block to ctile map for tall and skinny gemm

include/ck/tensor_operation/gpu/grid/block_to_ctile_map.hpp

@@ -658,6 +658,14 @@ struct BlockToCTileMap_3DGrid_KSplit
         return make_tuple(blockIdx.z, blockIdx.y, blockIdx.x);
     }
 
+    __host__ __device__ inline constexpr auto convert_1D_block_idx_to_3D_tuple(
+        const index_t& block_1d_id, const index_t& N, const index_t& k_batch) const
+    {
+        const auto Ndim = math::integer_divide_ceil(N, NPerBlock);
+        return make_tuple(((block_1d_id) / (k_batch * Ndim)),
+                          (((block_1d_id) / k_batch) % Ndim),
+                          (block_1d_id) % k_batch); // returns 3D tuple as (Mid,Nid,Kid)
+    }
     template <typename CTileIdx, typename CTileDim>
     __host__ __device__ bool ValidCTileIndex(const CTileIdx& /* c_tile_idx */,
                                              const CTileDim& /* c_tile_dim */) const