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* Optimisation Problem
@ 2011-04-06 12:19 vikramsp
  2011-04-06 19:42 ` Eric Botcazou
  0 siblings, 1 reply; 5+ messages in thread
From: vikramsp @ 2011-04-06 12:19 UTC (permalink / raw)
  To: gcc-bugs


hello there... i am trying my hands on gcc optimisations options.
i tried e.g. -finline-functions, -funroll-loops and the likes but none
worked for me
for ex. i tried -funroll-loops for code
for (int i = 0; i < 3; ++i)
  a[i] = i;

which should unroll like
a[0] = 0
a[1] = 1
a[2] = 2
but it didn't seem to happen. Is this a bug or something?
please help me write good test case or suggest some. i am using gcc
4.1.2. tried 5.4.2 also on rhel5

Best Regards
-- 
View this message in context: http://old.nabble.com/Optimisation-Problem-tp31332686p31332686.html
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^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: Optimisation Problem
  2011-04-06 12:19 Optimisation Problem vikramsp
@ 2011-04-06 19:42 ` Eric Botcazou
  2011-04-07  3:43   ` vikramsp
  0 siblings, 1 reply; 5+ messages in thread
From: Eric Botcazou @ 2011-04-06 19:42 UTC (permalink / raw)
  To: vikramsp; +Cc: gcc-bugs

> hello there... i am trying my hands on gcc optimisations options.
> i tried e.g. -finline-functions, -funroll-loops and the likes but none
> worked for me
> for ex. i tried -funroll-loops for code
> for (int i = 0; i < 3; ++i)
>   a[i] = i;

Try -O -funroll-loops.

-- 
Eric Botcazou


^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: Optimisation Problem
  2011-04-06 19:42 ` Eric Botcazou
@ 2011-04-07  3:43   ` vikramsp
  2011-04-07  6:49     ` Eric Botcazou
  0 siblings, 1 reply; 5+ messages in thread
From: vikramsp @ 2011-04-07  3:43 UTC (permalink / raw)
  To: gcc-bugs


Thanks Eric.
But i wanted to try them indivisually. Is there any method to do so?
Regards - vikramsp

Eric Botcazou-3 wrote:
> 
>> hello there... i am trying my hands on gcc optimisations options.
>> i tried e.g. -finline-functions, -funroll-loops and the likes but none
>> worked for me
>> for ex. i tried -funroll-loops for code
>> for (int i = 0; i < 3; ++i)
>>   a[i] = i;
> 
> Try -O -funroll-loops.
> 
> -- 
> Eric Botcazou
> 
> 

-- 
View this message in context: http://old.nabble.com/Optimisation-Problem-tp31332686p31339223.html
Sent from the gcc - bugs mailing list archive at Nabble.com.


^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: Optimisation Problem
  2011-04-07  3:43   ` vikramsp
@ 2011-04-07  6:49     ` Eric Botcazou
  2011-04-18  6:12       ` vikramsp
  0 siblings, 1 reply; 5+ messages in thread
From: Eric Botcazou @ 2011-04-07  6:49 UTC (permalink / raw)
  To: vikramsp; +Cc: gcc-bugs

> But i wanted to try them indivisually. Is there any method to do so?

The compiler doesn't optimize anything if you don't pass at least -O.

-- 
Eric Botcazou


^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: Optimisation Problem
  2011-04-07  6:49     ` Eric Botcazou
@ 2011-04-18  6:12       ` vikramsp
  0 siblings, 0 replies; 5+ messages in thread
From: vikramsp @ 2011-04-18  6:12 UTC (permalink / raw)
  To: gcc-bugs


Thanks Eric

Eric Botcazou-3 wrote:
> 
>> But i wanted to try them indivisually. Is there any method to do so?
> 
> The compiler doesn't optimize anything if you don't pass at least -O.
> 
> -- 
> Eric Botcazou
> 
> 

-- 
View this message in context: http://old.nabble.com/Optimisation-Problem-tp31332686p31420992.html
Sent from the gcc - bugs mailing list archive at Nabble.com.


^ permalink raw reply	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2011-04-18  6:12 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-04-06 12:19 Optimisation Problem vikramsp
2011-04-06 19:42 ` Eric Botcazou
2011-04-07  3:43   ` vikramsp
2011-04-07  6:49     ` Eric Botcazou
2011-04-18  6:12       ` vikramsp

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