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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/111542] New: [11/12/13/14 Regression]
Date: Fri, 22 Sep 2023 18:51:13 +0000	[thread overview]
Message-ID: <bug-111542-4@http.gcc.gnu.org/bugzilla/> (raw)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111542

            Bug ID: 111542
           Summary: [11/12/13/14 Regression]
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

Take:
```
_Bool f(int x,int y)
{
  _Bool a = x == 0;
  _Bool b = y == 0;
  _Bool t = a & b;
  return t & !a;
}

```

This used to optimize to 0 in GCC 6 but starting with GCC 7, we get:
```
  _5 = x_2(D) | y_3(D);
  _6 = _5 == 0;
  _1 = x_2(D) != 0;
  _7 = _1 & _6;
```

             reply	other threads:[~2023-09-22 18:51 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-22 18:51 pinskia at gcc dot gnu.org [this message]
2023-09-22 18:54 ` [Bug tree-optimization/111542] " pinskia at gcc dot gnu.org
2023-09-22 18:55 ` [Bug tree-optimization/111542] [11/12/13/14 Regression] (a==0)&(b==0) into `(a|b) == 0` optimization sometimes gets in the way of other optimizations pinskia at gcc dot gnu.org
2023-09-23 20:14 ` pinskia at gcc dot gnu.org
2023-09-23 20:23 ` pinskia at gcc dot gnu.org
2023-10-17 13:00 ` rguenth at gcc dot gnu.org
2024-05-07  7:42 ` [Bug tree-optimization/111542] [11/12/13/14/15 " rguenth at gcc dot gnu.org

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