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Groups > comp.lang.forth > #32904

Re: ANS Forth test programs

Newsgroups comp.lang.forth
Date 2014-08-10 03:19 -0700
References (14 earlier) <0009206c-2d60-481e-a1d5-3b3cc0c86ccc@googlegroups.com> <8dc7b116-942e-4616-84b2-bba34f34e033@googlegroups.com> <dsidnSuCZrgrcXjOnZ2dnUU7-eudnZ2d@supernews.com> <ab0a480a-e37c-4f3c-a636-8799522735a1@googlegroups.com> <f82dnb2dG5P7sXrOnZ2dnUU7-WudnZ2d@supernews.com>
Message-ID <b1a586da-9ffa-4286-aad0-e7f97ed67306@googlegroups.com> (permalink)
Subject Re: ANS Forth test programs
From Raimond Dragomir <raimond.dragomir@gmail.com>

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duminică, 10 august 2014, 11:25:10 UTC+3, Andrew Haley a scris:
> hughaguilar96@yahoo.com wrote:
> 
> > On Saturday, August 9, 2014 2:41:10 AM UTC-7, Andrew Haley wrote:
> 
> >> Raimond Dragomir <raimond.dragomir@gmail.com> wrote:
> 
> >> 
> 
> >> > SwiftForth V2 align which doesn't aligned seems to be just a
> 
> >> > compiler bug. Even if the hardware doesn't care, ALIGN should align,
> 
> >> > because it is its function. If the forth standard permits this (I
> 
> >> > don't know) than the standard is just a toy. If it's not permitting
> 
> >> > this, then SwiftForth V2 just has a bug.
> 
> > 
> 
> >> Hardware which doesn't care has an alignment of 1.  ALIGN does align
> 
> >> on such hardware, with alignment 1.
> 
> > 
> 
> > This is so much baloney! The concept of alignment has always meant
> 
> > alignment to the cell size (register size).
> 
> 
> 
> Actually, no.  In the past there was no need to align to the cell size
> 
> on many processors.  Then came processors which required strict
> 
> alignment and some which were faster with aligned cells.  With the
> 
> fomer, ALIGN must cell-align, and with the latter it's an
> 
> implementation decision.
> 
> 
> 
> > The only processors that have an alignment of 1 are the 8-bit
> 
> > processors such as the 65c02 and Z80 that have 1-byte registers and
> 
> > an 8-bit data-bus.
> 
> 
> 
> So, 1-aligning is a sensible choice on such parts.
> 
> 
> 
> > On some processors (the x86), accessing an unaligned address will
> 
> > work inefficiently. This is extremely inefficient on the 16-bit x86
> 
> > (except the 8088 that has an 8-bit data-bus), but doesn't really
> 
> > matter that much on the later processors (so long as you are not
> 
> > overlapping cache-lines, there shouldn't be any inefficiency). So,
> 
> > on the 80486 the hardware does "care," but on the modern x86 the
> 
> > hardware doesn't "care"
> 
> 
> 
> That's right: unless a cell in memory straddles a cache line it makes
> 
> no difference.  However, when it does straddle a cache line there is a
> 
> penalty.  For that reason I'd align cells in structs on modern x86
> 
> hardware.
> 
> 
> 
> So, in summary: my statment, which was
> 
> 
> 
> >> Hardware which doesn't care has an alignment of 1.  ALIGN does align
> 
> >> on such hardware, with alignment 1.
> 
> 
> 
> is entirely true.
> 
> 
> 
> Andrew.

In my view, aligning is a clear concept. Usually the boundary is explicit. When not, it is some default, like cell size, register size or just 1 (no aligning).

Personally I thought that the forth align is on the forth cell size. It seems not, at least by the ans standard.

