| /****************************************************************************** | |
| * Copyright (c) 2011, Duane Merrill. All rights reserved. | |
| * Copyright (c) 2011-2018, NVIDIA CORPORATION. All rights reserved. | |
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| * derived from this software without specific prior written permission. | |
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| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND | |
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| * | |
| ******************************************************************************/ | |
| /** | |
| * \file | |
| * Thread utilities for sequential prefix scan over statically-sized array types | |
| */ | |
| #pragma once | |
| #include "../config.cuh" | |
| #include "../thread/thread_operators.cuh" | |
| CUB_NAMESPACE_BEGIN | |
| /// Internal namespace (to prevent ADL mishaps between static functions when mixing different CUB installations) | |
| namespace internal { | |
| /** | |
| * \addtogroup UtilModule | |
| * @{ | |
| */ | |
| /** | |
| * \name Sequential prefix scan over statically-sized array types | |
| * @{ | |
| */ | |
| template < | |
| int LENGTH, | |
| typename T, | |
| typename ScanOp> | |
| __device__ __forceinline__ T ThreadScanExclusive( | |
| T inclusive, | |
| T exclusive, | |
| T *input, ///< [in] Input array | |
| T *output, ///< [out] Output array (may be aliased to \p input) | |
| ScanOp scan_op, ///< [in] Binary scan operator | |
| Int2Type<LENGTH> /*length*/) | |
| { | |
| #pragma unroll | |
| for (int i = 0; i < LENGTH; ++i) | |
| { | |
| inclusive = scan_op(exclusive, input[i]); | |
| output[i] = exclusive; | |
| exclusive = inclusive; | |
| } | |
| return inclusive; | |
| } | |
| /** | |
| * \brief Perform a sequential exclusive prefix scan over \p LENGTH elements of the \p input array, seeded with the specified \p prefix. The aggregate is returned. | |
| * | |
| * \tparam LENGTH LengthT of \p input and \p output arrays | |
| * \tparam T <b>[inferred]</b> The data type to be scanned. | |
| * \tparam ScanOp <b>[inferred]</b> Binary scan operator type having member <tt>T operator()(const T &a, const T &b)</tt> | |
| */ | |
| template < | |
| int LENGTH, | |
| typename T, | |
| typename ScanOp> | |
| __device__ __forceinline__ T ThreadScanExclusive( | |
| T *input, ///< [in] Input array | |
| T *output, ///< [out] Output array (may be aliased to \p input) | |
| ScanOp scan_op, ///< [in] Binary scan operator | |
| T prefix, ///< [in] Prefix to seed scan with | |
| bool apply_prefix = true) ///< [in] Whether or not the calling thread should apply its prefix. If not, the first output element is undefined. (Handy for preventing thread-0 from applying a prefix.) | |
| { | |
| T inclusive = input[0]; | |
| if (apply_prefix) | |
| { | |
| inclusive = scan_op(prefix, inclusive); | |
| } | |
| output[0] = prefix; | |
| T exclusive = inclusive; | |
| return ThreadScanExclusive(inclusive, exclusive, input + 1, output + 1, scan_op, Int2Type<LENGTH - 1>()); | |
| } | |
| /** | |
| * \brief Perform a sequential exclusive prefix scan over the statically-sized \p input array, seeded with the specified \p prefix. The aggregate is returned. | |
| * | |
| * \tparam LENGTH <b>[inferred]</b> LengthT of \p input and \p output arrays | |
| * \tparam T <b>[inferred]</b> The data type to be scanned. | |
| * \tparam ScanOp <b>[inferred]</b> Binary scan operator type having member <tt>T operator()(const T &a, const T &b)</tt> | |
| */ | |
| template < | |
| int LENGTH, | |
| typename T, | |
| typename ScanOp> | |
| __device__ __forceinline__ T ThreadScanExclusive( | |
| T (&input)[LENGTH], ///< [in] Input array | |
| T (&output)[LENGTH], ///< [out] Output array (may be aliased to \p input) | |
| ScanOp scan_op, ///< [in] Binary scan operator | |
| T prefix, ///< [in] Prefix to seed scan with | |
| bool apply_prefix = true) ///< [in] Whether or not the calling thread should apply its prefix. (Handy for preventing thread-0 from applying a prefix.) | |
| { | |
| return ThreadScanExclusive<LENGTH>((T*) input, (T*) output, scan_op, prefix, apply_prefix); | |
| } | |
| template < | |
| int LENGTH, | |
| typename T, | |
| typename ScanOp> | |
| __device__ __forceinline__ T ThreadScanInclusive( | |
| T inclusive, | |
| T *input, ///< [in] Input array | |
| T *output, ///< [out] Output array (may be aliased to \p input) | |
| ScanOp scan_op, ///< [in] Binary scan operator | |
