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Re: min-max-sum

From anton@mips.complang.tuwien.ac.at (Anton Ertl)
Subject Re: min-max-sum
Newsgroups comp.lang.forth
References (5 earlier) <2011Sep1.175921@mips.complang.tuwien.ac.at> <GNmdnc45Y-WWA_3TnZ2dnUVZ8sadnZ2d@supernews.com> <TuidnQUKY6X6P_3TnZ2dnUVZ7vednZ2d@supernews.com> <2011Sep2.124104@mips.complang.tuwien.ac.at> <HpWdnb0rJr4bI_3TnZ2dnUVZ8umdnZ2d@supernews.com>
Organization Institut fuer Computersprachen, Technische Universitaet Wien
Date 2011-09-04 13:18 +0000
Message-ID <2011Sep4.151850@mips.complang.tuwien.ac.at> (permalink)

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Andrew Haley <andrew29@littlepinkcloud.invalid> writes:
>At some point you have to say "enough!".  I presume that if you have
>twenty things to aggregate you wouldn't use 20 ROLL .

Assuming that speed is important, I would probably write the
aggregations in a syntax for a code generator that might use a variety
of implementation approaches (including 20 ROLL).  Depending on the
target syntax, the parameters of this code generator would be adjusted
for the best results.  For a sophisticated Forth system on an
architecture with 32 registers or more, the resulting code might
indeed contain a 20 ROLL.

>Yes, but a most useful general rule for programmers is "avoid
>premature optimization."  And in this case, it certainly is premature
>because we have not the slightest idea of what this is going to be
>used for.  We don't know what Forth is going to be used, so we can't
>optimize for it anyway.  As I said several posts ago...

And as I wrote several postings ago, if efficiency is no concern, I
would aggregate each value in a separate loop.

Your suggestion seems to imply that all our discussions should take
the "efficiency is no concern" POV, because everything else is
"premature optimization".  I disagree.  While premature optimization
should be avoided in programming, we should not avoid discussing
optimizations; after all, in such discussions we can work out how to
optimize in those cases where the optimization is not premature.

Anyway, I have now benchmarked the three different approaches on
vfxlin (program appended below):

1) using a separate loop for each aggregation (simple)

2) using one loop and keeping the intermediate results on the data stack (rot)

3) using one loop and keeping the intermediate results in a struct (haley)

The results are:

[c8:~/forth:30521] time vfxlin "include min-max-sum.fs bench-simple bye" >/dev/null

real    0m0.713s
user    0m0.696s
sys     0m0.008s
[c8:~/forth:30522] time vfxlin "include min-max-sum.fs bench-rot bye" >/dev/null 

real    0m0.442s
user    0m0.432s
sys     0m0.008s
[c8:~/forth:30523] time vfxlin "include min-max-sum.fs bench-haley bye" >/dev/null

real    0m2.935s
user    0m2.912s
sys     0m0.008s

Not sure what's so slow in the haley code, but if someone wants to
investigate, the code is shown below.

- anton

: asum ( addr ucells -- n )
    0 rot rot cells over + swap ?do
        i @ +
    [ 1 cells ] literal +loop ;

: amin ( addr ucells -- n )
    $7fffffff rot rot cells over + swap ?do
        i @ min
    [ 1 cells ] literal +loop ;

: amax ( addr ucells -- n )
    $80000000 rot rot cells over + swap ?do
        i @ max
    [ 1 cells ] literal +loop ;

: simple ( addr ucells -- nsum nmax nmin )
    2dup amin >r
    2dup amax >r
    asum r> r> ;

: sum-min-max ( addr ucells -- nsum nmax nmin )
 2>r 0 $80000000 $7fffffff 2r> cells over + swap ?do ( nsum' nmax' nmin' )
  rot i @ +
  rot i @ max
  rot i @ min
 1 cells +loop ;

\ define a struct the VFX way :-)
: f_sum ;
: f_max cell+ ;
: f_min 2 cells + ;

create some-f 3 cells allot

: max! ( n addr -- )
    dup @ rot max swap ! ;

