Re: [PATCH] dir.c: avoid c99 array initialization

[Johannes Schindelin <Johannes.Schindelin@xxxxxx>]

Hi,

On Thu, 28 Aug 2008, Shawn O. Pearce wrote:

> Alex Riesen <raa.lkml@xxxxxxxxx> wrote:
> > 
> > For just these 5 values it is likely more effective to just use
> > a conditional statement (less stack requested, less likely
> > some stupid compiler tries to optimize it wrongly).
> > And just as readable.
> > 
> > diff --git a/dir.c b/dir.c
> > index 92452eb..1cf5985 100644
> > --- a/dir.c
> > +++ b/dir.c
> > @@ -680,17 +680,12 @@ static int cmp_name(const void *p1, const void *p2)
> >   */
> >  static int simple_length(const char *match)
> >  {
> > -	const char special[256] = {
> > -		[0] = 1, ['?'] = 1,
> > -		['\\'] = 1, ['*'] = 1,
> > -		['['] = 1
> > -	};
> >  	int len = -1;
> > 
> >  	for (;;) {
> >  		unsigned char c = *match++;
> >  		len++;
> > -		if (special[c])
> > +		if (!c || '?' == c || '\\' == c || '*' == c || '[' == c)
> 
> I am reminded of a year old thread with my patch to this:
> 
>   http://kerneltrap.org/mailarchive/git/2007/4/15/243541
> 
> The patch never applied.  I wonder why.  Was it just Dscho's comment?

If it was, I am very sorry.

But I still think that a lookup for something that is called potentially a 
million times per second is better than a switch statement (except when 
there are less than, say, 4 cases).

Ciao,
Dscho

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