tensor_layout.h

#ifndef TENSOR_LAYOUT_H
#define TENSOR_LAYOUT_H
 
#include <array>
#include <cstdlib>
 
#include "nforge/core/tensor_shape.h"
 
#define MAX_DIMS 8
 
struct TensorLayout {
    std::array<size_t, MAX_DIMS> shape;
 
    std::array<size_t, MAX_DIMS> strides;
 
    size_t offset = 0;
 
    size_t rank = 0;
 
    TensorLayout() : shape{}, strides{} {}
 
    TensorLayout(const Tensor::Shape& _shape);
 
    TensorLayout(const Tensor::Shape& _shape, const std::vector<size_t>& _strides);
 
    TensorLayout(const Tensor::Shape& _shape, const std::vector<size_t>& _strides, size_t _offset);
 
    TensorLayout(std::array<size_t, MAX_DIMS> _shape, std::array<size_t, MAX_DIMS> _strides,
                 size_t _offset, size_t _rank);
 
    bool operator==(const TensorLayout& rhs) const;
 
    bool operator!=(const TensorLayout& rhs) const;
};
 
static inline size_t physicalOffset(size_t linear, const TensorLayout& L) {
    size_t off = L.offset;
    for (int d = L.rank - 1; d >= 0; d--) {
        std::lldiv_t results = std::lldiv((long long)linear, (long long)L.shape[d]);
 
        linear = results.quot;
        off += results.rem * L.strides[d];
    }
    return off;
}
 
#endif  // TENSOR_LAYOUT_H