On Thu, Dec 28, 2000 at 03:37:51PM -0800, Linus Torvalds wrote:
>
>
> On Fri, 29 Dec 2000, Andi Kleen wrote:
> >
> > Hopefully all the "goto out" micro optimizations can be taken out then too,
>
> "goto out" often generates much more readable code, so the optimization is
> secondary.
I was more thinking of cases like the scheduler's gotos, which has gotten
rather spagetti recently. Admittedly classic goto out is often more readable
than many nested if()s with error handling.
>
> > I recently found out that gcc 2.97's block moving pass has the tendency
> > to move the outlined blocks inline again ;)
>
> Too bad. Maybe somebody should tell gcc maintainers about programmers that
> know more than the compiler again.
In x86-64 which relies on 2.97 I'm using __builtin_expect, defined to
likely() and unlikely(), which seems to generate good code.
-Andi
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
Please read the FAQ at http://www.tux.org/lkml/
