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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/113458] Missed SLP for reduction of
 multiplication/addition with promotion
Date: Wed, 17 Jan 2024 21:08:49 +0000
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X-Bugzilla-Component: tree-optimization
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D113458

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The loop based vectorizer is able to do a decent job at:
```
int f(short *a, signed char *b, int n)
{
        int sum =3D 0;
        n =3D 8;
        for(int i =3D 0;i < n; i++)
          sum +=3D a[i]*b[i];
        return sum;
}
```

But if we reduce n to 4, the loop based vectorizer is not able to handle it
either.=