O flags

Robert Mijakovic mijakovi@in.tum.de
Mon May 25 05:52:00 GMT 2015

Hi Segher,

Thank you for your answer. I have overlooked it while I have checked the 
I have expected to see something like that as optimizations are usually 
applied in multiple
passes and there are dependencies between them. On the other hand, I 
have expected to
see a way to specify multiple passes and all optimizations to be exposed 
to users.

Best regards,

On 24.05.2015 20:46, Segher Boessenkool wrote:
> On Sun, May 24, 2015 at 08:15:46PM +0200, Robert Mijakovic wrote:
>> I took optimizations enabled by O[1..3] and tried to enable them all at
>> once without calling
>> O flag levels. I have found out that improvements I got by using all
>> flags used by the
>> particular O flag level are not even close to what I would get by
>> explicitly using O flag levels.
> That is a frequently asked question:
> http://gcc.gnu.org/wiki/FAQ#optimization-options
> Segher

Robert Mijakovic, Doktorand
Technische Universitaet Muenchen
Institut fuer Informatik, I10
Boltzmannstr. 3
D-85748 Garching
Room 01.04.061
Phone: +49 (89) 289 17677
Fax:   +49 (89) 289 17662
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