[Bug tree-optimization/114230] Missed optimization of loop deletion: `a!=0`

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114230

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
            Summary|Missed optimization of loop |Missed optimization of loop
                   |deletion: a=0||a            |deletion: `a!=0`
                 CC|                            |pinskia at gcc dot gnu.org
           Keywords|                            |missed-optimization
           Severity|normal                      |enhancement
   Last reconfirmed|                            |2024-03-05

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed.
we have:
```
  <bb 3> [local count: 1063004408]:
  # i_11 = PHI <i_8(5), 0(2)>
  # a_lsm.4_13 = PHI <_3(5), a_lsm.4_5(2)>
  _2 = a_lsm.4_13 != 0;
  _3 = (int) _2;
  i_8 = i_11 + 1;
  if (i_8 != 100000)
    goto <bb 5>; [98.99%]
  else
    goto <bb 4>; [1.01%]

  <bb 5> [local count: 1052266995]:
  goto <bb 3>; [100.00%]
```

Which sccp does not handle `(int)a != 0` currently. It does handle `a|=b;`,
`a^=b;`, and `a&=b;` though.