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Groups > comp.sys.raspberry-pi > #12724 > unrolled thread
| Started by | "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> |
|---|---|
| First post | 2016-07-18 10:50 +0100 |
| Last post | 2016-07-20 10:53 -0400 |
| Articles | 10 on this page of 50 — 20 participants |
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Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-18 10:50 +0100
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-19 20:25 -0400
Re: Jazelle? The Natural Philosopher <tnp@invalid.invalid> - 2016-07-20 07:08 +0100
Re: Jazelle? Paul <paul@pcserviceselectronics.co.uk> - 2016-07-20 08:54 +0100
Re: Jazelle? The Natural Philosopher <tnp@invalid.invalid> - 2016-07-20 09:29 +0100
Re: Jazelle? Gordon Henderson <gordon+usenet@drogon.net> - 2016-07-20 12:56 +0000
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-20 14:54 +0100
Re: Jazelle? Folderol <general@musically.me.uk> - 2016-07-20 18:40 +0100
Re: Jazelle? The Natural Philosopher <tnp@invalid.invalid> - 2016-07-20 19:12 +0100
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 15:17 -0400
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-20 20:32 +0100
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 15:37 -0400
CAN / LIN auto bus (was Jazelle?) jeffj@panix.com (Jeff Jonas) - 2016-07-20 17:53 -0400
Re: CAN / LIN auto bus (was Jazelle?) Martin Gregorie <martin@address-in-sig.invalid> - 2016-07-20 22:28 +0000
Re: CAN / LIN auto bus (was Jazelle?) druck <news@druck.org.uk> - 2016-07-20 23:37 +0100
Re: Jazelle? alister <alister.ware@ntlworld.com> - 2016-07-20 13:34 +0000
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 10:26 -0400
Re: Jazelle? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2016-07-20 19:51 -0400
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-20 10:31 +0100
Re: Jazelle? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-07-20 10:14 +0000
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-20 14:49 +0100
Re: Jazelle? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-07-20 14:35 +0000
Re: Jazelle? mm0fmf <none@invalid.com> - 2016-07-20 17:39 +0100
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-20 20:30 +0100
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 15:35 -0400
Re: Jazelle? "WJ" <w_a_x_man@yahoo.com> - 2016-07-21 10:43 +0000
Re: Jazelle? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-07-21 12:44 +0000
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-21 22:59 +0100
Re: Jazelle? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-07-22 06:42 +0000
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-22 12:03 +0100
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-22 09:05 -0400
Re: Jazelle? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2016-07-22 19:20 +0300
Re: Jazelle? "WJ" <w_a_x_man@yahoo.com> - 2016-07-25 10:43 +0000
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-26 11:41 +0100
Re: Jazelle? Doug Hoffman <glidedog@gmail.com> - 2016-07-20 06:44 -0400
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-20 14:52 +0100
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 10:52 -0400
Re: Jazelle? alister <alister.ware@ntlworld.com> - 2016-07-20 15:40 +0000
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 11:46 -0400
Re: Jazelle? Robert Riches <spamtrap42@jacob21819.net> - 2016-07-21 01:27 +0000
Re: Jazelle? "A. Dumas" <alexandre@dumas.fr.invalid> - 2016-07-21 05:58 +0200
Re: Jazelle? colonel_hack@yahoo.com - 2016-07-21 16:29 -0700
Re: Jazelle? "A. Dumas" <alexandre@dumas.fr.invalid> - 2016-07-22 01:56 +0200
Re: Jazelle? colonel_hack@yahoo.com - 2016-07-22 14:04 -0700
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-22 11:59 +0100
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 10:56 -0400
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 10:24 -0400
Re: Jazelle? Theo Markettos <theom+news@chiark.greenend.org.uk> - 2016-07-20 14:38 +0100
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-20 14:57 +0100
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 10:53 -0400
Page 3 of 3 — ← Prev page 1 2 [3]
| From | "A. Dumas" <alexandre@dumas.fr.invalid> |
|---|---|
| Date | 2016-07-21 05:58 +0200 |
| Message-ID | <57904870$0$5842$e4fe514c@news.xs4all.nl> |
| In reply to | #12775 |
On 21/07/2016 03:27, Robert Riches wrote:
> On 2016-07-20, Doug Hoffman wrote:
>> The reality is that neither algebraic or RPN matches the way we would
>> express the equation in class using pencil and paper.
