Am Sonntag, 12. Januar 2003 23:21 schrieb Rob Wilkens:
> On Sun, 2003-01-12 at 16:59, Adam Kropelin wrote:
> > Congratulations. You've possibly increased the speed of an error path by
> > an infintessimal amount at the expense of increasing the size of kernel
> > image and making the code harder to read and maintain. (I say "possibly"
> > since with caching effects you may have actually slowed the code down.)
>
> Hey, if the compiler does it's job right, I increased the speed of
> something in the kernel. And, as a kernel newbie, I'm proud of that. I
> also did it in under 12 minutes (from time stamp of message received to
> time stamp of message sent after code compiled and diff'd).
Nope you didn't.
Any compiler that can move outline code like
if (con) {
cleanup()
return err;
}
can easily simplify
if (con)
goto err_out;
into a single branch. Still you have enlarged the kernel a bit.
With the same number of jumps, as a rule of thumb, the smaller
code is faster.
Regards
Oliver
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This archive was generated by hypermail 2b29 : Wed Jan 15 2003 - 22:00:42 EST