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Help me make a flowchart on opencl code, I don't quite understand how it should look like.The code performs the min(A+C) operation.

#define _CRT_SECURE_NO_WARNINGS
#define CL_USE_DEPRECATED_OPENCL_1_2_APIS
#include <CL/cl.h>
#include <CL/cl_platform.h>
#include <iostream>
#include <cstdlib>
#include <stdio.h>
 
#define MAX_SOURCE_SIZE (0x100000)
#define LIST_SIZE 128
 
int main(void) {
   int* A = new int[LIST_SIZE];
   int* C = new int[LIST_SIZE];
   int* B = new int[LIST_SIZE];
   srand(time(0));
   for (int i = 0; i < LIST_SIZE; i++) {
       A[i] = (rand() % 200) / 2.;
       C[i] = (rand() % 200) / 2.;
   }
 
   FILE* fp;
   char* source_str;
   size_t source_size;
 
   fp = fopen("kernel.cl", "r");
   if (!fp) {
       fprintf(stderr, "Failed to load kernel.\n");
       exit(1);
   }
   source_str = new char[MAX_SOURCE_SIZE];
   source_size = fread(source_str, 1, MAX_SOURCE_SIZE, fp);
   fclose(fp);
 
   cl_platform_id platform_id = NULL;
   cl_device_id device_id = NULL;
   cl_uint ret_num_devices;
   cl_uint ret_num_platforms;
   cl_int ret = clGetPlatformIDs(1, &platform_id, &ret_num_platforms);
   ret = clGetDeviceIDs(platform_id, CL_DEVICE_TYPE_DEFAULT, 1, &device_id, &ret_num_devices);
 
   
   cl_context context = clCreateContext(NULL, 1, &device_id, NULL, NULL, &ret);
 
  
   cl_command_queue command_queue = clCreateCommandQueueWithProperties(context, device_id, 0, &ret);

   cl_mem a_mem_obj = clCreateBuffer(context, CL_MEM_READ_ONLY, LIST_SIZE * sizeof(int), NULL, &ret);
   cl_mem c_mem_obj = clCreateBuffer(context, CL_MEM_READ_ONLY, LIST_SIZE * sizeof(int), NULL, &ret);
   cl_mem b_mem_obj = clCreateBuffer(context, CL_MEM_WRITE_ONLY, LIST_SIZE * sizeof(int), NULL, &ret);
 
   ret = clEnqueueWriteBuffer(command_queue, a_mem_obj, CL_TRUE, 0, LIST_SIZE * sizeof(int), A, 0, NULL, NULL);
   ret = clEnqueueWriteBuffer(command_queue, c_mem_obj, CL_TRUE, 0, LIST_SIZE * sizeof(int), C, 0, NULL, NULL);
 
   cl_program program = clCreateProgramWithSource(context, 1, (const char**)&source_str, (const size_t*)&source_size, &ret);
 
   ret = clBuildProgram(program, 1, &device_id, NULL, NULL, NULL);
 
   cl_kernel kernel = clCreateKernel(program, "krn", &ret);
 
   ret = clSetKernelArg(kernel, 0, sizeof(cl_mem), (void*)&a_mem_obj);
   ret = clSetKernelArg(kernel, 1, sizeof(cl_mem), (void*)&c_mem_obj);
   ret = clSetKernelArg(kernel, 2, sizeof(cl_mem), (void*)&b_mem_obj);
 
   size_t global_item_size = LIST_SIZE;
   size_t local_item_size = 128;
   ret = clEnqueueNDRangeKernel(command_queue, kernel, 1, NULL, &global_item_size, &local_item_size, 0, NULL, NULL);
 
  
   ret = clEnqueueReadBuffer(command_queue, b_mem_obj, CL_TRUE, 0, LIST_SIZE * sizeof(int), B, 0, NULL, NULL);
 
  
   for (int i = 0; i < LIST_SIZE; i++) {
       printf("%d. sum: %d\n", i, B[i]);
   }
   
   int min = B[0];
   int minIndex = 0;
   for (int i = 0; i < LIST_SIZE; i++) {
       if (B[i] < min) {
           min = B[i];
           minIndex = i;
       }
   }
   printf("\n\n%d. Minimum min(A+C) = %d\n", minIndex, min);
 
   ret = clFlush(command_queue);
   ret = clFinish(command_queue);
   ret = clReleaseKernel(kernel);
   ret = clReleaseProgram(program);
   ret = clReleaseMemObject(a_mem_obj);
   ret = clReleaseMemObject(c_mem_obj);
   ret = clReleaseMemObject(b_mem_obj);
   ret = clReleaseCommandQueue(command_queue);
   ret = clReleaseContext(context);
   delete[] source_str;
   delete[] A;
   delete[] B;
   delete[] C;
   return 0;
}


What I have tried:

I wrote the code, but I don't understand at all what the flowchart should look like
Posted

1 solution

Creating a flowchart for OpenCL code involves representing the logical flow of the program with steps. Note that OpenCL programming typically involves both host (CPU) and device (GPU) code flow. Check the below link as guide and try to build of your code.
https://www.researchgate.net/figure/Programming-flowchart-of-level-set-algorithm-in-OpenCL_fig5_271488596[^]
Further, you can check the '
OpenCL program flow
section in the below link and draw the steps accordingly.OpenCL Programming by Example[^]
 
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