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* Copyright (c) 2011-2022, 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::AgentBatchMemcpy implements device-wide copying of a batch of device-accessible
* source-buffers to device-accessible destination-buffers.
*/
#pragma once
#include <cub/agent/single_pass_scan_operators.cuh>
#include <cub/block/block_exchange.cuh>
#include <cub/block/block_load.cuh>
#include <cub/block/block_run_length_decode.cuh>
#include <cub/block/block_scan.cuh>
#include <cub/block/block_store.cuh>
#include <cub/util_ptx.cuh>
#include <cub/util_type.cuh>
#include <cuda/std/type_traits>
#include <cstdint>
CUB_NAMESPACE_BEGIN
namespace detail
{
template <bool PTR_IS_FOUR_BYTE_ALIGNED>
__forceinline__ __device__ void LoadVectorAndFunnelShiftR(uint32_t const *aligned_ptr,
uint32_t bit_shift,
uint4 &data_out)
{
data_out = {aligned_ptr[0], aligned_ptr[1], aligned_ptr[2], aligned_ptr[3]};
if (!PTR_IS_FOUR_BYTE_ALIGNED)
{
uint32_t tail = aligned_ptr[4];
data_out.x = __funnelshift_r(data_out.x, data_out.y, bit_shift);
data_out.y = __funnelshift_r(data_out.y, data_out.z, bit_shift);
data_out.z = __funnelshift_r(data_out.z, data_out.w, bit_shift);
data_out.w = __funnelshift_r(data_out.w, tail, bit_shift);
}
}
template <bool PTR_IS_FOUR_BYTE_ALIGNED>
__forceinline__ __device__ void LoadVectorAndFunnelShiftR(uint32_t const *aligned_ptr,
uint32_t bit_shift,
uint2 &data_out)
{
data_out = {aligned_ptr[0], aligned_ptr[1]};
if (!PTR_IS_FOUR_BYTE_ALIGNED)
{
uint32_t tail = aligned_ptr[2];
data_out.x = __funnelshift_r(data_out.x, data_out.y, bit_shift);
data_out.y = __funnelshift_r(data_out.y, tail, bit_shift);
}
}
template <bool PTR_IS_FOUR_BYTE_ALIGNED>
__forceinline__ __device__ void LoadVectorAndFunnelShiftR(uint32_t const *aligned_ptr,
uint32_t bit_shift,
uint32_t &data_out)
{
data_out = aligned_ptr[0];
if (!PTR_IS_FOUR_BYTE_ALIGNED)
{
uint32_t tail = aligned_ptr[1];
data_out = __funnelshift_r(data_out, tail, bit_shift);
}
}
/**
* @brief Loads data from \p ptr into \p data_out without requiring \p ptr to be aligned.
* @note If \p ptr isn't aligned to four bytes, the bytes from the last four-byte aligned address up
* to \p ptr are loaded too (but dropped) and, hence, need to be device-accessible. Similarly, if
* \p ptr isn't aligned to four bytes, the bytes from `(ptr + sizeof(VectorT))` up to the following
* four-byte aligned address are loaded too (but dropped), and, hence, need to be device-accessible.
*
* @tparam VectorT The vector type used for vectorized stores (i.e., one of uint4, uint2, uint32_t)
* @param ptr The pointer from which the data is supposed to be loaded
* @param data_out The vector type that stores the data loaded from \p ptr
*/
template <typename VectorT>
__forceinline__ __device__ void LoadVector(const char *ptr, VectorT &data_out)
{
const uint32_t offset = reinterpret_cast<std::uintptr_t>(ptr) % 4U;
const uint32_t *aligned_ptr = reinterpret_cast<uint32_t const *>(ptr - offset);
constexpr uint32_t bits_per_byte = 8U;
const uint32_t bit_shift = offset * bits_per_byte;
// If `ptr` is aligned to four bytes, we can perform a simple uint32_t-aliased load
if (offset == 0)
{
LoadVectorAndFunnelShiftR<true>(aligned_ptr, bit_shift, data_out);
}
// Otherwise, we need to load extra bytes and perform funnel-shifting
else
{
LoadVectorAndFunnelShiftR<false>(aligned_ptr, bit_shift, data_out);
}
}
/**
* @brief Helper data structure to hold information on the byte range for which we can safely
* perform vectorized copies.
*
* @tparam VectorT The vector type used for vectorized stores (i.e., one of uint4, uint2, uint32_t)
*/
template <typename VectorT>
struct PointerRange
{
VectorT *out_begin;
VectorT *out_end;
const char *in_begin;
const char *in_end;
};
/**
* @brief Both `out_start_aligned` and `out_end_aligned` are indices into `out_ptr`.
* `out_start_aligned` is the first VectorT-aligned memory location after `out_ptr + 3`.
* `out_end_aligned` is the last VectorT-aligned memory location before `out_end - 4`, where out_end
* corresponds to one past the last byte to be copied. Bytes between `[out_start_aligned,
* out_end_aligned)` will be copied using VectorT. `out_ptr + 3` and `out_end - 4` are used instead
* of `out_ptr` and `out_end` to avoid `LoadVector` reading beyond data boundaries.
*
* @tparam VectorT The vector type used for vectorized stores (i.e., one of uint4, uint2, uint32_t)
* @tparam ByteOffsetT Type used to index the bytes within the buffers
* @param in_begin Pointer to the beginning of the byte range that shall be copied
* @param out_begin Pointer to the beginning of the byte range that shall be copied
* @param num_bytes Number of bytes that shall be copied
* @return The byte range that can safely be copied using vectorized stores of type VectorT
*/
template <typename VectorT, typename ByteOffsetT>
__device__ __forceinline__ PointerRange<VectorT> GetAlignedPtrs(const void *in_begin,
void *out_begin,
ByteOffsetT num_bytes)
{
// Data type size used for vectorized stores
constexpr size_t out_datatype_size = sizeof(VectorT);
// Data type size used for type-aliased loads
constexpr size_t in_datatype_size = sizeof(uint32_t);
// char-aliased ptrs to simplify pointer arithmetic
char *out_ptr = reinterpret_cast<char *>(out_begin);
const char *in_ptr = reinterpret_cast<const char *>(in_begin);
// Number of bytes between the first VectorT-aligned address at or before out_begin and out_begin
const uint32_t alignment_offset = reinterpret_cast<std::uintptr_t>(out_ptr) % out_datatype_size;
// The first VectorT-aligned address before (or at) out_begin
char *out_chars_aligned = reinterpret_cast<char *>(out_ptr - alignment_offset);
// The number of extra bytes preceding `in_ptr` that are loaded but dropped
uint32_t in_extra_bytes = reinterpret_cast<std::uintptr_t>(in_ptr) % in_datatype_size;
// The offset required by `LoadVector`:
// If the input pointer is not aligned, we load data from the last aligned address preceding the
// pointer. That is, loading up to (in_datatype_size-1) bytes before `in_ptr`
uint32_t in_offset_req = in_extra_bytes;
// Bytes after `out_chars_aligned` to the first VectorT-aligned address at or after `out_begin`
uint32_t out_start_aligned =
CUB_QUOTIENT_CEILING(in_offset_req + alignment_offset, out_datatype_size) * out_datatype_size;
// Compute the beginning of the aligned ranges (output and input pointers)
VectorT *out_aligned_begin = reinterpret_cast<VectorT *>(out_chars_aligned + out_start_aligned);
const char *in_aligned_begin = in_ptr + (reinterpret_cast<char *>(out_aligned_begin) - out_ptr);
// If the aligned range is not aligned for the input pointer, we load up to (in_datatype_size-1)
// bytes after the last byte that is copied. That is, we always load four bytes up to the next
// aligned input address at a time. E.g., if the last byte loaded is one byte past the last
// aligned address we'll also load the three bytes after that byte.
