From: Tsukasa OI <research_trasio@irq.a4lg.com>
To: Jan Beulich <jbeulich@suse.com>, Binutils <binutils@sourceware.org>
Subject: Re: [PATCH v2] RISC-V: Add support for 'Zacas' atomic CAS
Date: Tue, 24 Oct 2023 13:07:37 +0900 [thread overview]
Message-ID: <df7079de-6dd5-4b20-8753-377968619d13@irq.a4lg.com> (raw)
In-Reply-To: <ea818aaa-fd25-c549-62e0-43c974959726@suse.com>
On 2023/10/23 15:47, Jan Beulich wrote:
>
> Mind me asking what good the former of the two really does? It's just
> match_opcode() aiui, properly obfuscated.
>
> Jan
>
****Excuse me?****
As a single patch set, I think Gianluca's patch with a minor fix will
work perfectly. But, the concept of register pairs / register groups
are not specific to 'Zacas', that's what I'm talking about and the
reason I think Gianluca's patch set's match function will not be a long
term solution (actually, I found Gianluca's patch set after I wrote
mine, but that wouldn't change my opinion).
So, let me list all register group-related constraints in existing and
upcoming extensions (except all ones; x is "not applicable" and can be
theoretically replaced to "1" but it's probably better to be named "x"
to indicate that the instruction does not use "x" operand as register):
Extension | RD | RS1 | RS2 | RS3
----------- | --- | --- | --- | ---
Zdinx | 2 | 2 | 2 | x
Zdinx | 2 | 2 | 2 | 2
Zdinx | x | 2 | 2 | x
Zdinx | 1 | 2 | x | x
Zdinx | 2 | 1 | x | x
Zdinx | 2 | 2 | x | x
----------- | --- | --- | --- | ---
Zqinx | 2 | 2 | 2 | x
Zqinx | 4 | 4 | 4 | x
Zqinx | 2 | 2 | 2 | 2
Zqinx | 4 | 4 | 4 | 4
Zqinx | x | 2 | 2 | x
Zqinx | x | 4 | 4 | x
Zqinx | 1 | 2 | x | x
Zqinx | 1 | 4 | x | x
Zqinx | 2 | 1 | x | x
Zqinx | 2 | 2 | x | x
Zqinx | 2 | 4 | x | x
Zqinx | 4 | 1 | x | x
Zqinx | 4 | 2 | x | x
Zqinx | 4 | 4 | x | x
----------- | --- | --- | --- | ---
Zpsfoperand | 2 | 1 | 1 | x
Zpsfoperand | 2 | 2 | 1 | x
Zpsfoperand | 2 | 2 | 2 | x
----------- | --- | --- | --- | ---
Zacas | 2 | 1 | 2 | x
Lots of similar constraints but different values. Don't you think a
generator macro is the best solution for this kind of situation?
Tsukasa
next prev parent reply other threads:[~2023-10-24 4:07 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-21 3:12 [PATCH 0/1] " Tsukasa OI
2023-10-21 3:12 ` [PATCH 1/1] " Tsukasa OI
2023-10-22 3:54 ` [PATCH v2] " Tsukasa OI
2023-10-22 3:57 ` [REVIEW ONLY] UNRATIFIED RISC-V: Add support for 'Zabha' subword AMO extension Tsukasa OI
2023-10-22 3:59 ` [PATCH v2] RISC-V: Add support for 'Zacas' atomic CAS Tsukasa OI
2023-10-23 6:47 ` Jan Beulich
2023-10-24 4:07 ` Tsukasa OI [this message]
2023-10-24 6:02 ` Jan Beulich
2023-10-25 2:15 ` Nelson Chu
2023-10-25 6:02 ` Jan Beulich
2023-12-06 18:39 ` [PATCH 0/1] " Gianluca Guida
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=df7079de-6dd5-4b20-8753-377968619d13@irq.a4lg.com \
--to=research_trasio@irq.a4lg.com \
--cc=binutils@sourceware.org \
--cc=jbeulich@suse.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).