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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/100112] missed optimization for dead code
 elimination at -O3, -Os (vs. -O1, -O2)
Date: Mon, 27 Sep 2021 07:31:26 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D100112

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
So the point is that

int *c, *b;
void foo()
{
  int *tem =3D b;
  *tem =3D 0;
  int *tem2 =3D c;
  c =3D tem2;
}

and

int *c, *b;
void foo()
{
  int *tem =3D b;
  int *tem2 =3D c;
  *tem =3D 0;
  c =3D tem2;
}

are different but we encode tem2 =3D c; the same in the hashtable with
strict-aliasing.=