uint32_t in_extra_bytes_from_aligned =
(reinterpret_cast<std::uintptr_t>(in_aligned_begin) % in_datatype_size);
uint32_t in_end_padding_req = (in_datatype_size - in_extra_bytes_from_aligned) % in_datatype_size;
// Bytes after `out_chars_aligned` to the last VectorT-aligned
// address at (or before) `out_begin` + `num_bytes`
uint32_t out_end_aligned{};
if (in_end_padding_req + alignment_offset > num_bytes)
{
out_end_aligned = out_start_aligned;
}
else
{
out_end_aligned = (num_bytes - in_end_padding_req + alignment_offset) / out_datatype_size *
out_datatype_size;
}
VectorT *out_aligned_end = reinterpret_cast<VectorT *>(out_chars_aligned + out_end_aligned);
const char *in_aligned_end = in_ptr + (reinterpret_cast<char *>(out_aligned_end) - out_ptr);
return {out_aligned_begin, out_aligned_end, in_aligned_begin, in_aligned_end};
}
/**
* @brief Cooperatively copies \p num_bytes from \p src to \p dest using vectorized stores of type
* \p VectorT for addresses within [dest, dest + num_bytes) that are aligned to \p VectorT. A
* byte-wise copy is used for byte-ranges that are not aligned to \p VectorT.
*
* @tparam LOGICAL_WARP_SIZE The number of threads cooperaing to copy the data; all threads within
* [0, `LOGICAL_WARP_SIZE`) must invoke this method with the same arguments
* @tparam VectorT The vector type used for vectorized stores (i.e., one of uint4, uint2, uint32_t)
* @tparam ByteOffsetT Type used to index the bytes within the buffers
* @param thread_rank The thread rank within the group that cooperates to copy the data must be
* within [0, `LOGICAL_WARP_SIZE`)
* @param dest Pointer to the memory location to copy to
* @param num_bytes Number of bytes to copy
* @param src Pointer to the memory location to copy from
*/
template <int LOGICAL_WARP_SIZE, typename VectorT, typename ByteOffsetT>
__device__ __forceinline__ void
VectorizedCopy(int32_t thread_rank, void *dest, ByteOffsetT num_bytes, const void *src)
{
char *out_ptr = reinterpret_cast<char *>(dest);
const char *in_ptr = reinterpret_cast<const char *>(src);
// Gets the byte range that can safely be copied using vectorized stores of type VectorT
auto aligned_range = GetAlignedPtrs<VectorT>(src, dest, num_bytes);
// If byte range for which we can use vectorized copies is empty -> use byte-wise copies
if (aligned_range.out_end <= aligned_range.out_begin)
{
for (ByteOffsetT ichar = thread_rank; ichar < num_bytes; ichar += LOGICAL_WARP_SIZE)
{
out_ptr[ichar] = in_ptr[ichar];
}
}
else
{
// Copy bytes in range `[dest, aligned_range.out_begin)`
out_ptr += thread_rank;
in_ptr += thread_rank;
while (out_ptr < reinterpret_cast<char *>(aligned_range.out_begin))
{
*out_ptr = *in_ptr;
out_ptr += LOGICAL_WARP_SIZE;
in_ptr += LOGICAL_WARP_SIZE;
}
// Copy bytes in range `[aligned_range.out_begin, aligned_range.out_end)`
VectorT *aligned_range_begin = aligned_range.out_begin + thread_rank;
const char *in_aligned_begin = aligned_range.in_begin + thread_rank * sizeof(VectorT);
while (aligned_range_begin < aligned_range.out_end)
{
VectorT data_in;
LoadVector(in_aligned_begin, data_in);
*aligned_range_begin = data_in;
in_aligned_begin += sizeof(VectorT) * LOGICAL_WARP_SIZE;
aligned_range_begin += LOGICAL_WARP_SIZE;
}
// Copy bytes in range `[aligned_range.out_end, dest + num_bytes)`.
