thread_search.cuh
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/******************************************************************************
* Copyright (c) 2011, Duane Merrill. All rights reserved.
* Copyright (c) 2011-2018, 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
* Thread utilities for sequential search
*/
#pragma once
#include "../util_namespace.cuh"
/// Optional outer namespace(s)
CUB_NS_PREFIX
/// CUB namespace
namespace cub {
/**
* Computes the begin offsets into A and B for the specific diagonal
*/
template <
typename AIteratorT,
typename BIteratorT,
typename OffsetT,
typename CoordinateT>
__host__ __device__ __forceinline__ void MergePathSearch(
OffsetT diagonal,
AIteratorT a,
BIteratorT b,
OffsetT a_len,
OffsetT b_len,
CoordinateT& path_coordinate)
{
/// The value type of the input iterator
typedef typename std::iterator_traits<AIteratorT>::value_type T;
OffsetT split_min = CUB_MAX(diagonal - b_len, 0);
OffsetT split_max = CUB_MIN(diagonal, a_len);
while (split_min < split_max)
{
OffsetT split_pivot = (split_min + split_max) >> 1;
if (a[split_pivot] <= b[diagonal - split_pivot - 1])
{
// Move candidate split range up A, down B
split_min = split_pivot + 1;
}
else
{
// Move candidate split range up B, down A
split_max = split_pivot;
}
}
path_coordinate.x = CUB_MIN(split_min, a_len);
path_coordinate.y = diagonal - split_min;
}
/**
* \brief Returns the offset of the first value within \p input which does not compare less than \p val
*/
template <
typename InputIteratorT,
typename OffsetT,
typename T>
__device__ __forceinline__ OffsetT LowerBound(
InputIteratorT input, ///< [in] Input sequence
OffsetT num_items, ///< [in] Input sequence length
T val) ///< [in] Search key
{
OffsetT retval = 0;
while (num_items > 0)
{
OffsetT half = num_items >> 1;
if (input[retval + half] < val)
{
retval = retval + (half + 1);
num_items = num_items - (half + 1);
}
else
{
num_items = half;
}
}
return retval;
}
/**
* \brief Returns the offset of the first value within \p input which compares greater than \p val
*/
template <
typename InputIteratorT,
typename OffsetT,
typename T>
__device__ __forceinline__ OffsetT UpperBound(
InputIteratorT input, ///< [in] Input sequence
OffsetT num_items, ///< [in] Input sequence length
T val) ///< [in] Search key
{
OffsetT retval = 0;
while (num_items > 0)
{
OffsetT half = num_items >> 1;
if (val < input[retval + half])
{
num_items = half;
}
else
{
retval = retval + (half + 1);
num_items = num_items - (half + 1);
}
}
return retval;
}
} // CUB namespace
CUB_NS_POSTFIX // Optional outer namespace(s)