Re: Interprocedural optimization question

[Ramon Bertran Monfort <rbertran at ac dot upc dot edu>]

El Mon, Jan 29, 2007 at 02:28:34PM -0500, Daniel Berlin ens deleità amb les següents paraules:
> On 1/29/07, Razya Ladelsky <RAZYA@il.ibm.com> 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!

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Ramon Bertran Monfort                 Departament d'Arquitectura de Computadors
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