On Mon, 2016-11-28 at 14:44 -0700, Jeff Law wrote: > On 11/23/2016 04:55 PM, Segher Boessenkool wrote: > > Combine can turn a conditional trap into an unconditional trap. If > > it > > does that it should make the code after it unreachable (an > > unconditional > > trap should be the last insn in its bb, and that bb has no > > successors). > > > > This patch seems to work. It is hard to be sure, this is very hard > > to > > trigger. Quite a few other passes look like they need something > > similar > > as well, but I don't see anything else handling it yet either. > > > > How does this look? Any better ideas? > It's probably a reasonable place to start as there's lots of > similarities to converting a conditional branch to an unconditional. > Like you I worry there may be other instances of this issue may be > lurking. > > The possibility of having a conditional trap in the IL turn into an > unconditional trap has always been there. As you note, it's somewhat > difficult to trigger since the SSA optimizers ought to > expose/optimize > this long before we get to RTL.
Could the RTL frontend be of use here?