out_ptr = reinterpret_cast<char *>(aligned_range.out_end) + thread_rank;
in_ptr = aligned_range.in_end + thread_rank;
while (out_ptr < reinterpret_cast<char *>(dest) + num_bytes)
{
*out_ptr = *in_ptr;
out_ptr += LOGICAL_WARP_SIZE;
in_ptr += LOGICAL_WARP_SIZE;
}
}
}
template <bool IsMemcpy,
uint32_t LOGICAL_WARP_SIZE,
typename InputBufferT,
typename OutputBufferT,
typename OffsetT,
typename ::cuda::std::enable_if<IsMemcpy, int>::type = 0>
__device__ __forceinline__ void copy_items(InputBufferT input_buffer,
OutputBufferT output_buffer,
OffsetT num_bytes,
OffsetT offset = 0)
{
VectorizedCopy<LOGICAL_WARP_SIZE, uint4>(threadIdx.x % LOGICAL_WARP_SIZE,
&reinterpret_cast<char *>(output_buffer)[offset],
num_bytes,
&reinterpret_cast<const char *>(input_buffer)[offset]);
}
template <bool IsMemcpy,
uint32_t LOGICAL_WARP_SIZE,
typename InputBufferT,
typename OutputBufferT,
typename OffsetT,
typename ::cuda::std::enable_if<!IsMemcpy, int>::type = 0>
__device__ __forceinline__ void copy_items(InputBufferT input_buffer,
OutputBufferT output_buffer,
OffsetT num_items,
OffsetT offset = 0)
{
output_buffer += offset;
input_buffer += offset;
for (OffsetT i = threadIdx.x % LOGICAL_WARP_SIZE; i < num_items; i += LOGICAL_WARP_SIZE)
{
*(output_buffer + i) = *(input_buffer + i);
}
}
template <bool IsMemcpy,
typename AliasT,
typename InputIt,
typename OffsetT,
typename ::cuda::std::enable_if<IsMemcpy, int>::type = 0>
__device__ __forceinline__ AliasT read_item(InputIt buffer_src, OffsetT offset)
{
return *(reinterpret_cast<const AliasT *>(buffer_src) + offset);
}
template <bool IsMemcpy,
typename AliasT,
typename InputIt,
typename OffsetT,
typename ::cuda::std::enable_if<!IsMemcpy, int>::type = 0>
__device__ __forceinline__ AliasT read_item(InputIt buffer_src, OffsetT offset)
{
return *(buffer_src + offset);
}
template <bool IsMemcpy,
typename AliasT,
typename OutputIt,
typename OffsetT,
typename ::cuda::std::enable_if<IsMemcpy, int>::type = 0>
__device__ __forceinline__ void write_item(OutputIt buffer_dst, OffsetT offset, AliasT value)
{
*(reinterpret_cast<AliasT *>(buffer_dst) + offset) = value;
}
template <bool IsMemcpy,
typename AliasT,
typename OutputIt,
typename OffsetT,
typename ::cuda::std::enable_if<!IsMemcpy, int>::type = 0>
__device__ __forceinline__ void write_item(OutputIt buffer_dst, OffsetT offset, AliasT value)
{
*(buffer_dst + offset) = value;
}
/**
* @brief A helper class that allows threads to maintain multiple counters, where the counter that
* shall be incremented can be addressed dynamically without incurring register spillage.
*
* @tparam NUM_ITEMS The number of counters to allocate
* @tparam MAX_ITEM_VALUE The maximum count that must be supported.
* @tparam PREFER_POW2_BITS Whether the number of bits to dedicate to each counter should be a
* power-of-two. If enabled, this allows replacing integer multiplication with a bit-shift in
* exchange for higher register pressure.
* @tparam BackingUnitT The data type that is used to provide the bits of all the counters that
* shall be allocated.
*/
template <uint32_t NUM_ITEMS,
uint32_t MAX_ITEM_VALUE,
bool PREFER_POW2_BITS,
typename BackingUnitT = uint32_t>
class BitPackedCounter
{
private:
/// The minimum number of bits required to represent all values from [0, MAX_ITEM_VALUE]
static constexpr uint32_t MIN_BITS_PER_ITEM =
(MAX_ITEM_VALUE == 0U) ? 1U : cub::Log2<static_cast<int32_t>(MAX_ITEM_VALUE + 1U)>::VALUE;
/// The number of bits allocated for each item. For pre-Volta, we prefer a power-of-2 here to
/// have the compiler replace costly integer multiplication with bit-shifting.
static constexpr uint32_t BITS_PER_ITEM =
PREFER_POW2_BITS ? (0x01ULL << (cub::Log2<static_cast<int32_t>(MIN_BITS_PER_ITEM)>::VALUE))
: MIN_BITS_PER_ITEM;
/// The number of bits that each backing data type can store
static constexpr uint32_t NUM_BITS_PER_UNIT = sizeof(BackingUnitT) * 8;
/// The number of items that each backing data type can store
static constexpr uint32_t ITEMS_PER_UNIT = NUM_BITS_PER_UNIT / BITS_PER_ITEM;
/// The number of bits the backing data type is actually making use of
static constexpr uint32_t USED_BITS_PER_UNIT = ITEMS_PER_UNIT * BITS_PER_ITEM;
/// The number of backing data types required to store the given number of items
static constexpr uint32_t NUM_TOTAL_UNITS = CUB_QUOTIENT_CEILING(NUM_ITEMS, ITEMS_PER_UNIT);
/// This is the net number of bit-storage provided by each unit (remainder bits are unused)
static constexpr uint32_t UNIT_MASK = (USED_BITS_PER_UNIT >= (8U * sizeof(uint32_t)))
? 0xFFFFFFFF
: (0x01U << USED_BITS_PER_UNIT) - 1;
/// This is the bit-mask for each item
static constexpr uint32_t ITEM_MASK = (BITS_PER_ITEM >= (8U * sizeof(uint32_t)))
? 0xFFFFFFFF
: (0x01U << BITS_PER_ITEM) - 1;
//------------------------------------------------------------------------------
// ACCESSORS
//------------------------------------------------------------------------------
public:
__device__ __forceinline__ uint32_t Get(uint32_t index) const
{
const uint32_t target_offset = index * BITS_PER_ITEM;
uint32_t val = 0;
#pragma unroll
for (uint32_t i = 0; i < NUM_TOTAL_UNITS; ++i)
{
// In case the bit-offset of the counter at <index> is larger than the bit range of the
// current unit, the bit_shift amount will be larger than the bits provided by this unit. As
// C++'s bit-shift has undefined behaviour if the bits being shifted exceed the operand width,
// we use the PTX instruction `shr` to make sure behaviour is well-defined.
// Negative bit-shift amounts wrap around in unsigned integer math and are ultimately clamped.
const uint32_t bit_shift = target_offset - i * USED_BITS_PER_UNIT;
val |= detail::LogicShiftRight(data[i], bit_shift) & ITEM_MASK;
}
return val;
}
__device__ __forceinline__ void Add(uint32_t index, uint32_t value)
{
const uint32_t target_offset = index * BITS_PER_ITEM;
#pragma unroll
for (uint32_t i = 0; i < NUM_TOTAL_UNITS; ++i)
{
// In case the bit-offset of the counter at <index> is larger than the bit range of the
// current unit, the bit_shift amount will be larger than the bits provided by this unit. As
// C++'s bit-shift has undefined behaviour if the bits being shifted exceed the operand width,
// we use the PTX instruction `shl` to make sure behaviour is well-defined.
