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Re: CASEs compared

From "HAA" <someone@microsoft.com>
Newsgroups comp.lang.forth
Subject Re: CASEs compared
Date 2017-02-01 11:39 +1100
Organization Aioe.org NNTP Server
Message-ID <o6ralk$26n$1@gioia.aioe.org> (permalink)
References <o6n8ad$191s$1@gioia.aioe.org> <2017Jan30.165616@mips.complang.tuwien.ac.at><097d4d65-5777-4dae-b1b8-6210d2807fc4@googlegroups.com> <o6p01r$3sb$2@gioia.aioe.org> <fb35470d-27ba-4bc2-8ad6-e05404cd2b79@googlegroups.com>

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hughaguilar96@gmail.com wrote:
> On Monday, January 30, 2017 at 8:24:56 PM UTC-7, HAA wrote:
> > hughaguilar96@gmail.com wrote:
> > > ...
> > > Why did he use a linked list? Why not a self-balancing binary-tree? Most likely,
> > > because he didn't know how to implement a self-balancing binary-tree.
> >
> > Or such effort couldn't be justified on the grounds it would waste resources
> > for no material gain.
>
> Didn't you previously say that his linked-list code was 10 times slower than Eaker's
> CASE construct? But now you say that there would be "no material gain" from using a
> self-balancing binary-tree. hmmm...

Nor can anyone claim there would be material gain unless the speed of the case/switch
was critical to the application.  I accept it wasn't the best Case with which to compare
Eaker but it was all I had at the time and I was curious myself what would be the result.

I've since created a third test which attempts to emulate the run-time of a table-based
C switch of the early 1990's.  It's hand-coded asm to give the best shot at speed.
To use, append it the code I previously posted.

code (exec) ( x table )
  mov   eax, 0 [ebp]
  add   ebp, # 4
  mov   ecx, 0 [ebx]
  mov   edx, ecx
L$1:
  add   ebx, # 4
  cmp   ax, 0 [ebx]
  jz    L$2
  dec   ecx   jnz   L$1  \ faster than loop
\  loop  L$1
  inc   edx  \ default
L$2:
  shl   edx, # 2
  add   edx, ebx
  mov   ebx, 0 [ebp]
  add   ebp, # 4
  jmp   0 [edx]
  next,
end-code

: default ." no match" ;

create TABLE
  10 ,
  0 , 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ,
  ' noop , ' noop , ' noop , ' noop , ' noop ,
  ' noop , ' noop , ' noop , ' noop , ' noop ,
  ' default ,

: test3  cr ." TABLE SWITCH - "
  Counter  TIMES 0 do  9 table (exec) loop  .timer ;

By 2000, Borland's 32-bit Win compiler had thrown out tables for anything that required
comparison.  It used an approach similar to Eaker with the exception that target values
were sorted into smaller groups of a few each for comparison.  The conclusion being
that when down to a few values to compare (which in my experience is most of the time)
a direct compare and branch is best.

> BTW: If this is Rick van Norman, who later got hired by Elizabeth Rather to write
> SwiftForth for her, then I find it highly humorous that his SWITCH was 10 times slower
> than Eaker's CASE
> ...

SwitfForth needed an extensible Case for internal reasons as imagine would VFX.
Both have Eaker of course.

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Thread

CASEs compared "HAA" <someone@microsoft.com> - 2017-01-30 22:34 +1100
  Re: CASEs compared anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-01-30 15:56 +0000
    Re: CASEs compared hughaguilar96@gmail.com - 2017-01-30 09:57 -0800
      Re: CASEs compared "HAA" <someone@microsoft.com> - 2017-01-31 14:26 +1100
        Re: CASEs compared hughaguilar96@gmail.com - 2017-01-31 08:12 -0800
          Re: CASEs compared "HAA" <someone@microsoft.com> - 2017-02-01 11:39 +1100
            Re: CASEs compared hughaguilar96@gmail.com - 2017-01-31 22:37 -0800
              Re: CASEs compared hughaguilar96@gmail.com - 2017-02-01 12:26 -0800
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-01 16:50 -0800
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-01 18:02 -0800
                Re: CASEs compared "HAA" <someone@microsoft.com> - 2017-02-02 21:12 +1100
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-02 13:46 -0800
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-02 17:01 -0800
                Re: CASEs compared "HAA" <someone@microsoft.com> - 2017-02-04 12:43 +1100
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-03 17:52 -0800
                Re: CASEs compared Alex <alex@rivadpm.com> - 2017-02-04 11:10 +0000
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-02 19:57 -0500
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-02 17:05 -0800
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-02 21:55 -0500
                Re: CASEs compared Mark Wills <markwills1970@gmail.com> - 2017-02-03 02:11 -0800
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-03 10:52 -0800
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-03 17:38 -0800
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-03 22:08 -0500
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-03 21:40 -0800
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-04 01:16 -0500
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-03 14:40 -0500
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-03 17:47 -0800
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-03 22:04 -0500
                Re: CASEs compared "HAA" <someone@microsoft.com> - 2017-02-04 12:39 +1100
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-03 23:32 -0500
                Re: CASEs compared "HAA" <someone@microsoft.com> - 2017-02-04 22:50 +1100
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-04 11:07 -0500
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-04 08:48 -0800
                Re: CASEs compared Mark Wills <markwills1970@gmail.com> - 2017-02-04 10:01 -0800
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-04 16:43 -0500
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-04 18:53 -0800
                Re: CASEs compared "HAA" <someone@microsoft.com> - 2017-02-05 19:12 +1100
    Re: CASEs compared "HAA" <someone@microsoft.com> - 2017-01-31 14:25 +1100
  Re: CASEs compared Elliott Chapin <elliott.chapin@gmail.com> - 2017-02-05 08:25 -0800
    Re: CASEs compared Coos Haak <htrofhc@gmail.com> - 2017-02-06 00:42 +0100
  Re: CASEs compared jacko <jackokring@gmail.com> - 2017-02-16 17:46 -0800
    Re: CASEs compared hughaguilar96@gmail.com - 2017-02-17 09:09 -0800

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