add example6 - find a 2d pattern in a distributed_mdarray

Author: haichangsi

src/CMakeLists.txt

@@ -26,3 +26,8 @@ add_executable(example3 example3.cpp)
 
 target_compile_definitions(example3 INTERFACE DR_FORMAT)
 target_link_libraries(example3 DR::mpi fmt::fmt)
+
+add_executable(example6 example6.cpp)
+
+target_compile_definitions(example6 INTERFACE DR_FORMAT)
+target_link_libraries(example6 DR::mpi fmt::fmt)

src/example6.cpp

@@ -0,0 +1,61 @@
+// SPDX-FileCopyrightText: Intel Corporation
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#include <dr/mhp.hpp>
+#include <fmt/core.h>
+
+namespace mhp = dr::mhp;
+
+using T = uint16_t;
+using MDA = dr::mhp::distributed_mdarray<T, 2>;
+
+int main() {
+#ifdef SYCL_LANGUAGE_VERSION
+  mhp::init(sycl::default_selector_v);
+#else
+  mhp::init();
+#endif
+  std::size_t arr_size = 7;
+  const std::size_t pattern_size = 2;
+  const std::size_t radius = pattern_size - 1;
+  std::array slice_starts{radius - 1, radius - 1};
+  std::array slice_ends{arr_size - radius, arr_size - radius};
+
+  auto dist = dr::mhp::distribution().halo(radius);
+  MDA a({arr_size, arr_size}, dist);
+  MDA occurrences_coords({arr_size, arr_size});
+
+  mhp::iota(a, 1);
+  mhp::transform(a, a.begin(), [](auto &&v) { return v % 2; });
+  mhp::fill(occurrences_coords, 0);
+
+  auto a_submdspan =
+      dr::mhp::views::submdspan(a.view(), slice_starts, slice_ends);
+  auto occurrences = dr::mhp::views::submdspan(occurrences_coords.view(),
+                                               slice_starts, slice_ends);
+  int pattern[pattern_size][pattern_size] = {{1, 0}, {0, 1}};
+
+  auto mdspan_pattern_op = [pattern](auto &&v) {
+    auto [a_submdspan, occurrences] = v;
+    if (pattern[0][0] == a_submdspan(0, 0) &&
+        pattern[0][1] == a_submdspan(0, 1) &&
+        pattern[1][0] == a_submdspan(1, 0) &&
+        pattern[1][1] == a_submdspan(1, 1)) {
+      occurrences(0, 0)++;
+    }
+  };
+
+  mhp::halo(a).exchange();
+  mhp::stencil_for_each(mdspan_pattern_op, a_submdspan, occurrences);
+
+  if (mhp::rank() == 0) {
+    fmt::print("a: \n{} \n", a.mdspan());
+    fmt::print("pattern: \n{} \n", pattern);
+    fmt::print("occurrences: \n{} \n", occurrences_coords.mdspan());
+  }
+
+  mhp::finalize();
+
+  return 0;
+}