[ESIMD] Added a test on simd subscript operator (#323)

Author: DenisBakhvalov

SYCL/ESIMD/api/simd_subscript_operator.cpp

@@ -0,0 +1,98 @@
+//==----- simd_subscript_operator.cpp  - DPC++ ESIMD on-device test --------==//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// REQUIRES: gpu
+// UNSUPPORTED: cuda
+// RUN: %clangxx -fsycl %s -o %t.out
+// RUN: %GPU_RUN_PLACEHOLDER %t.out
+//
+// The test checks that it's possible to write through the simd subscript
+// operator. E.g.:
+//   simd<int, 4> v = 1;
+//   v[1] = 0; // v[1] returns writable simd_view
+
+#include "../esimd_test_utils.hpp"
+
+#include <CL/sycl.hpp>
+#include <sycl/ext/intel/experimental/esimd.hpp>
+
+#include <iostream>
+
+using namespace cl::sycl;
+using namespace sycl::ext::intel::experimental::esimd;
+
+int main(int argc, char **argv) {
+  queue q(esimd_test::ESIMDSelector{}, esimd_test::createExceptionHandler());
+
+  auto dev = q.get_device();
+  std::cout << "Running on " << dev.get_info<info::device::name>() << "\n";
+
+  constexpr unsigned VL = 16;
+
+  int A[VL];
+  int B[VL];
+  int gold[VL];
+
+  for (unsigned i = 0; i < VL; ++i) {
+    A[i] = -i;
+    B[i] = i;
+    gold[i] = B[i];
+  }
+
+  // some random indices to overwrite elements in B with elements from A.
+  std::array<int, 5> indicesToCopy = {2, 5, 9, 10, 13};
+
+  try {
+    buffer<int, 1> bufA(A, range<1>(VL));
+    buffer<int, 1> bufB(B, range<1>(VL));
+    range<1> glob_range{1};
+
+    auto e = q.submit([&](handler &cgh) {
+      auto PA = bufA.get_access<access::mode::read>(cgh);
+      auto PB = bufB.template get_access<access::mode::read_write>(cgh);
+      cgh.parallel_for<class Test>(glob_range, [=](id<1> i) SYCL_ESIMD_KERNEL {
+        using namespace sycl::ext::intel::experimental::esimd;
+        unsigned int offset = i * VL * sizeof(int);
+        simd<int, VL> va;
+        va.copy_from(PA, offset);
+        simd<int, VL> vb;
+        vb.copy_from(PB, offset);
+        for (auto idx : indicesToCopy)
+          vb[idx] = va[idx];
+        vb.copy_to(PB, offset);
+      });
+    });
+    q.wait_and_throw();
+  } catch (cl::sycl::exception const &e) {
+    std::cout << "SYCL exception caught: " << e.what() << '\n';
+    return e.get_cl_code();
+  }
+
+  int err_cnt = 0;
+
+  for (auto i : indicesToCopy)
+    gold[i] = A[i];
+
+  for (unsigned i = 0; i < VL; ++i) {
+    int val = B[i];
+
+    if (val != gold[i]) {
+      if (++err_cnt < 10) {
+        std::cout << "failed at index " << i << ": " << val << " != " << gold[i]
+                  << " (gold)\n";
+      }
+    }
+  }
+  if (err_cnt > 0) {
+    std::cout << "  pass rate: " << ((float)(VL - err_cnt) / (float)VL) * 100.0f
+              << "% (" << (VL - err_cnt) << "/" << VL << ")\n";
+  }
+
+  std::cout << (err_cnt > 0 ? "  FAILED\n" : "  Passed\n");
+
+  return err_cnt > 0 ? 1 : 0;
+}