// Negative bit-shift amounts wrap around in unsigned integer math and are ultimately clamped.
const uint32_t bit_shift = target_offset - i * USED_BITS_PER_UNIT;
data[i] += detail::LogicShiftLeft(value, bit_shift) & UNIT_MASK;
}
}
__device__ BitPackedCounter operator+(const BitPackedCounter &rhs) const
{
BitPackedCounter result;
#pragma unroll
for (uint32_t i = 0; i < NUM_TOTAL_UNITS; ++i)
{
result.data[i] = data[i] + rhs.data[i];
}
return result;
}
//------------------------------------------------------------------------------
// MEMBER VARIABLES
//------------------------------------------------------------------------------
private:
BackingUnitT data[NUM_TOTAL_UNITS] = {};
};
/**
* Parameterizable tuning policy type for AgentBatchMemcpy
*/
template <uint32_t _BLOCK_THREADS,
uint32_t _BUFFERS_PER_THREAD,
uint32_t _TLEV_BYTES_PER_THREAD,
bool _PREFER_POW2_BITS,
uint32_t _BLOCK_LEVEL_TILE_SIZE>
struct AgentBatchMemcpyPolicy
{
/// Threads per thread block
static constexpr uint32_t BLOCK_THREADS = _BLOCK_THREADS;
/// Items per thread (per tile of input)
static constexpr uint32_t BUFFERS_PER_THREAD = _BUFFERS_PER_THREAD;
/// The number of bytes that each thread will work on with each iteration of reading in bytes
/// from one or more
// source-buffers and writing them out to the respective destination-buffers.
static constexpr uint32_t TLEV_BYTES_PER_THREAD = _TLEV_BYTES_PER_THREAD;
/// Whether the BitPackedCounter should prefer allocating a power-of-2 number of bits per
/// counter
static constexpr uint32_t PREFER_POW2_BITS = _PREFER_POW2_BITS;
/// BLEV tile size granularity
static constexpr uint32_t BLOCK_LEVEL_TILE_SIZE = _BLOCK_LEVEL_TILE_SIZE;
};
template <typename AgentMemcpySmallBuffersPolicyT,
typename InputBufferIt,
typename OutputBufferIt,
typename BufferSizeIteratorT,
typename BufferOffsetT,
typename BlevBufferSrcsOutItT,
typename BlevBufferDstsOutItT,
typename BlevBufferSizesOutItT,
typename BlevBufferTileOffsetsOutItT,
typename BlockOffsetT,
typename BLevBufferOffsetTileState,
typename BLevBlockOffsetTileState,
bool IsMemcpy>
class AgentBatchMemcpy
{
private:
//---------------------------------------------------------------------
// CONFIGS / CONSTANTS
//---------------------------------------------------------------------
// Tuning policy-based configurations
static constexpr uint32_t BLOCK_THREADS = AgentMemcpySmallBuffersPolicyT::BLOCK_THREADS;
static constexpr uint32_t BUFFERS_PER_THREAD = AgentMemcpySmallBuffersPolicyT::BUFFERS_PER_THREAD;
static constexpr uint32_t TLEV_BYTES_PER_THREAD =
AgentMemcpySmallBuffersPolicyT::TLEV_BYTES_PER_THREAD;
static constexpr bool PREFER_POW2_BITS = AgentMemcpySmallBuffersPolicyT::PREFER_POW2_BITS;
static constexpr uint32_t BLOCK_LEVEL_TILE_SIZE =
AgentMemcpySmallBuffersPolicyT::BLOCK_LEVEL_TILE_SIZE;
// Derived configs
static constexpr uint32_t BUFFERS_PER_BLOCK = BUFFERS_PER_THREAD * BLOCK_THREADS;
static constexpr uint32_t TLEV_BUFFERS_PER_THREAD = BUFFERS_PER_THREAD;
static constexpr uint32_t BLEV_BUFFERS_PER_THREAD = BUFFERS_PER_THREAD;
static constexpr uint32_t WARP_LEVEL_THRESHOLD = 128;
static constexpr uint32_t BLOCK_LEVEL_THRESHOLD = 8 * 1024;
static constexpr uint32_t BUFFER_STABLE_PARTITION = false;
// Constants
enum : uint32_t
{
TLEV_SIZE_CLASS = 0,
WLEV_SIZE_CLASS,
BLEV_SIZE_CLASS,
NUM_SIZE_CLASSES,
};
//---------------------------------------------------------------------
// TYPE DECLARATIONS
//---------------------------------------------------------------------
/// Internal load/store type. For byte-wise memcpy, a single-byte type
using AliasT = typename ::cuda::std::conditional<
IsMemcpy,
std::iterator_traits<char *>,
std::iterator_traits<cub::detail::value_t<InputBufferIt>>>::type::value_type;
/// Types of the input and output buffers
using InputBufferT = cub::detail::value_t<InputBufferIt>;
using OutputBufferT = cub::detail::value_t<OutputBufferIt>;
/// Type that has to be sufficiently large to hold any of the buffers' sizes.
/// The BufferSizeIteratorT's value type must be convertible to this type.
using BufferSizeT = cub::detail::value_t<BufferSizeIteratorT>;
/// Type used to index into the tile of buffers that this thread block is assigned to.
using BlockBufferOffsetT = uint16_t;
/// Internal type used to index into the bytes of and represent size of a TLEV buffer
using TLevBufferSizeT = uint16_t;
/**
* @brief Helper struct to simplify BlockExchange within a single four-byte word
*/
struct ZippedTLevByteAssignment
{
// The buffer id within this tile
BlockBufferOffsetT tile_buffer_id;
// Byte-offset within that buffer
TLevBufferSizeT buffer_byte_offset;
};
/**
* POD to keep track of <buffer_id, buffer_size> pairs after having partitioned this tile's
* buffers by their size.
