List OpenCL devices on the system using OpenCL C++ Wrapper.

cpp_wrapper_fix.txt

On Mac OS X 10.9 Maverics I couldn't get C++ OpenCL code run. I guess OpenCL on Mac OS X doens't have C++ Wrapper, so I manually added the wrapper header to fix the issue. I followed the steps below to make it work.

- Download cl.hpp from http://www.khronos.org/registry/cl/api/1.1/cl.hpp

- Move the downloaded cl.hpp file inside /System/Library/Frameworks/OpenCL.framework/Headers/ directory.

- When including in C++ add #include <OpenCL/cl.hpp> instead of #include <OpenCL/opencl.h>

device_query.cpp

#include <iostream>  

#define __NO_STD_VECTOR // Use cl::vector instead of STL version
#define __CL_ENABLE_EXCEPTIONS

#ifdef __APPLE__
//#include <OpenCL/opencl.h>
#include <OpenCL/cl.hpp> /* read cpp_wrapper_fix.txt */
#else
#include <CL/cl.hpp>
#endif


int main(int, char**) {  
    cl::vector<cl::Platform> platforms;  
    cl::Platform::get(&platforms);  

    int platform_id = 0;
    int device_id = 0;

    std::cout << "Number of Platforms: " << platforms.size() << std::endl;

    for(cl::vector<cl::Platform>::iterator it = platforms.begin(); it != platforms.end(); ++it){
        cl::Platform platform(*it);

        std::cout << "Platform ID: " << platform_id++ << std::endl;  
        std::cout << "Platform Name: " << platform.getInfo<CL_PLATFORM_NAME>() << std::endl;  
        std::cout << "Platform Vendor: " << platform.getInfo<CL_PLATFORM_VENDOR>() << std::endl;  

        cl::vector<cl::Device> devices;  
        platform.getDevices(CL_DEVICE_TYPE_GPU | CL_DEVICE_TYPE_CPU, &devices);  

        for(cl::vector<cl::Device>::iterator it2 = devices.begin(); it2 != devices.end(); ++it2){
            cl::Device device(*it2);

            std::cout << "\tDevice " << device_id++ << ": " << std::endl;
            std::cout << "\t\tDevice Name: " << device.getInfo<CL_DEVICE_NAME>() << std::endl;  
            std::cout << "\t\tDevice Type: " << device.getInfo<CL_DEVICE_TYPE>();
            std::cout << " (GPU: " << CL_DEVICE_TYPE_GPU << ", CPU: " << CL_DEVICE_TYPE_CPU << ")" << std::endl;  
            std::cout << "\t\tDevice Vendor: " << device.getInfo<CL_DEVICE_VENDOR>() << std::endl;
            std::cout << "\t\tDevice Max Compute Units: " << device.getInfo<CL_DEVICE_MAX_COMPUTE_UNITS>() << std::endl;
            std::cout << "\t\tDevice Global Memory: " << device.getInfo<CL_DEVICE_GLOBAL_MEM_SIZE>() << std::endl;
            std::cout << "\t\tDevice Max Clock Frequency: " << device.getInfo<CL_DEVICE_MAX_CLOCK_FREQUENCY>() << std::endl;
            std::cout << "\t\tDevice Max Allocateable Memory: " << device.getInfo<CL_DEVICE_MAX_MEM_ALLOC_SIZE>() << std::endl;
            std::cout << "\t\tDevice Local Memory: " << device.getInfo<CL_DEVICE_LOCAL_MEM_SIZE>() << std::endl;
            std::cout << "\t\tDevice Available: " << device.getInfo< CL_DEVICE_AVAILABLE>() << std::endl;
        }  
        std::cout<< std::endl;
    } 
} 

Makefile

UNAME_S := $(shell uname -s)
# -std=c++11 -Wall -march=native
ifeq ($(UNAME_S),Linux)
CXX=clang++
CPPFLAGS=-O3
LDFLAGS=-O3
LDLIBS=-lOpenCL
endif

ifeq ($(UNAME_S),Darwin)
CXX=clang++
CPPFLAGS=-O3
LDFLAGS=-O3
LDLIBS=-framework OpenCL
endif

RM=rm -f

SRCS=device_query.cpp
OBJS=device_query.o
EXEC=device_query

all: $(OBJS)
	$(CXX) $(LDFLAGS) -o $(EXEC) $(OBJS) $(LDLIBS)

%.o: %.cpp
	$(CXX) $(CFLAGS) $(CPPFLAGS) -c $<

clean:
	$(RM) $(OBJS) $(EXEC)

dist-clean:
	$(RM) $(EXEC)