On 07.7.2010 13:22:39, Marek Polacek wrote:
On 07/07/2010 12:58 PM, Maksym Kryzhanovskyy wrote:
> Hi Denis,
>
> can we use the __builtin_expect function in busybox?
> In the previous patch for ifplugd it might be usefull
> (see attachment).
>
>
> Regards.
>
> Max.
>
>
This is optimalization for speed and BB is optimized for size, so we
would not gain too much. In Linux kernel is it quite common though --
along with __builtin_prefetch etc.
BTW: this macro in plain form looks ugly, it is common to define it as
#define unlikely(x) __builtin_expect(!!(x), 0)
#define unlikely(x) __builtin_expect(!!(x), 0)
--
MP
On 07.7.2010 13:34:29, Bernhard Reutner-Fischer wrote:
please use likely() / unlikely() instead.
Hi,
thanks for yours reply. I tried to use the 'macrorized' unlikley() only
for a case when those few extra instruction will be really useful.
BTW: #define _must_ die :-), it's a horror :-( -- sublanguage for each project
.. (of course it's a joke)
Regards.
Max.
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