[Bug tree-optimization/102131] [12 Regression] wrong code at -O1 and above on x86_64-linux-gnu

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102131

--- Comment #3 from Jiu Fu Guo <guojiufu at gcc dot gnu.org> ---
The issue may come from 'iv0 cmp iv1' transform:

   if (c<b) exit-loop
-->if (c>=b) in-loop
-->if (b<=c) in-loop

  c: {4, +, 3}
  b: {1, +, 1}

  if ({1, +, 1} <= {4, +, 3})
  ==> if ({1,+,-2} <= {4,+,0}) //// here, error occur
  ==> if ({1,+,-2} < {5,+,0}) le-->lt