As the result of a little discussion with Scott Reynolds about
performance wins/losses by the use of different variable types I
compiled a little test program (see the source at the end). The results
on my LCII (68030/16MHz) look surprising to me:

--- copyvalue.result -----------------------------------
Start simple copy:
long: 13 seconds
int: 27 seconds
short: 40 seconds
char: 53 seconds
Start subroutine calls:
long: 62 seconds
int: 67 seconds
short: 72 seconds
char: 78 seconds
--------------------------------------------------------

I don't know why simple copying the value from one variable to another
takes such different times. If I look at the MC68000 timing tables, a
MOVE instruction takes always fewer cycles for a word than for a long.

Also I'm surprised by the big differences between int and short. I
always thought 'int' and 'long' are the same on a 32-bit OS like MacBSD
or MacOS.

If we trust these tests, we should move from int to long as the
"standard" variable type!

Made I a mistake or what is the explanation for this?

Markus

-----------------------------------------------------------------------
  Markus Hitter             Voice: ++49/651/828172
                            Email: hitterm@trier.fh-rpl.de
  Trier (Germany)           WWW: http://www.trier.fh-rpl.de/~hitterm

--- copyvalue.c ----------------------------------------

/* compiled with 'cc -O -o copyvalue copyvalue.c'
   (like the default for the kernel). */

#include <stdio.h>
#include <time.h>

void calllong (long, long);
void callint (int, int);
void callshort (short, short);
void callchar (char, char);

main()
{
        long i;
        time_t start;
        long lfrom, lto;
        int ifrom, ito;
        short sfrom, sto;
        char cfrom, cto;

        printf ("Start simple copy: \n");
        start = time (NULL);

        for (i=0; i<20000000; i++) {
                lto = lfrom;
        }
        printf ("long: %G seconds\n", difftime (time (NULL), start));

        for (i=0; i<20000000; i++) {
                ito = ifrom;
        }
        printf ("int: %G seconds\n", difftime (time (NULL), start));

        for (i=0; i<20000000; i++) {
                sto = sfrom;
        }
        printf ("short: %G seconds\n", difftime (time (NULL), start));

        for (i=0; i<20000000; i++) {
                cto = cfrom;
        }
        printf ("char: %G seconds\n", difftime (time (NULL), start));

        printf ("Start subroutine calls: \n");

        for (i=0; i<1000000; i++) {
                calllong (lfrom, lto);
        }
        printf ("long: %G seconds\n", difftime (time (NULL), start));

        for (i=0; i<1000000; i++) {
                callint (ifrom, ito);
        }
        printf ("int: %G seconds\n", difftime (time (NULL), start));

        for (i=0; i<1000000; i++) {
                callshort (sfrom, sto);
        }
        printf ("short: %G seconds\n", difftime (time (NULL), start));

        for (i=0; i<1000000; i++) {
                callchar (cfrom, cto);
        }
        printf ("char: %G seconds\n", difftime (time (NULL), start));
        return 0;
}

void calllong (long a, long b) {}
void callint (int a, int b) {}
void callshort (short a, short b) {}
void callchar (char a, char b) {}
--------------------------------------------------------