From: "Frank Ch. Eigler" <fche@redhat.com>
To: Alan Lehotsky <apl@alum.mit.edu>
Cc: cgen@sources.redhat.com
Subject: Re: contemplating CGEN for VLIW architecture
Date: Wed, 20 Feb 2002 07:59:00 -0000 [thread overview]
Message-ID: <20020220105947.C3652@redhat.com> (raw)
In-Reply-To: <p04330100b89964fb3501@[192.168.1.254]>; from apl@alum.mit.edu on Wed, Feb 20, 2002 at 09:44:45AM -0500
[-- Attachment #1: Type: text/plain, Size: 1129 bytes --]
Hi -
On Wed, Feb 20, 2002 at 09:44:45AM -0500, Alan Lehotsky wrote:
> I'm evaluating a possible port to a VLIW microsequencer (256 bit
> microword, 25 fields per micro-instruction).
It may be best to model this as a list of independent subinstructions,
one for each logical operation. Let each have its own cgen isa tag.
(Let another layer take care of bitfield packing / unpacking.)
Otherwise, you might have to ask cgen to expand the cartesian product
of all possible opcode tuples, to come up with the total list of
cgen-level instructions.
(Let some other layer take care of bitwise packing / unpacking.)
The 32-bit limit you mention relates to something a little different:
the width of the bitmask used to identify a given single cgen instruction.
In this case, if you break up the VLIW word into N subinstructions, the
32-bit limit may end up not affecting you.
> I guess I'm also wondering if I can build an assembler that looks more
> like an expression language, viz something like
> REGA = REGB + REGC, if R7 > R8 jump FAIL, REGZ=0x100;
> [...]
Mucho worko, amigo.
- FChE
[-- Attachment #2: Type: application/pgp-signature, Size: 232 bytes --]
next prev parent reply other threads:[~2002-02-20 15:59 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-02-20 6:54 Alan Lehotsky
2002-02-20 6:59 ` matthew green
2002-02-20 8:01 ` John Healy
2002-02-20 7:59 ` Frank Ch. Eigler [this message]
2002-02-20 9:18 ` Doug Evans
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=20020220105947.C3652@redhat.com \
--to=fche@redhat.com \
--cc=apl@alum.mit.edu \
--cc=cgen@sources.redhat.com \
/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 read-only IMAP folder(s) and NNTP newsgroup(s).