Re: Is ther any sense in *= and matrices?

[tmoran@acm.org]

> > >about 19 seconds, and the "+" version took about 55 seconds. That's
> > took 4.38 and 3.28 seconds, a factor of 1.33, and using Gnat 3.15p
> I'm using gcc 2.95.2 on a Sunblade 2000. I can't post the code,
  Here's my code.  Please try it on the Sunblade 2000 with gcc 2.95.2
and let us know the results.
#include <stdio.h>
#include <time.h>
#define N 3
        // 4.386/3.275= 1.33              10M            N=3

struct matrices{int x[N][N];};

struct matrices f(struct matrices left, struct matrices right){
        struct matrices result;
        int i,j;
        for(i=0;i<N;i++)
                for(j=0;j<N;j++)
                        result.x[i][j]=left.x[i][j]+right.x[i][j];
    return result;
}

void add_to(struct matrices left, struct matrices right){
        int i,j;
        for(i=0;i<N;i++)
                for(j=0;j<N;j++)
                        left.x[i][j]+=right.x[i][j];
}

void set(struct matrices m, int v){
        int i,j;
        for(i=0;i<N;i++)
                for(j=0;j<N;j++)
                        m.x[i][j]=v;
}

void main() {
        int i;
        clock_t t0,t1,t2;
        matrices a;
        matrices b;
        printf("Go ");
        set(a,0);
        set(b,0);
        add_to(a,b);
        a = f(a,b);
        t0 = clock();
        for(i=0;i<10000000;i++)
          add_to(a,b);
        t1 = clock();
        for(i=0;i<10000000;i++)
          a = f(a,b);
        t2=clock();
        printf("%i %i %i",(int)CLOCKS_PER_SEC,(int)(t1-t0),(int)(t2-t1));
}