struct neighborhood

Declaration

template <int Dims>
struct neighborhood { /* full declaration omitted */ };

Description

Declares a buffer access that extends from the current work item by a symmetric boundary offset, either in all directions in the shape of a bounding box (default), or along each axis separately (without "diagonal" boundary elements). Buffer and kernel dimensions must both match the Dims parameter. This is typically used in stencil applications. For bounding-box neighborhoods, - neighborhood({1}) declares the read for a 1D 3-point stencil, - neighborhood({1, 1}) for a 2D 9-point stencil, and - neighborhood({1, 1, 1}) for a 3D 27-point stencil. For neighborhoods defined along axes only, - neighborhood({1}, neighborhood_shape::along_axes) declares the read for a 1D 3-point stencil, - neighborhood({1, 1}, neighborhood_shape::along_axes) for a 2D 5-point stencil, and - neighborhood({1, 1, 1}, neighborhood_shape::along_axes) for a 3D 7-point stencil. For reads, neighborhood_shape::bounding_box is functionally correct whenever neighborhood_shape::along_axes is, but will lead to unnecessary copies and transfers between diagonal neighbors in 2D-split work assignments when the application does not actually read from those buffer elements.

Declared at: include/range_mapper.h:198

Template Parameters

int Dims

Member Variables

range<Dims> m_extent

neighborhood_shape m_shape

Member Function Overview

• neighborhood(const range<Dims> & extent, neighborhood_shape shape = neighborhood_shape::bounding_box) → explicit
• neighborhood(size_t dim0, size_t dim1) → explicit
• neighborhood(size_t dim0, size_t dim1, size_t dim2) → explicit
• operator()(const chunk<Dims> & chnk) const → detail::region<Dims>
• extend_axis(const detail::box<Dims> & box, int d) const → detail::box<Dims>

Member Functions

¶explicit neighborhood(
    const range<Dims>& extent,
    neighborhood_shape shape =
        neighborhood_shape::bounding_box)

Declared at: include/range_mapper.h:199

Parameters

const range<Dims>& extent

neighborhood_shape shape = neighborhood_shape::bounding_box

---

¶explicit neighborhood(size_t dim0, size_t dim1)

Declared at: include/range_mapper.h:203

Parameters

size_t dim0

size_t dim1

---

¶explicit neighborhood(size_t dim0,
                      size_t dim1,
                      size_t dim2)

Declared at: include/range_mapper.h:208

Parameters

size_t dim0

size_t dim1

size_t dim2

---

¶detail::region<Dims> operator()(
    const chunk<Dims>& chnk) const

Declared at: include/range_mapper.h:212

Parameters

const chunk<Dims>& chnk

---

¶inline detail::box<Dims> extend_axis(
    const detail::box<Dims>& box,
    int d) const

Declared at: include/range_mapper.h:236

Parameters

const detail::box<Dims>& box

int d

---