From: Sergey Belyashov <sergey.belyashov@gmail.com>
To: Sergey Belyashov via Cgen <cgen@sourceware.org>
Subject: Re: BUG: non-fixed-length ISAs are unsupported for now
Date: Thu, 30 Jul 2020 12:11:43 +0300 [thread overview]
Message-ID: <CAOe0RDxwHg4GZigSOm1c9xWafriO=WEAh=U6T3QhR4uLbgBfrA@mail.gmail.com> (raw)
In-Reply-To: <CAOe0RDywVAHVfwZhAwvJhdSYHf5nmbXwsWpZVLf90xxY3tgUKg@mail.gmail.com>
Hi,
Can anybody help me, how to correctly implement Zilog Z80 (and
derivatives) instruction decode table switching in CGEN? For example,
the main table has 1 byte instruction and possibly 1-2 bytes of
immediate operand. There are four (ez80 has eight) pseudo instructions
which switches tables for current instruction:
* 0xCB - next byte is rotation or bit manipulation instruction code,
no optional operands;
* 0xED - next byte is instruction of extended instruction set,
possible 1-2 bytes of immediate operand;
* 0xDD/0xFD - switches use of H, L and HL registers to IX/IY on main
and 0xCB tables (here is difficult, because always added immediate
before instruction code: 0xDD 0xCB 0x07 0x3E - "srl (ix+7)").
I think, it should be done in following way:
* it is need to create 5 ISAs: isa_00, isa_cb, isa_ed, isa_ii_00, isa_ii_cb
* opcodes 0xCB, 0xDD, 0xED, 0xFD just switches ISA for current instruction
* <I do not know what I need to do for assembler support, how to parse
by all tables>
Best regards,
Sergey Belyashov
next prev parent reply other threads:[~2020-07-30 9:11 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-23 13:37 Sergey Belyashov
2020-04-27 16:29 ` Frank Ch. Eigler
2020-04-27 17:00 ` Sergey Belyashov
2020-04-27 17:52 ` Sergey Belyashov
2020-04-27 18:03 ` Jose E. Marchesi
2020-04-27 19:34 ` Sergey Belyashov
2020-04-27 20:01 ` Jose E. Marchesi
2020-04-27 20:23 ` Sergey Belyashov
2020-04-29 19:11 ` Sergey Belyashov
2020-07-30 9:11 ` Sergey Belyashov [this message]
2020-08-11 15:38 ` Frank Ch. Eigler
2020-08-11 15:57 ` Sergey Belyashov
2020-08-11 16:08 ` Frank Ch. Eigler
2020-08-12 13:59 ` Sergey Belyashov
2020-08-12 18:36 ` Frank Ch. Eigler
2020-08-12 18:53 ` Jose E. Marchesi
2020-08-12 19:19 ` Sergey Belyashov
2020-08-12 19:21 ` Frank Ch. Eigler
2020-08-12 19:27 ` Jose E. Marchesi
2020-08-12 19:44 ` Sergey Belyashov
2020-08-12 19:57 ` Frank Ch. Eigler
2020-08-13 13:34 ` Sergey Belyashov
2020-08-13 14:32 ` Frank Ch. Eigler
2020-08-13 14:47 ` Sergey Belyashov
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='CAOe0RDxwHg4GZigSOm1c9xWafriO=WEAh=U6T3QhR4uLbgBfrA@mail.gmail.com' \
--to=sergey.belyashov@gmail.com \
--cc=cgen@sourceware.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 read-only IMAP folder(s) and NNTP newsgroup(s).