Re: Fwd: Telecom Clock Driver for MPCBL0010 ATCA computer blade

[Jesper Juhl]

On 10/14/05, Greg KH <greg@xxxxxxxxx> wrote:
> On Fri, Oct 14, 2005 at 12:47:21AM +0200, Jesper Juhl wrote:
> > Ick, no, that's a mess.  Stick with the original version.
> >
> >Don't call functions within a if() statement, it's harder to read.
> direct to me only?  What about everyone on the list?
>
Whoops, wrong button - sorry.  Let's copy LKML.


> > I guess you are right - it /would/ save a variable though ;)
>
> Not worth it.  Ease of maintainability, which means being able to read
> the code better, trumps a single variable on a slow path.
>

Hmm, yeah, I can see the sense in that - if it's not performance
critical, better make it readable.


> > > > +     unsigned long tmp;
> > > > +     unsigned char val;
> > > > +     unsigned long flags;
> > > > +
> > > > +     sscanf(buf, "%lX", &tmp);
> > > > +     dev_dbg(d, "tmp = 0x%lX\n", tmp);
> > > > +
> > > > +     val = (unsigned char)tmp;
> > > >
> > > > You do this a lot, I'm wondering why you don't read directly into
> > > > "val" and then get rid of the "tmp" variable?
> > >
> > > Because you want to cast it.
> > >
> > Ok, I'm feeling a little dense tonight, so bear with me please, but
> > wouldn't the effect of reading into the unsigned char (and potentially
> > getting the value truncated) result in the same thing as casting it
> > later?
>
> I don't think it would be the same if you put a large value in the
> string.  Try it out and see.
>
Ok, I must admit I haven't actually tested it, perhaps I will tomorrow
after I get some sleep.


--
Jesper Juhl <jesper.juhl@xxxxxxxxx>
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