[Bug middle-end/94146] [10 Regression] Merging functions with same bodies stopped working

["rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94146

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #3)
> If not already marked clearly as an ICF created thunk, I'd say it should be
> and then inliner should take it into account (and only inline if the
> function became very small or not at all).

It looks like ICF really creates a forwarding call:

ternary2 (int i)
{
  int retval.4;

  <bb 2> [local count: 1073741824]:
  retval.4_3 = ternary (i_2(D)); [tail call]
  return retval.4_3;

}

so IMHO for small functions the inlining is good (but why don't we create
an alias or an alternate entry symbol instead of a full (aligned) function?)

For big functions the inlining shouldn't happen indeed, possibly by detecting
this kind of forwarders?

So we're missing a testcase showing the regression IMHO.  It still works
with -Os for the testcase.