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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
* cub::DeviceScan provides device-wide, parallel operations for computing a prefix scan across a sequence of data items residing within device-accessible memory.
*/
#pragma once
#include <stdio.h>
#include <iterator>
#include "../../agent/agent_scan.cuh"
#include "../../thread/thread_operators.cuh"
#include "../../grid/grid_queue.cuh"
#include "../../config.cuh"
#include "../../util_debug.cuh"
#include "../../util_device.cuh"
#include <thrust/system/cuda/detail/core/triple_chevron_launch.h>
/// Optional outer namespace(s)
CUB_NS_PREFIX
/// CUB namespace
namespace cub {
/******************************************************************************
* Kernel entry points
*****************************************************************************/
/**
* Initialization kernel for tile status initialization (multi-block)
*/
template <
typename ScanTileStateT> ///< Tile status interface type
__global__ void DeviceScanInitKernel(
ScanTileStateT tile_state, ///< [in] Tile status interface
int num_tiles) ///< [in] Number of tiles
{
// Initialize tile status
tile_state.InitializeStatus(num_tiles);
}
/**
* Initialization kernel for tile status initialization (multi-block)
*/
template <
typename ScanTileStateT, ///< Tile status interface type
typename NumSelectedIteratorT> ///< Output iterator type for recording the number of items selected
__global__ void DeviceCompactInitKernel(
ScanTileStateT tile_state, ///< [in] Tile status interface
int num_tiles, ///< [in] Number of tiles
NumSelectedIteratorT d_num_selected_out) ///< [out] Pointer to the total number of items selected (i.e., length of \p d_selected_out)
{
// Initialize tile status
tile_state.InitializeStatus(num_tiles);
// Initialize d_num_selected_out
if ((blockIdx.x == 0) && (threadIdx.x == 0))
*d_num_selected_out = 0;
}
/**
* Scan kernel entry point (multi-block)
*/
template <
typename ScanPolicyT, ///< Parameterized ScanPolicyT tuning policy type
typename InputIteratorT, ///< Random-access input iterator type for reading scan inputs \iterator
typename OutputIteratorT, ///< Random-access output iterator type for writing scan outputs \iterator
typename ScanTileStateT, ///< Tile status interface type
typename ScanOpT, ///< Binary scan functor type having member <tt>T operator()(const T &a, const T &b)</tt>
typename InitValueT, ///< Initial value to seed the exclusive scan (cub::NullType for inclusive scans)
typename OffsetT> ///< Signed integer type for global offsets
__launch_bounds__ (int(ScanPolicyT::BLOCK_THREADS))
__global__ void DeviceScanKernel(
InputIteratorT d_in, ///< Input data
OutputIteratorT d_out, ///< Output data
ScanTileStateT tile_state, ///< Tile status interface
int start_tile, ///< The starting tile for the current grid
ScanOpT scan_op, ///< Binary scan functor
InitValueT init_value, ///< Initial value to seed the exclusive scan
OffsetT num_items) ///< Total number of scan items for the entire problem
{
// Thread block type for scanning input tiles
typedef AgentScan<
ScanPolicyT,
InputIteratorT,
OutputIteratorT,
ScanOpT,
InitValueT,
OffsetT> AgentScanT;
// Shared memory for AgentScan
__shared__ typename AgentScanT::TempStorage temp_storage;
// Process tiles
AgentScanT(temp_storage, d_in, d_out, scan_op, init_value).ConsumeRange(
num_items,
tile_state,
start_tile);
}
/******************************************************************************
* Policy
******************************************************************************/
template <
typename OutputT> ///< Data type
struct DeviceScanPolicy
{
/// SM10
struct Policy100 : ChainedPolicy<100, Policy100, Policy100>
{
typedef AgentScanPolicy<
