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Groups > comp.lang.forth > #26762
| From | anton@mips.complang.tuwien.ac.at (Anton Ertl) |
|---|---|
| Newsgroups | comp.lang.forth |
| Subject | Re: ?DUP |
| Date | 2013-10-30 12:24 +0000 |
| Organization | Institut fuer Computersprachen, Technische Universitaet Wien |
| Message-ID | <2013Oct30.132431@mips.complang.tuwien.ac.at> (permalink) |
| References | (6 earlier) <GvidnWdxN85RL_PPnZ2dnUVZ_tCdnZ2d@supernews.com> <2013Oct29.125121@mips.complang.tuwien.ac.at> <ur-dnbVptuRbte3PnZ2dnUVZ_vCdnZ2d@supernews.com> <2013Oct30.092213@mips.complang.tuwien.ac.at> <op.w5rnsnfi5zc71u@localhost> |
"Rod Pemberton" <dont_use_email@xnohavenotit.cnm> writes:
>On Wed, 30 Oct 2013 04:22:13 -0400, Anton Ertl
>> c: rot rot ; : rot rot ;
>>
>
>Interesting, but is there really a need for "c:" definition?
>
>I.e., if you're just defining "rot" to be "rot", what's the
>purpose of "c:" ? Symbolic?
C: rot rot ;
says that when COMPILE, processes the xt of rot, it rotates the top
three items on the compile-time representation of the run-time data
stack. Thinking about it again, if we do it right when we perform the
"COMPILE,", we probably don't want these items to be on the data
stack, but elsewhere, so this definition would be something like:
C: rot 3c> rot 3>c ;
I.e., move three items from the internal COMPILE, stack to the data
stack, rotate them, move three items back. If, OTOH, COMPILE, just
Now the compiler knows how to COMPILE, ROT, and since ROT has default
compilation semantics, it also knows how to compile ROT, but it does
not know how to interpret nor EXECUTE ROT. So we add
: rot rot ;
which uses the compilation semantics to create the
execution/interpretation semantics.
>Of course, you could also implement ROT in assembly or C, etc
>as a low-level word.
Would not be any simpler.
>Or, you could use one of many other high-level definitions:
>
>: ROT 2 ROLL ;
>: ROT TUCK 2SWAP DROP ;
>: ROT NUP 2SWAP DROP ;
>: ROT >R SWAP >R 2R> ;
>: ROT >R 2>R R> 2R> ;
>etc...
[...]
>Of course, you really want to pick whatever is fastest,
>or that which optimizes the best, not necessarily that
>which is the shortest.
These all produce the same code in the kind of compiler I am thinking
of (except maybe 2 ROLL, which requires a mechanism that the others
don't need, and which may not be present). The difference is that all
such definitions require more compile time: the definition of ROT has
to be inlined, and each of the words in the definition has to do it's
compile-time thing. And of course, at some point you have to reach a
primitive level; you cannot define both: 2SWAP in terms of ROT and ROT
in terms of 2SWAP.
- anton
--
M. Anton Ertl http://www.complang.tuwien.ac.at/anton/home.html
comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
New standard: http://www.forth200x.org/forth200x.html
EuroForth 2013: http://www.euroforth.org/ef13/
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Floating Point : To Stack or Not To Stack rickman <gnuarm@gmail.com> - 2013-10-14 16:18 -0400
Re: Floating Point : To Stack or Not To Stack "Elizabeth D. Rather" <erather@forth.com> - 2013-10-14 10:34 -1000
Re: Floating Point : To Stack or Not To Stack Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-14 15:41 -0500
Re: Floating Point : To Stack or Not To Stack Paul Rubin <no.email@nospam.invalid> - 2013-10-14 20:32 -0700
Re: Floating Point : To Stack or Not To Stack rickman <gnuarm@gmail.com> - 2013-10-15 17:14 -0400
Re: Floating Point : To Stack or Not To Stack anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-15 16:22 +0000
Re: Floating Point : To Stack or Not To Stack Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-14 15:42 -0500
Re: Floating Point : To Stack or Not To Stack Hans Bezemer <the.beez.speaks@gmail.com> - 2013-10-16 11:16 +0200
Re: Floating Point : To Stack or Not To Stack anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-15 16:09 +0000
Re: Floating Point : To Stack or Not To Stack krishna.myneni@ccreweb.org - 2013-10-15 18:51 -0700
Re: Floating Point : To Stack or Not To Stack Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-16 03:47 -0500
Re: Floating Point : To Stack or Not To Stack anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-16 12:27 +0000
Re: Floating Point : To Stack or Not To Stack rickman <gnuarm@gmail.com> - 2013-10-25 14:20 -0400
Re: Floating Point : To Stack or Not To Stack Paul Rubin <no.email@nospam.invalid> - 2013-10-25 12:08 -0700
Re: Floating Point : To Stack or Not To Stack rickman <gnuarm@gmail.com> - 2013-10-26 02:34 -0400
Re: Floating Point : To Stack or Not To Stack Paul Rubin <no.email@nospam.invalid> - 2013-10-26 00:13 -0700
Re: Floating Point : To Stack or Not To Stack "Elizabeth D. Rather" <erather@forth.com> - 2013-10-25 21:49 -1000
Re: Floating Point : To Stack or Not To Stack Paul Rubin <no.email@nospam.invalid> - 2013-10-26 01:26 -0700
