Changing tag because I think it entered the PIC domain.


Just finished benchmarking my custom PIC18 'printf' against Microchip's
original:

Test code vas:

unsigned long value =3D 1;
while( 1 )
    {
    printf( "%lu", value );
    value *=3D 10;
    }

int _user_putc( char c )
    {
    return 0;
    }


Please note that the function '_user_putc' was "neutralized" just to
remove hardware times from the benchmark. We are testing just the
mathematical portions of the process. Function "_user_putc" is what
ultimately displays each character.


Times for Microchip's original 'printf':

value -> cycles
1 -> 2104
10 -> 3756
100 -> 5440
1,000 -> 7108
10,000 -> 8840
100,000 -> 10556
1,000,000 -> 12288
10,000,000 -> 14036
100,000,000 -> 15800
1,000,000,000 -> 17628


Times for my improved 'printf':

value -> cycles
1 -> 1255
10 -> 1347
100 -> 1621
1,000 -> 1895
10,000 -> 2229
100,000 -> 2503
1,000,000 -> 2777
10,000,000 -> 3111
100,000,000 -> 3385
1,000,000,000 -> 3659


I think my routine is worth sharing but I'm afraid of doing this without
knowing the legal implications, that's why I posted the original question.


Regards,

Isaac



Em 15/2/2012 15:27, Isaac Marino Bavaresco escreveu:
> Dear all,
>
>
> Many should know that Microchip's MPLAB C18 compiler comes with full
> source code of its libraries, even the lite and eval versions.
>
> I made many improvements to said files for my own use. My question is:
> how could I share my improvements with others without breaching
> Microchip's copyright?
>
> I have thought that perhaps I can publish the diffs between my versions
> and Microchip's. Diff files bear a minimum of the original source code
> just to contextualize where the changes are to be inserted. This way, by
> using my diffs alone nobody can retrieve Microchip's source code, he/she
> would need to have already the original source code to apply the patches
> against.
>
> What do you think?
>
>
> Some files I rewrote from scratch. Those I think are safe to share.
>
>
> Best regards,
>
> Isaac
>

--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.