-Wall -std=c++14 -O0 -o a.out source_file.cpp, C++ (gcc)

Language: Layout:

#include <immintrin.h>  // portable to all x86 compilers
#include <stdio.h>
#include <time.h>

#define DATA float
const int BLOCK_SIZE = 16;

const int SIZE  = 256;

DATA A[SIZE][SIZE] ;
DATA B[SIZE][SIZE] ;
DATA C[SIZE][SIZE] ;
DATA C2[SIZE][SIZE] ;
DATA C3[SIZE][SIZE] ;
DATA C4[SIZE][SIZE] ;

double seconds()
{

struct timespec now;
  clock_gettime(CLOCK_MONOTONIC, &now);
  return now.tv_sec + now.tv_nsec / 1000000000.0;
}

void initialize_array(DATA a[], int size)
{
	for (int i = 0 ;  i < size ; i++)
	{
		a[i] = rand()%2;
	}
}
void initialize_2d_array(DATA a[SIZE][SIZE])
{
    for (int i = 0 ; i < SIZE ; i++)
        for (int j = 0 ; j < SIZE ; j++)
        {
            a[i][j] = rand()%2;
        }
}

void zero_2d_array(DATA a[SIZE][SIZE])
{
    for (int i = 0 ; i < SIZE ; i++)
        for (int j = 0 ; j < SIZE ; j++)
        {
            a[i][j] = 0;
        }
}

int compare(DATA A[SIZE][SIZE],DATA B[SIZE][SIZE])
{

for (int i = 0 ; i < SIZE ; i++)
        for (int j = 0 ; j < SIZE ; j++)
            if ( A[i][j] != B[i][j])
                return 0;

return 1;
}

void mat_mat(DATA A[SIZE][SIZE], DATA B[SIZE][SIZE],DATA C[SIZE][SIZE]) 
{
    for (int i = 0 ; i < SIZE ; i++)
        for (int j = 0 ; j < SIZE ; j++)
        {
            C[i][j] = 0;

for (int k = 0 ; k < SIZE ; k++)
                C[i][j]+= A[i][k]*B[k][j];
        }
}

void mat_mul(DATA C[SIZE][SIZE], DATA A[SIZE][SIZE],DATA B[SIZE][SIZE]) 
{
    for (int i = 0 ; i < BLOCK_SIZE ; i++)
        for (int j = 0 ; j < BLOCK_SIZE ; j++)
        {
            C[i][j] = 0;

for (int k = 0 ; k < BLOCK_SIZE ; k++)
                C[i][j]+= A[i][k]*B[k][j];
        }
}

void mat_mat_interchanged(DATA A[SIZE][SIZE], DATA B[SIZE][SIZE],DATA C[SIZE][SIZE]) 
{
     for (int i = 0 ; i < SIZE ; i++)
        for (int k = 0 ; k < SIZE ; k++)
        {
          //  C[i][j] = 0;

for (int j = 0 ; j < SIZE ; j++)
                //C[i][k]+= A[i][j]*B[j][k];
			                C[i][j]+= A[i][k]*B[k][j];

}
}

void mat_mat_blocked(DATA A[SIZE][SIZE], DATA B[SIZE][SIZE],DATA C[SIZE][SIZE]) 
{     for (int i = 0 ; i < SIZE  ; i+=BLOCK_SIZE)

for (int j = 0 ; j < SIZE  ; j+=BLOCK_SIZE)

for (int k = 0 ; k < SIZE  ; k+=BLOCK_SIZE)

for (int ii = 0 ; ii < BLOCK_SIZE ; ii++)
					for (int jj = 0 ; jj < BLOCK_SIZE ; jj++)

for (int kk = 0 ; kk < BLOCK_SIZE ; kk++)
						C[i+ii][j+jj]+= A[i+ii][k+kk]*B[kk+k][j+jj];
						
						
		
}

void mat_mat_blocked_interchanged(DATA A[SIZE][SIZE], DATA B[SIZE][SIZE],DATA C[SIZE][SIZE]) 
{
	 for (int i = 0 ; i < SIZE  ; i+=BLOCK_SIZE)

for (int j = 0 ; j < SIZE  ; j+=BLOCK_SIZE)

for (int k = 0 ; k < SIZE  ; k+=BLOCK_SIZE)

for (int ii = 0 ; ii < BLOCK_SIZE ; ii++)

for (int kk = 0 ; kk < BLOCK_SIZE ; kk++)
											for (int jj = 0 ; jj < BLOCK_SIZE ; jj++)

C[i+ii][j+jj]+= A[i+ii][k+kk]*B[kk+k][j+jj];
						
}

int main()
{

DATA r;
	double before,after;

initialize_2d_array(A);
	initialize_2d_array(B);

zero_2d_array( C);
 zero_2d_array( C2);
 zero_2d_array( C3);
 zero_2d_array( C4);

before = seconds();

mat_mat(A,B,C);

after = seconds();

printf("Conventional Time:%f\n",after-before);

before = seconds();

mat_mat_interchanged(A,B,C2);

after = seconds();
		printf("interchanged Time:%f\n",after-before);

before = seconds();

mat_mat_blocked(A,B,C3);

after = seconds();
	
			printf("blocked Time:%f\n",after-before);

before = seconds();

mat_mat_blocked_interchanged(A,B,C4);
	 
    after = seconds();
	
			printf("interchanged blocked Time:%f\n",after-before);

printf("verification:%d\n",compare(C,C2));
    printf("verification:%d\n",compare(C,C3));
    printf("verification:%d\n",compare(C,C4));

/*    
     before = seconds();

mat_mat_blocked(...,C3);

after = seconds();

printf("Blocked Time:%f\n",after-before);

printf("verification:%d\n",compare(C,C3));
*/

/*    
     before = seconds();

mat_mat_blocked_opt(...,C4);

after = seconds();

printf("Blocked Interchanged Time:%f\n",after-before);

printf("verification:%d\n",compare(C,C4));
*/

return 0;
}

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Compilation time: 0.72 sec, absolute running time: 0.13 sec, cpu time: 0.08 sec, memory peak: 3 Mb, absolute service time: 0,98 sec