Re: Built-in base2dec and dec2base

[Daniel J Sebald]

> I've done a first pass of built-in versions of base2dec() and
> dec2base(), and I put a patch in the features portion of SourceForge

Carnë informed me I used the wrong tracker.  (Thanks Carnë.)  I moved 
the patch to:

https://savannah.gnu.org/patch/index.php?7825

...

I tested a version of dec2base that uses the C++ library div() routine

http://www.cplusplus.com/reference/clibrary/cstdlib/div/

to generate quotient and remainder at the same time.  Where I thought it 
might cut the computations some, it turns out to be slower than using 
operate divide followed by multiply and subtract.  My guess is that the 
div() routine for some reason doesn't know how to optimize for the 
processor or the CPU doesn't have remainder as part of its div 
instruction.  Consequently it just introduces extra overhead of the 
div_t structure.

COMMAND                      BUILT-IN        BUILT-IN
                             DIVIDE          div_t
                             MULTIPLY           div()
_______                      ________        _______

dec2bin(<int vector>)        0.22697         0.25996
dec2bin(<cell vector>)       0.23996         0.28496
dec2hex(<int vector>)        0.11998         0.12998
dec2hex(<cell vector>)       0.13898         0.16198
dec2base(<int vec>, '01')    0.22497         0.24796
dec2base(<cell vec>, '01')   0.23996         0.28396

Dan