#include <stdio.h>

#include <stdlib.h>

#include <mkl.h>

#define LOOP_COUNT 100

#define M 20

#define P 200

#define N 20

int main()

{

double *A, *B, *C;

int i,j,r,max_threads,size;

double alpha, beta;

double s_initial, s_elapsed;

printf("Intializing data for matrix multiplication C=A*B for matrix\n\n"

" A(%i*%i) and matrix B(%i*%i)\n",M,P,P,N);

alpha = 1.0;

beta = 0.0;

printf("Allocating memory for matrices aligned on 64-byte boundary for better performance \n\n");

A = ( double *)mkl_malloc(M*P*sizeof( double ),64);

B = ( double *)mkl_malloc(N*P*sizeof( double ),64);

C = ( double *)mkl_malloc(M*N*sizeof( double ),64);

if (A == NULL || B == NULL || C == NULL)

{

printf("Error: can`t allocate memory for matrices.\n\n");

mkl_free(A);

mkl_free(B);

mkl_free(C);

return 1;

}

printf("Intializing matrix data\n\n");

size = M*P;

for (i = 0; i < size; ++i)

{

A[i] = ( double )(i+1);

}

size = N*P;

for (i = 0; i < size; ++i)

{

B[i] = ( double )(i-1);

}

printf("Finding max number of threads can use for parallel runs \n\n");

max_threads = mkl_get_max_threads();

printf("Running from 1 to %i threads \n\n",max_threads);

for (i = 1; i <= max_threads; ++i)

{

size = M*N;

for (j = 0; j < size; ++j)

{

C[j] = 0.0;

}

printf("Requesting to use %i threads \n\n",i);

mkl_set_num_threads(i);

printf("Measuring performance of matrix product using dgemm function\n"

" via CBLAS interface on %i threads \n\n",i);

s_initial = dsecnd();

for (r = 0; r < LOOP_COUNT; ++r)

{

cblas_dgemm(CblasRowMajor, CblasNoTrans, CblasNoTrans, M, N, P, alpha, A, P, B, N, beta, C, N);

// multiply matrices with cblas_dgemm;

}

s_elapsed = (dsecnd() - s_initial) / LOOP_COUNT;

printf("Matrix multiplication using dgemm completed \n"

" at %.5f milliseconds using %d threads \n\n",

(s_elapsed * 1000),i);

printf("Output the result: \n");

size = M*N;

for (i = 0; i < size; ++i)

{

printf("%i\t",(int)C[i]);

if (i % N == N - 1)

printf("\n");

}

}

printf("Dellocating memory\n");

mkl_free(A);

mkl_free(B);

mkl_free(C);

return 0;

}