: min! ( n addr -- )
    dup @ rot min swap ! ;
    
: haley ( addr ucells f-addr -- )
    0 over f_sum !
    $80000000 over f_max !
    $7fffffff over f_min !
    rot rot cells over + swap do
        i @ over f_sum +!
        i @ over f_max max!
        i @ over f_min min!
    loop  drop ; 

: bench-simple ( -- )
    100 0 ?do
        here 1000000 simple . . . cr
    loop ;

: bench-rot ( -- )
    100 0 ?do
        here 1000000 sum-min-max . . . cr
    loop ;

: bench-haley ( -- )
    100 0 ?do
        here 1000000 some-f haley
    loop ;

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A Minimal Extended Control Wordset JennyB <jennybrien@googlemail.com> - 2011-08-24 07:01 -0700
  Re: A Minimal Extended Control Wordset JennyB <jennybrien@googlemail.com> - 2011-08-24 07:50 -0700
    Re: A Minimal Extended Control Wordset Alex McDonald <blog@rivadpm.com> - 2011-08-24 08:04 -0700
      Re: A Minimal Extended Control Wordset JennyB <jennybrien@googlemail.com> - 2011-08-24 08:59 -0700
        Re: A Minimal Extended Control Wordset coos haak <chforth@hccnet.nl> - 2011-08-24 20:00 +0200
          Re: A Minimal Extended Control Wordset JennyB <jennybrien@googlemail.com> - 2011-08-24 14:03 -0700
            Re: A Minimal Extended Control Wordset coos haak <chforth@hccnet.nl> - 2011-08-26 20:36 +0200
    Re: A Minimal Extended Control Wordset JennyB <jennybrien@googlemail.com> - 2011-08-24 07:54 -0700
    Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-09-12 09:43 -0700
  Re: A Minimal Extended Control Wordset "Rod Pemberton" <do_not_have@noavailemail.cmm> - 2011-08-24 18:52 -0400
    Re: A Minimal Extended Control Wordset JennyB <jennybrien@googlemail.com> - 2011-08-25 06:52 -0700
      Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-08-26 12:23 +1000
        Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-08-25 21:03 -0700
          Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-08-26 20:02 +1000
            Re: A Minimal Extended Control Wordset JennyB <jennybrien@googlemail.com> - 2011-08-26 04:36 -0700
              Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-08-26 10:42 -0700
                Re: A Minimal Extended Control Wordset JennyB <jennybrien@googlemail.com> - 2011-08-27 14:45 -0700
                Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-08-27 17:13 -0700
            Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-08-26 10:16 -0700
  Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-08-25 09:46 -0700
    Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-08-25 20:54 -0700
      Re: A Minimal Extended Control Wordset JennyB <jennybrien@googlemail.com> - 2011-08-26 10:24 -0700
        Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-08-26 11:04 -0700
          Re: A Minimal Extended Control Wordset JennyB <jennybrien@googlemail.com> - 2011-08-31 04:14 -0700
            Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-08-31 15:25 -0700
              Re: A Minimal Extended Control Wordset JennyB <jennybrien@googlemail.com> - 2011-09-01 04:00 -0700
                Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-09-01 12:47 -0700
        Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-08-27 13:18 +1000
          Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-08-27 04:41 -0700
            Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-08-28 13:28 +1000
              Re: A Minimal Extended Control Wordset "Elizabeth D. Rather" <erather@forth.com> - 2011-08-27 18:32 -1000
                Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-08-29 12:32 +1000
              Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-08-28 09:22 -0700
                Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-08-29 12:30 +1000
                Re: A Minimal Extended Control Wordset "Elizabeth D. Rather" <erather@forth.com> - 2011-08-28 18:17 -1000
                return address manipulation (was: A Minimal Extended Control Wordset) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2011-08-29 09:14 +0000
                Re: return address manipulation Andrew Haley <andrew29@littlepinkcloud.invalid> - 2011-08-29 05:53 -0500
