I have been working on an c/c++ OpenCL solution for the past few weeks now. For my solution, I need to pass a class from my CPU(Host) to GPU(Device). When I try to pass the class as an argument it gives an error "Unknown Type-Identifier Class". My doubt whether OpenCL on Intel Platform does it allow us to pass a class to kernel or any work around is available for it. In CUDA I have seen some examples and it works perfectly fine for the platform. However, with respect to OpenCL I am not able to find any references and No examples related to this query. I would be really thankful to any help with regards to this issue. I have posted the same question on Intel website but to no avail. If someone would be kind enough to help me understand where I am going wrong or how I should proceed with this I would be really thankful to you.
//HOST SIDE CODE
#include<stdio.h>
#include<iostream>
#include"CL/cl.h"
class test
{
public:
cl_int a;
cl_char b;
};
int main()
{
test *tempstruct = new test;
cl_platform_id platfrom_id;
cl_device_id device_id; // compute device id
cl_context context; // compute context
cl_command_queue commands; // compute command queue
cl_program program; // compute program
cl_kernel kernel; // compute kernel
int err;
err = clGetPlatformIDs(1, &platfrom_id, NULL);
if (err != CL_SUCCESS)
{
printf("Error: Failed to create a platfrom group!\n");
return -1;
}
err = clGetDeviceIDs(platfrom_id, CL_DEVICE_TYPE_GPU, 1, &device_id, NULL);
if (err != CL_SUCCESS)
{
printf("Error: Failed to create a device group!\n");
return -1;
}
context = clCreateContext(0, 1, &device_id, NULL, NULL, NULL);
if (!context)
{
printf("Error: Failed to create a compute context!\n");
return -1;
}
commands = clCreateCommandQueue(context, device_id, 0, NULL);
if (!commands)
{
printf("Error: Failed to create a command commands!\n");
return -1;
}
#define MAX_SOURCE_SIZE (0x100000)
FILE *fp, *fp1;
char filename[] = "Template.cl";
fp = fopen(filename, "r");
if (fp == NULL)
{
printf("\n file not found \n");
return -1;
}
char * source_str = (char*)malloc(MAX_SOURCE_SIZE);
size_t size = fread(source_str, 1, MAX_SOURCE_SIZE, fp);
fclose(fp);
cl_mem classobj = clCreateBuffer(context, CL_MEM_USE_HOST_PTR, sizeof(tempstruct), &tempstruct, &err);
if (err != CL_SUCCESS)
{
printf("Error: Failed to allocate device memory!\n");
return -1;
}
program = clCreateProgramWithSource(context, 1, (const char **)& source_str, (const size_t *)&size, &err);
if (!program)
{
printf("Error: Failed to create program with source!\n");
return -1;
}
err = clBuildProgram(program, 1, &device_id, NULL, NULL, NULL);
if (err != CL_SUCCESS)
{
printf("Error: Failed to build program executable!\n");
return -1;
}
test *resptr = (test *)clEnqueueMapBuffer(commands, classobj, CL_TRUE, CL_MAP_WRITE, NULL, sizeof(test), NULL, NULL, NULL, &err);
// INITIALISATION OF CLASS
tempstruct->a = 10;
if (!resptr)
{
printf("Error: Failed to create enqueuemapbuffer!\n");
return -1;
}
err = clEnqueueUnmapMemObject(commands, classobj, resptr, 0, NULL, NULL);
if (err != CL_SUCCESS)
{
printf("Error: Failed to write to source array!\n");
return -1;
}
kernel = clCreateKernel(program, "CLASS", &err);
if (err != CL_SUCCESS)
{
printf("Error: Failed to create compute kernel!\n");
return -1;
}
err = clSetKernelArg(kernel, 0, sizeof(cl_mem), &classobj);
if (err != CL_SUCCESS)
{
printf("Error: Failed to set kernel arguments! %d\n", err);
return -1;
}
size_t globalsize = 1;
size_t local = 1;
err = clEnqueueNDRangeKernel(commands, kernel, 1, NULL, &globalsize, &local, 0, NULL, NULL);
if (err)
{
printf("Error: Failed to execute nd range!\n");
return -1;
}
test *resptr1 = (test *)clEnqueueMapBuffer(commands, classobj, CL_TRUE, CL_MAP_READ, NULL, sizeof(test), NULL, NULL, NULL, &err);
err = clEnqueueUnmapMemObject(commands, classobj, resptr1, 0, NULL, NULL);
if (err != CL_SUCCESS)
{
printf("Error: Failed to read output array! %d\n", err);
return -1;
}
// again i am printing the class value
printf("\n in cpu side = %d\n", tempstruct->a);
}
//HOST END
//DEVICE SIDE(KERNEL CODE)
// filename : Template.cl
class test
{
public:
cl_int a;
cl_char b;
};
__kernel void CLASS(__global test *inclass )
{
inclass->a = 10;
printf("\n in kernel side = %d \n",inclass->a);
}
//KERNEL END
ERRORS:
I am facing these all errors at kernel side only
1) Error Tempalte.CL unknown type name 'test'
2) Error Tempalte.CL expected ';' after top level declarator
3) Error Tempalte.CL program scope variables are required to be declared in constant address space
4) Error Tempalte.CL unknown type name 'class'
QUERY:
Q)My main Question is How to Pass a CLASS to kernel in Intel architecture
* I have successfully passed class to kernel in AMD. whenever I tried with same code in Intel side it shows the above four errors.
* Is there any alternative method to pass class to kernel in Intel or is it possible to pass class to kernel in Intel architecture ?
