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Groups > comp.lang.forth > #51640
| From | Cecil Bayona <cbayona@cbayona.com> |
|---|---|
| Newsgroups | comp.lang.forth |
| Subject | Re: Stack Sizes |
| Date | 2016-10-05 20:49 -0500 |
| Organization | A noiseless patient Spider |
| Message-ID | <nt4aic$jf6$1@dont-email.me> (permalink) |
| References | (5 earlier) <nt3cjs$rh7$1@dont-email.me> <nt3mih$1k3$1@dont-email.me> <nt3p33$aqp$1@dont-email.me> <nt3rp4$im7$1@dont-email.me> <f5ydnWENyNXcAmjKnZ2dnUU7-QvNnZ2d@supernews.com> |
On 10/5/2016 7:48 PM, Elizabeth D. Rather wrote: > On 10/5/16 11:36 AM, rickman wrote: >> On 10/5/2016 4:50 PM, Cecil Bayona wrote: >>> >>> >>> On 10/5/2016 3:07 PM, rickman wrote: >>>> On 10/5/2016 1:18 PM, Cecil Bayona wrote: >>>>> >>>>> >>>>> On 10/5/2016 11:58 AM, Hans Bezemer wrote: >>>>>> rickman wrote: >>>>>>> I think you mean you have two separate stacks sharing one block of >>>>>>> memory, one growing up and the other growing down. That's not >>>>>>> really a >>>>>>> single stack. There are two stack pointers. >>>>>> Absolutely correct. But since there is no way to tell whether a item >>>>>> on a >>>>>> certain location on any particular moment is a data- or a return >>>>>> item, I >>>>>> consider it a shared stack. All a matter of definition, I guess. But >>>>>> you >>>>>> know what I meant and that's the important point ;-) >>>>>> >>>>>> Hans Bezemer >>>>>> >>>>> If one has a 1K deep block of RAM, and the stack pointers are 9 bits, >>>>> one having bit 10 high, the other having bit 10 low. the two stacks >>>>> will >>>>> never run into each other, they will each wrap around their own 512 >>>>> byte >>>>> space. >>>>> >>>>> Another scheme is one stack grows down and starts at the top of RAM, >>>>> the >>>>> other starts at the bottom and grows upwards. all is OK as long as the >>>>> sum of the depth of both stacks is not 1024 or greater. This has more >>>>> flexibility as one stack can be way bigger than the other as >>>>> needed. In >>>>> this case the stack pointers are 10 bits. >>>>> >>>>> In both cases one would buffer the stacks with registers as the TOS, I >>>>> like one for the Program Stack and two levels of buffering for the >>>>> DATA >>>>> stack so that the top 3 Data stack levels are ready to be used with no >>>>> delays. >>>> >>>> Not sure why having the top three items of the stack available is >>>> important. The CPU I designed had a register for the top of stack and >>>> used the block RAM for the next on stack. The block RAM looks like a >>>> register so for all intents and purposes, this functionally was two >>>> registers as the top two items on the stack. This arrangement allows >>>> all the more common Forth words to be implemented in one clock cycle. >>>> The only one I can think of off the top of my head that can't be >>>> supported by this is ROT, which according to Koopman is 13 in dynamic >>>> frequency of use averaging about 2% and not in the list of the top >>>> 18 in >>>> static frequency of use, so not a terrible thing to construct from >>>> primitives. >>>> >>>> Why do you feel it useful to cache three stack items on chip? Unless >>>> the stack was in external RAM and the three cached stack items were >>>> used >>>> as a flexible FIFO to minimize memory accesses, I don't see the >>>> utility. >>>> Is this to accommodate combining instructions for parallel execution? >>>> >>> No Parallel execution yet, but just because. >>> >>> TOS and the RAM itself are enough for many operations, but there are >>> also a bunch that reaches for the third item, with two registers and RAM >>> that makes the top 3 stack items accessible with no speed penalty so >>> makes things a little faster. No much but it doesn't cost much to have >>> TOS and two lower levels available. >> >> I'm trying to understand what "bunch" of operations use three stack >> items. The only common one that comes to mind is ROT. There is not >> much reason to optimize infrequently used operations. > > Source, destination, count? There's a bunch of words (moves, compares) > that take those three. Not a huge bunch, though. > >> If you are designing a MISC, the extra register may be more than you >> think. The register itself is not so much, but the data path connecting >> the registers and functional units blossoms dramatically when adding >> registers. In FPGAs and most