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cutlass/cutlass/tensor_ref.h
2018-05-16 11:44:56 -07:00

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5.2 KiB
C++

/***************************************************************************************************
* Copyright (c) 2017-2018, 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 TOR (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
\brief Defines a structure containing strides, bounds, and a pointer to tensor data.
*/
#pragma once
#include <typeinfo>
#include <cutlass/coord.h>
#include <cutlass/cutlass.h>
#include <cutlass/vector.h>
namespace cutlass {
////////////////////////////////////////////////////////////////////////////////////////////////////
/// Structure modeling a pointer and stride into a tensor
template <typename Storage_, int Rank_>
class TensorRef {
public:
/// Data type of individual access
typedef Storage_ Storage;
/// Rank of tensor
static int const Rank = Rank_;
private:
//
// Data members
//
/// Pointer to storage element
Storage* ptr_;
/// Stride information
Coord<Rank> stride_;
public:
//
// Methods
//
/// Default ctor
CUTLASS_HOST_DEVICE
TensorRef() : ptr_(nullptr) {}
/// Constructs from a pointer, size, and stride
CUTLASS_HOST_DEVICE
TensorRef(Storage* ptr, Coord<Rank> stride) : ptr_(ptr), stride_(stride) {}
/// Updates the pointer, stride, and location within a TensorRef
CUTLASS_HOST_DEVICE
void reset(Storage* ptr = nullptr, Coord<Rank> stride = Coord<Rank>(0)) {
ptr_ = ptr;
stride_ = stride;
}
/// Conversion function
template <typename T>
TensorRef<T, Rank> convert() {
Coord<Rank> converted_stride;
for (int i = 0; i < Rank - 1; ++i) {
converted_stride[i] = stride_[i] * Extent<Storage>::kValue / Extent<T>::kValue;
}
converted_stride[Rank - 1] = stride_[Rank - 1];
return TensorRef<T, Rank>(reinterpret_cast<T*>(ptr_), converted_stride);
}
/// Returns true if the TensorRef may be safely accessed
CUTLASS_HOST_DEVICE
bool good() const { return ptr_ != nullptr; }
/// Returns the pointer to referenced data
CUTLASS_HOST_DEVICE
Storage* data() const { return ptr_; }
/// Returns the stride of the tensor
CUTLASS_HOST_DEVICE
Coord<Rank> const& stride() const { return stride_; }
/// Returns the stride of the tensor in the given dimension
CUTLASS_HOST_DEVICE
int const& stride(int dim) const { return stride_.at(dim); }
/// Returns the maximum stride element as the 'leading dimension'
CUTLASS_HOST_DEVICE
int leading_dim() const { return __NV_STD_MAX(stride_[1], stride_[2]); }
/// Computes the offset of an index from the origin of the tensor
CUTLASS_HOST_DEVICE
long long offset(Coord<Rank> const& coord) const {
return stride_.template dot<long long>(coord);
}
/// Returns a reference to the element at a given Coord
CUTLASS_HOST_DEVICE
Storage& at(Coord<Rank> const& coord) const { return ptr_[offset(coord)]; }
/// Element-wise accessor
Storage& operator[](Coord<Rank> const& coord) const { return at(coord); }
/// Returns a reference to the element at a given Coord
CUTLASS_HOST_DEVICE
Storage& at(int idx) const { return ptr_[idx]; }
/// Element-wise accessor
Storage& operator[](int idx) const { return at(idx); }
/// Adds an offset to the pointer
CUTLASS_HOST_DEVICE
TensorRef& advance(Coord<Rank> const& b) {
ptr_ += offset(b);
return *this;
}
/// Returns a TensorRef offset by a given amount
CUTLASS_HOST_DEVICE
TensorRef operator+(Coord<Rank> const& b) const { return TensorRef(ptr_ + offset(b), stride_); }
/// Returns a TensorRef offset by a given amount
CUTLASS_HOST_DEVICE
TensorRef operator-(Coord<Rank> const& b) const { return TensorRef(ptr_ - offset(b), stride_); }
};
////////////////////////////////////////////////////////////////////////////////////////////////////
} // namespace cutlass