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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/110515] [12/13/14 Regression] llvm-15.0.7 possibly
 invalid code on -O3
Date: Sat, 01 Jul 2023 23:32:49 +0000
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X-Bugzilla-Keywords: alias, wrong-code
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D110515

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |alias

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I am not 100% sure but I think the problem is related to this code (note I
added that asm comment there):
```
    V *P =3D u.i;
    V *E =3D P + InlineSlots;
    for (; P !=3D E; ++P) {
        if (P->v !=3D EmptyKey) {
            TmpEnd->v =3D P->v;
            ++TmpEnd;
        }
    }

    Small =3D false;
    //asm("":"+m"(*this)::"memory");
    u.o =3D LargeRep{new V[128], 128};
```

The problem is most likely the read from u.i is happening after the store to
u.o.=