Sujet : Re: branch address architecture, not interactive use, The Design of Design
De : johnl (at) *nospam* taugh.com (John Levine)
Groupes : comp.archDate : 13. May 2024, 21:39:55
Autres entêtes
Organisation : Taughannock Networks
Message-ID : <v1ttqr$2095$1@gal.iecc.com>
References : 1 2 3 4
User-Agent : trn 4.0-test77 (Sep 1, 2010)
According to Thomas Koenig <
tkoenig@netcologne.de>:
Do we know who invented relative branches? The PDP-11 had them in 1969
but I don't think they were new then.
I am just trying to make sense of the little documentation there
is of the PDP-X, and it seems it would have had PC- relative
branches too (but also branches relative to index registers),
either with an 8-bit or a 16-bit offset. The Nova had something
similar, but only jumps relative to PC or its index registers,
the PDP-11 went to relative-only branches.
This draft is pretty clear:
https://bitsavers.org/pdf/dec/pdp-x/29_Nov67.pdfIt had both short page 0 addressing like the PDP-8 and short relative
long and short indexed.
I'd now say relative branches were obvious once you got to the point
where the cost of the addition to the PC wasn't a big deal, so they
probably occurred to a lot of people around the same time.
The PDP-11 had short relative branches and a long jump that could use
any address mode that made sense, typically absolute or indirect. The
Unix assembler had conditional jump pseudo-ops that turned into a
branch if the target was close enough or a reverse branch around a
jump otherwise. If you allow chaining branches to the same place,
coming up with an optimal set of long and short is NP complete. If you
just do long and short, you can get close enough by starting with
everything long and making passes over the code shortening the ones
you can until you can't shorten anything else. (I did that for the AIX
ROMP assembler, same deal.)
You could do some funky things with PDP-11 jumps like
JMP @(R4)+
which dispatched to the next routine of threaded code pointed to by R4.
-- Regards,John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",Please consider the environment before reading this e-mail. https://jl.ly
Date | Sujet | # | | Auteur |
21 Apr 24 | The Design of Design | 128 | | Thomas Koenig |
21 Apr 24 | Re: The Design of Design | 67 | | John Levine |
25 Apr 24 | Re: The Design of Design | 66 | | Thomas Koenig |
25 Apr 24 | Re: The Design of Design | 65 | | Stephen Fuld |
26 Apr 24 | Re: The Design of Design | 56 | | John Levine |
26 Apr 24 | Re: The Design of Design | 2 | | MitchAlsup1 |
26 Apr 24 | Re: The Design of Design | 1 | | John Levine |
26 Apr 24 | Re: The Design of Design | 50 | | Thomas Koenig |
26 Apr 24 | Re: The Design of Design | 1 | | Stephen Fuld |
26 Apr 24 | Re: The Design of Design | 47 | | John Levine |
27 Apr 24 | Re: The Design of Design | 4 | | Thomas Koenig |
27 Apr 24 | Re: PDP-10 addressing, was The Design of Design | 3 | | John Levine |
27 Apr 24 | Re: PDP-10 addressing, was The Design of Design | 2 | | MitchAlsup1 |
27 Apr 24 | Re: PDP-10 addressing, was The Design of Design | 1 | | John Levine |
30 Apr 24 | Re: The Design of Design | 42 | | MitchAlsup1 |
30 Apr 24 | Re: The Design of Design | 40 | | John Levine |
1 May 24 | Re: The Design of Design | 39 | | Tim Rentsch |
1 May 24 | Re: architecture, The Design of Design | 38 | | John Levine |
2 May 24 | Re: index architecture, The Design of Design | 1 | | John Levine |
