From: "H.J. Lu" <hjl.tools@gmail.com>
To: Jeff Law <jeffreyalaw@gmail.com>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] Ignore debug insns with CONCAT and CONCATN for insn scheduling
Date: Mon, 26 Sep 2022 12:52:08 -0700 [thread overview]
Message-ID: <CAMe9rOqbw+DeDP_kOPvvtXxzKUoNAyjsn3dMGwX=p4wscAu4WQ@mail.gmail.com> (raw)
In-Reply-To: <93fb0c92-c6a4-450b-2d0a-eddd30543fae@gmail.com>
On Sat, Sep 24, 2022 at 1:37 PM Jeff Law <jeffreyalaw@gmail.com> wrote:
>
>
> 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.
>
I tried to ignore everything in a debug insn. It caused many regressions in
the GCC testsuite.
--
H.J.
next prev parent reply other threads:[~2022-09-26 19:52 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
2022-09-26 19:52 ` H.J. Lu [this message]
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='CAMe9rOqbw+DeDP_kOPvvtXxzKUoNAyjsn3dMGwX=p4wscAu4WQ@mail.gmail.com' \
--to=hjl.tools@gmail.com \
--cc=gcc-patches@gcc.gnu.org \
--cc=jeffreyalaw@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).