>> (view the following in a monospaced font)
>> ______________
>> x = -b +- / b2 - 4ac
>> \/ -----------
>> 2a
>
> First, a correction to the form of the above expression.
> According to this page,
>
> https://en.wikipedia.org/wiki/Quadratic_formula
>
> the -b is also over the 2a. It would be more accurately written
> with paper and pencil as this:
>
> ______________
> x = -b +- / b2 - 4ac
> \/
> -------------------------
> 2a
>
> (end of expression form correction)
>
> The assertion that algebraic does not match the way we would
> express the formula using paper and pencil is not quite true--at
> least for one definition of algebraic entry.
As this comp.sys.raspberry-pi,
pi@raspberrypi:~ $ wolfram
Wolfram Language (Raspberry Pi Pilot Release)
Copyright 1988-2016 Wolfram Research
Information & help: wolfram.com/raspi
In[1]:= Solve[a x^2 + b x + c == 0, x]
2 2
-b - Sqrt[b - 4 a c] -b + Sqrt[b - 4 a c]
Out[1]= {{x -> ---------------------}, {x -> ---------------------}}
2 a 2 a
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| From | colonel_hack@yahoo.com |
|---|---|
| Date | 2016-07-21 16:29 -0700 |
| Message-ID | <alpine.LFD.2.20.1607211412260.28509@localhost> |
| In reply to | #12776 |
On Thu, 21 Jul 2016, A. Dumas wrote:
>
> As this comp.sys.raspberry-pi,
>
> pi@raspberrypi:~ $ wolfram
> Wolfram Language (Raspberry Pi Pilot Release)
> Copyright 1988-2016 Wolfram Research
> Information & help: wolfram.com/raspi
>
> In[1]:= Solve[a x^2 + b x + c == 0, x]
> 2 2
> -b - Sqrt[b - 4 a c] -b + Sqrt[b - 4 a c]
> Out[1]= {{x -> ---------------------}, {x -> ---------------------}}
> 2 a 2 a
>
>
Or
pi@raspberrypi:~ $ maxima
Maxima 5.34.1 http://maxima.sourceforge.net
using Lisp GNU Common Lisp (GCL) GCL 2.6.12 (a.k.a. GCL)
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) 7*x^2+5*x-4;
2
(%o1) 7 x + 5 x - 4
(%i2) solve(%);
sqrt(137) + 5 sqrt(137) - 5
(%o2) [x = - -------------, x = -------------]
14 14
You'll probably have to install maxima. As a plus for me, w/maxima I have
the same thing on my pi, my desktop and my phone.
Matematicsa's notation feels awkward to me, but it's been a while. Is the
capital S really required for Solve? Not solve?
And for a bit of math (Hey, the pi is nominally an educational system),
writing it as
-b sqrt(b^2-4ac)
--- +/- -------------
2a 2a
You have
-b/2a is the axis of symmetry & sqrt(b^2-4ac)/2a is the distance to the
roots.
Ron
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| From | "A. Dumas" <alexandre@dumas.fr.invalid> |
|---|---|
| Date | 2016-07-22 01:56 +0200 |
| Message-ID | <5791613a$0$5812$e4fe514c@news.xs4all.nl> |
| In reply to | #12780 |
On 22/07/2016 01:29, colonel_hack@yahoo.com wrote:
> pi@raspberrypi:~ $ maxima
>
> Maxima 5.34.1 http://maxima.sourceforge.net
> using Lisp GNU Common Lisp (GCL) GCL 2.6.12 (a.k.a. GCL)
> Distributed under the GNU Public License. See the file COPYING.
> Dedicated to the memory of William Schelter.
> The function bug_report() provides bug reporting information.
> (%i1) 7*x^2+5*x-4;
> 2
> (%o1) 7 x + 5 x - 4
> (%i2) solve(%);
> sqrt(137) + 5 sqrt(137) - 5
> (%o2) [x = - -------------, x = -------------]
> 14 14
>
> You'll probably have to install maxima.
I would, when Mathematica comes pre-installed.
> As a plus for me, w/maxima I
> have the same thing on my pi, my desktop and my phone.
That's undoubtedly an advantage.
> Matematicsa's notation feels awkward to me, but it's been a while. Is
> the capital S really required for Solve? Not solve?
