Create a gist now

Instantly share code, notes, and snippets.

hcc saxpy example
#include <random>
#include <algorithm>
#include <iostream>
#include <cmath>
// header file for the hc API
#include <hcc/hc.hpp>
#define N (1024 * 500)
int main() {
const float a = 100.0f;
float x[N];
float y[N];
// initialize the input data
std::default_random_engine random_gen;
std::uniform_real_distribution<float> distribution(-N, N);
std::generate_n(x, N, [&]() { return distribution(random_gen); });
std::generate_n(y, N, [&]() { return distribution(random_gen); });
// make a copy of for the GPU implementation
float y_gpu[N];
std::copy_n(y, N, y_gpu);
// CPU implementation of saxpy
for (int i = 0; i < N; i++) {
y[i] = a * x[i] + y[i];
}
// wrap the data buffer around with an array_view
// to let the hcc runtime to manage the data transfer
hc::array_view<float, 1> av_x(N, x);
hc::array_view<float, 1> av_y(N, y_gpu);
// launch a GPU kernel to compute the saxpy in parallel
hc::parallel_for_each(hc::extent<1>(N)
, [=](hc::index<1> i) [[hc]] {
av_y[i] = a * av_x[i] + av_y[i];
});
// verify the results
int errors = 0;
for (int i = 0; i < N; i++) {
if (fabs(y[i] - av_y[i]) > fabs(y[i] * 0.0001f))
errors++;
}
std::cout << errors << " errors" << std::endl;
return errors;
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment