[Bug middle-end/115607] New: missed tail call with large structure size

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115607

            Bug ID: 115607
           Summary: missed tail call with large structure size
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---
            Target: aarch64-linux-gnu arm-linux-gnu powerpc{,64}-linux-gnu

Take:
```
typedef struct Foo {
  int a, b, c, d, e, f, g, h;
}Foo;

Foo
callee (int i);

Foo 
caller (int i)
{
  return callee (i + 1);
}
```

This can be tail called but currently we don't.
The issue is tail calls for functions where the structure return is passed via
pointer via register is not tail called.