Write a C program that compare the time required to compute the product of two 10,000 x 10,000 matrices with and without optimization for locality.

Question

Write a C program that compare the time required to compute the product of two 10,000 x 10,000 matrices with and without optimization for locality.

Answer 1

Arrays that large blow up the heap

you can SIMULATE the timing exercise by multiplying corresponding elements of

TWO (2) arrays of 10000 numbers, WITHING a loop that executes 10000 times

#include <stdio.h>

#include <time.h>

#define N (1000)

void Go()

{

int A[N][N];

int B[N][N];

int C[N][N];

int iLoop,jLoop, kLoop;

int sum=0;

clock_t start = clock();

printf("%12.6f \n",start);

for (iLoop = 0; iLoop < N; iLoop++)

{

for (jLoop = 0; jLoop < N; jLoop++)

{

C[iLoop][jLoop] = 0;

for (kLoop = 0; kLoop < N; kLoop++)

{

C[iLoop][jLoop] += A[iLoop][kLoop]*B[kLoop][jLoop];

}

}

printf("%d\n",iLoop);

}

clock_t stop = clock();

double ttimediff = (double) (stop-start);

printf("%12.6f",ttimediff);

}

int main()

{

Go();

}