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Re: well formed flag ?

From Chris Hinsley <chris.hinsley@gmail.com>
Newsgroups comp.lang.forth
Date 2012-10-27 16:03 +0100
Message-ID <201210271603106615-chrishinsley@gmailcom> (permalink)
References <2012102715594849117-chrishinsley@gmailcom>
Subject Re: well formed flag ?

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On 2012-10-27 14:59:48 +0000, Chris Hinsley said:

> Folks, I'm doing some tweaking to my hobby Forth compiler and just been 
> doing some inlineing work.
> 
> I'm not very happy about the size of the x86 code for comparision words 
> (I know I could reduce the code size if I had a full optimizing code 
> generator, but I don't yet…) this is my code for "<"
> 
> 	defword ">", 0, WORD_GT, WORD_INLINE_COMMA
> 	POPDSP eax
> 	cmp eax, ebx
> 	setg bl
> 	movzx ebx, bl
> 	neg ebx
> 	ret
> 	defword_end
> 
> I followed the 'well formed flag' comments in Ms Rathers book for this, 
> but the IF and TRUE, FALSE words only talk about 0 for false or not 
> zero for true. Is it definately the case that Forth needs -1 to come 
> from the comparason words ?
> 
> Are you allowed to write code that _needs_ the -1 from the ">" ? ie if 
> it produce just a 1, would that be incorrect ?
> 
> Chris

I might also add that my 0BRANCH word is:

	defword "0BRANCH", 0, WORD_ZBRANCH, WORD_INLINE_COMMA
	mov eax, ebx
	POPDSP ebx
	test eax, eax
	jz strict near i_jmp
	ret
	defword_end

