Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.forth > #60518
| From | rickman <gnuarm@gmail.com> |
|---|---|
| Newsgroups | comp.lang.forth |
| Subject | Re: Heap's algorithm |
| Date | 2017-06-09 13:43 -0400 |
| Organization | A noiseless patient Spider |
| Message-ID | <ohemhq$dum$1@dont-email.me> (permalink) |
| References | (2 earlier) <774d2d0e-81f4-4219-a17d-858494f100a1@googlegroups.com> <7931b062-2ae1-4810-a14b-c29cf7721dd8@googlegroups.com> <2fc231bf-4c5a-45fd-9718-ced9d9c65238@googlegroups.com> <ohee0q$el2$1@dont-email.me> <31bae73b-2d31-492c-85b5-adc515259fb0@googlegroups.com> |
Julian Fondren wrote on 6/9/2017 11:42 AM:
> On Friday, June 9, 2017 at 10:18:10 AM UTC-5, rickman wrote:
>> : switch ( a1 a2 -- ) >R >R ROVER @ RDUP ! @ ! ;
>
> Does this actually work? It looks like it sets both addresses to the
> same value instead of swapping their values. Just look at the
> store/fetch words: @ ! @ ! instead of @ @ ! !
>
> I would think you'd need
>
> : switch ( a1 a2 -- ) >R >R ROVER @ RDUP @ SWAP ! ! ;
>
> Or more neatly:
>
> : switch ( a1 a2 -- ) >R >R RDUP @ ROVER @ ! ! ;
>
> That saves a SWAP , which is also what the locals version saves.
Let's try it one instruction at a time...
: switch ( a1 a2 -- ) >R >R ROVER @ RDUP ! @ ! ;
( a1 a2 -- ) (R: -- ) ( a1:x1 a2:x2 )
>R ( a1 a2 -- a1 ) (R: -- a2 ) ( a1:x1 a2:x2 )
>R ( -- ) (R: a2 -- a2 a1 ) ( a1:x1 a2:x2 )
ROVER ( -- ) (R: a2 a1 -- a2 a1 a2 ) ( a1:x1 a2:x2 )
@ ( -- x2 ) (R: a2 a1 a2 -- a2 a1 ) ( a1:x1 a2:x2 )
RDUP ( -- x2 ) (R: a2 a1 -- a2 a1 a1 ) ( a1:x1 a2:x2 )
! ( -- ) (R: a2 a1 a1 -- a2 a1 ) ( a1:x2 a2:x2 ) oops!
@
!
;
Yes, your final word looks good.
I've also looked at an addressable stack machine that allows a very small
offset into the stack to retrieve operands which saves a *lot* more stack
juggling. It would require a compiler to be aware of operand positions to
be able to use this effectively. I haven't done much other than to code up
an example app, but it was much more instruction efficient. The variations
on instruction set use between 103 and 60 instructions with the 103 being my
basic stack processor and 60 being the stack indexed instruction set.
The app for this comparison is an interrupt routine for a software DDS which
generates the value to feed a DAC on the fly. Maybe I'll get around to
working on this and produce an FPGA design. I think it could produce
significantly more compact code than a straight stack design. Not sure what
it would take to write an optimizing compiler for it.
--
Rick C
Back to comp.lang.forth | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-08 23:21 -0700
Re: Heap's algorithm Raimond Dragomir <raimond.dragomir@gmail.com> - 2017-06-09 00:27 -0700
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-09 01:40 -0700
Re: Heap's algorithm Raimond Dragomir <raimond.dragomir@gmail.com> - 2017-06-09 02:15 -0700
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-09 03:04 -0700
Re: Heap's algorithm Raimond Dragomir <raimond.dragomir@gmail.com> - 2017-06-09 03:50 -0700
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-09 07:37 -0700
Re: Heap's algorithm Coos Haak <htrofhc@gmail.com> - 2017-06-09 19:50 +0200
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-09 11:32 -0700
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-09 07:54 -0700
Re: Heap's algorithm Andrew Haley <andrew29@littlepinkcloud.invalid> - 2017-06-09 10:11 -0500
Re: Heap's algorithm Alex <alex@rivadpm.com> - 2017-06-09 18:43 +0100
Re: Heap's algorithm rickman <gnuarm@gmail.com> - 2017-06-09 11:18 -0400
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-09 08:42 -0700
Re: Heap's algorithm rickman <gnuarm@gmail.com> - 2017-06-09 13:43 -0400
Re: Heap's algorithm Lars Brinkhoff <lars.spam@nocrew.org> - 2017-06-09 13:08 +0200
Re: Heap's algorithm hughaguilar96@gmail.com - 2017-06-09 09:35 -0700
