Re: How do you remember the stack?

From	anton@mips.complang.tuwien.ac.at (Anton Ertl)
Newsgroups	comp.lang.forth
Subject	Re: How do you remember the stack?
Date	2016-02-16 14:57 +0000
Organization	Institut fuer Computersprachen, Technische Universitaet Wien
Message-ID	<2016Feb16.155705@mips.complang.tuwien.ac.at> (permalink)
References	(2 earlier) <ac22d4d5-6d55-462e-b829-0fc91920c0c8@googlegroups.com> <2016Feb15.105330@mips.complang.tuwien.ac.at> <56c1b601$0$23760$e4fe514c@news.xs4all.nl> <8906a89c-0486-4f44-af99-589848940a6b@googlegroups.com> <1286489993.477247715.408086.dunno-dunno.dunno@news.mixmin.net>

Show all headers | View raw

dunno <dunno@dunno.dunno> writes:
>I would like to add that there are very legitimate reasons to keep numbers
>on two different stacks. Some processors (namely, x86 and x86-64) actually
>do have two different stacks, including FP stack, and authors of Forth
>implementations are able to use it directly instead of keeping floats in
>memory and moving them to FP stack when needed.

Actually with typical Forth idiomatics and a sufficiently
sophisticated compiler, it is possible to combine various Forth stacks
into one in the implementation, or also split a combined stack into
several for a good part of the code.

But even in such an environment the FP stack is a good idea, for a
similar reason that we have separate FP registers in hardware: there
are relatively few integer operations that make sense on FP values and
vice versa.  In hardware the separate FP registers allow keeping the
integer data close to the integer units and the FP data close to the
FP units, and they also mean that the port requirements of integer and
FP units do not add up in the register files.  In Forth the separate
stacks allow us to avoid stack shuffling when dealing with FP values
(in addition to making it easier for not-sufficiently-sophisticated
compilers to make good use of FP registers or the 80387 FP stack).

There have also been ideas like a separate stack for addresses, but
the overlap of instructions between integers and addresses is so large
that this does not make that much sense; likewise, instruction sets
with general-purpose registers won out over instruction sets like the
68000 with separate address and data registers.

However, as a counterexample to my argument, the Intel SIMD registers
(XMM, YMM etc.)  may contain vectors of integers as well as vectors of
FP values, and there are instructions for dealing with both kinds of
data.

- 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 2015: http://www.rigwit.co.uk/EuroForth2015/

