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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/110919] [14 Regression] Dead Code Elimination Regression at -O3 since r14-1691-gbc5a2c2e793
Date: Mon, 04 Sep 2023 05:53:44 +0000	[thread overview]
Message-ID: <bug-110919-4-Za9EIA8pzX@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-110919-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110919

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
For -O1 we have:
  _24 = c_16 == 0;
  _6 = (int) _24;
  _2 = (short int) _24;
  _3 = (int) _24;
  _5 = e;
  _20 = _3 == _5;
  _21 = c_16 != 0;
  _22 = _20 & _21;

((c_16 == 0) == _5) & (c_16 != 0)
((!b) ? 0 : 1) == _5 & (b)
(c_16 != 0) & (0 == _5)

This fixes -O1 (which didn't work before):

(simplify
 (bit_and:c zero_one_valued_p@0 (eq:c @1 (convert @2)))
 (with { bool wascmp; }
  (if (bitwise_inverted_equal_p (@0, @2, wascmp))
   (bit_and @0 (eq @1 { build_zero_cst (TREE_TYPE (@1)); })))))

But -O2 is still broken.

  parent reply	other threads:[~2023-09-04  5:53 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-06 11:05 [Bug tree-optimization/110919] New: " scherrer.sv at gmail dot com
2023-08-06 11:35 ` [Bug tree-optimization/110919] " scherrer.sv at gmail dot com
2023-08-06 16:55 ` pinskia at gcc dot gnu.org
2023-08-06 17:12 ` pinskia at gcc dot gnu.org
2023-08-20  9:11 ` pinskia at gcc dot gnu.org
2023-08-20 18:36 ` pinskia at gcc dot gnu.org
2023-08-20 18:41 ` pinskia at gcc dot gnu.org
2023-09-04  5:53 ` pinskia at gcc dot gnu.org [this message]
2023-09-04  6:09 ` pinskia at gcc dot gnu.org
2023-09-04  6:55 ` pinskia at gcc dot gnu.org
2024-03-07 23:26 ` law at gcc dot gnu.org
2024-05-07  7:41 ` [Bug tree-optimization/110919] [14/15 " rguenth at gcc dot gnu.org

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