lkml.org 
[lkml]   [2001]   [Sep]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: Linux 2.4.10-pre11 -- __builtin_expect
From
Date
Andreas Schwab <schwab@suse.de> writes:

> James Antill <james@and.org> writes:
>
> |> unlikely() also needs to be...
> |>
> |> #define unlikely(x) __builtin_expect(!(x), 1)
> |>
> |> ...or...
> |>
> |> #define unlikely(x) __builtin_expect(!!(x), 0)
>
> This is not needed, since only 0 is the likely value and !! does not
> change that.

Yes it is, given the code...

struct blah *ptr = NULL;

if (unlikely(ptr))

...you'll get a warning from gcc because you are implicitly converting
from a pointer to a long.

--
# James Antill -- james@and.org
:0:
* ^From: .*james@and\.org
/dev/null
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:03    [W:0.111 / U:1.756 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site