Method generate

src/shape_transform_descriptor.cpp:1612–1704

This will generate the operators to apply the shape transformation that is represented by this class. This is the order of operators that will be generated if needed: 1. Reshape/unsqueeze 2. Transpose 3. Broadcast 4. Reshape/squeeze 5. Broadcast This will generate operators backwards starting at 5 and going up. Steps 1-3 are generated from the subdimensions and steps 4-5 are generated with the d

// are generated from the subdimensions and steps 4-5 are generated with the
// dimensions.
std::vector<operation>
shape_transform_descriptor::generate(const std::vector<std::size_t>& input_dims,
                                     bool no_broadcast) const
{
    operation_list result;
    std::vector<dimension> new_dims =
        input_dims.empty() ? dimensions : this->rebase(input_dims).dimensions;
    assert(input_dims.empty() or not new_dims.empty());
    if(no_broadcast)
    {
        for_each_subdimension(new_dims, &flatten_broadcasted_dim);
    }
    else
    {
        // Need broadcast
        if(std::any_of(new_dims.begin(), new_dims.end(), &is_broadcast_dim))
        {
            std::vector<std::size_t> out_lens;
            std::transform(new_dims.begin(),
                           new_dims.end(),
                           std::back_inserter(out_lens),
                           [](const dimension& d) { return d.len(); });
            auto startb     = std::find_if_not(new_dims.begin(), new_dims.end(), &has_no_axes);
            auto trailb     = std::find_if_not(startb, new_dims.end(), &has_axes);
            auto axis       = std::distance(new_dims.begin(), startb);
            auto extra_dims = axis + std::distance(trailb, new_dims.end());
            // Use broadcast instead of multibroadcast
            if(std::all_of(trailb, new_dims.end(), &has_no_axes) and extra_dims > 0 and
               axis < new_dims.size())
            {
                result.push_back(make_op("broadcast", {{"axis", axis}, {"out_lens", out_lens}}));
                new_dims.erase(trailb, new_dims.end());
                new_dims.erase(new_dims.begin(), new_dims.begin() + axis);
            }
            else
            {
                result.push_back(make_op("multibroadcast", {{"out_lens", out_lens}}));
            }
        }
        // If all the dimensions have no axes then there isnt anthing else to do
        // so just clear the new_dims
        if(std::all_of(new_dims.begin(), new_dims.end(), &has_no_axes))
            new_dims.clear();
        // Flatten broadcasted dimensions
        for(auto& d : new_dims)
        {
            if(d.subdimensions.size() != 1)
                continue;
            flatten_broadcasted_dim(d.subdimensions.front());
        }
    }
    // Need squeeze reshape
    if(std::any_of(new_dims.begin(), new_dims.end(), [](const dimension& d) {
           if(d.subdimensions.size() != 1)
               return true;
           return is_broadcast_dim(d);
       }))
    {