[Bug tree-optimization/120081] New: lsplit is not always working

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120081

            Bug ID: 120081
           Summary: lsplit is not always working
           Product: gcc
           Version: 16.0
            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 at -O3:
```
void f();
void g (unsigned n)
{
  for (unsigned i = n; i < 30; ++i)
    if (i > 10)
      f();
}
void g1 (unsigned n)
{
  unsigned i = n;
  for (; i <= 10 && i < 30; ++i)
  ;
  for (; i < 30; ++i)
    //if (i > 10)
      f();
}
```

I had assumed g would transform into g1 but currently it is not.

This is derived from gcc.dg/Wrestrict-22.c .