Regards

Chris

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well formed flag ? Chris Hinsley <chris.hinsley@gmail.com> - 2012-10-27 15:59 +0100
  Re: well formed flag ? Chris Hinsley <chris.hinsley@gmail.com> - 2012-10-27 16:03 +0100
    Re: well formed flag ? Alex McDonald <blog@rivadpm.com> - 2012-10-27 08:33 -0700
      Re: well formed flag ? Alex McDonald <blog@rivadpm.com> - 2012-10-27 09:06 -0700
        Re: well formed flag ? Alex McDonald <blog@rivadpm.com> - 2012-10-27 09:26 -0700
          Re: well formed flag ? Chris Hinsley <chris.hinsley@gmail.com> - 2012-10-27 20:33 +0100
            Re: well formed flag ? Chris Hinsley <chris.hinsley@gmail.com> - 2012-10-27 20:38 +0100
            Re: well formed flag ? Alex McDonald <blog@rivadpm.com> - 2012-10-27 12:52 -0700
              Re: well formed flag ? Chris Hinsley <chris.hinsley@gmail.com> - 2012-10-27 21:01 +0100
                Re: well formed flag ? Coos Haak <chforth@hccnet.nl> - 2012-10-27 22:18 +0200
                Re: well formed flag ? "Rod Pemberton" <do_not_have@notemailnotz.cnm> - 2012-10-28 04:19 -0400
        Re: well formed flag ? Chris Hinsley <chris.hinsley@gmail.com> - 2012-10-27 17:44 +0100
          Re: well formed flag ? "Rod Pemberton" <do_not_have@notemailnotz.cnm> - 2012-10-27 14:52 -0400
            Re: well formed flag ? Chris Hinsley <chris.hinsley@gmail.com> - 2012-10-27 20:06 +0100
        Re: well formed flag ? Chris Hinsley <chris.hinsley@gmail.com> - 2012-10-27 19:25 +0100
          Re: well formed flag ? Chris Hinsley <chris.hinsley@gmail.com> - 2012-10-27 19:33 +0100
          Re: well formed flag ? Alex McDonald <blog@rivadpm.com> - 2012-10-27 15:08 -0700
            Re: well formed flag ? Chris Hinsley <chris.hinsley@gmail.com> - 2012-10-28 00:53 +0100
  Re: well formed flag ? Mark Wills <forthfreak@gmail.com> - 2012-10-27 09:31 -0700
    Re: well formed flag ? "A. K." <akk@nospam.org> - 2012-10-27 19:21 +0200
      Re: well formed flag ? Mark Wills <forthfreak@gmail.com> - 2012-10-27 10:33 -0700
        Re: well formed flag ? Coos Haak <chforth@hccnet.nl> - 2012-10-27 22:21 +0200
        Re: well formed flag ? "Ed" <invalid@nospam.com> - 2012-10-28 12:33 +1100
          Re: well formed flag ? "Elizabeth D. Rather" <erather@forth.com> - 2012-10-27 15:46 -1000
  Re: well formed flag ? "Elizabeth D. Rather" <erather@forth.com> - 2012-10-27 08:54 -1000
    Re: well formed flag ? Chris Hinsley <chris.hinsley@gmail.com> - 2012-10-27 20:11 +0100
  Re: well formed flag ? "Ed" <invalid@nospam.com> - 2012-10-28 11:05 +1100
    Re: well formed flag ? stephenXXX@mpeforth.com (Stephen Pelc) - 2012-10-28 11:53 +0000
      Re: well formed flag ? Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-28 14:17 +0100
        Re: well formed flag ? mhx@iae.nl (Marcel Hendrix) - 2012-10-28 16:59 +0200
          Re: well formed flag ? Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-28 18:37 +0100
        Re: well formed flag ? "Ed" <invalid@nospam.com> - 2012-10-29 23:46 +1100
          Re: well formed flag ? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-10-29 08:33 -0500
            Re: well formed flag ? Paul Rubin <no.email@nospam.invalid> - 2012-10-29 08:25 -0700
              Re: well formed flag ? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-10-29 12:27 -0500
                Re: well formed flag ? Paul Rubin <no.email@nospam.invalid> - 2012-10-30 08:18 -0700
                Re: well formed flag ? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-10-30 10:33 -0500
                Re: well formed flag ? Paul Rubin <no.email@nospam.invalid> - 2012-10-30 08:48 -0700
                Re: well formed flag ? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-10-30 11:45 -0500
                Re: well formed flag ? Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-30 20:10 +0100
                Re: well formed flag ? Alex McDonald <blog@rivadpm.com> - 2012-10-30 15:10 -0700
                Re: well formed flag ? Paul Rubin <no.email@nospam.invalid> - 2012-10-30 18:28 -0700
                Re: well formed flag ? Alex McDonald <blog@rivadpm.com> - 2012-11-02 05:28 -0700
                Re: well formed flag ? Paul Rubin <no.email@nospam.invalid> - 2012-11-02 08:13 -0700
                Re: well formed flag ? "Elizabeth D. Rather" <erather@forth.com> - 2012-10-30 12:50 -1000
                Re: well formed flag ? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-10-31 14:57 +0000
                Re: well formed flag ? Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-31 17:58 +0100
                Re: well formed flag ? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-10-31 17:39 +0000
                Re: well formed flag ? David Thompson <dave.thompson2@verizon.net> - 2012-11-16 23:21 -0500
                Aliasing (was: well formed flag ?) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-10-31 14:03 +0000
                Re: well formed flag ? "Rod Pemberton" <do_not_have@notemailnotz.cnm> - 2012-10-31 12:06 -0400
                Re: well formed flag ? Paul Rubin <no.email@nospam.invalid> - 2012-10-31 09:31 -0700
                Aliases (was: well formed flag ?) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-10-31 17:02 +0000
                Re: well formed flag ? "Rod Pemberton" <do_not_have@notemailnotz.cnm> - 2012-10-31 20:06 -0400
      Re: well formed flag ? "Ed" <invalid@nospam.com> - 2012-10-29 23:47 +1100
        Re: well formed flag ? stephenXXX@mpeforth.com (Stephen Pelc) - 2012-10-30 18:02 +0000
          Re: well formed flag ? "Ed" <invalid@nospam.com> - 2012-10-31 11:44 +1100
            Re: well formed flag ? stephenXXX@mpeforth.com (Stephen Pelc) - 2012-10-31 09:25 +0000

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