Thread

How do you remember the stack? laheadle@gmail.com - 2016-02-12 13:57 -0800
  Re: How do you remember the stack? Paul Rubin <no.email@nospam.invalid> - 2016-02-12 14:08 -0800
    Re: How do you remember the stack? "HAA" <someone@microsoft.com> - 2016-02-16 13:35 +1100
      Re: How do you remember the stack? Julian Fondren <julian.fondren@gmail.com> - 2016-02-15 19:28 -0800
      Re: How do you remember the stack? Whammo <sidciavic@gmail.com> - 2016-02-15 19:54 -0800
      Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-16 07:28 +0000
        Re: How do you remember the stack? "Elizabeth D. Rather" <erather@forth.com> - 2016-02-15 22:03 -1000
          Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-16 13:30 +0000
            Re: How do you remember the stack? "Elizabeth D. Rather" <erather@forth.com> - 2016-02-16 08:20 -1000
              Re: How do you remember the stack? dunno <dunno@dunno.dunno> - 2016-02-16 20:48 +0000
              Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-17 15:42 +0000
          Re: How do you remember the stack? "HAA" <someone@microsoft.com> - 2016-02-18 18:48 +1100
            Re: How do you remember the stack? hughaguilar96@gmail.com - 2016-02-18 12:27 -0800
              Re: How do you remember the stack? Julian Fondren <julian.fondren@gmail.com> - 2016-02-18 14:53 -0800
                Re: How do you remember the stack? Julian Fondren <julian.fondren@gmail.com> - 2016-02-18 15:18 -0800
              Re: How do you remember the stack? "HAA" <someone@microsoft.com> - 2016-02-21 13:32 +1100
                Re: How do you remember the stack? Chris Curl <ccurl609@gmail.com> - 2016-02-20 20:57 -0800
                Re: How do you remember the stack? Ron Aaron <rambamist@gmail.com> - 2016-02-21 07:23 +0200
                Re: How do you remember the stack? Chris Curl <ccurl609@gmail.com> - 2016-02-21 08:54 -0800
                Re: How do you remember the stack? hughaguilar96@gmail.com - 2016-02-21 22:05 -0800
                Re: How do you remember the stack? Lars Brinkhoff <lars.spam@nocrew.org> - 2016-02-22 16:20 +0100
                Re: How do you remember the stack? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-02-22 09:47 -0600
                Re: How do you remember the stack? Whammo <sidciavic@gmail.com> - 2016-02-23 16:51 -0800
                Re: How do you remember the stack? "HAA" <someone@microsoft.com> - 2016-02-28 15:22 +1100
                Re: How do you remember the stack? hughaguilar96@gmail.com - 2016-02-27 21:30 -0800
                Re: How do you remember the stack? hughaguilar96@gmail.com - 2016-02-27 21:33 -0800
                Re: How do you remember the stack? "Elizabeth D. Rather" <erather@forth.com> - 2016-02-27 21:39 -1000
                Re: How do you remember the stack? "HAA" <someone@microsoft.com> - 2016-02-29 13:47 +1100
                Re: How do you remember the stack? Paul Rubin <no.email@nospam.invalid> - 2016-02-28 19:02 -0800
                Re: How do you remember the stack? Julian Fondren <julian.fondren@gmail.com> - 2016-02-28 22:26 -0800
                Re: How do you remember the stack? Paul Rubin <no.email@nospam.invalid> - 2016-02-28 22:37 -0800
                Re: How do you remember the stack? hughaguilar96@gmail.com - 2016-02-28 19:11 -0800
                Re: How do you remember the stack? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-02-29 11:55 -0600
                Re: How do you remember the stack? "Elizabeth D. Rather" <erather@forth.com> - 2016-02-29 19:30 -1000
                Re: How do you remember the stack? "HAA" <someone@microsoft.com> - 2016-03-02 00:49 +1100
                Re: How do you remember the stack? "Elizabeth D. Rather" <erather@forth.com> - 2016-03-01 13:50 -1000
                Re: How do you remember the stack? Paul Rubin <no.email@nospam.invalid> - 2016-03-01 16:49 -0800
                Re: How do you remember the stack? hughaguilar96@gmail.com - 2016-03-01 18:04 -0800
                Re: How do you remember the stack? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-02 02:53 -0600
                Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-02 09:57 +0000
                Re: How do you remember the stack? Pablo Hugo Reda <pabloreda@gmail.com> - 2016-03-02 03:21 -0800
                Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-02 11:49 +0000
                Re: How do you remember the stack? Pablo Hugo Reda <pabloreda@gmail.com> - 2016-03-02 04:23 -0800
                Re: How do you remember the stack? stephen@mpeforth.com (Stephen Pelc) - 2016-03-02 18:32 +0000
                Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-02 18:41 +0000
                Re: How do you remember the stack? stephen@mpeforth.com (Stephen Pelc) - 2016-03-02 20:36 +0000
                Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-03 07:38 +0000
                Re: How do you remember the stack? stephen@mpeforth.com (Stephen Pelc) - 2016-03-03 09:26 +0000
                Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-03 11:15 +0000
                Re: How do you remember the stack? stephen@mpeforth.com (Stephen Pelc) - 2016-03-03 15:35 +0000
                Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-03 15:56 +0000
                Re: How do you remember the stack? stephen@mpeforth.com (Stephen Pelc) - 2016-03-03 17:04 +0000
                Re: How do you remember the stack? Whammo <sidciavic@gmail.com> - 2016-03-01 19:29 -0800
                Re: How do you remember the stack? Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-02-28 18:52 +0000
                Re: How do you remember the stack? Whammo <sidciavic@gmail.com> - 2016-02-28 13:30 -0800
                Re: How do you remember the stack? Lars Brinkhoff <lars.spam@nocrew.org> - 2016-02-29 07:55 +0100
