Re: May the numbers speak

On 12/06/2025 4:48 am, Hans Bezemer wrote:

On 11-06-2025 20:00, dxf wrote:

On 11/06/2025 11:54 pm, LIT wrote:

Let's find out the difference between my
and "Mark Twain" 's approach to the solution
of "parsing 'time string' task". For simplicity
I'll do everything using DX Forth.
>
My solution is:
>
VARIABLE C6
VARIABLE C1
>
: TIMESTRSCAN ( addr count -- d )
  1 C6 !  1 C1 !
  >R >R 0 0 R> R>
  OVER + 1-
  DO
    I C@ DUP 58 =
    IF
      DROP
      C6 @ 60 * C6 !
      1 C1 !
    ELSE
      48 - C1 @ * C6 @ M* D+
      10 C1 !
    THEN
  -1 +LOOP
;

>
Same using stack ops:
>
: TIMESTRSCAN2 ( addr count -- d )
   >R >R  0 0  1 1 ( C6 C1)  R> R>
   OVER + 1- DO
     I C@ DUP 58 = IF  DROP
       DROP  60 * ( C6)  1 ( C1)
     ELSE
       48 -  *  OVER ( C6) >R  UM*  D+  R>  10 ( C1)
     THEN
   -1 +LOOP 2DROP ;
>
12% faster and 20% smaller by my measurement.

 
It's slightly faster than the original on 4tH:
real    0m5,527s
user    0m5,522s
sys    0m0,004s
 
Opcodes: his: 39, yours: 37

To my mind the variables were, if anything, a distraction.
A simple stack comment serving as a reminder achieved the
same thing.