| Int2Type<LENGTH> /*length*/) | |
| { | |
| #pragma unroll | |
| for (int i = 0; i < LENGTH; ++i) | |
| { | |
| inclusive = scan_op(inclusive, input[i]); | |
| output[i] = inclusive; | |
| } | |
| return inclusive; | |
| } | |
| /** | |
| * \brief Perform a sequential inclusive prefix scan over \p LENGTH elements of the \p input array. The aggregate is returned. | |
| * | |
| * \tparam LENGTH LengthT of \p input and \p output arrays | |
| * \tparam T <b>[inferred]</b> The data type to be scanned. | |
| * \tparam ScanOp <b>[inferred]</b> Binary scan operator type having member <tt>T operator()(const T &a, const T &b)</tt> | |
| */ | |
| template < | |
| int LENGTH, | |
| typename T, | |
| typename ScanOp> | |
| __device__ __forceinline__ T ThreadScanInclusive( | |
| T *input, ///< [in] Input array | |
| T *output, ///< [out] Output array (may be aliased to \p input) | |
| ScanOp scan_op) ///< [in] Binary scan operator | |
| { | |
| T inclusive = input[0]; | |
| output[0] = inclusive; | |
| // Continue scan | |
| return ThreadScanInclusive(inclusive, input + 1, output + 1, scan_op, Int2Type<LENGTH - 1>()); | |
| } | |
| /** | |
| * \brief Perform a sequential inclusive prefix scan over the statically-sized \p input array. The aggregate is returned. | |
| * | |
| * \tparam LENGTH <b>[inferred]</b> LengthT of \p input and \p output arrays | |
| * \tparam T <b>[inferred]</b> The data type to be scanned. | |
| * \tparam ScanOp <b>[inferred]</b> Binary scan operator type having member <tt>T operator()(const T &a, const T &b)</tt> | |
| */ | |
| template < | |
| int LENGTH, | |
| typename T, | |
| typename ScanOp> | |
| __device__ __forceinline__ T ThreadScanInclusive( | |
| T (&input)[LENGTH], ///< [in] Input array | |
| T (&output)[LENGTH], ///< [out] Output array (may be aliased to \p input) | |
| ScanOp scan_op) ///< [in] Binary scan operator | |
| { | |
| return ThreadScanInclusive<LENGTH>((T*) input, (T*) output, scan_op); | |
| } | |
| /** | |
| * \brief Perform a sequential inclusive prefix scan over \p LENGTH elements of the \p input array, seeded with the specified \p prefix. The aggregate is returned. | |
| * | |
| * \tparam LENGTH LengthT of \p input and \p output arrays | |
| * \tparam T <b>[inferred]</b> The data type to be scanned. | |
| * \tparam ScanOp <b>[inferred]</b> Binary scan operator type having member <tt>T operator()(const T &a, const T &b)</tt> | |
| */ | |
| template < | |
| int LENGTH, | |
| typename T, | |
| typename ScanOp> | |
| __device__ __forceinline__ T ThreadScanInclusive( | |
| T *input, ///< [in] Input array | |
| T *output, ///< [out] Output array (may be aliased to \p input) | |
| ScanOp scan_op, ///< [in] Binary scan operator | |
| T prefix, ///< [in] Prefix to seed scan with | |
| bool apply_prefix = true) ///< [in] Whether or not the calling thread should apply its prefix. (Handy for preventing thread-0 from applying a prefix.) | |
| { | |
| T inclusive = input[0]; | |
| if (apply_prefix) | |
| { | |
| inclusive = scan_op(prefix, inclusive); | |
| } | |
| output[0] = inclusive; | |
| // Continue scan | |
| return ThreadScanInclusive(inclusive, input + 1, output + 1, scan_op, Int2Type<LENGTH - 1>()); | |
| } | |
| /** | |
| * \brief Perform a sequential inclusive prefix scan over the statically-sized \p input array, seeded with the specified \p prefix. The aggregate is returned. | |
| * | |
| * \tparam LENGTH <b>[inferred]</b> LengthT of \p input and \p output arrays | |
| * \tparam T <b>[inferred]</b> The data type to be scanned. | |
| * \tparam ScanOp <b>[inferred]</b> Binary scan operator type having member <tt>T operator()(const T &a, const T &b)</tt> | |
| */ | |
| template < | |
| int LENGTH, | |
| typename T, | |
| typename ScanOp> | |
| __device__ __forceinline__ T ThreadScanInclusive( | |
| T (&input)[LENGTH], ///< [in] Input array | |
| T (&output)[LENGTH], ///< [out] Output array (may be aliased to \p input) | |
| ScanOp scan_op, ///< [in] Binary scan operator | |
| T prefix, ///< [in] Prefix to seed scan with | |
| bool apply_prefix = true) ///< [in] Whether or not the calling thread should apply its prefix. (Handy for preventing thread-0 from applying a prefix.) | |
| { | |
| return ThreadScanInclusive<LENGTH>((T*) input, (T*) output, scan_op, prefix, apply_prefix); | |
| } | |
| //@} end member group | |
| /** @} */ // end group UtilModule | |
| } // internal namespace | |
| CUB_NAMESPACE_END | |