On Tue, Nov 01, 2016 at 09:41:20AM -0400, Jason Merrill wrote: > On Tue, Oct 25, 2016 at 9:59 AM, Marek Polacek <pola...@redhat.com> wrote: > > On Mon, Oct 24, 2016 at 04:10:21PM +0200, Marek Polacek wrote: > >> On Thu, Oct 20, 2016 at 12:28:36PM +0200, Marek Polacek wrote: > >> > I found a problem with this patch--we can't call > >> > do_warn_duplicated_branches in > >> > build_conditional_expr, because that way the C++-specific codes might > >> > leak into > >> > the hasher. Instead, I should use operand_equal_p, I think. Let me > >> > rework > >> > that part of the patch. > > Hmm, is there a reason not to use operand_equal_p for > do_warn_duplicated_branches as well? I'm concerned about hash > collisions leading to false positives.
If the hashing function is iterative_hash_expr / inchash::add_expr, then that is supposed to pair together with operand_equal_p, we even have checking verification of that. Jakub