[Bug tree-optimization/120211] [16 regression] ICE on valid code at -O3 with "-fno-tree-copy-prop -fno-tree-dominator-opts -fno-tree-loop-ivcanon -fno-tree-pre -fno-code-hoisting" on x86_64-linux-gnu: in gimple_phi_arg_def_from_edge, at gimple.h:4759

[yunboni at smail dot nju.edu.cn via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120211

Yunbo Ni <yunboni at smail dot nju.edu.cn> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |yunboni at smail dot nju.edu.cn

--- Comment #2 from Yunbo Ni <yunboni at smail dot nju.edu.cn> ---
There is a similar case that crashes at -O2: 

```c
int a, b, d;
void e() {
  do {
    int f = 0;
    while (1) {
      int c = a;
      for (; (c & 1) == 0; c = 1)
        for (; c & 1;)
          ;
      if (a)
        break;
      f++;
    }
    b = f & 5;
    if (b)
      break;
  } while (d++);
}
void main() {}
```

Bisected to
https://github.com/gcc-mirror/gcc/commit/9def392a1b63a198d15d972f73b4afc888389d7c