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Removed all n + 2

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This commit is contained in:
Fabio Salvini 2016-11-17 14:24:56 +01:00
parent 3c4dfda3ee
commit c59f5a4b9b
1 changed files with 22 additions and 21 deletions
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43
mpi_line/jacobi_mpi_line.c
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@ -84,6 +84,7 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in
double *x; double *x;
double max_diff, global_max_diff, new_x; double max_diff, global_max_diff, new_x;
int i, j; int i, j;
int nb = n + 2; // n plus the border
int rows, rows_to_transmit; int rows, rows_to_transmit;
int receive_pos; int receive_pos;
MPI_Status status; MPI_Status status;
@ -96,25 +97,25 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in
LOG(printf("[Process %d/%d] rows: %d\n", rank, numprocs, rows)); LOG(printf("[Process %d/%d] rows: %d\n", rank, numprocs, rows));
/* LOG(printf("[Process %d/%d] initializing matrix\n", rank, numprocs)); */ /* LOG(printf("[Process %d/%d] initializing matrix\n", rank, numprocs)); */
/* Initialize the matrix */ /* Initialize the matrix */
x = create_sa_matrix(rows + 2, n + 2); x = create_sa_matrix(rows + 2, nb);
for (i = 0; i < rows + 2; i++) { for (i = 0; i < rows + 2; i++) {
for (j = 1; j <= n; j++) { for (j = 1; j <= n; j++) {
x[IDX(n + 2, i, j)] = init_value; x[IDX(nb, i, j)] = init_value;
} }
} }
/* Initialize boundary regions */ /* Initialize boundary regions */
for (i = 0; i < rows + 2; i++) { for (i = 0; i < rows + 2; i++) {
x[IDX(n + 2, i, 0)] = b.west; x[IDX(nb, i, 0)] = b.west;
x[IDX(n + 2, i, n + 1)] = b.east; x[IDX(nb, i, n + 1)] = b.east;
} }
if (rank == 0) { if (rank == 0) {
for (i = 1; i <= n + 1; i++) { for (i = 1; i <= n + 1; i++) {
x[IDX(n + 2, 0, i)] = b.north; x[IDX(nb, 0, i)] = b.north;
} }
} }
if (rank == numprocs - 1){ if (rank == numprocs - 1){
for (i = 1; i < n + 1; i++) { for (i = 1; i < n + 1; i++) {
x[IDX(n + 2, rows + 1, i)] = b.south; x[IDX(nb, rows + 1, i)] = b.south;
} }
} }
/* LOG(printf("[Process %d/%d] matrix initialized\n", rank, numprocs)); */ /* LOG(printf("[Process %d/%d] matrix initialized\n", rank, numprocs)); */
@ -125,30 +126,30 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in
global_max_diff = 0; global_max_diff = 0;
for (i = 1; i <= rows; i++) { for (i = 1; i <= rows; i++) {
for (j = 1; j <= n; j++) { for (j = 1; j <= n; j++) {
new_x = 0.25 * (x[IDX(n + 2, i - 1, j)] + x[IDX(n + 2, i, j + 1)] + x[IDX(n + 2, i + 1, j)] + x[IDX(n + 2, i, j - 1)]); new_x = 0.25 * (x[IDX(nb, i - 1, j)] + x[IDX(nb, i, j + 1)] + x[IDX(nb, i + 1, j)] + x[IDX(nb, i, j - 1)]);
max_diff = (double) fmax(max_diff, fabs(new_x - x[IDX(n + 2, i, j)])); max_diff = (double) fmax(max_diff, fabs(new_x - x[IDX(nb, i, j)]));
x[IDX(n + 2, i, j)] = new_x; x[IDX(nb, i, j)] = new_x;
} }
} }
if (rank % 2 == 0) { if (rank % 2 == 0) {
if (rank != numprocs - 1) { if (rank != numprocs - 1) {
// Send and receive south border // Send and receive south border
MPI_Send(&x[IDX(n + 2, rows, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD); MPI_Send(&x[IDX(nb, rows, 0)], nb, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD);