*/
struct BufferTuple
{
// Size is only valid (and relevant) for buffers that are use thread-level collaboration
TLevBufferSizeT size;
// The buffer id relativ to this tile (i.e., the buffer id within this tile)
BlockBufferOffsetT buffer_id;
};
// Load buffers in a striped arrangement if we do not want to performa a stable partitioning into
// small, medium, and large buffers, otherwise load them in a blocked arrangement
using BufferLoadT =
BlockLoad<BufferSizeT,
static_cast<int32_t>(BLOCK_THREADS),
static_cast<int32_t>(BUFFERS_PER_THREAD),
BUFFER_STABLE_PARTITION ? BLOCK_LOAD_WARP_TRANSPOSE : BLOCK_LOAD_STRIPED>;
// A vectorized counter that will count the number of buffers that fall into each of the
// size-classes. Where the size class representes the collaboration level that is required to
// process a buffer. The collaboration level being either:
//-> (1) TLEV (thread-level collaboration), requiring one or multiple threads but not a FULL warp
// to collaborate
//-> (2) WLEV (warp-level collaboration), requiring a full warp to collaborate on a buffer
//-> (3) BLEV (block-level collaboration), requiring one or multiple thread blocks to collaborate
// on a buffer */
using VectorizedSizeClassCounterT =
BitPackedCounter<NUM_SIZE_CLASSES, BUFFERS_PER_BLOCK, PREFER_POW2_BITS>;
// Block-level scan used to compute the write offsets
using BlockSizeClassScanT =
cub::BlockScan<VectorizedSizeClassCounterT, static_cast<int32_t>(BLOCK_THREADS)>;
//
using BlockBLevTileCountScanT = cub::BlockScan<BlockOffsetT, static_cast<int32_t>(BLOCK_THREADS)>;
// Block-level run-length decode algorithm to evenly distribute work of all buffers requiring
// thread-level collaboration
using BlockRunLengthDecodeT =
cub::BlockRunLengthDecode<BlockBufferOffsetT,
static_cast<int32_t>(BLOCK_THREADS),
static_cast<int32_t>(TLEV_BUFFERS_PER_THREAD),
static_cast<int32_t>(TLEV_BYTES_PER_THREAD)>;
using BlockExchangeTLevT = cub::BlockExchange<ZippedTLevByteAssignment,
static_cast<int32_t>(BLOCK_THREADS),
static_cast<int32_t>(TLEV_BYTES_PER_THREAD)>;
using BLevBuffScanPrefixCallbackOpT =
TilePrefixCallbackOp<BufferOffsetT, Sum, BLevBufferOffsetTileState>;
using BLevBlockScanPrefixCallbackOpT =
TilePrefixCallbackOp<BlockOffsetT, Sum, BLevBlockOffsetTileState>;
//-----------------------------------------------------------------------------
// SHARED MEMORY DECLARATIONS
//-----------------------------------------------------------------------------
struct _TempStorage
{
union
{
typename BufferLoadT::TempStorage load_storage;
// Stage 1: histogram over the size classes in preparation for partitioning buffers by size
typename BlockSizeClassScanT::TempStorage size_scan_storage;
// Stage 2: Communicate the number ofer buffers requiring block-level collaboration
typename BLevBuffScanPrefixCallbackOpT::TempStorage buffer_scan_callback;
// Stage 3; batch memcpy buffers that require only thread-level collaboration
struct
{
BufferTuple buffers_by_size_class[BUFFERS_PER_BLOCK];
// Stage 3.1: Write buffers requiring block-level collaboration to queue
union
{
struct
{
typename BLevBlockScanPrefixCallbackOpT::TempStorage block_scan_callback;
typename BlockBLevTileCountScanT::TempStorage block_scan_storage;
} blev;
// Stage 3.3: run-length decode & block exchange for tlev
// rld_state needs to be persistent across loop iterations (RunLengthDecode calls) and,
// hence, cannot alias block_exchange_storage
struct
{
typename BlockRunLengthDecodeT::TempStorage rld_state;
typename BlockExchangeTLevT::TempStorage block_exchange_storage;
} tlev;
};
} staged;
};
BufferOffsetT blev_buffer_offset;
};
//-----------------------------------------------------------------------------
// PUBLIC TYPE MEMBERS
//-----------------------------------------------------------------------------
public:
struct TempStorage : Uninitialized<_TempStorage>
{};
//-----------------------------------------------------------------------------
// PRIVATE MEMBER FUNCTIONS
//-----------------------------------------------------------------------------
private:
/// Shared storage reference
_TempStorage &temp_storage;
/**
* @brief Loads this tile's buffers' sizes, without any guards (i.e., out-of-bounds checks)
*/
__device__ __forceinline__ void
LoadBufferSizesFullTile(BufferSizeIteratorT tile_buffer_sizes_it,
BufferSizeT (&buffer_sizes)[BUFFERS_PER_THREAD])
{
BufferLoadT(temp_storage.load_storage).Load(tile_buffer_sizes_it, buffer_sizes);
}
/**
* @brief Loads this tile's buffers' sizes, making sure to read at most \p num_valid items.
*/
__device__ __forceinline__ void
LoadBufferSizesPartialTile(BufferSizeIteratorT tile_buffer_sizes_it,
BufferSizeT (&buffer_sizes)[BUFFERS_PER_THREAD],
BufferOffsetT num_valid)
{
// Out-of-bounds buffer items are initialized to '0', so those buffers will simply be ignored
// later on
constexpr BufferSizeT OOB_DEFAULT_BUFFER_SIZE = 0U;
BufferLoadT(temp_storage.load_storage)
.Load(tile_buffer_sizes_it, buffer_sizes, num_valid, OOB_DEFAULT_BUFFER_SIZE);
}
/**
* @brief Computes the histogram over the number of buffers belonging to each of the three
* size-classes (TLEV, WLEV, BLEV).
*/
__device__ __forceinline__ VectorizedSizeClassCounterT
GetBufferSizeClassHistogram(const BufferSizeT (&buffer_sizes)[BUFFERS_PER_THREAD])
{
VectorizedSizeClassCounterT vectorized_counters{};
#pragma unroll
for (uint32_t i = 0; i < BUFFERS_PER_THREAD; i++)
{
// Whether to increment ANY of the buffer size classes at all
const uint32_t increment = buffer_sizes[i] > 0 ? 1U : 0U;
// Identify the buffer's size class
uint32_t buffer_size_class = 0;
buffer_size_class += buffer_sizes[i] > WARP_LEVEL_THRESHOLD ? 1U : 0U;
buffer_size_class += buffer_sizes[i] > BLOCK_LEVEL_THRESHOLD ? 1U : 0U;
// Increment the count of the respective size class
vectorized_counters.Add(buffer_size_class, increment);
}
return vectorized_counters;
}
/**
* @brief Scatters the buffers into the respective buffer's size-class partition.
