[Bug tree-optimization/112627] New: `(a + c) - b == c` is not optimized to `a == b`

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112627

            Bug ID: 112627
           Summary: `(a + c) - b == c` is not optimized to `a == b`
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

Take:
```
int f(int a, int b, int c)
{
  return (a + c) - b == c;
}
int f1(int a, int b, int c)
{
  return (a + 1) - b == 1;
}
```

GCC can optimize f1 but not f. Note f1 is only optimized at the RTL level even.