https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71437
--- Comment #16 from rguenther at suse dot de <rguenther at suse dot de> --- On Fri, 3 Mar 2017, law at redhat dot com wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71437 > > Jeffrey A. Law <law at redhat dot com> changed: > > What |Removed |Added > ---------------------------------------------------------------------------- > Status|NEW |ASSIGNED > Assignee|unassigned at gcc dot gnu.org |law at redhat dot com > > --- Comment #15 from Jeffrey A. Law <law at redhat dot com> --- > So what looks real promising here. > > 1. Pull the "handle_dominating_asserts" bits out of tree-ssa-threadedge and > into tree-vrp.c. They really should have been there all along. > > 2. Improve DOM's handling of BIT_AND_EXPR/BIT_IOR_EXPR to avoid a couple minor > regressions due to #1. > > 3. Push some common code from tree-vrp.c/tree-ssa-dom.c into > tree-ssa-threadedge.c. > > 4. Change the random walk order for threading in tree-vrp.c to a domwalk I've experimented (not very thoroughly though) with doing the threading during substitute_and_fold via the vrp_fold_stmt callback which is now invoked from a domwalk. > 5. Record data from ASSERT_EXPRs during threading domwalk > > 6. Query the expression hash table in simplify_stmt_for_jump_threading That said, eventually organizing the non-backward threading as a domwalk that uses callbacks to record data / simplify stmts so that it can be used from VRP but also maybe from FRE or other passes that have a useful lattice would be nice. Not sure if all this is appropriate for GCC 7 though.
