On Fri, Apr 29, 2016 at 2:09 PM, Peter Bergner <berg...@vnet.ibm.com> wrote: > On Fri, 2016-04-29 at 11:56 +0200, Richard Biener wrote: >> Your testcase passes '2' where it passes just fine. If I pass 3 as which >> I indeed get an abort () but you can't reasonably expect it to return 13 >> then. > > Bah, I added an extra case and didn't change the argument. :-( > Let me fix that and then dig into the current behavior. > > > >> So I fail to see the actual bug you are fixing and I wonder why you do stuff >> at the GIMPLE level when we only remove the unreachable blocks at RTL >> level CFG cleanup. Iff then the "fix" should be there. > > I actually started out trying to fix the problem in rtl first, but > ran into multiple problems, which at the time made it seem like > fixing this at the GIMPLE level was a better solution. > > > >> But as said, the behavior is expected - in fact the jump-table code should >> be optimized for a unreachable default case to simply omit the range >> check! That would be a better fix (also avoiding the wild branch). > > I know I've seen the wild branch due to normal case statements having > __builtin_unreachable() too, so it's not just a default case problem. > That said, I'll have a look to see whether we can fix unreachable > normal case statements too. Thanks.
Again, the wild jump is not a bug but at most a missed optimization (to remove it). Richard. > Peter > >
