Re: Expected BASE-LINE for Embedded Controllers

From	Bernd Paysan <bernd.paysan@gmx.de>
Newsgroups	comp.lang.forth
Subject	Re: Expected BASE-LINE for Embedded Controllers
Date	2015-01-21 00:40 +0100
Organization	A noiseless patient Spider
Message-ID	<m9mp01$5us$1@dont-email.me> (permalink)
References	(1 earlier) <m9h8f4$js8$1@dont-email.me> <m9ioho$nl1$1@newsserver.rrzn.uni-hannover.de> <873875b7fd.fsf@jester.gateway.sonic.net> <m9mksr$n78$1@dont-email.me> <87twzl9isf.fsf@jester.gateway.sonic.net>

Show all headers | View raw

Paul Rubin wrote:

> Bernd Paysan <bernd.paysan@gmx.de> writes:
>> SP@/RP@/SP!/RP! are these tools, defining a complete multitasking wordset
>> that works well from medium to large systems is overkill for the tiny
>> systems.
> 
> Another example where SP@ etc can get in the way, is if you have a
> VFX-like host-side compiler that places a lot of the target's stack
> items in registers.

No.  SP@ is just a normalization point.  SP@ works fine in VFX.

: test 1 2 3 + + . ;  ok
see test  
TEST 
( 080BF310    8D6DFC )                LEA       EBP, [EBP+-04]
( 080BF313    895D00 )                MOV       [EBP], EBX
( 080BF316    BB06000000 )            MOV       EBX, 00000006
( 080BF31B    E8803DF9FF )            CALL      080530A0        .
( 080BF320    C3 )                    NEXT,
( 17 bytes, 5 instructions )
 ok

Now we add an SP@ in between:

: test 1 2 3 sp@ >r + + . r> ;  
TEST is redefined  ok
see test  
TEST 
( 080BF340    8D6DF4 )                LEA       EBP, [EBP+-0C]
( 080BF343    C7450002000000 )        MOV       DWord Ptr [EBP], 00000002
( 080BF34A    C7450401000000 )        MOV       DWord Ptr [EBP+04], 00000001
( 080BF351    895D08 )                MOV       [EBP+08], EBX
( 080BF354    BB03000000 )            MOV       EBX, 00000003
( 080BF359    E82EFCF8FF )            CALL      0804EF8C        SP@
( 080BF35E    53 )                    PUSH      EBX
( 080BF35F    8B5D00 )                MOV       EBX, [EBP]
( 080BF362    035D04 )                ADD       EBX, [EBP+04]
( 080BF365    035D08 )                ADD       EBX, [EBP+08]
( 080BF368    8D6D0C )                LEA       EBP, [EBP+0C]
( 080BF36B    E8303DF9FF )            CALL      080530A0        .
( 080BF370    5A )                    POP       EDX
( 080BF371    8D6DFC )                LEA       EBP, [EBP+-04]
( 080BF374    895D00 )                MOV       [EBP], EBX
( 080BF377    8BDA )                  MOV       EBX, EDX
( 080BF379    C3 )                    NEXT,
( 58 bytes, 17 instructions )

Oh, all registers are saved, perfect.  The implementation is completely 
straight-forward: SP@ is marked as word that can't be inlined, and all those 
words are normalization points anyway.  The big difference between a Forth 
compiler and the textbook compilers is that you have this normalization 
points.

> So the task switcher would save the registers like
> in a conventional OS, and exposing SP@ etc. to the target would make
> things messy.  It seems ok to let the switcher use carnal knowledge.

No, we know how to implement SP@, we don't need someone telling us that it 
can't be done.  The problem is solved.

> When I mentioned an FPGA processor I wasn't thinking of the tiny
> b16-like category, but maybe something more like the J1.

The J1 is about as tiny as the b16 (the Verilog is even smaller, because the 
J1 has a less dense instruction encoding), has the same model of separate 
very small memory blocks for the data and return stack, and those pointers 
can't be set by the program (though there's a way to obtain its value, which 
is missing in the b16 - you can do DEPTH on J1, but not on b16; you can't do 
SP! on either).

> I like the idea of standardized multitasking words, so that programs
> that use them can be portable (or at least more portable than they are
> now).

We like that, too, but it is not the right thing for a base-line wordset for 
embedded controllers, which is the topic *here*.

-- 
Bernd Paysan
"If you want it done right, you have to do it yourself"
http://bernd-paysan.de/
net2o ID: kQusJzA;7*?t=uy@X}1GWr!+0qqp_Cn176t4(dQ*