Yes, all built-in and library functions are word-capitalised
("PascalCase"). I'm OK with that. However, I still don't like the square
brackets. What seemed awkward to me in your example is the implied
equation to zero (might be handy actually) and no indication of which
variable to solve for (but obvious in this case with only x).
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| From | colonel_hack@yahoo.com |
|---|---|
| Date | 2016-07-22 14:04 -0700 |
| Message-ID | <alpine.LFD.2.20.1607212319410.30930@localhost> |
| In reply to | #12781 |
On Fri, 22 Jul 2016, A. Dumas wrote:
> Yes, all built-in and library functions are word-capitalised ("PascalCase").
> I'm OK with that.
Yeah, it really wouldn't be hard to get used to.
> However, I still don't like the square brackets.
That seems like it was the main thing I didn't like about the syntax. I
was used to reduce's syntax at the time but that's back a bit. I might not
like it either now (Oh, hey, there's a raspberry pi version of reduce.
There, that keeps this on topic :-)
> What seemed awkward to me in your example is the implied equation to
> zero (might be handy actually) and no indication of which variable to
> solve for (but obvious in this case with only x).
I'm enough used to the implied zero that it seems natural, I think maple
and reduce might allow it also. derive assumes =0 but if you have more
than one variable it asks ``solve variable: x'' where the x can be changed.
In maxima:
(%i1) x^2+x*y+y^2;
2 2
(%o1) y + x y + x
(%i2) solve(%);
solve: more unknowns than equations.
Unknowns given :
[y, x]
Equations given:
2 2
[y + x y + x ]
-- an error. To debug this try: debugmode(true);
(%i3) solve(%o1,x);
(sqrt(3) %i + 1) y (sqrt(3) %i - 1) y
(%o3) [x = - ------------------, x = ------------------]
2 2
(%i4) solve(%o1=12,x);
2 2
sqrt(3) sqrt(16 - y ) + y sqrt(3) sqrt(16 - y ) - y
(%o4) [x = - -------------------------, x = -------------------------]
2 2
The maxima error message does seem a bit big iron, not like a modern
release product.
My main concern, with the implied =0, would be if you were using it
educationally is that it blurs the distiction between an expression and an
equation, something that gives some people trouble in algebra 101.
Ron
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| From | "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> |
|---|---|
| Date | 2016-07-22 11:59 +0100 |
| Message-ID | <nmsuat$l0e$1@dont-email.me> |
| In reply to | #12780 |
<colonel_hack@yahoo.com> wrote in message news:alpine.LFD.2.20.1607211412260.28509@localhost... > -b/2a is the axis of symmetry & sqrt(b^2-4ac)/2a is the distance to the > roots. That's a very interesting way of interpreting it. Thanks
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2016-07-20 10:56 -0400 |
| Message-ID | <nmo3fd$q3d$2@dont-email.me> |
| In reply to | #12740 |
On 7/20/2016 5:31 AM, gareth G4SDW GQRP #3339 wrote: > "Paul" <paul@pcserviceselectronics.co.uk> wrote in message > news:MPG.31f93e8b429c8383989804@172.16.0.1... >> In article <nmn4gf$p1o$2@news.albasani.net>, tnp@invalid.invalid says... >>> On 20/07/16 01:25, rickman wrote: >>>> On 7/18/2016 5:50 AM, gareth G4SDW GQRP #3339 wrote: >>>>> I wonder if anyone has done any experiments to determine what the >>>>> Jazelle byte codes are, for use of such things should produce code >>>>> that is even more compact than Thumb? >>>>> >>>>> e.g single steppint code and then examining the changes that have >>>>> been wrought by each code, allowing for some extra bytes as >>>>> addresses or immediate data. >>>> >>>> If you want high code density, you should learn Forth. It can support >>>> a >>>> complete Forth compiler in as little as 16 kB. >>>> >>> Indeed. More compact than assembler really! > > But Forth _IS_ assembler, for it is based on the prior published > art of the KDF9 computer architecture along with its drop, dup, data and > return stacks. Why do you say Forth is based on any particular computer design? Forth emulates an abstract stack based CPU. The KDF9 is one of many which had been designed by the time Forth was invented. -- Rick C
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2016-07-20 10:24 -0400 |
| Message-ID | <nmo1iv$k2b$1@dont-email.me> |
| In reply to | #12733 |
