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Used macro instead of function to get the array index

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This commit is contained in:
Fabio Salvini
2016-11-17 14:14:59 +01:00
parent c38550c8aa
commit 3c4dfda3ee
4 changed files with 29 additions and 30 deletions
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2
mpi_line/jacobi.conf
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@@ -1,7 +1,7 @@
# Configuration file for the Jacobi project.
# The size of the matrix (borders excluded).
N 5000
N 5
# The value at each border.
NORTH 0.0

38
mpi_line/jacobi_mpi_line.c
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@@ -69,7 +69,7 @@ int main(int argc, char* argv[]) {
endwtime = MPI_Wtime();
printf("Wall clock time: %fs\n", endwtime - startwtime);
printf("Iterations: %d\n", iterations);
/* print_sa_matrix(x, n + 2, n + 2); */
print_sa_matrix(x, n + 2, n + 2);
}
destroy_sa_matrix(x);
@@ -99,22 +99,22 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in
x = create_sa_matrix(rows + 2, n + 2);
for (i = 0; i < rows + 2; i++) {
for (j = 1; j <= n; j++) {
x[sa_index(n + 2, i, j)] = init_value;
x[IDX(n + 2, i, j)] = init_value;
}
}
/* Initialize boundary regions */
for (i = 0; i < rows + 2; i++) {
x[sa_index(n + 2, i, 0)] = b.west;
x[sa_index(n + 2, i, n + 1)] = b.east;
x[IDX(n + 2, i, 0)] = b.west;
x[IDX(n + 2, i, n + 1)] = b.east;
}
if (rank == 0) {
for (i = 1; i <= n + 1; i++) {
x[sa_index(n + 2, 0, i)] = b.north;
x[IDX(n + 2, 0, i)] = b.north;
}
}
if (rank == numprocs - 1){
for (i = 1; i < n + 1; i++) {
x[sa_index(n + 2, rows + 1, i)] = b.south;
x[IDX(n + 2, rows + 1, i)] = b.south;
}
}
/* LOG(printf("[Process %d/%d] matrix initialized\n", rank, numprocs)); */
@@ -125,30 +125,30 @@ 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[sa_index(n + 2, i - 1, j)] + x[sa_index(n + 2, i, j + 1)] + x[sa_index(n + 2, i + 1, j)] + x[sa_index(n + 2, i, j - 1)]);
max_diff = (double) fmax(max_diff, fabs(new_x - x[sa_index(n + 2, i, j)]));
x[sa_index(n + 2, i, j)] = new_x;
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;
}
}
if (rank % 2 == 0) {
if (rank != numprocs - 1) {
// Send and receive south border
MPI_Send(&x[sa_index(n + 2, rows, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD);
MPI_Recv(&x[sa_index(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(n + 2, rows + 1, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status);
}
if (rank != 0) {
// Send and receive north border
MPI_Send(&x[sa_index(n + 2, 1, 0)], n + 2, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD);
MPI_Recv(&x[sa_index(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(n + 2, 0, 0)], n + 2, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD, &status);
}
} else {
// Receive and send north border
MPI_Recv(&x[sa_index(n + 2, 0, 0)], n + 2, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD, &status);
MPI_Send(&x[sa_index(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(n + 2, 1, 0)], n + 2, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD);
if (rank != numprocs - 1) {
// Receive and send south border
MPI_Recv(&x[sa_index(n + 2, rows + 1, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status);
MPI_Send(&x[sa_index(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(n + 2, rows, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD);
}
}
/* LOG(printf("[Process %d/%d] max_diff: %f\n", rank, numprocs, max_diff)); */
@@ -166,7 +166,7 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in
if (i == numprocs - 1) {
rows_to_transmit++;
}
MPI_Recv(&complete_x[sa_index(n + 2, receive_pos, 0)], rows_to_transmit * (n + 2), MPI_DOUBLE, i, TAG_MATRIX, MPI_COMM_WORLD, &status);
MPI_Recv(&complete_x[IDX(n + 2, receive_pos, 0)], rows_to_transmit * (n + 2), MPI_DOUBLE, i, TAG_MATRIX, MPI_COMM_WORLD, &status);
receive_pos += n / numprocs;
}
} else {
@@ -175,7 +175,7 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in
if (rank == numprocs - 1) {
rows_to_transmit++;
}
MPI_Send(&x[sa_index(n + 2, 1, 0)], rows_to_transmit * (n + 2), MPI_DOUBLE, 0, TAG_MATRIX, MPI_COMM_WORLD);
MPI_Send(&x[IDX(n + 2, 1, 0)], rows_to_transmit * (n + 2), MPI_DOUBLE, 0, TAG_MATRIX, MPI_COMM_WORLD);
}
return complete_x;

8
utils/utils.c
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@@ -1,5 +1,6 @@
#include <stdio.h>
#include <stdlib.h>
#include "../utils/utils.h"
double *create_sa_matrix(int rows, int cols) {
double *x;
@@ -12,16 +13,11 @@ void destroy_sa_matrix(double *x) {
free(x);
}
int sa_index(int cols, int r, int c) {
return r * cols + c;
}
void print_sa_matrix(double *x, int rows, int cols) {
int i, j;
for (i = 0; i < rows; i++) {
for (j = 0; j < cols; j++) {
printf("%f\t", x[sa_index(cols, i, j)]);
printf("%f\t", x[IDX(cols, i, j)]);
}
printf("\n");
}

11
utils/utils.h
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@@ -9,6 +9,13 @@
# define LOG(x) (void) 0
#endif
/*
* Macro used with single array matrices to
* get the array index given the number of columns,
* the row index and the column index.
*/
#define IDX(cols, r, c) ((r) * (cols) + (c))
typedef struct borders {
double north;
double east;
@@ -27,10 +34,6 @@ double *create_sa_matrix(int rows, int cols);
*/
void destroy_sa_matrix(double *x);
/*
* Get the index for the single array matrix
* that correspond to the given row and column.
*/
int sa_index(int cols, int r, int c);
/*