cub/thread/thread_search.cuh
File members: cub/thread/thread_search.cuh
/******************************************************************************
* 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.
*
******************************************************************************/
#pragma once
#include <cub/config.cuh>
#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
# pragma GCC system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
# pragma clang system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
# pragma system_header
#endif // no system header
#include <cub/util_namespace.cuh>
#include <cub/util_type.cuh>
#include <iterator>
#include <nv/target>
CUB_NAMESPACE_BEGIN
template <typename AIteratorT, typename BIteratorT, typename OffsetT, typename CoordinateT>
_CCCL_HOST_DEVICE _CCCL_FORCEINLINE void MergePathSearch(
OffsetT diagonal, AIteratorT a, BIteratorT b, OffsetT a_len, OffsetT b_len, CoordinateT& path_coordinate)
{
using T = cub::detail::value_t<AIteratorT>;
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;
}
// TODO(bgruber): deprecate once ::cuda::std::lower_bound is made public
template <typename InputIteratorT, typename OffsetT, typename T>
_CCCL_DEVICE _CCCL_FORCEINLINE OffsetT LowerBound(InputIteratorT input, OffsetT num_items, T val)
{
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;
}
// TODO(bgruber): deprecate once ::cuda::std::upper_bound is made public
template <typename InputIteratorT, typename OffsetT, typename T>
_CCCL_DEVICE _CCCL_FORCEINLINE OffsetT UpperBound(InputIteratorT input, OffsetT num_items, T val)
{
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;
}
#if defined(__CUDA_FP16_TYPES_EXIST__)
template <typename InputIteratorT, typename OffsetT>
_CCCL_DEVICE _CCCL_FORCEINLINE OffsetT UpperBound(InputIteratorT input, OffsetT num_items, __half val)
{
OffsetT retval = 0;
while (num_items > 0)
{
OffsetT half = num_items >> 1;
bool lt;
NV_IF_TARGET(NV_PROVIDES_SM_53,
(lt = __hlt(val, input[retval + half]);),
(lt = __half2float(val) < __half2float(input[retval + half]);));
if (lt)
{
num_items = half;
}
else
{
retval = retval + (half + 1);
num_items = num_items - (half + 1);
}
}
return retval;
}
#endif // __CUDA_FP16_TYPES_EXIST__
CUB_NAMESPACE_END