                Re: How do you remember the stack? "Elizabeth D. Rather" <erather@forth.com> - 2016-02-29 19:34 -1000
                Re: How do you remember the stack? hughaguilar96@gmail.com - 2016-03-01 20:40 -0800
                Re: How do you remember the stack? Unknown <dog@gmail.com> - 2016-06-02 05:46 +0000
                Re: How do you remember the stack? Lars Brinkhoff <lars.spam@nocrew.org> - 2016-06-02 08:48 +0200
                Re: How do you remember the stack? hughaguilar96@gmail.com - 2016-06-02 00:17 -0700
                Re: How do you remember the stack? Michael Barry <barrym95838@yahoo.com> - 2016-06-02 19:48 -0700
                Re: How do you remember the stack? hughaguilar96@gmail.com - 2016-06-02 20:34 -0700
                Re: How do you remember the stack? "WJ" <w_a_x_man@yahoo.com> - 2016-02-22 19:23 +0000
                Re: How do you remember the stack? "HAA" <someone@microsoft.com> - 2016-02-25 20:31 +1100
                Re: How do you remember the stack? Julian Fondren <julian.fondren@gmail.com> - 2016-02-25 07:44 -0800
                Re: How do you remember the stack? Lars Brinkhoff <lars.spam@nocrew.org> - 2016-02-25 20:22 +0100
                Re: How do you remember the stack? "HAA" <someone@microsoft.com> - 2016-02-28 13:43 +1100
                Re: How do you remember the stack? "Elizabeth D. Rather" <erather@forth.com> - 2016-02-27 21:43 -1000
                Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-28 14:53 +0000
                Re: How do you remember the stack? hughaguilar96@gmail.com - 2016-02-28 15:27 -0800
                Re: How do you remember the stack? humptydumpty <ouatubi@gmail.com> - 2016-06-02 02:02 -0700
                Re: How do you remember the stack? JennyB <jennybrien@googlemail.com> - 2016-06-03 05:57 -0700
      Re: How do you remember the stack? Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-01 16:38 +0000
  Re: How do you remember the stack? Chris Curl <ccurl609@gmail.com> - 2016-02-12 16:31 -0800
  Re: How do you remember the stack? Whammo <sidciavic@gmail.com> - 2016-02-12 17:31 -0800
  Re: How do you remember the stack? Lars Brinkhoff <lars.spam@nocrew.org> - 2016-02-13 08:03 +0100
  Re: How do you remember the stack? dunno <dunno@dunno.dunno> - 2016-02-13 08:06 +0000
    Re: How do you remember the stack? minforth@arcor.de - 2016-02-13 01:50 -0800
      Re: How do you remember the stack? mhx@iae.nl - 2016-02-13 03:22 -0800
        Re: How do you remember the stack? Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-02-13 17:09 +0000
      Re: How do you remember the stack? mhx@iae.nl - 2016-02-13 03:39 -0800
      Re: How do you remember the stack? mhx@iae.nl - 2016-02-13 03:42 -0800
      Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-13 11:27 +0000
        Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-13 12:33 +0000
          Re: How do you remember the stack? minforth@arcor.de - 2016-02-15 01:05 -0800
      Re: How do you remember the stack? dunno <dunno@dunno.dunno> - 2016-02-14 19:34 +0000
  Re: How do you remember the stack? Julian Fondren <julian.fondren@gmail.com> - 2016-02-13 06:43 -0800
    Re: How do you remember the stack? minforth@arcor.de - 2016-02-15 01:22 -0800
      Re: How do you remember the stack? dunno <dunno@dunno.dunno> - 2016-02-15 09:48 +0000
      Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-15 09:53 +0000
        Re: How do you remember the stack? Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-02-15 11:26 +0000
          Re: How do you remember the stack? minforth@arcor.de - 2016-02-15 04:53 -0800
            Re: How do you remember the stack? dunno <dunno@dunno.dunno> - 2016-02-15 17:06 +0000
              Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-16 14:57 +0000
          Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-16 14:14 +0000
      Re: How do you remember the stack? Ron Aaron <rambamist@gmail.com> - 2016-02-15 12:31 +0200
      Re: How do you remember the stack? Jan Coombs <jenfhaomndgfwutc@murmic.plus.com> - 2016-02-18 22:53 +0000
  Re: How do you remember the stack? Doug Hoffman <glidedog@gmail.com> - 2016-02-13 10:51 -0500
  Re: How do you remember the stack? "HAA" <someone@microsoft.com> - 2016-02-14 10:18 +1100
  Re: How do you remember the stack? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-02-14 04:21 -0600
  Re: How do you remember the stack? Whammo <sidciavic@gmail.com> - 2016-02-20 14:36 -0800
    Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-21 16:35 +0000
      Re: How do you remember the stack? Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-02-21 18:34 +0000
        Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-22 09:52 +0000
          Re: How do you remember the stack? Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-02-22 13:07 +0000
            Re: How do you remember the stack? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-22 15:41 +0000
              Re: How do you remember the stack? "Elizabeth D. Rather" <erather@forth.com> - 2016-02-22 08:24 -1000
            Re: How do you remember the stack? "Elizabeth D. Rather" <erather@forth.com> - 2016-02-22 08:21 -1000
              Re: How do you remember the stack? hughaguilar96@gmail.com - 2016-02-22 17:51 -0800
                Re: How do you remember the stack? hughaguilar96@gmail.com - 2016-02-22 18:15 -0800
                Re: How do you remember the stack? "WJ" <w_a_x_man@yahoo.com> - 2016-02-29 06:20 +0000
                Re: How do you remember the stack? "WJ" <w_a_x_man@yahoo.com> - 2016-03-02 20:42 +0000
                Re: How do you remember the stack? "WJ" <w_a_x_man@yahoo.com> - 2016-06-02 20:13 +0000
  Re: How do you remember the stack? humptydumpty <ouatubi@gmail.com> - 2016-02-22 01:46 -0800

csiph-web