Groups > comp.lang.forth > #19254

Re: About stack access profundity

From	stephenXXX@mpeforth.com (Stephen Pelc)
Newsgroups	comp.lang.forth
Subject	Re: About stack access profundity
Message-ID	<5107ff7c.353609431@192.168.0.50> (permalink)
References	(4 earlier) <2013Jan29.092047@mips.complang.tuwien.ac.at> <zMSdnRyTx7zjCJrMnZ2dnUVZ_qmdnZ2d@supernews.com> <2013Jan29.104748@mips.complang.tuwien.ac.at> <JIidnQ2d7p40AprMnZ2dnUVZ_oSdnZ2d@supernews.com> <2013Jan29.162133@mips.complang.tuwien.ac.at>
Date	2013-01-29 17:06 +0000

Show all headers | View raw

On Tue, 29 Jan 2013 15:21:33 GMT, anton@mips.complang.tuwien.ac.at
(Anton Ertl) wrote:

>That depends on the way in which the code is factored.  The one that I
>had in mind was your suggestion of storing the stuff in memory and
>passing addresses; not sure if it results in better-factored code, but
>a decent compiler will produce slower code for that than for a version
>using constant PICKs.

Nearly all PICKs that I have seen have used a literal index.

What happens is that PICKs produce fetches indexed from the data
stack pointer, and (assuming that the code generator gets the
structure address into a register) the structure is accessed as
offsets from a base register. If an item on the stack is DUPped
or OVERred, it's usually a big hint to a compiler that the item
should be in a register.

When we rewrote our PowerView embedded GUI to pass structures rather
than than keep graphics coordinates on the stack, the code (for ARM
and Cortex) became shorter and faster. In our experience, your
assertion does not hold bcause the use of structures considerably
reduces the stack traffic.

I'm prepared to be convinced that there are conditions under which
our experience does not hold.

Stephen

-- 
Stephen Pelc, stephenXXX@mpeforth.com
MicroProcessor Engineering Ltd - More Real, Less Time
133 Hill Lane, Southampton SO15 5AF, England
tel: +44 (0)23 8063 1441, fax: +44 (0)23 8033 9691
web: http://www.mpeforth.com - free VFX Forth downloads

Thread

About stack access profundity Pablo Hugo Reda <pabloreda@gmail.com> - 2013-01-27 12:11 -0800
  Re: About stack access profundity humptydumpty <ouatubi@gmail.com> - 2013-01-28 00:59 -0800
    Re: About stack access profundity Pablo Hugo Reda <pabloreda@gmail.com> - 2013-01-28 07:17 -0800
  Re: About stack access profundity Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-28 03:10 -0600
    Re: About stack access profundity Pablo Hugo Reda <pabloreda@gmail.com> - 2013-01-28 07:23 -0800
      Re: About stack access profundity Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-28 10:46 -0600
        Re: About stack access profundity anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-29 08:20 +0000
          Re: About stack access profundity Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-29 03:25 -0600
            Re: About stack access profundity anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-29 09:47 +0000
              Re: About stack access profundity Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-29 04:08 -0600
                Re: About stack access profundity anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-29 15:21 +0000
                Re: About stack access profundity Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-29 09:57 -0600
                Re: About stack access profundity anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-29 17:01 +0000
                Re: About stack access profundity Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-29 12:22 -0600
                Re: About stack access profundity anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-30 17:40 +0000
                Re: About stack access profundity Paul Rubin <no.email@nospam.invalid> - 2013-01-30 11:49 -0800
                Re: About stack access profundity anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-02-04 16:39 +0000
                Re: About stack access profundity Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-30 16:32 -0600
                Re: About stack access profundity anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-31 16:02 +0000
                Re: About stack access profundity stephenXXX@mpeforth.com (Stephen Pelc) - 2013-01-29 17:06 +0000
                Re: About stack access profundity anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-29 17:58 +0000
                Re: About stack access profundity Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-29 12:29 -0600
                Re: About stack access profundity anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-30 17:22 +0000
                Re: About stack access profundity Bernd Paysan <bernd.paysan@gmx.de> - 2013-01-29 20:17 +0100
                Re: About stack access profundity mhx@iae.nl (Marcel Hendrix) - 2013-01-29 21:44 +0200
                Re: About stack access profundity Bernd Paysan <bernd.paysan@gmx.de> - 2013-01-29 22:14 +0100
                Re: About stack access profundity anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-30 16:29 +0000
                Re: About stack access profundity Pablo Hugo Reda <pabloreda@gmail.com> - 2013-01-30 09:58 -0800
                Re: About stack access profundity stephenXXX@mpeforth.com (Stephen Pelc) - 2013-01-31 12:32 +0000
                Re: About stack access profundity Bernd Paysan <bernd.paysan@gmx.de> - 2013-01-31 15:37 +0100
                Re: About stack access profundity Mark Wills <forthfreak@gmail.com> - 2013-01-29 23:12 -0800
          Re: About stack access profundity stephenXXX@mpeforth.com (Stephen Pelc) - 2013-01-29 10:08 +0000
            Re: About stack access profundity Pablo Hugo Reda <pabloreda@gmail.com> - 2013-01-29 07:10 -0800
            Re: About stack access profundity anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-29 15:17 +0000
      Re: About stack access profundity Mark Wills <forthfreak@gmail.com> - 2013-01-29 00:57 -0800
  Re: About stack access profundity Mark Wills <forthfreak@gmail.com> - 2013-01-28 01:56 -0800
  Re: About stack access profundity anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-29 15:30 +0000
    Re: About stack access profundity Pablo Hugo Reda <pabloreda@gmail.com> - 2013-01-29 09:06 -0800
  Re: About stack access profundity Pablo Hugo Reda <pabloreda@gmail.com> - 2013-02-03 06:22 -0800
    Re: About stack access profundity Mark Wills <forthfreak@gmail.com> - 2013-02-03 07:25 -0800
      Re: About stack access profundity Pablo Hugo Reda <pabloreda@gmail.com> - 2013-02-03 15:51 -0800
        Re: About stack access profundity Coos Haak <chforth@hccnet.nl> - 2013-02-04 01:12 +0100
    Re: About stack access profundity Mark Wills <forthfreak@gmail.com> - 2013-02-03 23:10 -0800
      Re: About stack access profundity Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-02-04 03:26 -0600
  Re: About stack access profundity humptydumpty <ouatubi@gmail.com> - 2013-02-03 11:26 -0800
    Re: About stack access profundity Pablo Hugo Reda <pabloreda@gmail.com> - 2013-02-03 15:49 -0800

csiph-web