                Re: return address manipulation anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2011-08-29 11:45 +0000
                Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-08-30 14:08 +1000
                Re: A Minimal Extended Control Wordset "Elizabeth D. Rather" <erather@forth.com> - 2011-08-29 18:28 -1000
                Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-08-31 13:52 +1000
                Re: A Minimal Extended Control Wordset "Elizabeth D. Rather" <erather@forth.com> - 2011-08-30 21:42 -1000
                Re: A Minimal Extended Control Wordset Paul Rubin <no.email@nospam.invalid> - 2011-08-31 00:47 -0700
                Re: A Minimal Extended Control Wordset "Elizabeth D. Rather" <erather@forth.com> - 2011-08-30 21:55 -1000
                Re: A Minimal Extended Control Wordset Paul Rubin <no.email@nospam.invalid> - 2011-09-01 00:44 -0700
                Re: A Minimal Extended Control Wordset Andrew Haley <andrew29@littlepinkcloud.invalid> - 2011-09-01 03:37 -0500
                Re: A Minimal Extended Control Wordset Paul Rubin <no.email@nospam.invalid> - 2011-09-01 02:19 -0700
                Re: A Minimal Extended Control Wordset Andrew Haley <andrew29@littlepinkcloud.invalid> - 2011-09-01 05:05 -0500
                min-max-sum (was: A Minimal Extended Control Wordset) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2011-09-01 14:32 +0000
                Re: min-max-sum Andrew Haley <andrew29@littlepinkcloud.invalid> - 2011-09-01 10:43 -0500
                Re: min-max-sum anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2011-09-01 15:59 +0000
                Re: min-max-sum BruceMcF <agila61@netscape.net> - 2011-09-01 13:13 -0700
                Re: min-max-sum Andrew Haley <andrew29@littlepinkcloud.invalid> - 2011-09-02 04:12 -0500
                Re: min-max-sum Andrew Haley <andrew29@littlepinkcloud.invalid> - 2011-09-02 04:31 -0500
                Re: min-max-sum anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2011-09-02 10:41 +0000
                Re: min-max-sum Andrew Haley <andrew29@littlepinkcloud.invalid> - 2011-09-02 06:31 -0500
                Re: min-max-sum anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2011-09-04 13:18 +0000
                Re: min-max-sum mhx@iae.nl (Marcel Hendrix) - 2011-09-04 22:42 +0200
                Re: min-max-sum anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2011-09-05 08:16 +0000
                Re: min-max-sum Andrew Haley <andrew29@littlepinkcloud.invalid> - 2011-09-05 02:58 -0500
                Re: min-max-sum BruceMcF <agila61@netscape.net> - 2011-09-02 08:43 -0700
                Re: min-max-sum coos haak <chforth@hccnet.nl> - 2011-09-02 20:35 +0200
                Re: min-max-sum BruceMcF <agila61@netscape.net> - 2011-09-03 11:48 -0700
                Re: min-max-sum BruceMcF <agila61@netscape.net> - 2011-09-04 18:31 -0700
                Re: min-max-sum Alex McDonald <blog@rivadpm.com> - 2011-09-02 05:37 -0700
                Re: min-max-sum mhx@iae.nl (Marcel Hendrix) - 2011-09-03 12:06 +0200
                Re: A Minimal Extended Control Wordset Paul Rubin <no.email@nospam.invalid> - 2011-09-04 22:07 -0700
                Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-09-04 22:56 -0700
                Re: A Minimal Extended Control Wordset C G Montgomery <cgm@physics.utoledo.edu> - 2011-09-05 17:44 -0400
                Re: A Minimal Extended Control Wordset Paul Rubin <no.email@nospam.invalid> - 2011-09-05 18:10 -0700
                Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-09-01 11:01 -0700
                Re: A Minimal Extended Control Wordset "Elizabeth D. Rather" <erather@forth.com> - 2011-09-01 09:17 -1000
                Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-09-01 13:39 +1000
                Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-09-01 10:21 -0700
                Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-09-05 12:24 +1000
                Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-09-04 21:11 -0700
                Re: A Minimal Extended Control Wordset Albert van der Horst <albert@spenarnc.xs4all.nl> - 2011-09-06 18:13 +0000
