Re: May the numbers speak - supplement

On Fri, 13 Jun 2025 17:47:24 +0000, Paul Rubin wrote:

mhx@iae.nl (mhx) writes:

HMS is three times faster than  dtimescan  and  timestrscan,  while
HMS2 is 3.5 times slower (as expected).

>
Is HMS the one that I posted, and HMS2 the version that's almost the
same?  Why the speed difference: just because of the extra memory
traffic of leaving extra things on the stack?

HSM see below.
HSM2 is from dxf and uses >NUMBER . That is the kitchen sink compared
to '60 * ...' so of course it is much slower with the current
optimization level of iForth.
-marcel
--
----------------------------------------------------------------------
ANEW -timescan
: dtimescan ( addr count -- d )
   over swap + >r >r
   0. r> 0
   begin
      over r@ <
   while
      over c@ ':'
      = if  swap >r s>d d+ #60 1 m*/ r> 0
      else  #10 * over c@ '0' - +
     endif
     swap 1+ swap
   repeat
   -r nip s>d d+ ;
: timestrscan ( addr count -- d )
  1 1 LOCALS| c6 c1 |
  0. 2SWAP
  OVER + 1- ?DO
       I C@ DUP ':' =
       IF  DROP
           c6 #60 * TO c6
           1 TO C1
     ELSE  '0' -  C1 *  C6 M* D+
           #10 TO C1
    ENDIF
  -1 +LOOP ;
variable p
: advance 1 p +! ;
: digit ( -- n ) p @ c@ '0' - advance ;
: 2digit ( -- n ) digit #10 * digit + advance ; \ skips trailing colon
: hms ( a u -- n ) drop p !   2digit #60 * 2digit + #60 * 2digit + ;
: (number) ( adr len -- ud adr' len' )  0. 2swap >number ;
: get ( adr len -- u adr' len' )  (number) rot drop 1 /string ;
: hms2 ( adr len -- h m s)  get get get 2drop ;
: TEST ( --  )
  CR ." \ dtimescan   : " S" 12:34:56" TICKS-RESET dtimescan
     TICKS? UD. ." clock ticks elapsed, " UD.
  CR ." \ timestrscan : " S" 12:34:56" TICKS-RESET timestrscan
     TICKS? UD. ." clock ticks elapsed, " UD.
  CR ." \ HMS         : " S" 12:34:56" TICKS-RESET hms
     TICKS? UD. ." clock ticks elapsed, " .
  CR ." \ HMS2        : " S" 12:34:56" TICKS-RESET hms2
     TICKS? UD. ." clock ticks elapsed, " ROT . SWAP . . ;
  TEST
#2000000 VALUE #iters
CREATE num ," 12:34:56"
: .SECS  MS? #1000000 #iters 3 * */ ." / " . ." ns per iteration." ;
: TEST2 ( --  )
  CR
  CR ." \ dtimescan   : " TIMER-RESET num C@+ #iters 0 ?DO  2DUP
     dtimescan   2DROP  2DUP dtimescan   2DROP 2DUP dtimescan   2DROP
LOOP
     dtimescan        UD.  .SECS
  CR ." \ timestrscan : " TIMER-RESET num C@+ #iters 0 ?DO  2DUP
     timestrscan 2DROP  2DUP timestrscan 2DROP 2DUP timestrscan 2DROP
LOOP
     timestrscan      UD.  .SECS
  CR ." \ HMS         : " TIMER-RESET num C@+ #iters 0 ?DO  2DUP
     hms          DROP  2DUP hms          DROP 2DUP hms          DROP
LOOP
     hms                .  .SECS
  CR ." \ HMS2        : " TIMER-RESET num C@+ #iters 0 ?DO  2DUP
     hms2        3DROP  2DUP hms2        3DROP 2DUP hms2        3DROP
LOOP
     hms2  ROT . SWAP . .  .SECS ;
TEST2