int main(int argc, char** argv) {
// Initialize the CUDA driver API library.
CUresult result = cuInit(0);
// Create a CUDA device and context.
DevicePtr device;
result = CreateCuDevice(0, &device);
ContextPtr context;
result = CreateCuContext(device, 0, &context);
// Initialize the MGPU Sort engine. This is the C interface, but you can
// also use the RAII MgpuSort type in mgpusort.hpp. Pass the directory name
// that holds the .cubin kernel files. If these aren't already built, use
// build_all.bat in /kernels.
sortEngine_t engine;
sortStatus_t status = sortCreateEngine("../../src/cubin/", &engine);
if(SORT_STATUS_SUCCESS != status) {
printf("Could not initialize MGPU Sort:\n\t%s",
sortStatusString(status));
return 0;
}
// Create some test data in an std::vector. Generate uints with 32 random
// bits.
int NumElements = 128;
std::tr1::uniform_int<uint> r(0, 0xffffffff);
std::vector<uint> hostData(NumElements);
for(int i(0); i < NumElements; ++i)
hostData[i] = r(mt19937);
// Print the unsorted values to screen.
printf("%d unsorted values:\n", NumElements);
PrintArrayToScreen(&hostData[0], NumElements);
// Let MGPU allocate device memory for the source and destination buffers.
// You can do this yourself with many allocation options. Refer to
// mgpusort.h comments for more info. Pass 0 for valueCount to indicate that
// we just want to sort keys, not key-value tuples.
sortData_t deviceData;
status = sortCreateData(engine, NumElements, 0, &deviceData);
// These are resetting the default values, but it's good to be sure that we
// are sorting over the desired bits in the key. For best performance only
// sort over the bits that actually differ.
deviceData->firstBit = 0;
deviceData->endBit = 32;
// Copy the host data to the device array. sortData_d::parity indicates
// which of the arrays holds the active data. The other array is temp
// buffer.
cuMemcpyHtoD(deviceData->keys[deviceData->parity], &hostData[0],
sizeof(uint) * NumElements);
// Sort the elements.
sortArray(engine, deviceData);
// Retrieve the sorted elements.
cuMemcpyDtoH(&hostData[0], deviceData->keys[deviceData->parity],
sizeof(uint) * NumElements);
// Free the device arrays.
sortDestroyData(deviceData);
// Free the sort engine
sortReleaseEngine(engine);
// Print the unsorted values to screen.
printf("\n\n%d sorted values:\n", NumElements);
PrintArrayToScreen(&hostData[0], NumElements);
}
virtual const char* what() const throw() {
return sortStatusString(_status);
}