*/
__device__ __forceinline__ void
PartitionBuffersBySize(const BufferSizeT (&buffer_sizes)[BUFFERS_PER_THREAD],
VectorizedSizeClassCounterT &vectorized_offsets,
BufferTuple (&buffers_by_size_class)[BUFFERS_PER_BLOCK])
{
// If we intend to perform a stable partitioning, the thread's buffer are in a blocked
// arrangement, otherwise they are in a striped arrangement
BlockBufferOffsetT buffer_id = BUFFER_STABLE_PARTITION ? (BUFFERS_PER_THREAD * threadIdx.x)
: (threadIdx.x);
constexpr BlockBufferOffsetT BUFFER_STRIDE = BUFFER_STABLE_PARTITION
? static_cast<BlockBufferOffsetT>(1)
: static_cast<BlockBufferOffsetT>(BLOCK_THREADS);
#pragma unroll
for (uint32_t i = 0; i < BUFFERS_PER_THREAD; i++)
{
if (buffer_sizes[i] > 0)
{
uint32_t buffer_size_class = 0;
buffer_size_class += buffer_sizes[i] > WARP_LEVEL_THRESHOLD ? 1U : 0U;
buffer_size_class += buffer_sizes[i] > BLOCK_LEVEL_THRESHOLD ? 1U : 0U;
const uint32_t write_offset = vectorized_offsets.Get(buffer_size_class);
buffers_by_size_class[write_offset] = {static_cast<TLevBufferSizeT>(buffer_sizes[i]),
buffer_id};
vectorized_offsets.Add(buffer_size_class, 1U);
}
buffer_id += BUFFER_STRIDE;
}
}
/**
* @brief Read in all the buffers that require block-level collaboration and put them to a queue
* that will get picked up in a separate, subsequent kernel.
*/
__device__ __forceinline__ void EnqueueBLEVBuffers(BufferTuple *buffers_by_size_class,
InputBufferIt tile_buffer_srcs,
OutputBufferIt tile_buffer_dsts,
BufferSizeIteratorT tile_buffer_sizes,
BlockBufferOffsetT num_blev_buffers,
BufferOffsetT tile_buffer_offset,
BufferOffsetT tile_id)
{
BlockOffsetT block_offset[BLEV_BUFFERS_PER_THREAD];
// Read in the BLEV buffer partition (i.e., the buffers that require block-level collaboration)
uint32_t blev_buffer_offset = threadIdx.x * BLEV_BUFFERS_PER_THREAD;
#pragma unroll
for (uint32_t i = 0; i < BLEV_BUFFERS_PER_THREAD; i++)
{
if (blev_buffer_offset < num_blev_buffers)
{
BlockBufferOffsetT tile_buffer_id = buffers_by_size_class[blev_buffer_offset].buffer_id;
block_offset[i] = CUB_QUOTIENT_CEILING(tile_buffer_sizes[tile_buffer_id],
BLOCK_LEVEL_TILE_SIZE);
}
else
{
// Out-of-bounds buffers are assigned a tile count of '0'
block_offset[i] = 0U;
}
blev_buffer_offset++;
}
if (tile_id == 0)
{
BlockOffsetT block_aggregate;
BlockBLevTileCountScanT(temp_storage.staged.blev.block_scan_storage)
.ExclusiveSum(block_offset, block_offset, block_aggregate);
if (threadIdx.x == 0)
{
blev_block_scan_state.SetInclusive(0, block_aggregate);
}
}
else
{
BLevBlockScanPrefixCallbackOpT blev_tile_prefix_op(
blev_block_scan_state,
temp_storage.staged.blev.block_scan_callback,
Sum(),
tile_id);
BlockBLevTileCountScanT(temp_storage.staged.blev.block_scan_storage)
.ExclusiveSum(block_offset, block_offset, blev_tile_prefix_op);
}
CTA_SYNC();
// Read in the BLEV buffer partition (i.e., the buffers that require block-level collaboration)
blev_buffer_offset = threadIdx.x * BLEV_BUFFERS_PER_THREAD;
#pragma unroll
for (uint32_t i = 0; i < BLEV_BUFFERS_PER_THREAD; i++)
{
if (blev_buffer_offset < num_blev_buffers)
{
BlockBufferOffsetT tile_buffer_id = buffers_by_size_class[blev_buffer_offset].buffer_id;
blev_buffer_srcs[tile_buffer_offset + blev_buffer_offset] =
tile_buffer_srcs[tile_buffer_id];
blev_buffer_dsts[tile_buffer_offset + blev_buffer_offset] =
tile_buffer_dsts[tile_buffer_id];
blev_buffer_sizes[tile_buffer_offset + blev_buffer_offset] =
tile_buffer_sizes[tile_buffer_id];
blev_buffer_tile_offsets[tile_buffer_offset + blev_buffer_offset] = block_offset[i];
blev_buffer_offset++;
}
}
}
/**
* @brief Read in all the buffers of this tile that require warp-level collaboration and copy
* their bytes to the corresponding destination buffer
*/
__device__ __forceinline__ void BatchMemcpyWLEVBuffers(BufferTuple *buffers_by_size_class,
InputBufferIt tile_buffer_srcs,
OutputBufferIt tile_buffer_dsts,
BufferSizeIteratorT tile_buffer_sizes,
BlockBufferOffsetT num_wlev_buffers)
{
const int32_t warp_id = threadIdx.x / CUB_PTX_WARP_THREADS;
constexpr uint32_t WARPS_PER_BLOCK = BLOCK_THREADS / CUB_PTX_WARP_THREADS;
for (BlockBufferOffsetT buffer_offset = warp_id; buffer_offset < num_wlev_buffers;
buffer_offset += WARPS_PER_BLOCK)
{
const auto buffer_id = buffers_by_size_class[buffer_offset].buffer_id;
copy_items<IsMemcpy, CUB_PTX_WARP_THREADS, InputBufferT, OutputBufferT, BufferSizeT>(
tile_buffer_srcs[buffer_id],
tile_buffer_dsts[buffer_id],
tile_buffer_sizes[buffer_id]);
}
}
/**
* @brief Read in all the buffers of this tile that require thread-level collaboration and copy
* their bytes to the corresponding destination buffer
*/
__device__ __forceinline__ void BatchMemcpyTLEVBuffers(BufferTuple *buffers_by_size_class,
InputBufferIt tile_buffer_srcs,
OutputBufferIt tile_buffer_dsts,
BlockBufferOffsetT num_tlev_buffers)
{
// Read in the buffers' ids that require thread-level collaboration (where buffer id is the
// buffer within this tile)
BlockBufferOffsetT tlev_buffer_ids[TLEV_BUFFERS_PER_THREAD];
TLevBufferSizeT tlev_buffer_sizes[TLEV_BUFFERS_PER_THREAD];
// Currently we do not go over the TLEV buffers in multiple iterations, so we need to make sure
// we are able to be covered for the case that all our buffers are TLEV buffers
static_assert(TLEV_BUFFERS_PER_THREAD >= BUFFERS_PER_THREAD,
