Re: [PATCH] hex <-> int conversion routines.

["H. Peter Anvin" <hpa@zytor.com>]

Followup to:  <200202191902.g1JJ2wx28246@frodo.gams.co.at>
By author:    Bernd Petrovitsch <bernd@gams.at>
In newsgroup: linux.dev.kernel
>
> Jakob Kemi <jakob.kemi@telia.com> wrote:
> >> > +static __inline__ char inthex_nibble(int x)
> >> > +{
> >> > +	const char* digits = "0123456789abcdef";
> >> > +
> >> > +	return digits[x & 0x0f];
> >> > +}
> >>
> >> perhaps better do static const char *digits.
> >GCC doesn't copy const strings, as opposed to other const arrays.
> >So it should be fine as it is. GCC also reuse duplicated strings.
> 
> You could also do
>     return "0123456789abcdef"[x & 0x0f];
> though some will find it bad, ugly, wrong
> or make a file-global
>     static const char digits[] = "0123456789abcdef";
> 

Better yet...

extern const char inthex_digits[];
static __inline__ char inthex_nybble(int x)
{
	return inthex_digits[x & 15];
}

(Nibble = small amount of food; nybble = 4 bits.  It's a pun on
bite/byte.)

	-hpa

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