General 2D Reduction Kernel (#2535)

* General 2D Reduction Kernel

* Move the reduction kernel from the example
* Split the code and add the necessary policy, problem, shape files as
per ck_tile convention
* Add/modify the headers
* Modified the example to work with the 'new' kernel
* Added tests for the kernel
* N-D refernce reduce
* Added support for N-D input with transform to 2D
* Added padding to support various input sized tensors
* Bug fix in the thread buffer constructor
* Some comments to explain the reduce2d block kernel

* comments resolution

* clang-format

* comments resolution

* clang-format

* clang-format

* comments resolution

* clang-format

include/ck_tile/ops/reduce/pipeline/reduce2d_shape.hpp

@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2025, Advanced Micro Devices, Inc. All rights reserved.
+
+#pragma once
+
+#include "ck_tile/core.hpp"
+
+namespace ck_tile {
+
+template <typename BlockWarps, // num warps along seq<M, N>
+          typename BlockTile,  // block size, seq<M, N>
+          typename WarpTile,   // warp size, seq<M, N>
+          typename ThreadTile> // contiguous pixels(vector size) along seq<M, N>
+struct Reduce2dShape
+{
+    static constexpr index_t Block_M = BlockTile::at(number<0>{});
+    static constexpr index_t Block_N = BlockTile::at(number<1>{});
+
+    static constexpr index_t Warp_M = WarpTile::at(number<0>{});
+    static constexpr index_t Warp_N = WarpTile::at(number<1>{});
+
+    static constexpr index_t ThreadTile_M = ThreadTile::at(number<0>{});
+    static constexpr index_t ThreadTile_N = ThreadTile::at(number<1>{});
+
+    static constexpr index_t WarpPerBlock_M = BlockWarps::at(number<0>{});
+    static constexpr index_t WarpPerBlock_N = BlockWarps::at(number<1>{});
+
+    static constexpr index_t ThreadPerWarp_M = Warp_M / ThreadTile_M;
+    static constexpr index_t ThreadPerWarp_N = Warp_N / ThreadTile_N;
+
+    static constexpr index_t Repeat_M = Block_M / (WarpPerBlock_M * Warp_M);
+    static constexpr index_t Repeat_N = Block_N / (WarpPerBlock_N * Warp_N);
+
+    static constexpr index_t BlockSize =
+        ck_tile::get_warp_size() * reduce_on_sequence(BlockWarps{}, multiplies{}, number<1>{});
+};
+} // namespace ck_tile