[Bug tree-optimization/100162] missed optimization for dead code elimination at -O3 (vs. -O2)

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100162

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |needs-bisection

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
FRE is no longer able to optimize _7 to 2 in GCC 13+:
  c[0][b.1_1] = 2;
  c[1][b.1_1] = 2;
  c[2][b.1_1] = 2;
  c[3][b.1_1] = 2;
  c[4][b.1_1] = 2;
  a = 5;
  _5 = b.1_1 != 0;
  _6 = (int) _5;
  _7 = c[0][0];

Of course -O3 reasons why is listed below.