Hello World with the SDK 2.1 on Linux
Hello,
The HelloCL from sample files works correctly, and I tested successfully a few other with --device cpu.
Following the tutorial for the latest SDK ( http://developer.amd.com/GPU/ATISTREAMSDK/pages/TutorialOpenCL.aspx ). I tried to compile the Hello World program. I get the following error:
$ g++ -o hello_world -I/usr/local/ati-stream-sdk-v2.1-lnx32/include/ -L/usr/local/ati-stream-sdk-v2.1-lnx32/lib/ test.cpp -lOpenCL
test.cpp: In function ‘int main()’:
test.cpp:35: error: no matching function for call to ‘cl:
latform::getInfo(int, std::string*)’
/usr/local/ati-stream-sdk-v2.1-lnx32/include/CL/cl.hpp:1388: note: candidates are: cl_int cl:latform::getInfo(cl_platform_info, cl::STRING_CLASS*) const
test.cpp: At global scope:
test.cpp:112: error: expected constructor, destructor, or type conversion before ‘char’
test.cpp:113: error: expected constructor, destructor, or type conversion before ‘void’
$
The details of the platform are as follows:
$ uname -a
Linux office 2.6.31.13-desktop586-1mnb #1 SMP Tue Apr 27 20:38:56 EDT 2010 i686 Intel(R) Core(TM)2 CPU 4400 @ 2.00GHz GNU/Linux
$ gcc --version
gcc (GCC) 4.4.1
SDK is installed in /usr/local/ati-stream-sdk-v2.1-lnx32
LD_LIBRARY_PATH includes /usr/local/ati-stream-sdk-v2.1-lnx32/lib/x86
Could anyone please correct the code or any other mistake please?
TIA,
sine
#include <utility> #define __NO_STD_VECTOR // Use cl::vector and cl::string and #define __NO_STD_STRING // not STL versions, more on this later #include <CL/cl.hpp> #include <cstdio> #include <cstdlib> #include <fstream> #include <iostream> #include <string> #include <iterator> const std::string hw("Hello World\n"); inline void checkErr(cl_int err, const char * name) { if (err != CL_SUCCESS) { std::cerr << "ERROR: " << name << " (" << err << ")" << std::endl; exit(EXIT_FAILURE); } } int main(void) { cl_int err; cl::vector< cl::Platform > platformList; cl::Platform::get(&platformList); checkErr(platformList.size()!=0 ? CL_SUCCESS : -1, "cl::Platform::get"); std::cerr << "Platform number is: " << platformList.size() << std::endl; std::string platformVendor; platformList[0].getInfo(CL_PLATFORM_VENDOR, &platformVendor); std::cerr << "Platform is by: " << platformVendor << "\n"; cl_context_properties cprops[3] = {CL_CONTEXT_PLATFORM, (cl_context_properties)(platformList[0])(), 0}; cl::Context context( CL_DEVICE_TYPE_CPU, cprops, NULL, NULL, &err); checkErr(err, "Conext::Context()"); char * outH = new char[hw.length()+1]; cl::Buffer outCL( context, CL_MEM_WRITE_ONLY | CL_MEM_USE_HOST_PTR, hw.length()+1, outH, &err); checkErr(err, "Buffer::Buffer()"); cl::vector<cl::Device> devices; devices = context.getInfo<CL_CONTEXT_DEVICES>(); checkErr( devices.size() > 0 ? CL_SUCCESS : -1, "devices.size() > 0"); std::ifstream file("lesson1_kernels.cl"); checkErr(file.is_open() ? CL_SUCCESS:-1, "lesson1_kernel.cl"); std::string prog( std::istreambuf_iterator<char>(file), (std::istreambuf_iterator<char>())); cl::Program::Sources source( 1, std::make_pair(prog.c_str(), prog.length()+1)); cl::Program program(context, source); err = program.build(devices,""); checkErr(file.is_open() ? CL_SUCCESS : -1, "Program::build()"); cl::Kernel kernel(program, "hello", &err); checkErr(err, "Kernel::Kernel()"); err = kernel.setArg(0, outCL); checkErr(err, "Kernel::setArg()"); cl::CommandQueue queue(context, devices[0], 0, &err); checkErr(err, "CommandQueue::CommandQueue()"); cl::Event event; err = queue.enqueueNDRangeKernel( kernel, cl::NullRange, cl::NDRange(hw.length()+1), cl::NDRange(1, 1), NULL, &event); checkErr(err, "ComamndQueue::enqueueNDRangeKernel()"); event.wait(); err = queue.enqueueReadBuffer( outCL, CL_TRUE, 0, hw.length()+1, outH); checkErr(err, "ComamndQueue::enqueueReadBuffer()"); std::cout << outH; return EXIT_SUCCESS; } #pragma OPENCL EXTENSION cl_khr_byte_addressable_store : enable __constant char hw[] = "Hello World\n"; __kernel void hello(__global char * out) { size_t tid = get_global_id(0); out[tid] = hw[tid]; }
Originally posted by: omkaranathan You have to change CL_DEVICE_TYPE_GPU to CL_DEVICE_TYPE_CPU in clCreateContextFromType() call in the second program above to run in CPU.
Yep it works now! Thanks. Now I feel like I am 'in'. 