2 May 24 | Re: architecture, The Design of Design | 4 | | Thomas Koenig |
3 May 24 | Re: architecture, The Design of Design | 1 | | MitchAlsup1 |
5 May 24 | Re: architecture, The Design of Design | 2 | | Thomas Koenig |
5 May 24 | Re: ancient 704 architecture, The Design of Design | 1 | | John Levine |
7 May 24 | Re: architecture, The Design of Design | 32 | | Tim Rentsch |
7 May 24 | Re: architecture, The Design of Design | 1 | | Thomas Koenig |
7 May 24 | Re: architecture, The Design of Design | 28 | | Michael S |
7 May 24 | Re: architecture, The Design of Design | 2 | | John Levine |
8 May 24 | Re: architecture, The Design of Design | 1 | | John Levine |
8 May 24 | Re: architecture, The Design of Design | 2 | | Tim Rentsch |
9 May 24 | Re: architecture, The Design of Design | 1 | | John Levine |
8 May 24 | Re: architecture, The Design of Design | 23 | | Thomas Koenig |
8 May 24 | Re: architecture, The Design of Design | 22 | | Michael S |
8 May 24 | Re: backward architecture, The Design of Design | 21 | | John Levine |
9 May 24 | Re: backward architecture, The Design of Design | 2 | | Lynn Wheeler |
10 May 24 | Re: backward architecture, The Design of Design | 1 | | Lynn Wheeler |
9 May 24 | Re: backward architecture, The Design of Design | 18 | | Michael S |
9 May 24 | Re: backward architecture, The Design of Design | 14 | | Thomas Koenig |
9 May 24 | Re: backward architecture, The Design of Design | 13 | | Michael S |
9 May 24 | Re: backward architecture, The Design of Design | 2 | | Anton Ertl |
9 May 24 | Re: backward architecture, The Design of Design | 1 | | Anton Ertl |
9 May 24 | Re: backward architecture, The Design of Design | 9 | | Stephen Fuld |
9 May 24 | Re: backward architecture, The Design of Design | 2 | | Michael S |
9 May 24 | Re: backward architecture, The Design of Design | 1 | | John Dallman |
10 May 24 | Re: backward architecture, The Design of Design | 6 | | Tim Rentsch |
10 May 24 | Re: backward architecture, The Design of Design | 5 | | Stephen Fuld |
30 May 24 | Re: backward architecture, The Design of Design | 4 | | Tim Rentsch |
30 May 24 | Re: backward architecture, The Design of Design | 3 | | Stephen Fuld |
30 May 24 | Re: backward architecture, The Design of Design | 2 | | Tim Rentsch |
31 May 24 | Re: backward architecture, The Design of Design | 1 | | John Levine |
10 May 24 | Re: backward architecture, The Design of Design | 1 | | Tim Rentsch |
10 May 24 | Re: backward architecture, The Design of Design | 1 | | John Levine |
10 May 24 | Re: backward architecture, The Design of Design | 2 | | Tim Rentsch |
10 May 24 | Re: backward architecture, The Design of Design | 1 | | John Levine |
7 May 24 | Re: architecture, The Design of Design | 2 | | Anton Ertl |
8 May 24 | Re: architecture, The Design of Design | 1 | | Tim Rentsch |
30 Apr 24 | Re: The Design of Design | 1 | | MitchAlsup1 |
30 Apr 24 | Re: what's a register, The Design of Design | 1 | | John Levine |
26 Apr 24 | Re: The Design of Design | 3 | | Stephen Fuld |
26 Apr 24 | Re: The Design of Design | 2 | | John Levine |
26 Apr 24 | Re: The Design of Design | 1 | | Stephen Fuld |
27 Apr 24 | Re: The Design of Design | 7 | | Thomas Koenig |
27 Apr 24 | Re: The Design of Design | 1 | | Stephen Fuld |
27 Apr 24 | Re: The Design of Design | 2 | | John Levine |
27 Apr 24 | Re: The Design of Design | 1 | | Thomas Koenig |
28 Apr 24 | Re: The Design of Design | 3 | | Tim Rentsch |
