[SYCL] Add regression test for get_local_linear_id

SYCL/Regression/group_local_linear_id.cpp

@@ -0,0 +1,33 @@
+// RUN: %clangxx -fsycl -fsycl-targets=%sycl_triple %s -o %t.out
+// RUN: %CPU_RUN_PLACEHOLDER %t.out
+// RUN: %GPU_RUN_PLACEHOLDER %t.out
+// RUN: %ACC_RUN_PLACEHOLDER %t.out
+
+// Checks that get_local_linear_id is the same on the nd_item as on the
+// corresponding group.
+
+#include <iostream>
+#include <sycl/sycl.hpp>
+
+int main() {
+  const sycl::range<3> GlobalRange(2, 8, 16);
+  const sycl::range<3> LocalRange(2, 4, 4);
+  sycl::queue Q;
+  bool *ReadSame = sycl::malloc_shared<bool>(GlobalRange.size(), Q);
+  Q.parallel_for(sycl::nd_range<3>{GlobalRange, LocalRange},
+                 [=](sycl::nd_item<3> Item) {
+                   ReadSame[Item.get_global_linear_id()] =
+                       Item.get_local_linear_id() ==
+                       Item.get_group().get_local_linear_id();
+                 })
+      .wait();
+  int Failures = 0;
+  for (size_t I = 0; I < GlobalRange.size(); ++I) {
+    if (ReadSame[I])
+      continue;
+    ++Failures;
+    std::cout << "Read mismatch at index " << I << std::endl;
+  }
+  sycl::free(ReadSame, Q);
+  return Failures;
+}