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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/110941] [14 Regression] Dead Code Elimination
 Regression at -O3 since r14-2379-gc496d15954c
Date: Sat, 16 Sep 2023 07:46:25 +0000
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X-Bugzilla-Component: tree-optimization
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D110941

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
GCC 13:
Global Exported: _6 =3D [irange] unsigned int [0, 24] NONZERO 0x1e

trunk:
Global Exported: _6 =3D [irange] unsigned int [0, 24][+INF, +INF] MASK 0x1c=
 VALUE
0x0


And then:
Folding predicate _6 > 24 to 0

does not happen.
But what is interesting is with
https://gcc.gnu.org/pipermail/gcc-patches/2023-September/629128.html ,
We get:
```
Simplified relational if (_6 > 24)
 into if (_6 =3D=3D 4294967295)

Folded into: if (_6 =3D=3D 4294967295)
```

And then during cfgcleanup the match pattern:
/* X =3D=3D C (or X & Z =3D=3D Y | C) is impossible if ~nonzero(X) & C !=3D=
 0.  */
Hits which is totally funny because that means the range and nonzero
information are out of sync ...=