public inbox for gcc-patches@gcc.gnu.org
 help / color / mirror / Atom feed
From: Palmer Dabbelt <palmer@dabbelt.com>
To: gcc-patches@gcc.gnu.org
Cc: research_trasio@irq.a4lg.com, gcc-patches@gcc.gnu.org
Subject: Re: [PATCH v3 1/1] RISC-V: Add support for 'XVentanaCondOps' reusing 'Zicond' support
Date: Tue, 05 Sep 2023 20:16:25 -0700 (PDT)	[thread overview]
Message-ID: <mhng-cd3c8f43-17ed-41b7-8a8e-5cb364a9a500@palmer-ri-x1c9> (raw)
In-Reply-To: <a24e5872-77a8-4315-b79c-ccc7617d75c0@gmail.com>

On Tue, 05 Sep 2023 20:07:16 PDT (-0700), gcc-patches@gcc.gnu.org wrote:
>
>
> On 9/5/23 20:33, Tsukasa OI wrote:
>
>> Internally we have this as:
>>>
>>> (TARGET_ZICOND || TARGET_XVENTANACONDOPS)
>>>
>>> I don't really care, so I'm happy to go with yours.
>
>> Because XVentanaCondOps instructions are only available on 64-bit target
>> (I wanted to prevent misuses because we don't reject XVentanaCondOps on
>> RV32), the target expression would be:
>>
>> (a) (TARGT_ZICOND || (TARGET_XVENTANACONDOPS && TARGET_64BIT))
>>
>> and I had three options to deal with it.
>>
>> 1.  Use the plain expression (a)
>> 2.  Name te expression (a)
>> 3.  Enable TARGET_XVENTANACONDOPS only on 64-bit target
>>
>> I think option 2 is the simplest yet understandable.
> Sure.  It may also give us the option to roll in some of the thead code
> at some point.  Their conditional move support seems to line up pretty
> well with zicond/xventanacondops too, though I haven't looked at it very
> deeply yet.

IIUC the T-Head stuff is actually a conditional move, so it's a little 
different than the conditional move/zero extensions (which IIUC have 
exactly the same semantics, just different encodings).   Hopefully the 
cmov fits in a bit easier, we shouldn't need to juggle the extra 0 
input.

>> I'm happy to hear that because I had no confidence so whether we can use
>> #include to share common parts.  I haven't tried yet but I believe we
>> have to #include only common parts (not including dg instructions
>> containing -march=..._zicond) so I will likely required to modify zicond
>> tests as well.
> You actually don't even have to break out the common parts.  The dg-
> directives in an included file aren't parsed by the dg framework.
>
>
>>
>> I'll submit PATCH v4 (not committing directly) as changes will be a bit
>> larger (and Jeff's words seem "near approval" even after fixing the
>> tests, not complete approval).
> Sounds perfect.  Given the bulk of the review work is already done, the
> final review ack will be easy.
>
> jeff

  reply	other threads:[~2023-09-06  3:16 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-30  6:44 [RFC PATCH] " Tsukasa OI
2023-08-30 22:54 ` [RFC PATCH v2 0/1] " Tsukasa OI
2023-08-30 22:54   ` [RFC PATCH v2 1/1] " Tsukasa OI
2023-09-05 12:10   ` [PATCH v3 0/1] " Tsukasa OI
2023-09-05 12:10     ` [PATCH v3 1/1] " Tsukasa OI
2023-09-06  0:17       ` Jeff Law
2023-09-06  2:33         ` Tsukasa OI
2023-09-06  3:07           ` Jeff Law
2023-09-06  3:16             ` Palmer Dabbelt [this message]
2023-09-06  5:47     ` [PATCH v4 0/1] " Tsukasa OI
2023-09-06  5:47       ` [PATCH v4 1/1] " Tsukasa OI
2023-09-06 14:04         ` Jeff Law

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=mhng-cd3c8f43-17ed-41b7-8a8e-5cb364a9a500@palmer-ri-x1c9 \
    --to=palmer@dabbelt.com \
    --cc=gcc-patches@gcc.gnu.org \
    --cc=research_trasio@irq.a4lg.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).