arm_compute::helpers::tensor_transform Namespace Reference

Functions
int	calculate_stride_on_index (int index, Coordinates strides)
	Computes stride of a given index. More...
int	calculate_start_on_index (TensorShape input_shape, int index, Coordinates starts, Coordinates strides, int32_t begin_mask)
	Computes absolute start position of a given index for a strided slice operation. More...
int	calculate_end_on_index (TensorShape input_shape, int index, int start_on_index, Coordinates ends, Coordinates strides, int32_t end_mask=0, int32_t shrink_axis_mask=0)
	Returns the absolute end position of a given index for a strided slice operation. More...
std::tuple< Coordinates, Coordinates, Coordinates >	calculate_strided_slice_coords (TensorShape input_shape, Coordinates starts, Coordinates ends, Coordinates strides, int32_t begin_mask=0, int32_t end_mask=0, int32_t shrink_axis_mask=0)
	Calculate start, end and stride coordinates for a strided slice. More...
TensorShape	compute_strided_slice_output_shape (TensorShape input_shape, Coordinates starts, Coordinates ends, Coordinates strides, int32_t begin_mask=0, int32_t end_mask=0, int32_t shrink_axis_mask=0, bool return_unshrinked=false)
	Computes output shape of strided slice. More...
int32_t	construct_slice_end_mask (Coordinates ends)
	Constructs end mask in case we want to perform a slice operation using the strided slice interface. More...

Function Documentation

calculate_end_on_index()

int calculate_end_on_index	(	TensorShape	input_shape,
		int	index,
		int	start_on_index,
		Coordinates	ends,
		Coordinates	strides,
		int32_t	end_mask = 0,
		int32_t	shrink_axis_mask = 0
	)

Returns the absolute end position of a given index for a strided slice operation.

Parameters

[in]	input_shape	Input tensor shape
[in]	index	Index of tensor to calculate absolute start position
[in]	start_on_index	Absolute start coordinate for given index
[in]	ends	End coordinates
[in]	strides	Slice strides
[in]	end_mask	(Optional) If the ith bit of end_mask is set, end[i] is ignored and the fullest possible range in that dimension is used instead.
[in]	shrink_axis_mask	(Optional) If the ith bit of shrink_axis_mask is set, it implies that the ith specification shrinks the dimensionality by 1. A slice of size 1 starting from starts[i] in the dimension must be preserved.

Returns

Absolute end position of a given index

Definition at line 72 of file tensor_transform.cpp.

References calculate_stride_on_index(), arm_compute::utility::clamp(), arm_compute::helpers::bit_ops::is_bit_set(), arm_compute::support::cpp11::lowest(), and Dimensions< T >::num_dimensions().

Referenced by calculate_strided_slice_coords(), and compute_strided_slice_output_shape().

{
    // Early exit
    if(index >= static_cast<int>(ends.num_dimensions()))
    {
        return input_shape[index];
    }

    const int  stride      = calculate_stride_on_index(index, strides);
    const bool shrink_axis = arm_compute::helpers::bit_ops::is_bit_set(shrink_axis_mask, index);

    // Calculate start
    int stop = ends[index];

    // Shrink dimension
    if(shrink_axis)
    {
        if(start_on_index == std::numeric_limits<int>::max())
        {
            stop = start_on_index;
        }
        else
        {
            stop = start_on_index + 1;
        }
    }

    // Reset in case of begin mask present
    if(arm_compute::helpers::bit_ops::is_bit_set(end_mask, index) && !shrink_axis)
    {
        stop = (stride > 0) ? std::numeric_limits<int>::max() : std::numeric_limits<int>::lowest();
    }

    // Account negative end points
    const int dim_size = input_shape[index];
    if(stop < 0)
    {
        stop += dim_size;
    }

    // Final clamp
    stop = (stride > 0) ? utility::clamp(stop, 0, dim_size) : utility::clamp(stop, -1, dim_size - 1);

    return stop;
}

calculate_start_on_index()

int calculate_start_on_index	(	TensorShape	input_shape,
		int	index,
		Coordinates	starts,
		Coordinates	strides,
		int32_t	begin_mask
	)

Computes absolute start position of a given index for a strided slice operation.

