BetterSequencialMatrixSearch.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <time.h>
   4
   5 const int m_rows = 40000;
   6 const int m_cols = m_rows;
   7
   8 int hv = 0;
   9 int **matrix;
  10
  11
  12 int main(void){
  13   printf("1st --> Allocate aligned memory\n");
  14   clock_t t_t1; t_t1 = clock();
  15   size_t rows_size = m_rows * sizeof(int*);
  16   matrix = malloc(rows_size);
  17   if(matrix == NULL){
  18     perror("malloc failled");
  19     return 1;
  20   }
  21   size_t data_size = (size_t)m_rows * m_cols * sizeof(int);
  22   int *data;
  23   if(posix_memalign((void**)&data, 64, data_size) != 0){
  24     perror("not able to alocate memory");
  25     free(matrix);
  26     return 1;
  27   }
  28   t_t1 = clock() - t_t1;
  29   double t1_ttaken = ((double)t_t1)/CLOCKS_PER_SEC;
  30   printf(" %f sec \n",t1_ttaken);
  31
  32   printf("2nd --> Populate the matrix\n");
  33   clock_t t_t2; t_t2 = clock();
  34   for(int r = 0; r<m_rows;r++){
  35     matrix[r] = data + r * m_cols;
  36   }
  37   for(int r = 0; r < m_rows; r++){
  38     for(int c = 0; c < m_cols; c++){
  39       matrix[r][c] = r*m_cols+c;
  40     }
  41   }
  42   t_t2 = clock() - t_t2;
  43   double t2_ttaken = ((double)t_t2)/CLOCKS_PER_SEC;
  44   printf(" %f sec\n ",t2_ttaken);
  45
  46   printf("3rd --> Search matrix \n");
  47   clock_t t_t3; t_t3 = clock();
  48   for(int r = 0; r < m_rows; r++){
  49     for(int c = 0; c < m_cols; c++){
  50       if(matrix[r][c] > hv){
  51         hv = matrix[r][c];
  52       }
  53     }
  54   }
  55   t_t3 = clock() - t_t3;
  56   double t3_ttaken = ((double)t_t3)/CLOCKS_PER_SEC;
  57   printf(" %f sec\n",t3_ttaken);
  58
  59   printf("Done\n The biggest value found is  %d", hv);
  60   free(matrix);
  61   free(data);
  62   return 0;
  63 }
  64
  65