Intel® FPGA SDK for OpenCL™ Standard Edition: Programming Guide

ID 683342
Date 4/22/2019
Public
Document Table of Contents
Give Feedback

6.2.3. Creating a Pipe Object in Your Host Application

To implement OpenCL™ pipes in your kernel, you must create Intel® FPGA SDK for OpenCL™ -specific pipe objects in your host application.

An SDK-specific pipe object is not a true OpenCL pipe object as described in the OpenCL Specification version 2.0. This implementation allows you to migrate away from Intel® FPGA products with a conformant solution. The SDK-specific pipe object is a memory object (cl_mem); however, the host does not allocate any memory for the pipe itself.

The following clCreatePipe host API creates a pipe object:

cl_mem clCreatePipe(cl_context context,
                    cl_mem_flags flags,
                    cl_uint pipe_packet_size,
                    cl_uint pipe_max_packets,
                    const cl_pipe_properties *properties,
                    cl_int *errcode_ret)

For more information on the clCreatePipe host API function, refer to section 5.4.1 of the OpenCL Specification version 2.0.

Below is an example syntax of the clCreatePipe host API function:

cl_int status;
cl_mem c0_pipe = clCreatePipe(context,
                              0,
                              sizeof(int),
                              1,
                              NULL,
                              &status);
status = clSetKernelArg(kernel, 1, sizeof(cl_mem), &c0_pipe);
CAUTION:
The SDK does not support dynamic channel assignment at runtime. The SDK statically links the pipes during compilation based on matching names.