On 7/20/2016 2:08 AM, The Natural Philosopher wrote: > On 20/07/16 01:25, rickman wrote: >> On 7/18/2016 5:50 AM, gareth G4SDW GQRP #3339 wrote: >>> I wonder if anyone has done any experiments to determine what the >>> Jazelle byte codes are, for use of such things should produce code >>> that is even more compact than Thumb? >>> >>> e.g single steppint code and then examining the changes that have >>> been wrought by each code, allowing for some extra bytes as >>> addresses or immediate data. >> >> If you want high code density, you should learn Forth. It can support a >> complete Forth compiler in as little as 16 kB. >> > Indeed. More compact than assembler really! Yeah, actually. It has a bit of overhead, but the language promotes code reuse and a high degree of factoring which results in tighter code than other languages (including assembler). Of course you can duplicate the same features by emulating Forth in other languages, but the languages themselves do not promote that. > But in these days of GB RAM who cares? Obviously the OP cares or he wouldn't have asked. -- Rick C
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| From | Theo Markettos <theom+news@chiark.greenend.org.uk> |
|---|---|
| Date | 2016-07-20 14:38 +0100 |
| Message-ID | <fPf*6+94v@news.chiark.greenend.org.uk> |
| In reply to | #12730 |
> On 7/18/2016 5:50 AM, gareth G4SDW GQRP #3339 wrote: > > I wonder if anyone has done any experiments to determine what the > > Jazelle byte codes are, for use of such things should produce code > > that is even more compact than Thumb? Jazelle isn't supported on modern ARMs. "The Cortex-A7 MPCore processor provides a trivial implementation of the Jazelle Extension. This means that the processor does not accelerate the execution of any bytecodes. In the trivial implementation of the Jazelle Extension: Jazelle state is not supported the BXJ instruction behaves as a BX instruction." http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0464d/CHDIEFFJ.html ditto A53. ARM1176JZF-S does support it, but it's a dead end. Theo
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| From | "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> |
|---|---|
| Date | 2016-07-20 14:57 +0100 |
| Message-ID | <nmnvvq$fl5$1@dont-email.me> |
| In reply to | #12746 |
"Theo Markettos" <theom+news@chiark.greenend.org.uk> wrote in message news:fPf*6+94v@news.chiark.greenend.org.uk... >> On 7/18/2016 5:50 AM, gareth G4SDW GQRP #3339 wrote: >> > I wonder if anyone has done any experiments to determine what the >> > Jazelle byte codes are, for use of such things should produce code >> > that is even more compact than Thumb? > Jazelle isn't supported on modern ARMs. > "The Cortex-A7 MPCore processor provides a trivial implementation of the > Jazelle Extension. This means that the processor does not accelerate the > execution of any bytecodes. > In the trivial implementation of the Jazelle Extension: > Jazelle state is not supported > the BXJ instruction behaves as a BX instruction." > http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0464d/CHDIEFFJ.html > > ditto A53. ARM1176JZF-S does support it, but it's a dead end. OK, thanks. The concept of byte code expansion into instruction streams in hardware was intriguing.
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2016-07-20 10:53 -0400 |
| Message-ID | <nmo39s$q3d$1@dont-email.me> |
| In reply to | #12750 |
On 7/20/2016 9:57 AM, gareth G4SDW GQRP #3339 wrote: > "Theo Markettos" <theom+news@chiark.greenend.org.uk> wrote in message > news:fPf*6+94v@news.chiark.greenend.org.uk... >>> On 7/18/2016 5:50 AM, gareth G4SDW GQRP #3339 wrote: >>>> I wonder if anyone has done any experiments to determine what the >>>> Jazelle byte codes are, for use of such things should produce code >>>> that is even more compact than Thumb? >> Jazelle isn't supported on modern ARMs. >> "The Cortex-A7 MPCore processor provides a trivial implementation of the >> Jazelle Extension. This means that the processor does not accelerate the >> execution of any bytecodes. >> In the trivial implementation of the Jazelle Extension: >> Jazelle state is not supported >> the BXJ instruction behaves as a BX instruction." >> http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0464d/CHDIEFFJ.html >> >> ditto A53. ARM1176JZF-S does support it, but it's a dead end. > > OK, thanks. The concept of byte code expansion into instruction streams in > hardware > was intriguing. Yes, Forth is often written that way. Very intriguing. -- Rick C
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