On Fri, Mar 25, 2016 at 1:33 AM, Andrew Sutton <andrew.n.sut...@gmail.com> wrote: > I'll just leave this here... > > This patch significantly improves performance with concepts (i.e., > makes it actually usable for real systems) and improves the > specificity of diagnostics when constraints fail. > > Unfortunately, this isn't easily submittable in small pieces because > it completely replaces most of the core processing routines for > constraints, including (essentially) a complete rewrite of logic.cc > and the diagnostics in constraint.cc. More perfective work could be > done related to diagnostics, but this needs to be applied first. > > As part of the patch, I added timevars for constraint satisfaction and > subsumption. In template-heavy coe (~80KLOC), I'm seeing satisfaction > account for ~6% of compilation time and subsumption ~2%. Template > instantiation remains ~35%, but I think there's still room for > improvement in concepts. It just requires experimentation. > > Tests involving significant number of disjunctions have yet to > register > 1% of compilation time spent in subsumption, but I'm still > testing.
Thanks, I've been working on integrating this patch, hoping to have it in for 6.2. Have you done more work on it since you sent this out? A few issues: I've run into some trouble building cmcstl2: declarator requirements on a function can lead to constraints that tsubst_constraint doesn't handle. What was your theory of only handling a few _CONSTR codes there? This is blocking me from checking in the patch. Adding gcc_unreachable to the ARGUMENT_PACK_SELECT handling in concept arg hash/compare doesn't seem to break anything in either the GCC testsuite or your stl2. Do you have a testcase where that code is still needed? > Also, it might be worth noting that partial specialization of variable > templates is currently broken. We don't seem to be emitting template > arguments as part of the mangled name, leading to lots and lots of > late redefinition errors. This should be fixed now. Jason
