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Re: question about allocating local variable


--- Eljay Love-Jensen <eljay@adobe.com> wrote:
> Hi Prawit,
> 
>  >Does anybody has any explaination [why the
> compiler allocates more than 
> specified]?
> 
> Alignment.

If we need char a[9] and the compiler allocated 12
bytes for me. That makes sense. But I'm wondering why
I need 9 bytes but compiler allocated 24 bytes.
I might misunderstand about alignment. And I will be
appreciate if you could tell me why it gonna be that
way.

> 
> You didn't specify what platform, GCC version
> (3.3.4?  3.4.0?), and compile 
> options you are using.  If you are not generated
> optimized code, the code 
> may not be optimized.
> 

gcc 2.96 on x86 And asm code are the same no matter
what you gonna optimized or not.

> It is also possible that one of the GCC Gnurus made
> a boo-boo.  Rare, but 
> can happen.  Especially between optimizations that
> are in contention, which 
> may have unintended side-effects on different
> platforms.  (I discovered 3 
> such issues, on GCC 2.95 on Solaris.  They're all
> fixed now.)
> 
> HTH,
> --Eljay
> 
> 



		
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