I’ve tried __attribute__((optimize(“O2”))) and __attribute__((optimize((2))). All didn’t work.
Chaoran
> On Dec 22, 2014, at 3:39 PM, Oleg Endo <oleg.endo@xxxxxxxxxxx> wrote:
>
> On Mon, 2014-12-22 at 15:33 -0600, Chaoran Yang wrote:
>> Hi all,
>>
>> I’m trying to use the __attribute__((optimize(“-O2”))) to mark a
>> function that should always be optimized. But it doesn’t seem to work.
>> I’ve tested both GCC 4.9.2 and 4.8.3, they both silently ignored the
>> attribute. I’m wondering if I’m something super stupid that I’m not
>> aware of.
>
> Try __attribute__((optimize("O2"))
>
> i.e. remove the leading '-'.
>
> See also:
> https://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function-Attributes
>
> "Strings that begin with O are assumed to be an optimization option,
> while other options are assumed to be used with a -f prefix. "
>
> Cheers,
> Oleg
>
>
