Interprocedural optimization question

[Ramon Bertran Monfort]

Hi,

Does gcc apply inter-procedural optimizations across functions called using 
a function pointer? I guess that gcc performs conservatively assuming that 
the pointer could point everywhere because the pointer is a declared as a 
global variable and could be changed in any place. Is it true?
In this case, is there any pragma or directive to give a hint to the 
compiler, giving the set of possible values of the pointer  (which in my 
case is known by the developer)? If not, this could be useful for 
optimization purposes.

thanks in advance, 

Salut!

Ramon.


-- 
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Ramon Bertran Monfort Departament d'Arquitectura de Computadors
Telefon (+34) 93 4054033/54055 Universitat Politecnica de Catalunya
Fax (+34) 93 4017055Despatx C6-103/C6-221-9 Campus Nord
e-mail [EMAIL PROTECTED]C. Jordi Girona 1-3 - 08034 Barcelona
---

A hundred times every day, I remind myself that my inner and outer life depends
on the labors of other men, living and dead, and that I must exert myself in 
order to give in the measure as I have received and am still receiving.
A. Einstein



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Re: Interprocedural optimization question

[Ramon Bertran Monfort]

El Mon, Jan 29, 2007 at 02:28:34PM -0500, Daniel Berlin ens deleit� amb les 
seg�ents paraules:
> On 1/29/07, Razya Ladelsky <[EMAIL PROTECTED]> wrote:
>> Razya Ladelsky/Haifa/IBM wrote on 29/01/2007 13:46:33:
>>
>>> Hi,
>>>
>>> Does gcc apply inter-procedural optimizations across functions called 
>> using 
>>> a function pointer? I guess that gcc performs conservatively assuming 
>> that 
>>> the pointer could point everywhere because the pointer is a declared as 
>> a 
>>> global variable and could be changed in any place. Is it true?
>>
>> Yes. 
>> The callgraph does not include these calls.
> 
> Well, not quite.
> 
> While the callgraph doesn't include them, ipa-pta will come up with a 
> conservatively correct set for them.
> 
> IN the presence of static function pointers, we will come up with a 
> completely accurate set for them unless they escape

ok, I was wondering the possibility to apply ipa optimizations to a 
predefined set of functions called by the same pointer.
Thanks for the explanation. 

Salut!

-- 
---
Ramon Bertran Monfort Departament d'Arquitectura de Computadors
Telefon (+34) 93 4054033/54055 Universitat Politecnica de Catalunya
Fax (+34) 93 4017055Despatx C6-103/C6-221-9 Campus Nord
e-mail [EMAIL PROTECTED]C. Jordi Girona 1-3 - 08034 Barcelona
---

A hundred times every day, I remind myself that my inner and outer life depends
on the labors of other men, living and dead, and that I must exert myself in 
order to give in the measure as I have received and am still receiving.
A. Einstein



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