https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102943
--- Comment #46 from Andrew Macleod <amacleod at redhat dot com> --- (In reply to Richard Biener from comment #44) > (In reply to Richard Biener from comment #43) > > (In reply to Andrew Macleod from comment #42) > > > (In reply to Richard Biener from comment #37) > > > > I'm looking at range_def_chain::m_def_chain, it's use is well > > > > obfuscated by > > > > inheritance but comments suggest that we have one such structure either > > > > for > > > > each edge in the CFG or for each basic-block. In particular this > > > > > > There is one structure per ssa-name globally. > > [...] > > > so its just O(ssa-name) already. > > > > so you mean O(num-ssa-names^2) since if it exists for each SSA name then > > we have m_def_chain (of length num-ssa-names) for each SSA name? That's > > what I originally feared, but I failed to find the array(?) that stores > > the range_def_chains. > > That is, I wondered what's the lifetime of the gori_compute : gori_map : > range_def_chain object(s), where they are allocated and/or freed and > maintained. I've seen m_bitmaps in range_def_chain which should be > of longer lifetime (maybe) for example. They all live and die as one with ranger. A gimple ranger object has a single ranger_cache: ranger_cache m_cache; Which is constructed when ranger is created, and the cache has a single gori_computer object: gori_compute m_gori; So they all have identical lifetimes.