"Unsupported confiugraiton: The number of 'thread-level buffers' must be at "
"least as large as the number of overall buffers being processed by each "
"thread.");
// Read in the TLEV buffer partition (i.e., the buffers that require thread-level collaboration)
uint32_t tlev_buffer_offset = threadIdx.x * TLEV_BUFFERS_PER_THREAD;
// Pre-populate the buffer sizes to 0 (i.e. zero-padding towards the end) to ensure
// out-of-bounds TLEV buffers will not be considered
#pragma unroll
for (uint32_t i = 0; i < TLEV_BUFFERS_PER_THREAD; i++)
{
tlev_buffer_sizes[i] = 0;
}
// Assign TLEV buffers in a blocked arrangement (each thread is assigned consecutive TLEV
// buffers)
#pragma unroll
for (uint32_t i = 0; i < TLEV_BUFFERS_PER_THREAD; i++)
{
if (tlev_buffer_offset < num_tlev_buffers)
{
tlev_buffer_ids[i] = buffers_by_size_class[tlev_buffer_offset].buffer_id;
tlev_buffer_sizes[i] = buffers_by_size_class[tlev_buffer_offset].size;
}
tlev_buffer_offset++;
}
// Evenly distribute all the bytes that have to be copied from all the buffers that require
// thread-level collaboration using BlockRunLengthDecode
uint32_t num_total_tlev_bytes = 0U;
BlockRunLengthDecodeT block_run_length_decode(temp_storage.staged.tlev.rld_state,
tlev_buffer_ids,
tlev_buffer_sizes,
num_total_tlev_bytes);
// Run-length decode the buffers' sizes into a window buffer of limited size. This is repeated
// until we were able to cover all the bytes of TLEV buffers
uint32_t decoded_window_offset = 0U;
while (decoded_window_offset < num_total_tlev_bytes)
{
BlockBufferOffsetT buffer_id[TLEV_BYTES_PER_THREAD];
TLevBufferSizeT buffer_byte_offset[TLEV_BYTES_PER_THREAD];
// Now we have a balanced assignment: buffer_id[i] will hold the tile's buffer id and
// buffer_byte_offset[i] that buffer's byte that this thread supposed to copy
block_run_length_decode.RunLengthDecode(buffer_id, buffer_byte_offset, decoded_window_offset);
// Zip from SoA to AoS
ZippedTLevByteAssignment zipped_byte_assignment[TLEV_BYTES_PER_THREAD];
#pragma unroll
for (int32_t i = 0; i < TLEV_BYTES_PER_THREAD; i++)
{
zipped_byte_assignment[i] = {buffer_id[i], buffer_byte_offset[i]};
}
// Exchange from blocked to striped arrangement for coalesced memory reads and writes
BlockExchangeTLevT(temp_storage.staged.tlev.block_exchange_storage)
.BlockedToStriped(zipped_byte_assignment, zipped_byte_assignment);
// Read in the bytes that this thread is assigned to
constexpr uint32_t WINDOW_SIZE = (TLEV_BYTES_PER_THREAD * BLOCK_THREADS);
const bool is_full_window = decoded_window_offset + WINDOW_SIZE < num_total_tlev_bytes;
if (is_full_window)
{
uint32_t absolute_tlev_byte_offset = decoded_window_offset + threadIdx.x;
AliasT src_byte[TLEV_BYTES_PER_THREAD];
#pragma unroll
for (int32_t i = 0; i < TLEV_BYTES_PER_THREAD; i++)
{
src_byte[i] = read_item<IsMemcpy, AliasT, InputBufferT>(
tile_buffer_srcs[zipped_byte_assignment[i].tile_buffer_id],
zipped_byte_assignment[i].buffer_byte_offset);
absolute_tlev_byte_offset += BLOCK_THREADS;
}
#pragma unroll
for (int32_t i = 0; i < TLEV_BYTES_PER_THREAD; i++)
{
write_item<IsMemcpy, AliasT, OutputBufferT>(
tile_buffer_dsts[zipped_byte_assignment[i].tile_buffer_id],
zipped_byte_assignment[i].buffer_byte_offset,
src_byte[i]);
}
}
else
{
uint32_t absolute_tlev_byte_offset = decoded_window_offset + threadIdx.x;
#pragma unroll
for (int32_t i = 0; i < TLEV_BYTES_PER_THREAD; i++)
{
if (absolute_tlev_byte_offset < num_total_tlev_bytes)
{
const AliasT src_byte = read_item<IsMemcpy, AliasT, InputBufferT>(
tile_buffer_srcs[zipped_byte_assignment[i].tile_buffer_id],
zipped_byte_assignment[i].buffer_byte_offset);
write_item<IsMemcpy, AliasT, OutputBufferT>(
tile_buffer_dsts[zipped_byte_assignment[i].tile_buffer_id],
zipped_byte_assignment[i].buffer_byte_offset,
src_byte);
}
absolute_tlev_byte_offset += BLOCK_THREADS;
}
}
decoded_window_offset += WINDOW_SIZE;
// Ensure all threads finished collaborative BlockExchange so temporary storage can be reused
// with next iteration
CTA_SYNC();
}
}
//-----------------------------------------------------------------------------
// PUBLIC MEMBER FUNCTIONS
//-----------------------------------------------------------------------------
public:
__device__ __forceinline__ void ConsumeTile(BufferOffsetT tile_id)
{
// Offset into this tile's buffers
BufferOffsetT buffer_offset = tile_id * BUFFERS_PER_BLOCK;
// Indicates whether all of this tiles items are within bounds
bool is_full_tile = buffer_offset + BUFFERS_PER_BLOCK < num_buffers;
// Load the buffer sizes of this tile's buffers
BufferSizeIteratorT tile_buffer_sizes_it = buffer_sizes_it + buffer_offset;
BufferSizeT buffer_sizes[BUFFERS_PER_THREAD];
if (is_full_tile)
{
LoadBufferSizesFullTile(tile_buffer_sizes_it, buffer_sizes);
}
else
{
LoadBufferSizesPartialTile(tile_buffer_sizes_it, buffer_sizes, num_buffers - buffer_offset);
}
// Ensure we can repurpose the BlockLoad's temporary storage
CTA_SYNC();
// Count how many buffers fall into each size-class
VectorizedSizeClassCounterT size_class_histogram = GetBufferSizeClassHistogram(buffer_sizes);
// Compute the prefix sum over the histogram
VectorizedSizeClassCounterT size_class_agg = {};
BlockSizeClassScanT(temp_storage.size_scan_storage)
