DocsTutorial/example4_kernel.cl

Device code for Example 4: Poisson variate generation on the device

/*
 * Authors:
 *
 *   David Munger <mungerd@iro.umontreal.ca>        (2015)
 *   Pierre L'Ecuyer <lecuyer@iro.umontreal.ca>     (2015)
 *
 */

#include <clProbDist/poisson.clh>
#include <clRNG/mrg31k3p.clh>

#ifndef NULL
#define NULL ((void*)0)
#endif

double simulateOneRun(__global const clprobdistPoisson* dist, clrngMrg31k3pStream* stream)
{
    double output = 0.0;
    for (int i = 0; i < 100; i++) {
        double u = clrngMrg31k3pRandomU01(stream);
        int poisson_variate = clprobdistPoissonInverseCDFWithObject(dist, u, NULL);
        // modify output using poisson_variate
        output += poisson_variate / (100.0 * clprobdistPoissonMeanWithObject(dist, NULL));
    }
    return output;
}

__kernel void my_kernel(
    __global const clprobdistPoisson* dist,
    __global const clrngMrg31k3pHostStream* host_streams,
    __global double* output)
{
    size_t gid = get_global_id(0);
    clrngMrg31k3pStream stream;
    clrngMrg31k3pCopyOverStreamsFromGlobal(1, &stream, &host_streams[gid]);
    output[gid] = simulateOneRun(dist, &stream);
}