Ping again... Thanks.
---------------------------------------- > From: bernd.edlin...@hotmail.de > To: hubi...@ucw.cz > CC: gcc-patches@gcc.gnu.org; richard.guent...@gmail.com > Subject: [PING] [PATCH] Fix PR ipa/61190, 2nd edition > Date: Tue, 14 Oct 2014 11:40:56 +0200 > > Ping... > > see: https://gcc.gnu.org/ml/gcc-patches/2014-10/msg00536.html > >> Hi Honza, >> >> >> as you know, we have a wrong code bug, when a pure or const method is called >> via a virtual thunk. >> I had some more Ideas, how to fix that, but all of them had some serious >> draw-backs, so I leave the details out... >> >> >> But now I have a new insight, why the "obvious" fix for this serious code >> generation bug did not work >> in the first place. >> >> >> And the reason was, that if ipa-pure-const.c calls set_const_flag or >> set_pure_flag for a thunk, it calls the same >> function later for the called method, and this overwrites the flags of _all_ >> associated thunks and aliases. >> However that should at least not be done for virtual thunks, as these need >> to be IPA_NEITHER, even if >> the method itself has different attributes, that is because the assembler >> thunk accesses the vtable, while >> other thunks do not. >> >> >> So I re-factored set_const_flag and set_pure_flag to exclude the virtual >> thunks, taking care that other >> users of call_for_symbol_thunks_and_aliases do not get a different behavior >> than before this patch. >> >> >> The attached patch was boot-strapped and >> regression-tested on x86_64-linux-gnu. >> Ok for trunk? >> >> >> PS: As a side-note, there are two identical functions, named >> "call_for_symbol_and_aliases", in >> class symtab_node and in class cgraph_node, which inherits from symtab_node. >> Both functions are >> not declared virtual. Is that what's intended? Usually this could lead to >> errors, or at least some serious >> compiler warnings. >> >> >> Thanks >> Bernd. >> >
