From c59f5a4b9b72fbff8e0c25347f1cac144c242c23 Mon Sep 17 00:00:00 2001 From: Fabio Salvini Date: Thu, 17 Nov 2016 14:24:56 +0100 Subject: [PATCH] Removed all n + 2 --- mpi_line/jacobi_mpi_line.c | 43 +++++++++++++++++++------------------- 1 file changed, 22 insertions(+), 21 deletions(-) diff --git a/mpi_line/jacobi_mpi_line.c b/mpi_line/jacobi_mpi_line.c index be18fe3..6946f58 100644 --- a/mpi_line/jacobi_mpi_line.c +++ b/mpi_line/jacobi_mpi_line.c @@ -84,6 +84,7 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in double *x; double max_diff, global_max_diff, new_x; int i, j; + int nb = n + 2; // n plus the border int rows, rows_to_transmit; int receive_pos; 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] initializing matrix\n", rank, numprocs)); */ /* 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 (j = 1; j <= n; j++) { - x[IDX(n + 2, i, j)] = init_value; + x[IDX(nb, i, j)] = init_value; } } /* Initialize boundary regions */ for (i = 0; i < rows + 2; i++) { - x[IDX(n + 2, i, 0)] = b.west; - x[IDX(n + 2, i, n + 1)] = b.east; + x[IDX(nb, i, 0)] = b.west; + x[IDX(nb, i, n + 1)] = b.east; } if (rank == 0) { 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){ 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)); */ @@ -125,30 +126,30 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in global_max_diff = 0; for (i = 1; i <= rows; i++) { 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)]); - max_diff = (double) fmax(max_diff, fabs(new_x - x[IDX(n + 2, i, j)])); - x[IDX(n + 2, i, j)] = new_x; + 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(nb, i, j)])); + x[IDX(nb, i, j)] = new_x; } } if (rank % 2 == 0) { if (rank != numprocs - 1) { // 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_Recv(&x[IDX(n + 2, rows + 1, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status); + MPI_Send(&x[IDX(nb, rows, 0)], nb, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD); + MPI_Recv(&x[IDX(nb, rows + 1, 0)], nb, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status); } if (rank != 0) { // 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_Recv(&x[IDX(n + 2, 0, 0)], n + 2, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD, &status); + MPI_Send(&x[IDX(nb, 1, 0)], nb, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD); + MPI_Recv(&x[IDX(nb, 0, 0)], nb, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD, &status); } } else { // 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_Send(&x[IDX(n + 2, 1, 0)], n + 2, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD); + MPI_Recv(&x[IDX(nb, 0, 0)], nb, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD, &status); + MPI_Send(&x[IDX(nb, 1, 0)], nb, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD); if (rank != numprocs - 1) { // 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_Send(&x[IDX(n + 2, rows, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD); + MPI_Recv(&x[IDX(nb, rows + 1, 0)], nb, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status); + 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)); */ @@ -158,15 +159,15 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in } while (global_max_diff > threshold); if (rank == 0) { - complete_x = create_sa_matrix(n + 2, n + 2); - memcpy(complete_x, x, (rows + ((rank == numprocs - 1) ? 2 : 1)) * (n + 2) * sizeof(double)); + complete_x = create_sa_matrix(nb, nb); + memcpy(complete_x, x, (rows + ((rank == numprocs - 1) ? 2 : 1)) * (nb) * sizeof(double)); rows_to_transmit = n / numprocs; receive_pos = rows + 1; for (i = 1; i < numprocs; i++) { if (i == numprocs - 1) { 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; } } else { @@ -175,7 +176,7 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in if (rank == numprocs - 1) { 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;