[Bug tree-optimization/92768] [8/9/10 Regression] Maybe a wrong code for vector constants

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92768

--- Comment #12 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to rguenther@suse.de from comment #11)
> Alternatively add another flag to operand_equal_p to say whether
> exact literal equality is asked for.

That is fine with me.  Though, as I said on IRC, it can work then by accident,
but might break any time, e.g. won't VN if it sees with -fno-signed-zeros:
  _2 = { 0.f, 0.f, 0.f, 0.f };
  use (_2);
  ...
  _5 = { 0.f, -0.f, 0.f, -0.f };
  use (_5);
happily replace _5 with _2, or anything else that uses operand_equal_p and
won't pass this new magic flag?