[Bug d/101691] New: d: Use of LOOP_EXPR prevents removing no-op loops.

[ibuclaw at gdcproject dot org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101691

            Bug ID: 101691
           Summary: d: Use of LOOP_EXPR prevents removing no-op loops.
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: d
          Assignee: ibuclaw at gdcproject dot org
          Reporter: ibuclaw at gdcproject dot org
  Target Milestone: ---

As observed on compiler explorer.

https://d.godbolt.org/z/eM8Pv91eT

The C, C++ (and Fortran?) front-ends lower loops as labels and gotos, which
*is* optimized away.

https://godbolt.org/z/8Yz9oqx63

---
void fun(int a, int b, int step) 
{
    for (int i = a; i < b; i += step) {
    }
}