Re: Linux 2.4.10-pre11 -- __builtin_expect

James Antill
2001-09-27T15:41:26Z

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
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