Re: Floating Point : To Stack or Not To Stack Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-26 05:45 -0500
Re: Floating Point : To Stack or Not To Stack anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-26 13:48 +0000
Re: Floating Point : To Stack or Not To Stack Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-26 14:28 -0500
Re: Floating Point : To Stack or Not To Stack anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-27 12:41 +0000
Re: Floating Point : To Stack or Not To Stack Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-27 08:31 -0500
?DUP (was: Floating Point : To Stack or Not To Stack) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-28 15:19 +0000
Re: ?DUP Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-28 13:54 -0500
Re: ?DUP "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-10-28 16:30 -0400
Re: ?DUP "Elizabeth D. Rather" <erather@forth.com> - 2013-10-28 11:11 -1000
Re: ?DUP anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-29 11:51 +0000
Re: ?DUP Bernd Paysan <bernd.paysan@gmx.de> - 2013-10-29 16:48 +0100
Re: ?DUP anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-29 16:10 +0000
Re: ?DUP albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-29 16:24 +0000
Re: ?DUP Bernd Paysan <bernd.paysan@gmx.de> - 2013-10-29 20:00 +0100
Re: ?DUP anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-30 07:44 +0000
Re: ?DUP Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-29 16:29 -0500
Re: ?DUP "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-10-29 18:58 -0400
Re: ?DUP Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-30 03:15 -0500
Re: ?DUP albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-30 01:14 +0000
Re: ?DUP anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-30 08:22 +0000
Re: ?DUP "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-10-30 08:03 -0400
Re: ?DUP anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-30 12:24 +0000
Re: ?DUP Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-30 12:44 -0500
Re: ?DUP "Alex McDonald" <blog@rivadpm.com> - 2013-10-30 22:43 +0000
Re: ?DUP anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-31 12:09 +0000
Re: ?DUP Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-31 12:23 -0500
Re: ?DUP (was: Floating Point : To Stack or Not To Stack) "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-10-28 16:30 -0400
Re: ?DUP "Elizabeth D. Rather" <erather@forth.com> - 2013-10-28 11:16 -1000
Re: ?DUP Bernd Paysan <bernd.paysan@gmx.de> - 2013-10-29 01:58 +0100
Re: ?DUP Stefan Mauerhofer <smauerhofer@androsoft.ch> - 2013-10-28 18:41 -0700
Re: ?DUP Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-29 04:37 -0500
Re: ?DUP m.a.m.hendrix@tue.nl - 2013-10-29 04:27 -0700
Re: ?DUP anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-29 12:51 +0000
Re: Floating Point : To Stack or Not To Stack anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-26 09:45 +0000
Re: Floating Point : To Stack or Not To Stack albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-26 11:30 +0000
Re: Floating Point : To Stack or Not To Stack Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-26 08:05 -0500
Re: Floating Point : To Stack or Not To Stack mhx@iae.nl - 2013-10-26 06:09 -0700
Re: Floating Point : To Stack or Not To Stack "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-10-27 03:01 -0400
Re: Floating Point : To Stack or Not To Stack "Elizabeth D. Rather" <erather@forth.com> - 2013-10-26 22:23 -1000
Re: Floating Point : To Stack or Not To Stack albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-26 09:39 +0000
Re: Floating Point : To Stack or Not To Stack albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-26 09:44 +0000
Re: Floating Point : To Stack or Not To Stack "Ed" <invalid@invalid.com> - 2013-10-18 14:09 +1000
Re: Floating Point : To Stack or Not To Stack "Elizabeth D. Rather" <erather@forth.com> - 2013-10-17 21:21 -1000
Re: Floating Point : To Stack or Not To Stack "Ed" <invalid@invalid.com> - 2013-10-19 12:14 +1000
Re: Floating Point : To Stack or Not To Stack "Elizabeth D. Rather" <erather@forth.com> - 2013-10-18 17:17 -1000
Re: Floating Point : To Stack or Not To Stack Paul Rubin <no.email@nospam.invalid> - 2013-10-19 02:58 -0700
Re: Floating Point : To Stack or Not To Stack "Ed" <invalid@invalid.com> - 2013-10-27 22:33 +1100
Re: Floating Point : To Stack or Not To Stack mhx@iae.nl - 2013-10-27 06:21 -0700
Re: Floating Point : To Stack or Not To Stack "Ed" <invalid@invalid.com> - 2013-10-29 22:40 +1100
Re: Floating Point : To Stack or Not To Stack Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-27 08:23 -0500
Re: Floating Point : To Stack or Not To Stack Stefan Mauerhofer <smauerhofer@androsoft.ch> - 2013-10-28 18:38 -0700
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