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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/113189] New: `(-X * Y) * -X` can be optimized
 to `(X * Y) * X`
Date: Mon, 01 Jan 2024 09:39:38 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: tree-optimization
X-Bugzilla-Version: 14.0
X-Bugzilla-Keywords: missed-optimization, TREE
X-Bugzilla-Severity: enhancement
X-Bugzilla-Who: pinskia at gcc dot gnu.org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D113189

            Bug ID: 113189
           Summary: `(-X * Y) * -X` can be optimized to `(X * Y) * X`
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: missed-optimization, TREE
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

Take:
```
int f(int X, int Y)
{
        return (-X * Y) * -X;
}
double fd(double X, double Y)
{
        return (-X * Y) * -X;
}

int g(int X, int Y)
{
        return ((-X) << Y) * -X;
}
```

The negative should be optimized away but currently is only optimized at the
RTL level.=