64, 9, ///< Threads per block, items per thread
OutputT,
BLOCK_LOAD_WARP_TRANSPOSE,
LOAD_DEFAULT,
BLOCK_STORE_WARP_TRANSPOSE,
BLOCK_SCAN_WARP_SCANS>
ScanPolicyT;
};
/// SM13
struct Policy130 : ChainedPolicy<130, Policy130, Policy100>
{
typedef AgentScanPolicy<
96, 21, ///< Threads per block, items per thread
OutputT,
BLOCK_LOAD_WARP_TRANSPOSE,
LOAD_DEFAULT,
BLOCK_STORE_WARP_TRANSPOSE,
BLOCK_SCAN_RAKING_MEMOIZE>
ScanPolicyT;
};
/// SM20
struct Policy200 : ChainedPolicy<200, Policy200, Policy130>
{
// GTX 580: 20.3B items/s (162.3 GB/s) @ 48M 32-bit T
typedef AgentScanPolicy<
128, 12, ///< Threads per block, items per thread
OutputT,
BLOCK_LOAD_WARP_TRANSPOSE,
LOAD_DEFAULT,
BLOCK_STORE_WARP_TRANSPOSE,
BLOCK_SCAN_WARP_SCANS>
ScanPolicyT;
};
/// SM30
struct Policy300 : ChainedPolicy<300, Policy300, Policy200>
{
typedef AgentScanPolicy<
256, 9, ///< Threads per block, items per thread
OutputT,
BLOCK_LOAD_WARP_TRANSPOSE,
LOAD_DEFAULT,
BLOCK_STORE_WARP_TRANSPOSE,
BLOCK_SCAN_WARP_SCANS>
ScanPolicyT;
};
/// SM35
struct Policy350 : ChainedPolicy<350, Policy350, Policy300>
{
// GTX Titan: 29.5B items/s (232.4 GB/s) @ 48M 32-bit T
typedef AgentScanPolicy<
128, 12, ///< Threads per block, items per thread
OutputT,
BLOCK_LOAD_DIRECT,
LOAD_LDG,
BLOCK_STORE_WARP_TRANSPOSE_TIMESLICED,
BLOCK_SCAN_RAKING>
ScanPolicyT;
};
/// SM520
struct Policy520 : ChainedPolicy<520, Policy520, Policy350>
{
// Titan X: 32.47B items/s @ 48M 32-bit T
typedef AgentScanPolicy<
128, 12, ///< Threads per block, items per thread
OutputT,
BLOCK_LOAD_DIRECT,
LOAD_LDG,
BLOCK_STORE_WARP_TRANSPOSE,
BLOCK_SCAN_WARP_SCANS>
ScanPolicyT;
};
/// SM600
struct Policy600 : ChainedPolicy<600, Policy600, Policy520>
{
typedef AgentScanPolicy<
128, 15, ///< Threads per block, items per thread
OutputT,
BLOCK_LOAD_TRANSPOSE,
LOAD_DEFAULT,
BLOCK_STORE_TRANSPOSE,
BLOCK_SCAN_WARP_SCANS>
ScanPolicyT;
};
/// MaxPolicy
typedef Policy600 MaxPolicy;
};
/******************************************************************************
* Dispatch
******************************************************************************/
/**
* Utility class for dispatching the appropriately-tuned kernels for DeviceScan
*/
template <
typename InputIteratorT, ///< Random-access input iterator type for reading scan inputs \iterator
typename OutputIteratorT, ///< Random-access output iterator type for writing scan outputs \iterator
typename ScanOpT, ///< Binary scan functor type having member <tt>T operator()(const T &a, const T &b)</tt>
typename InitValueT, ///< The init_value element type for ScanOpT (cub::NullType for inclusive scans)
typename OffsetT, ///< Signed integer type for global offsets
typename SelectedPolicy = DeviceScanPolicy<
typename If<(Equals<typename std::iterator_traits<OutputIteratorT>::value_type, void>::VALUE), // OutputT = (if output iterator's value type is void) ?
typename std::iterator_traits<InputIteratorT>::value_type, // ... then the input iterator's value type,
typename std::iterator_traits<OutputIteratorT>::value_type>::Type> >
struct DispatchScan:
SelectedPolicy
{
//---------------------------------------------------------------------
// Constants and Types
//---------------------------------------------------------------------
enum
{
INIT_KERNEL_THREADS = 128
};
// The output value type
typedef typename If<(Equals<typename std::iterator_traits<OutputIteratorT>::value_type, void>::VALUE), // OutputT = (if output iterator's value type is void) ?
typename std::iterator_traits<InputIteratorT>::value_type, // ... then the input iterator's value type,
typename std::iterator_traits<OutputIteratorT>::value_type>::Type OutputT; // ... else the output iterator's value type
void* 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.
