Retrieve OpenCL Information on OSX

clinfo.m

//
//  clinfo.m
//  clinfo
//
//  Created by Darcy Liu on 26/08/2017.
//  Copyright © 2017 Darcy Liu. All rights reserved.
//

// clang -fobjc-arc -fmodules clinfo.m -o clinfo

#import <Foundation/Foundation.h>
#import <OpenCL/OpenCL.h>


void print_device_info(cl_device_id device) {
    char cBuffer[1024];
    
    clGetDeviceInfo(device, CL_DEVICE_VENDOR, sizeof(cBuffer), &cBuffer, NULL);
    printf("\t Vendor  : %s\n", cBuffer);
    
    clGetDeviceInfo(device, CL_DRIVER_VERSION, sizeof(cBuffer), &cBuffer, NULL);
    
    printf("\t Version : %s\n", cBuffer);
    
    cl_device_type type;
    clGetDeviceInfo(device, CL_DEVICE_TYPE, sizeof(type), &type, NULL);
    
    switch (type) {
        case CL_DEVICE_TYPE_CPU:
            strcpy(cBuffer, "CPU");
            break;
        case CL_DEVICE_TYPE_GPU:
            strcpy(cBuffer, "GPU");
            break;
        case CL_DEVICE_TYPE_ACCELERATOR:
            strcpy(cBuffer, "Accelerator");
            break;
        case CL_DEVICE_TYPE_CUSTOM:
            strcpy(cBuffer, "Custom");
            break;
        case CL_DEVICE_TYPE_ALL:
            strcpy(cBuffer, "All");
            break;
        default:
            strcpy(cBuffer, "Default");
            break;
    }
    
    printf("\t Type : %s\n", cBuffer);
    
    cl_uint compute_units;
    clGetDeviceInfo(device, CL_DEVICE_MAX_COMPUTE_UNITS, sizeof(compute_units), &compute_units, NULL);
    printf("\t Compute Units : %u\n", compute_units);
    
    size_t workitem_dims;
    clGetDeviceInfo(device, CL_DEVICE_MAX_WORK_ITEM_DIMENSIONS, sizeof(workitem_dims), &workitem_dims, NULL);
    printf("\t Workitem Dims : %zu\n", workitem_dims);
    
    size_t workitem_size[3];
    clGetDeviceInfo(device, CL_DEVICE_MAX_WORK_ITEM_SIZES, sizeof(workitem_size), &workitem_size, NULL);
    printf("\t Workitem Size : %zu / %zu / %zu\n", workitem_size[0], workitem_size[1], workitem_size[2]);
    
    size_t workgroup_size;
    clGetDeviceInfo(device, CL_DEVICE_MAX_WORK_GROUP_SIZE, sizeof(workgroup_size), &workgroup_size, NULL);
    printf("\t Workgroup Size : %zu\n", workgroup_size);
    
    cl_uint clock_frequency;
    clGetDeviceInfo(device, CL_DEVICE_MAX_CLOCK_FREQUENCY, sizeof(clock_frequency), &clock_frequency, NULL);
    printf("\t Clock Frequency : %u MHz\n", clock_frequency);
}

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        char cBuffer[1024];
        cl_uint num_platforms;
        cl_int err = clGetPlatformIDs(0, NULL, &num_platforms);
        
        if (err != CL_SUCCESS) {
            return -1;
        }
        cl_platform_id* clPlatformIDs = (cl_platform_id*)malloc(num_platforms * sizeof(cl_platform_id));
        err = clGetPlatformIDs(num_platforms, clPlatformIDs, NULL);
        
        if (err != CL_SUCCESS) {
            return -1;
        }
        for (int i=0; i < num_platforms; i++) {
            err = clGetPlatformInfo (clPlatformIDs[i], CL_PLATFORM_NAME, 1024, &cBuffer, NULL);
            if (err != CL_SUCCESS) {
                continue;
            }
            printf("Platform Name: %s\n", cBuffer);
            
            cl_uint ciDeviceCount;
            
            err = clGetDeviceIDs(clPlatformIDs[i], CL_DEVICE_TYPE_ALL, 0, NULL, &ciDeviceCount);
            
            if (err != CL_SUCCESS) {
                continue;
            }
            cl_device_id *devices = (cl_device_id*)malloc(sizeof(cl_device_id) * ciDeviceCount);
            err = clGetDeviceIDs (clPlatformIDs[i], CL_DEVICE_TYPE_ALL, ciDeviceCount, devices, &ciDeviceCount);
            if (err != CL_SUCCESS) {
                continue;
            }
            printf("OpenCL Device Info: %u devices found.\n",ciDeviceCount);
            
            for(int j=0; j<ciDeviceCount; j++) {
                cl_device_id device = devices[j];
                err = clGetDeviceInfo(device, CL_DEVICE_NAME, sizeof(cBuffer), &cBuffer, NULL);
                if (err != CL_SUCCESS) {
                    continue;
                }
                printf("\nDevice %d: %s\n", j, cBuffer);
                print_device_info(device);
            }
        }
    }
    return 0;
}