On Tue, 26 Feb 2019, Jakub Jelinek wrote: > On Sat, Feb 23, 2019 at 10:05:40AM +0100, Jakub Jelinek wrote: > > And finally, for 1) the patch has a case for a dead .ABNORMAL_DISPATCHER, > > one that has only incoming edges but no successors. I didn't want to > > complicate or slow down the processing too much, so it is actually done > > only if .ABNORMAL_DISPATCHER has no outgoing edges, rather than if it has > > some, but all of them are in the end to non-visited basic blocks. > > This means when we for 5) or 4) above remove all such bbs as dead in one > > cfg cleanup, we remove .ABNORMAL_DISPATCHER only in the following cfg > > cleanup. > > Thinking about the above, I think we could handle that cheaply in the same > cleanup cfg rather than in the next one. Don't know right now if we can > have at most one .ABNORMAL_DISPATCHER in a function or more (I vaguely > remember we disallow inlining in some of the ab cases like setjmp, > non-local goto etc.), if there can be at most one, we could just make > the .ABNORMAL_DISPATCHER visited normally, but additionally note it in some > basic_block pointer, if we can have more than one, we could have auto_vec of > them, and then after the loop just go through that one or more > .ABNORMAL_DISPATCHER bbs and if they don't have any successors visited, > unset the visited bit for them as well.
I think we can have multiple .ABNORMAL_DISPATCHERs - at least in theory via inlining, though I see code in the inliner avoiding multiple ones at least for nonlocal goto, not sure if that covers all cases. > Shall I modify the patch for that? Might it even simplify the patch? If not the only comment on the original patch is that it would be nice to test it on a SJLJ EH target ... Richard. > > 2019-02-23 Jakub Jelinek <ja...@redhat.com> > > > > PR tree-optimization/89280 > > * tree-cfgcleanup.c (maybe_dead_abnormal_edge_p, > > builtin_setjmp_setup_bb): New functions. > > (cleanup_control_flow_pre): Ignore maybe_dead_abnormal_edge_p edges. > > When visiting __builtin_setjmp_setup block, queue in special > > setjmp_vec vector edges from .ABNORMAL_DISPATCHER to corresponding > > __builtin_setjmp_receiver. > > > > * gcc.c-torture/compile/pr89280.c: New test. > > * gcc.dg/torture/pr57147-2.c: Don't expect a setjmp after noreturn > > function. Skip the test for -O0. > > Jakub > > -- Richard Biener <rguent...@suse.de> SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)