.ExclusiveSum(size_class_histogram, size_class_histogram, size_class_agg);
// Ensure we can repurpose the scan's temporary storage for scattering the buffer ids
CTA_SYNC();
// Factor in the per-size-class counts / offsets
// That is, WLEV buffer offset has to be offset by the TLEV buffer count and BLEV buffer offset
// has to be offset by the TLEV+WLEV buffer count
uint32_t buffer_count = 0U;
for (uint32_t i = 0; i < NUM_SIZE_CLASSES; i++)
{
size_class_histogram.Add(i, buffer_count);
buffer_count += size_class_agg.Get(i);
}
// Signal the number of BLEV buffers we're planning to write out
BufferOffsetT buffer_exclusive_prefix = 0;
if (tile_id == 0)
{
if (threadIdx.x == 0)
{
blev_buffer_scan_state.SetInclusive(tile_id, size_class_agg.Get(BLEV_SIZE_CLASS));
}
buffer_exclusive_prefix = 0;
}
else
{
BLevBuffScanPrefixCallbackOpT blev_buffer_prefix_op(blev_buffer_scan_state,
temp_storage.buffer_scan_callback,
Sum(),
tile_id);
// Signal our partial prefix and wait for the inclusive prefix of previous tiles
if (threadIdx.x < CUB_PTX_WARP_THREADS)
{
buffer_exclusive_prefix = blev_buffer_prefix_op(size_class_agg.Get(BLEV_SIZE_CLASS));
}
}
if (threadIdx.x == 0)
{
temp_storage.blev_buffer_offset = buffer_exclusive_prefix;
}
// Ensure the prefix callback has finished using its temporary storage and that it can be reused
// in the next stage
CTA_SYNC();
// Scatter the buffers into one of the three partitions (TLEV, WLEV, BLEV) depending on their
// size
PartitionBuffersBySize(buffer_sizes,
size_class_histogram,
temp_storage.staged.buffers_by_size_class);
// Ensure all buffers have been partitioned by their size class AND
// ensure that blev_buffer_offset has been written to shared memory
CTA_SYNC();
// TODO: think about prefetching tile_buffer_{srcs,dsts} into shmem
InputBufferIt tile_buffer_srcs = input_buffer_it + buffer_offset;
OutputBufferIt tile_buffer_dsts = output_buffer_it + buffer_offset;
BufferSizeIteratorT tile_buffer_sizes = buffer_sizes_it + buffer_offset;
// Copy block-level buffers
EnqueueBLEVBuffers(
&temp_storage.staged.buffers_by_size_class[size_class_agg.Get(TLEV_SIZE_CLASS) +
size_class_agg.Get(WLEV_SIZE_CLASS)],
tile_buffer_srcs,
tile_buffer_dsts,
tile_buffer_sizes,
size_class_agg.Get(BLEV_SIZE_CLASS),
temp_storage.blev_buffer_offset,
tile_id);
// Ensure we can repurpose the temporary storage required by EnqueueBLEVBuffers
CTA_SYNC();
// Copy warp-level buffers
BatchMemcpyWLEVBuffers(
&temp_storage.staged.buffers_by_size_class[size_class_agg.Get(TLEV_SIZE_CLASS)],
tile_buffer_srcs,
tile_buffer_dsts,
tile_buffer_sizes,
size_class_agg.Get(WLEV_SIZE_CLASS));
// Perform batch memcpy for all the buffers that require thread-level collaboration
uint32_t num_tlev_buffers = size_class_agg.Get(TLEV_SIZE_CLASS);
BatchMemcpyTLEVBuffers(temp_storage.staged.buffers_by_size_class,
tile_buffer_srcs,
tile_buffer_dsts,
num_tlev_buffers);
}
//-----------------------------------------------------------------------------
// CONSTRUCTOR
//-----------------------------------------------------------------------------
__device__ __forceinline__ AgentBatchMemcpy(TempStorage &temp_storage,
InputBufferIt input_buffer_it,
OutputBufferIt output_buffer_it,
BufferSizeIteratorT buffer_sizes_it,
BufferOffsetT num_buffers,
BlevBufferSrcsOutItT blev_buffer_srcs,
BlevBufferDstsOutItT blev_buffer_dsts,
BlevBufferSizesOutItT blev_buffer_sizes,
BlevBufferTileOffsetsOutItT blev_buffer_tile_offsets,
BLevBufferOffsetTileState blev_buffer_scan_state,
BLevBlockOffsetTileState blev_block_scan_state)
: temp_storage(temp_storage.Alias())
, input_buffer_it(input_buffer_it)
, output_buffer_it(output_buffer_it)
, buffer_sizes_it(buffer_sizes_it)
, num_buffers(num_buffers)
, blev_buffer_srcs(blev_buffer_srcs)
, blev_buffer_dsts(blev_buffer_dsts)
, blev_buffer_sizes(blev_buffer_sizes)
, blev_buffer_tile_offsets(blev_buffer_tile_offsets)
, blev_buffer_scan_state(blev_buffer_scan_state)
, blev_block_scan_state(blev_block_scan_state)
{}
private:
// Iterator providing the pointers to the source memory buffers
InputBufferIt input_buffer_it;
// Iterator providing the pointers to the destination memory buffers
OutputBufferIt output_buffer_it;
// Iterator providing the number of bytes to be copied for each pair of buffers
BufferSizeIteratorT buffer_sizes_it;
// The total number of buffer pairs
BufferOffsetT num_buffers;
// Output iterator to which the source pointers of the BLEV buffers are written
BlevBufferSrcsOutItT blev_buffer_srcs;
// Output iterator to which the destination pointers of the BLEV buffers are written
BlevBufferDstsOutItT blev_buffer_dsts;
// Output iterator to which the number of bytes to be copied of the BLEV buffers are written
BlevBufferSizesOutItT blev_buffer_sizes;
// Output iterator to which the mapping of tiles to BLEV buffers is written
BlevBufferTileOffsetsOutItT blev_buffer_tile_offsets;
// The single-pass prefix scan's tile state used for tracking the prefix sum over the number of
// BLEV buffers
BLevBufferOffsetTileState blev_buffer_scan_state;
// The single-pass prefix scan's tile state used for tracking the prefix sum over tiles of BLEV
// buffers
BLevBlockOffsetTileState blev_block_scan_state;
};
} // namespace detail
CUB_NAMESPACE_END
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