The difference is negligible.
void main(void)
{
long i;
int size;
for(i=0;i<99999999; i++)
size = sizeof(char *);
}
real 0m2.684s
user 0m2.690s
sys 0m0.000s
void main(void)
{
long i;
int size;
int l = sizeof(char *);
for(i=0;i<99999999; i++)
size = l;
}
real 0m2.627s
user 0m2.620s
sys 0m0.010s
> -----Original Message-----
> From: Michael Barton [mailto:[EMAIL PROTECTED]
> Sent: Friday, July 18, 2003 10:26 AM
> To: Chris "Winston" Litchfield; [email protected]
> Subject: Re: Simple Performance Speedup.
>
>
> sizeof isn't a function anyway. It's a unary operator
> evaluated at compile
> time.
> Replacing all of the calls to sizeof with a variable will in
> fact slow the
> program down, since it has to dig the value out of memory
> every time it's
> used, instead of having a constant.
>
> ----- Original Message -----
> From: "Chris "Winston" Litchfield" <[EMAIL PROTECTED]>
> To: <[email protected]>
> Sent: Thursday, July 17, 2003 7:23 PM
> Subject: Simple Performance Speedup.
>
>
> > Tip of the day.
> >
> > fread_string and other fread_* functions are used a lot.
> It would make
> > sense that they be as fast as possible....... it is why
> they are using
> HASH
> > tables for string combining...
> >
> > So.. a tip of the day.
> >
> > in db.c at the top make a variable called "charptrsize" an int.
> > in boot_db do:
> > charptrsize = sizeof(char *);
> >
> > Now you are ready.. in fread_string and other
> fread_functions that use
> > sizeof(char *) ALL OVER THE PLACE just replace it with charptrsize.
> >
> > Instant SPEEDup. Remember each unneeded function call adds
> a slight bit
> > slowdown.
> >
> > Chris "Winston" Litchfield
>
>
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