<info::device::version>();
+
+  constexpr int N = 32;
+  assignment_test<int>(q, N);
+  assignment_test<unsigned int>(q, N);
+  assignment_test<long>(q, N);
+  assignment_test<unsigned long>(q, N);
+  assignment_test<long long>(q, N);
+  assignment_test<unsigned long long>(q, N);
+  assignment_test<float>(q, N);
+  assignment_test<double>(q, N);
+  assignment_test<char *>(q, N);
+
+  std::cout << "Test passed." << std::endl;
+}