https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105346
--- Comment #11 from Andrew Macleod <amacleod at redhat dot com> --- (In reply to Richard Biener from comment #6) > > <bb 2> : > bufp_2 = &buf; > if (&buf != bufp_2) > goto <bb 3>; [INV] > else > goto <bb 4>; [INV] > > <bb 3> : > __builtin_free (bufp_2); > > and for the stmt __builtin_free (bufp_2) I'd like to ask if we know > that bufp_2 is != &buf (I'd expect a 'true' answer). I think the > relation oracle should be able to answer this but I can't find the > appropriate API to use for this? - The relation oracle currently only works with ssa-names. - Ranger also doesn't currently track that sort of symbolic equivalence with irange. - the VRP passes have a pointer tracking mechanism as part of the dom walk, and the call to rvrp_folder::value_of_expr (bufp_2) would give us &buf. I also think we also would fold the stmt in VRP. This could in theory be extended to any pass doing a dom walk. however: - I believe the upcoming prange extension for pointer ranges in stage 1 will make this happen naturally with rangers query system. range_of_stmt ( if <..>) would then produce bool [0, 0]. I would also expect that prange will have an easy way to ask what its base/equivalence(s) are.
