Re: PCI Express support for 2.4 kernel

[Vladimir Kondratiev]

OK, I almost convinced it may be removed.
My point is, this initialization with 0 cost nothing. Readability and 
clearness of code do matter, on my opinion. I think when one states 
explicitly he expect variable to have 0 value, it is better then use 
implicit rules.

To illustrate zero cost, I did the following test:
[tmp]$ cat t.c; gcc -S t.c; cat t.s
static int a1=0;
static int a2;
/* EOF */

   .file    "t.c"
   .local    a1
   .comm    a1,4,4
   .local    a2
   .comm    a2,4,4
   .section    .note.GNU-stack,"",@progbits
   .ident    "GCC: (GNU) 3.3.1 20030811 (Red Hat Linux 3.3.1-1)"

As you can see, assembly code is identical, compiler did this trivial 
optimization for me.

Vladimir.

Mark Hahn wrote:

> > > > +static void* rrbar_virt=NULL;
> > > >        
> > > Do not bother initializing static variables to zero.  This just wastes 
> > > bss space, since these variables are automatically zeroed for you, 
> > > anyway.
> > >      
> > I did not found this feature in standard. More, future versions of gcc 
> > will give at least warning, if not error, like "use of uninitialized 
> > variable". Many good sources also say it is good practice to initialize 
> > all variables. I rely on its value later. I' ll keep it as is unless 
> > really strong arguments provided.
> >    
>
> it'll get your code rejected.  static variables are always, everywhere,
> initialized to zero (OK, probably not embedded environments).  this is 
> a code standard, not a matter of taste.
>
>  

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