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hpc-2022-g3/OpenMP/linear-algebra/kernels/cholesky/cholesky.c
Alessandro Capotondi e11b42a518 init commit
2022-11-11 13:23:45 +01:00

101 lines
2.3 KiB
C

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <math.h>
/* Include polybench common header. */
#include <polybench.h>
/* Include benchmark-specific header. */
/* Default data type is double, default size is 4000. */
#include "cholesky.h"
/* Array initialization. */
static void init_array(int n,
DATA_TYPE POLYBENCH_1D(p, N, n),
DATA_TYPE POLYBENCH_2D(A, N, N, n, n))
{
int i, j;
for (i = 0; i < n; i++)
{
p[i] = 1.0 / n;
for (j = 0; j < n; j++)
A[i][j] = 1.0 / n;
}
}
/* DCE code. Must scan the entire live-out data.
Can be used also to check the correctness of the output. */
static void print_array(int n,
DATA_TYPE POLYBENCH_2D(A, N, N, n, n))
{
int i, j;
for (i = 0; i < n; i++)
for (j = 0; j < n; j++)
{
fprintf(stderr, DATA_PRINTF_MODIFIER, A[i][j]);
if ((i * N + j) % 20 == 0)
fprintf(stderr, "\n");
}
}
/* Main computational kernel. The whole function will be timed,
including the call and return. */
static void kernel_cholesky(int n,
DATA_TYPE POLYBENCH_1D(p, N, n),
DATA_TYPE POLYBENCH_2D(A, N, N, n, n))
{
int i, j, k;
DATA_TYPE x;
for (i = 0; i < _PB_N; ++i)
{
x = A[i][i];
for (j = 0; j <= i - 1; ++j)
x = x - A[i][j] * A[i][j];
p[i] = 1.0 / sqrt(x);
for (j = i + 1; j < _PB_N; ++j)
{
x = A[i][j];
for (k = 0; k <= i - 1; ++k)
x = x - A[j][k] * A[i][k];
A[j][i] = x * p[i];
}
}
}
int main(int argc, char **argv)
{
/* Retrieve problem size. */
int n = N;
/* Variable declaration/allocation. */
POLYBENCH_2D_ARRAY_DECL(A, DATA_TYPE, N, N, n, n);
POLYBENCH_1D_ARRAY_DECL(p, DATA_TYPE, N, n);
/* Initialize array(s). */
init_array(n, POLYBENCH_ARRAY(p), POLYBENCH_ARRAY(A));
/* Start timer. */
polybench_start_instruments;
/* Run kernel. */
kernel_cholesky(n, POLYBENCH_ARRAY(p), POLYBENCH_ARRAY(A));
/* Stop and print timer. */
polybench_stop_instruments;
polybench_print_instruments;
/* Prevent dead-code elimination. All live-out data must be printed
by the function call in argument. */
polybench_prevent_dce(print_array(n, POLYBENCH_ARRAY(A)));
/* Be clean. */
POLYBENCH_FREE_ARRAY(A);
POLYBENCH_FREE_ARRAY(p);
return 0;
}