/*
 * This function advances the state of the system by nsteps timesteps. The 
 * curr is the current state of the system.
 * next is the output matrix to store the next time step into.
 */
static void fwd(TYPE *next, TYPE *curr, TYPE *vsq,
        TYPE *c_coeff, int nx, int ny, int dimx, int dimy, int radius) {

#pragma acc parallel copy(next[0:dimx * dimy], curr[0:dimx * dimy], \
        vsq[0:dimx * dimy], c_coeff[0:NUM_COEFF])
#pragma acc loop gang worker vector collapse(2)
    for (int y = 0; y < ny; y++) {
        for (int x = 0; x < nx; x++) {
            int this_offset = POINT_OFFSET(x, y, dimx, radius);
            TYPE temp = 2.0f * curr[this_offset] - next[this_offset];
            TYPE div = c_coeff[0] * curr[this_offset];
#pragma acc loop seq
            for (int d = 1; d <= radius; d++) {
                int y_pos_offset = POINT_OFFSET(x, y + d, dimx, radius);
                int y_neg_offset = POINT_OFFSET(x, y - d, dimx, radius);
                int x_pos_offset = POINT_OFFSET(x + d, y, dimx, radius);
                int x_neg_offset = POINT_OFFSET(x - d, y, dimx, radius);
                div += c_coeff[d] * (curr[y_pos_offset] +
                        curr[y_neg_offset] + curr[x_pos_offset] +
                        curr[x_neg_offset]);
            }
            next[this_offset] = temp + div * vsq[this_offset];
        }
    }
}
Esempio n. 2
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/*
 * This function advances the state of the system by nsteps timesteps. The 
 * curr is the current state of the system.
 * next is the output matrix to store the next time step into.
 */
static void fwd(TYPE *next, TYPE *curr, TYPE *vsq,
        TYPE *c_coeff, int nx, int ny, int nz, int dimx, int dimy, int dimz,
        int radius) {

    for (int z = 0; z < nz; z++) {
        for (int y = 0; y < ny; y++) {
            for (int x = 0; x < nx; x++) {
                int this_offset = POINT_OFFSET(x, y, z, dimy, dimx, radius);
                TYPE temp = 2.0f * curr[this_offset] - next[this_offset];
                TYPE div = c_coeff[0] * curr[this_offset];
                for (int d = 1; d <= radius; d++) {
                    int z_pos_offset = POINT_OFFSET(x, y, z + d, dimy, dimx,
                            radius);
                    int z_neg_offset = POINT_OFFSET(x, y, z - d, dimy, dimx,
                            radius);
                    int y_pos_offset = POINT_OFFSET(x, y + d, z, dimy, dimx,
                            radius);
                    int y_neg_offset = POINT_OFFSET(x, y - d, z, dimy, dimx,
                            radius);
                    int x_pos_offset = POINT_OFFSET(x + d, y, z, dimy, dimx,
                            radius);
                    int x_neg_offset = POINT_OFFSET(x - d, y, z, dimy, dimx,
                            radius);
                    div += c_coeff[d] * (curr[z_pos_offset] +
                            curr[z_neg_offset] + curr[y_pos_offset] +
                            curr[y_neg_offset] + curr[x_pos_offset] +
                            curr[x_neg_offset]);
                }
                next[this_offset] = temp + div * vsq[this_offset];
            }
        }
    }
}
/*
 * This function advances the state of the system by nsteps timesteps. The 
 * curr is the current state of the system.
 * next is the output matrix to store the next time step into.
 */
static void fwd(TYPE *next, TYPE *curr, TYPE *vsq,
        TYPE *c_coeff, int nx, int ny, int dimx, int dimy, int radius) {

#pragma omp parallel for collapse(2)
    for (int y = 0; y < ny; y++) {
        for (int x = 0; x < nx; x++) {
            int this_offset = POINT_OFFSET(x, y, dimx, radius);
            TYPE temp = 2.0f * curr[this_offset] - next[this_offset];
            TYPE div = c_coeff[0] * curr[this_offset];
            for (int d = 1; d <= radius; d++) {
                int y_pos_offset = POINT_OFFSET(x, y + d, dimx, radius);
                int y_neg_offset = POINT_OFFSET(x, y - d, dimx, radius);
                int x_pos_offset = POINT_OFFSET(x + d, y, dimx, radius);
                int x_neg_offset = POINT_OFFSET(x - d, y, dimx, radius);
                div += c_coeff[d] * (curr[y_pos_offset] +
                        curr[y_neg_offset] + curr[x_pos_offset] +
                        curr[x_neg_offset]);
            }
            next[this_offset] = temp + div * vsq[this_offset];
        }
    }
}
int main( int argc, char *argv[] ) {
    config conf;
    setup_config(&conf, argc, argv);
    init_progress(conf.progress_width, conf.nsteps, conf.progress_disabled);

    TYPE dx = 20.f;
    TYPE dt = 0.002f;

    // compute the pitch for perfect coalescing
    size_t dimx = conf.nx + 2*conf.radius;
    size_t dimy = conf.ny + 2*conf.radius;
    size_t nbytes = dimx * dimy * sizeof(TYPE);

    if (conf.verbose) {
        printf("x = %zu, y = %zu\n", dimx, dimy);
        printf("nsteps = %d\n", conf.nsteps);
        printf("radius = %d\n", conf.radius);
    }

    TYPE c_coeff[NUM_COEFF];
    TYPE *curr = (TYPE *)malloc(nbytes);
    TYPE *next = (TYPE *)malloc(nbytes);
    TYPE *vsq  = (TYPE *)malloc(nbytes);
    if (curr == NULL || next == NULL || vsq == NULL) {
        fprintf(stderr, "Allocations failed\n");
        return 1;
    }

    config_sources(&conf.srcs, &conf.nsrcs, conf.nx, conf.ny, conf.nsteps);
    TYPE **srcs = sample_sources(conf.srcs, conf.nsrcs, conf.nsteps, dt);

    init_data(curr, next, vsq, c_coeff, dimx, dimy, dx, dt);

    double start = seconds();
    for (int step = 0; step < conf.nsteps; step++) {
        for (int src = 0; src < conf.nsrcs; src++) {
            if (conf.srcs[src].t > step) continue;
            int src_offset = POINT_OFFSET(conf.srcs[src].x, conf.srcs[src].y,
                    dimx, conf.radius);
            curr[src_offset] = srcs[src][step];
        }

        fwd(next, curr, vsq, c_coeff, conf.nx, conf.ny, dimx, dimy,
                conf.radius);

        TYPE *tmp = next;
        next = curr;
        curr = tmp;

        update_progress(step + 1);
    }
    double elapsed_s = seconds() - start;

    finish_progress();

    float point_rate = (float)conf.nx * conf.ny / (elapsed_s / conf.nsteps);
    fprintf(stderr, "iso_r4_2x:   %8.10f s total, %8.10f s/step, %8.2f Mcells/s/step\n",
            elapsed_s, elapsed_s / conf.nsteps, point_rate / 1000000.f);

    if (conf.save_text) {
        save_text(curr, dimx, dimy, conf.ny, conf.nx, "snap.text", conf.radius);
    }

    free(curr);
    free(next);
    free(vsq);
    for (int i = 0; i < conf.nsrcs; i++) {
        free(srcs[i]);
    }
    free(srcs);
    
    return 0;
}