Re: [PATCH] Decrease number of pointer derefs in nfnetlink_queue.c

[Steven Rostedt <rostedt@goodmis.org>]

On Thu, 2005-12-08 at 14:51 -0800, David S. Miller wrote:
> From: Jesper Juhl <jesper.juhl@gmail.com>
> Date: Thu, 8 Dec 2005 23:36:01 +0100
> 
> > Here's a small patch to decrease the number of pointer derefs in
> > net/netfilter/nfnetlink_queue.c
> > 
> > Benefits of the patch:
> >  - Fewer pointer dereferences should make the code slightly faster.
> >  - Size of generated code is smaller
> >  - improved readability
> 
> And you verified the compiler isn't making these transformations
> already?  It should be doing so via Common Subexpression Elimination
> unless the derefs are scattered around with interspersed function
> calls in which case the compiler cannot prove that the memory
> behind the pointer does not change.

Even if point one and two are not true, if it doesn't hurt size or
performance, point three (improved readability) is definitely worth
adding.

-- Steve


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