ASICs, there are no "busses". Instead >> every data source on a bus is an input to a mux. If controlled >> separately, this mux must be duplicated for every register written to. >> The logic required can be order n^2. >> > > Cheers, > Elizabeth > It will try to combine multiple instructions and generate a better sequence hence sometime having access to the 3rd stack item come handy. In a z80 it would use indexed access but on a stack machine that may not be possible. The Forth CPU I'm thinking of creating would have two index registers to access general memory but not the stacks which is a separate memory space, but I may change my mind on that issue, nothing is final until one is six feet under. The FPGA I will use has 21K 4 input LUTs it should be plenty for what I'm thinking about, a somewhat similar implementation minus the index registers I have been working on uses 28% of a 5K LUT device. -- Cecil - k5nwa
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Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-03 08:22 -0400
Re: Stack Sizes foxaudioresearch@gmail.com - 2016-10-03 07:00 -0700
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-03 11:14 -0400
Re: Stack Sizes Bernd Linsel <bl1@gmx.com> - 2016-10-03 18:20 +0200
Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-03 11:30 -0500
Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-03 15:27 -0400
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-03 18:12 -0400
Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-03 17:52 -0500
Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-03 16:06 -0700
Re: Stack Sizes Jan Coombs <jenfhaomndgfwutc@murmic.plus.com> - 2016-10-04 08:31 +0100
Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-04 08:46 +0000
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-04 10:38 -0400
Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-04 11:59 -0700
Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-05 09:59 +0000
Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-05 10:16 -0400
Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-06 08:21 +0000
Re: Stack Sizes minforth@arcor.de - 2016-10-04 05:00 -0700
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-04 08:49 -0400
Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-03 16:28 -0700
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-04 10:36 -0400
Re: Stack Sizes Rod Pemberton <NoHaveNotOne@zxdehrnyya.cam> - 2016-10-04 16:15 -0400
Re: Stack Sizes Brad Eckert <hwfwguy@gmail.com> - 2016-11-09 09:56 -0800
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-11-12 09:15 -0500
Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-03 10:35 -0500
Re: Stack Sizes Bernd Paysan <bernd@net2o.de> - 2016-10-11 01:01 +0000
Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-03 10:21 -0400
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-03 11:06 -0400
Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-03 15:22 -0400
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-03 18:04 -0400
Re: Stack Sizes Hans Bezemer <the.beez.speaks@gmail.com> - 2016-10-04 20:46 +0200
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-04 15:40 -0400
Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-05 12:26 -0700
Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-05 15:44 -0500
Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-05 16:32 -0700
Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-05 20:01 -0400
Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-07 07:39 +0000
Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-05 20:36 -0500
Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-05 21:28 -0700
Re: Stack Sizes alex <alex@rivadpm.com> - 2016-10-05 22:07 +0100
Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-06 00:05 -0700
Re: Stack Sizes Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-10-06 02:17 -0500
Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-04 19:27 -0400
Re: Stack Sizes Hans Bezemer <the.beez.speaks@gmail.com> - 2016-10-05 18:58 +0200
Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-05 13:17 -0400
Re: Stack Sizes Hans Bezemer <the.beez.speaks@gmail.com> - 2016-10-22 12:35 +0200
Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-05 12:18 -0500
Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-05 16:07 -0400
Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-05 15:50 -0500
Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-05 17:36 -0400
Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-05 17:14 -0500
Re: Stack Sizes "Elizabeth D. Rather" <erather@forth.com> - 2016-10-05 14:48 -1000
Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-05 20:49 -0500
Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-03 16:32 +0000
Re: Stack Sizes Chris Curl <ccurl609@gmail.com> - 2016-10-03 13:53 -0700
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-03 17:54 -0400
Re: Stack Sizes Rod Pemberton <NoHaveNotOne@zxdehrnyya.cam> - 2016-10-03 23:40 -0400
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-04 11:30 -0400
Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-03 21:47 -0700
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-04 11:22 -0400
Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-04 11:44 -0700
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-04 15:53 -0400
Re: Stack Sizes Rod Pemberton <NoHaveNotOne@zxdehrnyya.cam> - 2016-10-04 16:15 -0400
Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-05 14:31 -0700
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-06 08:48 -0400
Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-06 13:08 -0700
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-06 19:11 -0400
Re: Stack Sizes jim.brakefield@ieee.org - 2016-10-06 12:08 -0700
Re: Stack Sizes alex <alex@rivadpm.com> - 2016-10-06 21:47 +0100
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-06 19:05 -0400
Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-06 21:57 -0400
Re: Stack Sizes jim.brakefield@ieee.org - 2016-10-06 19:21 -0700
Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-07 00:10 -0400
Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-06 23:14 -0700
Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-07 02:26 -0400
Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-06 23:57 -0700
Re: Stack Sizes Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-10-07 08:18 -0500
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-07 10:52 -0400
Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-09 16:22 -0700
Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-10 01:49 -0400
Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-10 10:21 -0500
Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-10 22:39 -0400
Straight Forth Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-10 12:36 +0200
Re: Straight Forth Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-13 13:45 -0700
Re: Straight Forth Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-14 01:16 -0700
Re: Straight Forth Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-15 20:38 -0700
Re: Straight Forth Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-16 02:00 -0400
Re: Straight Forth Re: Stack Sizes lawrencedo99@gmail.com - 2016-10-16 18:38 -0700
Re: Straight Forth Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-16 22:27 -0400
Re: Straight Forth Re: Stack Sizes Raimond Dragomir <raimond.dragomir@gmail.com> - 2016-10-16 21:14 -0700
Re: Straight Forth Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-17 00:35 -0400
Re: Straight Forth Re: Stack Sizes Raimond Dragomir <raimond.dragomir@gmail.com> - 2016-10-16 23:31 -0700
Re: Straight Forth Re: Stack Sizes "Elizabeth D. Rather" <erather@forth.com> - 2016-10-16 20:36 -1000
Re: Straight Forth Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-17 13:11 -0700
Re: Straight Forth Re: Stack Sizes Rod Pemberton <NeedNotReplyHere@xrsevnneqk.cem> - 2016-10-17 19:14 -0400
Re: Straight Forth Re: Stack Sizes Bernd Paysan <bernd@net2o.de> - 2016-10-17 21:53 +0000
Re: Straight Forth Re: Stack Sizes lawrencedo99@gmail.com - 2016-10-17 16:54 -0700
Re: Straight Forth Re: Stack Sizes Bernd Paysan <bernd@net2o.de> - 2016-10-21 22:13 +0000
Re: Straight Forth Re: Stack Sizes lawrencedo99@gmail.com - 2016-10-21 17:46 -0700
Re: Straight Forth Re: Stack Sizes Bernd Paysan <bernd@net2o.de> - 2016-10-23 22:26 +0000
Re: Straight Forth Re: Stack Sizes JUERGEN <epldfpga@aol.com> - 2016-10-24 09:13 -0700
Re: Straight Forth Re: Stack Sizes lawrencedo99@gmail.com - 2016-10-24 16:28 -0700
Re: Straight Forth Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-24 17:20 -0700
Re: Straight Forth Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-24 22:23 -0400
Re: Straight Forth Re: Stack Sizes Bernd Paysan <bernd@net2o.de> - 2016-11-04 20:39 +0000