Thread

Expected BASE-LINE for Embedded Controllers Paul E Bennett <Paul_E.Bennett@topmail.co.uk> - 2015-01-18 11:58 +0000
  Re: Expected BASE-LINE for Embedded Controllers Matthias Trute <matthias.trute@gmail.com> - 2015-01-18 04:55 -0800
    Re: Expected BASE-LINE for Embedded Controllers Mikael Nordman <oh2aun@gmail.com> - 2015-01-18 10:20 -0800
    Re: Expected BASE-LINE for Embedded Controllers visualforth@rocketmail.com - 2015-01-20 10:45 -0800
      Re: Expected BASE-LINE for Embedded Controllers "Elizabeth D. Rather" <erather@forth.com> - 2015-01-20 12:34 -1000
        Re: Expected BASE-LINE for Embedded Controllers visualforth@rocketmail.com - 2015-01-20 16:40 -0800
  Re: Expected BASE-LINE for Embedded Controllers Bernd Paysan <bernd.paysan@gmx.de> - 2015-01-18 22:27 +0100
    Re: Expected BASE-LINE for Embedded Controllers "Elizabeth D. Rather" <erather@forth.com> - 2015-01-18 13:45 -1000
      Re: Expected BASE-LINE for Embedded Controllers albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-01-19 18:22 +0000
    Re: Expected BASE-LINE for Embedded Controllers Matthias Koch <matthias.koch@hot.uni-hannover.de> - 2015-01-19 12:06 +0100
      Re: Expected BASE-LINE for Embedded Controllers albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-01-19 18:47 +0000
        Re: Expected BASE-LINE for Embedded Controllers "Elizabeth D. Rather" <erather@forth.com> - 2015-01-19 11:22 -1000
          Re: Expected BASE-LINE for Embedded Controllers albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-01-20 11:54 +0000
        Re: Expected BASE-LINE for Embedded Controllers Matthias Koch <matthias.koch@hot.uni-hannover.de> - 2015-01-20 09:49 +0100
      Re: Expected BASE-LINE for Embedded Controllers Bernd Paysan <bernd.paysan@gmx.de> - 2015-01-19 20:27 +0100
      Re: Expected BASE-LINE for Embedded Controllers Paul Rubin <no.email@nospam.invalid> - 2015-01-20 11:04 -0800
        Re: Expected BASE-LINE for Embedded Controllers Mark Wills <markwills1970@gmail.com> - 2015-01-20 11:33 -0800
        Re: Expected BASE-LINE for Embedded Controllers Bernd Paysan <bernd.paysan@gmx.de> - 2015-01-20 23:30 +0100
          Re: Expected BASE-LINE for Embedded Controllers Paul Rubin <no.email@nospam.invalid> - 2015-01-20 14:41 -0800
            Re: Expected BASE-LINE for Embedded Controllers Bernd Paysan <bernd.paysan@gmx.de> - 2015-01-21 00:40 +0100
              Re: Expected BASE-LINE for Embedded Controllers Paul Rubin <no.email@nospam.invalid> - 2015-01-20 15:53 -0800
                Re: Expected BASE-LINE for Embedded Controllers Bernd Paysan <bernd.paysan@gmx.de> - 2015-01-21 01:41 +0100
                Re: Expected BASE-LINE for Embedded Controllers "Elizabeth D. Rather" <erather@forth.com> - 2015-01-20 15:38 -1000
                Re: Expected BASE-LINE for Embedded Controllers Paul Rubin <no.email@nospam.invalid> - 2015-01-22 11:08 -0800
                Re: Expected BASE-LINE for Embedded Controllers albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-01-23 16:10 +0000
            Re: Expected BASE-LINE for Embedded Controllers "Elizabeth D. Rather" <erather@forth.com> - 2015-01-20 15:25 -1000
          Re: Expected BASE-LINE for Embedded Controllers albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-01-21 10:40 +0000
  Re: Expected BASE-LINE for Embedded Controllers Matthias Koch <matthias.koch@hot.uni-hannover.de> - 2015-01-19 12:00 +0100
  Re: Expected BASE-LINE for Embedded Controllers Mikael Nordman <oh2aun@gmail.com> - 2015-01-21 00:04 -0800
    Re: Expected BASE-LINE for Embedded Controllers Matthias Koch <matthias.koch@hot.uni-hannover.de> - 2015-01-21 11:53 +0100
    Re: Expected BASE-LINE for Embedded Controllers Mark Wills <markwills1970@gmail.com> - 2015-01-21 03:02 -0800
    Re: Expected BASE-LINE for Embedded Controllers Mark Wills <markwills1970@gmail.com> - 2015-01-21 03:07 -0800
      Re: Expected BASE-LINE for Embedded Controllers Bernd Paysan <bernd.paysan@gmx.de> - 2015-01-22 15:50 +0100
        Re: Expected BASE-LINE for Embedded Controllers anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-01-22 16:39 +0000
        Re: Expected BASE-LINE for Embedded Controllers Paul Rubin <no.email@nospam.invalid> - 2015-01-22 11:13 -0800
          Re: Expected BASE-LINE for Embedded Controllers stephen@mpeforth.com (Stephen Pelc) - 2015-01-23 11:19 +0000
            Re: Expected BASE-LINE for Embedded Controllers albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-01-23 16:12 +0000
          Re: Expected BASE-LINE for Embedded Controllers anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-01-23 16:42 +0000
            Re: Expected BASE-LINE for Embedded Controllers Paul Rubin <no.email@nospam.invalid> - 2015-01-24 01:53 -0800
              Re: Expected BASE-LINE for Embedded Controllers Bernd Paysan <bernd.paysan@gmx.de> - 2015-01-24 15:33 +0100
              Re: Expected BASE-LINE for Embedded Controllers anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-01-25 15:48 +0000

csiph-web