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: Mon, 26 Sep 2022 17:23:45 -0600 [thread overview]
Message-ID: <fcaf3d36-2076-8846-6413-7441557794ae@gmail.com> (raw)
In-Reply-To: <CAMe9rOqbw+DeDP_kOPvvtXxzKUoNAyjsn3dMGwX=p4wscAu4WQ@mail.gmail.com>
On 9/26/22 13:52, H.J. Lu wrote:
> 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.
Not terribly useful -- what failed and why?
jeff
next prev parent reply other threads:[~2022-09-26 23:23 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
2022-09-26 23:23 ` Jeff Law [this message]
2022-09-26 23:43 ` Jakub Jelinek
2022-09-27 1:40 ` Jeff Law
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