public inbox for gcc-patches@gcc.gnu.org
 help / color / mirror / Atom feed
From: Jeff Law <jeffreyalaw@gmail.com>
To: "H.J. Lu" <hjl.tools@gmail.com>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] Ignore debug insns with CONCAT and CONCATN for insn scheduling
Date: Sat, 24 Sep 2022 14:37:26 -0600	[thread overview]
Message-ID: <93fb0c92-c6a4-450b-2d0a-eddd30543fae@gmail.com> (raw)
In-Reply-To: <CAMe9rOrTBDoCGqC+u90XBDfvRjPwYYJTqOhsqbJiNpSfpaE=Gg@mail.gmail.com>


On 9/21/22 16:11, H.J. Lu wrote:
> On Wed, Sep 7, 2022 at 10:03 AM Jeff Law via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
>>
>>
>> On 9/2/2022 8:36 AM, H.J. Lu via Gcc-patches wrote:
>>> CONCAT and CONCATN never appear in the insn chain.  They are only used
>>> in debug insn.  Ignore debug insns with CONCAT and CONCATN for insn
>>> scheduling to avoid different insn orders with and without debug insn.
>>>
>>> gcc/
>>>
>>>        PR rtl-optimization/106746
>>>        * sched-deps.cc (sched_analyze_2): Ignore debug insns with CONCAT
>>>        and CONCATN.
>> Shouldn't we be ignoring everything in a debug insn?   I don't see why
>> CONCAT/CONCATN are special here.
> Debug insns are processed by insn scheduling.   I think it is to improve debug
> experiences.  It is just that there are no matching usages of CONCAT/CONCATN
> in non-debug insns.

But from a dependency standpoint ISTM all debug insn can be ignored.  I 
still don't see why concat/concatn should be special here.


jeff



  reply	other threads:[~2022-09-24 20:37 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-02 14:36 H.J. Lu
2022-09-07 17:02 ` Jeff Law
2022-09-21 22:11   ` H.J. Lu
2022-09-24 20:37     ` Jeff Law [this message]
2022-09-26 19:52       ` H.J. Lu
2022-09-26 23:23         ` Jeff Law
2022-09-26 23:43           ` Jakub Jelinek
2022-09-27  1:40             ` 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=93fb0c92-c6a4-450b-2d0a-eddd30543fae@gmail.com \
    --to=jeffreyalaw@gmail.com \
    --cc=gcc-patches@gcc.gnu.org \
    --cc=hjl.tools@gmail.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).