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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/105937] [12/13 Regression] maybe-uninitialized with std::optional
Date: Sun, 12 Jun 2022 22:25:29 +0000	[thread overview]
Message-ID: <bug-105937-4-WNqZEBy74a@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-105937-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105937

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |needs-reduction
   Target Milestone|---                         |12.2
            Summary|[12] Regression with        |[12/13 Regression]
                   |maybe-uninitialized         |maybe-uninitialized with
                   |                            |std::optional

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---

  # ttfRunIndex_64 = PHI <ttfRunIndex_6(52), [/app/example.cpp:207:27] 0(30)>
  # ttfRunIndex$8_65 = PHI <ttfRunIndex$8_8(52), [/app/example.cpp:207:27]
0(30)>
...


<L17>:
  [/app/example.cpp:213:13] if (ttfRunIndex$8_65 != 0)
    goto <bb 22>; [33.00%]
  else
    goto <bb 48>; [67.00%]

...

  <bb 22> [local count: 157594832]:
  [/app/example.cpp:216:62] len_15 = _20 - ttfRunIndex_64;

...
  # ttfRunIndex_6 = PHI <ttfRunIndex_14(D)(26), ttfRunIndex_64(48), _20(21),
ttfRunIndex_64(49)>
  # ttfRunIndex$8_8 = PHI <0(26), 0(48), [/app/example.cpp:227:29] 1(21),
1(49)>

So if anything this is both a missed optimization and the maybe uninitialized
predicates is not doing its job correctly.

  parent reply	other threads:[~2022-06-12 22:25 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-12 22:12 [Bug c++/105937] New: [12] Regression with maybe-uninitialized janisozaur+gcc at gmail dot com
2022-06-12 22:16 ` [Bug tree-optimization/105937] " pinskia at gcc dot gnu.org
2022-06-12 22:25 ` pinskia at gcc dot gnu.org [this message]
2022-10-11 12:06 ` [Bug tree-optimization/105937] [12 Regression] maybe-uninitialized with std::optional cvs-commit at gcc dot gnu.org
2022-10-11 12:08 ` rguenth at gcc dot gnu.org

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