Intel® C++ Compiler 18.0 Developer Guide and Reference

Functions to Get Hardware Thread Coordinates

Gets the current hardware thread coordinates in the kernel's thread group space. This topic only applies when targeting Intel® Graphics Technology.

Syntax

i32 _gfx_gpgpu_group_count(i32 dim);

i32 _gfx_gpgpu_group_id(i32 dim);

i32 _gfx_gpgpu_local_size(i32 dim);

i32 _gfx_gpgpu_local_id(i32 dim);

Parameters

dim

_gfx_gpgpu_group_count, _gfx_gpgpu_group_id

A dimension in the 2d space of thread groups.

_gfx_gpgpu_local_size, _gfx_gpgpu_local_id

A dimension in the 2d space of threads in a thread group.

Description

These functions get information about a thread group space. A thread group space is 2-dimensional, with a 2-level hierarchy:

The following table shows the information each function gets:

Function

Description

_gfx_gpgpu_group_count

Gets the number of threads groups along a dimension.

_gfx_gpgpu_local_size

Gets the number of threads along a dimension within a thread group.

_gfx_gpgpu_group_id

_gfx_gpgpu_local_id

Gets the coordinates for the current hardware thread in the thread space or thread group space created for the calling kernel.

Return Values

Function: _gfx_gpgpu_group_count

Returns the number of thread groups along the given dimension of a 2-dimensional target thread group space.

Function:_gfx_gpgpu_group_id

Returns the current thread group's coordinate along the given dimension of a 2-dimensional target thread group space.

Function:_gfx_gpgpu_local_size

Returns the number of threads along the given dimension of a 2-dimensional target thread group.

Function:_gfx_gpgpu_local_id

Returns the current thread's coordinates along the given dimension of a 2-dimensional target thread group.