/****************************************************************************** * Copyright (c) 2023, NVIDIA CORPORATION. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * Neither the name of the NVIDIA CORPORATION nor the * names of its contributors may be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL NVIDIA CORPORATION BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * ******************************************************************************/ /** * \file * cub::DeviceCopy provides device-wide, parallel operations for copying data. */ #pragma once #include #include #include #include CUB_NAMESPACE_BEGIN /** * @brief cub::DeviceCopy provides device-wide, parallel operations for copying data. * \ingroup SingleModule */ struct DeviceCopy { /** * @brief Copies data from a batch of given source ranges to their corresponding destination * ranges. * @note If any input range aliases any output range the behavior is undefined. If * any output range aliases another output range the behavior is undefined. Input * ranges can alias one another. * * @par Snippet * The code snippet below illustrates usage of DeviceCopy::Batched to perform a DeviceRunLength * Decode operation. * @par * @code * struct GetIteratorToRange * { * __host__ __device__ __forceinline__ auto operator()(uint32_t index) * { * return thrust::make_constant_iterator(d_data_in[index]); * } * int32_t *d_data_in; * }; * * struct GetPtrToRange * { * __host__ __device__ __forceinline__ auto operator()(uint32_t index) * { * return d_data_out + d_offsets[index]; * } * int32_t *d_data_out; * uint32_t *d_offsets; * }; * * struct GetRunLength * { * __host__ __device__ __forceinline__ uint32_t operator()(uint32_t index) * { * return d_offsets[index + 1] - d_offsets[index]; * } * uint32_t *d_offsets; * }; * * uint32_t num_ranges = 5; * int32_t *d_data_in; // e.g., [4, 2, 7, 3, 1] * int32_t *d_data_out; // e.g., [0, ... ] * uint32_t *d_offsets; // e.g., [0, 2, 5, 6, 9, 14] * * // Returns a constant iterator to the element of the i-th run * thrust::counting_iterator iota(0); * auto iterators_in = thrust::make_transform_iterator(iota, GetIteratorToRange{d_data_in}); * * // Returns the run length of the i-th run * auto sizes = thrust::make_transform_iterator(iota, GetRunLength{d_offsets}); * * // Returns pointers to the output range for each run * auto ptrs_out = thrust::make_transform_iterator(iota, GetPtrToRange{d_data_out, d_offsets}); * * // Determine temporary device storage requirements * void *d_temp_storage = nullptr; * size_t temp_storage_bytes = 0; * cub::DeviceCopy::Batched(d_temp_storage, temp_storage_bytes, iterators_in, ptrs_out, sizes, * num_ranges); * * // Allocate temporary storage * cudaMalloc(&d_temp_storage, temp_storage_bytes); * * // Run batched copy algorithm (used to perform runlength decoding) * cub::DeviceCopy::Batched(d_temp_storage, temp_storage_bytes, iterators_in, ptrs_out, sizes, * num_ranges); * * // d_data_out <-- [4, 4, 2, 2, 2, 7, 3, 3, 3, 1, 1, 1, 1, 1] * @endcode * @tparam InputIt [inferred] Device-accessible random-access input iterator type * providing the iterators to the source ranges * @tparam OutputIt [inferred] Device-accessible random-access input iterator type * providing the iterators to the destination ranges * @tparam SizeIteratorT [inferred] Device-accessible random-access input iterator * type providing the number of items to be copied for each pair of ranges * @param d_temp_storage [in] Device-accessible allocation of temporary storage. When NULL, the * required allocation size is written to \p temp_storage_bytes and no work is done. * @param temp_storage_bytes [in,out] Reference to size in bytes of \p d_temp_storage allocation * @param input_it [in] Device-accessible iterator providing the iterators to the source * ranges * @param output_it [in] Device-accessible iterator providing the iterators to the * destination ranges * @param sizes [in] Device-accessible iterator providing the number of elements to be copied * for each pair of ranges * @param num_ranges [in] The total number of range pairs * @param stream [in] [optional] CUDA stream to launch kernels within. Default is * stream0. */ template CUB_RUNTIME_FUNCTION static cudaError_t Batched(void *d_temp_storage, size_t &temp_storage_bytes, InputIt input_it, OutputIt output_it, SizeIteratorT sizes, uint32_t num_ranges, cudaStream_t stream = 0) { // Integer type large enough to hold any offset in [0, num_ranges) using RangeOffsetT = uint32_t; // Integer type large enough to hold any offset in [0, num_thread_blocks_launched), where a safe // uppper bound on num_thread_blocks_launched can be assumed to be given by // IDIV_CEIL(num_ranges, 64) using BlockOffsetT = uint32_t; return detail::DispatchBatchMemcpy::Dispatch(d_temp_storage, temp_storage_bytes, input_it, output_it, sizes, num_ranges, stream); } }; CUB_NAMESPACE_END