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-09 23:31 -0700
Re: Heap's algorithm hughaguilar96@gmail.com - 2017-06-10 14:28 -0700
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-10 14:44 -0700
Re: Heap's algorithm hughaguilar96@gmail.com - 2017-06-10 18:56 -0700
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-10 19:19 -0700
Re: Heap's algorithm hughaguilar96@gmail.com - 2017-06-10 21:04 -0700
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-10 21:08 -0700
Re: Heap's algorithm Ron Aaron <rambamist@gmail.com> - 2017-06-11 07:19 +0300
Re: Heap's algorithm Alex <alex@rivadpm.com> - 2017-06-11 09:43 +0100
Re: Heap's algorithm minforth@arcor.de - 2017-06-11 02:35 -0700
Re: Heap's algorithm Alex <alex@rivadpm.com> - 2017-06-11 10:45 +0100
Re: Heap's algorithm rickman <gnuarm@gmail.com> - 2017-06-11 12:32 -0400
Re: Heap's algorithm Alex <alex@rivadpm.com> - 2017-06-11 17:52 +0100
Re: Heap's algorithm rickman <gnuarm@gmail.com> - 2017-06-12 23:26 -0400
Re: Heap's algorithm hughaguilar96@gmail.com - 2017-06-12 19:55 -0700
Re: Heap's algorithm krishna.myneni@ccreweb.org - 2017-06-11 14:40 -0700
Re: Heap's algorithm hughaguilar96@gmail.com - 2017-06-12 09:02 -0700
Re: Heap's algorithm hughaguilar96@gmail.com - 2017-06-10 21:30 -0700
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-10 21:51 -0700
Re: Heap's algorithm "Robert L." <No_spamming@noWhere_7073.org> - 2017-06-12 02:24 +0000
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-11 19:28 -0700
Re: Heap's algorithm Melzzzzz <Melzzzzz@zzzzz.com> - 2017-06-12 03:41 +0000
Re: Heap's algorithm hughaguilar96@gmail.com - 2017-06-14 22:15 -0700
Re: Heap's algorithm Ron Aaron <rambamist@gmail.com> - 2017-06-15 08:29 +0300
Re: Heap's algorithm Alex <alex@rivadpm.com> - 2017-06-15 12:24 +0100
Re: Heap's algorithm Ron Aaron <rambamist@gmail.com> - 2017-06-15 15:59 +0300
Re: Heap's algorithm hughaguilar96@gmail.com - 2017-06-16 01:25 -0700
Re: Heap's algorithm awegel@arcor.de (Alexander Wegel) - 2017-06-15 14:08 +0200
Re: Heap's algorithm hughaguilar96@gmail.com - 2017-06-16 10:46 -0700
Re: Heap's algorithm awegel@arcor.de (Alexander Wegel) - 2017-06-17 02:47 +0200
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-09 00:31 -0700
Re: Heap's algorithm Coos Haak <htrofhc@gmail.com> - 2017-06-09 12:32 +0200
Re: Heap's algorithm hum9 <obi65537@gmail.com> - 2017-06-09 10:03 -0700
Re: Heap's algorithm hum9 <obi65537@gmail.com> - 2017-06-09 22:28 -0700
Re: Heap's algorithm hum9 <obi65537@gmail.com> - 2017-06-10 03:07 -0700
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-10 05:41 -0700
Re: Heap's algorithm hum9 <obi65537@gmail.com> - 2017-06-10 18:05 +0300
Re: Heap's algorithm "Robert L." <No_spamming@noWhere_7073.org> - 2017-06-12 03:32 +0000
Re: Heap's algorithm "Robert L." <No_spamming@noWhere_7073.org> - 2017-06-12 03:35 +0000
Re: Heap's algorithm "Robert L." <No_spamming@noWhere_7073.org> - 2017-06-12 04:01 +0000
Re: Heap's algorithm "Robert L." <No_spamming@noWhere_7073.org> - 2017-06-12 11:01 +0000
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-11 21:14 -0700
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-11 22:00 -0700
Re: Heap's algorithm Melzzzzz <Melzzzzz@zzzzz.com> - 2017-06-12 07:54 +0000
Re: Heap's algorithm Julian Fondren <julian.fondren@gmail.com> - 2017-06-12 01:13 -0700
Re: Heap's algorithm Melzzzzz <Melzzzzz@zzzzz.com> - 2017-06-12 08:20 +0000
Re: Heap's algorithm Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2017-06-14 20:17 +0100
Re: Heap's algorithm hughaguilar96@gmail.com - 2017-06-16 01:16 -0700
Re: Heap's algorithm Alex <alex@rivadpm.com> - 2017-06-16 15:14 +0100
Re: Heap's algorithm Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2017-06-16 20:15 +0100
Re: Heap's algorithm Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2017-06-16 20:14 +0100
Re: Heap's algorithm hughaguilar96@gmail.com - 2017-06-16 19:35 -0700
csiph-web