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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/111523] Unexpected performance regression with -ftrivial-auto-var-init=zero for e.g. systemctl unmask
Date: Fri, 01 Mar 2024 07:57:16 +0000	[thread overview]
Message-ID: <bug-111523-4-hJd15c6Po3@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-111523-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111523

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Sam James from comment #3)
>     manager_deserialize takes ~1s instead of ~0.2s

I looked into manager-serialize.c and its code generation with and without
-ftrivial-auto-var-init=zero and there is no obvious issues there. 

The only major thing I saw different was:
  MEM <unsigned long> [(void *)&__unique_prefix_i12] = 4294967294;

vs
  __unique_prefix_i12.idx = 4294967294;

where idx is of type unsigned.

that is -2 aka _IDX_ITERATOR_FIRST.

There is padding after the idx field so storing zero there is fine.

  parent reply	other threads:[~2024-03-01  7:57 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-21 16:40 [Bug middle-end/111523] New: " hp at gcc dot gnu.org
2023-09-21 16:49 ` [Bug middle-end/111523] " sjames at gcc dot gnu.org
2024-02-29 19:19 ` qinzhao at gcc dot gnu.org
2024-03-01  0:12 ` sjames at gcc dot gnu.org
2024-03-01  1:25 ` pinskia at gcc dot gnu.org
2024-03-01  5:15 ` pinskia at gcc dot gnu.org
2024-03-01  7:57 ` pinskia at gcc dot gnu.org [this message]
2024-03-01  8:23 ` pinskia at gcc dot gnu.org
2024-03-01  8:38 ` pinskia at gcc dot gnu.org
2024-03-07  6:45 ` pinskia at gcc dot gnu.org
2024-03-13 14:01 ` qinzhao at gcc dot gnu.org

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