Re: well formed flag ?

From	"Ed" <invalid@nospam.com>
Newsgroups	comp.lang.forth
Subject	Re: well formed flag ?
Date	2012-10-29 23:46 +1100
Organization	Aioe.org NNTP Server
Message-ID	<k6ltvl$gfk$1@speranza.aioe.org> (permalink)
References	<2012102715594849117-chrishinsley@gmailcom> <k6hsut$8ud$1@speranza.aioe.org> <508d1b70.6381688@192.168.0.50> <1538109.deQg0ZcWqx@sunwukong.fritz.box>

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Bernd Paysan wrote:
> Stephen Pelc wrote:
> > The important comparison is the number of hours spent on the
> > code generators for C and Forth.
>
> IMHO VFX is limited on x86 by the numbers of registers.  As are C
> compilers.  When I wrote my Wurstkessel cryptography core, Marcel did
> compare the C compiler result with iForth on x64, where more registers
> are available, and the speed was about the same.

How many C compilers were tested?

> On x86, Andy Glew (one of the designers of the Pentium Pro) suggested
> adding an instruction for "well formed flags" in the Forth sense - which
> could be used for bit-wise operations.  It got turned down by senior
> management, because C compilers couldn't make any benefit from it;
> though assembly code would.
>
> Later, in the SSE instruction set, the idea was revived, and indeed
> implemented: SSE compares store their result flags as either all bits
> set or all bits cleared in the destination register.

I expect C (and similar languages) to generate better code, more easily,
because they operate at a higher level of abstraction than does Forth.
Unlike other languages, Forth is (as you point out) highly reliant on registers
and optimizers.  It needs these to eliminate the inefficiency of pushing items
around a virtual stack - something which conventional cpu's were never
designed to do.

Thread

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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