size_t& temp_storage_bytes; ///< [in,out] Reference to size in bytes of \p d_temp_storage allocation
InputIteratorT d_in; ///< [in] Pointer to the input sequence of data items
OutputIteratorT d_out; ///< [out] Pointer to the output sequence of data items
ScanOpT scan_op; ///< [in] Binary scan functor
InitValueT init_value; ///< [in] Initial value to seed the exclusive scan
OffsetT num_items; ///< [in] Total number of input items (i.e., the length of \p d_in)
cudaStream_t stream; ///< [in] <b>[optional]</b> CUDA stream to launch kernels within. Default is stream<sub>0</sub>.
bool debug_synchronous;
int ptx_version;
CUB_RUNTIME_FUNCTION __forceinline__
DispatchScan(
void* 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.
size_t& temp_storage_bytes, ///< [in,out] Reference to size in bytes of \p d_temp_storage allocation
InputIteratorT d_in, ///< [in] Pointer to the input sequence of data items
OutputIteratorT d_out, ///< [out] Pointer to the output sequence of data items
OffsetT num_items, ///< [in] Total number of input items (i.e., the length of \p d_in)
ScanOpT scan_op, ///< [in] Binary scan functor
InitValueT init_value, ///< [in] Initial value to seed the exclusive scan
cudaStream_t stream, ///< [in] <b>[optional]</b> CUDA stream to launch kernels within. Default is stream<sub>0</sub>.
bool debug_synchronous,
int ptx_version
):
d_temp_storage(d_temp_storage),
temp_storage_bytes(temp_storage_bytes),
d_in(d_in),
d_out(d_out),
num_items(num_items),
scan_op(scan_op),
init_value(init_value),
stream(stream),
debug_synchronous(debug_synchronous),
ptx_version(ptx_version)
{}
template <typename ActivePolicyT, typename InitKernel, typename ScanKernel>
CUB_RUNTIME_FUNCTION __host__ __forceinline__
cudaError_t Invoke(InitKernel init_kernel, ScanKernel scan_kernel)
{
#ifndef CUB_RUNTIME_ENABLED
(void)init_kernel;
(void)scan_kernel;
// Kernel launch not supported from this device
return CubDebug(cudaErrorNotSupported);
#else
typedef typename ActivePolicyT::ScanPolicyT Policy;
typedef typename cub::ScanTileState<OutputT> ScanTileStateT;
cudaError error = cudaSuccess;
do
{
// Get device ordinal
int device_ordinal;
if (CubDebug(error = cudaGetDevice(&device_ordinal))) break;
// Get SM count
int sm_count;
if (CubDebug(error = cudaDeviceGetAttribute (&sm_count, cudaDevAttrMultiProcessorCount, device_ordinal))) break;
// Number of input tiles
int tile_size = Policy::BLOCK_THREADS * Policy::ITEMS_PER_THREAD;
int num_tiles = (num_items + tile_size - 1) / tile_size;
// Specify temporary storage allocation requirements
size_t allocation_sizes[1];
if (CubDebug(error = ScanTileStateT::AllocationSize(num_tiles, allocation_sizes[0]))) break; // bytes needed for tile status descriptors
// Compute allocation pointers into the single storage blob (or compute the necessary size of the blob)
void* allocations[1] = {};
if (CubDebug(error = AliasTemporaries(d_temp_storage, temp_storage_bytes, allocations, allocation_sizes))) break;
if (d_temp_storage == NULL)
{
// Return if the caller is simply requesting the size of the storage allocation
break;
}
// Return if empty problem
if (num_items == 0)
break;
// Construct the tile status interface
ScanTileStateT tile_state;
if (CubDebug(error = tile_state.Init(num_tiles, allocations[0], allocation_sizes[0]))) break;
// Log init_kernel configuration
int init_grid_size = (num_tiles + INIT_KERNEL_THREADS - 1) / INIT_KERNEL_THREADS;
if (debug_synchronous) _CubLog("Invoking init_kernel<<<%d, %d, 0, %lld>>>()\n", init_grid_size, INIT_KERNEL_THREADS, (long long) stream);
// Invoke init_kernel to initialize tile descriptors
