> On January 21, 2020 4:37:31 PM GMT+01:00, Jan Hubicka <hubi...@ucw.cz> wrote: > >Hi, > >this patch fixes ICE causes by call stmt site hash going out of sync. > >For > >speculative edges it is assumed to contain a direct call so if we are > >removing it hashtable needs to be updated. I realize that the code is > >ugly > >but I will leave cleanup for next stage1. > > > >Bootstrapped/regtested x86_64-linux. This patch makes it possible to > >build > >Firefox again. > > It even looks quadratic? Can't you simply lookup the stmt?
I am not sure what you mean by looking up the stmt. To go from stmt to call edge you either walk the callees chain or use call_site_hash that populates itself when you have more than 100 callees. The situation this code solves is that with speculative calls have multiple direct edges, one indirect and multiple refs associated with the speculated call stmt. Now one of direct edges gets removed and at this moment one needs to look up different one to re-populate the hash. I meant to fix the ICE first, but indeed resolve_speuclations and redirect_stmt_to_callee is O(num_callees+num_refs) in worst case here which needs to be fixed (though the case is quite rare in practice). One can keep direct edges in a block in the lists (with verifier help), but still looking up referneces is bit hard since they are in vector and that is re-numbered on inserts and deletes. I plan to fix this incrementally (we want also refs hash and verifier for the caches, plus this all is memory use critical) Honza