Parameters

[in]	input_shape	Input tensor shape
[in]	index	Index of tensor to calculate absolute start position
[in]	starts	Start coordinates
[in]	strides	Slice strides
[in]	begin_mask	(Optional) If the ith bit of begin_mask is set, starts[i] is ignored and the fullest possible range in that dimension is used instead.

Returns

Absolute start position of a given index

Definition at line 39 of file tensor_transform.cpp.

References calculate_stride_on_index(), arm_compute::utility::clamp(), arm_compute::helpers::bit_ops::is_bit_set(), arm_compute::support::cpp11::lowest(), and Dimensions< T >::num_dimensions().

Referenced by calculate_strided_slice_coords(), and compute_strided_slice_output_shape().

{
    // Early exit
    if(index >= static_cast<int>(starts.num_dimensions()))
    {
        return 0;
    }

    // Get stride
    const int stride = calculate_stride_on_index(index, strides);

    // Calculate start
    int start = starts[index];

    // Reset in case of begin mask present
    if(arm_compute::helpers::bit_ops::is_bit_set(begin_mask, index))
    {
        start = stride > 0 ? std::numeric_limits<int>::lowest() : std::numeric_limits<int>::max();
    }

    // Account negative start points
    const int dim_size = input_shape[index];
    if(start < 0)
    {
        start += dim_size;
    }

    // Final clamp
    start = utility::clamp(start, 0, dim_size - 1);

    return start;
}

calculate_stride_on_index()

int calculate_stride_on_index	(	int	index,
		Coordinates	strides
	)

Computes stride of a given index.

Parameters

[in]	index	Index of tensor to calculate absolute start position
[in]	strides	Slice strides

Returns

Stride at a given index

Definition at line 34 of file tensor_transform.cpp.

References Dimensions< T >::num_dimensions().

Referenced by calculate_end_on_index(), calculate_start_on_index(), calculate_strided_slice_coords(), and compute_strided_slice_output_shape().

{
    return index >= static_cast<int>(strides.num_dimensions()) ? 1 : strides[index];
}

calculate_strided_slice_coords()

std::tuple< Coordinates, Coordinates, Coordinates > calculate_strided_slice_coords	(	TensorShape	input_shape,
		Coordinates	starts,
		Coordinates	ends,
		Coordinates	strides,
		int32_t	begin_mask = 0,
		int32_t	end_mask = 0,
		int32_t	shrink_axis_mask = 0
	)

Calculate start, end and stride coordinates for a strided slice.

Parameters

[in]	input_shape	Input tensor shape
[in]	starts	Start coordinates
[in]	ends	End coordinates
[in]	strides	Slice strides
[in]	begin_mask	(Optional) If the ith bit of begin_mask is set, starts[i] is ignored and the fullest possible range in that dimension is used instead.
[in]	end_mask	(Optional) If the ith bit of end_mask is set, end[i] is ignored and the fullest possible range in that dimension is used instead.
[in]	shrink_axis_mask	(Optional) If the ith bit of shrink_axis_mask is set, it implies that the ith specification shrinks the dimensionality by 1. A slice of size 1 starting from starts[i] in the dimension must be preserved.

Returns

A tuple with <Start,End,Strides>

Definition at line 120 of file tensor_transform.cpp.

References calculate_end_on_index(), calculate_start_on_index(), calculate_stride_on_index(), and Dimensions< T >::num_dimensions().

Referenced by CLStridedSliceKernel::configure(), NEStridedSliceKernel::configure(), and arm_compute::test::validation::reference::strided_slice().

