Shouldn’t it be optimized to:
0x0000000000400530 <+0>: mov $0x2,%eax
0x0000000000400535 <+5>: retq
just like I compiled it with "gcc -O2 t.c”?
Anyway, I just want to say that the __attribute__((optimize(“xx”))) doesn’t seem to work. I tried to use __attribute__((optimize(0))) to turn off optimization on certain functions, but also failed.
Thanks,
Chaoran
> On Dec 22, 2014, at 3:48 PM, Oleg Endo <oleg.endo@xxxxxxxxxxx> wrote:
>
> On Mon, 2014-12-22 at 15:43 -0600, Chaoran Yang wrote:
>> I’ve tried __attribute__((optimize(“O2”))) and __attribute__((optimize((2))). All didn’t work.
>
> What do you expect to be optimized away in your example function?
>
> int foo() __attribute__((optimize("O2")));
> int foo()
> {
> return 2;
> }
>
> Cheers,
> Oleg
>
>
