The private address space is a memory segment that can only be accessed by one work item. Variables that are not shareable among work items are allocated in the private address space, and it is the default address space for most variables, in particular variables with automatic storage duration.
kernel void foo(...)
private int i;
For more information, see the OpenCL C Specification
This page is extracted from the OpenCL C Specification. Fixes and changes should be made to the Specification, not directly.