On 01/03/2012 09:42 PM, Torvald Riegel wrote: >> Why does the explicit CFG approach not work exactly? cfun->calls_setjmp is >> thought to be quite a big hammer. > > I don't know, actually. When I looked at the miscompilation case, all > abnormal edges seemed to be in place. > > @rth: Do you have an idea what could be going wrong? I haven't tried > the other thing you sent me, what was it supposed to fix?
There are several places where those edges (currently) get lost going from gimple to rtl. In addition, return value copy from the hard reg to the pseudo is in the wrong basic block wrt the abnormal edges. My inclination at this point is to use returns_twice for the 4.7 release and fix the abcall edges and associated fiddlery in 4.8 stage1. I'm not especially confident that we'd clear out all the bugs in time otherwise. r~