thrust::cuda_cub::launcher::triple_chevron(
init_grid_size, INIT_KERNEL_THREADS, 0, stream
).doit(init_kernel,
tile_state,
num_tiles);
// Check for failure to launch
if (CubDebug(error = cudaPeekAtLastError())) break;
// Sync the stream if specified to flush runtime errors
if (debug_synchronous && (CubDebug(error = SyncStream(stream)))) break;
// Get SM occupancy for scan_kernel
int scan_sm_occupancy;
if (CubDebug(error = MaxSmOccupancy(
scan_sm_occupancy, // out
scan_kernel,
Policy::BLOCK_THREADS))) break;
// Get max x-dimension of grid
int max_dim_x;
if (CubDebug(error = cudaDeviceGetAttribute(&max_dim_x, cudaDevAttrMaxGridDimX, device_ordinal))) break;;
// Run grids in epochs (in case number of tiles exceeds max x-dimension
int scan_grid_size = CUB_MIN(num_tiles, max_dim_x);
for (int start_tile = 0; start_tile < num_tiles; start_tile += scan_grid_size)
{
// Log scan_kernel configuration
if (debug_synchronous) _CubLog("Invoking %d scan_kernel<<<%d, %d, 0, %lld>>>(), %d items per thread, %d SM occupancy\n",
start_tile, scan_grid_size, Policy::BLOCK_THREADS, (long long) stream, Policy::ITEMS_PER_THREAD, scan_sm_occupancy);
// Invoke scan_kernel
thrust::cuda_cub::launcher::triple_chevron(
scan_grid_size, Policy::BLOCK_THREADS, 0, stream
).doit(scan_kernel,
d_in,
d_out,
tile_state,
start_tile,
scan_op,
init_value,
num_items);
// Check for failure to launch
if (CubDebug(error = cudaPeekAtLastError())) break;
// Sync the stream if specified to flush runtime errors
if (debug_synchronous && (CubDebug(error = SyncStream(stream)))) break;
}
}
while (0);
return error;
#endif // CUB_RUNTIME_ENABLED
}
template <typename ActivePolicyT>
CUB_RUNTIME_FUNCTION __host__ __forceinline__
cudaError_t Invoke()
{
typedef typename ActivePolicyT::ScanPolicyT Policy;
typedef typename cub::ScanTileState<OutputT> ScanTileStateT;
// Ensure kernels are instantiated.
return Invoke<ActivePolicyT>(
DeviceScanInitKernel<ScanTileStateT>,
DeviceScanKernel<Policy, InputIteratorT, OutputIteratorT, ScanTileStateT, ScanOpT, InitValueT, OffsetT>
);
}
/**
* Internal dispatch routine
*/
CUB_RUNTIME_FUNCTION __forceinline__
static cudaError_t Dispatch(
void* 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.
size_t& temp_storage_bytes, ///< [in,out] Reference to size in bytes of \p d_temp_storage allocation
InputIteratorT d_in, ///< [in] Pointer to the input sequence of data items
OutputIteratorT d_out, ///< [out] Pointer to the output sequence of data items
ScanOpT scan_op, ///< [in] Binary scan functor
InitValueT init_value, ///< [in] Initial value to seed the exclusive scan
OffsetT num_items, ///< [in] Total number of input items (i.e., the length of \p d_in)
cudaStream_t stream, ///< [in] <b>[optional]</b> CUDA stream to launch kernels within. Default is stream<sub>0</sub>.
bool debug_synchronous) ///< [in] <b>[optional]</b> Whether or not to synchronize the stream after every kernel launch to check for errors. Also causes launch configurations to be printed to the console. Default is \p false.
{
typedef typename DispatchScan::MaxPolicy MaxPolicyT;
cudaError_t error;
do
{
// Get PTX version
int ptx_version = 0;
if (CubDebug(error = PtxVersion(ptx_version))) break;
// Create dispatch functor
DispatchScan dispatch(
d_temp_storage,
temp_storage_bytes,
d_in,
d_out,
num_items,
scan_op,
init_value,
stream,
debug_synchronous,
ptx_version
);
// Dispatch to chained policy
if (CubDebug(error = MaxPolicyT::Invoke(ptx_version, dispatch))) break;
}
while (0);
return error;
}
};
} // CUB namespace
CUB_NS_POSTFIX // Optional outer namespace(s)