[Openmp-dev] Segmentation fault libomptarget.so

[Talita Perciano via Openmp-dev]

Hi,

I'm trying openmp offloading to gpu and I'm getting a segfault when trying
to run a test code. I followed the instructions explained here
https://www.hahnjo.de/blog/2018/10/08/clang-7.0-openmp-offloading-nvidia.html
.

Here is the piece of code I'm trying to run:

#include <malloc.h>
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char* argv[])
{
    if (argc != 2)
    {
        printf("Usage: %s \n", argv[0]);
        return 0;
    }

    int n = atoi(argv[1]);

    double* x = (double*)malloc(sizeof(double) * n);
    double* y = (double*)malloc(sizeof(double) * n);

    double idrandmax = 1.0 / RAND_MAX;
    double a = idrandmax * rand();
    for (int i = 0; i < n; i++)
    {
        x[i] = idrandmax * rand();
        y[i] = idrandmax * rand();
    }
    printf("Here\n\n");
    #pragma omp target
    #pragma omp parallel for
    {
        for (int i = 0; i < n; i++)
            y[i] += a * x[i];
    }

    double avg = 0.0, min = y[0], max = y[0];
    for (int i = 0; i < n; i++)
    {
        avg += y[i];
        if (y[i] > max) max = y[i];
        if (y[i] < min) min = y[i];
    }

    printf("min = %f, max = %f, avg = %f\n", min, max, avg / n);

    free(x);
    free(y);

    return 0;
}

I'm compiling the code like this: clang -fopenmp -fopenmp-targets=nvptx64
-O2 example.c
When I run I get a Segmentation fault immediately.

Any thoughts?

Thanks!
Talita
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