Ignored optimization command

Jonathan Wakely jwakely.gcc@gmail.com
Sun Feb 24 11:10:00 GMT 2013

On 24 February 2013 00:23, Kirk Liberty wrote:
> Hi all,
> I'm  trying to use g++ to compile a function with optimization O2
> except for one function I want at O3. I'm not having any luck with
> __attribute__ or #pragma. I am using GCC version 4.7.2. With
> __attribute__ I am getting a warning that the directive was ignored,
> and with #pragma I am simply not seeing the speedup expected.

Maybe the optimizer simply doesn't make the code any faster.

> Here's what I've tried.
> bool* getStreamBool(uint64_t num) __attribute__ ((optimize("-O3"))) {...}

I think this should be "O3" or just "3", without the dash.

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