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Thread

ANS Forth test programs Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-08-03 23:34 +0100
  Re: ANS Forth test programs mhx@iae.nl - 2014-08-03 22:33 -0700
    Re: ANS Forth test programs Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-08-04 08:47 +0100
      Re: ANS Forth test programs "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-08-04 05:10 -0400
        Re: ANS Forth test programs Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-08-05 17:33 +0100
      Re: ANS Forth test programs stephenXXX@mpeforth.com (Stephen Pelc) - 2014-08-21 16:01 +0000
        Re: ANS Forth test programs anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-21 16:20 +0000
          Re: ANS Forth test programs stephenXXX@mpeforth.com (Stephen Pelc) - 2014-08-21 21:47 +0000
            Re: ANS Forth test programs anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-22 12:33 +0000
          Re: ANS Forth test programs albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-08-22 19:23 +0000
        Re: ANS Forth test programs Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-08-22 12:28 +0100
          Re: ANS Forth test programs "Alex McDonald" <blog@rivadpm.com> - 2014-08-22 13:35 +0100
            Re: ANS Forth test programs Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-08-22 17:11 +0100
          Re: ANS Forth test programs anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-22 12:47 +0000
    Re: ANS Forth test programs Bernd Paysan <bernd.paysan@gmx.de> - 2014-08-04 14:26 +0200
      Re: ANS Forth test programs Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-08-05 17:35 +0100
        Re: ANS Forth test programs hughaguilar96@yahoo.com - 2014-08-05 20:06 -0700
          Re: ANS Forth test programs "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-08-06 16:43 -0400
          Re: ANS Forth test programs Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-08-07 10:23 +0100
            Re: ANS Forth test programs hughaguilar96@yahoo.com - 2014-08-07 18:29 -0700
              Re: ANS Forth test programs "Alex McDonald" <blog@rivadpm.com> - 2014-08-07 23:28 -0700
                Re: ANS Forth test programs Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-08 04:25 -0500
                Re: ANS Forth test programs Raimond Dragomir <raimond.dragomir@gmail.com> - 2014-08-08 08:08 -0700
                Re: ANS Forth test programs Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-08 10:49 -0500
                Re: ANS Forth test programs hughaguilar96@yahoo.com - 2014-08-08 19:54 -0700
                Re: ANS Forth test programs anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-08 16:27 +0000
                Re: ANS Forth test programs Raimond Dragomir <raimond.dragomir@gmail.com> - 2014-08-08 10:47 -0700
                Re: ANS Forth test programs Coos Haak <chforth@hccnet.nl> - 2014-08-08 22:34 +0200
                Re: ANS Forth test programs Raimond Dragomir <raimond.dragomir@gmail.com> - 2014-08-08 21:06 -0700
                Re: ANS Forth test programs hughaguilar96@yahoo.com - 2014-08-08 23:59 -0700
                Re: ANS Forth test programs Raimond Dragomir <raimond.dragomir@gmail.com> - 2014-08-09 01:35 -0700
                Re: ANS Forth test programs Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-09 04:41 -0500
                Re: ANS Forth test programs hughaguilar96@yahoo.com - 2014-08-09 17:53 -0700
                Re: ANS Forth test programs Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-10 03:25 -0500
                Re: ANS Forth test programs Raimond Dragomir <raimond.dragomir@gmail.com> - 2014-08-10 03:19 -0700
                Re: ANS Forth test programs Mikael Nordman <oh2aun@gmail.com> - 2014-08-10 05:28 -0700
                Re: ANS Forth test programs Raimond Dragomir <raimond.dragomir@gmail.com> - 2014-08-12 22:43 -0700
                Re: ANS Forth test programs stephenXXX@mpeforth.com (Stephen Pelc) - 2014-08-13 09:46 +0000
                Re: ANS Forth test programs hughaguilar96@yahoo.com - 2014-08-13 21:17 -0700
                Re: ANS Forth test programs stephenXXX@mpeforth.com (Stephen Pelc) - 2014-08-14 10:24 +0000
                Re: ANS Forth test programs "Alex McDonald" <blog@rivadpm.com> - 2014-08-14 12:10 +0100
                Re: ANS Forth test programs Raimond Dragomir <raimond.dragomir@gmail.com> - 2014-08-14 06:02 -0700
                Re: ANS Forth test programs stephenXXX@mpeforth.com (Stephen Pelc) - 2014-08-14 23:48 +0000
                Re: ANS Forth test programs hughaguilar96@yahoo.com - 2014-08-14 20:06 -0700
                Re: ANS Forth test programs stephenXXX@mpeforth.com (Stephen Pelc) - 2014-08-15 09:13 +0000
                Re: ANS Forth test programs hughaguilar96@yahoo.com - 2014-08-15 21:07 -0700
                Re: ANS Forth test programs Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-16 02:22 -0500
                Re: ANS Forth test programs "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-08-16 04:43 -0400
                Re: ANS Forth test programs stephenXXX@mpeforth.com (Stephen Pelc) - 2014-08-16 20:37 +0000
                Re: ANS Forth test programs BruceMcF <agila61@netscape.net> - 2014-08-12 16:55 -0700
                Re: ANS Forth test programs Raimond Dragomir <raimond.dragomir@gmail.com> - 2014-08-12 22:47 -0700
                Re: ANS Forth test programs "Alex McDonald" <blog@rivadpm.com> - 2014-08-13 10:43 +0100
                Re: ANS Forth test programs bruce.mcfarling@gmail.com - 2014-08-16 10:02 -0700
                Re: ANS Forth test programs anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-09 11:09 +0000
                Re: ANS Forth test programs Lars Brinkhoff <lars.spam@nocrew.org> - 2014-08-09 13:34 +0200
                Re: ANS Forth test programs Bernd Paysan <bernd.paysan@gmx.de> - 2014-08-09 21:45 +0200
                Re: ANS Forth test programs hughaguilar96@yahoo.com - 2014-08-08 13:39 -0700
                Re: ANS Forth test programs "Alex McDonald" <blog@rivadpm.com> - 2014-08-10 03:21 +0100
                Re: ANS Forth test programs "Bill Leary" <Bill_Leary@msn.com> - 2014-08-08 10:34 -0400
              Re: ANS Forth test programs Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-08-08 10:18 +0100
                Re: ANS Forth test programs hughaguilar96@yahoo.com - 2014-08-08 12:48 -0700
                Re: ANS Forth test programs Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-08-08 21:46 +0100
                Re: ANS Forth test programs hughaguilar96@yahoo.com - 2014-08-08 14:14 -0700
                Re: ANS Forth test programs Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-08-08 23:06 +0100
                Re: ANS Forth test programs Coos Haak <chforth@hccnet.nl> - 2014-08-09 00:40 +0200
                Re: ANS Forth test programs hughaguilar96@yahoo.com - 2014-08-08 18:17 -0700
  Re: ANS Forth test programs hughaguilar96@yahoo.com - 2014-08-06 14:50 -0700
    Re: ANS Forth test programs Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-08-07 10:12 +0100
      Re: ANS Forth test programs hughaguilar96@yahoo.com - 2014-08-07 16:07 -0700
  Re: ANS Forth test programs francois.ganza@wanadoo.fr - 2014-08-08 13:40 -0700

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