                Re: A Minimal Extended Control Wordset Alex McDonald <blog@rivadpm.com> - 2011-09-06 12:15 -0700
                Re: A Minimal Extended Control Wordset "Elizabeth D. Rather" <erather@forth.com> - 2011-09-06 09:53 -1000
                Re: A Minimal Extended Control Wordset Alex McDonald <blog@rivadpm.com> - 2011-09-06 14:18 -0700
                Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-09-06 17:32 -0700
                Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-09-07 19:43 +1000
                Re: A Minimal Extended Control Wordset Andrew Haley <andrew29@littlepinkcloud.invalid> - 2011-09-07 06:02 -0500
                Re: A Minimal Extended Control Wordset Alex McDonald <blog@rivadpm.com> - 2011-09-07 05:41 -0700
                Re: A Minimal Extended Control Wordset anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2011-09-07 16:00 +0000
                Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-09-09 08:52 +1000
                Re: A Minimal Extended Control Wordset Alex McDonald <blog@rivadpm.com> - 2011-09-08 16:08 -0700
                Re: A Minimal Extended Control Wordset George Hubert <georgeahubert@yahoo.co.uk> - 2011-09-09 04:12 -0700
                Re: A Minimal Extended Control Wordset Albert van der Horst <albert@spenarnc.xs4all.nl> - 2011-09-10 09:09 +0000
                Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-09-11 18:29 +1000
                Re: A Minimal Extended Control Wordset Alex McDonald <blog@rivadpm.com> - 2011-09-11 09:04 -0700
                Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-09-15 19:25 +1000
                Re: A Minimal Extended Control Wordset Alex McDonald <blog@rivadpm.com> - 2011-09-15 03:30 -0700
                Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-09-18 15:43 +1000
                Re: A Minimal Extended Control Wordset "Elizabeth D. Rather" <erather@forth.com> - 2011-09-17 20:42 -1000
                Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-09-19 05:14 +1000
                Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-09-18 19:31 -0700
                Re: A Minimal Extended Control Wordset Andrew Haley <andrew29@littlepinkcloud.invalid> - 2011-09-18 01:49 -0500
                Re: A Minimal Extended Control Wordset "Elizabeth D. Rather" <erather@forth.com> - 2011-09-08 14:56 -1000
                Re: A Minimal Extended Control Wordset anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2011-09-09 08:20 +0000
                Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-09-11 16:22 +1000
                Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-09-11 03:06 -0700
                Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-09-08 19:29 -0700
                Re: A Minimal Extended Control Wordset Brad <hwfwguy@gmail.com> - 2011-09-08 08:58 -0700
                Re: A Minimal Extended Control Wordset Alex McDonald <blog@rivadpm.com> - 2011-09-08 10:00 -0700
                Re: A Minimal Extended Control Wordset coos haak <chforth@hccnet.nl> - 2011-09-08 22:00 +0200
                Re: A Minimal Extended Control Wordset Alex McDonald <blog@rivadpm.com> - 2011-09-08 16:02 -0700
                Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-09-09 09:16 +1000
                Re: A Minimal Extended Control Wordset "Elizabeth D. Rather" <erather@forth.com> - 2011-09-08 15:04 -1000
                Re: A Minimal Extended Control Wordset Andrew Haley <andrew29@littlepinkcloud.invalid> - 2011-09-09 04:13 -0500
                Re: A Minimal Extended Control Wordset Brad <hwfwguy@gmail.com> - 2011-08-31 09:20 -0700
                Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-08-28 21:31 -0700
                Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-08-31 13:53 +1000
                Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-08-31 04:11 -0700
                Re: A Minimal Extended Control Wordset "Ed" <nospam@invalid.com> - 2011-09-01 14:47 +1000
                Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-09-01 10:32 -0700
                Re: A Minimal Extended Control Wordset BruceMcF <agila61@netscape.net> - 2011-09-01 10:33 -0700

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