From: Paul Ruizendaal <pnr@planet.nl>
To: TUHS main list <tuhs@minnie.tuhs.org>
Subject: Re: [TUHS] Memory management in Dennis Ritchie's C Compiler
Date: Thu, 27 Aug 2020 10:37:58 +0200 [thread overview]
Message-ID: <91C9F0D7-181D-4677-AFCD-155D45858788@planet.nl> (raw)
Doug,
“In fact Dennis's compiler did not use AID instructions for that purpose.”
Whilst local variables are indeed accessed as an offset from the base pointer, I’m not sure that the above statement is correct. In the V6 compiler (-sp) was certainly used to push arguments to the stack, and when the register allocation overflowed, the interim results were pushed to the stack as well with (-sp).
See c10.c, the case CALL in rcexpr(), the function comarg() and sptab (which is right at the end of table.s)
Links:
https://www.tuhs.org/cgi-bin/utree.pl?file=V6/usr/source/c/c10.c
https://www.tuhs.org/cgi-bin/utree.pl?file=V6/usr/source/c/table.s
For interim result pushing/popping I refer to the FS and SS macro’s. Dennis discusses these in his “A tour of the C compiler” paper.
https://www.jslite.net/cgi-bin/9995/doc/tip/doc/old-ctour.pdf
Of course this is all implementational detail, not a core design aspect - as Richard Miller showed in his port to the Interdata architecture (including a port of the Ritchie C compiler). Maybe the sentence should have read: "In fact Dennis's compiler did not rely on having AID instructions for that purpose."
Paul
@Warren: at moments like these I really like having the line highlight feature that we discussed before Summer.
next reply other threads:[~2020-08-27 8:52 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-27 8:37 Paul Ruizendaal [this message]
-- strict thread matches above, loose matches on Subject: below --
2020-08-26 15:59 Noel Chiappa
2020-08-26 16:09 ` Warner Losh
2020-08-26 19:13 ` Clem Cole
2020-08-26 16:14 ` Jim Geist
2020-08-26 17:31 ` John Cowan
2020-08-26 13:24 Doug McIlroy
2020-08-26 15:41 ` John Cowan
2020-08-25 9:36 Steve Simon
2020-08-17 22:32 Norman Wilson
2020-08-17 22:55 ` Bakul Shah
2020-08-17 23:12 ` Chet Ramey
2020-08-18 6:33 ` arnold
2020-08-17 19:51 Noel Chiappa
2020-08-17 19:27 Noel Chiappa
2020-08-17 19:30 ` Larry McVoy
2020-08-17 19:44 ` Dan Halbert
2020-08-17 19:50 ` Paul Winalski
2020-08-17 22:05 ` Arthur Krewat
2020-08-18 0:52 ` Rob Gingell
2020-08-17 2:02 Noel Chiappa
2020-08-17 18:02 ` Paul Winalski
2020-08-17 18:13 ` Jim Geist
2020-08-17 18:48 ` Paul Winalski
2020-08-17 19:08 ` Jim Geist
2020-08-17 19:28 ` Paul Winalski
2020-08-17 19:35 ` Jim Geist
2020-08-17 19:41 ` Richard Salz
2020-08-17 23:40 ` Steffen Nurpmeso
2020-08-15 21:50 Dibyendu Majumdar
2020-08-16 15:20 ` arnold
2020-08-16 15:27 ` Jim Geist
2020-08-17 16:13 ` Dan Cross
2020-08-17 20:16 ` Dibyendu Majumdar
2020-08-17 20:34 ` Paul Winalski
2020-08-17 20:43 ` Dibyendu Majumdar
2020-08-17 21:05 ` Warner Losh
2020-08-17 22:47 ` Dave Horsfall
2020-08-17 23:06 ` Nemo Nusquam
2020-08-17 21:29 ` Dibyendu Majumdar
2020-08-24 15:58 ` Dan Cross
2020-08-24 17:08 ` John Cowan
2020-08-24 17:15 ` Clem Cole
2020-08-24 17:24 ` Clem Cole
2020-08-24 17:20 ` Dan Cross
2020-08-25 23:06 ` Arthur Krewat
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=91C9F0D7-181D-4677-AFCD-155D45858788@planet.nl \
--to=pnr@planet.nl \
--cc=tuhs@minnie.tuhs.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).