cub/util_temporary_storage.cuh
File members: cub/util_temporary_storage.cuh
/******************************************************************************
* Copyright (c) 2011, Duane Merrill. All rights reserved.
* Copyright (c) 2011-2023, NVIDIA CORPORATION. All rights reserved.
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#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_debug.cuh>
#include <cub/util_namespace.cuh>
CUB_NAMESPACE_BEGIN
#ifndef DOXYGEN_SHOULD_SKIP_THIS // Do not document
template <int ALLOCATIONS>
_CCCL_HOST_DEVICE _CCCL_FORCEINLINE cudaError_t AliasTemporaries(
void* d_temp_storage,
size_t& temp_storage_bytes,
void* (&allocations)[ALLOCATIONS],
const size_t (&allocation_sizes)[ALLOCATIONS])
{
constexpr size_t ALIGN_BYTES = 256;
constexpr size_t ALIGN_MASK = ~(ALIGN_BYTES - 1);
// Compute exclusive prefix sum over allocation requests
size_t allocation_offsets[ALLOCATIONS];
size_t bytes_needed = 0;
for (int i = 0; i < ALLOCATIONS; ++i)
{
const size_t allocation_bytes = (allocation_sizes[i] + ALIGN_BYTES - 1) & ALIGN_MASK;
allocation_offsets[i] = bytes_needed;
bytes_needed += allocation_bytes;
}
bytes_needed += ALIGN_BYTES - 1;
// Check if the caller is simply requesting the size of the storage allocation
if (!d_temp_storage)
{
temp_storage_bytes = bytes_needed;
return cudaSuccess;
}
// Check if enough storage provided
if (temp_storage_bytes < bytes_needed)
{
return CubDebug(cudaErrorInvalidValue);
}
// Alias
d_temp_storage =
reinterpret_cast<void*>((reinterpret_cast<uintptr_t>(d_temp_storage) + ALIGN_BYTES - 1) & ALIGN_MASK);
for (int i = 0; i < ALLOCATIONS; ++i)
{
allocations[i] = static_cast<char*>(d_temp_storage) + allocation_offsets[i];
}
return cudaSuccess;
}
#endif // DOXYGEN_SHOULD_SKIP_THIS
CUB_NAMESPACE_END