14 Nov
2003
14 Nov
'03
7:27 a.m.
On Fri, 2003-11-14 at 12:00, Hans Franke wrote:
So, why do you assume I should/must/want to address only within a
segment?
/* Fill a
block of memory with 0's. */
void foofill (start, end)
{
char *start, *end; /* memory pointers */
while (start < end) { /* until we reach the end... */
*start++= 0; /* write 0, incr pointer... */
}
}
So, where's the problem?
start and end are memory ponters, and thus belog to one
segemt. The whole operation is meaningless if they would
belong to different segments. The comparsion generated
for the while is a simple 16 bit compare.
...which technique [16-bit compare] will cause unpleasant side effects,
should the memory block be 65537 bytes long, for example.
BTW: above example is exactly one thing why I hate C.
basicly every compiler will generate a stupid loop, while
in assembly a REP STOSW would do the trick at maximum
speed possible.
Oh really....! OK you win!
EOT