29 Apr 24 | Re: antitrust history, The Design of Design | 2 | | John Levine |
1 May 24 | Re: antitrust history, The Design of Design | 1 | | Tim Rentsch |
29 Apr 24 | Re: The Design of Design | 1 | | Tim Rentsch |
29 Apr 24 | Re: The Design of Design | 60 | | Tim Rentsch |
1 May 24 | Re: The Design of Design | 59 | | Stephen Fuld |
1 May 24 | Re: JCL, The Design of Design | 3 | | John Levine |
1 May 24 | Re: JCL, The Design of Design | 2 | | Stephen Fuld |
1 May 24 | Re: JCL, The Design of Design | 1 | | Stephen Fuld |
1 May 24 | Re: The Design of Design | 1 | | MitchAlsup1 |
1 May 24 | Re: The Design of Design | 1 | | Thomas Koenig |
7 May 24 | Re: The Design of Design | 53 | | Tim Rentsch |
7 May 24 | Re: The Design of Design | 45 | | Stephen Fuld |
7 May 24 | Re: The Design of Design | 1 | | Thomas Koenig |
7 May 24 | Re: The Design of Design | 33 | | Stephen Fuld |
7 May 24 | Re: The Design of Design | 29 | | Thomas Koenig |
7 May 24 | Re: The Design of Design | 28 | | Stephen Fuld |
7 May 24 | Re: interative use, The Design of Design | 25 | | John Levine |
7 May 24 | Re: interative use, The Design of Design | 4 | | MitchAlsup1 |
8 May 24 | Re: third system syndrome, interactive use, The Design of Design | 3 | | John Levine |
8 May 24 | Re: third system syndrome, interactive use, The Design of Design | 2 | | Lynn Wheeler |
9 May 24 | Re: third system syndrome, interactive use, The Design of Design | 1 | | Lynn Wheeler |
8 May 24 | Re: interative use, The Design of Design | 20 | | Stephen Fuld |
8 May 24 | Re: interative use, The Design of Design | 19 | | John Levine |
9 May 24 | Re: interative use, The Design of Design | 18 | | Stephen Fuld |
10 May 24 | Re: address architecture, not interactive use, The Design of Design | 17 | | John Levine |
10 May 24 | Re: address architecture, not interactive use, The Design of Design | 1 | | Stephen Fuld |
11 May 24 | Re: address architecture, not interactive use, The Design of Design | 15 | | Thomas Koenig |
11 May 24 | Re: address architecture, not interactive use, The Design of Design | 3 | | MitchAlsup1 |
12 May 24 | Re: address architecture, not interactive use, The Design of Design | 2 | | Thomas Koenig |
13 May 24 | Re: address architecture, not interactive use, The Design of Design | 1 | | MitchAlsup1 |
11 May 24 | Re: branch address architecture, not interactive use, The Design of Design | 11 | | John Levine |
12 May 24 | Re: branch address architecture, not interactive use, The Design of Design | 10 | | Thomas Koenig |
13 May 24 | Re: branch address architecture, not interactive use, The Design of Design | 9 | | John Levine |
13 May 24 | Re: branch address architecture, not interactive use, The Design of Design | 8 | | Thomas Koenig |
13 May 24 | Re: branch address architecture, not interactive use, The Design of Design | 7 | | John Levine |
13 May 24 | Re: branch address architecture, not interactive use, The Design of Design | 4 | | MitchAlsup1 |
14 May 24 | Re: branch address architecture, not interactive use, The Design of Design | 1 | | Thomas Koenig |
25 May 24 | Re: branch address architecture, not interactive use, The Design of Design | 1 | | Anton Ertl |
8 May 24 | Re: The Design of Design | 2 | | Thomas Koenig |
10 May 24 | Re: The Design of Design | 3 | | Tim Rentsch |
30 May 24 | Re: The Design of Design | 10 | | Tim Rentsch |
7 May 24 | Re: The Design of Design | 7 | | Thomas Koenig |