{
    Coordinates starts_abs{};
    Coordinates ends_abs{};
    Coordinates final_strides{};

    for(unsigned int i = 0; i < input_shape.num_dimensions(); ++i)
    {
        const int start_i = calculate_start_on_index(input_shape, i, starts, strides, begin_mask);
        starts_abs.set(i, start_i);
        ends_abs.set(i, calculate_end_on_index(input_shape, i, start_i, ends, strides, end_mask, shrink_axis_mask));
        final_strides.set(i, calculate_stride_on_index(i, strides));
    }

    return std::make_tuple(starts_abs, ends_abs, final_strides);
}

compute_strided_slice_output_shape()

TensorShape compute_strided_slice_output_shape	(	TensorShape	input_shape,
		Coordinates	starts,
		Coordinates	ends,
		Coordinates	strides,
		int32_t	begin_mask = 0,
		int32_t	end_mask = 0,
		int32_t	shrink_axis_mask = 0,
		bool	return_unshrinked = false
	)

Computes output shape of strided slice.

Warning

Starts and ends must be non-negative

Starts, ends and final strides should have the same dimensions as the input shape

Parameters

[in]	input_shape	Input tensor shape
[in]	starts	Absolute start coordinates
[in]	ends	Absolute end coordinates
[in]	strides	Slice strides
[in]	begin_mask	(Optional) If the ith bit of begin_mask is set, starts[i] is ignored and the fullest possible range in that dimension is used instead.
[in]	end_mask	(Optional) If the ith bit of end_mask is set, end[i] is ignored and the fullest possible range in that dimension is used instead.
[in]	shrink_axis_mask	(Optional) If the ith bit of shrink_axis_mask is set, it implies that the ith specification shrinks the dimensionality by 1. A slice of size 1 starting from starts[i] in the dimension must be preserved.
[in]	return_unshrinked	(Optional) Returns un-shrinked shape

Returns

The output tensor shape

Definition at line 139 of file tensor_transform.cpp.

References calculate_end_on_index(), calculate_start_on_index(), calculate_stride_on_index(), arm_compute::mlgo::parser::end(), arm_compute::helpers::bit_ops::is_bit_set(), Dimensions< T >::num_dimensions(), arm_compute::test::validation::output_shape, arm_compute::test::validation::reference::range(), and TensorShape::set().

Referenced by StridedSliceLayerNode::compute_output_descriptor(), arm_compute::misc::shape_calculator::compute_slice_shape(), arm_compute::misc::shape_calculator::compute_strided_slice_shape(), and arm_compute::test::validation::reference::strided_slice().

{
    unsigned int index = 0;

    TensorShape output_shape;
    for(unsigned int i = 0; i < input_shape.num_dimensions(); ++i)
    {
        const int stride = calculate_stride_on_index(index, strides);
        const int start  = calculate_start_on_index(input_shape, i, starts, strides, begin_mask);
        const int end    = calculate_end_on_index(input_shape, i, start, ends, strides, end_mask, shrink_axis_mask);
        const int range  = end - start;

        const bool is_shrink = arm_compute::helpers::bit_ops::is_bit_set(shrink_axis_mask, i);
        if(return_unshrinked || !is_shrink)
        {
            if((range == 0) ||               // Zero range
               (range < 0 && stride >= 0) || // Negative range with positive stride
               (range > 0 && stride <= 0))   // Positive range with negative stride
            {
                output_shape.set(index, 0);
                return output_shape;
            }
            else
            {
                int dim = range / stride + (range % stride != 0 ? 1 : 0);
                output_shape.set(index++, dim);
            }
        }
    }
    return output_shape;
}

construct_slice_end_mask()

int32_t construct_slice_end_mask

(

Coordinates

ends

)

Constructs end mask in case we want to perform a slice operation using the strided slice interface.

Note

Ends are inclusive in slice operations that is why construction an end mask is needed

Parameters

[in]

ends

End coordinates

Returns

End mask

Definition at line 172 of file tensor_transform.cpp.

References Dimensions< T >::num_dimensions().

Referenced by arm_compute::misc::shape_calculator::compute_slice_shape(), NESlice::configure(), CLSlice::configure(), NESlice::validate(), and CLSlice::validate().

{
    // Create end mask
    int32_t end_mask = 0;
    for(unsigned int i = 0; i < ends.num_dimensions(); ++i)
    {
        if(ends[i] < 0)
        {
            end_mask |= 1 << i;
        }
    }

    return end_mask;
}