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Re: CASEs compared

From "HAA" <someone@microsoft.com>
Newsgroups comp.lang.forth
Subject Re: CASEs compared
Date 2017-02-05 19:12 +1100
Organization Aioe.org NNTP Server
Message-ID <o76mn7$103o$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><o6ralk$26n$1@gioia.aioe.org><c11c660a-9699-423a-abce-9aaf0ae48b6a@googlegroups.com><3ba54b8a-380a-4fc5-84d7-80271d7cd313@googlegroups.com><o6v0nr$1id1$1@gioia.aioe.org> <o70kdn$j50$1@dont-email.me><o73bhd$h72$1@gioia.aioe.org> <o73ldb$ava$1@dont-email.me><o74f31$1sao$1@gioia.aioe.org> <o74u57$68a$1@dont-email.me>

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rickman wrote:
> On 2/4/2017 6:50 AM, HAA wrote:
> > rickman wrote:
> >> ...
> >> Without wading through the assembly code, I can't see how the simple
> >> changes you made would cause such large changes in the assembly code.
> >> The part that recurs three times is one Forth word shorter.  The two
> >> parts that are used once are one Forth word longer.  Any ideas?
> >>
> >> Looks to me that VFX is doing some great optimizations for TEST1 while
> >> doing virtually nothing for TEST2.  What this is showing is not the
> >> difference in the two examples, but the difference in how VFX treats them.
> >
> > You would have to ask MPE but my guess is once you spill to the return stack
> > there's less interest to optimize as the return stack is supposed to be for
> > temporary storage.
>
> "Less interest"???  Optimization is optimization.  Look at the assembly
> generated.  It is horribly suboptimal with moves from the stack cache
> register to the data stack, then move from the return stack to register,
> registers getting clobbered and reloaded a few instructions later.  This
> isn't code looking for optimization, this is just poor code generation.

I'm not MPE.  You asked for an 'idea' as to what might be going on and
I gave it.  If it's facts you want ask MPE keeping in mind the disassembly
represents an old version of VFX as I stated.

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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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