MPI_Recv(&x[IDX(n + 2, rows + 1, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status); MPI_Recv(&x[IDX(nb, rows + 1, 0)], nb, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status);
} }
if (rank != 0) { if (rank != 0) {
// Send and receive north border // Send and receive north border
MPI_Send(&x[IDX(n + 2, 1, 0)], n + 2, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD); MPI_Send(&x[IDX(nb, 1, 0)], nb, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD);
MPI_Recv(&x[IDX(n + 2, 0, 0)], n + 2, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD, &status); MPI_Recv(&x[IDX(nb, 0, 0)], nb, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD, &status);
} }
} else { } else {
// Receive and send north border // Receive and send north border
MPI_Recv(&x[IDX(n + 2, 0, 0)], n + 2, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD, &status); MPI_Recv(&x[IDX(nb, 0, 0)], nb, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD, &status);
MPI_Send(&x[IDX(n + 2, 1, 0)], n + 2, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD); MPI_Send(&x[IDX(nb, 1, 0)], nb, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD);
if (rank != numprocs - 1) { if (rank != numprocs - 1) {
// Receive and send south border // Receive and send south border
MPI_Recv(&x[IDX(n + 2, rows + 1, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status); MPI_Recv(&x[IDX(nb, rows + 1, 0)], nb, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status);
MPI_Send(&x[IDX(n + 2, rows, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD); MPI_Send(&x[IDX(nb, rows, 0)], nb, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD);
} }
} }
/* LOG(printf("[Process %d/%d] max_diff: %f\n", rank, numprocs, max_diff)); */ /* LOG(printf("[Process %d/%d] max_diff: %f\n", rank, numprocs, max_diff)); */
@ -158,15 +159,15 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in
} while (global_max_diff > threshold); } while (global_max_diff > threshold);
if (rank == 0) { if (rank == 0) {
complete_x = create_sa_matrix(n + 2, n + 2); complete_x = create_sa_matrix(nb, nb);
memcpy(complete_x, x, (rows + ((rank == numprocs - 1) ? 2 : 1)) * (n + 2) * sizeof(double)); memcpy(complete_x, x, (rows + ((rank == numprocs - 1) ? 2 : 1)) * (nb) * sizeof(double));
rows_to_transmit = n / numprocs; rows_to_transmit = n / numprocs;
receive_pos = rows + 1; receive_pos = rows + 1;
for (i = 1; i < numprocs; i++) { for (i = 1; i < numprocs; i++) {
if (i == numprocs - 1) { if (i == numprocs - 1) {
rows_to_transmit++; rows_to_transmit++;
} }
MPI_Recv(&complete_x[IDX(n + 2, receive_pos, 0)], rows_to_transmit * (n + 2), MPI_DOUBLE, i, TAG_MATRIX, MPI_COMM_WORLD, &status); MPI_Recv(&complete_x[IDX(nb, receive_pos, 0)], rows_to_transmit * (nb), MPI_DOUBLE, i, TAG_MATRIX, MPI_COMM_WORLD, &status);
receive_pos += n / numprocs; receive_pos += n / numprocs;
} }
} else { } else {
@ -175,7 +176,7 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in
if (rank == numprocs - 1) { if (rank == numprocs - 1) {
rows_to_transmit++; rows_to_transmit++;
} }
MPI_Send(&x[IDX(n + 2, 1, 0)], rows_to_transmit * (n + 2), MPI_DOUBLE, 0, TAG_MATRIX, MPI_COMM_WORLD); MPI_Send(&x[IDX(nb, 1, 0)], rows_to_transmit * (nb), MPI_DOUBLE, 0, TAG_MATRIX, MPI_COMM_WORLD);
} }
return complete_x; return complete_x;