[En-Nut-Discussion] Extending printf for handling 64 bit values

Ole Reinhardt ole.reinhardt at embedded-it.de
Fri Sep 27 01:12:46 CEST 2013


> As far as I understood, the problem appears only with 64-bit arguments.
> Did I miss something?
> If not, then I think that an increase of 750 bytes for code and 36 bytes
> of RAM is too much for existing programs, which didn't use any 64-bit
> values.

One more argument:

Every int argument is casted to uint64_t, even if you do not use long
long arguments at all.

On an 8 bit CPU, 64 bit calculations (especially divisions) create a BIG
overhead. Lots of wasted CPU cycles.

For reasons of speed it might be a even better idea to use an own
variable for each argument type here!

Best regards,


kernel concepts GmbH            Tel: +49-271-771091-14
Sieghuetter Hauptweg 48         Mob: +49-177-7420433
D-57072 Siegen

More information about the En-Nut-Discussion mailing list