Re: Straight Forth Re: Stack Sizes lawrencedo99@gmail.com - 2016-10-16 22:42 -0700
Re: Straight Forth Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-17 11:12 +0200
Re: Straight Forth Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-17 09:20 -0700
Re: Straight Forth Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-17 19:11 -0400
Re: Straight Forth Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-17 16:40 -0700
Re: Straight Forth Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-17 20:19 -0400
Re: Straight Forth Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-17 17:25 -0700
Re: Straight Forth Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-17 20:50 -0400
Re: Straight Forth Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-18 02:04 +0200
Re: Straight Forth Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-18 06:13 +0000
Re: Straight Forth Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-16 15:21 -0700
Re: Straight Forth Re: Stack Sizes Doug Hoffman <glidedog@gmail.com> - 2016-10-17 04:09 -0400
Re: Straight Forth Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-17 13:48 -0700
Re: Straight Forth Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-18 02:12 +0200
Re: Straight Forth Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-18 00:35 -0700
Re: Straight Forth Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-18 12:53 +0200
Re: Straight Forth Re: Stack Sizes hughaguilar96@gmail.com - 2016-10-18 12:12 -0700
Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-07 16:53 +0000
Re: Stack Sizes Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-10-09 08:34 -0500
Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-09 16:03 +0000
Re: Stack Sizes Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-10-10 03:25 -0500
Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-10 10:29 -0500
Re: Stack Sizes Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-10-11 05:19 -0500
Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-10 14:41 +0000
Re: Stack Sizes Lars Brinkhoff <lars.spam@nocrew.org> - 2016-10-10 20:23 +0200
Re: Stack Sizes Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-10-11 05:16 -0500
Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-12 12:54 +0000
Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-12 18:27 +0200
Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-12 17:06 +0000
Re: Stack Sizes Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-10-12 13:01 -0500
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-12 17:07 -0400
Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-13 03:18 +0200
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-14 14:26 -0400
Re: Stack Sizes lawrencedo99@gmail.com - 2016-10-12 20:30 -0700
Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-13 15:52 +0000
Re: Stack Sizes lawrencedo99@gmail.com - 2016-10-13 15:05 -0700
Re: Stack Sizes Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-10-14 03:08 -0500
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-14 14:41 -0400
Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-07 12:33 -0500
Re: Stack Sizes rickman <gnuarm@gmail.com> - 2016-10-08 01:12 -0400
Re: Stack Sizes Rod Pemberton <NeedNotReplyHere@xrsevnneqk.cem> - 2016-10-07 23:05 -0400
Re: Stack Sizes jim.brakefield@ieee.org - 2016-10-07 21:56 -0700
Re: Stack Sizes Walter Banks <walter@bytecraft.com> - 2016-10-08 07:23 -0400
Re: Stack Sizes lawrencedo99@gmail.com - 2016-10-11 22:39 -0700
Re: Stack Sizes Lars Brinkhoff <lars.spam@nocrew.org> - 2016-10-07 08:21 +0200
Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-07 09:22 +0200
Re: Stack Sizes Lars Brinkhoff <lars.spam@nocrew.org> - 2016-10-07 09:35 +0200
Re: Stack Sizes jim.brakefield@ieee.org - 2016-10-07 10:51 -0700
Re: Stack Sizes Cecil Bayona <cbayona@cbayona.com> - 2016-10-07 13:21 -0500
Re: Stack Sizes Lars Brinkhoff <lars.spam@nocrew.org> - 2016-10-07 20:40 +0200
Re: Stack Sizes albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-10-07 20:53 +0200
Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-07 07:35 +0000
Re: Stack Sizes Paul Rubin <no.email@nospam.invalid> - 2016-10-07 01:09 -0700
Re: Stack Sizes anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-10-07 15:59 +0000
Re: Stack Sizes Bernd Paysan <bernd@net2o.de> - 2016-10-17 22:05 +0000
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