Re: printf size requirement

[Anders Lindgren <ali at df dot lth dot se>]

On Mon, 23 Apr 2007, Joel Sherrill wrote:

[snip]
> >   --enable-newlib-reent-small   enable small reentrant struct support
> This looks promising for general RTEMS use since it doesn't sound like it
> disables any functionality.  Any ideas how much difference it makes?  It 
> looks
> pretty substantial.

  Without having actually measured, I don't think it saves you a whole lot 
if your threads actually use libc a lot. It's primary function is to 
postpone allocation of several reentrancy data fields to runtime as 
needed, instead of always including them statically in struct reent. If 
many of your threads only make trivial use of libc however, I guess there 
could be interesting savings.

[snip]
> >   --disable-newlib-atexit-alloc    disable dynamic allocation of atexit
> > entries
> Interesting trade-off but doesn't this limit you to one atexit() per thread?

  AFAIK it only disables dynamic allocation of additional atexit() entries 
beyond the 32 dictated by ANSI C. See e.g.: <sys/reent.h>.

[snip]
> >   --enable-target-optspace  optimize for space

..and this switches from using -O2 to -Os, and makes some libc functions 
simpler, e.g. mem* and str* functions.

Take care,
ali:)