[U-Boot] [RFC PATCH] SPL: replace ctype implementation with tiny version

[Tom Rini]

On Sun, Jan 22, 2017 at 11:30:04PM +0000, André Przywara wrote:
> On 22/01/17 16:09, Tom Rini wrote:
> > On Fri, Jan 20, 2017 at 10:33:28PM +0000, Andre Przywara wrote:
> >> The ctype implementation (isdigit() & friends) works with an array of
> >> 256 Bytes - one for each character. This is pretty big in SPL terms,
> >> so let's replace this "bloated" implementation with a tiny version
> >> using C statements. This only implements the functions that the SPL
> >> requires and confines this change only to an actual SPL build.
> >> Saves about 200 Bytes from the SPL code size.
> >>
> >> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> >> ---
> >> Hi,
> >>
> >> some people voiced concerns about running out of SPL code space when
> >> adding new features. In this particular case this was an issue when
> >> looking at the SPL FIT extension series[1].
> >> This patch here on top of this series saves more space than the SPL FIT
> >> series consumed, so I trade this as a bait to people wrestling with this
> >> problem ;-)
> > 
> > So.. where might this fail?
> 
> What do you mean by that?
> 
> > Also, this doesn't look like it comes from
> > the kernel exactly, so "linux/tiny_ctype.h" doesn't seem right (and, is
> > missing the license boilerplate).  It does bear some resemblance to the
> > kernel ctype header so it would of course be correct to attribute that
> > in the boilerplate.
> 
> Actually I quickly hacked that up while looking at the existing map,
> trying to convert it into statements. It was mostly an experiment to see
> if that gives me something (hence the RFC tag).
> 
> If the general idea is acceptable, I can surely make this pretty.

Let me answer both parts at once.  If this is as functional in all
cases, why not just always do this instead?

-- 
Tom
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